Sample records for positron lifetime measurements

  1. On the method of positron lifetime measurement

    NASA Technical Reports Server (NTRS)

    Nishiyama, F.; Shizuma, K.; Nasai, H.; Nishi, M.

    1983-01-01

    A fast-slow coincidence system was constructed for the measurement of positron lifetimes in material. The time resolution of this system was 270 ps for the (60)Co gamma rays. Positron lifetime spectra for 14 kinds of alkali halides were measured with this system. Two lifetime components and their intensities were derived from analyses of the lifetime spectra.

  2. Positron lifetime measurements by proton capture F. A. Selim,a

    E-print Network

    Collins, Gary S.

    Positron lifetime measurements by proton capture F. A. Selim,a D. P. Wells, and J. F. Harmon December 2004; published online 22 February 2005 A positron lifetime spectroscopy PLS technique coincident MeV rays, allowing positron lifetime to be measured. One quantum provides a start signal

  3. A new way of using positron-lifetime measurements to study lattice defects

    E-print Network

    Boyer, Edmond

    39 A new way of using positron-lifetime measurements to study lattice defects Ch. Janot, B. George). Abstract. 2014 With the aim of extending positron-lifetime measurements to high temperature and avoiding surface and source contributions, experiments have been performed with positron emitting isotopes

  4. Positron annihilation lifetime measurement of irradiated stainless steels

    NASA Astrophysics Data System (ADS)

    Kuramoto, E.; Tsukuda, N.; Aono, Y.; Takenaka, M.; Takano, Y.; Yoshida, H.; Shiraishi, K.

    1985-08-01

    Two types of austenitic stainless steels (316SS and JPCA) and two types of ferritic/martensitic stainless steels (HT-9 and JFMS) were irradiated by high energy electrons at 77 K and positron annihilation lifetime measurements were carried out to obtain the isochronal annealing behaviour above room temperature. The main decrease of the intensity of the second component, namely, the migration of vacancies to sinks was observed at 250°C for austenitic stainless steels and at 150°C for ferritic/martensitic stainless steels. By assuming the number of jumps to sinks as 10 3, the vacancy migration energy was obtained as 1.36 and 1.10 eV for austenitic and ferritic/martensitic stainless steels, respectively. This result was used to discuss the low swelling behaviour of the ferritic/martensitic stainless steels.

  5. Nondestructive monitoring of fatigue damage evolution in austenitic stainless steel by positron-lifetime measurements

    Microsoft Academic Search

    Uwe Holzwarth; Petra Schaaff

    2004-01-01

    Positron-lifetime measurements have been performed on austenitic stainless steel during (i) stress- and (ii) strain-controlled fatigue experiments for different applied stress and strain amplitudes, respectively. For this purpose a generator-detector assembly with a 72Se\\/72As positron generator [maximum activity 25 muCi (0.9 MBq)] has been mounted on mechanical testing machines in order to measure the positron lifetime without removing the specimens

  6. Positron Lifetimes in Metals

    Microsoft Academic Search

    Howard Weisberg; Stephan Berko

    1967-01-01

    Positron decay curves in various metals have been measured, using careful sample preparation techniques and a delayed-coincidence system with 0.30-nsec (full width at half-maximum) prompt time resolution and 104:1 peak-to-background ratio. Evidence was found that the annihilation in pure metals under ideal conditions is characterized by a single exponential decay, the second lifetime usually observed being an artifact of sample

  7. PHYSICAL REVIEW B 88, 174102 (2013) Positron lifetime measurements of hydrogen passivation of cation vacancies

    E-print Network

    McCluskey, Matthew

    2013-01-01

    of cation vacancies in yttrium aluminum oxide garnets F. A. Selim,1,* C. R. Varney,1 M. C. Tarun,1 M. C oxides based on positron lifetime measurements, infrared spectroscopy, and composition analysis. Defects were characterized in samples of yttrium aluminum garnet grown in O2 or Ar. However, no positron

  8. Positron lifetime measurements as a non-destructive technique to monitor fatigue damage

    Microsoft Academic Search

    Byrne

    1975-01-01

    In the fatigue cycling of initially hard copper, self consistent ; positron lifetime and x-ray particle size measurements followed the softening ; process and revealed a new feature which may be the final development of ; microvoids before fracture. In the cyclic fatigue of initially soft 4340 steel ; closely spaced concurrent measurements of these parameters are now in progress.

  9. Tomographic Positron Annihilation Lifetime Spectroscopy

    NASA Astrophysics Data System (ADS)

    Wagner, A.; Anwand, W.; Butterling, M.; Fiedler, F.; Fritz, F.; Kempe, M.; Cowan, T. E.

    2014-04-01

    Positron annihilation lifetime spectroscopy serves as a perfect tool for studies of open-volume defects in solid materials such as vacancies, vacancy agglomerates, and dislocations. Moreover, structures in porous media can be investigated ranging from 0.3 nm to 30 nm employing the variation of the Positronium lifetime with the pore size. While lifetime measurements close to the material's surface can be performed at positron-beam installations bulk materials, fluids, bio-materials or composite structures cannot or only destructively accessed by positron beams. Targeting those problems, a new method of non-destructive positron annihilation lifetime spectroscopy has been developed which features even a 3-dimensional tomographic reconstruction of the spatial lifetime distribution. A beam of intense bremsstrahlung is provided by the superconducting electron linear accelerator ELBE (Electron Linear Accelerator with high Brilliance and low Emittance) at Helmholtz-Zentrum Dresden-Rossendorf. Since the generation of bremsstrahlung and the transport to the sample preserves the sharp timing of the electron beam, positrons generated inside the entire sample volume by pair production feature a sharp start time stamp for lifetime studies. In addition to the existing technique of in-situ production of positrons inside large (cm3) bulk samples using high-energy photons up to 16 MeV from bremsstrahlung production, granular position-sensitive photon detectors have been employed. The detector system will be described and results for experiments using samples with increasing complexity will be presented. The Lu2SiO5:Ce scintillation crystals allow resolving the total energy to 5.1 % (root-mean-square, RMS) and the annihilation lifetime to 225 ps (RMS). 3-dimensional annihilation lifetime maps have been created in an offline-analysis employing well-known techniques from PET.

  10. Miscibility and phase separation in SAN\\/PMMA blends investigated by positron lifetime measurements

    Microsoft Academic Search

    G. N. Kumaraswamy; C. Ranganathaiah; M. V. Deepa Urs; H. B. Ravikumar

    2006-01-01

    Miscibility and phase separation in SAN\\/PMMA blends have been investigated using DSC, IR spectroscopy and positron lifetime spectroscopy (PLS). Single broad glass transition observed throughout the blend compositions, may be due to overlap of two glass transitions. IR measurements clearly indicate the absence of strong interactions. This supports miscibility is due to intramolecular repulsive forces in the SAN component. On

  11. Investigation of vacancy defect in InP crystal by positron lifetime measurement

    Microsoft Academic Search

    Niefeng Sun; Luhong Mao; Weidong Mao; Hezou Wang; Xiang Wu; Keyun Bi; Zhengping Zhao; Weilian Guo; Xiawan Wu; Xiaolong Zhou; Bingke Chen; Yanjun Zhao; Kewu Yang; Tongnian Sun

    2008-01-01

    Positron lifetime measurements have been carried out on liquid-encapsulated Czochralski-grown undoped InP samples sliced from the middle part of ingots over the temperature range 10–300K. And at 70K, the spectra have been measured in darkness, under illumination of infrared LED, and with illumination off is one sample. The measurements at low temperature reveal different concentration of hydrogen indium vacancy complex

  12. Positron annihilation lifetime measurements of austenitic stainless and ferritic/martensitic steels irradiated in the SINQ target irradiation program

    NASA Astrophysics Data System (ADS)

    Sato, K.; Xu, Q.; Yoshiie, T.; Dai, Y.; Kikuchi, K.

    2012-12-01

    Titanium-doped austenitic stainless steel (JPCA) and reduced activated ferritic/martensitic steel (F82H) irradiated with high-energy protons and spallation neutrons were investigated by positron annihilation lifetime measurements. Subnanometer-sized (<˜0.8 nm) helium bubbles, which cannot be observed by transmission electron microscopy, were detected by positron annihilation lifetime measurements for the first time. For the F82H steel, the positron annihilation lifetime of the bubbles decreased with increasing irradiation dose and annealing temperature because the bubbles absorb additional He atoms. In the case of JPCA steel, the positron annihilation lifetime increased with increasing annealing temperature above 773 K, in which case the dissociation of complexes of vacancy clusters with He atoms and the growth of He bubbles was detected. He bubble size and density were also discussed.

  13. Free-Radical Quenching of Positron Lifetimes

    Microsoft Academic Search

    Stephan Berko; A. Joseph Zuchelli

    1956-01-01

    The annihilation lifetime of positrons stopping in benzene has been measured as a function of the percentage of added free radical, diphenylpicrylhydrazyl. The long component of the complex annihilation curve quenches from 2.67×10-9 sec in pure benzene to 5.3×10-10 sec at a 3% free radical concentration. An annihilation model following Bell and Graham's assumptions is discussed, postulating the partial formation

  14. Positron lifetime spectroscopy in thin polymer coatings

    NASA Technical Reports Server (NTRS)

    Singh, Jag J.; Eftekhari, Abe; Sprinkle, Danny R.

    1990-01-01

    Polymer coatings are finding increasing applications in aerospace industry. The effectiveness of coatings depends strongly on their microstructure and adhesion to the substrates. Currently, there is no technique for adequately monitoring the quality of the coatings. We adapted positron lifetime spectroscopy for the investigation of thin coatings. Results of measurements on 0.001-in-thick polyurethane coatings on aluminum and steel substrates and thicker (0.080-in.) self-standing polyurethane discs were compared. In all cases, we find positron lifetime groups centered around 560 ps, corresponding to the presence of 0.9 A exp 3 free volume cells. However, the number of free volume cells in thin coatings is larger, suggesting that the morphology of thin coatings is different from that of bulk polyurethane. These results and their structural implications are discussed.

  15. Positron beam lifetime spectroscopy at Lawrence Livermore National Laboratory

    SciTech Connect

    Howell, R.H.; Cowan, T.E.; Hartley, J.H. [Lawrence Livermore National Lab., CA (United States); Stern, P.A. [Lawrence Livermore National Lab., CA (United States)]|[California Univ., Davis, CA (United States). Dept. of Physics

    1996-10-01

    Defect analysis is needed for samples ranging in thickness from thin films to large engineering parts. We are meeting that need with two positron beam lifetime spectrometers: on on a 3 MeV electrostatic accelerator and the second on our high current linac beam. The high energy beam spectrometer performs positron lifetime analysis on thick samples which can be encapsulated for containment or for in situ measurements in controlled environments. At our high current beam, we are developing a low energy, microscopically focused, pulsed positron beam to enable positron annihilation lifetime spectroscopy for defect specific, 3-D maps with sub-micron location resolution. The data from these instruments with the aid of first principles calculations of defect specific positron lifetimes.

  16. Detection of interstitial clusters in neutron irradiated Ni?Hf alloy by perturbed angular correlation and positron annihilation lifetime measurements

    NASA Astrophysics Data System (ADS)

    Okazawa, H.; Yoshiie, T.; Ishizai, T.; Sato, K.; Xu, Q.; Satoh, Y.; Ohkubo, Y.; Kawase, Y.

    2004-08-01

    In order to understand the effect of alloying elements on the damage structure evolution in metals, defect clusters near Hf in Ni were studied using the perturbed angular correlation (PAC) technique and positron annihilation spectroscopy (PAS). The volume size factor of Hf in Ni was determined to be 61% by measuring the lattice parameter. The positron annihilation mean lifetime of Ni-0.5 at.%Hf after neutron irradiation at 473 K up to a dose of 0.0053 dpa was 132 ps. The lifetime decreased with increasing annealing temperature and by annealing at 723 K the recovery was finished. The PAC spectrum of 181Ta (? 181Hf) taken after the irradiation indicated that there were two components. The first component consisted of a Larmor frequency of 534 mega-radian/s (Mrad/s). The second consisted of a very broad range of frequencies which brought destructive interference among them and made the contribution to the spectrum almost zero. The component disappeared with annealing at 873 K. It was concluded that the first component and the second component represent Hf in the regular substitutional site and Hf with defect clusters, respectively. From the difference of annealing out temperature of defect clusters, clusters annihilated by 723 K were assigned as stacking fault tetrahedra (SFTs) and those by 873 K as interstitial clusters.

  17. Positron lifetime spectrometer using a DC positron beam

    DOEpatents

    Xu, Jun; Moxom, Jeremy

    2003-10-21

    An entrance grid is positioned in the incident beam path of a DC beam positron lifetime spectrometer. The electrical potential difference between the sample and the entrance grid provides simultaneous acceleration of both the primary positrons and the secondary electrons. The result is a reduction in the time spread induced by the energy distribution of the secondary electrons. In addition, the sample, sample holder, entrance grid, and entrance face of the multichannel plate electron detector assembly are made parallel to each other, and are arranged at a tilt angle to the axis of the positron beam to effectively separate the path of the secondary electrons from the path of the incident positrons.

  18. The free volume in dried and H2O-loaded biopolymers studied by positron lifetime measurements.

    PubMed

    Hugenschmidt, Christoph; Ceeh, Hubert

    2014-08-01

    We present experiments on glucose-gelatin compounds using positron annihilation lifetime spectroscopy (PALS) in order to study the behavior of the free volume dependent on H2O loading, drying, and uniaxial pressure. A semiempirical quantum mechanical model was applied in order to correlate the lifetime of orthopositronium in nanoscaled voids to the void size. This allowed us to determine the absolute value of the mean void radius in the biopolymer samples. In addition, the variation of the total free volume of the differently treated samples is quantified and illustrated by a log-normal distribution function. Most interesting results have been obtained after saturation loading with H2O that leads to the formation of voids with a mean size of 84.3(1.9) Å(3) and to an increase of the total free volume by a factor of 2.5. This observation in the swelled sample is explained by the entropy elastic regime well above the glass transition temperature that greatly facilitates the formation of free volume. Differential scanning calorimetry (DSC) measurements were performed in order to determine the glass transition temperature and to support the interpretation of the results obtained by PALS. PMID:25046083

  19. Positron lifetime studies in thermoplastic polyimide test specimens

    NASA Technical Reports Server (NTRS)

    Singh, J. J.; Stclair, T. L.; Holt, W. H.; Mock, W., Jr.

    1982-01-01

    Positron lifetime measurements were made in two thermoplastic polyimide materials recently developed at Langley. The long component lifetime values in polyimidesulfone samples are 847 + or - 81 Ps (dry) and 764 + or - 91 Ps (saturated). The corresponding values in LARC thermoplastic imides are 1080 + or - 139 Ps (dry) and 711 + or - 96 Ps (saturated). Clearly, the presence of moisture has greater effect on positron lifetime in LARC thermoplastic imides than in the case of polyimidesulfones. This result is consistent with the photomicrographic observations made on frozen water saturated specimens of these materials.

  20. Microstructural Characterization of Thin Polyimide Films by Positron Lifetime Spectroscopy

    NASA Technical Reports Server (NTRS)

    Eftekhari, A.; St.Clair, A. K.; Stoakley, D. M.; Sprinkle, Danny R.; Singh, J. J.

    1996-01-01

    Positron lifetimes have been measured in a series of thin aromatic polyimide films. No evidence of positronium formation was observed in any of the films investigated. All test films exhibited only two positron lifetime components, the longer component corresponding to the positrons annihilating at shallow traps. Based on these trapped positron lifetimes, free volume fractions have been calculated for all the films tested. A free volume model has been developed to calculate the dielectric constants of thin polyimide films. The experimental and the calculated values for the dielectric constants of the films tested are in reasonably good agreement. It has been further noted that the presence of bulky CF(sub 3) groups and meta linkages in the polyimide structure results in higher free volume fraction and, consequently, lower dielectric constant values for the films studied.

  1. Moisture dependence of positron lifetime in Kevlar-49

    NASA Technical Reports Server (NTRS)

    Singh, Jag J.; Holt, William H.; Mock, Willis, Jr.

    1984-01-01

    Because of filamentary character of Kevlar-49 aramid fibers, there is some concern about the moisture uptake and its effect on plastic composites reinforced with Kevlar-49 fibers. As part of continuing studies of positron lifetime in polymers, we have measured positron lifetime spectra in Kevlar-49 fibers as a function of their moisture content. The long lifetime component intensities are rather low, being only of the order of 2-3 percent. The measured values of long component lifetimes at various moisture levels in the specimens are as follows: 2072 +/- 173 ps (dry); 2013 +/- 193 ps (20.7 percent saturation); 1665 +/- 85 ps (25.7 percent saturation); 1745 +/- 257 ps (32.1 percent saturation); and 1772 +/- 217 ps (100 percent saturation). It is apparent that the long component lifetime at first decreases and then increases as the specimen moisture content increases. These results have been compared with those inferred from Epon-815 and Epon-815/K-49 composite data.

  2. Single shot positron annihilation lifetime spectroscopy D. B. Cassidy,a

    E-print Network

    Mills, Allen P.

    Single shot positron annihilation lifetime spectroscopy D. B. Cassidy,a S. H. M. Deng, H. K. M in positron trapping technology have made possible experimentation with dense interacting positronium gases developed a method to measure positronium lifetimes from a single intense burst of positrons. Our method

  3. Positron-Annihilation Lifetime Spectroscopy using Electron Bremsstrahlung

    NASA Astrophysics Data System (ADS)

    Wagner, A.; Anwand, W.; Butterling, M.; Cowan, T. E.; Fiedler, F.; Fritz, F.; Kempe, M.; Krause-Rehberg, R.

    2015-06-01

    A new type of an intense source of positrons for materials research has been set up at the superconducting electron linear. The source employs hard X-rays from electron- bremsstrahlung production generating energetic electron-positron pairs inside the sample under investigation. CW-operation allows performing experiments with significantly reduced pile-up artefacts in the detectors compared to pulsed mode operation in conventional accelerators. The high-resolution timing of the accelerator with bunch lengths below 10 ps full width at half maximum (FWHM) allows positron annihilation lifetime spectroscopy (PALS) measurements with high time resolution. A single-component annihilation lifetime of Kaptonhas been measured as (381.3 ± 0.3) ps. Employing segmented detectors for the detection of both annihilation photons allows for the first time to perform a 4D tomographic reconstruction of the annihilation sites including the annihilation lifetime.

  4. Microstructural Characterization of Polymers by Positron Lifetime Spectroscopy

    NASA Technical Reports Server (NTRS)

    Singh, Jag J.

    1996-01-01

    Positrons provide a versatile probe for monitoring microstructural features of molecular solids. In this paper, we report on positron lifetime measurements in two different types of polymers. The first group comprises polyacrylates processed on earth and in space. The second group includes fully-compatible and totally-incompatible Semi-Interpenetrating polymer networks of thermosetting and thermoplastic polyimides. On the basis of lifetime measurements, it is concluded that free volumes are a direct reflection of physical/electromagnetic properties of the host polymers.

  5. Slow positron beam generator for lifetime studies

    NASA Technical Reports Server (NTRS)

    Singh, Jag J. (inventor); Eftekhari, Abe (inventor); St.clair, Terry L. (inventor)

    1991-01-01

    A slow positron beam generator uses a conductive source residing between two test films. Moderator pieces are placed next to the test film on the opposite side of the conductive source. A voltage potential is applied between the moderator pieces and the conductive source. Incident energetic positrons: (1) are emitted from the conductive source; (2) are passed through test film; and (3) isotropically strike moderator pieces before diffusing out of the moderator pieces as slow positrons, respectively. The slow positrons diffusing out of moderator pieces are attracted to the conductive source which is held at an appropriate potential below the moderator pieces. The slow positrons have to pass through the test films before reaching the conductive source. A voltage is adjusted so that the potential difference between the moderator pieces and the conductive source forces the positrons to stop in the test films. Measurable annihilation radiation is emitted from the test film when positrons annihilate (combine) with electrons in the test film.

  6. Position-resolved Positron Annihilation Lifetime Spectroscopy

    NASA Astrophysics Data System (ADS)

    Wagner, A.; Butterling, M.; Fiedler, F.; Fritz, F.; Kempe, M.; Cowan, T. E.

    2013-06-01

    A new method which allows for position-resolved positron lifetime spectroscopy studies in extended volume samples is presented. In addition to the existing technique of in-situ production of positrons inside large (cm3) bulk samples using high-energy photons up to 16 MeV from bremsstrahlung production, granular position-sensitive photon detectors have been employed. A beam of intense bremsstrahlung is provided by the superconducting electron linear accelerator ELBE (Electron Linear Accelerator with high Brilliance and low Emittance) which delivers electron bunches of less than 10 ps temporal width and an adjustable bunch separation of multiples of 38 ns, average beam currents of 1 mA, and energies up to 40 MeV. Since the generation of bremsstrahlung and the transport to the sample preserves the sharp timing of the electron beam, positrons generated inside the entire sample volume by pair production feature a sharp start time stamp for positron annihilation lifetime studies with high timing resolutions and high signal to background ratios due to the coincident detection of two annihilation photons. Two commercially available detectors from a high-resolution medial positron-emission tomography system are being employed with 169 individual Lu2SiO5:Ce scintillation crystals, each. In first experiments, a positron-lifetime gated image of a planar Si/SiO2 (pieces of 12.5 mm × 25 mm size) sample and a 3-D structured metal in Teflon target could be obtained proving the feasibility of a three dimensional lifetime-gated tomographic system.

  7. M Ris-R-433 A Positron Lifetime Study of

    E-print Network

    M Risø-R-433 S A Positron Lifetime Study of Properties of Light Particles in Liquids Finn M. Jacobsen Risø National Laboratory, DK-4000 Roskilde, Denmark April 1981 #12;RISØ-R-433 A POSITRON LIFETIME. The positron lifetime technique has been used for study- ing the behaviour of the three light particles

  8. Positron and Positronium Annihilation Lifetime, and Free Volume in Polymers.

    NASA Astrophysics Data System (ADS)

    Yu, Zhibin

    1995-01-01

    Positron annihilation lifetime measurements were carried out for six polycarbonates of different structures and four polystyrenes of different molecular weight over a wide temperature range covering the glass transition region. The o-Ps mean lifetime is very sensitive to the changes of free volume in those polymers which occur due to change of molecular structure, chain length, and temperature. The influence of the unavoidable e^{+} irradiation and physical aging on the mean lifetime and the intensity of o-Ps annihilation were studied by conducting time dependent measurements on both very aged and rejuvenated samples. Both irradiation and physical aging reduce the formation of positronium, but have no effect on the mean lifetime of Ps atoms. The free volume fraction h obtained from the positron lifetime measurements was compared with the prediction of the statistical mechanical theory of Simha and Somcynsky; good agreement was found in the melt state though clear deviations were observed in the glassy state. A free volume quantity, computed from the bulk volume, which is in a good numerical agreement with the Simha-Somcynsky h-function in the melt, gives improved agreement with the h value calculated from the positron lifetime measurements. To investigate certain anomalies observed in the computer analysis of the positron annihilation lifetime spectra on polymers, we developed a computer simulation of the experimental data, which then was used to test the accuracy of the fitting results in the different circumstances. The influence caused by a possible distribution of the o-Ps mean lifetimes and the width of the spectrometer time resolution function were studied. The theoretical connection between the o-Ps mean lifetime and the free volume hole size was reviewed based on a finite spherical potential well model, and the status of the localized Ps atom in polymers was evaluated by calculation of the barrier transmission probability and the escaping probability of the trapped Ps atom. We conclude that there is no justification for a one-to-one correlation of lifetime components with specific hole sizes.

  9. Moisture determination in composite materials using positron lifetime techniques

    NASA Technical Reports Server (NTRS)

    Singh, J. J.; Holt, W. R.; Mock, W., Jr.

    1980-01-01

    A technique was developed which has the potential of providing information on the moisture content as well as its depth in the specimen. This technique was based on the dependence of positron lifetime on the moisture content of the composite specimen. The positron lifetime technique of moisture determination and the results of the initial studies are described.

  10. Positron lifetime setup based on DRS4 evaluation board

    NASA Astrophysics Data System (ADS)

    Petriska, M.; Sojak, S.; Sluge?, V.

    2014-04-01

    A digital positron lifetime setup based on DRS4 evaluation board designed at the Paul Scherrer Institute has been constructed and tested in the Positron annihilation laboratory Slovak University of Technology Bratislava. The high bandwidth, low power consumption and short readout time make DRS4 chip attractive for positron annihilation lifetime (PALS) setup, replacing traditional ADCs and TDCs. A software for PALS setup online and offline pulse analysis was developed with Qt,Qwt and ALGLIB libraries.

  11. Digitized detection of gamma-ray signals concentrated in narrow time windows for transient positron annihilation lifetime spectroscopy

    NASA Astrophysics Data System (ADS)

    Kinomura, A.; Suzuki, R.; Oshima, N.; O'Rourke, B. E.; Nishijima, T.; Ogawa, H.

    2014-12-01

    A pulsed slow-positron beam generated by an electron linear accelerator was directly used for positron annihilation lifetime spectroscopy without any positron storage devices. A waveform digitizer was introduced to simultaneously capture multiple gamma-ray signals originating from positron annihilation events during a single accelerator pulse. The positron pulse was chopped and bunched with the chopper signals also sent to the waveform digitizer. Time differences between the annihilation gamma-ray and chopper peaks were calculated and accumulated as lifetime spectra in a computer. The developed technique indicated that positron annihilation lifetime spectroscopy can be performed in a 20 ?s time window at a pulse repetition rate synchronous with the linear accelerator. Lifetime spectra of a Kapton sheet and a thermally grown SiO2 layer on Si were successfully measured. Synchronization of positron lifetime measurements with pulsed ion irradiation was demonstrated by this technique.

  12. Positron lifetime spectroscopy for investigation of thin polymer coatings

    NASA Technical Reports Server (NTRS)

    Singh, Jag J.; Sprinkle, Danny R.; Eftekhari, Abe

    1993-01-01

    In the aerospace industry, applications for polymer coatings are increasing. They are now used for thermal control on aerospace structures and for protective insulating layers on optical and microelectronic components. However, the effectiveness of polymer coatings depends strongly on their microstructure and adhesion to the substrates. Currently, no technique exists to adequately monitor the quality of these coatings. We have adapted positron lifetime spectroscopy to investigate the quality of thin coatings. Results of measurements on thin (25-micron) polyurethane coatings on aluminum and steel substrates have been compared with measurements on thicker (0.2-cm) self-standing polyurethane discs. In all cases, we find positron lifetime groups centered around 560 psec, which corresponds to the presence of 0.9-A(exp 3) free-volume cells. However, the number of these free-volume cells in thin coatings is larger than in thick discs. This suggests that some of these cells may be located in the interfacial regions between the coatings and the substrates. These results and their structural implications are discussed in this report.

  13. Neutron Lifetime Measurements

    SciTech Connect

    Nico, J. S. [National Institute of Standards and Technology, Physics Laboratory, Gaithersburg, MD 20899 (United States)

    2006-11-17

    Precision measurements of neutron beta decay address basic questions in nuclear and particle physics, astrophysics, and cosmology. As the simplest semileptonic decay system, the free neutron plays an important role in understanding the physics of the weak interaction, and improving the precision of the neutron lifetime is fundamental to testing the validity of the theory. The neutron lifetime also directly affects the relative abundance of primordial helium in big bang nucleosynthesis. There are two distinct strategies for measuring the lifetime. Experiments using cold neutrons measure the absolute specific activity of a beam of neutrons by counting decay protons; experiments using confined, ultracold neutrons determine the lifetime by counting neutrons that remain after some elapsed time. The status of the recent lifetime measurements using both of these techniques is discussed.

  14. A modified positron lifetime spectrometer as method of non-destructive testing in materials

    NASA Astrophysics Data System (ADS)

    Chen, Z. Q.; Shi, J. J.; Jiang, J.; Liu, X. B.; Wang, R. S.; Wu, Y. C.

    2015-02-01

    This paper aims to develop a new non-destructive testing (NDT) method using positron annihilation spectroscopy, a powerful tool to detect vacancy-type defects and defect's chemical environment. A positron NDT system was designed and constructed by modifying the "sandwich" structure of sample-source-sample in the conventional positron lifetime spectrometer. The positron lifetime spectra of one single sample can be measured and analyzed by subtracting the contribution of a reference sample. The feasibility and reliability of the positron NDT system have been tested by analyzing nondestructively deformation damage caused by mechanical treatment in metals and steels. This system can be used for detecting defects and damage in thick or large-size samples without cutting off the sample materials, as well as for detecting two-dimensional distribution of defects.

  15. Materials characterization of free volume and void properties by two-dimensional positron annihilation lifetime spectroscopy

    NASA Astrophysics Data System (ADS)

    Chen, Hongmin; Van Horn, J. David; Jean, Y. C.; Hung, Wei-Song; Lee, Kueir-Rarn

    2013-04-01

    Positron annihilation lifetime spectroscopy (PALS) has been widely used to determine the free volume and void properties in polymeric materials. Recently, a two dimensional positron annihilation lifetime spectroscopy (2DPALS) system has been developed for membrane applications. The system measures the coincident signals between the lifetime and the energy which could separate the 2? and 3? annihilations and improve the accuracy in the determination of the free volume and void properties. When 2D-PALS is used in coupling with a variable mono-energy slow positron beam, it could be applied to a variety of material characterization. Results of free volumes and voids properties in a multi-layer polymer membrane characterized using 2D-PALS are presented.

  16. Coupled experimental and DFT +U investigation of positron lifetimes in UO2

    NASA Astrophysics Data System (ADS)

    Wiktor, Julia; Barthe, Marie-France; Jomard, Gérald; Torrent, Marc; Freyss, Michel; Bertolus, Marjorie

    2014-11-01

    We performed positron annihilation spectroscopy measurements on uranium dioxide irradiated with 45 MeV ? particles. The positron lifetime was measured as a function of the temperature in the 15-300 K range. The experimental results were combined with electronic structure calculations of positron lifetimes of vacancies and vacancy clusters in UO2. Neutral and charged defects consisting of from one to six vacancies were studied computationally using the DFT +U method to take into account strong correlations between the 5 f electrons of uranium. The two-component density functional theory with two different fully self-consistent schemes was used to calculate the positron lifetimes. All defects were relaxed taking into account the forces due to the creation of defects and the positron localized in the vacancy. The interpretation of the experimental observations in the light of the DFT + U results and the positron trapping model indicates that neutral VU+2 VO trivacancies (bound Schottky defects) are the predominant defects detected in the 45 MeV ? irradiated UO2 samples. Our results show that the coupling of a precise experimental work and calculations using carefully chosen assumptions is an effective method to bring further insight into the subject of irradiation induced defects in UO2.

  17. Cosmic-Ray Positron Measurements

    NASA Astrophysics Data System (ADS)

    Schubnell, Michael

    Direct measurements of cosmic-ray electrons and positrons were first made in the early 1960s and since then a number of instruments were built to study this component of the cosmic radiation. The precise measurement of the intensities of CR electrons and positrons are key to our understanding of cosmic-ray origin and propagation. In addition the locally observed abundance of cosmic ray electrons and/or positrons may exhibit interesting spectral features. Observations confirm the almost exclusive secondary nature of positrons up to a few GeV but measurements by the HEAT-e instrument suggested as early as 1995 a possible primary positron component. More recent reports by the PAMELA team of a continued rise in the cosmic-ray positron fraction above about 10 GeV and of an excess of cosmic-ray electrons around a few hundred GeV by the ATIC collaboration have resulted in a flurry of publications interpreting these observations either as a possible dark matter signature or as a contribution from isolated astrophysical sources. While those interpretations are scientically exciting, the possibility that measurements are contaminated by misidentied cosmic-ray protons cannot be ignored. I will present a new analysis of low energy positron data taking into account modulation effects due to the solar cycle and I will take a critical look at current positron measurements and discuss theoretical interpretations from an experimentalist's point of view.

  18. Portable Positron Measurement System (PPMS)

    SciTech Connect

    None

    2011-01-01

    Portable Positron Measurement System (PPMS) is an automated, non-destructive inspection system based on positron annihilation, which characterizes a material's in situatomic-level properties during the manufacturing processes of formation, solidification, and heat treatment. Simultaneous manufacturing and quality monitoring now are possible. Learn more about the lab's project on our facebook site http://www.facebook.com/idahonationallaboratory.

  19. Study of Chemical Carcinogens by Positron Annihilation Lifetime Spectroscopy

    NASA Astrophysics Data System (ADS)

    Pivtsaev, A. A.; Razov, V. I.; Karasev, A. O.

    2013-11-01

    We have used positron annihilation lifetime spectroscopy to study the carcinogens C21H20BrN3, C4H7Cl2O4P, CCl4, CHCl3, AlF3, C8H12N4O, C6H4Cl2 and the non-carcinogens H2O, AlCl3, CH2Cl2, C2H6OS. We have established a correlation between the annihilation characteristics of the studied compounds and their degree of carcinogenicity.

  20. Positron lifetime spectroscopic studies of nanocrystalline ZnFe2O4

    NASA Astrophysics Data System (ADS)

    Nambissan, P. M. G.; Upadhyay, C.; Verma, H. C.

    2003-05-01

    By carrying out positron lifetime measurements in zinc ferrite (ZnFe2O4) samples of various grain sizes down to 5 nm, the defect microstructures have been identified. In the bulk samples composed of grains of large sizes, positrons were trapped by monovacancies in the crystalline structure. Upon reduction of the grain sizes to nanometer dimensions, positrons get trapped selectively at either the diffused vacancies on the grain surfaces and the intergranular regions. Below about 9 nm, the grains undergo the transformation from the normal spinel structure to the inverse phase. A concomitant lattice contraction results in substantial reduction of the octahedral site volume, and hence, a fraction of the Zn2+ ions with larger ionic radius fails to occupy these sites. This leaves vacancies at the octahedral sites which then turn out to be the major trapping sites for positrons. ZnFe2O4 samples prepared through different routes were investigated, which showed similar qualitative features, although those synthesized through the hydrothermal precipitation method showed remarkably larger lifetimes for trapped positrons upon nanocrystallization in comparison to the samples prepared through the citrate route.

  1. Positron lifetime studies of decomposition in 2024 (Al-Cu-Mg) and 7010 (Al-Zn-Cu-Mg) alloys

    SciTech Connect

    Dlubek, G. [ITA Inst. fuer Innovative Technologien GmbH, Halle (Germany)] [ITA Inst. fuer Innovative Technologien GmbH, Halle (Germany); [Martin-Luther-Univ. Halle-Wittenberg, Halle (Germany). Fachbereich Physik; Lademann, P.; Krause, H.; Krause, S.; Unger, R. [Martin-Luther-Univ. Halle-Wittenberg, Halle (Germany). Fachbereich Physik] [Martin-Luther-Univ. Halle-Wittenberg, Halle (Germany). Fachbereich Physik

    1998-09-04

    In the current paper, the decomposition behavior of the engineering alloys 2024 (Al-Cu-Mg) and 7010 (Al-Zn-Cu-Mg) is studied using positron lifetime measurements. Positrons probe open volume defects such as vacancies and dislocations. However, they may also be used to investigate coherent zones and incoherent precipitates. In order to understand the rather complicated precipitation sequences and the response of positrons to different type of precipitates occurring in 2024 and 7010 alloys, binary and ternary laboratory alloys were also investigated under the same experimental conditions as the engineering alloys. The interpretations of the results are based on experiences of the group from extensive positron studies of laboratory alloys such as Al-Zn, Al-Zn-Mg, Al-Cu, and further Al alloys (see also the review (4)). Their collected results are shown as lifetimes and curve-shape parameters S of the electron-positron momentum distribution curves characteristic for different precipitates in Al alloys.

  2. Measurement of charm meson lifetimes

    E-print Network

    Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Davis, Robin E. P.; Kravchenko, I.; Kwak, Nowhan; Zhao, L.

    1999-06-01

    We report measurements of the D-0, D-,(+) and D-s(+) meson lifetimes using 3.7 fb(-1) of e(+)e(-) annihilation data collected near the Y(4S) resonance with the CLEO detector. The measured lifetimes of the D-0, D+, and ...

  3. Measurement of the ?c+ lifetime

    Microsoft Academic Search

    A. Mahmood; S. Csorna; I. Danko; Z. Xu; G. Bonvicini; D. Cinabro; M. Dubrovin; S. McGee; A. Bornheim; E. Lipeles; S. Pappas; A. Shapiro; W. Sun; A. Weinstein; G. Masek; H. Paar; R. Mahapatra; R. Morrison; H. Nelson; R. Briere; G. Chen; T. Ferguson; G. Tatishvili; H. Vogel; N. Adam; J. Alexander; C. Bebek; K. Berkelman; F. Blanc; V. Boisvert; D. Cassel; P. Drell; J. Duboscq; K. Ecklund; R. Ehrlich; R. Galik; L. Gibbons; B. Gittelman; S. Gray; D. Hartill; B. Heltsley; L. Hsu; C. Jones; J. Kandaswamy; D. Kreinick; A. Magerkurth; H. Mahlke-Krüger; T. Meyer; N. Mistry; E. Nordberg; M. Palmer; J. Patterson; D. Peterson; J. Pivarski; D. Riley; A. Sadoff; H. Schwarthoff; M. Shepherd; J. Thayer; D. Urner; B. Valant-Spaight; G. Viehhauser; A. Warburton; M. Weinberger; S. Athar; P. Avery; C. Prescott; H. Stoeck; J. Yelton; G. Brandenburg; A. Ershov; D. Kim; R. Wilson; K. Benslama; B. Eisenstein; J. Ernst; G. Gollin; R. Hans; I. Karliner; N. Lowrey; M. Marsh; C. Plager; C. Sedlack; M. Selen; J. Thaler; J. Williams; K. Edwards; R. Ammar; D. Besson; X. Zhao; S. Anderson; V. Frolov; Y. Kubota; S. Lee; S. Li; R. Poling; A. Smith; C. Stepaniak; J. Urheim; S. Ahmed; M. Alam; L. Jian; M. Saleem; F. Wappler; E. Eckhart; K. Gan; C. Gwon; T. Hart; K. Honscheid; D. Hufnagel; H. Kagan; R. Kass; T. Pedlar; E. von Toerne; T. Wilksen; M. Zoeller; S. Richichi; H. Severini; P. Skubic; S. Dytman; S. Nam; V. Savinov; S. Chen; J. Hinson; J. Lee; D. Miller; V. Pavlunin; E. Shibata; I. Shipsey; D. Cronin-Hennessy; A. Lyon; E. Thorndike; T. Coan; Y. Gao; F. Liu; Y. Maravin; I. Narsky; R. Stroynowski; J. Ye; M. Artuso; C. Boulahouache; K. Bukin; E. Dambasuren; T. Skwarnicki; S. Stone; J. Wang

    2001-01-01

    The Xi^+_c lifetime is measured using 9.0 fb^-1 of e+e- annihilation data\\u000acollected on and just below the Upsilon(4S) resonance with the CLEO II.V\\u000adetector at CESR. This is the first measurement of the Xi^+_c lifetime from a\\u000acollider experiment. Using an unbinned maximum likelihood fit, the Xi^+_c\\u000alifetime is measured to be 503 +\\/- 47 (stat.) +\\/- 18 (syst.)

  4. Measurement of the tau lifetime

    SciTech Connect

    Jaros, J.A.

    1982-10-01

    If the tau lepton couples to the charged weak current with universal strength, its lifetime can be expressed in terms of the muon's lifetime, the ratio of the masses of the muon and the tau, and the tau's branching ratio into e anti nu/sub e/ nu/sub tau/ as tau/sub tau/ = tau/sub ..mu../ (m/sub ..mu..//m/sub tau/)/sup 5/ B(tau ..-->.. e anti nu/sub e/nu/sub tau/) = 2.8 +- 0.2 x 10/sup -13/ s. This paper describes the measurement of the tau lifetime made by the Mark II collaboration, using a new high precision drift chamber in contunction with the Mark II detector at PEP. The results of other tau lifetime measurements are summarized.

  5. Investigation of free volume changes in the structure of the polymer bifocal contact lenses using positron lifetime spectroscopy PALS.

    PubMed

    Filipecki, Jacek; Kocela, Agnieszka; Korzekwa, Piotr; Filipecka, Katarzyna; Golis, Edmund; Korzekwa, Witold

    2011-01-01

    Positron annihilation lifetime spectroscopy PALS has been applied of free volume properties in bifocal contact lenses. The measurements have been made on new lenses and then after one, two, three and four weeks wear. The longest lifetime, obtained via three-component analyses of the spectra, was associated with the pick-off annihilation of ortho-positronium trapped in the free volume. After wear of the lenses changes in the ortho-positronium lifetimes and the relative intensity of the longest component were observed. These results are discussed on the basis of a free volume model. PMID:21866793

  6. Z .Applied Surface Science 149 1999 97102 Unfolding positron lifetime spectra with neural networks

    E-print Network

    Pázsit, Imre

    Z .Applied Surface Science 149 1999 97­102 Unfolding positron lifetime spectra with neural networks is based on the use of artificial neural networks ANNs . By using data from simulated positron spectra: Artificial neural networks ANNs ; Amplitudes; Simulation model 1. Introduction Determination of mean

  7. Development of a compact and fast response detector using an Yb:Lu2O3 scintillator for lifetime sensitive positron emission tomography

    NASA Astrophysics Data System (ADS)

    Taira, Y.; Kuroda, R.; Tanaka, M.; Oshima, N.; O'Rourke, B. E.; Suzuki, R.; Toyokawa, H.; Watanabe, K.; Yanagida, T.; Yagi, H.; Yanagitani, T.

    2014-05-01

    We propose a method for obtaining three-dimensional imaging measurements of the defect distribution inside industrial materials by measuring positron lifetimes, in addition to using the imaging technique of positron emission tomography. A compact and fast response detector that uses an Yb3+-doped Lu2O3 scintillator and a photomultiplier tube was developed and tested. Yb3+ charge transfer luminescence exhibits a fast response in the ultraviolet and visible regions. The first measurement of the positron lifetime for a bulk material using an Yb:Lu2O3 scintillator was carried out. The lifetime of positrons created inside an yttria-stabilized zirconia block via pair production produced by ultrashort photon pulses was successfully measured.

  8. Analytical evidence for quantum states in aqueous vanadium pentoxide with positron lifetime spectroscopy

    E-print Network

    L. V. Elnikova

    2010-04-26

    The possibility of registration of quantum states, such as the coalescence of droplets (tactoids) in the sol phase of aqueous vanadium pentoxide V$_2$O$_5$, with positron annihilation lifetime spectroscopy is discussed. The decrease of the long-living positronium (Ps) lifetime term in the result of the coalescence of V$_2$O$_5$ tactoids is predicted.

  9. Microstructural Characterization of Semi-Interpenetrating Polymer Networks by Positron Lifetime Spectroscopy

    NASA Technical Reports Server (NTRS)

    Singh, Jag J.; Pater, Ruth H.; Eftekhari, Abe

    1996-01-01

    Thermoset and thermoplastic polyimides have complementary physical and mechanical properties. Whereas thermoset polyimides are brittle and generally easier to process, thermoplastic polyimides are tough but harder to process. A combination of these two types of polyimides may help produce polymers more suitable for aerospace applications. Semi-Interpenetrating Polymer Networks (S-IPN) of thermoset LaRC(TM)-RP46 and thermoplastic LaRC(TM)-IA polyimides were prepared in weight percent ratios ranging from 100:0 to 0:100. Positron lifetime measurements were made in these samples to correlate their free volume features with physical and mechanical properties. As expected, positronium atoms are not formed in these samples. The second lifetime component has been used to infer the positron trap dimensions. The 'free volume' goes through a minimum at a ratio of about 50:50, and this suggests that S-IPN samples are not merely solid solutions of the two polymers. These data and related structural properties of the S-IPN samples are discussed.

  10. Low energy positron flux generator for lifetime studies in thin films

    NASA Technical Reports Server (NTRS)

    Singh, Jag J.; St. Clair, Terry L.; Eftekhari, Abe

    1991-01-01

    A slow positron flux generator for positron annihilation spectroscopic measurements in thin polymer films is described. The advantages of this generator include operability at room temperature and atmospheric pressure without special test film preparaton requirements.

  11. Characterization of interfaces in Binary and Ternary Polymer Blends by Positron Lifetime Spectroscopy

    NASA Astrophysics Data System (ADS)

    Ranganathaiah, C.

    2015-06-01

    A miscible blend is a single-phase system with compact packing of the polymeric chains/segments due configuration/conformational changes upon blending. Differential Scanning Calorimetry (DSC) is the most employed method to ascertain whether the blend is miscible or immiscible. Positron Lifetime Spectroscopy (PLS) has been employed in recent times to study miscibility properties of polymer blends by monitoring the ortho-Positronium annihilation lifetimes as function of composition. However, just free volume monitoring and the DSC methods fail to provide the composition dependent miscibility of blends. To overcome this limitation, an alternative approach based on hydrodynamic interactions has been developed to derive this information using the same o-Ps lifetime measurements. This has led to the development of a new method of measuring composition dependent miscibility level in binary and ternary polymer blends. Further, the new method also provides interface characteristics for immiscible blends. The interactions between the blend components has a direct bearing on the strength of adhesion at the interface and hence the hydrodynamic interaction. Understanding the characteristic of interfaces which decides the miscibility level of the blend and their end applications is made easy by the present method. The efficacy of the present method is demonstrated for few binary and ternary blends.

  12. A slow positron beam generator for lifetime studies

    NASA Astrophysics Data System (ADS)

    Singh, Jag J.; Eftekhari, Abe; St. Clair, Terry L.

    1989-04-01

    A slow positron beam generator using well-annealed polycrystalline tungsten moderators and a Na-22 positron source was developed. A 250 micro c source, deposited on a 2.54 micron thick aluminized mylar, is sandwiched between two (2.54 cm x 2.54 cm x 0.0127 cm) tungsten pieces. Two (2.54 cm x 2.54 cm x t cm) test polymer films insulate the two tungsten moderator pieces from the aluminized mylar source holder (t=0.00127 to 0.0127). A potential difference of 10 to 100 volts--depending on the test polymer film thickness (t)--is applied between the tungsten pieces and the source foil. Thermalized positrons diffusing out of the moderator pieces are attracted to the source foil held at an appropriate potential below the moderator pieces. These positrons have to pass through the test polymer films before they can reach the source foil. The potential difference between the moderator pieces and the aluminized mylar is so adjusted as to force the positrons to stop in the test polymer films. Thus the new generator becomes an effective source of positrons for assaying thin polymer films for their molecular morphology.

  13. PALSfit: A computer program for analysing positron lifetime spectra

    E-print Network

    , Morten Eldrup, and Niels Jørgen Pedersen Risø-R-1652(EN) Risø National Laboratory for Sustainable Energy: 43 Information Service Department Risø National Laboratory for Sustainable Energy Technical) February 2009 Abstract: A Windows based computer program PALSfit has been developed for analysing positron

  14. Study of bicontinuous phase in (TTAB+pentanol)/water/n-octane reverse micellar system using positron lifetime spectroscopy

    NASA Astrophysics Data System (ADS)

    Chandramani Singh, K.; Yadav, R.; Khani, P. H.

    2013-06-01

    A phase diagram of (TTAB+pentanol)/water/n-octane has been mapped by using optical method. It exhibits a reverse micellar (L2) phase extending over a wide range of concentrations of the constituents. To investigate the fine structure of the L2 phase, a series of (TTAB+pentanol)/n-octane ternary mixtures having initial concentrations of (TTAB+pentanol) (1:1) in n-octane as 35%, 50% and 65% by weight were prepared. In each of these mixtures, positron lifetime measurements were performed as a function of the concentration of water, using a standard lifetime spectrometer. At water concentrations of 11.8%, 8.5% and 8.4% by weight respectively for the above systems, the o-Ps pick-off lifetime ?3 shows an oscillatory behaviour while I3 representing the Ps formation exhibits an abrupt change. These changes in the positron annihilation parameters have been explained on the basis of onset of bicontinuity in the microemulsion phase. The positron annihilation technique thus suggests the existence of droplet-like and bicontinuous structures in the L2 phase which is otherwise considered optically to be a single phase as the system remains clear and isotropic throughout this phase. Supporting evidence has been provided by the electrical conductivity measurements performed in these systems. These results are presented in this paper.

  15. Lifetime measurements for bottom hadrons

    SciTech Connect

    Wolf, G.

    1984-09-01

    The review of lifetime measurements of bottom hadrons begins with a first measurement by JADE, followed by similar measurements by MAC and MKII groups. New MAC data are reviewed based on a total of 75,000 multihadron events taken at a c.m. energy of 29 GeV. According to Monte Carlo calculations, 18% of the lepton candidates stem from charm decay and roughly 30% were misidentified hadrons. DELCO studied electrons obtained from 42,000 multihadron events at 29 GeV. The electrons were identified by means of Cerenkov counters. JADE analayzed 22,000 multihadron events at 35 GeV. Data were analyzed using two methods - one using a sample of b-enriched events, and the other using weighted distributions. The TASSO results were obtained with two different configurations of the detector - one of which used a drift chamber and the other a vertex detector. (LEW)

  16. Lifetime measurements in highly ionized silicon

    NASA Astrophysics Data System (ADS)

    Livingston, A. E.; Serpa, F. G.; Zacarias, A. S.; Curtis, L. J.; Berry, H. G.; Blundell, S. A.

    1991-12-01

    We report the measurement of excited-state lifetimes in highly ionized silicon atoms using multiplexed detection of a fast-ion beam source. Simultaneous lifetime measurements for resonance transitions and for Rydberg transitions in Si xi and Si xii have been performed. Comparisons with theoretical lifetimes are presented, and good agreement is obtained with a new relativistic many-body calculation of the 2p fine-structure-state lifetimes in lithium-like Si xii.

  17. Measurement of the ?-lepton lifetime at Belle

    SciTech Connect

    Belous, K.; Shapkin, M.; Sokolov, A.; Adachi, I.; Aihara, H.; Asner, David M.; Aulchenko, V.; Bakich, A. M.; Bala, Anu; Bhuyan, Bipul; Bobrov, A.; Bondar, A.; Bonvicini, Giovanni; Bozek, A.; Bracko, Marko; Browder, Thomas E.; Cervenkov, D.; Chekelian, V.; Chen, A.; Cheon, B. G.; Chilikin, K.; Chistov, R.; Cho, K.; Chobanova, V.; Choi, Y.; Cinabro, David A.; Dalseno, J.; Dolezal, Z.; Dutta, Deepanwita; Eidelman, S.; Epifanov, D.; Farhat, H.; Fast, James E.; Ferber, T.; Gaur, Vipin; Ganguly, Sudeshna; Garmash, A.; Gillard, R.; Goh, Y. M.; Golob, B.; Haba, J.; Hara, Takanori; Hayasaka, K.; Hayashii, H.; Hoshi, Y.; Hou, W. S.; Iijima, T.; Inami, K.; Ishikawa, A.; Itoh, R.; Iwashita, T.; Jaegle, Igal; Julius, T.; Kato, E.; Kichimi, H.; Kiesling, C.; Kim, D. Y.; Kim, H. J.; Kim, J. B.; Kim, M. J.; Kim, Y. J.; Kinoshita, Kay; Ko, Byeong Rok; Kodys, P.; Korpar, S.; Krizan, Jean; Krokovny, Pavel; Kuhr, T.; Kuzmin, A.; Kwon, Y. J.; Lange, J. S.; Lee, S. H.; Libby, J.; Liventsev, Dmitri; Lukin, P.; Matvienko, D.; Miyata, H.; Mizuk, R.; Mohanty, G. B.; Mori, T.; Mussa, R.; Nagasaka, Y.; Nakano, E.; Nakao, M.; Nayak, Minakshi; Nedelkovska, E.; Ng, C.; Nisar, N. K.; Nishida, S.; Nitoh, O.; Ogawa, S.; Okuno, S.; Olsen, Stephen L.; Ostrowicz, W.; Pakhlova, Galina; Park, C. W.; Park, H.; Park, H. K.; Pedlar, Todd; Pestotnik, Rok; Petric, Marko; Piilonen, Leo E.; Ritter, M.; Rohrken, M.; Rostomyan, A.; Ryu, S.; Sahoo, Himansu B.; Saito, Tomoyuki; Sakai, Yoshihide; Sandilya, Saurabh; Santel, Daniel; Santelj, Luka; Sanuki, T.; Savinov, Vladimir; Schneider, O.; Schnell, G.; Schwanda, C.; Semmler, D.; Senyo, K.; Seon, O.; Shebalin, V.; Shen, C. P.; Shibata, T. A.; Shiu, Jing-Ge; Shwartz, B.; Sibidanov, A.; Simon, F.; Sohn, Young-Soo; Stanic, S.; Stanic, M.; Steder, M.; Sumiyoshi, T.; Tamponi, Umberto; Tatishvili, Gocha; Teramoto, Y.; Trabelsi, K.; Tsuboyama, T.; Uchida, M.; Uehara, S.; Uglov, T.; Unno, Yuji; Uno, S.; Usov, Y.; Vahsen, Sven E.; Van Hulse, C.; Vanhoefer, P.; Varner, Gary; Varvell, K. E.; Vinokurova, A.; Vorobyev, V.; Wagner, M. N.; Wang, C. H.; Wang, P.; Watanabe, M.; Watanabe, Y.; Williams, K. M.; Won, E.; Yamaoka, J.; Yamashita, Y.; Yashchenko, S.; Yook, Youngmin; Yuan, C. Z.; Zhang, Z. P.; Zhilich, V.; Zupanc, A.

    2014-01-23

    The lifetime of the Tau-lepton is measured using the process , where both leptons decay to . The result for the mean lifetime, based on of data collected with the Belle detector at the resonance and below, is . The first measurement of the lifetime difference between and is performed. The upper limit on the relative lifetime difference between positive and negative leptons is at 90% C.L. (That would make sense if ERICA could take RTF....)

  18. Fluorescence lifetime measurement from a designated single-bunch in the BEPC II colliding mode

    Microsoft Academic Search

    Shuai-Shuai Sun; Guang-Lei Xu; Ge Lei; Yan Huang; Zhen-Hua Gao; Zhi-Yin Zhang; Ye Tao

    2011-01-01

    Fluorescence lifetime measurement in the time domain requires excitation from a well separated single bunch using synchrotron light sources. In the colliding mode of the Beijing Electron Positron Collider II (BEPCII), a hybrid filling pattern was realized such that a single bunch was placed in the middle of a large gap between two multi-bunch groups. Detection of fluorescence lifetime, based

  19. Emittance measurement of laser produced positrons

    NASA Astrophysics Data System (ADS)

    Chen, Hui; Sheppard, J.; Gronberg, J.; Wilks, S.; Anderson, S.; Hazi, A.; Kerr, S.; Marley, E.; Park, J.; Tommasini, R.

    2011-10-01

    Intense lasers have been shown to produce a large number (~1010) of quasi monoenergetic positrons in a short (ps) burst. This suggests the possibility of using laser-generated positrons as injector sources for high-energy accelerators. One of the key parameters for evaluating this application is the positron beam emittance, a measure of the beam size and divergence. We performed a series of measurements on the Titan laser at Lawrence Livermore National Laboratory for this purpose. 1-D Pepper-pot, a standard technique, was used for a number of laser and target conditions. The emittance was also calculated using the Electron-Gamma-Shower (EGS4) code. This talk will present the experimental and simulation results, and their implication for this positron source for accelerators. This work performed under the auspices of the U.S. DOE by LLNL under Contract DE-AC52-07NA27344 and was funded by LDRD #10-ERD-044.

  20. RDDS lifetime measurement with JUROGAM + RITU

    NASA Astrophysics Data System (ADS)

    Grahn, T.; Dewald, A.; Möller, O.; Beausang, C. W.; Eeckhaudt, S.; Greenlees, P. T.; Jolie, J.; Jones, P.; Julin, R.; Juutinen, S.; Kettunen, H.; Kröll, T.; Krücken, R.; Leino, M.; Leppänen, A.-P.; Maierbeck, P.; Meyer, D. A.; Nieminen, P.; Nyman, M.; Pakarinen, J.; Petkov, P.; Rahkila, P.; Saha, B.; Scholey, C.; Uusitalo, J.

    2005-09-01

    Lifetimes in 188Pb were measured using the Köln plunger in combination with the RITU separator and JUROGAM. Four lifetimes were measured, from which the deformation of the prolate band was experimentally determined for the first time. The squared prolate mixing amplitude of the 21+ state was deduced from the measured B(E2) values.

  1. Variation of free volume size and content of shape memory polymer — Polyurethane — Upon temperature studied by positron annihilation lifetime techniques and infrared spectroscopy

    Microsoft Academic Search

    K. Ito; K. Abe; H. L. Li; Y. Ujihira; N. Ishikawa; S. Hayashi

    1996-01-01

    Positron annihilation lifetime measurement and Fourier transform infrared spectrometry were applied to the study of temperature dependencies of free volume parameters and hydrogen bonds in segmented polyurethane, specially fabricated as a shape memory polymer. The variation of free volumes in amorphous region were correlated to that of hydrogen bonding and the shape memory mechanism of polyurethane is elucidated from a

  2. Positron Annihilation Lifetime Study of Steel Surface Modification by Shot Peening

    NASA Astrophysics Data System (ADS)

    Zaleski, Rados?aw; Gorgol, Marek; Zaleski, Kazimierz

    Steel made machine components are often exposed to variable loads during the operation. Thus, their important characteristic is fatigue strength, which largely depends on the residual stress in the surface layer of these elements. The fatigue strength of components can be increased e.g. by exposing them to shot peening. Influence of shot peening on the defect structure in the samples observed by positron annihilation lifetime spectroscopy was studied for various steels. The differences between unprocessed and shot peened samples reflect mostly in the intensity ratio decrease of the components attributed to monovacancies and vacancy clusters. Shot peening result in uniformization of the vacancy clusters size. The carburized steel does not exhibit any changes in positron annihilation lifetime spectra caused by shot peening. On the other hand, the changes in the chromium plated steel are considerable. Their origin lies is compression of the microcracks present in the chromium layer caused by shot peening.

  3. Recent measurements of the B hadron lifetime

    SciTech Connect

    Ong, R.A.

    1987-12-01

    Recent measurements of the B hadron lifetime from PEP and PETRA experiments are presented. These measurements firmly establish that the B lifetime is long (approx.1 psec), implying that the mixing between the third generation of quarks and the lighter quarks is much weaker that the mixing between the first two generations.

  4. Measurement of the ?-lepton lifetime at Belle.

    PubMed

    Belous, K; Shapkin, M; Sokolov, A; Adachi, I; Aihara, H; Asner, D M; Aulchenko, V; Bakich, A M; Bala, A; Bhuyan, B; Bobrov, A; Bondar, A; Bonvicini, G; Bozek, A; Bra?ko, M; Browder, T E; ?ervenkov, D; Chekelian, V; Chen, A; Cheon, B G; Chilikin, K; Chistov, R; Cho, K; Chobanova, V; Choi, Y; Cinabro, D; Dalseno, J; Doležal, Z; Dutta, D; Eidelman, S; Epifanov, D; Farhat, H; Fast, J E; Ferber, T; Gaur, V; Ganguly, S; Garmash, A; Gillard, R; Goh, Y M; Golob, B; Haba, J; Hara, T; Hayasaka, K; Hayashii, H; Hoshi, Y; Hou, W-S; Iijima, T; Inami, K; Ishikawa, A; Itoh, R; Iwashita, T; Jaegle, I; Julius, T; Kato, E; Kichimi, H; Kiesling, C; Kim, D Y; Kim, H J; Kim, J B; Kim, M J; Kim, Y J; Kinoshita, K; Ko, B R; Kodyš, P; Korpar, S; Križan, P; Krokovny, P; Kuhr, T; Kuzmin, A; Kwon, Y-J; Lange, J S; Lee, S-H; Libby, J; Liventsev, D; Lukin, P; Matvienko, D; Miyata, H; Mizuk, R; Mohanty, G B; Mori, T; Mussa, R; Nagasaka, Y; Nakano, E; Nakao, M; Nayak, M; Nedelkovska, E; Ng, C; Nisar, N K; Nishida, S; Nitoh, O; Ogawa, S; Okuno, S; Olsen, S L; Ostrowicz, W; Pakhlova, G; Park, C W; Park, H; Park, H K; Pedlar, T K; Pestotnik, R; Petri?, M; Piilonen, L E; Ritter, M; Röhrken, M; Rostomyan, A; Ryu, S; Sahoo, H; Saito, T; Sakai, Y; Sandilya, S; Santel, D; Santelj, L; Sanuki, T; Savinov, V; Schneider, O; Schnell, G; Schwanda, C; Semmler, D; Senyo, K; Seon, O; Shebalin, V; Shen, C P; Shibata, T-A; Shiu, J-G; Shwartz, B; Sibidanov, A; Simon, F; Sohn, Y-S; Stani?, S; Stari?, M; Steder, M; Sumiyoshi, T; Tamponi, U; Tatishvili, G; Teramoto, Y; Trabelsi, K; Tsuboyama, T; Uchida, M; Uehara, S; Uglov, T; Unno, Y; Uno, S; Usov, Y; Vahsen, S E; Van Hulse, C; Vanhoefer, P; Varner, G; Varvell, K E; Vinokurova, A; Vorobyev, V; Wagner, M N; Wang, C H; Wang, P; Watanabe, M; Watanabe, Y; Williams, K M; Won, E; Yamaoka, J; Yamashita, Y; Yashchenko, S; Yook, Y; Yuan, C Z; Zhang, Z P; Zhilich, V; Zupanc, A

    2014-01-24

    The lifetime of the ? lepton is measured using the process e+ e- ? ?+ ?- , where both ? leptons decay to 3??(?). The result for the mean lifetime, based on 711??fb(-1) of data collected with the Belle detector at the ?(4S) resonance and 60??MeV below, is ?=(290.17±0.53(stat)±0.33(syst))×10(-15)??s. The first measurement of the lifetime difference between ?+ and ?- is performed. The upper limit on the relative lifetime difference between positive and negative ? leptons is |??|/?<7.0×10(-3) at 90% C.L. PMID:24484129

  5. Proposed Parameter-Free Model for Interpreting the Measured Positron Annihilation Spectra of Materials Using a Generalized Gradient Approximation

    NASA Astrophysics Data System (ADS)

    Barbiellini, Bernardo; Kuriplach, Jan

    2015-04-01

    Positron annihilation spectroscopy is often used to analyze the local electronic structure of materials of technological interest. Reliable theoretical tools are crucial to interpret the measured spectra. Here, we propose a parameter-free gradient correction scheme for a local-density approximation obtained from high-quality quantum Monte Carlo data. The results of our calculations compare favorably with positron affinity and lifetime measurements, opening new avenues for highly precise and advanced positron characterization of materials.

  6. Defects in electron-irradiated GaAs studied by positron lifetime spectroscopy

    SciTech Connect

    Polity, A.; Rudolf, F.; Nagel, C.; Eichler, S.; Krause-Rehberg, R. [Fachbereich Physik der Martin-Luther-Universitaet Halle-Wittenberg, Experimentelle Physik III, Friedemann-Bach-Platz 6, D-06108 Halle/Saale (Germany)] [Fachbereich Physik der Martin-Luther-Universitaet Halle-Wittenberg, Experimentelle Physik III, Friedemann-Bach-Platz 6, D-06108 Halle/Saale (Germany)

    1997-04-01

    A systematic study of electron-irradiation-induced defects in GaAs was carried out. The irradiation was performed at low temperature (4 K) with an incident energy of 2 MeV. Both, the defect formation and annealing behavior were studied in dependence on the fluence (10{sup 15}--10{sup 19} cm{sup {minus}2}) in undoped, n-, and p-doped GaAs. Temperature-dependent positron lifetime measurements were performed between 20 and 600 K. The thermal stability of defects was studied by annealing experiments in the temperature range of 90--600 K. A defect complex, which anneals in a main stage at 300 K, was found in all GaAs samples after electron irradiation. A possible candidate for this defect is a complex of a vacancy connected with an intrinsic defect. A second vancancylike defect was observed in n-type material after annealing at 550 K. This defect was assumed to be in the As sublattice. {copyright} {ital 1997} {ital The American Physical Society}

  7. Positron lifetime in vacancy-impurity complexes (*) Section d'Etudes des Solides Irradis, Centre d'Etudes Nuclaires, Boite Postale n 6, 92260 Fontenay aux Roses, France

    E-print Network

    Boyer, Edmond

    L-547 Positron lifetime in vacancy-impurity complexes (*) C. Corbel Section d'Etudes des Solides positon. Abstract. 2014 We calculate the positron lifetime in vacancy-solute (Na, Mg, Zn) complexes in Al-550 15 DÉCEMBRE 1981,1 Classification Physics Abstracts 78.70B 1. Introduction. - The positron

  8. Measurement of the Lambda(+)(c) lifetime

    E-print Network

    Ammar, Raymond G.; Bean, Alice; Besson, David Zeke; Davis, Robin E. P.; Kwak, Nowhan; Zhao, X.

    2001-03-01

    The Lambda (+)(c) lifetime is measured using 9.0 fb(-1) of e(+)e(-) annihilation data collected on or just below the Y (4S) resonance with the CLEO ILV detector at CESR. Using an unbinned maximum likelihood fit, the Lambda (+)(c) lifetime...

  9. Lifetime measurements and tau physics at PEP

    SciTech Connect

    Gladney, L.D.

    1984-05-01

    Recent updates on the measurements of the tau and D/sup 0/ lifetimes by the Mark II Collaboration and on measurements of the tau and B-hadron lifetimes by the MAC Collaboration are presented. A new determination of an upper limit for the tau neutrino mass by the Mark II Collaboration and a recent measurement of Cabibbo-suppressed tau decay branching ratios from the DELCO Collaboration are also presented. 18 references.

  10. Dark matter annihilations and decays after the AMS-02 positron measurements

    NASA Astrophysics Data System (ADS)

    Ibarra, Alejandro; Lamperstorfer, Anna S.; Silk, Joseph

    2014-03-01

    The AMS-02 Collaboration has recently presented high-quality measurements of the cosmic electron and positron fluxes as well as the positron fraction. We use the measurements of the positron flux to derive, for the first time, limits on the dark matter annihilation cross section and lifetime for various final states. Working under the well-motivated assumption that a background positron flux exists from spallations of cosmic rays with the interstellar medium and from astrophysical sources, we find strong limits on the dark matter properties which are competitive, although slightly weaker, than those derived from the positron fraction. Specifically, for dark matter particles annihilating only into e+e- or into ?+?-, our limits on the annihilation cross section are stronger than the thermal value when the dark matter mass is smaller than 100 GeV or 60 GeV, respectively.

  11. Comparative studies of positron annihilation lifetime and coincident Doppler broadening spectra for a binary Cd-based quasicrystal and 1/1-approximant crystal

    SciTech Connect

    Takagiwa, Y.; Kanazawa, I.; Sato, K.; Murakami, H.; Kobayashi, Y.; Tamura, R.; Takeuchi, S. [Department of Physics, Tokyo Gakugei University, 4-1-1 Koganei, Tokyo 184-0051 (Japan); Department of Environmental Science, Tokyo Gakugei University, 4-1-1 Koganei, Tokyo 184-0051 (Japan); National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565 (Japan); Department of Materials Science and Technology, Tokyo University of Science, Noda, Chiba 278-8501 (Japan)

    2006-03-01

    We performed the positron annihilation lifetime and coincident Doppler broadening measurements for binary icosahedral quasicrystal Cd{sub 5.7}Ca and its 1/1-cubic Cd{sub 6}Ca and Cd{sub 6}Yb approximants. Since the obtained positron lifetimes are quite similar to one another, it is likely that the same type of structural vacancies exists in quasicrystal Cd{sub 5.7}Ca and 1/1-cubic Cd{sub 6}Ca and Cd{sub 6}Yb approximants. The vacancy-type defects are concluded to be surrounded mostly by Cd atoms in both quasicrystal Cd{sub 5.7}Ca and its 1/1-cubic approximant Cd{sub 6}Ca from the high-momentum Doppler broadening spectra. In addition, we studied the temperature dependence of the positron annihilation lifetime in the low temperature region from 10 to 300 K for 1/1-cubic approximant Cd{sub 6}Ca and Cd{sub 6}Yb crystals. As a whole, in both 1/1-cubic Cd{sub 6}Ca and Cd{sub 6}Yb approximants the positron lifetime {tau}{sub 1} gradually increases with increasing temperature due to isotropic thermal expansion. However, the positron lifetime {tau}{sub 1} does not change at the order-disorder transition temperature, namely, 100 and 110 K for 1/1-cubic Cd{sub 6}Ca and Cd{sub 6}Yb approximants, respectively. These results suggest that the size of the structural vacancies and local electron density do not change with the ordering.

  12. Measurements of heavy quark and lepton lifetimes

    SciTech Connect

    Jaros, J.A.

    1985-02-01

    The PEP/PETRA energy range has proved to be well-suited for the study of the lifetimes of hadrons containing the b and c quarks and the tau lepton for several reasons. First, these states comprise a large fraction of the total interaction rate in e/sup +/e/sup -/ annihilation and can be cleanly identified. Second, the storage rings have operated at high luminosity and so produced these exotic states copiously. And finally, thanks to the interplay of the Fermi coupling strength, the quark and lepton masses, and the beam energy, the expected decay lengths are in the 1/2 mm range and so are comparatively easy to measure. This pleasant coincidence of cleanly identified and abundant signal with potentially large effects has made possible the first measurements of two fundamental weak couplings, tau ..-->.. nu/sub tau/W and b ..-->.. cW. These measurements have provided a sharp test of the standard model and allowed, for the first time, the full determination of the magnitudes of the quark mixing matrix. This paper reviews the lifetime studies made at PEP during the past year. It begins with a brief review of the three detectors, DELCO, MAC and MARK II, which have reported lifetime measurements. Next it discusses two new measurements of the tau lifetime, and briefly reviews a measurement of the D/sup 0/ lifetime. Finally, it turns to measurements of the B lifetime, which are discussed in some detail. 18 references, 14 figures, 1 table.

  13. Investigation of microstructural changes in polyetherether-ketone films at cryogenic temperatures by positron lifetime spectroscopy

    NASA Technical Reports Server (NTRS)

    Singh, Jag J.; Eftekhari, Abe; St.clair, Terry L.; Sprinkle, Danny R.

    1991-01-01

    Microstructural changes in Polyetherether-ketone (PEEK) films were investigated in the temperature ranges of 23 to -196 C, using Positron Lifetime Spectroscopy (PLS) technique. It was determined that the total free volume decreases by about 46 percent in amorphous PEEK samples and about 36 percent in semicrystalline PEEK samples when they are cooled down from room temperature to liquid nitrogen (LN2) temperature. If this trend in reduction in free volume with decreasing temperature continues, as expected, it is surmised that PEEK will be able to withstand cooling down to liquid hydrogen (LH2) temperature without any detrimental effect on its diffusivity for liquid hydrogen.

  14. Alkali-doped heavy metal fluoride glasses studied by positron annihilation lifetime spectroscopy

    Microsoft Academic Search

    A. J. Hill; P. J. Newman; J. Javorniczky; D. R. MacFarlane

    1995-01-01

    Heavy metal fluoride glasses of varying alkali metal fluoride have been studied by positron annihilation lifetime spectroscopy. The alkali series 53ZrF4 · (40 - x)BaF2 · 4LaF3 · 3AlF3 · xLiF and 53ZrF4 · (40 - x)BaF2 · 4LaF3 · 3AlF3 · xCsF are compared with the mixed alkali series 53ZrF4 · 20BaF2 · 4LaF3 · 4LaF3 · 3AlF3 ·

  15. Photo-degradation of Lexan polycarbonate studied using positron lifetime spectroscopy

    SciTech Connect

    Hareesh, K.; Sanjeev, Ganesh [Microtron Centre, Department of Physics, Mangalore University, Mangalagangotri-574199 (India); Pandey, A. K. [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085 (India); Meghala, D.; Ranganathaiah, C. [Department of Studies in Physics, University of Mysore, Manasagangotri-570006 (India)

    2013-02-05

    The free volume properties of pristine and UV irradiated Lexan polycarbonate have been investigated using Positron Lifetime Spectroscopy (PLS). The decrease in o-Ps life time and free volume size of irradiated sample is attributed to free volume modification and formation of more stable free radicals. These free radicals are formed due to the breakage of C-O bonds in Lexan polycarbonate after irradiation. This is also supported by the decrease in the intensity of C-O bond after exposure to UV-radiation as studied from Fourier Transform Infrared (FTIR) spectroscopy and it also shows that benzene ring does not undergo any changes after irradiation.

  16. Lifetime measurement in ^170Yb

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Krücken, R.; Beausang, C. W.; Casten, R. F.; Cooper, J. R.; Cederkäll, J.; Caprio, M.; Novak, J. R.; Zamfir, N. V.; Barton, C.

    1999-10-01

    The nature of the low lying K^?=0^+ excitations in deformed nuclei have recently been subject of intense discussion. In this context we present results from a Coulomb excitation experiment on ^170Yb using a 70MeV ^16O beam on a gold backed, 1.5 mg/cm^2 thick ^170Yb target. The beam was delivered by the ESTU tandem accelerator of WNSL at Yale University. Gamma rays were detected by the YRAST Ball array in coincidence with back-scattered ^16O particles, which were detected in an array of 8 solar cells. Lineshapes were observed for several transitions from collective states in ^170Yb and the lifetimes for those states were extracted using a standard DSAM analysis. The results will be presented together with a short introduction to the solar cell array at Yale (SCARY) that was used to make angular selection of the excited ^170Yb nuclei. This work is supported by the US-DOE under grant numbers DE-FG02-91ER-40609 and DE-FG02-88ER-40417.

  17. Measurement of the Omega0(c) lifetime

    SciTech Connect

    Iori, M.; Ayan, A.S.; Akgun, U.; Alkhazov, G.; Amaro-Reyes, J.; Atamantchouk, A.G.; Balatz, M.Y.; Blanco-Covarrubias, A.; Bondar, N.F.; Cooper, P.S.; Dauwe, L.J.; /Ball State U. /Bogazici U. /Carnegie Mellon U. /Rio de Janeiro, CBPF /Fermilab /Serpukhov, IHEP /Beijing, Inst. High Energy Phys. /Moscow, ITEP /Heidelberg, Max Planck Inst. /Moscow State U. /St. Petersburg, INP

    2007-01-01

    The authors report a precise measurement of the {Omega}{sub c}{sup 0} lifetime. The data were taken by the SELEX (E781) experiment using 600 GeV/c {Sigma}{sup -}, {pi}{sup -} and p beams. The measurement has been made using 83 {+-} 19 reconstructed {Omega}{sub c}{sup 0} in the {Omega}{sup -} {pi}{sup -}{pi}{sup +}{pi}{sup +} and {Omega}{sup -} {pi}{sup +} decay modes. The lifetime of the {Omega}{sub c}{sup 0} is measured to be 65 {+-} 13(stat) {+-} 9(sys) fs.

  18. TRENDS IN LIFETIME MEASUREMENTS Dieter K. Schroder

    E-print Network

    Schroder, Dieter K.

    necessary data processing built into the equipment. The silicon crystal growers measured lifetimes the interstitial iron, Fei, state in boron-doped wafers, was it possible to determine the iron density in a wafer.3 measurements are described and are shown to be useful for thin layer, e.g., epitaxial or silicon

  19. Microdefects in Al{sub 2}O{sub 3} films and interfaces revealed by positron lifetime spectroscopy

    SciTech Connect

    Xu, J.; Somieski, B.; Hulett, L.D.; Pint, B.A.; Tortorelli, P.F. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6142 (United States)] [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6142 (United States); Suzuki, R.; Ohdaira, T. [Electrotechnical Laboratory, 1-1-4 Umezono, Tsukuba, Ibaraki 305 (Japan)] [Electrotechnical Laboratory, 1-1-4 Umezono, Tsukuba, Ibaraki 305 (Japan)

    1997-11-01

    We have studied microdefects and interfaces of Al{sub 2}O{sub 3} films on iron and nickel aluminide substrates using variable-energy positron lifetime spectroscopy. Di-vacancies, vacancy clusters, and microvoids were observed in the oxide scales. Their sizes and distributions were determined by the nature of the process used to synthesize the alumina film, and influenced by the composition of the alloy substrates. For oxide{endash}iron aluminide interfaces, positron lifetimes are longer than those for the alumina layer itself, suggesting a greater defect concentration at such sites. {copyright} {ital 1997 American Institute of Physics.}

  20. Confined water in controlled pore glass CPG-10-120 studied by positron annihilation lifetime spectroscopy and differential scanning calorimetry

    NASA Astrophysics Data System (ADS)

    Šauša, O.; Mat'ko, I.; Illeková, E.; Macová, E.; Berek, D.

    2015-06-01

    The solidification and melting of water confined in the controlled pore glass (CPG) with average pore size 12.6 nm has been studied by differential scanning calorimetry (DSC) and positron annihilation lifetime spectroscopy (PALS). The fully-filled sample of CPG by water as well as the samples of CPG with different content of water were used. The measurements show the presence of amorphous and crystalline phases of water in this type and size of pores, freezing point depression of a confined liquid and presence of certain transitions at lower temperatures, which could be detected only for cooling regime. The localization of confined water in the partially filled pores of CPG at room temperature was studied.

  1. Per-fluorinated sulfonic acid/PTFE copolymer studied by positron annihilation lifetime and gas permeation techniques

    NASA Astrophysics Data System (ADS)

    Mohamed, Hamdy F. M.; Abdel-Hady, E. E.; Ohira, A.

    2015-06-01

    The mechanism of gas permeation in per-fluorinated sulfonic acid/PTFE copolymer Fumapem® membranes for polymer electrolyte fuel cells has been investigated from the viewpoint of free volume. Three different samples, Fumapem® F-950, F-1050 and F-14100 membranes with ion exchange capacity (IEC) = 1.05, 0.95 and 0.71 meq/g, respectively were used after drying. Free volume was quantified using the positron annihilation lifetime (PAL) technique and gas permeabilities were measured for O2 and H2 as function of temperature. Good linear correlation between the logarithm of the permeabilities at different temperatures and reciprocal free volume indicate that gas permeation in dry Fumapem® is governed by the free volume. Nevertheless permeabilities are much smaller than the corresponding flexible chain polymer with a similar free volume size due to stiff chains of the perfluoroethylene backbone.

  2. A measurement of the tau lepton lifetime

    Microsoft Academic Search

    M. Battle; J. Ernst; H. Kroha; S. Roberts; K. Sparks; E. H. Thorndike; C.-H. Wang; R. Stroynowski; M. Artuso; M. Goldberg; N. Horwitz; R. Kennett; G. C. Moneti; F. Muheim; S. Playfer; Y. Rozen; P. Rubin; T. Skwarnicki; S. Stone; M. Thulasidas; W.-M. Yao; G. Zhu; A. V. Bernes; J. Bartelt; S. E. Csorna; Z. Egyed; V. Jain; T. Letson; M. D. Mestayer; P. Sheldon; D. S. Akerib; B. Barish; M. Chadha; D. F. Cowen; G. Eigen; J. S. Miller; J. Urheim; A. J. Weinstein; D. Acosta; G. Masek; B. Ong; H. Paar; M. Sivertz; A. Bean; J. Gronberg; R. Kutschke; S. Menary; R. J. Morrison; H. Nelson; J. Richman; H. Tajima; D. Schmidt; D. Sperka; M. Witherell; M. Procario; M. Daoudi; W. T. Ford; D. R. Johnson; K. Lingel; M. Lohner; P. Rankin; J. G. Smith; J. P. Alexander; C. Bebek; K. Berkelman; D. Besson; T. E. Browder; D. G. Cassel; E. Cheu; D. M. Coffman; P. S. Drell; R. Ehrlich; R. S. Galik; M. Garcia-Sciveres; B. Geiser; B. Gittelman; S. W. Gray; A. M. Halling; D. L. Hartill; B. K. Heltsley; K. Honscheid; C. Jones; J. Kandaswamy; N. Katayama; P. C. Kim; D. L. Kreinick; J. D. Lewis; G. S. Ludwig; J. Masui; J. Mevissen; N. B. Mistry; S. Nandi; C. R. Ng; E. Nordberg; C. O'Grady; J. R. Patterson; D. Peterson; M. Pisharody; D. Riley; M. Sapper; M. Selen; A. Silverman; H. Worden; M. Worris; F. Würthwein; P. Avery; A. Freyberger; J. Rodriguez; R. Stephens; J. Yelton; D. Cinabro; S. Henderson; K. Kinoshita; T. Liu; F. M. Pipkin; M. Saulnier; R. Wilson; J. Wolinski; D. Xiao; H. Yamamoto; A. J. Sadoff; R. Ammar; S. Ball; P. Baringer; D. Coppage; N. Copty; R. Davis; P. Haas; N. Hancock; M. Kelly; N. Kwak; H. Lam; S. Ro; Y. Kubota; M. Lattery; J. K. Nelson; D. Perticone; R. Poling; S. Schrenk; R. Wang; M. S. Alam; I. J. Kim; W. C. Li; B. Nemati; J. J. O'Neill; V. Romero; H. Severini; C. R. Sun; P.-N. Wang; M. M. Zoeller; G. Crawford; R. Fulton; K. K. Gan; T. Jensen; H. Kagan; R. Kass; J. Lee; R. Malchow; F. Morrow; M. Sung; C. White; J. Whitmore; P. Wilson; F. Butler; X. Fu; G. Kalbfleisch; M. Lambrecht; P. Skubic; J. Snow; P.-L. Wang; D. Bortoletto; D. N. Brown; J. Dominick; R. L. McIlwain; T. Miao; D. H. Miller; M. Modesitt; S. F. Schaffner; E. I. Shibata; I. P. J. Shipsey

    1992-01-01

    Using tau+tau- pairs in which one tau decays to leptons and the other decays to 3 charged particles we present a high statistics measurement of the tau lepton lifetime. The data used in this analysis were collected with the CLEO detector at CESR and consist of an integrated luminosity of 429 pb-1 taken at, above, and below the Upsilon (4S).

  3. Neutron lifetime measured with stored ultracold neutrons

    SciTech Connect

    Mampe, W.; Ageron, P.; Bates, C.; Pendlebury, J. M.; Steyerl, A.

    1989-08-07

    The neutron lifetime has been measured by counting the neutrons remaining in a fluid-walled bottle as a function of the duration of storage. Losses of neutrons caused by the wall reflections are eliminated by varying the bottle volume-to-surface ratio. The result obtained is /tau//sub /beta//=887.6/plus minus/3 s.

  4. Measurement of the F-meson lifetime

    SciTech Connect

    Jung, C.; Abachi, S.; Akerlof, C.; Baringer, P.; Beltrami, I.; Blockus, D.; Bonvicini, G.; Brabson, B.; Brom, J.M.; Bylsma, B.G.

    1986-04-28

    The lifetime of the F/sup + -/ meson has been measured to be (3.5/sub -1.8//sup +2.4/ +- 0.9) x 10 /sup -13/ s by means of the F/sup + -/..-->..phi..pi../sup + -/ decay mode. The measurement was made with the high resolution spectrometer at the SLAC e/sup +/e/sup -/ storage ring PEP at a center-of-mass energy of 29 GeV.

  5. A measurement of the tau lifetime

    Microsoft Academic Search

    P. Abreu; W. Adam; T. Adye; E. Agasi; R. Aleksan; G. D. Alekseev; A. Algeri; P. Allen; S. Almehed; S. J. Alvsvaag; U. Amaldi; E. G. Anassontzis; A. Andreazza; P. Antilogus; W.-D. Apel; R. J. Apsimon; Y. Arnoud; B. Å; J.-E. Augustin; A. Augustinus; P. Baillon; P. Bambade; F. Barao; R. Barate; G. Barbiellini; D. Y. Bardin; G. J. Barker; A. Baroncelli; O. Barring; J. A. Barrio; W. Bartl; M. J. Bates; M. Battaglia; M. Baubillier; K.-H. Becks; C. J. Beeston; M. Begalli; P. Beilliere; Yu. Belokopytov; P. Beltran; D. Benedic; A. C. Benvenuti; M. Berggren; D. Bertrand; F. Bianchi; M. S. Bilenky; P. Billoir; J. Bjarne; D. Bloch; S. Blyth; V. Bocci; P. N. Bogolubov; T. Bolognese; M. Bonesini; W. Bonivento; P. S. L. Booth; G. Borisov; H. Borner; C. Bosio; B. Bostjancic; S. Bosworth; O. Botner; B. Bouquet; C. Bourdarios; T. J. V. Bowcock; M. Bozzo; S. Braibant; P. Branchini; K. D. Brand; R. A. Brenner; H. Briand; C. Bricman; R. C. A. Brown; N. Brummer; J.-M. Brunet; L. Bugge; T. Buran; H. Burmeister; J. A. M. A. Buytaert; M. Caccia; M. Calvi; A. J. Camacho Rozas; R. Campion; T. Camporesi; V. Canale; F. Cao; F. Carena; L. Carroll; M. V. Castillo Gimenez; A. Cattai; F. R. Cavallo; L. Cerrito; V. Chabaud; A. Chan; Ph. Charpentier; L. Chaussard; J. Chauveau; P. Checchia; G. A. Chelkov; L. Chevalier; P. Chliapnikov; V. Chorowicz; J. T. M. Chrin; M. P. Clara; P. Collins; J. L. Contreras; R. Contri; E. Cortina; G. Cosme; F. Couchot; H. B. Crawley; D. Crennell; G. Crosetti; M. Crozon; J. Cuevas Maestro; S. Czellar; E. Dahl-Jensen; B. Dalmagne; M. Dam; G. Damgaard; G. Darbo; E. Daubie; A. Daum; P. D. Dauncey; M. Davenport; P. David; J. Davies; W. Da Silva; C. Defoix; P. Delpierre; N. Demaria; A. De Angelis; H. De Boeck; W. De Boer; C. De Clercq; M. D. M. De Fez Laso; N. De Groot; C. De La Vaissiere; B. De Lotto; A. De Min; H. Dijkstra; L. Di Ciaccio; F. Djama; J. Dolbeau; M. Donszelmann; K. Doroba; M. Dracos; J. Drees; M. Dris; Y. Dufour; F. Dupont; L.-O. Eek; P. A.-M. Eerola; R. Ehret; T. Ekelof; G. Ekspong; A. Elliot Peisert; J.-P. Engel; N. Ershaidat; D. Fassouliotis; M. Feindt; A. Fenyuk; M. Fernandez Alonso; A. Ferrer; T. A. Filippas; A. Firestone; H. Foeth; E. Fokitis; F. Fontanelli; K. A. J. Forbes; J.-L. Fousset; S. Francon; B. Franek; P. Frenkiel; D. C. Fries; A. G. Frodesen; R. Fruhwirth; F. Fulda-Quenzer; K. Furnival; H. Furstenau; J. Fuster; D. Gamba; C. Garcia; J. Garcia; C. Gaspar; U. Gasparini; Ph. Gavillet; E. N. Gazis; J.-P. Gerber; P. Giacomelli; R. Gokieli; B. Golob; V. M. Golovatyuk; J. J. Gomez Y Cadenas; A. Goobar; G. Gopal; M. Gorski; V. Gracco; A. Grant; F. Grard; E. Graziani; G. Grosdidier; E. Gross; P. Grosse-Wiesmann; B. Grossetete; S. Gumenyuk; J. Guy; U. Haedinger; F. Hahn; M. Hahn; S. Haider; Z. Hajduk; A. Hakansson; A. Hallgren; K. Hamacher; G. Hamel De Monchenault; W. Hao; F. J. Harris; V. Hedberg; T. Henkes; J. J. Hernandez; P. Herquet; H. Herr; T. L. Hessing; I. Hietanen; C. O. Higgins; E. Higon; H. J. Hilke; S. D. Hodgson; T. Hofmokl; R. Holmes; S.-O. Holmgren; D. Holthuizen; P. F. Honore; J. E. Hooper; M. Houlden; J. Hrubec; K. Huet; P. O. Hulth; K. Hultqvist; P. Ioannou; P.-S. Iversen; J. N. Jackson; P. Jalocha; G. Jarlskog; P. Jarry; B. Jean-Marie; E. K. Johansson; D. Johnson; M. Jonker; L. Jonsson; P. Juillot; G. Kalkanis; G. Kalmus; F. Kapusta; M. Karlsson; E. Karvelas; S. Katsanevas; E. C. Katsoufis; R. Keranen; J. Kesteman; B. A. Khomenko; N. N. Khovanski; B. King; N. J. Kjaer; H. Klein; A. Klovning; P. Kluit; A. Koch-Mehrin; J. H. Koehne; B. Koene; P. Kokkinias; M. Koratzinos; K. Korcyl; A. V. Korytov; V. Kostioukhine; C. Kourkoumelis; O. Kouznetsov; P. H. Kramer; J. Krolikowski; I. Kronkvist; U. Kruener-Marquis; W. Kucewicz; K. Kulka; K. Kurvinen; C. Lacasta; C. Lambropoulos; J. W. Lamsa; L. Lanceri; V. Lapin; J.-P. Laugier; R. Lauhakangas; G. Leder; F. Ledroit; R. Leitner; Y. Lemoigne; J. Lemonne; G. Lenzen; V. Lepeltier; T. Lesiak; J. M. Levy; E. Lieb; D. Liko; J. Lindgren; R. Lindner; A. Lipniacka; I. Lippi; B. Loerstad; M. Lokajicek; J. G. Loken; A. Lopez-Fernandez; M. A. Lopez Aguera; M. Los; D. Loukas; J. J. Lozano; P. Lutz; L. Lyons; G. Maehlum; J. Maillard; A. Maio; A. Maltezos; F. Mandl; J. Marco; M. Margoni; J.-C. Marin; A. Markou; T. Maron; S. Marti; L. Mathis; F. Matorras; C. Matteuzzi; G. Matthiae; M. Mazzucato; M. Mc Cubbin; R. Mc Nay; R. Mc Nulty; G. Meola; C. Meroni; W. T. Meyer; M. Michelotto; I. Mikulec; L. Mirabito; W. A. Mitaroff; G. V. Mitselmakher; U. Mjoernmark; T. Moa; R. Moeller; K. Moenig; M. R. Monge; P. Morettini; H. Mueller; W. J. Murray; G. Myatt; F. L. Navarria; P. Negri; B. S. Nielsen; B. Nijjhar; V. Nikolaenko; P. E. S. Nilsen; P. Niss; V. Obraztsov; A. G. Olshevski; R. Orava; A. Ostankov; K. Osterberg; A. Ouraou; M. Paganoni; R. Pain; Th. D. Papadopoulou; L. Pape; F. Parodi; A. Passeri

    1993-01-01

    The tau lepton lifetime is measured using four different methods with the DELPHI detector. Three measurements using one prong decays are combined, accounting for correlations, resulting in tautau=298 +\\/-7 (stat.)+\\/-4 (syst.) fs while the decay length distribution of three prong decays gives pipi=298+\\/-13 (stat)+\\/-(syst.) fs. The combined result is tautau=298+\\/-7 fs. The ratio of the Fermi coupling constant from tau

  6. Mass and Lifetime Measurements in Storage Rings

    SciTech Connect

    Weick, H.; Beckert, K.; Beller, P.; Bosch, F.; Dimopoulou, C.; Kozhuharov, C.; Kurcewicz, J.; Mazzocco, M.; Nociforo, C.; Nolden, F.; Steck, M.; Sun, B.; Winkler, M. [Gesellschaft fuer Schwerionenforschung mbH, 64291 Darmstadt (Germany); Brandau, C.; Chen, L.; Geissel, H.; Knoebel, R.; Litvinov, S. A.; Litvinov, Yu. A.; Scheidenberger, C. [Gesellschaft fuer Schwerionenforschung mbH, 64291 Darmstadt (Germany); II. Phys. Institut, Justus-Liebig-Universitaet Giessen, 35392 Giessen (Germany)] (and others)

    2007-05-22

    Masses of nuclides covering a large area of the chart of nuclides can be measured in storage rings where many ions circulate at the same time. In this paper the recent progress in the analysis of Schottky mass spectrometry data is presented as well as the technical improvements leading to higher accuracy for isochronous mass measurements with a time-of-flight detector. The high sensitivity of the Schottky method down to single ions allows to measure lifetimes of nuclides by observing mother and daughter nucleus simultaneously. In this way we investigated the decay of bare and H-like 140Pr. As we could show the lifetime can be even shortened compared to those of atomic nuclei despite of a lower number of electrons available for internal conversion or electron capture.All these techniques will be implemented with further improvements at the storage rings of the new FAIR facility at GSI in the future.

  7. Free volume of mixed cation borosilicate glass sealants elucidated by positron annihilation lifetime spectroscopy and its correlation with glass properties

    NASA Astrophysics Data System (ADS)

    Ojha, Prasanta K.; Rath, Sangram K.; Sharma, Sandeep K.; Sudarshan, Kathi; Pujari, Pradeep K.; Chongdar, Tapas K.; Gokhale, Nitin M.

    2015-01-01

    The role of La+3/Sr+2 ratios, which is varied from 0.08 to 5.09, on density, molar volume, packing fraction, free volume, thermal and electrical properties in strontium lanthanum aluminoborosilicate based glass sealants intended for solid oxide fuel cell (SOFC) applications is evaluated. The studies reveal expansion of the glass network evident from increasing molar volume and decreasing packing fraction of glasses with progressive La+3 substitutions. The molecular origin of these macroscopic structural features can be accounted for by the free volume parameters measured from positron annihilation lifetime spectroscopy (PALS). The La+3 induced expanded glass networks show increased number of subnanoscopic voids with larger sizes, as revealed from the ortho-positronium (o-Ps) lifetime and its intensity. A remarkably direct correspondence between the molar volume and fractional free volume trend is established with progressive La2O3 substitution in the glasses. The effect of these structural changes on the glass transition temperature, softening temperature, coefficient of thermal expansion, thermal stability as well as electrical conductivity has been studied.

  8. Electron beam induced microstructural changes and electrical conductivity in Bakelite polymer RPC detector material: A positron lifetime study

    NASA Astrophysics Data System (ADS)

    Aneesh Kumar, K. V.; Ningaraju, S.; Munirathnamma, L. M.; Ravikumar, H. B.; Ranganathaiah, C.

    2015-06-01

    In order to explore the structural modification induced electrical conductivity, samples of Bakelite RPC polymer detector materials were exposed to 8 MeV of electron beam with the irradiation dose from 20 kGy to 100 kGy in steps of 20 kGy. The microstructural changes upon electron beam irradiation have been studied using Positron Annihilation Lifetime Spectroscopy (PALS) and Fourier Transform Infrared (FTIR) Spectroscopy. Positron lifetime parameters viz., o-Ps lifetime and its intensity show chain scission at lower doses (20 kGy, 40 kGy) followed by cross-linking beyond 40 kGydue to the radical reactions. The reduction in electrical conductivity of Bakelite material beyond 60 kGy is correlated to the conducting pathways and cross-links in the polymer matrix. The appropriate doses of electron beam irradiation of Bakelite material may reduce the leakage current and hence improves the performance of the detector.

  9. Positron annihilation measurements in high-energy alpha-irradiated n-type Gallium Arsenide

    NASA Astrophysics Data System (ADS)

    Pan, Sandip; Mandal, Arunava; Roychowdhury, Anirban; SenGupta, Asmita

    2015-07-01

    Positron annihilation lifetime spectroscopy and Doppler broadening annihilation line-shape measurements have been carried out in 40-MeV alpha-irradiated n-type GaAs. After irradiation, the sample has been subjected to an isochronal annealing over temperature region of 25-800 °C with an annealing time of 30 min at each set temperature. After each annealing, the positron measurements are taken at room temperature. Formation of radiation-induced defects and their recovery with annealing temperature are investigated. The lifetime spectra of the irradiated sample have been fitted with two lifetimes. The average positron lifetime ?avg = 244 ps at room temperature after irradiation indicates the presence of defects, and the value of ?2 (262 ps) at room temperature suggests that the probable defects are mono-vacancies. Two distinct annealing stages in ?avg at 400-600 °C and at 650-800 °C are observed. The variations in line-shape parameter ( S) and defect-specific parameter ( R) during annealing in the temperature region 25-800 °C resemble the behaviour of ?avg indicating the migration of vacancies, formation of vacancy clusters and the disappearance of defects between 400 and 800 °C.

  10. Lifetime measurements of states in O15

    NASA Astrophysics Data System (ADS)

    Galinski, N.; Sjue, S. K. L.; Ball, G. C.; Cross, D. S.; Davids, B.; Al Falou, H.; Garnsworthy, A. B.; Hackman, G.; Hager, U.; Howell, D. A.; Jones, M.; Kanungo, R.; Kshetri, R.; Leach, K. G.; Leslie, J. R.; Moukaddam, M.; Orce, J. N.; Rand, E. T.; Ruiz, C.; Ruprecht, G.; Schumaker, M. A.; Svensson, C. E.; Triambak, S.; Unsworth, C. D.

    2014-09-01

    At low stellar temperatures the energy release due to the CN cycle is regulated by its slowest reaction 14N(p,?)15O, the rate of which strongly depends on the subthreshold resonance at Ec.m.=-504keV, which corresponds to the 6.79 MeV state in 15O. By using the Doppler-shift attenuation method and the 3He(16O,?)15O reaction to populate the state, we obtained an upper limit on the lifetime of this state of ? <1.8fs [68.3% confidence level (C.L.)]. In addition we measured the lifetimes of the 6.18 and 6.86 MeV states to be ? <2.5 and ? =13.3-1.2+0.9fs, respectively (68.3% C.L.), in good agreement with the literature.

  11. Physical Selectivity of Molecularly Imprinted polymers evaluated through free volume size distributions derived from Positron Lifetime Spectroscopy

    NASA Astrophysics Data System (ADS)

    Pasang, T.; Ranganathaiah, C.

    2015-06-01

    The technique of imprinting molecules of various sizes in a stable structure of polymer matrix has derived multitudes of applications. Once the template molecule is extracted from the polymer matrix, it leaves behind a cavity which is physically (size and shape) and chemically (functional binding site) compatible to the particular template molecule. Positron Annihilation Lifetime Spectroscopy (PALS) is a well known technique to measure cavity sizes precisely in the nanoscale and is not being used in the field of MIPs effectively. This method is capable of measuring nanopores and hence suitable to understand the physical selectivity of the MIPs better. With this idea in mind, we have prepared molecular imprinted polymers (MIPs) with methacrylicacid (MAA) as monomer and EGDMA as cross linker in different molar ratio for three different size template molecules, viz. 4-Chlorophenol (4CP)(2.29 Å), 2-Nephthol (2NP) (3.36 Å) and Phenolphthalein (PP) (4.47Å). FTIR and the dye chemical reactions are used to confirm the complete extraction of the template molecules from the polymer matrix. The free volume size and its distribution have been derived from the measured o-Ps lifetime spectra. Based on the free volume distribution analysis, the percentage of functional cavities for the three template molecules are determined. Percentage of functional binding cavities for 4-CP molecules has been found out to be 70.2% and the rest are native cavities. Similarly for 2NP it is 81.5% and nearly 100% for PP. Therefore, PALS method proves to be very precise and accurate for determining the physical selectivity of MIPs.

  12. Positron annihilation lifetime spectroscopy (PALS): a probe for molecular organisation in self-assembled biomimetic systems.

    PubMed

    Fong, Celesta; Dong, Aurelia W; Hill, Anita J; Boyd, Ben J; Drummond, Calum J

    2015-07-01

    Positron annihilation lifetime spectroscopy (PALS) has been shown to be highly sensitive to conformational, structural and microenvironmental transformations arising from subtle geometric changes in molecular geometry in self-assembling biomimetic systems. The ortho-positronium (oPs) may be considered an active probe that can provide information on intrinsic packing and mobility within low molecular weight solids, viscous liquids, and soft matter systems. In this perspective we provide a critical overview of the literature in this field, including the evolution of analysis software and experimental protocols with commentary upon the practical utility of PALS. In particular, we discuss how PALS can provide unique insight into the macroscopic transport properties of several porous biomembrane-like nanostructures and suggest how this insight may provide information on the release of drugs from these matrices to aid in developing therapeutic interventions. We discuss the potentially exciting and fruitful application of this technique to membrane dynamics, diffusion and permeability. We propose that PALS can provide novel molecular level information that is complementary to conventional characterisation techniques. PMID:25948334

  13. Level Lifetime Measurements in ^150Sm

    NASA Astrophysics Data System (ADS)

    Barton, C. J.; Krücken, R.; Beausang, C. W.; Caprio, M. A.; Casten, R. F.; Cooper, J. R.; Hecht, A. A.; Newman, H.; Novak, J. R.; Pietralla, N.; Wolf, A.; Zyromski, K. E.; Zamfir, N. V.; Börner, H. G.

    2000-10-01

    Shape/phase coexistence and the evolution of structure in the region around ^152Sm have recently been of great interest. Experiments performed at WNSL, Yale University, measured the lifetime of low spin states in a target of ^150Sm with the recoil distance method (RDM) and the Doppler-shift attenuation method (DSAM). The low spin states, both yrast and non-yrast, were populated via Coulomb excitation with a beam of ^16O. The experiments were performed with the NYPD plunger in conjunction with the SPEEDY ?-ray array. The SCARY array of solar cells was used to detect backward scattered projectiles, selecting forward flying Coulomb excited target nuclei. The measured lifetimes yield, for example, B(E2) values for transitions such as the 2^+2 arrow 2^+1 and the 2^+3 arrow 0^+_1. Data from the RDM measurment and the DSAM experiment will be presented. This work was supported by the US DOE under grants DE-FG02-91ER-40609 and DE-FG02-88ER-40417.

  14. Photoluminescence lifetime measurements in InP wafers

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Jenkins, Phillip; Weinberg, Irving

    1991-01-01

    A simple apparatus to measure the minority carrier lifetime in InP has been developed. The technique stimulates the sample with a short pulse of light from a diode laser and measures the photoluminescence decay to extract the minority carrier lifetime. The photoluminescence lifetime in InP as a function of doping on both n- and p-type material is examined. The results also show a marked difference in the lifetime of n-type InP and p-type InP of similar doping levels. N-type InP shows a lifetime considerably longer than the expected radiative limited lifetime.

  15. First measurement of the lifetime of the ? c0

    NASA Astrophysics Data System (ADS)

    Frabetti, P. L.; Cheung, H. W. K.; Cumalat, J. P.; Dallapiccola, C.; Ginkel, J. F.; Greene, S. V.; Johns, W. E.; Nehring, M. S.; Butler, J. N.; Cihangir, S.; Gaines, I.; Garbincius, P. H.; Garren, L.; Gourlay, S. A.; Harding, D. J.; Kasper, P.; Kreymer, A.; Lebrun, P.; Shukla, S.; Vittone, M.; Bianco, S.; Fabbri, F. L.; Sarwar, S.; Zallo, A.; Culbertson, R.; Gardner, R. W.; Greene, R.; Wiss, J.; Alimonti, G.; Bellini, G.; Boschini, M.; Brambilla, D.; Caccianiga, B.; Cinquini, L.; Di Corato, M.; Giammarchi, M.; Inzani, P.; Leveraro, F.; Malvezzi, S.; Menasce, D.; Meroni, E.; Moroni, L.; Pedrini, D.; Perasso, L.; Prelz, F.; Sala, A.; Sala, S.; Torretta, D.; Buchholz, D.; Claes, D.; Gobbi, B.; O'Reilly, B.; Bishop, J. M.; Cason, N. M.; Kennedy, C. J.; Kim, G. N.; Lin, T. F.; Puseljic, D. L.; Ruchti, R. C.; Shephard, W. D.; Swiatek, J. A.; Wu, Z. Y.; Arena, V.; Boca, G.; Castoldi, C.; Gianini, G.; Ratti, S. P.; Riccardi, C.; Viola, L.; Vitulo, P.; Lopez, A.; Grim, G. P.; Paolone, V. S.; Yager, P. M.; Wilson, J. R.; Sheldon, P. D.; Davenport, F.; Blackett, G. R.; Danyo, K.; Pisharody, M.; Handler, T.; Cheon, B. G.; Kang, J. S.; Kim, K. Y.; E687 Collaboration

    1995-02-01

    We present the first measurement of the lifetime of the ? c0 baryon. The data were collected in the Fermilab high energy photoproduction experiment E687. The measured lifetime is ? = 86 -20+27(stat.) ± 28(syst.) fr. Thus the ? c0 has one of the shorter lifetimes among the weakly decaying singly charmed baryons.

  16. MuLan, a part-per-million measurement of the positive muon lifetime

    NASA Astrophysics Data System (ADS)

    Gorringe, Tim

    2010-11-01

    We report the results from a part-per-million measurement of the positive muon lifetime ??, and a commensurate determination of the Fermi constant GF, by the MuLan Collaboration. The Fermi constant governs the rates of all weak interaction processes and, together with the fine structure constant ? and the Z-boson mass MZ, fixes the electroweak sector of the Standard Model. Additionally, precise knowledge of the free muon lifetime ?? is necessary for interpreting the results from ongoing lifetime measurements of muonic hydrogen and deuterium atoms. The MuLan experiment was conducted at the Paul Scherrer Institute in Villigen, Switzerland using a pulsed surface muon beam, in-vacuum muon-stopping targets, and a large acceptance, finely segmented, fast timing, scintillator array. The scintillator pulses were recorded by 500 MHz, 8-bit waveform digitizers and stored by a high-speed data acquisition system. A total of ˜10^12 decay positrons from muon stops in both a magnetized iron alloy target and a crystal quartz target were recorded. Thorough studies were conducted of systematic effects from positron pulse pileup, muon spin rotation, and other sources. The measured lifetimes from the two different targets are in excellent agreement and together yield a measurement of ?? to better than 1.3 ppm and a determination of GF to better than 0.8 ppm.

  17. Cosmic-Ray Positron Energy Spectrum Measured by PAMELA

    NASA Astrophysics Data System (ADS)

    Adriani, O.; Barbarino, G. C.; Bazilevskaya, G. A.; Bellotti, R.; Bianco, A.; Boezio, M.; Bogomolov, E. A.; Bongi, M.; Bonvicini, V.; Bottai, S.; Bruno, A.; Cafagna, F.; Campana, D.; Carbone, R.; Carlson, P.; Casolino, M.; Castellini, G.; De Donato, C.; De Santis, C.; De Simone, N.; Di Felice, V.; Formato, V.; Galper, A. M.; Karelin, A. V.; Koldashov, S. V.; Koldobskiy, S. A.; Krutkov, S. Y.; Kvashnin, A. N.; Leonov, A.; Malakhov, V.; Marcelli, L.; Martucci, M.; Mayorov, A. G.; Menn, W.; Mergé, M.; Mikhailov, V. V.; Mocchiutti, E.; Monaco, A.; Mori, N.; Munini, R.; Osteria, G.; Palma, F.; Papini, P.; Pearce, M.; Picozza, P.; Pizzolotto, C.; Ricci, M.; Ricciarini, S. B.; Rossetto, L.; Sarkar, R.; Scotti, V.; Simon, M.; Sparvoli, R.; Spillantini, P.; Stochaj, S. J.; Stockton, J. C.; Stozhkov, Y. I.; Vacchi, A.; Vannuccini, E.; Vasilyev, G. I.; Voronov, S. A.; Yurkin, Y. T.; Zampa, G.; Zampa, N.; Zverev, V. G.

    2013-08-01

    Precision measurements of the positron component in the cosmic radiation provide important information about the propagation of cosmic rays and the nature of particle sources in our Galaxy. The satellite-borne experiment PAMELA has been used to make a new measurement of the cosmic-ray positron flux and fraction that extends previously published measurements up to 300 GeV in kinetic energy. The combined measurements of the cosmic-ray positron energy spectrum and fraction provide a unique tool to constrain interpretation models. During the recent solar minimum activity period from July 2006 to December 2009, approximately 24 500 positrons were observed. The results cannot be easily reconciled with purely secondary production, and additional sources of either astrophysical or exotic origin may be required.

  18. The cosmic-ray positron energy spectrum measured by PAMELA

    E-print Network

    Adriani, O; Bazilevskaya, G A; Bellotti, R; Bianco, A; Boezio, M; Bogomolov, E A; Bongi, M; Bonvicini, V; Bottai, S; Bruno, A; Cafagna, F; Campana, D; Carbone, R; Carlson, P; Casolino, M; Castellini, G; De Donato, C; De Santis, C; De Simone, N; Di Felice, V; Formato, V; Galper, A M; Karelin, A V; Koldashov, S V; Koldobskiy, S A; Krutkov, S Y; Kvashnin, A N; Leonov, A; Malakhov, V; Marcelli, L; Martucci, M; Mayorov, A G; Menn, W; Merge', M; Mikhailov, V V; Mocchiutti, E; Monaco, A; Mori, N; Munini, R; Osteria, G; Palma, F; Papini, P; Pearce, M; Picozza, P; Pizzolotto, C; Ricci, M; Ricciarini, S B; Rossetto, L; Sarkar, R; Scotti, V; Simon, M; Sparvoli, R; Spillantini, P; Stochaj, S J; Stockton, J C; Stozhkov, Y I; Vacchi, A; Vannuccini, E; Vasilyev, G I; Voronov, S A; Yurkin, Y T; Zampa, G; Zampa, N; Zverev, V G

    2013-01-01

    Precision measurements of the positron component in the cosmic radiation provide important information about the propagation of cosmic rays and the nature of particle sources in our Galaxy. The satellite-borne experiment PAMELA has been used to make a new measurement of the cosmic-ray positron flux and fraction that extends previously published measurements up to 300 GeV in kinetic energy. The combined measurements of the cosmic-ray positron energy spectrum and fraction provide a unique tool to constrain interpretation models. During the recent solar minimum activity period from July 2006 to December 2009 approximately 24500 positrons were observed. The results cannot be easily reconciled with purely secondary production and additional sources of either astrophysical or exotic origin may be required.

  19. Positron annihilation studies of moisture in graphite-reinforced composites

    NASA Technical Reports Server (NTRS)

    Singh, J. J.; Holt, W. H.; Mock, W., Jr.; Buckingham, R. D.

    1980-01-01

    The positron lifetime technique of monitoring absorbed moisture is applied to several composites, including graphite/polymides which are candidates for high-temperature (over 260 C) applications. The experimental setup is a conventional fast-slow coincidence system wherein the positron lifetime is measured with respect to a reference time determined by the detection of a nuclear gamma ray emitted simultaneously with the positron. From the experiments, a rate of change of positron mean lifetime per unit mass of water can be determined for each type of specimen. Positron lifetime spectra are presented for a graphite/polyimide composite and for a pure polyimide.

  20. Cosmic Ray Positrons at High Energies: A New Measurement

    E-print Network

    HEAT Collaboration

    1995-05-30

    We present a new measurement of the cosmic-ray positron fraction e+/(e+ + e-) obtained from the first balloon flight of the High Energy Antimatter Telescope (HEAT). Using a magnet spectrometer combined with a transition radiation detector, an electromagnetic calorimeter, and time-of-flight counters we have achieved a high degree of background rejection. Our results do not indicate a major contribution to the positron flux from primary sources. In particular, we see no evidence for the significant rise in the positron fraction at energies above ~10 GeV previously reported.

  1. Lifetime Measurements and Deformation in ^79Sr

    NASA Astrophysics Data System (ADS)

    Ryu, Y. K.; Kaye, R. A.; Arora, S. R.; Tabor, S. L.; Baldwin, T.; Campbell, D. B.; Chandler, C.; Cooper, M. W.; Hoffman, C. R.; Pavan, J.; Wiedeking, M.; D"Oring, J.; Sun, Y.; Gerbick, S. M.; Grubor-Urosevic, O.; Riley, L. A.

    2006-10-01

    High-spin states in ^79Sr were produced following the ^54Fe(^28Si, 2pn) fusion-evaporation reaction using a beam energy of 90 MeV at the Florida State University (FSU) Tandem-Linac facility, and the resulting de-exciting ? rays were detected with the FSU Ge array of 10 Compton-suppressed detectors. The ^54Fe target was thick enough so that all of the synthesized nuclei could stop completely in the target, resulting in Doppler-shifted ?-ray line shapes that could be analyzed using the Doppler-shift attenuation method. In all, 23 lifetimes were measured in three separate band structures using this method, and then used to infer transition quadrupole moments (Qt) and quadrupole deformations (?2) using the rotational model. The results show good qualitative agreement with the predictions of both cranked Woods-Saxon (CWS) and projected shell model (PSM) calculations. The band based on a d5/2 single-particle orbit, verified in this study through ?- ? coincidences, intensity measurements, and directional correlation of oriented nuclei (DCO) ratios, was found to have the largest average deformation (?2,ave = 0.41) among the three bands, in agreement with the CWS and PSM predictions.

  2. Lifetime Measurements and Deformation in ^79Sr

    NASA Astrophysics Data System (ADS)

    Ryu, Y. K.; Kaye, R. A.; Arora, S. R.; Tabor, S. L.; Baldwin, T.; Campbell, D. B.; Chandler, C.; Cooper, M. W.; Hoffman, C. R.; Pavan, J.; Wiedeking, M.; D"Oring, J.; Sun, Y.; Gerbick, S. M.; Grubor-Urosevic, O.; Riley, L. A.

    2006-10-01

    High-spin states in ^79Sr were produced following the ^54Fe(^28Si, 2pn) fusion-evaporation reaction using a beam energy of 90 MeV at the Florida State University (FSU) Tandem-Linac facility, and the resulting de-exciting ? rays were detected with the FSU Ge array of 10 Compton-suppressed detectors. The ^54Fe target was thick enough so that all of the synthesized nuclei could stop completely in the target, resulting in Doppler-shifted ?-ray line shapes that could be analyzed using the Doppler-shift attenuation method. In all, 23 lifetimes were measured in three separate band structures using this method, and then used to infer transition quadrupole moments (Qt) and quadrupole deformations (?2) using the rotational model. The results show good qualitative agreement with the predictions of both cranked Woods-Saxon (CWS) and projected shell model (PSM) calculations. The band based on a d5/2 single-particle orbit, verified in this study through ?- ? coincidences, intensity measurements, and directional correlation of oriented nuclei (DCO) ratios, was found to have the largest average deformation (?2,ave= 0.41) among the three bands, in agreement with the CWS and PSM predictions. Supported in part by the NSF and the OWU SSRP.

  3. Positron energy-loss measurements in thin alumina films

    SciTech Connect

    Lynn, K.G.; Frieze, W.; Fischer, D.A.

    1982-01-01

    Transmitted-positron energy loss measurements were performed on approximately 100A alumina films with incident positron energies ranging from 0.5 to 3.0 keV. The positrons were electrostatically focussed on the film and the transmitted positrons were energy analyzed using a four-grid retarding field analyzer coupled with a two-stage channel electron multiplier plate connected with a phosphor screen. A strong transmitted elastic peak as well as indications of discrete energy losses were detected in these measurements. The observed discrete loss effects occurred at an average energy of approx. 25 eV and possibly approx. 50 eV. These findings are consistent with reported electron loss peaks due to plasmon excitation in alumina films.

  4. Metallic scattering lifetime measurements with terahertz time-domain spectroscopy

    NASA Astrophysics Data System (ADS)

    Lea, Graham Bryce

    The momentum scattering lifetime is a fundamental parameter of metallic conduction that can be measured with terahertz time-domain spectroscopy. This technique has an important strength over optical reflectance spectroscopy: it is capable of measuring both the phase and the amplitude of the probing radiation. This allows simultaneous, independent measurements of the scattering lifetime and resistivity. Broadly, it is the precision of the phase measurement that determines the precision of scattering lifetime measurements. This thesis describes milliradian-level phase measurement refinements in the experimental technique and measures the conductivity anisotropy in the correlated electron system CaRuO3. These phase measurement refinements translate to femtosecond-level refinements in scattering lifetime measurements of thin metallic films. Keywords: terahertz time-domain spectroscopy, calcium ruthenate, ruthenium oxides, correlated electrons, experimental technique.

  5. Application of positron annihilation lifetime spectroscopy (PALS) to study the nanostructure in amphiphile self-assembly materials: phytantriol cubosomes and hexosomes.

    PubMed

    Dong, Aurelia W; Fong, Celesta; Waddington, Lynne J; Hill, Anita J; Boyd, Ben J; Drummond, Calum J

    2015-01-21

    Self-assembled amphiphile nanostructures of colloidal dimensions such as cubosomes and hexosomes are of interest as delivery vectors in pharmaceutical and nanomedicine applications. Translation would be assisted through a better of understanding of the effects of drug loading on the internal nanostructure, and the relationship between this nanostructure and drug release profile. Positron annihilation lifetime spectroscopy (PALS) is sensitive to local microviscosity and is used as an in situ molecular probe to examine the Q2 (cubosome) ? H2 (hexosome) ? L2 phase transitions of the pharmaceutically relevant phytantriol-water system in the presence of a model hydrophobic drug, vitamin E acetate (VitEA). It is shown that the ortho-positronium lifetime (?) is sensitive to molecular packing and mobility and this has been correlated with the rheological properties of individual lyotropic liquid crystalline mesophases. Characteristic PALS lifetimes for L2 (?4? 4 ns) ? H2 (?4? 4 ns) > Q(2?Pn3m) (?4? 2.2 ns) are observed for the phytantriol-water system, with the addition of VitEA yielding a gradual increase in ? from ?? 2.2 ns for cubosomes to ?? 3.5 ns for hexosomes. The dynamic chain packing at higher temperatures and in the L2 and H2 phases is qualitatively less "viscous", consistent with rheological measurements. This information offers increased understanding of the relationship between internal nanostructure and species permeability. PMID:25459998

  6. Measurement of carrier generation lifetime in SOI devices Hyungcheol Shina,

    E-print Network

    Schroder, Dieter K.

    presents a new, simple method of measuring the generation lifetime in SOI (silicon-on-insulator) MOSFETS this technique, generation lifetime was mapped across ®nished SIMOX (separation by implantated oxygen) wafers to the ¯oating-body nature of the device (Fig. 2) [7±10]. The drain current is suppressed immediately after

  7. A measurement of the lifetime of the tau lepton

    Microsoft Academic Search

    P. Abreu; W. Adam; F. Adami; T. Adye; T. Akesson; G. D. Alekseev; P. Allen; S. Almehed; S. J. Alvsvaag; Ugo Amaldi; E G Anassontzis; P. Antilogus; W.-D. Apel; R.-J. Apsimon; B. Åsman; Pierre Astier; J.-E. Augustin; A. Augustinus; Paul Baillon; P. Bambade; F. Barao; Guido Barbiellini; Dimitri Yuri Bardin; A. Baroncelli; O. Barring; Walter Bartl; Marco Battaglia; M. J. Bates; M. Baubillier; K.-H. Becks; C. J. Beeston; M. Begalli; P. Beilliere; Yu A Belokopytov; P. Beltran; D. Benedic; J. M. Benlloch; M. Berggren; D. Bertrand; F. Bianchi; J. H. Bibby; M. S. Bilenky; P. Billoir; J. Bjarne; D. Bloch; S. Blyth; P. N. Bogolubov; T. Bolognese; M. Bonapart; M. Bonesini; W. Bonivento; P. S. L. Booth; M. Boratav; P. Borgeaud; G. Borisov; H. Borner; C. Bosio; B. Bostjancic; O. Botner; B. Bouquet; M. Bozzo; S. Braibant; P. Branchini; K. D. Brand; R. A. Brenner; C. Bricman; R. C. A. Brown; N. Brummer; J.-M. Brunet; L. Bugge; T. Buran; H. Burmeister; J. A. M. A. Buytaert; M. Caccia; M. Calvi; A. J. Camacho Rozas; J.-E. Campagne; A. Campion; T. Camporesi; V. Canale; F. Cao; F. Carena; L. Carroll; Carlo Caso; Edoardo Castelli; M. V. Castillo Gimenez; A. Cattai; F. R. Cavallo; L. Cerrito; A. Chan; P. Charpentier; P. Checchia; G. A. Chelkov; L. Chevalier; P V Chliapnikov; V. Chorowicz; R. Cirio; M. P. Clara; P. Collins; J. L. Contreras; R. Contri; G. Cosme; F. Couchot; H. B. Crawley; D J Crennell; G. Crosetti; N. Crosland; M. Crozon; J. Cuevas Maestro; S. Czellar; S. Dagoret; Erik Dahl-Jensen; B. Dalmagne; M. Dam; G. Damgaard; G. Darbo; Evelyne Daubie; P. D. Dauncey; Martyn Davenport; P. David; A. de Angelis; M. de Beer; H. de Boeck; Wim de Boer; C. de Clercq; M. D. M. de Fez Laso; N. de Groot; C. de La Vaissiere; B. de Lotto; A. de Min; C. Defoix; D. Delikaris; S. Delorme; P A Delpierre; N. Demaria; J E Derkaoui; Lucia Di Ciaccio; H. Dijkstra; F. Djama; J. Dolbeau; M. Donszelmann; K. Doroba; M. Dracos; J. Drees; M. Dris; Y. Dufour; W. Dulinski; L.-O. Eek; Paule Anna Mari Eerola; T J C Ekelöf; Gösta Ekspong; A. Elliot Peisert; J.-P. Engel; V P Falaleev; D. Fassouliotis; M. Fernandez Alonso; A. Ferrer; T. A. Filippas; A. Firestone; H. Foeth; E. Fokitis; P. Folegati; F. Fontanelli; K. A. J. Forbes; H. Forsbach; B J Franek; P. Frenkiel; D E C Fries; A. G. Frodesen; R. Fruhwirth; F. Fulda-Quenzer; K. Furnival; H. Furstenau; J A Fuster; J. M. Gago; G. Galeazzi; D. Gamba; C. Garcia; J. Garcia; U. Gasparini; P. Gavillet; E. N. Gazos; J.-P. Gerber; P. Giacomelli; K.-W. Glitza; R. Gokieli; V. M. Golovatyuk; J. J. Gomez Y Cadenas; A. Goobar; Gian P Gopal; M. Gorski; Valerio Gracco; A. Grant; F. Grard; E. Graziani; M.-H. Gros; G. Grosdidier; E. Gross; B. Grossetete; S A Gumenyuk; J. Guy; F. Hahn; M. Hahn; S. Haider; Z. Hajduk; A. Hakansson; A. Hallgren; K. Hamacher; G. Hamel de Monchenault; F. J. Harris; B. W. Heck; T. Henkes; I. Herbst; J. J. Hernandez; P. Herquet; H. Herr; I. Hietanen; C. O. Higgins; E. Higon; H. J. Hilke; S. D. Hodgson; T. Hofmokl; R. Holmes; S.-O. Holmgren; D. Holthuizen; P. F. Honore; J. E. Hooper; R. Horisberger; M. Houlden; J. Hrubec; P. O. Hulth; K. Hultqvist; D. Husson; B. D. Hyams; P. Ioannou; D. Isenhower; P.-S. Iversen; J. N. Jackson; P. Jalocha; G. Jarlskog; P. Jarry; B. Jean-Marie; E. K. Johansson; D. Johnson; M. Jonker; L. Jonsson; P. Juillot; G. Kalkanis; G Kantardjian; F. Kapusta; S. Katsanevas; E. C. Katsoufis; R. Keranen; J. Kesteman; B. A. Khomenko; N. N. Khovanski; B. King; N. J. Kjaer; H. Klein; W. Klempt; A. Klovning; P. Kluit; J. H. Koehne; B. Koene; P. Kokkinias; M Koratzinos; M. Koratzinos; K. Korcyl; A. V. Korytov; B. Korzen; V. Kostukhin; C. Kourkoumelis; T. Kreuzberger; J. Krolikowski; U. Kruener-Marquis; W. Krupinski; W. Kucewicz; K. Kurvinen; C Lambropoulos; J. W. Lamsa; L. Lanceri; V. Lapin; J.-P. Laugier; R. Lauhakangas; G. Leder; F. Ledroit; J. Lemonne; G. Lenzen; V. Lepeltier; A. Letessier-Selvon; D. Liko; E Lillethun; J. Lindgren; A. Lipniacka; I. Lippi; R. Llosa; B. Loerstad; M. Lokajicek; J. G. Loken; M. A. Lopez Aguera; A. Lopez-Fernandez; M. Los; D. Loukas; A. Lounis; J. J. Lozano; R. Lucock; P. Lutz; L. Lyons; G. Maehlum; J. Maillard; A. Maltezos; S. Maltezos; F. Mandl; J. Marco; M. Margoni; J.-C. Marin; A. Markou; S. Marti; L. Mathis; F. Matorras; C. Matteuzzi; G. Matthiae; M Mazzucato; M. Mc Cubbin; R. Mc Nulty; E. Menichetti; G. Meola; C. Meroni; W. T. Meyer; M. Michelotto; W. A. Mitaroff; G. V. Mitselmakher; U. Mjoernmark; T. Moa; R. Moeller; K. Moenig; M. R. Monge; P. Morettini; H. Mueller; H. Muller; W. J. Murray; G. Myatt; F. Naraghi; U. Nau-Korzen; F. L. Navarria; P. Negri; B. S. Nielsen; B. Nijjhar; V. Nikolaenko; V. Obraztsov; A. G. Olshevski; R. Orava; A. Ostankov; A. Ouraou; R. Pain; H. Palka; T. Papadopoulou; L. Pape; A. Passeri; M. Pegoraro; V. Perevozchikov; M. Pernicka; A. Perrotta

    1991-01-01

    The lifetime of the tau lepton has been measured by two independent methods using a silicon microvertex detector installed in the DELPHI detector. The signed impact parameter distribution of the one prong decays yielded a lifetime of tautau = 321 +\\/- 36 (stat.) +\\/- 16 (syst.) fs, while the decay length distribution of three prong decays gave the result tautau

  8. Precise measurements of the D0 and D+ meson lifetimes

    NASA Astrophysics Data System (ADS)

    Frabetti, P. L.; Cheung, H. W. K.; Cumalat, J. P.; Dallapiccola, C.; Ginkel, J. F.; Greene, S. V.; Johns, W. E.; Nehring, M. S.; Butler, J. N.; Cihangir, S.; Gaines, I.; Garbincius, P. H.; Garren, L.; Gourlay, S. A.; Harding, D. J.; Kasper, P.; Kreymer, A.; Lebrun, P.; Shukla, S.; Vittone, M.; Bianco, S.; Fabbri, F. L.; Sarwar, S.; Zallo, A.; Culbertson, R.; Gardner, R. W.; Greene, R.; Wiss, J.; Alimonti, G.; Bellini, G.; Caccianiga, B.; Cinquini, L.; Di Corato, M.; Giammarchi, M.; Inzani, P.; Leveraro, F.; Malvezzi, S.; Menasce, D.; Meroni, E.; Moroni, L.; Pedrini, D.; Perasso, L.; Sala, A.; Sala, S.; Torretta, D.; Buchholz, D.; Claes, D.; Gobbi, B.; O'Reilly, B.; Bishop, J. M.; Cason, N. M.; Kennedy, C. J.; Kim, G. N.; Lin, T. F.; Pušelji?, D. L.; Ruchti, R. C.; Shephard, W. D.; Swiatek, J. A.; Wu, Z. Y.; Arena, V.; Boca, G.; Castoldi, C.; Gianini, G.; Ratti, S. P.; Riccardi, C.; Vitulo, P.; Lopez, A.; Grim, G. P.; Paolone, V. S.; Yager, P. M.; Wilson, J. R.; Sheldon, P. D.; Davenport, F.; Filaseta, J. F.; Blackett, G. R.; Pisharody, M.; Handler, T.; Cheon, B. G.; Kang, J. S.; Kim, K. Y.; E687 Collaboration

    1994-03-01

    We report precise measurements of the D0 and D+ meson lifetimes by the E687 Collaboration at Fermilab. The measurements have been made using 16000 fully reconstructed decays of the D0 into the K-?+ and K-?+?-?+ final states and 9000 decays of the D+ into the K-?+?+ final state. The lifetimes of the D0 and D+ mesons are measured to be 0.413±0.004±0.003 ps and 1.048±0.015±01011 ps respectively.

  9. A new measurement of the lifetime of the ?c+

    NASA Astrophysics Data System (ADS)

    E687 Collaboration; Frabetti, P. L.; Cheung, H. W. K.; Cumalat, J. P.; Dallapiccola, C.; Ginkel, J. F.; Johns, W. E.; Nehring, M. S.; Vaandering, E. W.; Butler, J. N.; Cihangir, S.; Gaines, I.; Garbincius, P. H.; Garren, L.; Gourlay, S. A.; Harding, D. J.; Kasper, P.; Kreymer, A.; Lebrun, P.; Shukla, S.; Vittone, M.; Bianco, S.; Fabbri, F. L.; Sarwar, S.; Zallo, A.; Cawlfield, C.; Culbertson, R.; Gardner, R. W.; Gottschalk, E.; Greene, R.; Park, K.; Rahimi, A.; Wiss, J.; Alimonti, G.; Bellini, G.; Boschini, M.; Brambilla, D.; Caccianiga, B.; Cinquini, L.; di Corato, M.; Dini, P.; Giammarchi, M.; Inzani, P.; Leveraro, F.; Malvezzi, S.; Menasce, D.; Meroni, E.; Milazzo, L.; Moroni, L.; Pedrini, D.; Perasso, L.; Prelz, F.; Sala, A.; Sala, S.; Torretta, D.; Buchholz, D.; Claes, D.; Gobbi, B.; O'Reilly, B.; Bishop, J. M.; Cason, N. M.; Kennedy, C. J.; Kim, G. N.; Lin, T. F.; Puseljic, D. L.; Ruchti, R. C.; Shephard, W. D.; Swiatek, J. A.; Wu, Z. Y.; Arena, V.; Boca, G.; Bonomi, G.; Castoldi, C.; Gianini, G.; Merlo, M.; Ratti, S. P.; Riccardi, C.; Viola, L.; Vitulo, P.; Lopez, A.; Mendez, L.; Mirles, A.; Montiel, E.; Olaya, D.; Ramirez, E.; Rivera, C.; Zhang, Y.; Link, J. M.; Paolone, V. S.; Yager, P. M.; Wilson, J. R.; Cao, J.; Hosack, M.; Sheldon, P. D.; Davenport, F.; Cho, K.; Danyo, K.; Handler, T.; Cheon, B. G.; Chung, Y. S.; Kang, J. S.; Kim, K. Y.; Lee, K. B.; Myung, S. S.

    1998-05-01

    New measurements of the lifetime and mass of the ?c+ are presented. The ?c+ has been reconstructed through the two decay channels ?-?+?+ and ?+K-?+. The data were accumulated by the Fermilab high energy photoproduction experiment E687. The lifetime is measured to be 0.34+0.07-0.05 (stat.)+/-0.02 (syst.) ps while the mass is measured to be 2465.8+/-1.9 (stat.)+/-2.5 (syst.) MeV/c2.

  10. Neutron lifetime measurements using gravitationally trapped ultracold neutrons

    E-print Network

    A. P. Serebrov; V. E. Varlamov; A. G. Kharitonov; A. K. Fomin; Yu. N. Pokotilovski; P. Geltenbort; I. A. Krasnoschekova; M. S. Lasakov; R. R. Taldaev; A. V. Vassiljev; O. M. Zherebtsov

    2009-02-02

    Our experiment using gravitationally trapped ultracold neutrons (UCN) to measure the neutron lifetime is reviewed. Ultracold neutrons were trapped in a material bottle covered with perfluoropolyether. The neutron lifetime was deduced from comparison of UCN losses in the traps with different surface-to-volume ratios. The precise value of the neutron lifetime is of fundamental importance to particle physics and cosmology. In this experiment, the UCN storage time is brought closer to the neutron lifetime than in any experiments before:the probability of UCN losses from the trap was only 1% of that for neutron beta decay. The neutron lifetime obtained,878.5+/-0.7stat+/-0.3sys s, is the most accurate experimental measurement to date.

  11. A new method for carrier lifetime measurements in PIN diodes

    NASA Astrophysics Data System (ADS)

    Szcz?sny, Juliusz; Jele?ski, Andrzej

    1989-02-01

    Several existing methods of carrier lifetime measurements in PIN diodes give an effective carrier lifetime which depends on the measurement conditions. In this paper a new method for measurements of the carrier lifetime in the diode base region is presented. This method is based on the measurement of rapid changes of the voltage drop across a PIN diode, when successive rectangular pulses are applied to the diode under the condition that the diffusion current to end regions is negligibly small. However, contrary to the double-pulse method the voltage drop across heavily doped regions, ohmic contacts and the diode leakage are taken into account. Measured carrier lifetimes in BA379 diodes produced by different manufacturers are also given.

  12. High Efficiency Positron Accumulation for High-Precision Measurements

    E-print Network

    Hoogerheide, S Fogwell; Novitski, E; Gabrielse, G

    2015-01-01

    Positrons are accumulated within a Penning trap designed to make more precise measurements of the positron and electron magnetic moments. The retractable radioactive source used is weak enough to require no license for handling radioactive material and the radiation dosage one meter from the source gives an exposure several times smaller than the average radiation dose on the earth's surface. The 100 mK trap is mechanically aligned with the 4.2 K superconducting solenoid that produces a 6 tesla magnetic trapping field with a direct mechanical coupling.

  13. Nuclear Instruments and Methods in Physics Research. Section B; Microstructural Characterization of Semi-Interpenetrating Polymer Networks by Positron Lifetime Spectroscopy

    NASA Technical Reports Server (NTRS)

    Singh, Jag J.; Pater, Ruth H.; Eftekhari, Abe

    1998-01-01

    Thermoset and thermoplastic polyimides have complementary physical/mechanical properties. Whereas thermoset polyimides are brittle and generally easier to process, thermoplastic polyimides are tough but harder to process. It is expected that a combination of these two types of polyimides may help produce polymers more suitable for aerospace applications. Semi-Interpenetrating Polymer Networks (S-IPNs) of thermoset LaRC(Trademark)-RP46 and thermoplastic LARC(Trademark)-IA polyimides were prepared in weight percent ratios ranging from 100:0 to 0: 100. Positron lifetime measurements were made in these samples to correlate their free volume features with physical/mechanical properties. As expected, positronium atoms are not formed in these samples. The second life time component has been used to infer the positron trap dimensions. The "free volume" goes through a minimum at about 50:50 ratio, suggesting that S-IPN samples are not merely solid solutions of the two polymers. These data and related structural properties of the S-IPN samples have been discussed in this paper.

  14. A preliminary, precise measurement of the average B hadron lifetime

    SciTech Connect

    SLD Collaboration

    1994-07-01

    The average B hadron lifetime was measured using data collected with the SLD detector at the SLC in 1993. From a sample of {approximately}50,000 Z{sup 0} events, a sample enriched in Z{sup 0} {yields} b{bar b} was selected by applying an impact parameter tag. The lifetime was extracted from the decay length distribution of inclusive vertices reconstructed in three dimensions. A binned maximum likelihood method yielded an average B hadron lifetime of {tau}{sub B} = 1.577 {plus_minus} 0.032(stat.) {plus_minus} 0.046(syst.) ps.

  15. Precision measurement of the ?b(0) baryon lifetime.

    PubMed

    Aaij, R; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; Anderlini, L; Anderson, J; Andreassen, R; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Baesso, C; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bauer, Th; Bay, A; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Burducea, I; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carranza-Mejia, H; Carson, L; Carvalho Akiba, K; Casse, G; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cenci, R; Charles, M; Charpentier, Ph; Chen, P; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Couturier, B; Cowan, G A; Craik, D C; Cunliffe, S; Currie, R; D'Ambrosio, C; David, P; David, P N Y; Davis, A; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Dogaru, M; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Falabella, A; Färber, C; Fardell, G; Farinelli, C; Farry, S; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furcas, S; Furfaro, E; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garofoli, J; Garosi, P; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gorbounov, P; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hartmann, T; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicheur, A; Hicks, E; Hill, D; Hoballah, M; Hombach, C; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Hussain, N; Hutchcroft, D; Hynds, D; Iakovenko, V; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jans, E; Jaton, P; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Kaballo, M; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Kenyon, I R; Ketel, T; Keune, A; Khanji, B; Kochebina, O; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucharczyk, M; Kudryavtsev, V; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Li Gioi, L; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; Lohn, S; Longstaff, I; Lopes, J H; Lopez-March, N; Lu, H; Lucchesi, D; Luisier, J; Luo, H; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Manca, G; Mancinelli, G; Maratas, J; Marconi, U; Marino, P; Märki, R; Marks, J; Martellotti, G; Martens, A; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martins Tostes, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Maurice, E; Mazurov, A; Mc Skelly, B; McCarthy, J; McNab, A; McNulty, R; Meadows, B; Meier, F; Meissner, M; Merk, M; Milanes, D A; Minard, M-N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Mordà, A; Morello, M J; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I

    2013-09-01

    The ratio of the ?b(0) baryon lifetime to that of the B(0) meson is measured using 1.0??fb(-1) of integrated luminosity in 7 TeV center-of-mass energy pp collisions at the LHC. The ?b(0) baryon is observed for the first time in the decay mode ?b(0)?J/?pK-, while the B(0) meson decay used is the well known B(0)?J/??+ K- mode, where the ?+ K- mass is consistent with that of the K(*0)(892) meson. The ratio of lifetimes is measured to be 0.976±0.012±0.006, in agreement with theoretical expectations based on the heavy quark expansion. Using previous determinations of the B(0) meson lifetime, the ?b(0) lifetime is found to be 1.482±0.018±0.012??ps. In both cases, the first uncertainty is statistical and the second systematic. PMID:25166658

  16. A measurement of the average bottom hadron lifetime

    Microsoft Academic Search

    Gideon Alexander; J Allison; N Altekamp; K A Ametewee; K J Anderson; S. Anderson; S. Arcelli; S. Asai; D A Axen; Georges Azuelos; A H Ball; E Barberio; R J Barlow; R Bartoldus; J Richard Batley; J Bechtluft; C Beeston; T Behnke; A N Bell; K W Bell; G Bella; Stanislaus Cornelius Maria Bentvelsen; P Berlich; Siegfried Bethke; O Biebel; Volker Blobel; Ian J Bloodworth; J E Bloomer; M Bobinski; P Bock; H M Bosch; M Boutemeur; B T Bouwens; S Braibant; R M Brown; Helfried J Burckhart; C Burgard; R Bürgin; P Capiluppi; R K Carnegie; A A Carter; J R Carter; C Y Chang; D G Charlton; D Chrisman; P E L Clarke; I Cohen; J E Conboy; O C Cooke; M Cuffiani; S Dado; C Dallapiccola; G M Dallavalle; S De Jong; L A del Pozo; Klaus Desch; M S Dixit; E do Couto e Silva; M Doucet; E Duchovni; G Duckeck; I P Duerdoth; J E G Edwards; P G Estabrooks; H G Evans; M Evans; Franco Luigi Fabbri; P Fath; F Fiedler; M Fierro; H M Fischer; R Folman; D G Fong; M Foucher; A Fürtjes; P Gagnon; A Gaidot; J W Gary; J Gascon; S M Gascon-Shotkin; N I Geddes; C Geich-Gimbel; F X Gentit; T Geralis; G Giacomelli; P Giacomelli; R Giacomelli; V Gibson; W R Gibson; D M Gingrich; D A Glenzinski; J Goldberg; M J Goodrick; W Gorn; C Grandi; E Gross; Jacob Grunhaus; M Gruwé; C Hajdu; G G Hanson; M Hansroul; M Hapke; C K Hargrove; P A Hart; C Hartmann; M Hauschild; C M Hawkes; R Hawkings; Richard J Hemingway; M Herndon; G Herten; R D Heuer; M D Hildreth; J C Hill; S J Hillier; T Hilse; P R Hobson; R James Homer; A K Honma; D Horváth; R Howard; R E Hughes-Jones; D E Hutchcroft; P Igo-Kemenes; D C Imrie; M R Ingram; K Ishii; A Jawahery; P W Jeffreys; H Jeremie; Martin Paul Jimack; A Joly; C R Jones; G Jones; M Jones; R W L Jones; U Jost; P Jovanovic; T R Junk; D A Karlen; K Kawagoe; T Kawamoto; Richard K Keeler; R G Kellogg; B W Kennedy; B J King; J Kirk; S Kluth; T Kobayashi; M Kobel; D S Koetke; T P Kokott; M Kolrep; S Komamiya; T Kress; P Krieger; J Von Krogh; P Kyberd; G D Lafferty; H Lafoux; R Lahmann; W P Lai; D Lanske; J Lauber; S R Lautenschlager; J G Layter; D Lazic; A M Lee; E Lefebvre; Daniel Lellouch; J Letts; L Levinson; C Lewis; S L Lloyd; F K Loebinger; G D Long; Michael J Losty; J Ludwig; A Malik; M Mannelli; S Marcellini; C Markus; A J Martin; J P Martin; G Martínez; T Mashimo; W Matthews; P Mättig; W J McDonald; J A McKenna; E A McKigney; T J McMahon; A I McNab; R A McPherson; F Meijers; S Menke; F S Merritt; H Mes; J Meyer; Aldo Michelini; G Mikenberg; D J Miller; R Mir; W Mohr; A Montanari; T Mori; M Morii; U Müller; K Nagai; I Nakamura; H A Neal; B Nellen; B Nijjhar; R Nisius; S W O'Neale; F G Oakham; F Odorici; H O Ögren; N J Oldershaw; T Omori; M J Oreglia; S Orito; J Pálinkás; G Pásztor; J R Pater; G N Patrick; J Patt; M J Pearce; S Petzold; P Pfeifenschneider; J E Pilcher; J L Pinfold; D E Plane; P R Poffenberger; B Poli; A Posthaus; H Przysiezniak; D L Rees; D Rigby; S Robertson; S A Robins; N L Rodning; J M Roney; A M Rooke; E Ros; A M Rossi; M Rosvick; P Routenburg; Y Rozen; K Runge; O Runólfsson; U Ruppel; D R Rust; R Rylko; K Sachs; E Sarkisyan-Grinbaum; M Sasaki; C Sbarra; A D Schaile; O Schaile; F Scharf; P Scharff-Hansen; P Schenk; B Schmitt; S Schmitt; M Schröder; H C Schultz-Coulon; M Schulz; M Schumacher; P Schütz; W G Scott; T G Shears; B C Shen; C H Shepherd-Themistocleous; P Sherwood; G P Siroli; A Sittler; A Skillman; A Skuja; A M Smith; T J Smith; G A Snow; Randall J Sobie; S Söldner-Rembold; R W Springer; M Sproston; A Stahl; M Steiert; K Stephens; J Steuerer; B Stockhausen; D Strom; F Strumia; P Szymanski; R Tafirout; S D Talbot; S Tanaka; P Taras; S Tarem; M Thiergen; M A Thomson; E Von Törne; S Towers; I Trigger; T Tsukamoto; E Tsur; A S Turcot; M F Turner-Watson; P Utzat; R Van Kooten; G Vasseur; M Verzocchi; P Vikas; M G Vincter; E H Vokurka; F Wäckerle; A Wagner; C P Ward; D R Ward; J J Ward; P M Watkins; A T Watson; N K Watson; P S Wells; N Wermes; J S White; B Wilkens; G W Wilson; J A Wilson; G Wolf; S A Wotton; T R Wyatt; S Yamashita; G Yekutieli; V Zacek

    1997-01-01

    The average b hadron lifetime, $\\\\tau_{{\\\\rm b}}$, has been measured using approximately 3.5 million hadronic events collected with the OPAL detector at LEP between 1991 and 1994. A lifetime tag based on a neural network algorithm was used to select ${\\\\rm Z}^0\\\\rightarrow {\\\\rm b\\\\bar b}$ events. A secondary vertex reconstructed on the opposite side from the b-tag was used to

  17. Direct Measurements of the Lifetime of Heavy Hypernuclei

    E-print Network

    X. Qiu; L. Tang; A. Margaryan; P. Achenbach; A. Ahmidouch; I. Albayrak; D. Androic; A. Asaturyan; R. Asaturyan; O. Ates; R. Badui; P. Baturin; W. Boeglin; J. Bono; E. Brash; P. Carter; C. Chen; X. Chen; A. Chiba; E. Christy; M. M. Dalton; S. Danagoulian; R. De Leo; D. Doi; M. Elaasar; R. Ent; H. Fenker; Y. Fujii; M. Furic; M. Gabrielyan; L. Gan; F. Garibaldi; D. Gaskell; A. Gasparian; T. Gogami; O. Hashimoto; T. Horn; B. Hu; E. V. Hungerford; M. Jones; H. Kanda; M. Kaneta; M. Kawai; D. Kawama; H. Khanal; M. Kohl; A. Liyanage; W. Luo; K. Maeda; P. Markowitz; T. Maruta; A. Matsumura; V. Maxwell; A. Mkrtchyan; H. Mkrtchyan; S. Nagao; S. N. Nakamura; A. Narayan; C. Neville; G. Niculescu; M. I. Niculescu; A. Nunez; Nuruzzaman; Y. Okayasu; T. Petkovic; J. Pochodzalla; J. Reinhold; V. M. Rodriguez; C. Samanta; B. Sawatzky; T. Seva; A. Shichijo; V. Tadevosyan; N. Taniya; K. Tsukada; M. Veilleux; W. Vulcan; F. R. Wesselmann; S. A. Wood; L. Ya; T. Yamamoto; Z. Ye; K. Yokota; L. Yuan; S. Zhamkochyan; L. Zhu

    2013-01-16

    The lifetime of a Lambda particle embedded in a nucleus (hypernucleus) decreases from that of free Lambda decay due to the opening of the Lambda N to NN weak decay channel. However, it is generally believed that the lifetime of a hypernucleus attains a constant value (saturation) for medium to heavy hypernuclear masses, yet this hypothesis has been difficult to verify. The present paper reports a direct measurement of the lifetime of medium-heavy hypernuclei produced with a photon-beam from Fe, Cu, Ag, and Bi targets. The recoiling hypernuclei were detected by a fission fragment detector using low-pressure multi-wire proportional chambers. The experiment agrees remarkably well with the only previously-measured single-species heavy-hypernucleus lifetime, that of Fe56_Lambda at KEK, and has significantly higher precision. The experiment disagrees with the measured lifetime of an unknown combination of heavy hypernuclei with 180lifetime decrease.

  18. Measuring the Neutron Lifetime with Magnetically Trapped Ultracold Neutrons

    NASA Astrophysics Data System (ADS)

    Mumm, H. P.; Huber, M. G.; Yue, A. T.; Thompson, A. K.; Dewey, M. S.; Huffer, C. R.; Huffman, P. R.; Schelhammer, K. W.; O'Shaughnessy, C.; Coakley, K. J.

    2014-03-01

    We describe an experiment to measure the neutron lifetime using a technique with a set of systematic uncertainties largely different than those of previous measurements. In this approach, ultracold neutrons (UCN) are produced by inelastic scattering of cold (0.89 nm) neutrons in a reservoir of superfluid 4He. These neutrons are then confined using a three-dimensional magnetic trap. As the trapped neutrons beta decay, the energetic electrons produced in the decay generate scintillations in the liquid He; each decay is detectable with nearly 100 % efficiency. The neutron lifetime can be directly determined by measuring the scintillation rate as a function of time.

  19. Measurement of the average lifetime of B hadrons

    Microsoft Academic Search

    P. Abreu; W. Adam; F. Adami; T. Adye; T. Akesson; G. D. Alekseev; P. Allen; S. Almehed; S. J. Alvsvaag; U. Amaldi; E. Anassontzis; P. Antilogus; W. D. Apel; R. J. Apsimon; B. Åsman; P. Astier; J. E. Augustin; A. Augustinus; P. Baillon; P. Bambade; F. Barao; R. Barate; G. Barbiellini; D. Y. Bardin; A. Baroncelli; O. Barring; W. Bartl; M. J. Bates; M. Bataglia; M. Baubillier; K. H. Becks; C. J. Beeston; M. Begalli; P. Beilliere; Yu. Belokopytov; P. Beltran; D. Benedic; J. M. Benlloch; M. Berggren; D. Bertrand; F. Bianchi; M. S. Bilenky; P. Billoir; J. Bjarne; D. Bloch; S. Blyth; V. Bocci; P. N. Bogolubov; T. Bolognese; M. Bonapart; M. Bonesini; W. Bonivento; P. S. L. Booth; M. Boratav; P. Borgeaud; G. Borisov; H. Borner; C. Bosio; B. Bostjancic; O. Botner; B. Bouquet; M. Bozzo; S. Braibant; P. Branchini; K. D. Brand; R. A. Brenner; C. Bricman; R. C. A. Brown; N. Brummer; J. M. Brunet; L. Bugge; T. Burran; H. Burmeister; J. A. M. A. Buytaert; M. Caccia; M. Calvi; A. J. Camacho Rozas; A. Campion; T. Camporesi; V. Canale; F. Cao; F. Carena; L. Carroll; C. Caso; E. Castelli; M. V. Castillo Gimenez; A. Cattai; F. R. Cavallo; L. Cerrito; A. Chan; P. Charpentier; P. Checchia; G. A. Chelkov; L. Chevalier; M. Chliapnikov; V. Chorowicz; R. Cirio; M. P. Clara; P. Collins; J. L. Contreras; R. Contri; G. Cosme; F. Couchot; H. B. Crawley; D. Crennell; G. Crosetti; M. Crozon; J. Cuevas Maestro; S. Czellar; S. Dagoret; E. Dahl-Jensen; B. Dalmagne; M. Dam; G. Damgaard; G. Darbo; E. Daubie; P. D. Dayncey; M. Davenport; P. David; A. De Angelis; M. De Beer; H. De Boeck; W. De Boer; C. De Clercq; M. D. M. De Fez Laso; N. De Groot; C. De Vaissiere; B. De Lotto; A. De Min; C. Defoix; D. Delikaris; S. Delorme; P. Delpierre; N. Demaria; L. Diciaccio; H. Dijkstra; F. Djama; J. Dolbeau; O. Doll; M. Donszelmann; K. Doraba; M. Dracos; J. Drees; M. Dris; Y. Dufour; W. Dulinski; L. O. Eek; P. A.-M. Eerola; T. Ekelof; G. Ekspong; A. Elliot Peisert; J. P. Engel; D. Fassouliotis; M. Feindt; A. Fenyuk; M. Fernandez Alonso; A. Ferrer; T. A. Filippas; A. Firestone; H. Foeth; E. Fokitis; P. Folegati; F. Fontanelli; K. A. J. Forbes; H. Forsbach; B. Franek; P. Frenkiel; D. C. Fries; A. G. Frodesen; R. Fruhwirth; F. Fulda-Quenzer; K. Furnival; H. Furstenau; J. Fuster; G. Galeazzi; D. Gamba; C. Garcia; J. Garcia; C. Gaspar; U. Gasparini; P. Gavillet; E. N. Gazis; J. P. Gerber; P. Giacomelli; K. W. Glitza; R. Gokieli; V. M. Golovatyuk; J. J. Gomez Y Cadenas; A. Goobar; G. Gopa; M. Gorski; V. Cracco; A. Grant; F. Grard; E. Graziani; M. H. Gros; G. Grosdidier; E. Gross; B. Grossetete; P. Grosse-Wiesmann; J. Guy; F. Hahn; M. Hahn; S. Haider; Z. Hajduk; A. Hakansson; A. Hallgren; K. Hamacher; G. Hamel De Monchenault; F. J. Harris; B. W. Heck; T. Henkes; I. Herbst; J. J. Hernandez; P. Herquet; H. Herr; I. Hietanen; C. O. Higgins; E. Higon; H. J. Hilke; S. D. Hodgson; T. Hofmokl; R. Holmes; S. O. Holmgren; D. Holthuizen; P. F. Honore; J. E. Hooper; M. Houlden; J. Hrubec; P. O. Hulth; K. Hultqvist; D. Husson; P. Ioannou; D. Isenhower; P. S. Iversen; J. N. Jackson; P. Jalocha; G. Jarlskog; P. Jarry; B. Jean-Marie; E. K. Johansson; D. Johnson; M. Jonker; L. Jonsson; P. Juillot; G. Kalkanis; G. Kalmus; F. Kapusta; S. Katsanevas; E. C. Katsoufis; R. Keranen; J. Kesteman; B. A. Khomenko; N. N. Khovanski; B. King; N. J. Kjaer; W. Klempt; A. Klovning; P. Kluit; A. Koch-Mehrin; J. H. Koehne; B. Koene; P. Kokkinas; M. Kopf; M. Koratzinos; K. Korcyl; A. V. Korytov; V. Kostukhin; C. Kourkoumelis; T. Kreuzberger; J. Krollkowski; I. Kronkvist; J. Krstic; U. Kruener-Marquis; W. Krupinski; W. Kucewicz; K. Kurvinen; C. Lacasta; C. Lambropoulos; J. W. Lamsa; L. Lanceri; V. Lapin; J. P. Laugier; R. Lauhakangas; G. Leder; F. Ledroit; R. Leitner; Y. Lemoigne; J. Lemonne; G. Lenzen; V. Lepeltier; A. Letessier-Selvon; D. Liko; E. Lieb; E. Lillethun; J. Lindgren; A. Lipniacka; I. Lippi; R. Llosa; B. Loerstad; M. Lokajicek; J. G. Loken; M. A. Lopez Aguera; A. Lopez-Fernandez; M. Los; D. Loukas; A. Lounis; J. J. Lozano; R. Lucock; P. Lutz; L. Lyons; G. Maehlum; N. Magnussen; J. Maillard; A. Maltezos; F. Mandl; J. Marco; M. Margoni; J. C. Marin; A. Markou; S. Marti; L. Mathis; F. Matorras; C. Matteuzzi; G. Matthiae; M. Matveev; M. Mazzucato; M. McCubbin; R. McKay; R. McNulty; E. Menichetti; C. Meroni; W. T. Meyer; M. Michelotto; W. A. Mitaroff; G. V. Mitselmakher; U. Mjoernmark; T. Moa; R. Moeller; K. Moenig; M. R. Monge; P. Morettini; H. Mueller; W. J. Murray; G. Myatt; F. Naraghi; U. Nau-Korzen; F. L. Navarria; P. Negri; B. S. Nielsen; B. Nijjhar; V. Nikolaenko; V. Obraztsov; A. G. Olshevski; R. Orava; A. Ostankov; A. Ouraou; M. Paganoni; R. Pain; H. Palka; T. Papadopoulou; L. Pape; A. Passeri; M. Pegoraro; V. Perevozchikov; M. Pernicka; A. Perrotta; F. Pierre; M. Pimenta; O. Pingot; M. E. Pol; G. Polok; P. Poropat

    1992-01-01

    The average lifetime ofB hadrons produced in hadronicZ0 decays has been measured with the DELPHI detector at LEP. The measurement is based on the analysis of the impact parameter distributions of highpt muons and hadrons. The resulting meanB lifetimes are tB=(1.30±0.10±0.08)ps and tB=(1.27±0.04±0.12)ps respectively, giving a combined value of tB=(1.28±0.10)ps. The hadronic sample was also used to measure the partialZ0

  20. Measurements of the electron-positron continuum in ALICE

    E-print Network

    Christoph Baumann; for the ALICE Collaboration

    2012-10-09

    The status of the analysis of electron-positron pairs measured by ALICE in pp collisions at $\\sqrt{s} = 7$ TeV and central Pb-Pb collisions at $\\sqrt{s_\\mathrm{NN}}=2.76$ TeV is presented. Key questions and the main challenges of the analysis are discussed on the basis of first raw invariant mass spectra for both collision systems.

  1. Measurement of the Positron Work Functions of Iron, Molybdenum, Titanium, and Vanadium

    Microsoft Academic Search

    Mohammed Mustafa Jibaly

    1987-01-01

    Measurements are reported of the positron work functions of submonolayer contaminated polycrystalline surfaces of copper, iron, molybdenum, titanium, and vanadium. The positron work functions varphi^+ were obtained by measuring the spectrum of slow positrons re-emitted by the metal surfaces when bombarded with KeV energy positrons. It is found that varphi _sp{rm Cu}{+} = -0.6 +\\/- 0.2 eV, varphi_sp{rm Mo}{+ }

  2. Measurement of the charged kaon lifetime with the KLOE detector

    NASA Astrophysics Data System (ADS)

    The KLOE collaboration; Ambrosino, F.; Antonelli, A.; Antonelli, M.; Archilli, F.; Bacci, C.; Beltrame, P.; Bencivenni, G.; Bertolucci, S.; Bini, C.; Bloise, C.; Bocchetta, S.; Bossi, F.; Branchini, P.; Caloi, R.; Campana, P.; Capon, G.; Capussela, T.; Ceradini, F.; Chi, S.; Chiefari, G.; Ciambrone, P.; De Lucia, E.; De Santis, A.; De Simone, P.; De Zorzi, G.; Denig, A.; Di Domenico, A.; Di Donato, C.; Di Micco, B.; Doria, A.; Dreucci, M.; Felici, G.; Ferrari, A.; Ferrer, M. L.; Fiore, S.; Forti, C.; Franzini, P.; Gatti, C.; Gauzzi, P.; Giovannella, S.; Gorini, E.; Graziani, E.; Kluge, W.; Kulikov, V.; Lacava, F.; Lanfranchi, G.; Lee-Franzini, J.; Leone, D.; Martini, M.; Massarotti, P.; Mei, W.; Meola, S.; Miscetti, S.; Moulson, M.; Müller, S.; Murtas, F.; Napolitano, M.; Nguyen, F.; Palutan, M.; Pasqualucci, E.; Passeri, A.; Patera, V.; Perfetto, F.; Primavera, M.; Santangelo, P.; Saracino, G.; Sciascia, B.; Sciubba, A.; Sibidanov, A.; Spadaro, T.; Testa, M.; Tortora, L.; Valente, P.; Venanzoni, G.; Versaci, R.; Xu, G.

    2008-01-01

    We have measured the charged kaon lifetime using a sample of 15 × 106 tagged kaon decays. Charged kaons were produced in pairs at the DA?NE phi-factory, e+e? ? phi ? K+K?. The decay of a K+ was tagged by the production of a K? and viceversa. The lifetime was obtained, for both charges, from independent measurements of the decay time and decay length distributions. From fits to the four distributions we find ? = (12.347±0.030) ns.

  3. Measurement of the charged kaon lifetime with the KLOE detector

    NASA Astrophysics Data System (ADS)

    KLOE Collaboration; Ambrosino, F.; Antonelli, A.; Antonelli, M.; Archilli, F.; Bacci, C.; Beltrame, P.; Bencivenni, G.; Bertolucci, S.; Bini, C.; Bloise, C.; Bocchetta, S.; Bossi, F.; Branchini, P.; Caloi, R.; Campana, P.; Capon, G.; Capussela, T.; Ceradini, F.; Chi, S.; Chiefari, G.; Ciambrone, P.; DeLucia, E.; DeSantis, A.; DeSimone, P.; DeZorzi, G.; Denig, A.; Di Domenico, A.; Di Donato, C.; Di Micco, B.; Doria, A.; Dreucci, M.; Felici, G.; Ferrari, A.; Ferrer, M. L.; Fiore, S.; Forti, C.; Franzini, P.; Gatti, C.; Gauzzi, P.; Giovannella, S.; Gorini, E.; Graziani, E.; Kluge, W.; Kulikov, V.; Lacava, F.; Lanfranchi, G.; Lee-Franzini, J.; Leone, D.; Martini, M.; Massarotti, P.; Mei, W.; Meola, S.; Miscetti, S.; Moulson, M.; Müller, S.; Murtas, F.; Napolitano, M.; Nguyen, F.; Palutan, M.; Pasqualucci, E.; Passeri, A.; Patera, V.; Perfetto, F.; Primavera, M.; Santangelo, P.; Saracino, G.; Sciascia, B.; Sciubba, A.; Sibidanov, A.; Spadaro, T.; Testa, M.; Tortora, L.; Valente, P.; Venanzoni, G.; Versaci, R.; Xu, G.

    2008-01-01

    We have measured the charged kaon lifetime using a sample of 15 × 106 tagged kaon decays. Charged kaons were produced in pairs at the DA?NE phi-factory, e+e- ? phi ? K+K-. The decay of a K+ was tagged by the production of a K- and viceversa. The lifetime was obtained, for both charges, from independent measurements of the decay time and decay length distributions. From fits to the four distributions we find ? = (12.347±0.030) ns.

  4. Measurement of the F-Meson Lifetime

    E-print Network

    Baringer, Philip S.

    1986-04-28

    measured to be (3.5+ii g4+ 0.9) x 10 " s by means of the F @n * decay mode. The measurement was made with the High Resolution Spectrometer at the SLAC e+e storage ring PEP at a center-of-mass energy of 29 GeV. PACS numbers: 13.25. +m, 14.40.Jz... the signai-to-background ra- tio further„decay-angle cuts were applied that favor the decays of the spin-1 @ and the spin-0 F+ in the decay mode F+ —$n + T. he requirements were Icos(&k)'I ) 0.5 in the @ system, and ~cos(8@)'( ( 0.9 in the F+ system...

  5. Picosecond lifetime measurements in147Pm

    NASA Astrophysics Data System (ADS)

    Seo, T.

    1991-12-01

    Half-lives of excited levels in147Pm have been measured using BaF2 scintillators. New values of t1/2 are 2420(10), 43(5), 22(9), 17(10) and 17(10) ps for the 91.1, 410.5, 489.2, 531.0 and 685.9 keV level, respectively. E2 enhancement factors of ?-transitions have been deduced.

  6. Reinforcement Mechanism Of Polyurethane-Urea/Clay Nanocomposites Probed By Positron Annihilation Lifetime Spectroscopy And Dynamic Mechanical Analysis

    SciTech Connect

    Rath, S. K.; Patri, M. [Naval Materials Research Laboratory, Shil-Badlapur Road, Ambernath 421506, Maharastra (India); Sudarshan, K.; Pujari, P. K. [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai-400085 (India); Khakhar, D. V. [Department of Chemical Engineering, Indian Institute of Technology, Powai-76 (India)

    2010-12-01

    A basis for quantitative analysis of the reinforcement mechanism of polyurethane-urea/clay nanocomposites using two characterization methods, positron annihilation life time spectroscopy (PALS) and dynamic mechanical analysis (DMA) is provided. DMA was used to measure the constrained volume fraction of amorphous soft segments induced by nanoclay and the storage modulus of the nanocomposites. The interfacial interactions in the nanocomposites were investigated by PALS. The modulus enhancement of the organoclay nanocomposites was found to have a good correlation with the volume fraction of the constrained region and the interfacial interactions.

  7. Simulations of <1 0 0> edge and 1/2<1 1 1> screw dislocations in ?-iron and tungsten and positron lifetime calculations

    NASA Astrophysics Data System (ADS)

    Staikov, P.; Djourelov, N.

    2013-03-01

    Dislocations in BCC metals are of crucial importance for understanding behavior of fusion materials. In this study model positron lifetime quantum-mechanical calculations have been carried out in the two-component density functional theory (DFT) in local density approximation (LDA) for perfect iron and tungsten lattices, lattices with <1 0 0> edge and 1/2<1 1 1> screw dislocations and several cases in which dislocations interact with a vacancy, bi-vacancy and vacancies containing hydrogen or helium atoms. The core structures of the dislocations have been obtained by MD-simulations using Mendelev and Ackland potentials for iron and Finnis-Sinclair potential for tungsten. The calculated values for iron are 153 ps for edge dislocation and 124 ps for screw dislocation, while for tungsten are 161 and 130 ps, respectively. We report new results for screw dislocation showing that minor dilation of the lattice volume associated with second-order elasticity theory influences the calculated positron lifetime.

  8. A New Method of Neutron Detecton for UCN Lifetime Measurements

    NASA Astrophysics Data System (ADS)

    Morris, C. L.; Salvat, D. J.; Adamek, E.; Bowman, D.; Clayton, S.; Cude, C.; Fox, W.; Hogan, G.; Hickerson, K.; Holley, A. T.; Liu, C.-Y.; Makela, M.; Manus, G.; Penttila, S.; Ramsey, J.; Saunders, A.; Sawtelle, S.; Seestrom, S. J.; Solberg, K.; Vanderwerp, J.; Vorndick, B.; Walstrom, P.; Wang, Z.; Young, A. R.

    2014-03-01

    A number of inconsistent neutron lifetime measurements have been reported. The disagreement among the various measurements made with material neutron traps with ultra-cold neutrons (UCN) suggests unaccounted for systematic errors in these measurements. One potential source of error is due to the long emptying times which may be time dependent due to the UCN phase space evolution in the trap. We present a way to reduce this effect.

  9. Precision Measurement of the ?[0 over b] Baryon Lifetime

    E-print Network

    Williams, Michael

    The ratio of the ?[0 over b] baryon lifetime to that of the B?[superscript 0] meson is measured using 1.0??fb[superscript -1] of integrated luminosity in 7 TeV center-of-mass energy pp collisions at the LHC. The ?[0 over ...

  10. Lifetime measurement of excited states in /sup 105/Ag

    SciTech Connect

    Mittal, V.K.; Govil, I.M.

    1986-11-01

    The levels up to about 2.1 MeV in /sup 105/Ag were excited via /sup 105/Pd(p,n..gamma..) reaction. For the first time, lifetimes of energy levels at 1023, 1042, 1097, 1166, 1243, 1295, 1328, 1386, 1442, 1543, 1558, 1587, 1719, 1923, and 2081 keV have been measured using the Doppler shift attenuation technique.

  11. Measuring Luminescence Lifetime With Help of a DSP

    NASA Technical Reports Server (NTRS)

    Danielson, J. D. S.

    2009-01-01

    An instrument for measuring the lifetime of luminescence (fluorescence or phosphorescence) includes a digital signal processor (DSP) as the primary means of control, generation of excitation signals, and analysis of response signals. The DSP hardware in the present instrument makes it possible to switch among a variety of operating modes by making changes in software only.

  12. Measurement of masses and lifetimes of B hadrons

    E-print Network

    F. Filthaut

    2007-05-04

    We present recent measurements by the CDF and D0 Collaborations at the Tevatron Collider on the masses and lifetimes of B hadrons. The results are compared to predictions based on Heavy Quark Effective Theory, lattice gauge theory, and quark models.

  13. The Development of Plunger Device for Lifetime Measurements in Ciae

    NASA Astrophysics Data System (ADS)

    Wang, J. L.; Wu, X. G.; He, C. Y.; Wu, Y. H.; Li, G. S.; Zheng, Y.; Li, C. B.; Yao, S. H.; Hu, S. P.; Li, H. W.; Liu, J. J.

    2013-11-01

    The lifetime knowledge of a nuclear state provides the essential information on transition probabilities for comparison with theoretical nuclear models. A well-known method for picosecond lifetime measurements of excited nuclear states is Recoil Distance Doppler Shift (RDDS) method. Correspondingly a new plunger based on this technique has been developing in CIAE. We use CAD software and Labview to finish the plunger model design and develop a closed control software. A series of methods such as capacitance method, new skills to flatten the foils etc. are applied in building this plunger. Some tests and the latest results with motion and finite element analysis simulations are discussed in this report.

  14. Low-spin lifetime measurements in {sup 74}Kr

    SciTech Connect

    Valiente-Dobon, J. J. [INFN Laboratori Nazionale di Legnaro, Legnaro (Italy); Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1 (Canada); Svensson, C. E.; Grinyer, G. F.; Hyland, B.; Phillips, A. A.; Schumaker, M. A. [Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1 (Canada); Afanasjev, A. V. [Department of Physics and Astronomy, Mississippi State University, Mississippi 39762 (United States); Ragnarsson, I. [Lund Institute of Technology, P. O. Box 118 S-221 00 Lund (Sweden); Andreoiu, C. [Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1 (Canada); Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 3BX (United Kingdom); Appelbe, D. E. [CLRC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Austin, R. A. E.; Cameron, J. A.; Waddington, J. C. [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4K1 (Canada); Ball, G. C.; Hodgson, D. F.; Smith, M. B. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 (Canada); Carpenter, M. P.; Moore, F.; Mukherjee, G.; Seweryniak, D. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)] (and others)

    2008-02-15

    The nucleus {sup 74}Kr has been populated in the {sup 40}Ca({sup 40}Ca,2p{alpha}){sup 74}Kr fusion-evaporation reaction at a beam energy of 165 MeV and studied using the Gammasphere and Microball multidetector arrays. The lifetimes for low-spin states in the ground-state and two signature-split negative-parity bands were determined using the Doppler-shift attenuation method. These results are discussed together with the lifetimes measured for the high-spin states of these bands and compared with theoretical calculations.

  15. Neutron lifetime measurement with pulsed beam at JPARC: Overview

    NASA Astrophysics Data System (ADS)

    Mishima, Kenji; Ino, Takashi; Taketani, Kaoru; Yamada, Takahito; Katayama, Ryo; Higashi, Nao; Yokoyama, Harumichi; Sumino, Hirochika; Yamashita, Satoru; Sakakibara, Risa; Sugino, Tomoaki; Kitaguchi, Masaaki; Hirota, Katsuya; Shimizu, Hirohiko M.; Tanaka, Genki; Sumi, Naoyuki; Otono, Hidetoshi; Yoshioka, Tamaki; Kitahara, Ryunosuke; Iwashita, Yoshihisa; Oide, Hideyuki; Shima, Tatsushi; Seki, Yoshichika; NOP Collaboration

    2014-09-01

    The neutron lifetime is an important parameter for a test of the Standard Model of elementary particles, as well for the production of light mass nuclei in big bang nucleosynthesis. There are two principally different approaches to measure the neutron lifetime: In-beam methods and storage of ultracold neutron. At present, there is a discrepancy of 8.4 sec (3.8 sigma) between the two methods. We are performing a new In-beam experiment with an intense pulsed neutron source at J-PARC, which has different systematic uncertainties from the previous experiments. We introduce the overview of the experiment and report present status.

  16. Lifetime measurements in neutral and singly ionized vanadium

    SciTech Connect

    Xu Huailiang; Jiang Zhankui; Lundberg, Hans [Department of Physics, Jilin University, Changchun 130023, China, Department of Physics, Lund Institute of Technology, S-221 00 Lund, Sweden, and Department of Physics, Laval University, Quebec, QC, G1K 7P4 (Canada); Department of Physics, Jilin University, Changchun 130023, China, and Department of Physics, Yantai University, Yantai, 264005 (China); Department of Physics, Lund Institute of Technology, S-221 00 Lund (Sweden)

    2006-12-15

    Radiative lifetimes of ten odd-parity levels of V I belonging to the 3d{sup 3}4s4p and 3d{sup 4}4p configurations and of 11 odd-parity levels of V II belonging to the 3d{sup 3}4p configuration are reported. The lifetimes were measured with use of single-step excitation and time-resolved fluorescence spectroscopy. The neutral and singly ionized vanadium atoms were produced in a laser-induced vanadium plasma.

  17. Inhomogeneous dephasing masks coherence lifetimes in ensemble measurements

    SciTech Connect

    Pelzer, Kenley M.; Griffin, Graham B.; Engel, Gregory S. [James Franck Institute and Department of Chemistry, University of Chicago, Chicago, Illinois 60637 (United States); Gray, Stephen K. [Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2012-04-28

    An open question at the forefront of modern physical sciences is what role, if any, quantum effects may play in biological sensing and energy transport mechanisms. One area of such research concerns the possibility of coherent energy transport in photosynthetic systems. Spectroscopic evidence of long-lived quantum coherence in photosynthetic light-harvesting pigment protein complexes (PPCs), along with theoretical modeling of PPCs, has indicated that coherent energy transport might boost efficiency of energy transport in photosynthesis. Accurate assessment of coherence lifetimes is crucial for modeling the extent to which quantum effects participate in this energy transfer, because such quantum effects can only contribute to mechanisms proceeding on timescales over which the coherences persist. While spectroscopy is a useful way to measure coherence lifetimes, inhomogeneity in the transition energies across the measured ensemble may lead to underestimation of coherence lifetimes from spectroscopic experiments. Theoretical models of antenna complexes generally model a single system, and direct comparison of single system models to ensemble averaged experimental data may lead to systematic underestimation of coherence lifetimes, distorting much of the current discussion. In this study, we use simulations of the Fenna-Matthews-Olson complex to model single complexes as well as averaged ensembles to demonstrate and roughly quantify the effect of averaging over an inhomogeneous ensemble on measured coherence lifetimes. We choose to model the Fenna-Matthews-Olson complex because that system has been a focus for much of the recent discussion of quantum effects in biology, and use an early version of the well known environment-assisted quantum transport model to facilitate straightforward comparison between the current model and past work. Although ensemble inhomogeneity is known to lead to shorter lifetimes of observed oscillations (simply inhomogeneous spectral broadening in the time domain), this important fact has been left out of recent discussions of spectroscopic measurements of energy transport in photosynthesis. In general, these discussions have compared single-system theoretical models to whole-ensemble laboratory measurements without addressing the effect of inhomogeneous dephasing. Our work addresses this distinction between single system and ensemble averaged observations, and shows that the ensemble averaging inherent in many experiments leads to an underestimation of coherence lifetimes in individual systems.

  18. Doppler broadening positron annihilation measurements of lattice defects during transformation cycling in Cu-Zn-Al alloy

    SciTech Connect

    Zhongguo Wei (China Univ. of Mining and Tech., Jiangsu (China). Dept. of Mechanical Engineering); Dazhi Yang (Dalian Univ. of Technology (China). Dept. of Materials Engineering); Wu, K.H. (Florida International Univ., Miami, FL (United States). Dept. of Mechanical Engineering)

    1993-09-01

    Positron Annihilation Techniques have been proved to be a characteristic tool in the research of lattice defects in metals and alloys. Especially, vacancy type point defects and dislocations can be detected. During recent years, researchers have completed Doppler broadening and positron lifetime measurements to study the phase transformations and behavior of vacancies in CuZnAl, CuAlNi, CuAlMn and NiTi shape memory alloys. Also, research has demonstrated that positrons are sensitive to the evolution of defects, during aging and thermal cycling. From common knowledge, the authors know that copper base shape memory alloys contain a high concentration of excess vacancies once the alloys are quenched from the high temperature single beta phase. Also, the excess vacancies play a very important role in the complicated aging effects of both the parent and martensite phases. The present work intends, by means of Doppler broadening positron annihilation measurements, to investigate the behavior of quenched-in vacancies and the evolution of defects during martensitic transformation cycling.

  19. The temperature dependence of free volume in phenyl salicylate and its relation to structural dynamics: A positron annihilation lifetime and pressure-volume-temperature study

    NASA Astrophysics Data System (ADS)

    Dlubek, G.; Shaikh, M. Q.; Raetzke, K.; Faupel, F.; Pionteck, J.; Paluch, M.

    2009-04-01

    Positron annihilation lifetime spectroscopy (PALS) and pressure-volume-temperature (PVT) experiments were performed to characterize the temperature dependent microstructure of the hole free volume in the low molecular weight glass-former phenyl salicylate (salol). The PALS spectra were analyzed with the new routine LT9.0 and the volume distribution of subnanometer size holes characterized by its mean ?vh? and standard deviation ?h was calculated. Crystallization of the amorphous sample was observed in the temperature range above 250 K, which leads to a vanishing of the positronium formation. The positronium signal recovered after melting at 303 K. A combination of PALS with PVT data enabled us to calculate the specific density Nh', the specific volume Vf, and the fraction of holes fh in the amorphous state. From comparison with dielectric measurements in the temperature range above TB=265 K, it was found that the primary structural relaxation slows down with temperature, faster than the shrinkage of the hole free volume Vf would predict, on the basis of the Cohen-Turnbull (CT) free volume theory. CT plots can be linearized by replacing Vf of the CT theory by (Vf-?V), where ?V is a volume correction term. This was interpreted as indication that the lower wing of the hole size distribution contains holes too small to show a liquidlike behavior in their surroundings. Peculiarities of the relaxation behavior below TB=265 K and the possible validity of the Cohen-Grest free volume model are discussed.

  20. Behaviour of Pluronic P84 block copolymer micelles above the gelification temperature as probed by positron annihilation lifetime spectroscopy.

    PubMed

    Messaoud, Taoufik; Duplâtre, Gilles; Waton, Gilles; Michels, Bernard

    2005-11-21

    The new method based on positron annihilation lifetime spectroscopy (PALS) to determine both the mean core radius, R(core), and aggregation number, N(ag), of micelles is applied to the study of aqueous solutions of the triblock Pluronic P84 copolymer as a function of temperature (T), beyond the gelification point (334 K). Two long-lived components appear in the PALS spectra, ascribed to triplet positronium in the water bulk (o-Ps(aq)) and in the organic core of the micelles (o-Ps(org)). Of the various fitting parameters, only the lifetime of the latter species, tau4, and the micellar parameters, R(core) and N(ag), disclose the occurrence of gelification by first increasing up to 334 K, then decreasing. By contrast to what is known in case of phase transition, none of the parameters shows any abrupt change at 334 K, whereas the macroscopic viscosity of the solutions suffers a drastic increase. This is attributed to the fact that positronium is sensitive to the microviscosity of the solutions. At the transition point, the properties of the polyoxipropylene aggregates forming the organic core of the P84 micelles are not greatly affected. Furthermore, the fact that the experimental N(ag) values coincide with those calculated for spheres, from the R(core) values, indicates that the shape of the P84 cores does not change significantly after gelification. The onset of gelification results from a decrease in the hydrogen bonding interactions in the solution with an ensuing relative increase in the interactions between the polyoxipropylene (PPO) groups, initially forming the corona of the P84 micelles, in an intermicellar mode. This increased solicitation of the PPO groups outside their initial location would result in depletion in the number of surfactant molecules forming the micelles, viz. a decrease in both R(core) and N(ag) above 334 K. From the data, additional information can be gained regarding the local viscosity and surface tension in the micellar cores. PMID:16358034

  1. Measurement of the average lifetime of hadrons containing bottom quarks

    SciTech Connect

    Klem, D.E.

    1986-06-01

    This thesis reports a measurement of the average lifetime of hadrons containing bottom quarks. It is based on data taken with the DELCO detector at the PEP e/sup +/e/sup -/ storage ring at a center of mass energy of 29 GeV. The decays of hadrons containing bottom quarks are tagged in hadronic events by the presence of electrons with a large component of momentum transverse to the event axis. Such electrons are identified in the DELCO detector by an atmospheric pressure Cherenkov counter assisted by a lead/scintillator electromagnetic shower counter. The lifetime measured is 1.17 psec, consistent with previous measurements. This measurement, in conjunction with a limit on the non-charm branching ratio in b-decay obtained by other experiments, can be used to constrain the magnitude of the V/sub cb/ element of the Kobayashi-Maskawa matrix to the range 0.042 (+0.005 or -0.004 (stat.), +0.004 or -0.002 (sys.)), where the errors reflect the uncertainty on tau/sub b/ only and not the uncertainties in the calculations which relate the b-lifetime and the element of the Kobayashi-Maskawa matrix.

  2. A precision measurement of the average lifetime of B hadrons

    NASA Astrophysics Data System (ADS)

    Abreu, P.; Adam, W.; Adye, T.; Agasi, E.; Aleksan, R.; Alekseev, G. D.; Allport, P.; Almehed, S.; Almeida Junior, F. M. L.; Alvsvaag, S. J.; Amaldi, U.; Andreazza, A.; Antilogus, P.; Apel, W.-D.; Apsimon, R. J.; Arnoud, Y.; Åsman, B.; Augustin, J.-E.; Augustinus, A.; Baillon, P.; Bambade, P.; Barao, F.; Barate, R.; Barbiellini, G.; Bardin, D. Y.; Barker, G. J.; Baroncelli, A.; Barring, O.; Barrio, J. A.; Bartl, W.; Bates, M. J.; Battaglia, M.; Baubillier, M.; Becks, K.-H.; Begalli, M.; Beilliere, P.; Belokopytov, Yu.; Beltran, P.; Benvenuti, A. C.; Berggren, M.; Bertrand, D.; Bianchi, F.; Bigi, M.; Bilenky, M. S.; Billoir, P.; Bjarne, J.; Bloch, D.; Blocki, J.; Blyth, S.; Bocci, V.; Bogolubov, P. N.; Bolognese, T.; Bonesini, M.; Bonivento, W.; Booth, P. S. L.; Borisov, G.; Bosio, C.; Bostjancic, B.; Bosworth, S.; Botner, O.; Bouquet, B.; Bourdarios, C.; Bowcock, T. J. V.; Bozzo, M.; Braibant, S.; Branchini, P.; Brand, K. D.; Brenner, R. A.; Briand, H.; Bricman, C.; Brillault, L.; Brown, R. C. A.; Brunet, J.-M.; Bugge, L.; Buran, T.; Buys, A.; Buytaert, J. A. M. A.; Caccia, M.; Calvi, M.; Rozas, A. J. Camacho; Campion, R.; Camporesi, T.; Canale, V.; Cabkocak, K.; Cao, F.; Carena, F.; Carrilho, P.; Carroll, L.; Cases, R.; Caso, C.; Castillo Gimenez, M. V.; Cattai, A.; Cavallo, F. R.; Cerrito, L.; Chabaud, V.; Chan, A.; Charpentier, Ph.; Chauveau, J.; Checchia, P.; Chelkov, G. A.; Chevalier, L.; Chliapnikov, P.; Chorowicz, V.; Chrin, J. T. M.; Cindro, V.; Collins, P.; Contreras, J. L.; Contri, R.; Cortina, E.; Cosme, G.; Couchot, F.; Crawley, H. B.; Crennell, D.; Crosetti, G.; Crosetti, G.; Maestro, J. Cuevas; Czellar, S.; Dahl-Jensen, E.; Dahm, J.; Dalmagne, B.; Dam, M.; Damgaard, G.; Daubie, E.; Daum, A.; Dauncey, P. D.; Davenport, M.; Davies, J.; da Silva, W.; Defoix, C.; Delpierre, P.; Demaria, N.; de Angelis, A.; de Boeck, H.; de Boer, W.; de Brabandere, S.; de Clercq, C.; de Fez Laso, M. D. M.; de La Vaissiere, C.; de Lotto, D.; de Min, A.; de Paula, L.; Dijkstra, H.; di Ciaccio, L.; Djama, F.; Dolbeau, J.; Donszelmann, M.; Doroba, K.; Dracos, M.; Drees, J.; Dris, M.; Dufour, Y.; Dupont, F.; Edsall, D.; Eek, L.-O.; Ehret, R.; Ekelof, T.; Ekspong, G.; Peisert, A. Elliot; Elsing, M.; Engel, J.-P.; Ershaidat, N.; Santo, M. Espirito; Falaleev, V.; Fassouliotis, D.; Feindt, M.; Fenyuk, A.; Ferrer, A.; Filipas, T. A.; Firestone, A.; Foeth, H.; Fokitis, E.; Fontanelli, F.; Forbes, K. A. J.; Formenti, F.; Fousset, J.-L.; Francon, S.; Franek, B.; Frenkiel, P.; Fries, D. C.; Frodesen, A. G.; Fruhwirth, R.; Fulda-Quenzer, F.; Fustenau, H.; Fuster, J.; Gamba, D.; Gandelman, M.; Garcia, C.; Garcia, J.; Gaspar, C.; Gasparini, U.; Gavillet, Ph.; Gazis, E. N.; Gerber, J.-P.; Giacomelli, P.; Gillespie, D.; Gokieli, R.; Golob, B.; Golovatyuk, V. M.; Cadenas, J. J. Gomez Y.; Gopal, G.; Gorn, L.; Gorski, M.; Gracco, V.; Grard, F.; Graziani, E.; Grosdidier, G.; Grossetete, B.; Gunnarsson, P.; Guy, J.; Haedinger, U.; Hahn, F.; Hahn, M.; Hahn, S.; Haider, S.; Hajduk, Z.; Hakansson, A.; Hallgren, A.; Hamacher, K.; Hamel de Monchenault, G.; Hao, W.; Harris, F. J.; Hedberg, V.; Henriques, R.; Hernandez, J. J.; Hernando, J. A.; Herquet, P.; Herr, H.; Hessing, T. L.; Higgins, C. O.; Higon, E.; Hilke, H. J.; Hill, T. S.; Hodgson, S. D.; Holmogren, S.-O.; Holt, P. J.; Holthuizen, D.; Honore, P. F.; Houlden, M.; Hrubec, J.; Huet, K.; Hultqvist, K.; Ioannou, P.; Iversen, P.-S.; Jackson, J. N.; Jacobsson, R.; Jalocha, P.; Jarlskog, G.; Jarry, P.; Jean-Marie, B.; Johansson, E. K.; Jonker, M.; Jonsson, L.; Juillot, P.; Kaiser, M.; Kalmus, G.; Kapusta, F.; Karlsson, M.; Karvelas, E.; Katsanevas, S.; Katsoufis, E. C.; Keranen, R.; Khomenko, B. A.; Khovanski, N. N.; King, B.; Kjaer, N. J.; Klein, H.; Klovning, A.; Kluit, P.; Koch-Mehrin, A.; Koehne, J. H.; Koene, B.; Kokkionias, P.; Koratzinos, M.; Korcyl, K.; Korytov, A. V.; Kostioukhine, V.; Kourkoumelis, C.; Kouznetsov, O.; Kramer, P. H.; Krammer, M.; Kreuter, C.; Krolikowski, J.; Kronkvist, I.; Krupinski, W.; Kulka, K.; Kurvinen, K.; Lacasta, C.; Lambropoulos, C.; Lamsa, J. W.; Lanceri, L.; Langefeld, P.; Lapin, V.; Last, I.; Laugier, J.-P.; Lauhakangas, R.; Leder, G.; Ledroit, F.; Leitner, R.; Lemoigne, Y.; Lemonne, J.; Lenzen, G.; Lepeltier, V.; Lesiak, T.; Levy, J. M.; Lieb, E.; Liko, D.; Linder, R.; Lipnicka, A.; Lippi, I.; Loerstad, B.; Lokajicek, M.; Loken, J. G.; Lopez-Feernandez, A.; Lopez Aguera, M. A.; Los, M.; Loukas, D.; Lozano, J. J.; Lutz, P.; Lyons, L.; Maehlum, G.; Maillard, J.; Maio, A.; Maltezos, A.; Mandl, F.; Marco, J.; Marechal, B.; Margoni, M.; Marin, J.-C.; Mariotti, C.; Markou, A.; Maron, T.; Marti, S.; Martinez-Rivero, C.; Martinez-Vidal, F.; Matorras, F.; Mattekuzzi, C.; Mathiae, G.; Mazzucato, M.; Cubbin, M. Mc.; Kay, R. Mc; Nulty, R. Mc.

    1994-03-01

    The average lifetime of B hadrons was measured using data collected with the DELPHI detector at the LEP collider during 1991 and 1992. The measurement was performed using two different anayses. The first method was an improvement on a previous technique, which used charged particle impact parameter distributions. This analysis measured an average lifetime for B hadrons of (1) 10052_2005_Article_BF01577539_TeX2GIFE1.gif tau _B = 1.542 ± 0.021(stat.) ± 0.045(syst.)ps. The second method was based on a new technique, which used inclusively reconstructed secondary vertices to measure (2) 10052_2005_Article_BF01577539_TeX2GIFE2.gif tau _B = 1.599 ± 0.014(stat.) ± 0.035(syst.)ps. Taking into account both the statistical and systematic corelations, the results of these two methods were combined to give an average lifetime for B hadrons of (3) 10052_2005_Article_BF01577539_TeX2GIFE3.gif tau _B = 1.582 ± 0.012(stat.) ± 0.032(syst.)ps.

  3. Measurement of the B sup 0 -meson lifetime

    SciTech Connect

    Wagner, S.R.; Hinshaw, D.A.; Ong, R.A.; Snyder, A.; Abrams, G.; Adolphsen, C.E.; Akerlof, C.; Alexander, J.P.; Alvarez, M.; Amidei, D.; Baden, A.R.; Ballam, J.; Barish, B.C.; Barklow, T.; Barnett, B.A.; Bartelt, J.; Blockus, D.; Bonvicini, G.; Boyarski, A.; Boyer, J.; Brabson, B.; Breakstone, A.; Brom, J.M.; Bulos, F.; Burchat, P.R.; Burke, D.L.; Butler, F.; Calvino, F.; Cence, R.J.; Chapman, J.; Cords, D.; Coupal, D.P.; DeStaebler, H.C.; Dorfan, D.E.; Dorfan, J.M.; Drell, P.S.; Feldman, G.J.; Fernandez, E.; Field, R.C.; Ford, W.T.; Fordham, C.; Frey, R.; Fujino, D.; Gan, K.K.; Gidal, G.; Gladney, L.; Glanzman, T.; Gold, M.S.; Goldhaber, G.; Green, A.; Grosse-Wiesmann, P.; Haggerty, J.; Hanson, G.; Harr, R.; Harris, F.A.; Hawkes, C.M.; Hayes, K.; Herrup, D.; Heusch, C.A.; Himel, T.; Hollebeek, R.J.; Hutchinson, D.; Hylen, J.; Innes, W.R.; Jaffre, M.; Jaros, J.A.; Juricic, I.; Kadyk, J.A.; Karlen, D.; Kent, J.; Klein, S.R.; Koska, W.; Kozanecki, W.; Lankford, A.J.; Larsen, R.R.; LeClair

    1990-03-05

    We report a measurement of the lifetime of the {ital B}{sup 0} meson based upon 29-GeV {ital e}{sup +}{ital e}{sup {minus}} annihilation data taken with the Mark II detector at the SLAC storage ring PEP. The {ital B}{sup 0} mesons are tagged by their decays into {ital D}{sup *{minus}}{ital e}{sup +}{nu} and {ital D}{sup *{minus}}{mu}{sup +}{nu}, where the {ital D}{sup *{minus}} is tagged by its decay into {pi}{sup {minus}}{ital {bar D}}{sup 0}. We reconstruct the decay vertices of 15 {ital B}{sup 0}-meson candidates and measure the {ital B}{sup 0} lifetime to be 1.20{sup +0.52}{sub {minus}0.36}{sup +0.16}{sub 0.14} psec.

  4. Lifetime measurements and shape coexistence in {sup 144}Dy

    SciTech Connect

    Procter, M. G.; Cullen, D. M.; Niclasen, B.; Mason, P. J. R.; Rigby, S. V.; Dare, J. A.; Lumley, N. M. [Schuster Laboratory, University of Manchester, Manchester M13 9PL (United Kingdom); Scholey, C.; Greenlees, P. T.; Jakobsson, U.; Jones, P. M.; Julin, R.; Juutinen, S.; Ketelhut, S.; Leino, M.; Nyman, M.; Puurunen, A.; Rahkila, P.; Ruotsalainen, P.; Saren, J. [Department of Physics, University of Jyvaeskylae, FIN-40014 Jyvaeskylae (Finland)

    2010-05-15

    The known level scheme of {sup 144}Dy has been extended and lifetime measurements have been made with the recoil-distance Doppler-shift method. Reduced transition probabilities and deformations have been determined for four low-lying transitions. These states form part of the first observed band crossing, giving information on the change in nuclear deformation resulting from the rearrangement of h{sub 11/2} protons in the nucleus. Two bands built upon excited 10{sup +} states have been assigned pi(h{sub 11/2}){sup 2} prolate and nu(h{sub 11/2}){sup -2} oblate configurations with tau=12(2)ps and 0.01lifetimes are reasoned to be a result of shape coexistence at low energy and moderate spin. A known four-quasiparticle dipole band has been extended to higher spin and lifetime measurements suggest a long-lived bandhead state. In this case, the excited states in the band may be consistent with a shears model interpretation of a magnetic dipole rotor. However, the measured B(M1)/B(E2) branching ratios reveal a larger than expected deformed rotational component compared with that in the analogous band in the lower mass isotone {sup 142}Gd.

  5. Measurements of the Bs0 and ?b0 lifetimes

    NASA Astrophysics Data System (ADS)

    OPAL Collaboration; Ackerstaff, K.; Alexander, G.; Allison, J.; Altekamp, N.; Anderson, K. J.; Anderson, S.; Arcelli, S.; Asai, S.; Ashby, S. F.; Axen, D.; Azuelos, G.; Ball, A. H.; Barberio, E.; Barlow, R. J.; Bartoldus, R.; Batley, J. R.; Baumann, S.; Bechtluft, J.; Beeston, C.; Behnke, T.; Bell, A. N.; Bell, K. W.; Bella, G.; Bentvelsen, S.; Bethke, S.; Betts, S.; Biebel, O.; Biguzzi, A.; Bird, S. D.; Blobel, V.; Bloodworth, I. J.; Bloomer, J. E.; Bobinski, M.; Bock, P.; Bonacorsi, D.; Boutemeur, M.; Braibant, S.; Brigliadori, L.; Brown, R. M.; Burckhart, H. J.; Burgard, C.; Bürgin, R.; Capiluppi, P.; Carnegie, R. K.; Carter, A. A.; Carter, J. R.; Chang, C. Y.; Charlton, D. G.; Chrisman, D.; Clarke, P. E. L.; Cohen, I.; Conboy, J. E.; Cooke, O. C.; Couyoumtzelis, C.; Coxe, R. L.; Cuffiani, M.; Dado, S.; Dallapiccola, C.; Dallavalle, G. M.; Davis, R.; de Jong, S.; del Pozo, L. A.; Desch, K.; Dienes, B.; Dixit, M. S.; Doucet, M.; Duchovni, E.; Duckeck, G.; Duerdoth, I. P.; Eatough, D.; Edwards, J. E. G.; Estabrooks, P. G.; Evans, H. G.; Evans, M.; Fabbri, F.; Fanfani, A.; Fanti, M.; Faust, A. A.; Feld, L.; Fiedler, F.; Fierro, M.; Fischer, H. M.; Fleck, I.; Folman, R.; Fong, D. G.; Foucher, M.; Fürtjes, A.; Futyan, D. I.; Gagnon, P.; Gary, J. W.; Gascon, J.; Gascon-Shotkin, S. M.; Geddes, N. I.; Geich-Gimbel, C.; Geralis, T.; Giacomelli, G.; Giacomelli, P.; Giacomelli, R.; Gibson, V.; Gibson, W. R.; Gingrich, D. M.; Glenzinski, D.; Goldberg, J.; Goodrick, M. J.; Gorn, W.; Grandi, C.; Gross, E.; Grunhaus, J.; Gruwé, M.; Hajdu, C.; Hanson, G. G.; Hansroul, M.; Hapke, M.; Hargrove, C. K.; Hart, P. A.; Hartmann, C.; Hauschild, M.; Hawkes, C. M.; Hawkings, R.; Hemingway, R. J.; Herndon, M.; Herten, G.; Heuer, R. D.; Hildreth, M. D.; Hill, J. C.; Hillier, S. J.; Hobson, P. R.; Hocker, A.; Homer, R. J.; Honma, A. K.; Horváth, D.; Hossain, K. R.; Howard, R.; Hüntemeyer, P.; Hutchcroft, D. E.; Igo-Kemenes, P.; Imrie, D. C.; Ingram, M. R.; Ishii, K.; Jawahery, A.; Jeffreys, P. W.; Jeremie, H.; Jimack, M.; Joly, A.; Jones, C. R.; Jones, G.; Jones, M.; Jost, U.; Jovanovic, P.; Junk, T. R.; Kanzaki, J.; Karlen, D.; Kartvelishvili, V.; Kawagoe, K.; Kawamoto, T.; Kayal, P. I.; Keeler, R. K.; Kellogg, R. G.; Kennedy, B. W.; Kirk, J.; Klier, A.; Kluth, S.; Kobayashi, T.; Kobel, M.; Koetke, D. S.; Kokott, T. P.; Kolrep, M.; Komamiya, S.; Kress, T.; Krieger, P.; von Krogh, J.; Kyberd, P.; Lafferty, G. D.; Lahmann, R.; Lai, W. P.; Lanske, D.; Lauber, J.; Lautenschlager, S. R.; Layter, J. G.; Lazic, D.; Lee, A. M.; Lefebvre, E.; Lellouch, D.; Letts, J.; Levinson, L.; Lloyd, S. L.; Loebinger, F. K.; Long, G. D.; Losty, M. J.; Ludwig, J.; Lui, D.; Macchiolo, A.; MacPherson, A.; Mannelli, M.; Marcellini, S.; Markopoulos, C.; Markus, C.; Martin, A. J.; Martin, J. P.; Martinez, G.; Mashimo, T.; Mättig, P.; McDonald, W. J.; McKenna, J.; McKigney, E. A.; McMahon, T. J.; McPherson, R. A.; Meijers, F.; Menke, S.; Merritt, F. S.; Mes, H.; Meyer, J.; Michelini, A.; Mikenberg, G.; Miller, D. J.; Mincer, A.; Mir, R.; Mohr, W.; Montanari, A.; Mori, T.; Müller, U.; Mihara, S.; Nagai, K.; Nakamura, I.; Neal, H. A.; Nellen, B.; Nisius, R.; O'Neale, S. W.; Oakham, F. G.; Odorici, F.; Ogren, H. O.; Oh, A.; Oldershaw, N. J.; Oreglia, M. J.; Orito, S.; Pálinkás, J.; Pásztor, G.; Pater, J. R.; Patrick, G. N.; Patt, J.; Perez-Ochoa, R.; Petzold, S.; Pfeifenschneider, P.; Pilcher, J. E.; Pinfold, J.; Plane, D. E.; Poffenberger, P.; Poli, B.; Posthaus, A.; Rembser, C.; Robertson, S.; Robins, S. A.; Rodning, N.; Roney, J. M.; Rooke, A.; Rossi, A. M.; Routenburg, P.; Rozen, Y.; Runge, K.; Runolfsson, O.; Ruppel, U.; Rust, D. R.; Rylko, R.; Sachs, K.; Saeki, T.; Sang, W. M.; Sarkisyan, E. K. G.; Sbarra, C.; Schaile, A. D.; Schaile, O.; Scharf, F.; Scharff-Hansen, P.; Schieck, J.; Schleper, P.; Schmitt, B.; Schmitt, S.; Schöning, A.; Schröder, M.; Schultz-Coulon, H. C.; Schumacher, M.; Schwick, C.; Scott, W. G.; Shears, T. G.; Shen, B. C.; Shepherd-Themistocleous, C. H.; Sherwood, P.; Siroli, G. P.; Sittler, A.; Skillman, A.; Skuja, A.; Smith, A. M.; Snow, G. A.; Sobie, R.; Söldner-Rembold, S.; Springer, R. W.; Sproston, M.; Stephens, K.; Steuerer, J.; Stockhausen, B.; Stoll, K.; Strom, D.; Ströhmer, R.; Szymanski, P.; Tafirout, R.; Talbot, S. D.; Tanaka, S.; Taras, P.; Tarem, S.; Teuscher, R.; Thiergen, M.; Thomson, M. A.; von Törne, E.; Torrence, E.; Towers, S.; Trigger, I.; Trócsányi, Z.; Tsur, E.; Turcot, A. S.; Turner-Watson, M. F.; Utzat, P.; van Kooten, R.; Verzocchi, M.; Vikas, P.; Vokurka, E. H.; Voss, H.; Wäckerle, F.; Wagner, A.; Ward, C. P.; Ward, D. R.; Watkins, P. M.; Watson, A. T.; Watson, N. K.; Wells, P. S.; Wermes, N.; White, J. S.; Wilkens, B.; Wilson, G. W.; Wilson, J. A.; Wyatt, T. R.

    1998-04-01

    This paper presents updated measurements of the lifetimes of the Bs0 meson and the ?b0 baryon using 4.4 million hadronic Z0 decays recorded by the OPAL detector at LEP from 1990 to 1995. A sample of Bs0 decays is obtained using Ds-l+ combinations, where the Ds- is fully reconstructed in the ??-, K*0K- and K-K0S decay channels and partially reconstructed in the ?l-?¯X decay mode. A sample of ?b0 decays is obtained using ?c+l- combinations, where the ?c+ is fully reconstructed in its decay to a pK-?+ final state and partially reconstructed in the ?l+?X decay channel. From 172+/-28 Ds-l+ combinations attributed to Bs0 decays, the measured lifetime is ?(Bs0)=1.50+0.16-0.15+/- 0.04 ps, where the errors are statistical and systematic, respectively. From the 129+/-25 ?c+l- combinations attributed to ?b0 decays, the measured lifetime is ?(?b0)=1.29+0.24- 0.22+/-0.06 ps, where the errors are statistical and systematic, respectively.

  6. Positron interactions with water–total elastic, total inelastic, and elastic differential cross section measurements

    SciTech Connect

    Tattersall, Wade [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia) [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Centre for Antimatter-Matter Studies, School of Engineering and Physical Sciences, James Cook University, Townsville, 4810 Queensland (Australia); Chiari, Luca [Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide 5001, South Australia (Australia)] [Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide 5001, South Australia (Australia); Machacek, J. R.; Anderson, Emma; Sullivan, James P. [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia)] [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); White, Ron D. [Centre for Antimatter-Matter Studies, School of Engineering and Physical Sciences, James Cook University, Townsville, 4810 Queensland (Australia)] [Centre for Antimatter-Matter Studies, School of Engineering and Physical Sciences, James Cook University, Townsville, 4810 Queensland (Australia); Brunger, M. J. [Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide 5001, South Australia (Australia) [Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide 5001, South Australia (Australia); Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur (Malaysia); Buckman, Stephen J. [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia) [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur (Malaysia); Garcia, Gustavo [Instituto de F?sica Fundamental, Consejo Superior de Investigationes Cient?ficas (CSIC), Serrano 113-bis, E-28006 Madrid (Spain)] [Instituto de F?sica Fundamental, Consejo Superior de Investigationes Cient?ficas (CSIC), Serrano 113-bis, E-28006 Madrid (Spain); Blanco, Francisco [Departamento de F?sica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, E-28040 Madrid (Spain)] [Departamento de F?sica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, E-28040 Madrid (Spain)

    2014-01-28

    Utilising a high-resolution, trap-based positron beam, we have measured both elastic and inelastic scattering of positrons from water vapour. The measurements comprise differential elastic, total elastic, and total inelastic (not including positronium formation) absolute cross sections. The energy range investigated is from 1 eV to 60 eV. Comparison with theory is made with both R-Matrix and distorted wave calculations, and with our own application of the Independent Atom Model for positron interactions.

  7. Spectral and lifetime domain measurements of rat brain tumors

    PubMed Central

    Haidar, D. Abi; Leh, B.; Zanello, M.; Siebert, R.

    2015-01-01

    During glioblastoma surgery, delineation of the brain tumor margins is difficult because the infiltrated and normal tissues have the same visual appearance. We use a fiber-optical fluorescence probe for spectroscopic and time domain measurements to assist surgeon in differentiating the healthy and the infiltrated tissues. First study was performed on rats that were previously injected with tumorous cells. Measurements of endogenous tissue fluorescence were performed on fresh and fixed rat tumor brain slices. Spectral characteristics, fluorescence redox ratios and fluorescence lifetime measurements were analyzed. The study aimed at defining an optical index that can act as an indicator for discriminating healthy from tumorous tissue. PMID:25909006

  8. Lifetime Measurements and Coulomb Excitation of Light Hg Nuclei

    NASA Astrophysics Data System (ADS)

    Petts, A.; Butler, P. A.; Grahn, T.; Blazhev, A.; Bree, N.; Bruyneel, B.; Cederkäll, J.; Clement, E.; Cocolios, T. E.; Dewald, A.; Eberth, J.; Fraile, L.; Fransen, C.; Hornillos, M. B. Gómez; Greenlees, P. T.; Görgen, A.; Guttormsen, M.; Hadynska, K.; Helariutta, K.; Herzberg, R.-D.; Huyse, M.; Jenkins, D. G.; Jolie, J.; Jones, P.; Julin, R.; Juutinen, S.; Ketelhut, S.; Knapen, S.; Kröll, T.; Krü; cken, R.; Larsen, A. C.; Leino, M.; Ljungvall, J.; Maierbeck, P.; Marley, P. L.; Melon, B.; Napiorkowski, P. J.; Nyman, M.; Page, R. D.; Pakarinen, J.; Pascovici, G.; Patronis, N.; Peura, P. J.; Piselli, E.; Pissulla, Th.; Rahkila, P.; Reiter, P.; Sarén, J.; Scheck, M.; Scholey, C.; Semchenkov, A.; Siem, S.; Stefanescu, I.; Sorri, J.; Uusitalo, J.; Van de Walle, J.; Van Duppen, P.; Voulot, D.; Wadsworth, R.; Warr, N.; Weisshaar, D.; Wenander, F.; Zielinska, M.

    2009-01-01

    Two complementary experimental programs have taken place to investigate the origin and evolution of shape coexistence in the light mercury region. Recoil Distance Doppler-shift measurements were performed at the University of Jyväskylä utilizing the Köln plunger device in conjunction with the JUROGAM+RITU+GREAT setup. In addition, Coulomb excitation measurements of 184,186,188Hg were performed at REX-ISOLDE using the MINIBALL Ge-detector array. The results of the lifetime measurements of the yrast states up to I? = 10+ in 182Hg are reported. Preliminary analysis of the Coulomb excitation data is also discussed.

  9. Free volume in imidazolium triflimide ([C{sub 3}MIM][NTf{sub 2}]) ionic liquid from positron lifetime: Amorphous, crystalline, and liquid states

    SciTech Connect

    Dlubek, G. [Institut fuer Physik, Martin-Luther-Universitaet Halle-Wittenberg, Von-Danckelmann-Platz 3, 06120 Halle (Germany); ITA Institut fuer Innovative Technologien, Koethen/Halle, Wiesenring 4, D-06120 Lieskau (Germany); Yu, Yang; Krause-Rehberg, R. [Institut fuer Physik, Martin-Luther-Universitaet Halle-Wittenberg, Von-Danckelmann-Platz 3, 06120 Halle (Germany); Beichel, W.; Bulut, S.; Pogodina, N.; Krossing, I.; Friedrich, Ch. [Freiburger Materialforschungszentrum (FMF), Albert-Ludwigs-Universitaet Freiburg, Stefan-Meier-Strasse 21, Germany and Institut fuer Anorganische Chemie, Albert-Ludwigs-Universitaet Freiburg, Albertstrasse 21, D-79104 Freiburg i. Br. (Germany)

    2010-09-28

    Positron annihilation lifetime spectroscopy (PALS) is used to study the ionic liquid 1-methyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide [C{sub 3}MIM][NTf{sub 2}] in the temperature range between 150 and 320 K. The positron decay spectra are analyzed using the routine LifeTime-9.0 and the size distribution of local free volumes (subnanometer-size holes) is calculated. This distribution is in good agreement with Fuerth's classical hole theory of liquids when taking into account Fuerth's hole coalescence hypothesis. During cooling, the liquid sample remains in a supercooled, amorphous state and shows the glass transition in the ortho-positronium (o-Ps) lifetime at 187 K. The mean hole volume varies between 70 A{sup 3} at 150 K and 250 A{sup 3} at 265-300 K. From a comparison with the macroscopic volume, the hole density is estimated to be constant at 0.20x10{sup 21} g{sup -1} corresponding to 0.30 nm{sup -3} at 265 K. The hole free volume fraction varies from 0.023 at 185 K to 0.073 at T{sub m}+12 K=265 K and can be estimated to be 0.17 at 430 K. It is shown that the viscosity follows perfectly the Cohen-Turnbull free volume theory when using the free volume determined here. The heating run clearly shows crystallization at 200 K by an abrupt decrease in the mean <{tau}{sub 3}> and standard deviation {sigma}{sub 3} of the o-Ps lifetime distribution and an increase in the o-Ps intensity I{sub 3}. The parameters of the second lifetime component <{tau}{sub 2}> and {sigma}{sub 2} behave parallel to the o-Ps parameters, which also shows the positron's (e{sup +}) response to structural changes. During melting at 253 K, all lifetime parameters recover to the initial values of the liquid. An abrupt decrease in I{sub 3} is attributed to the solvation of e{sup -} and e{sup +} particles. Different possible interpretations of the o-Ps lifetime in the crystalline state are briefly discussed.

  10. Measurement of the Lifetime Difference in the Bs0 System

    Microsoft Academic Search

    V. M. Abazov; B. Abbott; M. Abolins; B. S. Acharya; M. Adams; T. Adams; M. Agelou; J.-L. Agram; S. H. Ahn; M. Ahsan; G. D. Alexeev; G. Alkhazov; A. Alton; G. Alverson; G. A. Alves; M. Anastasoaie; T. Andeen; S. Anderson; B. Andrieu; Y. Arnoud; M. Arov; A. Askew; B. Åsman; A. C. S. Assis Jesus; O. Atramentov; C. Autermann; C. Avila; F. Badaud; A. Baden; L. Bagby; B. Baldin; P. W. Balm; P. Banerjee; S. Banerjee; E. Barberis; P. Bargassa; P. Baringer; C. Barnes; J. Barreto; J. F. Bartlett; U. Bassler; D. Bauer; A. Bean; S. Beauceron; M. Begalli; M. Begel; A. Bellavance; S. B. Beri; G. Bernardi; R. Bernhard; I. Bertram; M. Besançon; R. Beuselinck; V. A. Bezzubov; P. C. Bhat; V. Bhatnagar; M. Binder; C. Biscarat; K. M. Black; I. Blackler; G. Blazey; F. Blekman; S. Blessing; D. Bloch; U. Blumenschein; A. Boehnlein; O. Boeriu; T. A. Bolton; F. Borcherding; G. Borissov; K. Bos; T. Bose; A. Brandt; R. Brock; G. Brooijmans; A. Bross; N. J. Buchanan; D. Buchholz; M. Buehler; V. Buescher; S. Burdin; S. Burke; T. H. Burnett; E. Busato; C. P. Buszello; J. M. Butler; J. Cammin; S. Caron; W. Carvalho; B. C. K. Casey; N. M. Cason; H. Castilla-Valdez; S. Chakrabarti; D. Chakraborty; K. M. Chan; A. Chandra; D. Chapin; F. Charles; E. Cheu; D. K. Cho; S. Choi; B. Choudhary; T. Christiansen; L. Christofek; D. Claes; B. Clément; C. Clément; Y. Coadou; M. Cooke; W. E. Cooper; D. Coppage; M. Corcoran; A. Cothenet; M.-C. Cousinou; B. Cox; S. Crépé-Renaudin; D. Cutts; H. da Motta; M. Das; B. Davies; G. Davies; G. A. Davis; K. de; P. de Jong; S. J. de Jong; E. de La Cruz-Burelo; C. de Oliveira Martins; S. Dean; J. D. Degenhardt; F. Déliot; M. Demarteau; R. Demina; P. Demine; D. Denisov; S. P. Denisov; S. Desai; H. T. Diehl; M. Diesburg; M. Doidge; H. Dong; S. Doulas; L. V. Dudko; L. Duflot; S. R. Dugad; A. Duperrin; J. Dyer; A. Dyshkant; M. Eads; D. Edmunds; T. Edwards; J. Ellison; J. Elmsheuser; V. D. Elvira; S. Eno; P. Ermolov; O. V. Eroshin; J. Estrada; H. Evans; A. Evdokimov; V. N. Evdokimov; J. Fast; S. N. Fatakia; L. Feligioni; A. V. Ferapontov; T. Ferbel; F. Fiedler; F. Filthaut; W. Fisher; H. E. Fisk; I. Fleck; M. Fortner; H. Fox; S. Fu; S. Fuess; T. Gadfort; C. F. Galea; E. Gallas; E. Galyaev; C. Garcia; A. Garcia-Bellido; J. Gardner; V. Gavrilov; A. Gay; P. Gay; D. Gelé; R. Gelhaus; K. Genser; C. E. Gerber; Y. Gershtein; D. Gillberg; G. Ginther; T. Golling; N. Gollub; B. Gómez; K. Gounder; A. Goussiou; P. D. Grannis; S. Greder; H. Greenlee; Z. D. Greenwood; E. M. Gregores; Ph. Gris; J.-F. Grivaz; L. Groer; S. Grünendahl; M. W. Grünewald; S. N. Gurzhiev; G. Gutierrez; P. Gutierrez; A. Haas; N. J. Hadley; S. Hagopian; I. Hall; R. E. Hall; C. Han; L. Han; K. Hanagaki; K. Harder; A. Harel; R. Harrington; J. M. Hauptman; R. Hauser; J. Hays; T. Hebbeker; D. Hedin; J. M. Heinmiller; A. P. Heinson; U. Heintz; C. Hensel; G. Hesketh; M. D. Hildreth; R. Hirosky; J. D. Hobbs; B. Hoeneisen; M. Hohlfeld; S. J. Hong; R. Hooper; P. Houben; Y. Hu; J. Huang; V. Hynek; I. Iashvili; R. Illingworth; A. S. Ito; S. Jabeen; M. Jaffré; S. Jain; V. Jain; K. Jakobs; A. Jenkins; R. Jesik; K. Johns; M. Johnson; A. Jonckheere; P. Jonsson; A. Juste; D. Käfer; S. Kahn; E. Kajfasz; A. M. Kalinin; J. Kalk; D. Karmanov; J. Kasper; I. Katsanos; D. Kau; R. Kaur; R. Kehoe; S. Kermiche; S. Kesisoglou; A. Khanov; A. Kharchilava; Y. M. Kharzheev; H. Kim; T. J. Kim; B. Klima; J. M. Kohli; J.-P. Konrath; M. Kopal; V. M. Korablev; J. Kotcher; B. Kothari; A. Koubarovsky; A. V. Kozelov; J. Kozminski; A. Kryemadhi; S. Krzywdzinski; Y. Kulik; A. Kumar; S. Kunori; A. Kupco; T. Kurca; J. Kvita; S. Lager; N. Lahrichi; G. Landsberg; J. Lazoflores; A.-C. Le Bihan; P. Lebrun; W. M. Lee; A. Leflat; F. Lehner; C. Leonidopoulos; J. Leveque; P. Lewis; J. Li; Q. Z. Li; J. G. R. Lima; D. Lincoln; S. L. Linn; J. Linnemann; V. V. Lipaev; R. Lipton; L. Lobo; A. Lobodenko; M. Lokajicek; A. Lounis; P. Love; H. J. Lubatti; L. Lueking; L. Luo; M. Lynker; A. L. Lyon; A. K. A. Maciel; R. J. Madaras; P. Mättig; C. Magass; A. Magerkurth; A.-M. Magnan; N. Makovec; P. K. Mal; H. B. Malbouisson; S. Malik; V. L. Malyshev; H. S. Mao; Y. Maravin; M. Martens; S. E. K. Mattingly; A. A. Mayorov; R. McCarthy; R. McCroskey; D. Meder; A. Melnitchouk; A. Mendes; D. Mendoza; M. Merkin; K. W. Merritt; A. Meyer; J. Meyer; M. Michaut; H. Miettinen; J. Mitrevski; J. Molina; N. K. Mondal; R. W. Moore; T. Moulik; G. S. Muanza; M. Mulders; L. Mundim; Y. D. Mutaf; E. Nagy; M. Naimuddin; M. Narain; N. A. Naumann; H. A. Neal; J. P. Negret; S. Nelson; P. Neustroev; C. Noeding; A. Nomerotski; S. F. Novaes; T. Nunnemann; E. Nurse; V. O'Dell; D. C. O'Neil; V. Oguri; N. Oliveira; N. Oshima; G. J. Otero Y Garzón; P. Padley; N. Parashar; S. K. Park; J. Parsons; R. Partridge; N. Parua; A. Patwa; G. Pawloski; P. M. Perea; E. Perez; P. Pétroff; M. Petteni; R. Piegaia; M.-A. Pleier

    2005-01-01

    We present a study of the decay Bs0-->J\\/psivarphi. We obtain the CP-odd fraction in the final state at time zero, R?=0.16±0.10(stat)±0.02(syst), the average lifetime of the (Bs0, Bmacr s0) system, tau¯(Bs0)=1.39-0.16+0.13(stat)-0.02+0.01(syst)ps, and the relative width difference between the heavy and light mass eigenstates, DeltaGamma\\/Gamma¯?(GammaL-GammaH)\\/Gamma¯=0.24-0.38+0.28(stat)-0.04+0.03(syst). With the additional constraint from the world average of the Bs0 lifetime measurements using semileptonic decays,

  11. The ``accumulation effect'' of positrons in the stack of foils, detected by measurements of the positron implantation profile

    NASA Astrophysics Data System (ADS)

    Dryzek, Jerzy; Siemek, Krzysztof

    2013-12-01

    The profiles of positrons implanted from the radioactive source 22Na into a stack of foils and plates are the subject of our experimental and theoretical studies. The measurements were performed using the depth scanning of positron implantation profile method, and the theoretical calculations using the phenomenological multi-scattering model (MSM). Several stacks consisting of silver, gold and aluminum foils, and titanium and germanium plates were investigated. We notice that the MSM describes well the experimental profiles; however when the stack consisting of silver and gold foils, the backscattering and linear absorption coefficients differ significantly from those reported in the literature. We suggest the energy dependency of the backscattering coefficient for silver and gold. In the stacks which comprise titanium and germanium plates, there were observed the features, which indicate the presence of the "accumulation effect" in the experimental implantation profile. This effect was previously detected in implantation profiles in Monte Carlo simulations using the GEANT4 tool kit, and it consists in higher localization of positrons close the interface. We suppose that this effect can be essential for positron annihilation in any heterogeneous materials.

  12. Measurements of ultracold neutron lifetimes in solid deuterium

    E-print Network

    C. L. Morris; J. M. Anaya; T. J. Bowles; B. W. Filippone; P. Geltenbort; R. E. Hill; M. Hino; S. Hoedl; G. E. Hogan; T. M. Ito; T. Kawai; K. Kirch; S. K. Lamoreaux; C. -Y. Liu; M. Makela; L. J. Marek; J. W. Martin; R. N. Mortensen; A. Pichlmaier; A. Saunders; S. J. Seestrom; D. Smith; W. Teasdale; B. Tipton; M. Utsuro; A. R. Young; J. Yuan

    2001-09-28

    We present the first measurements of the survival time of ultracold neutrons (UCNs) in solid deuterium SD2. This critical parameter provides a fundamental limitation to the effectiveness of superthermal UCN sources that utilize solid ortho-deuterium as the source material. Superthermal UCN sources offer orders of magnitude improvement in the available densities of UCNs, and are of great importance to fundamental particle-physics experiments such as searches for a static electric dipole moment and lifetime measurements of the free neutron. These measurements are performed utilizing a SD2 source coupled to a spallation source of neutrons, providing a demonstration of UCN production in this geometry and permitting systematic studies of the influence of thermal up-scatter and contamination with para-deuterium on the UCN survival time.

  13. The cosmic-ray positron and electron spectra measured by PAMELA

    NASA Astrophysics Data System (ADS)

    Bellotti, Roberto; Mocchiutti, Emiliano; Bianco, Andrea; Rossetto, Laura; Monaco, Alfonso

    2012-07-01

    The 15^{th} of June 2006, the satellite-borne experiment PAMELA was launched from the Baikonur cosmodrome and, since then, it is continuously taking data. The apparatus is optimized for the study of the cosmic-ray antimatter component in order to measure accurately the antiproton and positron energy spectra to investigate the nature of dark matter; in addition to these it is revealing protons, electrons and light nuclei. Positrons and electrons are a small but not negligible component of the cosmic radiation. They provide information regarding the origin and propagation of cosmic rays in the Galaxy. A particle classification system for the imaging calorimeter with a multivariate approach was adopted to significantly improve the positron selection. We will reported new measurements of the cosmic-ray electron and positron spectra and of the positron fraction, extending previously published PAMELA measurements up to 200 GeV.

  14. A method for measuring the energy spectrum of coincidence events in positron emission tomography

    Microsoft Academic Search

    Andrew L Goertzen; David B Stout; Christopher J Thompson

    2010-01-01

    Positron emission tomography (PET) system energy response is typically characterized in singles detection mode, yet there are situations in which the energy spectrum of coincidence events might be different than the spectrum measured in singles mode. Examples include imaging with isotopes that emit a prompt gamma in coincidence with a positron emission, imaging with low activity in a LSO\\/LYSO-based cameras,

  15. Lifetime measurements in the transitional nucleus 138Gd

    NASA Astrophysics Data System (ADS)

    Procter, M. G.; Cullen, D. M.; Ruotsalainen, P.; Braunroth, T.; Dewald, A.; Fransen, C.; Grahn, T.; Greenlees, P. T.; Hackstein, M.; Hauschild, K.; Jakobsson, U.; Jones, P. M.; Julin, R.; Juutinen, S.; Ketelhut, S.; Lopez-Martens, A.; Leino, M.; Litzinger, J.; Mason, P. J. R.; Nieminen, P.; Peura, P.; Rahkila, P.; Reed, M. W.; Rice, S.; Rinta-Antilla, S.; Rother, W.; Sandzelius, M.; Sarén, J.; Scholey, C.; Sorri, J.; Taylor, M. J.; Uusitalo, J.; Vitturi, A.; Shi, Y.; Xu, F. R.

    2011-08-01

    Lifetime measurements have been made in the ground-state band of the transitional nucleus 138Gd from coincidence recoil-distance Doppler-shift data. 138Gd nuclei were produced using the 106Cd (36Ar, 2p2n) reaction with a beam energy of 190 MeV. Reduced transition probabilities have been extracted from the lifetime data collected with the Köln plunger placed at the target position of the JUROGAM-II array. The B(E2) values have been compared with predictions from X(5) critical-point calculations, which describe the phase transition between vibrational and axially symmetric nuclear shapes, as well as with IBM-1 calculations at the critical point. While the excitation energies in 138Gd are consistent with X(5) predictions, the large uncertainties associated with the measured B(E2) values cannot preclude vibrational and rotational contributions to the low-lying structure of 138Gd. Although experimental knowledge for the low-lying ? and ?-vibrational bands in 138Gd is limited, potential-energy surface calculations suggest an increase in ? softness in the ground-state band. In order to more fully account for the effects of ? softness, the X(5) and IBM-1 calculations need to be extended to include the ? degree of freedom for 138Gd.

  16. Secondary cosmic-ray electrons and positrons from 1 to 100 GeV in the upper atmosphere and interstellar space, and interpretation of a recent positron flux measurement

    NASA Technical Reports Server (NTRS)

    Orth, C. D.; Buffington, A.

    1976-01-01

    Secondary electron and positron fluxes generated in interstellar space and in the atmosphere from the decays of pions and kaons in inelastic nuclear interactions are calculated by Monte Carlo techniques for lepton energies in the range from 1 to 100 GeV and an assumed thickness of 10 g/sq cm or less for the interstellar or atmospheric material. A simple and accurate analytical model which summarizes the Monte Carlo results and identifies the essential parameters involved is developed and used to interpret a previous positron measurement. It is found that the thickness of interstellar and source material is about 4.3 g/sq cm for cosmic-ray positrons with energies exceeding 4 GeV, a result that is difficult to reconcile with recently proposed two-containment-volume propagation models which predict a thickness of 1.8 g/sq cm for the same energies on the basis of the energy dependence of the measured (Li+Be+B)/(C+O) ratio. It is shown that single-containment-volume (galactic) models invoking an energy-dependent leakage lifetime are compatible with the positron data, but lack a mechanism to explain the energy dependence.

  17. Apparatus for measuring minority carrier lifetimes in semiconductor materials

    DOEpatents

    Ahrenkiel, R.K.

    1999-07-27

    An apparatus for determining the minority carrier lifetime of a semiconductor sample includes a positioner for moving the sample relative to a coil. The coil is connected to a bridge circuit such that the impedance of one arm of the bridge circuit is varied as sample is positioned relative to the coil. The sample is positioned relative to the coil such that any change in the photoconductance of the sample created by illumination of the sample creates a linearly related change in the input impedance of the bridge circuit. In addition, the apparatus is calibrated to work at a fixed frequency so that the apparatus maintains a consistently high sensitivity and high linearly for samples of different sizes, shapes, and material properties. When a light source illuminates the sample, the impedance of the bridge circuit is altered as excess carriers are generated in the sample, thereby producing a measurable signal indicative of the minority carrier lifetimes or recombination rates of the sample. 17 figs.

  18. Evolution of the positron annihilation lifetime for ageing in {beta} phase Cu-Al-Ni-(Ti)-(Mn) shape memory alloys

    SciTech Connect

    Hurtado, I.; Van Humbeeck, J. [Katholieke Universiteit Leuven (Belgium). Dept. Metaalkunde en Toegepaste Materiaalkunde] [Katholieke Universiteit Leuven (Belgium). Dept. Metaalkunde en Toegepaste Materiaalkunde; Segers, D.; Dorikens-Vanpraet, L.; Dauwe, C. [Rijksuniversiteit Gent (Belgium). Vakgroep Subatomaire en Stralingsfysica] [Rijksuniversiteit Gent (Belgium). Vakgroep Subatomaire en Stralingsfysica

    1995-09-01

    During the last years, the positron annihilation technique has proven to be a sensitive tool for the characterization of phase transitions, and in particular of the martensitic transformation in Cu-based alloys. The differences in structure between the high temperature phase (cubic) and the martensite (monoclinic) produce distinctive positron annihilation characteristics which allow the determination of the transformation temperature range. In the present article the influence of these parameters on the positron annihilation characteristics of three Cu-Al-Ni shape memory alloys is discussed. Two of the chosen compositions contain Ti and Mn, which have been added to the ternary Cu-Al-Ni alloy in order to improve its mechanical properties. The effect of those elements has also been evaluated.

  19. Positron-gamma angular correlation measurements on the decays of 84Rb, 74As, 124I and 102Rh

    Microsoft Academic Search

    A. de Beer; J. H. Stuivenberg; B. Meindersma; J. Blok

    1969-01-01

    Positron-gamma angular correlations have been measured using a plastic scintillator to detect the positrons. The disturbance of the positron spectrum due to Compton scattering of the annihilation quanta in the plastic has been avoided by counting these quanta simultaneously in two large NaI(Tl) crystals. Measurements were performed on 2- --> 2+ nonunique first order forbidden transitions from the ground states

  20. First ?K atom lifetime and ?K scattering length measurements

    NASA Astrophysics Data System (ADS)

    Adeva, B.; Afanasyev, L.; Allkofer, Y.; Amsler, C.; Anania, A.; Aogaki, S.; Benelli, A.; Brekhovskikh, V.; Cechak, T.; Chiba, M.; Chliapnikov, P.; Ciocarlan, C.; Constantinescu, S.; Doskarova, P.; Drijard, D.; Dudarev, A.; Duma, M.; Dumitriu, D.; Fluerasu, D.; Gorin, A.; Gorchakov, O.; Gritsay, K.; Guaraldo, C.; Gugiu, M.; Hansroul, M.; Hons, Z.; Horikawa, S.; Iwashita, Y.; Karpukhin, V.; Kluson, J.; Kobayashi, M.; Kruglov, V.; Kruglova, L.; Kulikov, A.; Kulish, E.; Kuptsov, A.; Lamberto, A.; Lanaro, A.; Lednicky, R.; Mariñas, C.; Martincik, J.; Nemenov, L.; Nikitin, M.; Okada, K.; Olchevskii, V.; Pentia, M.; Penzo, A.; Plo, M.; Ponta, T.; Prusa, P.; Rappazzo, G.; Romero Vidal, A.; Ryazantsev, A.; Rykalin, V.; Saborido, J.; Schacher, J.; Sidorov, A.; Smolik, J.; Sugimoto, S.; Takeutchi, F.; Tauscher, L.; Trojek, T.; Trusov, S.; Urban, T.; Vrba, T.; Yazkov, V.; Yoshimura, Y.; Zhabitsky, M.; Zrelov, P.

    2014-07-01

    The results of a search for hydrogen-like atoms consisting of ??K± mesons are presented. Evidence for ?K atom production by 24 GeV/c protons from CERN PS interacting with a nickel target has been seen in terms of characteristic ?K pairs from their breakup in the same target (178 ± 49) as well as in terms of produced ?K atoms (653 ± 42). Using these results, the analysis yields a first value for the ?K atom lifetime of ? = (2.5-1.8+3.0) fs and a first measurement of the S-wave isospin-odd ?K scattering length | a0- | =1/3 |a1/2 -a3/2 | = (0.11-0.04+0.09) M?-1 (aI for isospin I).

  1. Measuring early or late dependence for bivariate lifetimes of twins.

    PubMed

    Scheike, Thomas H; Holst, Klaus K; Hjelmborg, Jacob B

    2015-04-01

    We consider data from the Danish twin registry and aim to study in detail how lifetimes for twin-pairs are correlated. We consider models where we specify the marginals using a regression structure, here Cox's regression model or the additive hazards model. The best known such model is the Clayton-Oakes model. This model can be extended in several directions. One extension is to allow the dependence parameter to depend on covariates. Another extension is to model dependence via piecewise constant cross-hazard ratio models. We show how both these models can be implemented for large sample data, and suggest a computational solution for obtaining standard errors for such models for large registry data. In addition we consider alternative models that have some computational advantages and with different dependence parameters based on odds ratios of the survival function using the Plackett distribution. We also suggest a way of assessing how and if the dependence is changing over time, by considering either truncated or right-censored versions of the data to measure late or early dependence. This can be used for formally testing if the dependence is constant, or decreasing/increasing. The proposed procedures are applied to Danish twin data to describe dependence in the lifetimes of the twins. Here we show that the early deaths are more correlated than the later deaths, and by comparing MZ and DZ associations we suggest that early deaths might be more driven by genetic factors. This conclusion requires models that are able to look at more local dependence measures. We further show that the dependence differs for MZ and DZ twins and appears to be the same for males and females, and that there are indications that the dependence increases over calendar time. PMID:25185657

  2. Nondestructive detection of fatigue damage in austenitic stainless steel by positron annihilation

    Microsoft Academic Search

    Petra Schaaff; Uwe Holzwarth

    2005-01-01

    Austenitic stainless steel specimens have been examined by positron-lifetime measurements at various stages until failure\\u000a during fatigue tests at constant stress or plastic strain amplitudes. A positron-source-detector assembly has been mounted\\u000a on the servohydraulic testing machines that allowed truly non-destructive positron annihilation studies without removing the\\u000a specimens from the load train. Positrons were generated by a 72Se\\/72 As source with

  3. Measurement of absolute elastic differential cross-sections for positron-methane scattering

    SciTech Connect

    Przybyla, D.A.; Dou, L.; Kwan, C.K. [and others

    1993-05-01

    We have measured absolute elastic differential cross-sections (DCS`s) for positrons scattered from methane over the energy range 6 to 200 eV at scattering angles from 30 to 135 degrees. We use a crossed beam experiment to obtain the DCS for electron-methane scattering at 20 eV which is then normalized at 90 degrees to the absolute measurements of Tanaka et al. This normalization factor is used to obtain absolute positron DCS`s from our relative positron DCS measurements. Our absolute DCS`s are in qualitative agreement with the calculations of Jain and Gianturco. Because of the similarity in shape between the total cross-section curves for positron-methane and positron-argon scattering, it is of interest to determine whether a resonance-like structure seen in the elastic DCS for positron-argon scattering at intermediate energies also appears in the DCS for positron-methane scattering. No such structure has yet been found.

  4. Cosmic-ray positron fraction measurement from 1 to 30 GeV with AMS-01

    E-print Network

    AMS-01 Collaboration

    2007-03-27

    A measurement of the cosmic ray positron fraction e+/(e+ + e-) in the energy range of 1-30 GeV is presented. The measurement is based on data taken by the AMS-01 experiment during its 10 day Space Shuttle flight in June 1998. A proton background suppression on the order of 10^6 is reached by identifying converted bremsstrahlung photons emitted from positrons.

  5. Cosmic-ray positron fraction measurement from 1 to 30 GeV with AMS-01

    E-print Network

    Aguilar, M; Allaby, James V; Alpat, B; Ambrosi, G; Anderhub, H; Ao, L; Arefev, A; Azzarello, P; Baldini, L; Basile, M; Barancourt, D; Barão, F; Barbier, G; Barreira, G; Battiston, R; Becker, R; Becker, U; Bellagamba, L; Bene, P; Berdugo, J; Berges, P; Bertucci, B; Biland, A; Blasko, S; Bölla, G; Boschini, M; Bourquin, M; Brocco, L; Bruni, G; Buénerd, M; Burger, J D; Burger, W J; Cai, X D; Camps, C; Cannarsa, P; Capell, M; Cardano, F; Casadei, D; Casaus, J; Castellini, G; Chang, Y H; Chen, H F; Chen, H S; Chen, Z G; Chernoplekov, N A; Tzi Hong Chiueh; Cho, K; Choi, M J; Choi, Y Y; Cindolo, F; Commichau, V; Contin, A; Cortina, E; Cristinziani, M; Dai, T S; Delgado, C; Difalco, S; Djambazov, L; D'Antone, I; Dong, Z R; Emonet, P; Engelberg, J; Eppling, F J; Eronen, T; Esposito, G; Extermann, P; Favier, Jean; Fiandrini, E; Fisher, P H; Flügge, G; Fouque, N; Galaktionov, Yu; Gast, H; Gervasi, M; Giusti, P; Grandi, D; Grimm, O; Gu, W Q; Hangarter, K; Hasan, A; Hermel, V; Hofer, H; Hungerford, W; Jongmanns, M; Karlamaa, K; Karpinski, W; Kenney, G; Kim, D H; Kim, G N; Kim, K S; Kim, M Y; Klimentov, A; Kossakowski, R; Kounine, A; Koutsenko, V F; Kraeber, M; Laborie, G; Laitinen, T; Lamanna, G; Lanciotti, E; Laurenti, G; Lebedev, A; Lechanoine-Leluc, C; Lee, M W; Lee, S C; Levi, G; Liu, C L; Liu, H T; Lu, G; Lü, Y S; Lübelsmeyer, K; Luckey, D; Lustermann, W; Maña, C; Margotti, A; Mayet, F; McNeil, R R; Meillon, B; Menichelli, M; Mihul, A; Mujunen, A; Oliva, A; Olzem, J; Palmonari, F; Park, H B; Park, W H; Pauluzzi, M; Pauss, F; Perrin, E; Pesci, A; Pevsner, A; Pilo, F; Pimenta, M; Plyaskin, V; Pozhidaev, V; Pohl, M; Produit, N; Rancoita, P G; Rapin, D; Raupach, F; Ren, D; Ren, Z; Ribordy, M; Richeux, J P; Riihonen, E; Ritakari, J; Ro, S; Röser, U; Rossin, C; Sagdeev, R; Santos, D; Sartorelli, G; Sbarra, C; Schael, S; Schultzvon Dratzig, A; Schwering, G; Seo, E S; Shin, J W; Shoumilov, E; Shoutko, V; Siedenburg, T; Siedling, R; Son, D; Song, T; Spinella, F; Steuer, M; Sun, G S; Suter, H; Tang, X W; Ting, Samuel C C; Ting, S M; Tornikoski, M; Torsti, J; Trumper, J; Ulbricht, J; Urpo, S; Valtonen, E; Vandenhirtz, J; Velikhov, E P; Verlaat, B; Vetlitskii, I; Vezzu, F; Vialle, J P; Viertel, G; Vite, D; Von Gunten, H; Waldmeier-Wicki, S; Wallraff, W; Wang, B C; Wang, J Z; Wiik, K; Williams, C; Wu, S X; Xia, P C; Xu, S; Yan, J L; Yan, L G; Yang, C G; Yang, J; Yang, M; Ye, S W; Xu, Z Z; Zhang, H Y; Zhang, Z P; Zhao, D X; Zhou, Y; Zhu, G Y; Zhu, W Z; Zhuang, H L; Zichichi, A; Zimmermann, B; Zuccon, P

    2007-01-01

    A measurement of the cosmic ray positron fraction e+/(e+ + e-) in the energy range of 1-30 GeV is presented. The measurement is based on data taken by the AMS-01 experiment during its 10 day Space Shuttle flight in June 1998. A proton background suppression on the order of 10^6 is reached by identifying converted bremsstrahlung photons emitted from positrons.

  6. Cosmic-ray positron fraction measurement from 1 to 30 GeV with AMS-01

    NASA Astrophysics Data System (ADS)

    AMS-01 Collaboration; Aguilar, M.; Alcaraz, J.; Allaby, J.; Alpat, B.; Ambrosi, G.; Anderhub, H.; Ao, L.; Arefiev, A.; Azzarello, P.; Baldini, L.; Basile, M.; Barancourt, D.; Barao, F.; Barbier, G.; Barreira, G.; Battiston, R.; Becker, R.; Becker, U.; Bellagamba, L.; Béné, P.; Berdugo, J.; Berges, P.; Bertucci, B.; Biland, A.; Blasko, S.; Boella, G.; Boschini, M.; Bourquin, M.; Brocco, L.; Bruni, G.; Buénerd, M.; Burger, J. D.; Burger, W. J.; Cai, X. D.; Camps, C.; Cannarsa, P.; Capell, M.; Cardano, F.; Casadei, D.; Casaus, J.; Castellini, G.; Chang, Y. H.; Chen, H. F.; Chen, H. S.; Chen, Z. G.; Chernoplekov, N. A.; Chiueh, T. H.; Cho, K.; Choi, M. J.; Choi, Y. Y.; Cindolo, F.; Commichau, V.; Contin, A.; Cortina-Gil, E.; Cristinziani, M.; Dai, T. S.; Delgado, C.; Difalco, S.; Djambazov, L.; D'Antone, I.; Dong, Z. R.; Emonet, P.; Engelberg, J.; Eppling, F. J.; Eronen, T.; Esposito, G.; Extermann, P.; Favier, J.; Fiandrini, E.; Fisher, P. H.; Flügge, G.; Fouque, N.; Galaktionov, Yu.; Gast, H.; Gervasi, M.; Giusti, P.; Grandi, D.; Grimm, O.; Gu, W. Q.; Hangarter, K.; Hasan, A.; Hermel, V.; Hofer, H.; Hungerford, W.; Jongmanns, M.; Karlamaa, K.; Karpinski, W.; Kenney, G.; Kim, D. H.; Kim, G. N.; Kim, K. S.; Kim, M. Y.; Klimentov, A.; Kossakowski, R.; Kounine, A.; Koutsenko, V.; Kraeber, M.; Laborie, G.; Laitinen, T.; Lamanna, G.; Lanciotti, E.; Laurenti, G.; Lebedev, A.; Lechanoine-Leluc, C.; Lee, M. W.; Lee, S. C.; Levi, G.; Liu, C. L.; Liu, H. T.; Lu, G.; Lu, Y. S.; Lübelsmeyer, K.; Luckey, D.; Lustermann, W.; Maña, C.; Margotti, A.; Mayet, F.; McNeil, R. R.; Meillon, B.; Menichelli, M.; Mihul, A.; Mujunen, A.; Oliva, A.; Olzem, J.; Palmonari, F.; Park, H. B.; Park, W. H.; Pauluzzi, M.; Pauss, F.; Perrin, E.; Pesci, A.; Pevsner, A.; Pilo, F.; Pimenta, M.; Plyaskin, V.; Pojidaev, V.; Pohl, M.; Produit, N.; Rancoita, P. G.; Rapin, D.; Raupach, F.; Ren, D.; Ren, Z.; Ribordy, M.; Richeux, J. P.; Riihonen, E.; Ritakari, J.; Ro, S.; Roeser, U.; Rossin, C.; Sagdeev, R.; Santos, D.; Sartorelli, G.; Sbarra, C.; Schael, S.; Schultz von Dratzig, A.; Schwering, G.; Seo, E. S.; Shin, J. W.; Shoumilov, E.; Shoutko, V.; Siedenburg, T.; Siedling, R.; Son, D.; Song, T.; Spinella, F.; Steuer, M.; Sun, G. S.; Suter, H.; Tang, X. W.; Ting, Samuel C. C.; Ting, S. M.; Tornikoski, M.; Torsti, J.; Trümper, J.; Ulbricht, J.; Urpo, S.; Valtonen, E.; Vandenhirtz, J.; Velikhov, E.; Verlaat, B.; Vetlitsky, I.; Vezzu, F.; Vialle, J. P.; Viertel, G.; Vité, D.; von Gunten, H.; Waldmeier Wicki, S.; Wallraff, W.; Wang, B. C.; Wang, J. Z.; Wiik, K.; Williams, C.; Wu, S. X.; Xia, P. C.; Xu, S.; Yan, J. L.; Yan, L. G.; Yang, C. G.; Yang, J.; Yang, M.; Ye, S. W.; Xu, Z. Z.; Zhang, H. Y.; Zhang, Z. P.; Zhao, D. X.; Zhou, Y.; Zhu, G. Y.; Zhu, W. Z.; Zhuang, H. L.; Zichichi, A.; Zimmermann, B.; Zuccon, P.

    2007-03-01

    A measurement of the cosmic ray positron fraction e/(e+e) in the energy range of 1 30 GeV is presented. The measurement is based on data taken by the AMS-01 experiment during its 10 day Space Shuttle flight in June 1998. A proton background suppression on the order of 106 is reached by identifying converted bremsstrahlung photons emitted from positrons.

  7. Cosmic-ray positron fraction measurement from 1 to 30 GeV with AMS01

    Microsoft Academic Search

    M. Aguilar; J. Alcaraz; B. Alpat; G. Ambrosi; H. Anderhub; L. Ao; A. Arefiev; P. Azzarello; L. Baldini; M. Basile; D. Barancourt; F. Barao; G. Barbier; G. Barreira; R. Battiston; U. Becker; L. Bellagamba; P. Béné; J. Berdugo; P. Berges; B. Bertucci; A. Biland; S. Blasko; G. Boella; M. Boschini; L. Brocco; G. Bruni; M. Buénerd; J. D. Burger; W. J. Burger; X. D. Cai; C. Camps; P. Cannarsa; M. Capell; F. Cardano; D. Casadei; J. Casaus; G. Castellini; Y. H. Chang; Y. H. Chang; H. S. Chen; Z. G. Chen; N. A. Chernoplekov; Tzi Hong Chiueh; K. Cho; M. J. Choi; Y. Y. Choi; F. Cindolo; V. Commichau; A. Contin; E. Cortina-Gil; M. Cristinziani; T. S. Dai; C. Delgado; S. Difalco; L. Djambazov; I. D'Antone; Z. R. Dong; P. Emonet; J. Engelberg; F. J. Eppling; T. Eronen; G. Esposito; P. Extermann; Jean Favier; E. Fiandrini; P. H. Fisher; G. Flügge; N. Fouque; Yu. Galaktionov; H. Gast; M. Gervasi; P. Giusti; D. Grandi; O. Grimm; W. Q. Gu; K. Hangarter; A. Hasan; V. Hermel; H. Hofer; W. Hungerford; M. Jongmanns; K. Karlamaa; W. Karpinski; G. Kenney; D. H. Kim; G. N. Kim; K. S. Kim; M. Y. Kim; A. Klimentov; R. Kossakowski; A. Kounine; V F Koutsenko; M. Kraeber; G. Laborie; T. Laitinen; G. Lamanna; E. Lanciotti; G. Laurenti; A. Lebedev; C. Lechanoine-Leluc; M. W. Lee; S. C. Lee; G. Levi; C. L. Liu; H. T. Liu; G. Lu; Y. S. Lu; K. Lübelsmeyer; D. Luckey; W. Lustermann; C. Maña; A. Margotti; F. Mayet; R. R. McNeil; B. Meillon; M. Menichelli; A. Mihul; A. Mujunen; A. Oliva; J. Olzem; F. Palmonari; H. B. Park; W. H. Park; M. Pauluzzi; F. Pauss; E. Perrin; A. Pesci; A. Pevsner; F. Pilo; M. Pimenta; V. Plyaskin; V Pozhidaev; M. Pohl; N. Produit; P. G. Rancoita; D. Rapin; F. Raupach; D. Ren; Z. Ren; M. Ribordy; J. P. Richeux; E. Riihonen; J. Ritakari; S. Ro; U. Roeser; C. Rossin; R. Sagdeev; D. Santos; G. Sartorelli; C. Sbarra; S. Schael; A. Schultz von Dratzig; G. Schwering; E. S. Seo; J. W. Shin; E. Shoumilov; V. Shoutko; T. Siedenburg; R. Siedling; D. Son; T. Song; F. Spinella; M. Steuer; G. S. Sun; H. Suter; X. W. Tang; Samuel C. C. Ting; S. M. Ting; M. Tornikoski; J. Torsti; J. Trümper; J. Ulbricht; S. Urpo; E. Valtonen; J. Vandenhirtz; E P Velikhov; B. Verlaat; I Vetlitskii; F. Vezzu; J. P. Vialle; G. Viertel; D. Vité; H. Von Gunten; S. Waldmeier Wicki; W. Wallraff; B. C. Wang; J. Z. Wang; K. Wiik; C. Williams; S. X. Wu; P. C. Xia; S. Xu; J. L. Yan; J. L. Yan; C. G. Yang; J. Yang; M. Yang; S. W. Ye; Z. Z. Xu; H. Y. Zhang; Z. P. Zhang; D. X. Zhao; Y. Zhou; G. Y. Zhu; W. Z. Zhu; H. L. Zhuang; A. Zichichi; B. Zimmermann; P. Zuccon

    2007-01-01

    A measurement of the cosmic ray positron fraction e+\\/(e++e?) in the energy range of 1–30 GeV is presented. The measurement is based on data taken by the AMS-01 experiment during its 10 day Space Shuttle flight in June 1998. A proton background suppression on the order of 106 is reached by identifying converted bremsstrahlung photons emitted from positrons.

  8. Local Measurement of Fuel Energy Deposition and Heat Transfer Environment During Fuel Lifetime Using Controlled Calorimetry

    SciTech Connect

    Don W. Miller; Andrew Kauffmann; Eric Kreidler; Dongxu Li; Hanying Liu; Daniel Mills; Thomas D. Radcliff; Joseph Talnagi

    2001-12-31

    A comprehensive description of the accomplishments of the DOE grant titled, ''Local Measurement of Fuel Energy Deposition and Heat Transfer Environment During Fuel Lifetime using Controlled Calorimetry''.

  9. Microstructural Characterization of Polymers with Positrons

    NASA Technical Reports Server (NTRS)

    Singh, Jag J.

    1997-01-01

    Positrons provide a versatile probe for monitoring microstructural features of molecular solids. In this paper, we report on positron lifetime measurements in two different types of polymers. The first group comprises polyacrylates processed on earth and in space. The second group includes fully-compatible and totally-incompatible Semi-Interpenetrating polymer networks of thermosetting and thermoplastic polyimides. On the basis of lifetime measurements, it is concluded that free volumes are a direct reflection of physical/electromagnetic properties of the host polymers.

  10. A measurement of cosmic-ray positron and negatron spectra between 50 and 800 MV

    NASA Technical Reports Server (NTRS)

    Daugherty, J. K.; Hartman, R. C.; Schmidt, P. J.

    1975-01-01

    A balloon-borne spark chamber magnetic spectrometer has been used to measure the spectra of cosmic-ray positrons and negatrons at energies between 50 and 800 MV. The data reported here were obtained during two flights from Fort Churchill, Manitoba, in July 1972. The present results indicate that the dominance of negatrons from primary sources, found in earlier experiments above 200 MV, extends down to at least 50 MV. Solar modulation of the positron component is found to be consistent with that of the total electron spectrum, assuming that the positron component is entirely attributable to collisions between cosmic-ray nuclei and the interstellar gas.

  11. Lifetime measurements in $^{63}$Co and $^{65}$Co

    E-print Network

    A. Dijon; E. Clément; G. De France; P. Van Isacker; J. Ljungvall; A. Görgen; A. Obertelli; W. Korten; A. Gadea; L. Gaudefroy; M. Hackstein; D. Mengoni; Th. Pissulla; F. Recchia; M. Rejmund; W. Rother; E. Sahin; C. Schmitt; A. Shrivastava; J. J. Valiente-Dobon; K. O. Zell; M. Zielinska

    2011-06-14

    Lifetimes of the $9/2^-_1$ and $3/2^-_1$ states in $^{63}$Co and the $9/2^-_1$ state in $^{65}$Co were measured using the recoil distance Doppler shift and the differential decay curve methods. The nuclei were populated by multi-nucleon transfer reactions in inverse kinematics. Gamma rays were measured with the EXOGAM Ge array and the recoiling fragments were fully identified using the large-acceptance VAMOS spectrometer. The E2 transition probabilities from the $3/2^-_1$ and $9/2^-_1$ states to the $7/2^-$ ground state could be extracted in $^{63}$Co as well as an upper limit for the $9/2^-_1\\rightarrow7/2^-_1$ $B$(E2) value in $^{65}$Co. The experimental results were compared to large-scale shell-model calculations in the $pf$ and $pfg_{9/2}$ model spaces, allowing to draw conclusions on the single-particle or collective nature of the various states.

  12. Accurate Alternative Measurements for Female Lifetime Reproductive Success in Drosophila melanogaster

    PubMed Central

    Nguyen, Trinh T. X.; Moehring, Amanda J.

    2015-01-01

    Fitness is an individual’s ability to survive and reproduce, and is an important concept in evolutionary biology. However, accurately measuring fitness is often difficult, and appropriate fitness surrogates need to be identified. Lifetime reproductive success, the total progeny an organism can produce in their lifetime, is thought to be a suitable proxy for fitness, but the measure of an organism’s reproductive output across a lifetime can be difficult or impossible to obtain. Here we demonstrate that the short-term measure of reproductive success across five days provides a reasonable prediction of an individual's total lifetime reproductive success in Drosophila melanogaster. However, the lifetime reproductive success of a female that has only mated once is not correlated to the lifetime reproductive success of a female that is allowed to mate multiple times, demonstrating that these measures should not serve as surrogates nor be used to make inferences about one another. PMID:26125633

  13. Measurements of aperture and beam lifetime using movable beam scrapers in Indus-2 electron storage ring

    NASA Astrophysics Data System (ADS)

    Kumar, Pradeep; Ghodke, A. D.; Karnewar, A. K.; Holikatti, A. C.; Yadav, S.; Puntambekar, T. A.; Singh, G.; Singh, P.

    2013-12-01

    In this paper, the measurements of vertical and horizontal aperture which are available for stable beam motion in Indus-2 at beam energy 2.5 GeV using movable beam scrapers are presented. These beam scrapers are installed in one of the long straight sections in the ring. With the movement of beam scrapers towards the beam centre, the beam lifetime is measured. The beam lifetime data obtained from the movement of vertical and horizontal beam scrapers are analyzed. The contribution of beam loss due to beam-gas scattering (vacuum lifetime) and electron-electron scattering within a beam bunch (Touschek lifetime) is separated from the measured beam lifetime at different positions of the beam scrapers. Vertical and horizontal beam sizes at scrapers location are estimated from the scraper movement towards the beam centre in quantum lifetime limit and their values closely agree with measured value obtained using X-ray diagnostic beamline.

  14. Measurement of the Lifetime of the Bc± Meson in the Semileptonic Decay Channel

    Microsoft Academic Search

    V. M. Abazov; B. Abbott; M. Anastasoaie; B. S. Acharya; M. Adams; T. Adams; E. Aguilo; S. H. Ahn; M. Ahsan; G. D. Alexeev; G. Alkhazov; A. Alton; G. Alverson; G. A. Alves; L. S. Ancu; T. Andeen; S. Anderson; B. Andrieu; M. S. Anzelc; M. Aoki; Y. Arnoud; M. Arthaud; A. Askew; B. Åsman; A. C. S. Assis Jesus; O. Atramentov; C. Avila; F. Badaud; A. Baden; L. Bagby; B. Baldin; D. V. Bandurin; P. Banerjee; S. Banerjee; E. Barberis; A.-F. Barfuss; P. Bargassa; P. Baringer; J. F. Bartlett; U. Bassler; D. Bauer; S. Beale; A. Bean; M. Begalli; M. Begel; C. Belanger-Champagne; L. Bellantoni; A. Bellavance; J. A. Benitez; S. B. Beri; G. Bernardi; R. Bernhard; I. Bertram; M. Besançon; R. Beuselinck; V. A. Bezzubov; P. C. Bhat; V. Bhatnagar; C. Biscarat; G. Blazey; F. Blekman; S. Blessing; D. Bloch; K. Bloom; A. Boehnlein; D. Boline; T. A. Bolton; E. E. Boos; G. Brooijmans; T. Bose; A. Brandt; R. Brock; A. Bross; D. Brown; N. J. Buchanan; D. Buchholz; M. Buehler; V. Buescher; V. Bunichev; S. Burdin; S. Burke; T. H. Burnett; C. P. Buszello; J. M. Butler; P. Calfayan; S. Calvet; J. Cammin; W. Carvalho; B. C. K. Casey; H. Castilla-Valdez; S. Chakrabarti; D. Chakraborty; K. M. Chan; A. Chandra; F. Charles; E. Cheu; F. Chevallier; D. K. Cho; S. Choi; B. Choudhary; L. Christofek; T. Christoudias; S. Cihangir; D. Claes; J. Clutter; M. Cooke; W. E. Cooper; M. Corcoran; F. Couderc; M.-C. Cousinou; S. Crépé-Renaudin; D. Cutts; M. Cwiok; H. da Motta; A. Das; G. Davies; K. de; J. D. Degenhardt; E. de La Cruz-Burelo; C. de Oliveira Martins; F. Déliot; M. Demarteau; R. Demina; D. Denisov; S. P. Denisov; S. Desai; H. T. Diehl; M. Diesburg; A. Dominguez; H. Dong; L. V. Dudko; L. Duflot; S. R. Dugad; D. Duggan; A. Duperrin; J. Dyer; A. Dyshkant; M. Eads; D. Edmunds; J. Ellison; V. D. Elvira; Y. Enari; S. Eno; P. Ermolov; H. Evans; A. Evdokimov; V. N. Evdokimov; A. V. Ferapontov; T. Ferbel; F. Fiedler; F. Filthaut; W. Fisher; H. E. Fisk; M. Fortner; H. Fox; S. Fu; S. Fuess; T. Gadfort; C. F. Galea; E. Gallas; C. Garcia; A. Garcia-Bellido; V. Gavrilov; P. Gay; W. Geist; D. Gelé; C. E. Gerber; Y. Gershtein; D. Gillberg; G. Ginther; N. Gollub; B. Gómez; A. Goussiou; P. D. Grannis; H. Greenlee; Z. D. Greenwood; E. M. Gregores; G. Grenier; Ph. Gris; J.-F. Grivaz; A. Grohsjean; S. Grünendahl; M. W. Grünewald; F. Guo; J. Guo; G. Gutierrez; P. Gutierrez; A. Haas; N. J. Hadley; P. Haefner; S. Hagopian; J. Haley; I. Hall; R. E. Hall; L. Han; K. Harder; A. Harel; J. M. Hauptman; R. Hauser; J. Hays; T. Hebbeker; D. Hedin; J. G. Hegeman; A. P. Heinson; U. Heintz; C. Hensel; K. Herner; G. Hesketh; M. D. Hildreth; R. Hirosky; J. D. Hobbs; B. Hoeneisen; H. Hoeth; M. Hohlfeld; S. J. Hong; S. Hossain; P. Houben; Y. Hu; Z. Hubacek; V. Hynek; I. Iashvili; R. Illingworth; A. S. Ito; S. Jabeen; M. Jaffré; S. Jain; K. Jakobs; C. Jarvis; R. Jesik; K. Johns; C. Johnson; M. Johnson; A. Jonckheere; P. Jonsson; A. Juste; E. Kajfasz; J. M. Kalk; D. Karmanov; P. A. Kasper; I. Katsanos; D. Kau; V. Kaushik; R. Kehoe; S. Kermiche; N. Khalatyan; A. Khanov; A. Kharchilava; Y. M. Kharzheev; D. Khatidze; T. J. Kim; M. H. Kirby; M. Kirsch; B. Klima; J. M. Kohli; J.-P. Konrath; A. V. Kozelov; J. Kraus; D. Krop; T. Kuhl; A. Kumar; A. Kupco; T. Kurca; V. A. Kuzmin; J. Kvita; F. Lacroix; D. Lam; S. Lammers; G. Landsberg; P. Lebrun; W. M. Lee; A. Leflat; J. Lellouch; J. Leveque; J. Li; L. Li; Q. Z. Li; S. M. Lietti; J. G. R. Lima; D. Lincoln; J. Linnemann; V. V. Lipaev; R. Lipton; Y. Liu; Z. Liu; A. Lobodenko; M. Lokajicek; P. Love; H. J. Lubatti; R. Luna; A. L. Lyon; A. K. A. Maciel; D. Mackin; R. J. Madaras; P. Mättig; C. Magass; A. Magerkurth; P. K. Mal; H. B. Malbouisson; S. Malik; V. L. Malyshev; H. S. Mao; Y. Maravin; B. Martin; R. McCarthy; A. Melnitchouk; L. Mendoza; P. G. Mercadante; M. Merkin; K. W. Merritt; A. Meyer; J. Meyer; T. Millet; J. Mitrevski; R. K. Mommsen; N. K. Mondal; R. W. Moore; T. Moulik; G. S. Muanza; M. Mulhearn; O. Mundal; L. Mundim; E. Nagy; M. Naimuddin; M. Narain; N. A. Naumann; H. A. Neal; J. P. Negret; P. Neustroev; H. Nilsen; H. Nogima; S. F. Novaes; T. Nunnemann; V. O'Dell; D. C. O'Neil; G. Obrant; C. Ochando; D. Onoprienko; N. Oshima; N. Osman; J. Osta; R. Otec; G. J. Otero Y Garzón; M. Owen; P. Padley; M. Pangilinan; N. Parashar; S.-J. Park; S. K. Park; J. Parsons; R. Partridge; N. Parua; A. Patwa; G. Pawloski; B. Penning; M. Perfilov; K. Peters; Y. Peters; P. Pétroff; M. Petteni; R. Piegaia; J. Piper; M.-A. Pleier; P. L. M. Podesta-Lerma; V. M. Podstavkov; Y. Pogorelov; M.-E. Pol; P. Polozov; B. G. Pope; A. V. Popov; C. Potter; W. L. Prado da Silva; H. B. Prosper; S. Protopopescu; J. Qian; A. Quadt; B. Quinn; A. Rakitine; M. S. Rangel; K. Ranjan; P. N. Ratoff; P. Renkel; S. Reucroft; P. Rich; J. Rieger; M. Rijssenbeek; I. Ripp-Baudot; F. Rizatdinova; S. Robinson; R. F. Rodrigues; M. Rominsky; C. Royon

    2009-01-01

    Using approximately 1.3fb-1 of data collected by the D0 detector between 2002 and 2006, we measure the lifetime of the Bc± meson in the Bc±-->J\\/psimu±+X final state. A simultaneous unbinned likelihood fit to the J\\/psi+mu invariant mass and lifetime distributions yields a signal of 881±80(stat) candidates and a lifetime measurement of tau(Bc±)=0.448-0.036+0.038(stat)±0.032(syst)ps.

  15. Reemission Intensity and Energy Spectrum Measurements of Slow Positron Beams for Various Moderators

    Microsoft Academic Search

    Osamu Sueoka; Casten Makochekanwa; Satoshi Miyamoto

    2003-01-01

    Various characteristics of moderators for slow positron beam experiments using a 22Na source in non-ultra-high vacuum (UHV) were studied. Relative reemission intensities of slow positrons for various moderators: tungsten (W) annealed at various temperatures, rubbed by the polishing material SiC powder, etched chemically, covered by evaporation films of Cu metals, iridium (Ir) films and synthesized diamond films were relatively measured.

  16. Experimental arrangement for lifetime measurements based on beam-foil-laser excitation

    Microsoft Academic Search

    P. D. Dumont; H. P. Garnir; Y. Baudinet-Robinet; A. El Himdy

    1988-01-01

    A new experimental arrangement based on a two step excitation as resulting from foil and laser interaction for obtaining cascade-free lifetime measurements in neutral or ionized atoms is described. A test of the apparatus is realized by measuring the lifetimes of the 2p and 3p terms in H I. On leave from Département de Physique, Faculté des Sciences, université de

  17. Study of the MPD detector capabilities for electron-positron pair measurements at the NICA collider

    NASA Astrophysics Data System (ADS)

    Vasendina, V.; Jejer, V.; Kolesnikov, V.; Lobastov, S.; Musulmanbekov, G.; Tyapkin, I.; Zinchenko, A.

    2013-12-01

    One of the main tasks of the NICA/MPD physics program is a study of low-mass vector mesons ?, ?, ? by measuring their dileptonic decay channels. In this paper, the current status of simulations of electron-positron pair measurements in MPD is presented and the detector performance for such measurements is discussed.

  18. Measurement of positron spin polarization by using the Doppler broadening method

    NASA Astrophysics Data System (ADS)

    Nagai, Yasuyoshi; Nagashima, Yasuyuki; Kim, Jaehong; Itoh, Yoshiko; Hyodo, Toshio

    2000-08-01

    A new positron spin polarimeter based on the measurement of the Doppler broadening of annihilation radiation is described. The polarization is determined from the magnetic field dependence of the S-parameter of the Doppler broadening spectra for amorphous SiO 2. In order to examine the sensitivity of this polarimeter, the spin polarization of the positrons from a 22Na source is measured and compared with the value theoretically expected. The result is also compared with the polarization measured by using the angular correlation of annihilation radiation method.

  19. A chemical/microwave technique for the measurement of bulk minority carrier lifetime in silicon wafers

    NASA Technical Reports Server (NTRS)

    Luke, Keung L.; Cheng, Li-Jen

    1988-01-01

    A chemical/microwave technique for the measurement of bulk minority carrier lifetime in silicon wafers is described. This method consists of a wet chemical treatment (surface cleaning, oxidation in solution, and measurement in HF solution) to passivate the silicon surfaces, a laser diode array for carrier excitation, and a microwave bridge measuring system which is more sensitive than the microwave systems used previously for lifetime measurement. Representative experimental data are presented to demonstrate this technique. The result reveals that this method is useful for the determination of bulk lifetime of commercial silicon wafers.

  20. Net merit as a measure of lifetime profit: 2010 revision

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The 2010 revision of net merit (NM$) updates a number of key economic values as well as milk utilization statistics. Members of Project S-1040, Genetic Selection and Crossbreeding To Enhance Reproduction and Survival of Dairy Cattle, provided updated incomes and expenses used to estimate lifetime pr...

  1. Wavelength-resolved measurements of fluorescence lifetime of indocyanine green.

    PubMed

    Gerega, Anna; Zolek, Norbert; Soltysinski, Tomasz; Milej, Daniel; Sawosz, Piotr; Toczylowska, Beata; Liebert, Adam

    2011-06-01

    We study fluorescence lifetime of indocyanine green (ICG) using femtosecond laser and sensitive detection based on time-correlated single-photon counting. A time-resolved multichannel spectral system is constructed and applied for determination of the fluorescence lifetime of the ICG in different solvents. Emission properties of ICG in water, milk, and 1% intralipid solution are investigated. Fluorescence of the fluorophore of different concentrations (in a range of 1.7-160 ?M) dissolved in different solutions is excited by femtosecond pulses generated with the use of Ti:Sa laser tuned within the range of 740-790 nm. It is observed that fluorescence lifetime of ICG in water is 0.166 ± 0.02 ns and does not depend on excitation and emission wavelengths. We also show that for the diffusely scattering solvents (milk and intralipid), the lifetime may depend on the dye concentration (especially for large concentrations of ICG). This effect should be taken into account when analyzing changes in the mean time of arrival of fluorescence photons excited in ICG dissolved in such optically turbid media. PMID:21721831

  2. Reemission Intensity and Energy Spectrum Measurements of Slow Positron Beams for Various Moderators

    NASA Astrophysics Data System (ADS)

    Sueoka, Osamu; Makochekanwa, Casten; Miyamoto, Satoshi

    2003-09-01

    Various characteristics of moderators for slow positron beam experiments using a 22Na source in non-ultra-high vacuum (UHV) were studied. Relative reemission intensities of slow positrons for various moderators: tungsten (W) annealed at various temperatures, rubbed by the polishing material SiC powder, etched chemically, covered by evaporation films of Cu metals, iridium (Ir) films and synthesized diamond films were relatively measured. Measurements of the beam energy spectrum of reemitted positrons just after annealing and after a long time in use are presented. By measurement of the energy spectrum, the value of the positron work function for W was found to be 2.1± 0.3 eV. Intensity and spectrum studies for the ribbon, plate and mesh type W moderators were also carried out. An Ir moderator shows 20% stronger intensity than a W-ribbon moderator, but is not convenient for practical use. A W-mesh moderator is the best choice for gas scattering experiments in non-UHV. The scanning transmission microscope (STM) and atomic force microscope apparatus (AFM) were used to observe the surface state of the W moderator for slow positrons. The relationship between the surface state and the reemission intensity was analyzed in the atomic and sub-micron scales.

  3. A method to increase scintillation lifetime measurement rates using a multi-hit TDC

    Microsoft Academic Search

    W. W. Moses

    1992-01-01

    Summary form only. A method for using a modern TDC (time-to-digital converter) to increase the scintillation lifetime measurement rate by a factor of over 300 is discussed. It uses the delayed coincidence method, where a start photomultiplier tube (PMT) provides a signal synchronized to the excitation of the specimen and a stop PMT samples the resulting fluorescent lifetime spectrum. Typical

  4. Systematics associated with positronium fractions as measured with variable-energy positron beams

    SciTech Connect

    Schultz, P.J.; Lynn, K.G.; Jorch, H.H.

    1984-11-01

    Positronium fraction measurements using positron beams have been utilized to extract information about the diffusion properties of positrons as well as defect concentrations in the near surface region of materials under a variety of experimental conditions. Owing to this recent interest we have undertaken to study some of the systematics and uncertainties associated with measurements of the positronium fraction, f. We restrict our discussion to determinations of f based on the peak:total ratio of counting rates for a single detector, only briefly considering alternate ways of obtaining f. We conclude with several recommendations that should be of particular interest to practitioners in the field.

  5. Measurement of the Bc- meson lifetime in the decay Bc-?J/??-

    NASA Astrophysics Data System (ADS)

    Aaltonen, T.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bisello, D.; Bizjak, I.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Calamba, A.; Calancha, C.; Camarda, S.; Campanelli, M.; Campbell, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chung, W. H.; Chung, Y. S.; Ciocci, M. A.; Clark, A.; Clarke, C.; Compostella, G.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Cuevas, J.; Culbertson, R.; Dagenhart, D.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Dell'Orso, M.; Demortier, L.; Deninno, M.; Devoto, F.; d'Errico, M.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; D'Onofrio, M.; Donati, S.; Dong, P.; Dorigo, M.; Dorigo, T.; Ebina, K.; Elagin, A.; Eppig, A.; Erbacher, R.; Errede, S.; Ershaidat, N.; Eusebi, R.; Farrington, S.; Feindt, M.; Fernandez, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Funakoshi, Y.; Furic, I.; Gallinaro, M.; Garcia, J. E.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Giannetti, P.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Goldschmidt, N.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Halkiadakis, E.; Hamaguchi, A.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harr, R. F.; Hatakeyama, K.; Hays, C.; Heck, M.; Heinrich, J.; Herndon, M.; Hewamanage, S.; Hocker, A.; Hopkins, W.; Horn, D.; Hou, S.; Hughes, R. E.; Hurwitz, M.; Husemann, U.; Hussain, N.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kim, Y. J.; Kimura, N.; Kirby, M.; Klimenko, S.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Kruse, M.; Krutelyov, V.; Kuhr, T.; Kurata, M.; Kwang, S.; Laasanen, A. T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R. L.; Lannon, K.; Lath, A.; Latino, G.; LeCompte, T.; Lee, E.; Lee, H. S.; Lee, J. S.; Lee, S. W.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lin, C.-J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maeshima, K.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Martínez, M.; Mastrandrea, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Mondragon, M. N.; Moon, C. S.; Moore, R.; Morello, M. J.; Morlock, J.; Movilla Fernandez, P.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Neubauer, M. S.; Nielsen, J.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagan Griso, S.; Pagliarone, C.; Palencia, E.; Papadimitriou, V.; Paramonov, A. A.; Patrick, J.; Pauletta, G.; Paulini, M.; Paus, C.; Pellett, D. E.; Penzo, A.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Prokoshin, F.; Pranko, A.; Ptohos, F.; Punzi, G.; Rahaman, A.; Ramakrishnan, V.; Ranjan, N.; Redondo, I.; Renton, P.; Rescigno, M.; Riddick, T.; Rimondi, F.; Ristori, L.; Robson, A.; Rodrigo, T.; Rodriguez, T.; Rogers, E.; Rolli, S.; Roser, R.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Safonov, A.; Sakumoto, W. K.; Sakurai, Y.

    2013-01-01

    The lifetime of the Bc- meson is measured using 272 exclusive Bc-?J/?(??+?-)?- decays reconstructed in data from proton-antiproton collisions corresponding to an integrated luminosity of 6.7fb-1 recorded by the CDF II detector at the Fermilab Tevatron. The lifetime of the Bc- meson is measured to be ?(Bc-)=0.452±0.048(stat)±0.027(syst)ps. This is the first measurement of the Bc- meson lifetime in a fully reconstructed hadronic channel, and it agrees with previous results and has comparable precision.

  6. Precision measurement of the K S meson lifetime with the KLOE detector

    NASA Astrophysics Data System (ADS)

    Ambrosino, F.; Antonelli, A.; Antonelli, M.; Archilli, F.; Bencivenni, G.; Bini, C.; Bloise, C.; Bocchetta, S.; Bossi, F.; Branchini, P.; Capon, G.; Capussela, T.; Ceradini, F.; Ciambrone, P.; De Angelis, A.; De Lucia, E.; De Maria, M.; De Santis, A.; De Simone, P.; De Zorzi, G.; Denig, A.; Di Domenico, A.; Di Donato, C.; Di Micco, B.; Dreucci, M.; Felici, G.; Fiore, S.; Franzini, P.; Gatti, C.; Gauzzi, P.; Giovannella, S.; Graziani, E.; Jacewicz, M.; Kulikov, V.; Lee-Franzini, J.; Martini, M.; Massarotti, P.; Meola, S.; Miscetti, S.; Moulson, M.; Müller, S.; Murtas, F.; Napolitano, M.; Nguyen, F.; Palutan, M.; Passeri, A.; Patera, V.; Santangelo, P.; Sciascia, B.; Sibidanov, A.; Spadaro, T.; Taccini, C.; Tortora, L.; Valente, P.; Venanzoni, G.; Versaci, R.

    2011-03-01

    Using a large sample of pure, slow, short lived K 0 mesons collected with KLOE detector at DA?NE, we have measured the K S lifetime. From a fit to the proper time distribution we find ?( K S )=(89.562±0.029stat±0.043syst) ps. This is the most precise measurement to date of the short lived K 0 meson lifetime, in good agreement with the world average derived from previous measurements. We observe no dependence of the lifetime on the direction of the K S in galactic coordinates.

  7. The electron beam lifetime problem in HERA

    Microsoft Academic Search

    D. R. C. Kelly; W. Bialowons; R. Brinkmann; H. Ehrlichmann; J S Kouptsidis

    1995-01-01

    The electron beam lifetime in the HERA storage ring is not only uniformly lower than the positron beam lifetime, but the electron beam lifetime curves display complicated structures not present in the smoothly behaved positron beam lifetime curves. Summaries of characterising quantities are presented for large numbers of runs in 1993 and 1994, enabling the identification of trends in the

  8. Positronium formation and inhibition in binary ionic solid solutions of general formula Al (1 ? x) Cr ( x) K(SO 4) 2 · 12 H 2O: A positron annihilation lifetime and Doppler broadening spectroscopy study

    Microsoft Academic Search

    J. C. Machado; G. M. de Lima; F. C. Oliveira; I. M. Marzano

    2006-01-01

    Positron annihilation lifetime and Doppler broadening spectroscopies were applied in solid mixtures and solutions of AlK(SO4)2·12H2O and CrK(SO4)2·12H2O. For the solid solutions of the general formula Al(1?x)Cr(x)K(SO4)2·12H2O (x=Cr(III)), a strong inhibition of positronium formation is observed with increasing chromium complex concentration. In the solid mixtures, the positronium formation decreases linearly with CrK(SO4)2·12H2O concentration, while the positronium lifetime remains constant for

  9. Measurement of the positron diffusion constants in polycrystalline molybdenum by the observation of positronium negative ions

    NASA Astrophysics Data System (ADS)

    Suzuki, Takuji; Iida, Simpei; Yamashita, Takashi; Nagashima, Yasuyuki

    2015-06-01

    We have measured the positron diffusion constants in polycrystalline molybdenum by the observation of positronium negative ions (Ps-). The Ps- ions emitted from the sample surface coated with Na were accelerated. The ?-rays from the accelerated Ps- ions were Doppler- shifted and thus the signals of self-annihilation of the Ps- ions were isolated from those of self-annihilation of para-positronium (p-Ps) or pair-annihilation of positrons in the bulk. Clear and reliable values of the diffusion constants have been obtained.

  10. Measurement of the Bs(0) ? Ds-Ds+ and Bs(0) ? D-Ds+ effective lifetimes.

    PubMed

    Aaij, R; Adeva, B; Adinolfi, M; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; Anderlini, L; Anderson, J; Andreassen, R; Andreotti, M; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Badalov, A; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Batozskaya, V; Bauer, Th; Bay, A; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Borsato, M; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Calabrese, R; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carranza-Mejia, H; Carson, L; Carvalho Akiba, K; Casse, G; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cenci, R; Charles, M; Charpentier, Ph; Cheung, S-F; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Couturier, B; Cowan, G A; Craik, D C; Cruz Torres, M; Cunliffe, S; Currie, R; D'Ambrosio, C; Dalseno, J; David, P; David, P N Y; Davis, A; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Donleavy, S; Dordei, F; Dorosz, P; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Falabella, A; Färber, C; Farinelli, C; Farry, S; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fiorini, M; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furfaro, E; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garofoli, J; Garosi, P; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gianelle, A; Gibson, V; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grillo, L; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Hafkenscheid, T W; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hartmann, T; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Heß, M; Hicheur, A; Hill, D; Hoballah, M; Hombach, C; Hulsbergen, W; Hunt, P; Huse, T; Hussain, N; Hutchcroft, D; Hynds, D; Iakovenko, V; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jans, E; Jaton, P; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kaballo, M; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Kenyon, I R; Ketel, T; Khanji, B; Klaver, S; Kochebina, O; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucharczyk, M; Kudryavtsev, V; Kurek, K; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Liles, M; Lindner, R; Linn, C; Lionetto, F; Liu, B; Liu, G; Lohn, S; Longstaff, I; Lopes, J H; Lopez-March, N; Lowdon, P; Lu, H; Lucchesi, D; Luisier, J; Luo, H; Luppi, E; Lupton, O; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Manca, G; Mancinelli, G; Maratas, J; Marconi, U; Marino, P; Märki, R; Marks, J; Martellotti, G; Martens, A; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martins Tostes, D; Martynov, A; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Mazurov, A; McCann, M; McCarthy, J; McNab, A; McNulty, R; McSkelly, B; Meadows, B; Meier, F; Meissner, M; Merk, M; Milanes, D A; Minard, M-N; Molina Rodriguez, J; Monteil, S; Moran, D; Morandin, M; Morawski, P

    2014-03-21

    The first measurement of the effective lifetime of the B(s)(0) meson in the decay B(s)(0) ? Ds-Ds+ is reported using a proton-proton collision data set, corresponding to an integrated luminosity of 3 fb(-1), collected by the LHCb experiment. The measured value of the B(s)(0) ? Ds-Ds+ effective lifetime is 1.379 ± 0.026 ± 0.017 ps, where the uncertainties are statistical and systematic, respectively. This lifetime translates into a measurement of the decay width of the light B(s)(0) mass eigenstate of ?L = 0.725 ± 0.014 ± 0.009 ps(-1). The B(s)(0) lifetime is also measured using the flavor-specific B(s)(0)? D-Ds+ decay to be 1.52 ± 0.15 ± 0.01 ps. PMID:24702350

  11. Measurement of the ?[superscript 0 over subscript b] lifetime and mass in the ATLAS experiment

    E-print Network

    Taylor, Frank E.

    A measurement of the ?[superscript 0 over subscript b] lifetime and mass in the decay channel ?[superscript 0 over subscript b]?J/?(?[superscript +]?[superscript -])?[superscript 0](p?[superscript -]) is presented. The ...

  12. In Pursuit of Highly Accurate Atomic Lifetime Measurements of Multiply Charged Ions

    SciTech Connect

    Trabert, E

    2009-06-01

    Accurate atomic lifetime data are useful for terrestrial and astrophysical plasma diagnostics. At accuracies higher than those required for these applications, lifetime measurements test atomic structure theory in ways complementary to spectroscopic energy determinations. At the highest level of accuracy, the question arises whether such tests reach the limits of modern theory, a combination of quantum mechanics and QED, adn possibly point to physics beyond the Standard Model. If high-precision atomic lifetime measurements, especially on multiply charged ions, have not quite reached this high accuracy yet, then what is necessary to attain this goal?

  13. Measurement of Separate Cosmic-Ray Electron and Positron Spectra with the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Allafort, A.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Brogland, A. W.; Bouvier, A.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Ferrara, E. C.; Harding, A. K.; McEnery, J. E.

    2011-01-01

    We measured separate cosmic-ray electron and positron spectra with the Fermi Large Area Telescope. Because the instrument does not have an onboard magnet, we distinguish the two species by exploiting the Earth's shadow, which is offset in opposite directions for opposite charges due to the Earth's magnetic field. We estimate and subtract the cosmic-ray proton background using two different methods that produce consistent results. We report the electron-only spectrum, the positron-only spectrum, and the positron fraction between 20 GeV and 200 GeV, We confirm that the fraction rises with energy in the 20-100 GeV range and determine for the first time that it continues to rise between 100 and 200 GeV,

  14. Measurement of Separate Cosmic-Ray Electron and Positron Spectra with the Fermi Large Area Telescope

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Ajello, M.; Allafort, A.; Atwood, W. B.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Cutini, S.; de Angelis, A.; de Palma, F.; Dermer, C. D.; Digel, S. W.; Do Couto E Silva, E.; Drell, P. S.; Drlica-Wagner, A.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Fortin, P.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Germani, S.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grove, J. E.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Harding, A. K.; Hayashida, M.; Hughes, R. E.; Jóhannesson, G.; Johnson, A. S.; Kamae, T.; Katagiri, H.; Kataoka, J.; Knödlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Lemoine-Goumard, M.; Llena Garde, M.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohno, M.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Parent, D.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Reposeur, T.; Ritz, S.; Romani, R. W.; Roth, M.; Sadrozinski, H. F.-W.; Sbarra, C.; Schalk, T. L.; Sgrò, C.; Siskind, E. J.; Spandre, G.; Spinelli, P.; Strong, A. W.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Thayer, J. G.; Thayer, J. B.; Tibaldo, L.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; Waite, A. P.; Winer, B. L.; Wood, K. S.; Wood, M.; Yang, Z.; Zimmer, S.

    2012-01-01

    We measured separate cosmic-ray electron and positron spectra with the Fermi Large Area Telescope. Because the instrument does not have an onboard magnet, we distinguish the two species by exploiting Earth’s shadow, which is offset in opposite directions for opposite charges due to Earth’s magnetic field. We estimate and subtract the cosmic-ray proton background using two different methods that produce consistent results. We report the electron-only spectrum, the positron-only spectrum, and the positron fraction between 20 and 200 GeV. We confirm that the fraction rises with energy in the 20-100 GeV range. The three new spectral points between 100 and 200 GeV are consistent with a fraction that is continuing to rise with energy.

  15. Measurement of separate cosmic-ray electron and positron spectra with the fermi large area telescope.

    PubMed

    Ackermann, M; Ajello, M; Allafort, A; Atwood, W B; Baldini, L; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bouvier, A; Bregeon, J; Brigida, M; Bruel, P; Buehler, R; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cecchi, C; Charles, E; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Conrad, J; Cutini, S; de Angelis, A; de Palma, F; Dermer, C D; Digel, S W; do Couto E Silva, E; Drell, P S; Drlica-Wagner, A; Favuzzi, C; Fegan, S J; Ferrara, E C; Focke, W B; Fortin, P; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Germani, S; Giglietto, N; Giommi, P; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Grenier, I A; Grove, J E; Guiriec, S; Gustafsson, M; Hadasch, D; Harding, A K; Hayashida, M; Hughes, R E; Jóhannesson, G; Johnson, A S; Kamae, T; Katagiri, H; Kataoka, J; Knödlseder, J; Kuss, M; Lande, J; Latronico, L; Lemoine-Goumard, M; Llena Garde, M; Longo, F; Loparco, F; Lovellette, M N; Lubrano, P; Madejski, G M; Mazziotta, M N; McEnery, J E; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nakamori, T; Nolan, P L; Norris, J P; Nuss, E; Ohno, M; Ohsugi, T; Okumura, A; Omodei, N; Orlando, E; Ormes, J F; Ozaki, M; Paneque, D; Parent, D; Pesce-Rollins, M; Pierbattista, M; Piron, F; Pivato, G; Porter, T A; Rainò, S; Rando, R; Razzano, M; Razzaque, S; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Romani, R W; Roth, M; Sadrozinski, H F-W; Sbarra, C; Schalk, T L; Sgrò, C; Siskind, E J; Spandre, G; Spinelli, P; Strong, A W; Takahashi, H; Takahashi, T; Tanaka, T; Thayer, J G; Thayer, J B; Tibaldo, L; Tinivella, M; Torres, D F; Tosti, G; Troja, E; Uchiyama, Y; Usher, T L; Vandenbroucke, J; Vasileiou, V; Vianello, G; Vitale, V; Waite, A P; Winer, B L; Wood, K S; Wood, M; Yang, Z; Zimmer, S

    2012-01-01

    We measured separate cosmic-ray electron and positron spectra with the Fermi Large Area Telescope. Because the instrument does not have an onboard magnet, we distinguish the two species by exploiting Earth's shadow, which is offset in opposite directions for opposite charges due to Earth's magnetic field. We estimate and subtract the cosmic-ray proton background using two different methods that produce consistent results. We report the electron-only spectrum, the positron-only spectrum, and the positron fraction between 20 and 200 GeV. We confirm that the fraction rises with energy in the 20-100 GeV range. The three new spectral points between 100 and 200 GeV are consistent with a fraction that is continuing to rise with energy. PMID:22304252

  16. Measurement of separate cosmic-ray electron and positron spectra with the Fermi Large Area Telescope

    E-print Network

    Ackermann, M; Allafort, A; Baldini, L; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bouvier, A; Bregeon, J; Brigida, M; Bruel, P; Buehler, R; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cecchi, C; Charles, E; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Conrad, J; Cutini, S; de Angelis, A; de Palma, F; Dermer, C D; Digel, S W; Silva, E do Couto e; Drell, P S; Drlica-Wagner, A; Favuzzi, C; Fegan, S J; Ferrara, E C; Focke, W B; Fortin, P; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Germani, S; Giglietto, N; Giommi, P; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Grenier, I A; Grove, J E; Guiriec, S; Gustafsson, M; Hadasch, D; Harding, A K; Hayashida, M; Hughes, R E; Jóhannesson, G; Johnson, A S; Kamae, T; Katagiri, H; Kataoka, J; Knödlseder, J; Kuss, M; Lande, J; Latronico, L; Lemoine-Goumard, M; Garde, M Llena; Longo, F; Loparco, F; Lovellette, M N; Lubrano, P; Madejski, G M; Mazziotta, M N; McEnery, J E; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nakamori, T; Nolan, P L; Norris, J P; Nuss, E; Ohno, M; Ohsugi, T; Okumura, A; Omodei, N; Ormes, E Orlando J F; Ozaki, M; Paneque, D; Parent, D; Pesce-Rollins, M; Pierbattista, M; Piron, F; Pivato, G; Porter, T A; Rainò, S; Rando, R; Razzano, M; Razzaque, S; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Romani, R W; Roth, M; Sadrozinski, H F -W; Sbarra, C; Schalk, T L; Sgrò, C; Siskind, E J; Spandre, G; Spinelli, P; Strong, A W; Takahashi, H; Takahashi, T; Tanaka, T; Thayer, J G; Thayer, J B; Tibaldo, L; Tinivella, M; Torres, D F; Tosti, G; Troja, E; Uchiyama, Y; Usher, T L; Vandenbroucke, J; Vasileiou, V; Vianello, G; Vitale, V; Waite, A P; Winer, B L; Wood, K S; Wood, M; Yang, Z; Zimmer, S

    2011-01-01

    We measured separate cosmic-ray electron and positron spectra with the Fermi Large Area Telescope. Because the instrument does not have an onboard magnet, we distinguish the two species by exploiting the Earth's shadow, which is offset in opposite directions for opposite charges due to the Earth's magnetic field. We estimate and subtract the cosmic-ray proton background using two different methods that produce consistent results. We report the electron-only spectrum, the positron-only spectrum, and the positron fraction between 20 GeV and 200 GeV. We confirm that the fraction rises with energy in the 20--100 GeV range and determine for the first time that it continues to rise between 100 and 200 GeV.

  17. Measurement of separate cosmic-ray electron and positron spectra with the Fermi Large Area Telescope

    Microsoft Academic Search

    M. Ackermann; M. Ajello; A. Allafort; L. Baldini; G. Barbiellini; D. Bastieri; K. Bechtol; R. Bellazzini; B. Berenji; R. D. Blandford; E. D. Bloom; E. Bonamente; A. W. Borgland; A. Bouvier; J. Bregeon; M. Brigida; P. Bruel; R. Buehler; S. Buson; G. A. Caliandro; R. A. Cameron; P. A. Caraveo; J. M. Casandjian; C. Cecchi; E. Charles; A. Chekhtman; C. C. Cheung; J. Chiang; S. Ciprini; R. Claus; J. Cohen-Tanugi; J. Conrad; S. Cutini; A. de Angelis; F. de Palma; C. D. Dermer; S. W. Digel; E. do Couto e Silva; P. S. Drell; A. Drlica-Wagner; C. Favuzzi; S. J. Fegan; E. C. Ferrara; W. B. Focke; P. Fortin; Y. Fukazawa; S. Funk; P. Fusco; F. Gargano; D. Gasparrini; S. Germani; N. Giglietto; P. Giommi; F. Giordano; M. Giroletti; T. Glanzman; G. Godfrey; I. A. Grenier; J. E. Grove; S. Guiriec; M. Gustafsson; D. Hadasch; A. K. Harding; M. Hayashida; R. E. Hughes; G. Jóhannesson; A. S. Johnson; T. Kamae; H. Katagiri; J. Kataoka; J. Knödlseder; M. Kuss; J. Lande; L. Latronico; M. Lemoine-Goumard; M. Llena Garde; F. Longo; F. Loparco; M. N. Lovellette; P. Lubrano; G. M. Madejski; M. N. Mazziotta; J. E. McEnery; P. F. Michelson; W. Mitthumsiri; T. Mizuno; A. A. Moiseev; C. Monte; M. E. Monzani; A. Morselli; I. V. Moskalenko; S. Murgia; T. Nakamori; P. L. Nolan; J. P. Norris; E. Nuss; M. Ohno; T. Ohsugi; A. Okumura; N. Omodei; E. Orlando J. F. Ormes; M. Ozaki; D. Paneque; D. Parent; M. Pesce-Rollins; M. Pierbattista; F. Piron; G. Pivato; T. A. Porter; S. Rainò; R. Rando; M. Razzano; S. Razzaque; A. Reimer; O. Reimer; T. Reposeur; S. Ritz; R. W. Romani; M. Roth; H. F.-W. Sadrozinski; C. Sbarra; T. L. Schalk; C. Sgrò; E. J. Siskind; G. Spandre; P. Spinelli; A. W. Strong; H. Takahashi; T. Takahashi; T. Tanaka; J. G. Thayer; J. B. Thayer; L. Tibaldo; M. Tinivella; D. F. Torres; G. Tosti; E. Troja; Y. Uchiyama; T. L. Usher; J. Vandenbroucke; V. Vasileiou; G. Vianello; V. Vitale; A. P. Waite; B. L. Winer; K. S. Wood; M. Wood; Z. Yang; S. Zimmer

    2011-01-01

    We measured separate cosmic-ray electron and positron spectra with the Fermi Large Area Telescope. Because the instrument does not have an onboard magnet, we distinguish the two species by exploiting the Earth's shadow, which is offset in opposite directions for opposite charges due to the Earth's magnetic field. We estimate and subtract the cosmic-ray proton background using two different methods

  18. Electron Beam Polarization Measurement Using Touschek Lifetime Technique

    SciTech Connect

    Sun, Changchun; /Duke U., DFELL; Li, Jingyi; /Duke U., DFELL; Mikhailov, Stepan; /Duke U., DFELL; Popov, Victor; /Duke U., DFELL; Wu, Wenzhong; /Duke U., DFELL; Wu, Ying; /Duke U., DFELL; Chao, Alex; /SLAC; Xu, Hong-liang; /Hefei, NSRL; Zhang, Jian-feng; /Hefei, NSRL

    2012-08-24

    Electron beam loss due to intra-beam scattering, the Touschek effect, in a storage ring depends on the electron beam polarization. The polarization of an electron beam can be determined from the difference in the Touschek lifetime compared with an unpolarized beam. In this paper, we report on a systematic experimental procedure recently developed at Duke FEL laboratory to study the radiative polarization of a stored electron beam. Using this technique, we have successfully observed the radiative polarization build-up of an electron beam in the Duke storage ring, and determined the equilibrium degree of polarization and the time constant of the polarization build-up process.

  19. Lifetime measurements in an electrostatic ion beam trap using image charge monitoring

    SciTech Connect

    Rahinov, Igor; Toker, Yoni; Heber, Oded; Rappaport, Michael; Zajfman, Daniel [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, 76100 Rehovot (Israel); Strasser, Daniel [Institute of Chemistry, Hebrew University of Jerusalem, 91904 Jerusalem (Israel); Schwalm, Dirk [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, 76100 Rehovot (Israel); Max Planck Institute for Nuclear Physics, D-69117 Heidelberg (Germany)

    2012-03-15

    A technique for mass-selective lifetime measurements of keV ions in a linear electrostatic ion beam trap is presented. The technique is based on bunching the ions using a weak RF potential and non-destructive ion detection by a pick-up electrode. This method has no mass-limitation, possesses the advantage of inherent mass-selectivity, and offers a possibility of measuring simultaneously the lifetimes of different ion species with no need for prior mass-selection.

  20. Transcutaneous measurement of the arterial input function in positron emission tomography

    SciTech Connect

    Litton, J.E.; Eriksson, L. (Dept. of Clinical Neurophysiology, Dept. of Neuroradiology and Dept. of Psychiatry and Psychology, Karolinska Hospital , S-104 01 Stockholm (SE))

    1990-04-01

    Positron emission tomography (PET) provides a powerful tool in medical research. Biochemical function can be both precisely localized and quantitatively measured. To achieve reliable quantitation it is necessary to know the time course of activity concentration in the arterial blood during the measurement. In this study the arterial blood curve from the brachial artery is compared to the activity measured in the internal carotid artery with a new transcutaneous detector.

  1. Microstructural characterization of thin polymer films using Langley low energy positron flux generator

    NASA Technical Reports Server (NTRS)

    Singh, Jag. J.

    1992-01-01

    We have developed a highly efficient scheme for generating high fluxes of slow positrons. These positrons have been successfully used to measure lifetimes in thin test films. The lifetime data have been used to develop two structure-property models for the test films. The first model relates the free volume cell size to the molecular weight of the polymer repeat unit. The second model relates the free volume fraction to the dielectric constant of the polymer film.

  2. Characterization of bulk AlN crystals with positron annihilation spectroscopy

    Microsoft Academic Search

    F. Tuomisto; J.-M. Mäki; T. Yu. Chemekova; Yu. N. Makarov; O. V. Avdeev; E. N. Mokhov; A. S. Segal; M. G. Ramm; S. Davis; G. Huminic; H. Helava; M. Bickermann; B. M. Epelbaum

    2008-01-01

    We have applied positron annihilation spectroscopy to study in-grown vacancy defects in bulk aluminium nitride (AlN) crystals grown by physical vapor transport. We interpret the lowest lifetime value of about 155ps, measured at low temperatures, to represent the annihilations from the free state of the positron in the crystal lattice. The increased lifetime at high temperatures is an indication of

  3. Lifetime prediction for electronic components and circuits using the phase noise measuring method

    Microsoft Academic Search

    K. Hoffmann; R. Vogt

    1982-01-01

    A method of lifetime prediction for electronic components and circuits using the temporal evolution of the phase noise level (PNL) as quality criterion is presented. The PNL is shown to be a direct measure for the advance of deficiency processes. A measuring device to determine PNL, and a mathematical method to evaluate the measured data are described. Measurements between 180

  4. Positron trapping kinetics in thermally generated vacancy donor complexes in highly As-doped silicon

    Microsoft Academic Search

    K. Kuitunen; K. Saarinen; F. Tuomisto

    2007-01-01

    We have measured positron lifetime and Doppler broadening in highly As-doped silicon containing thermally generated V-As3 defect complexes (vacancy is surrounded by three arsenic atoms). We observe positron detrapping from the V-As3 defect complex and determine the binding energy of 0.27eV of a positron to the complex. The results explain why 85% of the thermal vacancies formed in highly As-doped

  5. A portable time-domain LED fluorimeter for nanosecond fluorescence lifetime measurements

    SciTech Connect

    Wang, Hongtao; Salthouse, Christopher D., E-mail: salthouse@ecs.umass.edu [Electrical and Computer Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Center for Personalized Health Monitoring, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Qi, Ying; Mountziaris, T. J. [Center for Personalized Health Monitoring, University of Massachusetts, Amherst, Massachusetts 01003 (United States) [Center for Personalized Health Monitoring, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Chemical Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003 (United States)

    2014-05-15

    Fluorescence lifetime measurements are becoming increasingly important in chemical and biological research. Time-domain lifetime measurements offer fluorescence multiplexing and improved handling of interferers compared with the frequency-domain technique. In this paper, an all solid-state, filterless, and highly portable light-emitting-diode based time-domain fluorimeter (LED TDF) is reported for the measurement of nanosecond fluorescence lifetimes. LED based excitation provides more wavelengths options compared to laser diode based excitation, but the excitation is less effective due to the uncollimated beam, less optical power, and longer latency in state transition. Pulse triggering and pre-bias techniques were implemented in our LED TDF to improve the peak optical power to over 100 mW. The proposed pulsing circuit achieved an excitation light fall time of less than 2 ns. Electrical resetting technique realized a time-gated photo-detector to remove the interference of the excitation light with fluorescence. These techniques allow the LED fluorimeter to accurately measure the fluorescence lifetime of fluorescein down to concentration of 0.5 ?M. In addition, all filters required in traditional instruments are eliminated for the non-attenuated excitation/emission light power. These achievements make the reported device attractive to biochemical laboratories seeking for highly portable lifetime detection devices for developing sensors based on fluorescence lifetime changes. The device was initially validated by measuring the lifetimes of three commercial fluorophores and comparing them with reported lifetime data. It was subsequently used to characterize a ZnSe quantum dot based DNA sensor.

  6. Temperature dependence of positron-annihilation lifetime, free volume, conductivity, ionic mobility, and number of charge carriers in a polymer electrolyte polyethylene oxide complexed with NH{sub 4}ClO{sub 4}

    SciTech Connect

    Haldar, B.; Singru, R.M. [Department of Physics, Indian Institute of Technology, Kanpur, 208016 (India)] [Department of Physics, Indian Institute of Technology, Kanpur, 208016 (India); Maurya, K.K.; Chandra, S. [Department of Physics, Banaras Hindu University, Varanasi, 221005 (India)] [Department of Physics, Banaras Hindu University, Varanasi, 221005 (India)

    1996-09-01

    Various physical properties of the solution-cast films of the proton conducting polymer polyethylene oxide (PEO) complexed with ammonium perchlorate (NH{sub 4}ClO{sub 4}) have been studied in the temperature range 300{endash}370 K. These properties studied by us include free volume by positron lifetime spectroscopy, ionic conductivity by impedance spectroscopy, ionic mobility by transient ionic current technique, number of charge carriers, dielectric constant, etc. The hole volume and conductivity show a steep rise at {ital T}{approx_equal}{ital T}{sub {ital m}} ({approximately}333 K). It appears that the increase in free volume arises out of the increase in the size of the holes rather than an increase in their number. Although the free volume shows an increase around {ital T}{sub {ital m}}, the measured ionic mobility does not show similar behavior. The increase in the conductivity at {ital T}{sub {ital m}} is, therefore, ascribed to an increase in the number of charge carriers at {approximately}{ital T}{sub {ital m}}. A suitable dissociation model involving the dielectric constant is proposed to explain this increase. The value of the dissociation energy for PEO:NH{sub 4}ClO{sub 4} has been determined to be 2.4 eV. {copyright} {ital 1996 The American Physical Society.}

  7. Towards an In-Beam Measurement of the Neutron Lifetime to 1 Second

    NASA Astrophysics Data System (ADS)

    Mulholland, Jonathan

    2014-03-01

    A precise value for the neutron lifetime is required for consistency tests of the Standard Model and is an essential parameter in the theory of Big Bang Nucleosynthesis. A new measurement of the neutron lifetime using the in-beam method is planned at the National Institute of Standards and Technology Center for Neutron Research. The systematic effects associated with the in-beam method are markedly different than those found in storage experiments utilizing ultracold neutrons. Experimental improvements, specifically recent advances in the determination of absolute neutron fluence, should permit an overall uncertainty of 1 second on the neutron lifetime. The dependence of the primordial mass fraction on the neutron lifetime, technical improvements of the in-beam technique, and the path toward improving the precision of the new measurement will be discussed.

  8. First working group meeting on the minority carrier diffusion length/lifetime measurement: Results of the round robin lifetime/diffusion length tests

    SciTech Connect

    Cudzinovic, M.; Sopori, B. [comp.] [comp.

    1995-11-01

    As was noted in the cover letter that accompanied the samples, the eleven bare silicon samples were from various manufacturers. Table I lists the codes for the samples and the manufacturer of each sample. It also notes if the sample was single or poly-crystalline. The samples had been polished on one side before being sent out for measurements, but no further processing was done. The participants of the study were asked to measure either the lifetime or diffusion length of each of the samples using their standard procedure. Table II shows the experimental conditions used by the groups who measured diffusion length. All the diffusion length measurements were performed using the Surface Photovoltage method (SPV). Table M shows the experimental conditions for the lifetime measurements. All the lifetime measurements were made using the Photoconductance Decay method (PCD) under low level injection. These tables show the diameter of the spot size used during the measurement (the effective sampling area), the locations where measurements were taken, and the number of measurements taken at each location. Table N shows the results of the measurements. The table is divided into diffusion length and lifetime measurements for each sample. The values listed are the average values reported by each group. One of the immediate artifacts seen in the data is the large variation in the lifetime measurements. The values from MIT and Mobil are generally close. However, the measurements from NCSU are typically an order of magnitude lower.

  9. Cascade Problems in Some Atomic Lifetime Measurements at a Heavy-Ion Storage Ring

    SciTech Connect

    Trabert, E; Hoffmann, J; Krantz, C; Wolf, A; Ishikawa, Y; Santana, J

    2008-10-09

    Lifetimes of 3s{sup 2}3p{sup k} ground configuration levels of Al-, Si-, P-, and S-like ions of Be, Co, and Ni have been measured at a heavy-ion storage ring. Some of the observed decay curves show strong evidence of cascade repopulation from specific 3d levels that feature lifetimes in the same multi-millisecond range as the levels of the ground configuration.

  10. Precision Lifetime Measurement of 2{sub 1}{sup +} State in {sup 120}Te

    SciTech Connect

    Terry, J. R.; Werner, V.; Casperson, R. J.; Casten, R. F.; Heinz, A.; McCutchan, E. A.; Qian, J.; Williams, E.; Winkler, R. [Wright Nuclear Structure Lab, Yale University, New Haven CT 06520-8124 (United States); Berant, Z. [Wright Nuclear Structure Lab, Yale University, New Haven CT 06520-8124 (United States); Nuclear Research Center Negev, Beer-Sheva, 84190 Israel (Israel); Henning, G. [Wright Nuclear Structure Lab, Yale University, New Haven CT 06520-8124 (United States); Department of Physics, ENS de Cachan, 94230 Cachan (France); Luettke, R. [Wright Nuclear Structure Lab, Yale University, New Haven CT 06520-8124 (United States); Technische Universitaet Darmstadt, 63289 Darmstadt (Germany); Shoraka, B. [Wright Nuclear Structure Lab, Yale University, New Haven CT 06520-8124 (United States); Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2009-01-28

    The lifetime of the {sup 120}Te first-excited 2{sup +} state is measured using the recoil distance Doppler shift (RDDS) method after population by inverse-kinematics Coulomb excitation. The resulting mean lifetime of 10.4(2) ps provides a factor of ten improvement in precision relative to the previously accepted value. A number of necessary corrections are discussed stemming from relativistic effects due to large recoil velocities.

  11. Precision measurement of the metastable 6s [3\\/2]2 lifetime in xenon

    Microsoft Academic Search

    M. Walhout; A. Witte; S. L. Rolston

    1994-01-01

    Using a magneto-optical trap to isolate an isotopically pure sample of xenon, we determine the metastable 6s [3\\/2]2 state lifetime by measuring the rate of VUV emisson due to magnetic quadrupole decay. We find lifetimes of 42.9(9) s and 42.4(13) s for 132Xe and 136Xe, respectively (1sigma uncertainties). These values are less than half the theoretical predictions. We also find

  12. ATOMIC AND MOLECULAR PHYSICS: Lifetime Measurement of Cold Atoms in an Integrating Sphere

    NASA Astrophysics Data System (ADS)

    Zhang, Wen-Zhuo; Wang, Xu-Cheng; Cheng, Hua-Dong; Xiao, Ling; Liu, Liang; Wang, Yu-Zhu

    2009-08-01

    We present an experimental measurement of the lifetime of the cold 87Rb atoms in an integrating sphere. The atoms are cooled by the diffuse light which is generated by the diffuse reflection of laser beams in the integrating sphere. Our result shows that the lifetime is primarily determined by the free fall of the cold 87Rb atoms, and its half-life can reach 40 ms, which is suitable for many experiments, especially for a cold atom clock.

  13. Precision measurements of the charged Lambda c and neutral D meson lifetimes

    NASA Astrophysics Data System (ADS)

    Kushnirenko, Alexander Yevgenievich

    2001-07-01

    We report new precision measurements of the lifetimes of the L+c and D0 from SELEX, the charm hadro-production experiment at Fermilab. Based upon 1630 L+c and 10210 D0 decays we observe lifetimes of ?[ L+c ] = 198.1 +/- 7.0 +/- 5.7 fs and ?[D 0] = 407.9 +/- 6.0 +/- 4.7 fs.

  14. Measuring and modeling the lifetime of nitrous oxide including its variability

    NASA Astrophysics Data System (ADS)

    Prather, Michael J.; Hsu, Juno; DeLuca, Nicole M.; Jackman, Charles H.; Oman, Luke D.; Douglass, Anne R.; Fleming, Eric L.; Strahan, Susan E.; Steenrod, Stephen D.; Søvde, O. Amund; Isaksen, Ivar S. A.; Froidevaux, Lucien; Funke, Bernd

    2015-06-01

    The lifetime of nitrous oxide, the third-most-important human-emitted greenhouse gas, is based to date primarily on model studies or scaling to other gases. This work calculates a semiempirical lifetime based on Microwave Limb Sounder satellite measurements of stratospheric profiles of nitrous oxide, ozone, and temperature; laboratory cross-section data for ozone and molecular oxygen plus kinetics for O(1D); the observed solar spectrum; and a simple radiative transfer model. The result is 116 ± 9 years. The observed monthly-to-biennial variations in lifetime and tropical abundance are well matched by four independent chemistry-transport models driven by reanalysis meteorological fields for the period of observation (2005-2010), but all these models overestimate the lifetime due to lower abundances in the critical loss region near 32 km in the tropics. These models plus a chemistry-climate model agree on the nitrous oxide feedback factor on its own lifetime of 0.94 ± 0.01, giving N2O perturbations an effective residence time of 109 years. Combining this new empirical lifetime with model estimates of residence time and preindustrial lifetime (123 years) adjusts our best estimates of the human-natural balance of emissions today and improves the accuracy of projected nitrous oxide increases over this century.

  15. Measuring the neutron lifetime using magnetically trapped neutrons

    NASA Astrophysics Data System (ADS)

    O'Shaughnessy, C. M.; Golub, R.; Schelhammer, K. W.; Swank, C. M.; Seo, P.-N.; Huffman, P. R.; Dzhosyuk, S. N.; Mattoni, C. E. H.; Yang, L.; Doyle, J. M.; Coakley, K. J.; Thompson, A. K.; Mumm, H. P.; Lamoreaux, S. K.; McKinsey, D. N.; Yang, G.

    2009-12-01

    The neutron beta-decay lifetime plays an important role both in understanding weak interactions within the framework of the Standard Model and in theoretical predictions of the primordial abundance of 4He in Big Bang Nucleosynthesis. In previous work, we successfully demonstrated the trapping of ultracold neutrons in a conservative potential magnetic trap. A major upgrade of the apparatus is nearing completion at the National Institute of Standards and Technology Center for Neutron Research (NCNR). In our approach, a beam of 0.89 nm neutrons is incident on a superfluid 4He target within the minimum field region of an Ioffe-type magnetic trap. A fraction of the neutrons is downscattered in the helium to energies <200 neV, and those in the appropriate spin state become trapped. The inverse process is suppressed by the low phonon density of helium at temperatures less than 200 mK, allowing the neutron to travel undisturbed. When the neutron decays the energetic electron ionizes the helium, producing scintillation light that is detected using photomultiplier tubes. Statistical limitations of the previous apparatus will be alleviated by significant increases in field strength and trap volume resulting in twenty times more trapped neutrons.

  16. Polymeric membrane studied using slow positron beam

    NASA Astrophysics Data System (ADS)

    Hung, Wei-Song; Lo, Chia-Hao; Cheng, Mei-Ling; Chen, Hongmin; Liu, Guang; Chakka, Lakshmi; Nanda, D.; Tung, Kuo-Lun; Huang, Shu-Hsien; Lee, Kueir-Rarn; Lai, Juin-Yih; Sun, Yi-Ming; Yu, Chang-Cheng; Zhang, Renwu; Jean, Y. C.

    2008-10-01

    A radioisotope slow positron beam has been built at the Chung Yuan Christian University in Taiwan for the research and development in membrane science and technology. Doppler broadening energy spectra and positron annihilation lifetime have been measured as a function of positron energy up to 30 keV in a polyamide membrane prepared by the interfacial polymerization between triethylenetetraamine (TETA) and trimesoyl chloride (TMC) on modified porous polyacrylonitrile (PAN) asymmetric membrane. The multilayer structures and free-volume depth profile for this asymmetric membrane system are obtained. Positron annihilation spectroscopy coupled with a slow beam could provide new information about size selectivity of transporting molecules and guidance for molecular designs in polymeric membranes.

  17. About Possibility for Examination of Gravity Theories Using the Precise Measurement of Particle Lifetime

    E-print Network

    Kh. M. Beshtoev

    2003-08-12

    An approach for examination of gravitational theories using precision measurements of particle lifetime is proposed. The expressions describing dependence of particle lifetime on gravitational potential in Einstein's and Newton's gravity theories are obtained. In the case of Newton's gravity there is a dependence of the particle velocity direction from the direction of matter location, which creates the gravitational potential. If the external gravitational field is spherical symmetric then there would be no possibility to distinguish these types of gravity. It is found that the deposit of gravitational potential of the Universe (in the case of uniformly distribution of matter in the Universe) in particle lifetime is approximately one percent. On the basis of the available experimental data it is found that deposit of asymmetric gravitational field is $\\frac{\\phi}{c^2} \\simeq 2 \\cdot 10^{-4}$, i.e., if the experimental precision of particle lifetime measurements will be several units of $10^{-4}$, then we could see this effect. In reality, the lifetime of elementary particles can be defined by effective masses of these particles in the external gravitational field. The expressions for effective masses of particles in the external gravitational field for two gravity type theories are obtained. These masses can be used at computation of the decay probability (or lifetime) of particles by standard methods. It is shown that in this case it is also possible to distinguish these two types of gravity theories.

  18. A measurement of lifetime differences in the neutral /D-meson system

    NASA Astrophysics Data System (ADS)

    Link, J. M.; Paolone, V. S.; Reyes, M.; Yager, P. M.; Anjos, J. C.; Bediaga, I.; Göbel, C.; Magnin, J.; de Miranda, J. M.; Pepe, I. M.; dos Reis, A. C.; Simão, F. R. A.; Vale, M. A.; Carrillo, S.; Casimiro, E.; Mendez, H.; Sánchez-Hernández, A.; Uribe, C.; Vazquez, F.; Cinquini, L.; Cumalat, J. P.; Ramirez, J. E.; O'Reilly, B.; Vaandering, E. W.; Butler, J. N.; Cheung, H. W. K.; Gaines, I.; Garbincius, P. H.; Garren, L. A.; Gottschalk, E.; Gourlay, S. A.; Kasper, P. H.; Kreymer, A. E.; Kutschke, R.; Bianco, S.; Fabbri, F. L.; Sarwar, S.; Zallo, A.; Cawlfield, C.; Kim, D. Y.; Park, K. S.; Rahimi, A.; Wiss, J.; Gardner, R.; Chung, Y. S.; Kang, J. S.; Ko, B. R.; Kwak, J. W.; Lee, K. B.; Myung, S. S.; Park, H.; Alimonti, G.; Boschini, M.; Brambilla, D.; Caccianiga, B.; Calandrino, A.; D'Angelo, P.; DiCorato, M.; Dini, P.; Giammarchi, M.; Inzani, P.; Leveraro, F.; Malvezzi, S.; Menasce, D.; Mezzadri, M.; Milazzo, L.; Moroni, L.; Pedrini, D.; Prelz, F.; Rovere, M.; Sala, A.; Sala, S.; Davenport, T. F., III; Arena, V.; Boca, G.; Bonomi, G.; Gianini, G.; Liguori, G.; Merlo, M.; Pantea, D.; Ratti, S. P.; Riccardi, C.; Torre, P.; Viola, L.; Vitulo, P.; Hernandez, H.; Lopez, A. M.; Mendez, L.; Mirles, A.; Montiel, E.; Olaya, D.; Quinones, J.; Rivera, C.; Zhang, Y.; Copty, N.; Purohit, M.; Wilson, J. R.; Cho, K.; Handler, T.; Engh, D.; Johns, W. E.; Hosack, M.; Nehring, M. S.; Sales, M.; Sheldon, P. D.; Stenson, K.; Webster, M. S.; Sheaff, M.; Kwon, Y. J.

    2000-07-01

    Using a high statistics sample of photoproduced charm particles from the FOCUS experiment at Fermilab, we compare the lifetimes of neutral /D mesons decaying via D0-->K-?+andK- K+ to measure the lifetime differences between CP even and CP odd final states. These measurements bear on the phenomenology of D0-D¯0 mixing. If the D0-->K-?+ is an equal mixture of CP even and CP odd eigenstates, we measure yCP=(?(CPeven)- ?(CPodd))/(?(CPeven)+?(CPodd))=0.0342+/-0.0139+/- 0.0074.

  19. Recoil Distance Method lifetime measurements via gamma-ray and charged-particle spectroscopy at NSCL

    NASA Astrophysics Data System (ADS)

    Voss, Philip Jonathan

    The Recoil Distance Method (RDM) is a well-established technique for measuring lifetimes of electromagnetic transitions. Transition matrix elements derived from the lifetimes provide valuable insight into nuclear structure. Recent RDM investigations at NSCL present a powerful new model-independent tool for the spectroscopy of nuclei with extreme proton-to-neutron ratios that exhibit surprising behavior. Neutron-rich 18C is one such example, where a small B(E2; 2+1 ? 0+gs) represented a dramatic shift from the expected inverse relationship between the B(E2) and 2+1 excitation energy. To shed light on the nature of this quadrupole excitation, the RDM lifetime technique was applied with the Koln/NSCL plunger. States in 18C were populated by the one-proton knockout reaction of a 19N secondary beam. De-excitation gamma rays were detected with the Segmented Germanium Array in coincidence with reaction residues at the focal plane of the S800 Magnetic Spectrometer. The deduced B(E2) and excitation energy were both well described by ab initio no-core shell model calculations. In addition, a novel extension of RDM lifetime measurements via charged-particle spectroscopy of exotic proton emitters has been investigated. Substituting the reaction residue degrader of the Koln/NSCL plunger with a thin silicon detector permits the study of short-lived nuclei beyond the proton dripline. A proof of concept measurement of the mean lifetime of the two-proton emitter 19Mg was conducted. The results indicated a sub-picosecond lifetime, one order of magnitude smaller than the published results, and validate this new technique for lifetime measurements of charged-particle emitters.

  20. Electron and Positron Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

    NASA Astrophysics Data System (ADS)

    Aguilar, M.; Aisa, D.; Alvino, A.; Ambrosi, G.; Andeen, K.; Arruda, L.; Attig, N.; Azzarello, P.; Bachlechner, A.; Barao, F.; Barrau, A.; Barrin, L.; Bartoloni, A.; Basara, L.; Battarbee, M.; Battiston, R.; Bazo, J.; Becker, U.; Behlmann, M.; Beischer, B.; Berdugo, J.; Bertucci, B.; Bigongiari, G.; Bindi, V.; Bizzaglia, S.; Bizzarri, M.; Boella, G.; de Boer, W.; Bollweg, K.; Bonnivard, V.; Borgia, B.; Borsini, S.; Boschini, M. J.; Bourquin, M.; Burger, J.; Cadoux, F.; Cai, X. D.; Capell, M.; Caroff, S.; Casaus, J.; Cascioli, V.; Castellini, G.; Cernuda, I.; Cervelli, F.; Chae, M. J.; Chang, Y. H.; Chen, A. I.; Chen, H.; Cheng, G. M.; Chen, H. S.; Cheng, L.; Chikanian, A.; Chou, H. Y.; Choumilov, E.; Choutko, V.; Chung, C. H.; Clark, C.; Clavero, R.; Coignet, G.; Consolandi, C.; Contin, A.; Corti, C.; Coste, B.; Cui, Z.; Dai, M.; Delgado, C.; Della Torre, S.; Demirköz, M. B.; Derome, L.; Di Falco, S.; Di Masso, L.; Dimiccoli, F.; Díaz, C.; von Doetinchem, P.; Du, W. J.; Duranti, M.; D'Urso, D.; Eline, A.; Eppling, F. J.; Eronen, T.; Fan, Y. Y.; Farnesini, L.; Feng, J.; Fiandrini, E.; Fiasson, A.; Finch, E.; Fisher, P.; Galaktionov, Y.; Gallucci, G.; García, B.; García-López, R.; Gast, H.; Gebauer, I.; Gervasi, M.; Ghelfi, A.; Gillard, W.; Giovacchini, F.; Goglov, P.; Gong, J.; Goy, C.; Grabski, V.; Grandi, D.; Graziani, M.; Guandalini, C.; Guerri, I.; Guo, K. H.; Habiby, M.; Haino, S.; Han, K. C.; He, Z. H.; Heil, M.; Hoffman, J.; Hsieh, T. H.; Huang, Z. C.; Huh, C.; Incagli, M.; Ionica, M.; Jang, W. Y.; Jinchi, H.; Kanishev, K.; Kim, G. N.; Kim, K. S.; Kirn, Th.; Kossakowski, R.; Kounina, O.; Kounine, A.; Koutsenko, V.; Krafczyk, M. S.; Kunz, S.; La Vacca, G.; Laudi, E.; Laurenti, G.; Lazzizzera, I.; Lebedev, A.; Lee, H. T.; Lee, S. C.; Leluc, C.; Li, H. L.; Li, J. Q.; Li, Q.; Li, Q.; Li, T. X.; Li, W.; Li, Y.; Li, Z. H.; Li, Z. Y.; Lim, S.; Lin, C. H.; Lipari, P.; Lippert, T.; Liu, D.; Liu, H.; Lomtadze, T.; Lu, M. J.; Lu, Y. S.; Luebelsmeyer, K.; Luo, F.; Luo, J. Z.; Lv, S. S.; Majka, R.; Malinin, A.; Mañá, C.; Marín, J.; Martin, T.; Martínez, G.; Masi, N.; Maurin, D.; Menchaca-Rocha, A.; Meng, Q.; Mo, D. C.; Morescalchi, L.; Mott, P.; Müller, M.; Ni, J. Q.; Nikonov, N.; Nozzoli, F.; Nunes, P.; Obermeier, A.; Oliva, A.; Orcinha, M.; Palmonari, F.; Palomares, C.; Paniccia, M.; Papi, A.; Pedreschi, E.; Pensotti, S.; Pereira, R.; Pilo, F.; Piluso, A.; Pizzolotto, C.; Plyaskin, V.; Pohl, M.; Poireau, V.; Postaci, E.; Putze, A.; Quadrani, L.; Qi, X. M.; Rancoita, P. G.; Rapin, D.; Ricol, J. S.; Rodríguez, I.; Rosier-Lees, S.; Rozhkov, A.; Rozza, D.; Sagdeev, R.; Sandweiss, J.; Saouter, P.; Sbarra, C.; Schael, S.; Schmidt, S. M.; Schuckardt, D.; von Dratzig, A. Schulz; Schwering, G.; Scolieri, G.; Seo, E. S.; Shan, B. S.; Shan, Y. H.; Shi, J. Y.; Shi, X. Y.; Shi, Y. M.; Siedenburg, T.; Son, D.; Spada, F.; Spinella, F.; Sun, W.; Sun, W. H.; Tacconi, M.; Tang, C. P.; Tang, X. W.; Tang, Z. C.; Tao, L.; Tescaro, D.; Ting, Samuel C. C.; Ting, S. M.; Tomassetti, N.; Torsti, J.; Türko?lu, C.; Urban, T.; Vagelli, V.; Valente, E.; Vannini, C.; Valtonen, E.; Vaurynovich, S.; Vecchi, M.; Velasco, M.; Vialle, J. P.; Wang, L. Q.; Wang, Q. L.; Wang, R. S.; Wang, X.; Wang, Z. X.; Weng, Z. L.; Whitman, K.; Wienkenhöver, J.; Wu, H.; Xia, X.; Xie, M.; Xie, S.; Xiong, R. Q.; Xin, G. M.; Xu, N. S.; Xu, W.; Yan, Q.; Yang, J.; Yang, M.; Ye, Q. H.; Yi, H.; Yu, Y. J.; Yu, Z. Q.; Zeissler, S.; Zhang, J. H.; Zhang, M. T.; Zhang, X. B.; Zhang, Z.; Zheng, Z. M.; Zhuang, H. L.; Zhukov, V.; Zichichi, A.; Zimmermann, N.; Zuccon, P.; Zurbach, C.; AMS Collaboration

    2014-09-01

    Precision measurements by the Alpha Magnetic Spectrometer on the International Space Station of the primary cosmic-ray electron flux in the range 0.5 to 700 GeV and the positron flux in the range 0.5 to 500 GeV are presented. The electron flux and the positron flux each require a description beyond a single power-law spectrum. Both the electron flux and the positron flux change their behavior at ˜30 GeV but the fluxes are significantly different in their magnitude and energy dependence. Between 20 and 200 GeV the positron spectral index is significantly harder than the electron spectral index. The determination of the differing behavior of the spectral indices versus energy is a new observation and provides important information on the origins of cosmic-ray electrons and positrons.

  1. Measurements of positron-methane differential scattering cross sections

    SciTech Connect

    Przybyla, D.A.; Kauppila, W.E.; Kwan, C.K.; Smith, S.J.; Stein, T.S. [Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48202 (United States)] [Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48202 (United States)

    1997-06-01

    Relative differential cross sections (DCS{close_quote}s) have been measured for 4 to 200 eV e{sup +}-CH{sub 4} quasielastic scattering (elastic scattering plus rotational and vibrational excitations) from 30{degree} to 135{degree} in a crossed-beam experiment. The observed DCS behavior, including diffraction effects at low energies, is very similar to that found earlier for e{sup +}-Ar elastic scattering. Comparisons between (e{sup +},e{sup {minus}})-(CH{sub 4},Ar) DCS measurements suggest that observed diffraction effects may be correlated with the sign of the net interaction potential and the degree of spherical symmetry of the target. {copyright} {ital 1997} {ital The American Physical Society}

  2. Positron trapping kinetics in thermally generated vacancy donor complexes in highly As-doped silicon

    NASA Astrophysics Data System (ADS)

    Kuitunen, K.; Saarinen, K.; Tuomisto, F.

    2007-01-01

    We have measured positron lifetime and Doppler broadening in highly As-doped silicon containing thermally generated V-As3 defect complexes (vacancy is surrounded by three arsenic atoms). We observe positron detrapping from the V-As3 defect complex and determine the binding energy of 0.27eV of a positron to the complex. The results explain why 85% of the thermal vacancies formed in highly As-doped Si at temperatures over 700K are invisible to positron measurements at elevated temperatures.

  3. Fabrication of 94Zr thin target for recoil distance doppler shift method of lifetime measurement

    NASA Astrophysics Data System (ADS)

    Gupta, C. K.; Rohilla, Aman; Abhilash, S. R.; Kabiraj, D.; Singh, R. P.; Mehta, D.; Chamoli, S. K.

    2014-11-01

    A thin isotopic 94Zr target of thickness 520 ?g/cm2 has been prepared for recoil distance Doppler shift method (RDM) lifetime measurement by using an electron beam deposition method on tantalum backing of 3.5 mg/cm2 thickness at Inter University Accelerator Center (IUAC), New Delhi. To meet the special requirement of smoothness of surface for RDM lifetime measurement and also to protect the outer layer of 94Zr from peeling off, a very thin layer of gold has been evaporated on a 94Zr target on a specially designed substrate holder. In all, 143 mg of 99.6% enriched 94Zr target material was utilized for the fabrication of 94Zr targets. The target has been successfully used in a recent RDM lifetime measurement experiment at IUAC.

  4. Status of neutron lifetime measuring in magneto-gravitational

    E-print Network

    Titov, Anatoly

    ( )k x X z B=0 Depend on period of magnetic structure #12;Our waited accuracy about 0.2-0.3 s of main advantage i.e. "How we can measure our losses?" ­ Fomblin ­ Efficiency measuring · Filling of trap · Correction of the trap design #12;· V.F.Ezhov,1 A.Z.Andreev,1 G.Ban2 B.A.Bazarov,1 P.Geltenbort,3 F

  5. Lifetime measurements of Triaxial Strongly Deformed bands in $^{163}$Tm

    E-print Network

    X. wang; R. V. F. Janssens; E. F. Moore; U. Garg; Y. Gu; S. Frauendorf; M. P. Carpenter; S. S. Ghugre; N. J. Hammond; T. Lauritsen; T. Li; G. Mukherjee; N. S. Pattabiraman; D. Seweryniak; S. Zhu

    2007-05-14

    With the Doppler Shift Attenuation Method, quadrupole transition moments, $Q_t$, were determined for the two recently proposed Triaxial Strongly Deformed (TSD) bands in $^{163}$Tm. The measured $Q_t$ moments indicate that the deformation of these bands is larger than that of the yrast, signature partners. However, the measured values are smaller than those predicted by theory. This observation appears to be valid for TSD bands in several nuclei of the region

  6. Variations in the electrical short-circuit current decay for recombination lifetime and velocity measurements

    NASA Technical Reports Server (NTRS)

    Jung, Tae-Won; Lindholm, Fredrik A.; Neugroschel, Arnost

    1987-01-01

    An improved measurement system for electrical short-circuit current decay is presented that extends applicability of the method to silicon solar cells having an effective lifetime as low as 1 microsec. The system uses metal/oxide/semiconductor transistors as voltage-controlled switches. Advances in theory developed here increase precision and sensitivity in the determination of the minority-carrier recombination lifetime and recombination velocity. A variation of the method, which exploits measurements made on related back-surface field and back-ohmic contact devices, further improves precision and sensitivity. The improvements are illustrated by application to 15 different silicon solar cells.

  7. Lifetime Measurement of the First Excited 2{sup +} State in {sup 16}C

    SciTech Connect

    Wiedeking, M.; Fallon, P.; Macchiavelli, A. O.; Gibelin, J.; Basunia, M. S.; Clark, R. M.; Cromaz, M.; Deleplanque, M.-A.; Gros, S.; Jeppesen, H. B.; Lake, P. T.; Lee, I.-Y.; Moretto, L. G.; Pavan, J.; Phair, L.; Rodriguez-Vietiez, E.; Bernstein, L. A.; Bleuel, D. L.; Burke, J. T.; Lesher, S. R. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)] (and others)

    2008-04-18

    The lifetime of the 2{sub 1}{sup +} state in {sup 16}C has been measured with the recoil distance method using the {sup 9}Be({sup 9}Be,2p) fusion-evaporation reaction at a beam energy of 40 MeV. The mean lifetime was measured to be 11.7(20) ps corresponding to a B(E2; 2{sub 1}{sup +}{yields}0{sup +}) value of 4.15(73)e{sup 2} fm{sup 4} [1.73(30) W.u.], consistent with other even-even closed shell nuclei. Our result does not support an interpretation for ''decoupled'' valence neutrons.

  8. Measurement of the Ratio of B+ and B0 Meson Lifetimes

    Microsoft Academic Search

    V. M. Abazov; B. Abbott; M. Abolins; B. S. Acharya; M. Adams; T. Adams; M. Agelou; J.-L. Agram; S. H. Ahn; M. Ahsan; G. D. Alexeev; G. Alkhazov; A. Alton; G. Alverson; G. A. Alves; M. Anastasoaie; S. Anderson; B. Andrieu; Y. Arnoud; A. Askew; B. Åsman; O. Atramentov; C. Autermann; C. Avila; F. Badaud; A. Baden; B. Baldin; P. W. Balm; S. Banerjee; E. Barberis; P. Bargassa; P. Baringer; C. Barnes; J. F. Bartlett; U. Bassler; D. Bauer; A. Bellavance; S. Beauceron; M. Begel; S. B. Beri; G. Bernardi; R. Bernhard; I. Bertram; M. Besançon; R. Beuselinck; V. A. Bezzubov; P. C. Bhat; V. Bhatnagar; M. Binder; K. M. Black; I. Blackler; G. Blazey; F. Blekman; S. Blessing; D. Bloch; U. Blumenschein; A. Boehnlein; O. Boeriu; T. A. Bolton; F. Borcherding; G. Borissov; K. Bos; T. Bose; A. Brandt; R. Brock; G. Brooijmans; A. Bross; N. J. Buchanan; D. Buchholz; M. Buehler; V. Buescher; S. Burdin; T. H. Burnett; E. Busato; J. M. Butler; J. Bystricky; W. Carvalho; B. C. Casey; N. M. Cason; H. Castilla-Valdez; S. Chakrabarti; D. Chakraborty; K. M. Chan; A. Chandra; D. Chapin; F. Charles; E. Cheu; L. Chevalier; D. K. Cho; S. Choi; T. Christiansen; L. Christofek; D. Coppage; B. Clément; C. Clément; Y. Coadou; M. Cooke; W. E. Cooper; M. Corcoran; J. Coss; A. Cothenet; M.-C. Cousinou; S. Crépé-Renaudin; M. Cristetiu; M. A. Cummings; D. Cutts; H. da Motta; B. Davies; G. Davies; G. A. Davis; K. de; P. de Jong; S. J. de Jong; E. de La Cruz-Burelo; C. de Oliveira Martins; S. Dean; F. Déliot; P. A. Delsart; M. Demarteau; R. Demina; P. Demine; D. Denisov; S. P. Denisov; S. Desai; H. T. Diehl; M. Diesburg; M. Doidge; H. Dong; S. Doulas; L. Duflot; S. R. Dugad; A. Duperrin; J. Dyer; A. Dyshkant; M. Eads; D. Edmunds; T. Edwards; J. Ellison; J. Elmsheuser; J. T. Eltzroth; V. D. Elvira; S. Eno; P. Ermolov; O. V. Eroshin; J. Estrada; D. Evans; H. Evans; A. Evdokimov; V. N. Evdokimov; J. Fast; S. N. Fatakia; L. Feligioni; T. Ferbel; F. Fiedler; F. Filthaut; W. Fisher; H. E. Fisk; M. Fortner; H. Fox; W. Freeman; S. Fu; S. Fuess; T. Gadfort; C. F. Galea; E. Gallas; E. Galyaev; C. Garcia; A. Garcia-Bellido; J. Gardner; V. Gavrilov; P. Gay; D. Gelé; R. Gelhaus; K. Genser; C. E. Gerber; Y. Gershtein; G. Ginther; T. Golling; B. Gómez; K. Gounder; A. Goussiou; P. D. Grannis; S. Greder; H. Greenlee; Z. D. Greenwood; E. M. Gregores; Ph. Gris; J.-F. Grivaz; L. Groer; S. Grünendahl; M. W. Grünewald; S. N. Gurzhiev; G. Gutierrez; P. Gutierrez; A. Haas; N. J. Hadley; S. Hagopian; I. Hall; R. E. Hall; C. Han; L. Han; K. Hanagaki; K. Harder; R. Harrington; J. M. Hauptman; R. Hauser; J. Hays; T. Hebbeker; D. Hedin; J. M. Heinmiller; A. P. Heinson; U. Heintz; C. Hensel; G. Hesketh; M. D. Hildreth; R. Hirosky; J. D. Hobbs; B. Hoeneisen; M. Hohlfeld; S. J. Hong; R. Hooper; P. Houben; Y. Hu; J. Huang; I. Iashvili; R. Illingworth; A. S. Ito; S. Jabeen; M. Jaffré; S. Jain; V. Jain; K. Jakobs; A. Jenkins; R. Jesik; K. Johns; M. Johnson; A. Jonckheere; P. Jonsson; H. Jöstlein; A. Juste; M. M. Kado; D. Käfer; W. Kahl; S. Kahn; E. Kajfasz; A. M. Kalinin; J. Kalk; D. Karmanov; J. Kasper; D. Kau; R. Kehoe; S. Kermiche; S. Kesisoglou; A. Khanov; A. Kharchilava; Y. M. Kharzheev; K. H. Kim; B. Klima; M. Klute; J. M. Kohli; M. Kopal; V. M. Korablev; J. Kotcher; B. Kothari; A. Koubarovsky; A. V. Kozelov; J. Kozminski; S. Krzywdzinski; S. Kuleshov; Y. Kulik; S. Kunori; A. Kupco; T. Kurca; S. Lager; N. Lahrichi; G. Landsberg; J. Lazoflores; A.-C. Le Bihan; P. Lebrun; S. W. Lee; W. M. Lee; A. Leflat; F. Lehner; C. Leonidopoulos; P. Lewis; J. Li; Q. Z. Li; J. G. Lima; D. Lincoln; S. L. Linn; J. Linnemann; V. V. Lipaev; R. Lipton; L. Lobo; A. Lobodenko; M. Lokajicek; A. Lounis; H. J. Lubatti; L. Lueking; M. Lynker; A. L. Lyon; A. K. Maciel; R. J. Madaras; P. Mättig; A. Magerkurth; A.-M. Magnan; N. Makovec; P. K. Mal; S. Malik; V. L. Malyshev; H. S. Mao; Y. Maravin; M. Martens; S. E. Mattingly; A. A. Mayorov; R. McCarthy; R. McCroskey; D. Meder; H. L. Melanson; A. Melnitchouk; M. Merkin; K. W. Merritt; A. Meyer; H. Miettinen; D. Mihalcea; J. Mitrevski; N. Mokhov; J. Molina; N. K. Mondal; H. E. Montgomery; R. W. Moore; G. S. Muanza; M. Mulders; Y. D. Mutaf; E. Nagy; M. Narain; N. A. Naumann; H. A. Neal; J. P. Negret; S. Nelson; P. Neustroev; C. Noeding; A. Nomerotski; S. F. Novaes; T. Nunnemann; E. Nurse; V. O'dell; D. C. O'Neil; V. Oguri; N. Oliveira; N. Oshima; G. J. Otero Y Garzón; P. Padley; N. Parashar; S. K. Park; J. Parsons; R. Partridge; N. Parua; A. Patwa; P. M. Perea; E. Perez; O. Peters; P. Pétroff; M. Petteni; L. Phaf; R. Piegaia; P. L. Podesta-Lerma; V. M. Podstavkov; Y. Pogorelov; B. G. Pope; W. L. Prado da Silva; H. B. Prosper; S. Protopopescu; M. B. Przybycien; J. Qian; A. Quadt; B. Quinn; K. J. Rani; P. A. Rapidis; P. N. Ratoff; N. W. Reay; S. Reucroft; M. Rijssenbeek; I. Ripp-Baudot; F. Rizatdinova; C. Royon; P. Rubinov

    2005-01-01

    The ratio of the B+ and B0 meson lifetimes was measured using data collected in 2002 2004 by the D0 experiment in Run II of the Fermilab Tevatron Collider. These mesons were reconstructed in B-->mu+nuD*-X decays, which are dominated by B0 and B-->mu+nuD¯0X decays, which are dominated by B+. The ratio of lifetimes is measured to be tau+\\/tau0=1.080±0.016(stat)±0.014(syst).

  9. Electron-positron momentum distribution measurements of high-T superconductors and related systems

    SciTech Connect

    Wachs, A.L.; Turchi, P.E.A.; Howell, R.J.; Jean, Y.C.; Fluss, M.J.; West, R.N.; Kaiser, J.H.; Rayner, S.; Hahgighi, H.; Merkle, K.L.; Revcolevschi, A.; Wang, Z.Z.

    1989-08-01

    We discuss our measurements of the 2D-angular correlation of positron annihilation radiation (ACAR) in La{sub 2}CuO{sub 4}, YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO), and NiO. The measurements for NiO are the first such 2D-ACAR measurements; the YBCO results are of a higher statistical quality than previously reported in the literature. The data are compared with complementary theoretical calculations and with each other. We discuss the implication of our analysis for ACAR studies of similar and related systems. 5 refs., 1 fig.

  10. Elecron-positron momentum distribution measurements of high-t/sub c/ superconductors and related systems

    SciTech Connect

    Wachs, A.L.; Turchi, P.E.A.; Howell, R.H.; Jean, Y.C.; Fluss, M.J.; West, R.N.; Kaiser, J.H.; Rayner, S.; Hahgighi, H.; Merkle, K.L.; Revcolevschi, A.

    1989-06-01

    We discuss our measurements of the 2D-angular correlation of positron annihilation radiation (ACAR) in La/sub 2/CuO/sub 4/, YBa/sub 2/Cu/sub 3/O/sub 7/ (YBCO), and NiO. The measurements for NiO are the first such 2D-ACAR measurements; the YBCO results are of a higher statistical quality than previously reported in the literature. The data are compared with complementary theoretical calculations and with each other. We discuss the implication of our analysis for ACAR studies of similar and related systems. 5 refs., 1 fig.

  11. Indirect Dark Matter Search: Cosmic Positron Fraction Measurement from 1 to 50 GeV with AMS-01

    E-print Network

    Gast, H; Schael, S; Gast, Henning; Olzem, Jan; Schael, Stefan

    2006-01-01

    A new measurement of the cosmic ray positron fraction in the energy range of 1-50 GeV is presented. The measurement is based on data taken by the AMS-01 experiment during its 10 day space shuttle flight in June 1998. A proton background suppression in the order of 10^6 is reached by identifying converted bremsstrahlung photons emitted from electrons and positrons.

  12. Indirect Dark Matter Search: Cosmic Positron Fraction Measurement from 1 to 50 GeV with AMS-01

    E-print Network

    Henning Gast; Jan Olzem; Stefan Schael

    2006-05-10

    A new measurement of the cosmic ray positron fraction in the energy range of 1-50 GeV is presented. The measurement is based on data taken by the AMS-01 experiment during its 10 day space shuttle flight in June 1998. A proton background suppression in the order of 10^6 is reached by identifying converted bremsstrahlung photons emitted from electrons and positrons.

  13. Measurement of the hadronic cross section in electron-positron annihilation

    SciTech Connect

    Clearwater, S.

    1983-11-01

    This thesis describes the most precise measurement to date of the ratio R, the hadronic cross section in lowest order electron-positron annihilation to the cross section for muon pair production in lowest order electron-positron annihilation. This experiment is of interest because R is a fundamental parameter that tests in a model independent way the basic assumptions of strong interaction theories. According to the assumptions of one of these theories the value of R is determined simply from the electric charges, spin, and color assignments of the produced quark-pairs. The experiment was carried out with the MAgnetic Calorimeter using collisions of 14.5 GeV electrons and positrons at the 2200m circumference PEP storage ring at SLAC. The MAC detector is one of the best-suited collider detectors for measuring R due to its nearly complete coverage of the full angular range. The data for this experiment were accumulated between February 1982 and April 1983 corresponding to a total event sample of about 40,000 hadronic events. About 5% of the data were taken with 14 GeV beams and the rest of the data were taken with 14.5 GeV beams. A description of particle interactions and experimental considerations is given.

  14. Measuring The Neutron Lifetime to One Second Using in Beam Techniques

    NASA Astrophysics Data System (ADS)

    Mulholland, Jonathan; NIST In Beam Lifetime Collaboration

    2013-10-01

    The decay of the free neutron is the simplest nuclear beta decay and is the prototype for charged current semi-leptonic weak interactions. A precise value for the neutron lifetime is required for consistency tests of the Standard Model and is an essential parameter in the theory of Big Bang Nucleosynthesis. A new measurement of the neutron lifetime using the in-beam method is planned at the National Institute of Standards and Technology Center for Neutron Research. The systematic effects associated with the in-beam method are markedly different than those found in storage experiments utilizing ultracold neutrons. Experimental improvements, specifically recent advances in the determination of absolute neutron fluence, should permit an overall uncertainty of 1 second on the neutron lifetime. The technical improvements in the in-beam technique, and the path toward improving the precision of the new measurement will be discussed.

  15. Phase Space Evolution in Neutron Traps for Measurements of the Neutron Beta-Decay Lifetime

    NASA Astrophysics Data System (ADS)

    Liu, C.-Y.; Salvat, D.; Adamek, E.

    2014-03-01

    In trap-based lifetime experiments, the key to extrapolating the neutron ?-decay rate is the understanding of non-?-decay losses of the ultracold neutron (UCN) population in the trap. Use of a magnetic trap eliminates the potential for UCN to be lost at surface boundaries. However, these traps also introduce additional systematic errors, such as spin-flip loss when neutrons cross regions of zero field. In addition, the NIST lifetime experiment reported the unexpected presence of quasi-bound, high-energy neutrons that significantly reduced the measured storage lifetime. We discuss the precision required in measuring these sources of non-?-decay losses and strategies to mitigate some of these effects. The discussion will focus on the magneto-gravitational trap used in the UCN? experiment.

  16. Measuring lifetimes of long-lived charged massive particles stopped in LHC detectors

    E-print Network

    Shoji Asai; Koichi Hamaguchi; Satoshi Shirai

    2009-09-28

    Long-lived charged massive particles (CHAMPs) appear in various particle physics models beyond the Standard Model. In this Letter, we discuss the prospects for studying the stopping and decaying events of such long-lived CHAMPs at the LHC detectors, and show that the lifetime measurement (and the study of decay products) is possible with the LHC detectors for a wide range of the lifetime O(0.1)-O(10^{10}) sec, by using periods of no $pp$ collision. Even a short lifetime of order one second can be measured by (i) identifying the stopping event with the online Event Filter, (ii) immediately making a beam-dump signal which stops the $pp$ collision of the LHC, and at the same time (iii) changing the trigger menu to optimize it for the detection of a CHAMP decay in the calorimeter. Other possibilities are also discussed.

  17. Precise measurement of protein interacting fractions with fluorescence lifetime imaging microscopy.

    PubMed

    Walther, Kirstin A; Papke, Björn; Sinn, Maja B; Michel, Kirsten; Kinkhabwala, Ali

    2011-02-01

    Precise quantification of endogenous protein-protein interactions across live cells would be a major boon to biology. Such precise measurement is theoretically possible with fluorescence lifetime imaging microscopy (FLIM) but requires first properly addressing multiple biological, instrumental, statistical, and photophysical challenges. We present a detailed investigation of the last three FLIM-specific challenges. Using an efficient, highly accurate analysis code for time-domain FLIM data that accounts for all significant instrumental artifacts (in part, through use of a parametrized model for the instrument response function) and is rigorously based on both conventional statistics (full lifetime histogram fitting by ?(2) minimization) and novel statistics (single pixel fitting of lifetime populations using "maximum fidelity"), we address multiple photophysical challenges, including the proper side-by-side statistical comparison of fluorophore monoexponentiality, the precise assessment of fluorophore lifetimes and lifetime photostability, and the determination of acceptor dark state fractions. Finally, we demonstrate the feasibility of precise measurement of the interacting fraction of a protein across live cells with FLIM. PMID:21221430

  18. Measurement of the B/s0 lifetime in B/s0 --> K+ K- decays

    SciTech Connect

    Pounder, Nicola Louise; /Oxford U.

    2009-02-01

    A method is presented to simultaneously separate the contributions to a sample of B{sub (s)}{sup 0} {yields} h{sup +}h{sup {prime}-} decays, where h = {pi} or K, and measure the B meson lifetimes in the sample while correcting for the bias in the lifetime distributions due to the hadronic trigger at the CDF experiment. Using 1 fb{sup -1} of data collected at CDF the B{sup 0} lifetime is measured as {tau}{sub B{sup 0}} = 1.558{sub -0.047}{sup +0.050}{sub stat} {+-} 0.028{sub syst} ps, in agreement with the world average measurement. The B{sub s}{sup 0} lifetime in the B{sub s}{sup 0} {yields} K{sup +}K{sup -} decay is measured as {tau}{sub B{sub s}{sup 0} {yields} K{sup +}K{sup -}} = 1.51{sub -0.11}{sup +0.13}{sub stat} {+-} 0.04{sub syst} ps. No difference is observed between the lifetime and other measurements of the average B{sub s}{sup 0} lifetime or the lifetime of the light B{sub s}{sup 0} mass eigenstate determined from B{sub s}{sup 0} {yields} J/{psi}{phi} decays. With the assumptions that B{sub s}{sup 0} {yields} K{sup +}K{sup -} is 100% CP-even and that {tau}{sub B{sub s}{sup 0}} = {tau}{sub B{sup 0}} the width difference in the B{sub s}{sup 0} system is determined as {Delta}{Lambda}{sup CP}/{Lambda} = 0.03{sub -0.15}{sup +0.17}{sub stat} {+-} 0.05{sub syst} using the current world average B{sup 0} lifetime. This is consistent with zero and with the current world average measurement.

  19. Determination of biological activity from fluorescence-lifetime measurements in Saccharomyces cerevisiae

    NASA Astrophysics Data System (ADS)

    Rudek, F.; Baselt, T.; Lempe, B.; Taudt, C.; Hartmann, P.

    2015-03-01

    The importance of fluorescence lifetime measurement as an optical analysis tool is growing. Many applications already exist in order to determine the fluorescence lifetime, but the majority of these require the addition of fluorescence-active substances to enable measurements. Every usage of such foreign materials has an associated risk. This paper investigates the use of auto-fluorescing substances in Saccharomyces cerevisiae (Baker's yeast) as a risk free alternative to fluorescence-active substance enabled measurements. The experimental setup uses a nitrogen laser with a pulse length of 350 ps and a wavelength of 337 nm. The excited sample emits light due to fluorescence of NADH/NADPH and collagen. A fast photodiode collects the light at the output of an appropriate high-pass edge-filter at 400 nm. Fluorescence lifetimes can be determined from the decay of the measurement signals, which in turn characterizes the individual materials and their surrounding environment. Information about the quantity of the fluorescence active substances can also be measured based on the received signal intensity. The correlation between the fluorescence lifetime and the metabolic state of Saccharomyces cerevisiae was investigated and is presented here.

  20. Ratio measurements in oxygen determinations: wavelength ratiometry, lifetime discrimination, and polarization detection

    Microsoft Academic Search

    Yordan Kostov; Govind Rao

    2003-01-01

    In this work we present ratiometric measurements of oxygen concentrations using a dual-emitting dye. Three different methods for ratio measurements in oxygen sensing are employed. The standard wavelength-ratiometric approach is simple to implement, but the sensor response has significant non-linearity. The frequency discrimination of the lifetimes allows for measurements of dual-emission ratio through a single emission filter. In this case

  1. Measurement of the ?(0)(b) lifetime in pp collisions at s?=7 TeV

    E-print Network

    Baringer, Philip S.; Bean, Alice; Benelli, Gabriele; Kenny, R. P. III; Murray, Michael J.; Noonan, Danny; Sanders, Stephen J.; Stringer, Robert W.; Wood, Jeffrey Scott; Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.

    2013-07-26

    A measurement of the ?(0)(b) lifetime using the decay ?(0)(b)?J/?? in protonproton collisions at s?=7 TeV is presented. The data set, corresponding to an integrated luminosity of about 5 fb(?1), was recorded with the CMS experiment at the Large...

  2. Precision Measurement of the Mass and Lifetime of the ?[? over b] Baryon

    E-print Network

    Aaij, R.

    We report on measurements of the mass and lifetime of the ?[- over b] baryon using about 1800 ?[- over b] decays reconstructed in a proton-proton collision data set corresponding to an integrated luminosity of 3.0??fb[superscript ...

  3. Hyperfine predissociation in the B state of iodine investigated through lifetime measurements of individual hyperfine sublevels

    E-print Network

    Boyer, Edmond

    347 Hyperfine predissociation in the B state of iodine investigated through lifetime measurements±5) s-½, pour le niveau 03C5 = 43 de l'état B0+u. Abstract. 2014 Iodine exhibits the phenomenon. In this respect, studies of predis- sociation phenomena are of special interest. The case of the iodine B state

  4. An Undergraduate Experiment on Nuclear Lifetime Measurement Using the Doppler Effect

    ERIC Educational Resources Information Center

    Campbell, J. L.; And Others

    1972-01-01

    While designed for a senior undergraduate laboratory, the experiment illustrates the principles involved in the various Doppler techniques currently used in nuclear lifetime studies and demonstrates the versatility of the Ge(Li) detector in applications other than direct energy or intensity measurement. (Author/TS)

  5. Precision Measurements of Atomic Lifetimes and Hyperfine Energies in Alkali Like Systems

    Microsoft Academic Search

    Carol E

    2005-01-01

    Financial support of this research project has lead to advances in the study of atomic structure through precision measurements of atomic lifetimes, energy splittings, and transitions energies. The interpretation of data from many areas of physics and chemistry requires an accurate understanding of atomic structure. For example, scientists in the fields of astrophysics, geophysics, and plasma fusion depend on transition

  6. Measurement of the Masses and Lifetimes of B Hadrons at the Tevatron

    E-print Network

    P. Catastini; for the CDF Collaboration; D0 Collaboration

    2006-05-15

    The latest results for the B Hadron sector at the Tevatron Collider are summarized. The properties of B Hadrons can be precisely measured at the Tevatron. In particularly we will focus on the masses and lifetimes. The new Tevatron results for the CP violation in B Hadrons will be also discussed.

  7. Measurement of the B0S meson lifetime using semileptonic decays

    Microsoft Academic Search

    F. Abe; H. Akimoto; A. Akopian; M. G. Albrow; A. Amadon; S. R. Amendolia; D. Amidei; J. Antos; S. Aota; G. Apollinari; T. Arisawa; T. Asakawa; W. Ashmanskas; M. Atac; P. Azzi-Bacchetta; N. Bacchetta; S. Bagdasarov; M. W. Bailey; P. de Barbaro; A. Barbaro-Galtieri; V. E. Barnes; B. A. Barnett; M. Barone; G. Bauer; T. Baumann; F. Bedeschi; S. Behrends; S. Belforte; G. Bellettini; J. Bellinger; D. Benjamin; J. Bensinger; A. Beretvas; J. P. Berge; J. Berryhill; S. Bertolucci; S. Bettelli; B. Bevensee; A. Bhatti; K. Biery; C. Bigongiari; M. Binkley; D. Bisello; R. E. Blair; C. Blocker; S. Blusk; A. Bodek; W. Bokhari; G. Bolla; Y. Bonushkin; D. Bortoletto; J. Boudreau; L. Breccia; C. Bromberg; N. Bruner; R. Brunetti; E. Buckley-Geer; H. S. Budd; K. Burkett; G. Busetto; A. Byon-Wagner; K. L. Byrum; M. Campbell; A. Caner; W. Carithers; D. Carlsmith; J. Cassada; A. Castro; D. Cauz; A. Cerri; P. S. Chang; H. Y. Chao; J. Chapman; M.-T. Cheng; M. Chertok; G. Chiarelli; C. N. Chiou; F. Chlebana; L. Christofek; M. L. Chu; S. Cihangir; A. G. Clark; M. Cobal; E. Cocca; M. Contreras; J. Conway; J. Cooper; M. Cordelli; D. Costanzo; C. Couyoumtzelis; D. Cronin-Hennessy; R. Culbertson; D. Dagenhart; T. Daniels; F. Dejongh; S. dell'agnello; M. dell'orso; R. Demina; L. Demortier; M. Deninno; P. F. Derwent; T. Devlin; J. R. Dittmann; S. Donati; J. Done; T. Dorigo; N. Eddy; K. Einsweiler; J. E. Elias; R. Ely; E. Engels; W. Erdmann; D. Errede; S. Errede; Q. Fan; R. G. Feild; Z. Feng; C. Ferretti; I. Fiori; B. Flaugher; G. W. Foster; M. Franklin; J. Freeman; J. Friedman; Y. Fukui; S. Gadomski; S. Galeotti; M. Gallinaro; O. Ganel; M. Garcia-Sciveres; A. F. Garfinkel; C. Gay; S. Geer; D. W. Gerdes; P. Giannetti; N. Giokaris; P. Giromini; G. Giusti; M. Gold; A. Gordon; A. T. Goshaw; Y. Gotra; K. Goulianos; H. Grassmann; L. Groer; C. Grosso-Pilcher; G. Guillian; J. Guimaraes da Costa; R. S. Guo; C. Haber; E. Hafen; S. R. Hahn; T. Handa; R. Handler; F. Happacher; K. Hara; A. D. Hardman; R. M. Harris; F. Hartmann; J. Hauser; E. Hayashi; J. Heinrich; W. Hao; B. Hinrichsen; K. D. Hoffman; M. Hohlmann; C. Holck; R. Hollebeek; L. Holloway; Z. Huang; B. T. Huffman; R. Hughes; J. Huston; J. Huth; H. Ikeda; M. Incagli; J. Incandela; G. Introzzi; J. Iwai; Y. Iwata; E. James; H. Jensen; U. Joshi; E. Kajfasz; H. Kambara; T. Kamon; T. Kaneko; K. Karr; H. Kasha; Y. Kato; T. A. Keaffaber; K. Kelley; R. D. Kennedy; R. Kephart; D. Kestenbaum; D. Khazins; T. Kikuchi; B. J. Kim; H. S. Kim; S. H. Kim; Y. K. Kim; L. Kirsch; S. Klimenko; D. Knoblauch; P. Koehn; A. Köngeter; K. Kondo; J. Konigsberg; K. Kordas; A. Korytov; E. Kovacs; W. Kowald; J. Kroll; M. Kruse; S. E. Kuhlmann; E. Kuns; K. Kurino; T. Kuwabara; A. T. Laasanen; S. Lami; S. Lammel; J. I. Lamoureux; M. Lancaster; M. Lanzoni; G. Latino; T. Lecompte; S. Leone; J. D. Lewis; M. Lindgren; T. M. Liss; J. B. Liu; Y. C. Liu; N. Lockyer; O. Long; C. Loomis; M. Loreti; D. Lucchesi; P. Lukens; S. Lusin; J. Lys; K. Maeshima; P. Maksimovic; M. Mangano; M. Mariotti; J. P. Marriner; G. Martignon; A. Martin; J. A. Matthews; P. Mazzanti; K. McFarland; P. McIntyre; P. Melese; M. Menguzzato; A. Menzione; E. Meschi; S. Metzler; C. Miao; T. Miao; G. Michail; R. Miller; H. Minato; S. Miscetti; M. Mishina; S. Miyashita; N. Moggi; E. Moore; Y. Morita; A. Mukherjee; T. Muller; P. Murat; S. Murgia; M. Musy; H. Nakada; T. Nakaya; I. Nakano; C. Nelson; D. Neuberger; C. Newman-Holmes; C.-Y. P. Ngan; L. Nodulman; A. Nomerotski; S. H. Oh; T. Ohmoto; T. Ohsugi; R. Oishi; M. Okabe; T. Okusawa; J. Olsen; C. Pagliarone; R. Paoletti; V. Papadimitriou; S. P. Pappas; N. Parashar; A. Parri; J. Patrick; G. Pauletta; M. Paulini; A. Perazzo; L. Pescara; M. D. Peters; T. J. Phillips; G. Piacentino; M. Pillai; K. T. Pitts; R. Plunkett; A. Pompos; L. Pondrom; J. Proudfoot; F. Ptohos; G. Punzi; K. Ragan; D. Reher; M. Reischl; A. Ribon; F. Rimondi; L. Ristori; W. J. Robertson; T. Rodrigo; S. Rolli; L. Rosenson; R. Roser; T. Saab; W. K. Sakumoto; D. Saltzberg; A. Sansoni; L. Santi; H. Sato; P. Schlabach; E. E. Schmidt; M. P. Schmidt; A. Scott; A. Scribano; S. Segler; S. Seidel; Y. Seiya; F. Semeria; T. Shah; M. D. Shapiro; N. M. Shaw; P. F. Shepard; T. Shibayama; M. Shimojima; M. Shochet; J. Siegrist; A. Sill; P. Sinervo; P. Singh; K. Silwa; C. Smith; F. D. Snider; J. Spalding; T. Speer; P. Sphicas; F. Spinella; M. Spiropulu; L. Spiegel; L. Stanco; J. Steele; A. Stefanini; R. Ströhmer; Strologas J; F. Strumia; D. Stuart; K. Sumorok; J. Suzuki; T. Suzuki; T. Takahashi; T. Takano; R. Takashima; K. Takikawa; M. Tanaka; B. Tannenbaum; F. Tartarelli; W. Taylor; M. Tecchio; P. K. Teng; Y. Teramoto; K. Terashi; S. Tether; D. Theriot; T. L. Thomas; R. Thurman-Keup; M. Timko; P. Tipton; A. Titov; S. Tkaczyk; D. Toback; K. Tollefson; A. Tollestrup; H. Toyoda; W. Trischuk; J. F. de Troconiz; S. Truitt; J. Tseng; N. Turini; T. Uchida

    1999-01-01

    The lifetime of the B0S meson is measured using the semileptonic decay B0S-->D-Sl+nuX. The data sample consists of about 110 pb-1 of pp¯ collisions at s=1.8 TeV collected by the CDF detector at Fermilab. Four different D-S decay modes are reconstructed resulting in approximately 600 D-Sl+ signal events. The B0S meson lifetime is determined to be tau(B0S)=(1.36+\\/-0.09+0.06-0.05) ps, where the

  8. Saturation of radiation trapping and lifetime measurements in three-level laser crystals.

    PubMed

    Chen, Ching-Hsu; Wu, Yue-Heng; Fan, Cheng-Ping; Wei, Tai-Hei

    2012-11-01

    In this study, we take the pump rate into consideration for the first time to give a theoretical description of radiation trapping in three-level systems. We numerically verify that under strong pumping, the population of the ground state is depleted, which leads to saturation of the radiation trapping within the pumped region. This saturation inevitably clamps the lifetime lengthening that is experimentally verified on a 0.05 at% thin ruby crystal based on the axial pinhole method. Our model is confirmed to be valid in lifetime measurement when the ruby fluorescence is collected from both the pumped and the unpumped regions. PMID:23187380

  9. A magneto-gravitational neutron trap for the measurement of the neutron lifetime

    NASA Astrophysics Data System (ADS)

    Salvat, Daniel J.

    Neutron decay is the simplest example of nuclear beta-decay. The mean decay lifetime is a key input for predicting the abundance of light elements in the early universe. A precise measurement of the neutron lifetime, when combined with other neutron decay observables, can test for physics beyond the standard model in a way that is complimentary to, and potentially competitive with, results from high energy collider experiments. Many previous measurements of the neutron lifetime used ultracold neutrons (UCN) confined in material bottles. In a material bottle experiment, UCN are loaded into the apparatus, stored for varying times, and the surviving UCN are emptied and counted. These measurements are in poor agreement with experiments that use neutron beams, and new experiments are needed to resolve the discrepancy and precisely determine the lifetime. Here we present an experiment that uses a bowl-shaped array of NdFeB magnets to confine neutrons without material wall interactions. The trap shape is designed to rapidly remove higher energy UCN that might slowly leak from the top of the trap, and can facilitate new techniques to count surviving UCN within the trap. We review the scientific motivation for a precise measurement of the neutron lifetime, and present the commissioning of the trap. Data are presented using a vanadium activation technique to count UCN within the trap, providing an alternative method to emptying neutrons from the trap and into a counter. Potential systematic effects in the experiment are then discussed and estimated using analytical and numerical techniques. We also investigate solid nitrogen-15 as a source of UCN using neutron time-of-flight spectroscopy. We conclude with a discussion of forthcoming research and development for UCN detection and UCN sources.

  10. Measurement of the average lifetime of b-hadrons in Z decays

    Microsoft Academic Search

    M. Acciarri; O. Adriani; M. Aguilar-Benitez; S. Ahlen; J. Alcaraz; G. Alemanni; J. Allaby; A. Aloisio; M. G. Alviggi; G Ambrosi; H Anderhub; V. P Andreev; T Angelescu; F Anselmo; A Arefiev; T Azemoon; T Aziz; P Bagnaia; L Baksay; R. C Ball; Sw. Banerjee; K Banicz; A Barczyk; R Barillère; L Barone; P Bartalini; A Baschirotto; M Basile; R Battiston; A Bay; F Becattini; U Becker; F Behner; J Berdugo; P Berges; B Bertucci; B. L Betev; S Bhattacharya; M Biasini; A Biland; G. M Bilei; J. J Blaising; S. C Blyth; G. J Bobbink; R Bock; A Böhm; L Boldizsar; B Borgia; D Bourilkov; M Bourquin; D Boutigny; S Braccini; J. G Branson; V Brigljevic; I. C Brock; A Buffini; A Buijs; W. J. Burger; J Busenitz; X. D Cai; M Campanelli; M Capell; G Cara Romeo; G Carlino; A. M Cartacci; J Casaus; G Castellini; F Cavallari; N Cavallo; C Cecchi; M Cerrada; F Cesaroni; M Chamizo; Y. H Chang; U. K Chaturvedi; S. V Chekanov; M Chemarin; A Chen; G Chen; H. F Chen; H. S Chen; M Chen; G Chiefari; C. Y Chien; L Cifarelli; F Cindolo; C Civinini; I Clare; R Clare; H. O Cohn; G Coignet; A. P Colijn; N Colino; S Costantini; F Cotorobai; B de la Cruz; A Csilling; T. S Dai; R D'Alessandro; R de Asmundis; A Degré; K Deiters; P Denes; F DeNotaristefani; D DiBitonto; M Diemoz; D van Dierendonck; F Di Lodovico; C Dionisi; M Dittmar; A Dominguez; A Doria; M. T Dova; E Drago; D Duchesneau; P Duinker; I Duran; S Dutta; S Easo; Yu Efremenko; H El Mamouni; A Engler; F. J Eppling; F. C Erné; J. P Ernenwein; P Extermann; M Fabre; R Faccini; S Falciano; A Favara; J Fay; O Fedin; M Felcini; B Fenyi; T Ferguson; D Fernandez; F Ferroni; H Fesefeldt; E Fiandrini; J. H Field; F Filthaut; P. H Fisher; I Fisk; G Forconi; L Fredj; K Freudenreich; C Furetta; Yu Galaktionov; S. N Ganguli; P Garcia-Abia; S. Gentile; J Gerald; N Gheordanescu; S. Goldfarb; J Goldstein; Z. F Gong; A Gougas; G Gratta; M. W Gruenewald; V. K Gupta; A Gurtu; L. J Gutay; B Hartmann; A Hasan; D Hatzifotiadou; T Hebbeker; A Hervé; W. C van Hoek; H Hofer; S. J Hong; H Hoorani; S. R Hou; G Hu; V Innocente; K Jenkes; B. N Jin; L. W Jones; P de Jong; I Josa-Mutuberria; R. A. Khan; D Kamrad; Yu Kamyshkov; J. S Kapustinsky; Y Karyotakis; M Kaur; M. N Kienzle-Focacci; D Kim; J. K Kim; S. C Kim; Y. G Kim; W. W Kinnison; A Kirkby; D Kirkby; J Kirkby; D Kiss; W Kittel; A Klimentov; A. C König; A Kopp; I Korolko; V Koutsenko; R. W Kraemer; W Krenz; A Kunin; P. Ladron de Guevara; G Landi; C Lapoint; K Lassila-Perini; P Laurikainen; M Lebeau; A Lebedev; P. Lecomte; P. Le Coultre; H. J Lee; C Leggett; J. M Le Goff; R Leiste; E Leonardi; P Levtchenko; C Li; C. H Lin; W. T Lin; F. L Linde; L Lista; Z. A Liu; W Lohmann; E Longo; W Lu; Y. S Lu; K Lübelsmeyer; C Luci; D Luckey; L Luminari; W Lustermann; W. G Ma; M Maity; G Majumder; L Malgeri; A Malinin; C Maña; D Mangeol; S Mangla; P Marchesini; A Marin; J. P Martin; F Marzano; G. G. G Massaro; D McNally; S Mele; L Merola; M Meschini; W. J Metzger; M von der Mey; Y Mi; A Mihul; A. J. W van Mil; H Milcent; G Mirabelli; J Mnich; P Molnar; B Monteleoni; R Moore; S Morganti; T Moulik; R Mount; F Muheim; A. J. M Muijs; S Nahn; M Napolitano; F Nessi-Tedaldi; H Newman; T Niessen; A. Nisati; H Nowak; Y. D Oh; H Opitz; G Organtini; R Ostonen; C Palomares; D Pandoulas; S Paoletti; P Paolucci; I. H. Park; G. Passaleva; S Patricelli; T Paul; M Pauluzzi; C Paus; F Pauss; D Peach; Y. J Pei; S Pensotti; D Perret-Gallix; B Petersen; S Petrak; A Pevsner; D Piccolo; M Pieri; P. A Piroué; E Pistolesi; V Plyaskin; M Pohl; V Pojidaev; H Postema; N Produit; D Prokofiev; G Rahal-Callot; N Raja; P. G Rancoita; M Rattaggi; G Raven; P Razis; K Read; D Ren; M Rescigno; S Reucroft; T van Rhee; S Riemann; K Riles; O Rind; A Robohm; J Rodin; B. P Roe; L Romero; S Rosier-Lees; Ph Rosselet; W van Rossum; S Roth; J. A Rubio; D Ruschmeier; H Rykaczewski; J Salicio; E Sanchez; M. P Sanders; M. E Sarakinos; S Sarkar; G Sauvage; C Schäfer; V Schegelsky; S Schmidt-Kaerst; D Schmitz; M Schneegans; N Scholz; H Schopper; D. J Schotanus; J Schwenke; G Schwering; C Sciacca; D Sciarrino; L Servoli; S Shevchenko; N Shivarov; V Shoutko; J Shukla; E Shumilov; A Shvorob; T Siedenburg; D Son; V Soulimov; B Smith; P Spillantini; M Steuer; D. P Stickland; H Stone; B Stoyanov; A Straessner; K. Sudhakar; G Sultanov; L. Z Sun; G. F Susinno; H Suter; J. D Swain; X. W Tang; L Tauscher; L Taylor; Samuel C. C Ting; S. M Ting; S. C Tonwar; J Tóth; C Tully; H Tuchscherer; K. L Tung; Y Uchida; J Ulbricht; U Uwer; E Valente; R. T Van de Walle; G Vesztergombi; I Vetlitsky; G Viertel; M Vivargent; R Völkert; H. Vogt; I Vorobiev; A. Vorvolakos; M Wadhwa; W Wallraff; J. C Wang; X. L Wang; Z. M Wang; A Weber; S. Wynhoff; J Xu; Z. Z Xu; B. Z Yang; C. G Yang; X. Y Yao; J. B Ye; S. C Yeh; J. M You; An Zalite; Yu Zalite; P Zemp; Y Zeng; Z Zhang; B Zhou; G. Y. Zhu; R. Y Zhu; A Zichichi; F Ziegler

    1998-01-01

    We present a measurement of the average b-hadron lifetime ?b at the e+e?collider LEP. Using hadronic Z decays collected in the period from 1991 to 1994, two independent analyses have been performed. In the first one, the b-decay position is reconstructed as a secondary vertex of hadronic b-decay particles. The second analysis is an updated measurement of ?b using the

  11. Measurement of the B and B¯ 0 Meson Lifetimes Using Semileptonic Decays

    Microsoft Academic Search

    F. Abe; H. Akimoto; A. Akopian; M. G. Albrow; S. R. Amendolia; D. Amidei; J. Antos; C. Anway-Wiese; S. Aota; G. Apollinari; T. Asakawa; W. Ashmanskas; M. Atac; F. Azfar; P. Azzi-Bacchetta; N. Bacchetta; W. Badgett; S. Bagdasarov; M. W. Bailey; J. Bao; P. de Barbaro; A. Barbaro-Galtieri; V. E. Barnes; B. A. Barnett; E. Barzi; G. Bauer; T. Baumann; F. Bedeschi; S. Behrends; S. Belforte; G. Bellettini; J. Bellinger; D. Benjamin; J. Benlloch; J. Bensinger; D. Benton; A. Beretvas; J. P. Berge; J. Berryhill; S. Bertolucci; A. Bhatti; K. Biery; M. Binkley; D. Bisello; R. E. Blair; C. Blocker; A. Bodek; W. Bokhari; V. Bolognesi; D. Bortoletto; J. Boudreau; L. Breccia; C. Bromberg; N. Bruner; E. Buckley-Geer; H. S. Budd; K. Burkett; G. Busetto; A. Byon-Wagner; K. L. Byrum; J. Cammerata; C. Campagnari; M. Campbell; A. Caner; W. Carithers; D. Carlsmith; A. Castro; D. Cauz; Y. Cen; F. Cervelli; P. Auchincloss; H. Y. Chao; J. Chapman; M.-T. Cheng; G. Chiarelli; T. Chikamatsu; C. N. Chiou; L. Christofek; S. Cihangir; A. G. Clark; M. Cobal; M. Contreras; J. Conway; J. Cooper; M. Cordelli; C. Couyoumtzelis; D. Crane; D. Cronin-Hennessy; R. Culbertson; J. D. Cunningham; T. Daniels; F. Dejongh; S. Delchamps; S. dell'Agnello; M. dell'Orso; L. Demortier; B. Denby; M. Deninno; P. F. Derwent; T. Devlin; J. R. Dittmann; S. Donati; J. Done; T. Dorigo; A. Dunn; N. Eddy; K. Einsweiler; J. E. Elias; R. Ely; E. Engels Jr.; D. Errede; S. Errede; Q. Fan; I. Fiori; B. Flaugher; G. W. Foster; M. Franklin; M. Frautschi; J. Freeman; J. Friedman; T. A. Fuess; Y. Fukui; S. Funaki; G. Gagliardi; S. Galeotti; M. Gallinaro; M. Garcia-Sciveres; A. F. Garfinkel; C. Gay; S. Geer; D. W. Gerdes; P. Giannetti; N. Giokaris; P. Giromini; L. Gladney; D. Glenzinski; M. Gold; J. Gonzalez; A. Gordon; A. T. Goshaw; K. Goulianos; H. Grassmann; L. Groer; C. Grosso-Pilcher; G. Guillian; R. S. Guo; C. Haber; E. Hafen; S. R. Hahn; R. Handler; R. M. Hans; K. Hara; A. D. Hardman; B. Harral; R. M. Harris; S. A. Hauger; J. Hauser; C. Hawk; E. Hayashi; J. Heinrich; K. D. Hoffman; M. Hohlmann; C. Holck; R. Hollebeek; L. Holloway; A. Hölscher; S. Hong; G. Houk; P. Hu; B. T. Huffman; R. Hughes; J. Huston; J. Huth; J. Hylen; H. Ikeda; M. Incagli; J. Incandela; G. Introzzi; J. Iwai; Y. Iwata; H. Jensen; U. Joshi; R. W. Kadel; E. Kajfasz; T. Kamon; T. Kaneko; K. Karr; H. Kasha; Y. Kato; T. A. Keaffaber; L. Keeble; K. Kelley; R. D. Kennedy; R. Kephart; P. Kesten; D. Kestenbaum; R. M. Keup; H. Keutelian; F. Keyvan; B. Kharadia; B. J. Kim; D. H. Kim; H. S. Kim; S. B. Kim; S. H. Kim; Y. K. Kim; L. Kirsch; P. Koehn; K. Kondo; J. Konigsberg; S. Kopp; K. Kordas; W. Koska; E. Kovacs; W. Kowald; M. Krasberg; J. Kroll; M. Kruse; T. Kuwabara; S. E. Kuhlmann; E. Kuns; A. T. Laasanen; N. Labanca; S. Lammel; J. I. Lamoureux; T. Lecompte; S. Leone; J. D. Lewis; P. Limon; M. Lindgren; T. M. Liss; N. Lockyer; O. Long; C. Loomis; M. Loreti; J. Lu; D. Lucchesi; P. Lukens; S. Lusin; J. Lys; K. Maeshima; A. Maghakian; P. Maksimovic; M. Mangano; J. Mansour; M. Mariotti; J. P. Marriner; A. Martin; J. A. Matthews; R. Mattingly; P. McIntyre; P. Melese; A. Menzione; E. Meschi; S. Metzler; C. Miao; G. Michail; R. Miller; H. Minato; S. Miscetti; M. Mishina; H. Mitsushio; T. Miyamoto; S. Miyashita; Y. Morita; J. Mueller; A. Mukherjee; T. Muller; P. Murat; H. Nakada; I. Nakano; C. Nelson; D. Neuberger; C. Newman-Holmes; M. Ninomiya; L. Nodulman; S. H. Oh; K. E. Ohl; T. Ohmoto; T. Ohsugi; R. Oishi; M. Okabe; T. Okusawa; R. Oliver; J. Olsen; C. Pagliarone; R. Paoletti; V. Papadimitriou; S. P. Pappas; A. Parri; J. Patrick; G. Pauletta; M. Paulini; A. Perazzo; L. Pescara; M. D. Peters; T. J. Phillips; G. Piacentino; M. Pillai; K. T. Pitts; R. Plunkett; L. Pondrom; J. Proudfoot; F. Ptohos; G. Punzi; K. Ragan; A. Ribon; F. Rimondi; L. Ristori; W. J. Robertson; T. Rodrigo; S. Rolli; J. Romano; L. Rosenson; R. Roser; W. K. Sakumoto; D. Saltzberg; A. Sansoni; L. Santi; H. Sato; V. Scarpine; P. Schlabach; E. E. Schmidt; M. P. Schmidt; A. Scribano; S. Segler; S. Seidel; Y. Seiya; G. Sganos; A. Sgolacchia; M. D. Shapiro; N. M. Shaw; Q. Shen; P. F. Shepard; M. Shimojima; M. Shochet; J. Siegrist; A. Sill; P. Sinervo; P. Singh; J. Skarha; K. Sliwa; F. D. Snider; T. Song; J. Spalding; P. Sphicas; F. Spinella; M. Spiropulu; L. Spiegel; L. Stanco; J. Steele; A. Stefanini; K. Strahl; J. Strait; R. Ströhmer; D. Stuart; G. Sullivan; A. Soumarokov; K. Sumorok; J. Suzuki; T. Takada; T. Takahashi; T. Takano; K. Takikawa; N. Tamura; F. Tartarelli; W. Taylor; P. K. Teng; Y. Teramoto; S. Tether; D. Theriot; T. L. Thomas; R. Thun; M. Timko; P. Tipton; A. Titov; S. Tkaczyk; D. Toback; K. Tollefson; A. Tollestrup; J. Tonnison; J. F. de Troconiz; S. Truitt; J. Tseng; N. Turini; T. Uchida; N. Uemura; F. Ukegawa; G. Unal; S. C. van den Brink; S. Vejcik III; G. Velev; R. Vidal; M. Vondracek; D. Vucinic; R. G. Wagner

    1996-01-01

    The lifetimes of the B- and B¯ 0 mesons are measured using the partially reconstructed semileptonic decays B¯-->Dl-nu¯X, where D is either a D0 or D*+ meson. The data were collected by the CDF detector at the Fermilab Tevatron collider during 1992-1993 and correspond to 19.3 pb-1 of p¯p collisions at s = 1.8 TeV. We measure the decay length

  12. Wafer Preparation and Iodine-Ethanol-Ethanol Passivation Procedure for Reproducible Minority-Carrier Lifetime Measurement: Preprint

    SciTech Connect

    Sopori, B.; Rupnowski, P.; Appel, J.; Mehta, V.; Li, C.; Johnston, S.

    2008-05-01

    This paper describes reasons that lifetime measurments may be irreproducible using iodine-in-ethanol (I-E) passivation. Possible factors include the strength of the iodine in ethanol solution, wafer cleaning procedures, influence of wafer container during lifetime measurement, and stability of I-E.

  13. CMOS direct time interval measurement of long-lived luminescence lifetimes.

    PubMed

    Yao, Lei; Yung, Ka Yi; Cheung, Maurice C; Chodavarapu, Vamsy P; Bright, Frank V

    2011-01-01

    We describe a Complementary Metal-Oxide Semiconductor (CMOS) Direct Time Interval Measurement (DTIM) Integrated Circuit (IC) to detect the decay (fall) time of the luminescence emission when analyte-sensitive luminophores are excited with an optical pulse. The CMOS DTIM IC includes 14 × 14 phototransistor array, transimpedance amplifier, regulated gain amplifier, fall time detector, and time-to-digital convertor. We examined the DTIM system to measure the emission lifetime of oxygen-sensitive luminophores tris(4,7-diphenyl-1, 10-phenanthroline) ruthenium(II) ([Ru(dpp)(3)](2+)) encapsulated in sol-gel derived xerogel thin-films. The DTIM system fabricated using TSMC 0.35 ?m process functions to detect lifetimes from 4 ?s to 14.4 ?s but can be tuned to detect longer lifetimes. The system provides 8-bit digital output proportional to lifetimes and consumes 4.5 mW of power with 3.3 V DC supply. The CMOS system provides a useful platform for the development of reliable, robust, and miniaturized optical chemical sensors. PMID:22254237

  14. Electroweak Measurements in Electron-Positron Collisions at W-Boson-Pair Energies at LEP

    E-print Network

    Schael, S; Bruneliere, R; Buskulic, D; De Bonis, I; Decamp, D; Ghez, P; Goy, C; Jezequel, S; Lees, J P; Lucotte, A; Martin, F; Merle, E; Minard, M N; Nief, J Y; Odier, P; Pietrzyk, B; Trocme, B; Bravo, S; Casado, M P; Chmeissani, M; Comas, P; Crespo, J M; Fernandez, E; Fernandez-Bosman, M; Garrido, Ll; Grauges, E; Juste, A; Martinez, M; Merino, G; Miquel, R; Mir, Ll. M; Orteu, S; Pacheco, A; Park, I C; Perlas, J; Riu, I; Ruiz, H; Sanchez, F; Colaleo, A; Creanza, D; De Filippis, N; De Palma, M; Iaselli, G; Maggi, G; Maggi, M; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Bazarko, A; Becker, U; Boix, G; Bird, F; Blucher, E; Bonvicini, B; Bright-Thomas, P; Barklow, T; Buchmuller, O; Cattaneo, M; Cerutti, F; Ciulli, V; Clerbaux, B; Drevermann, H; Forty, R W; Frank, M; Greening, T C; Hagelberg, R; Halley, A W; Gianotti, F; Girone, M; Hansen, J B; Harvey, J; Jacobsen, R; Hutchcroft, D E; Janot, P; Jost, B; Knobloch, J; Kado, M; Lehraus, I; Lazeyras, P; Maley, P; Mato, P; May, J; Moutoussi, A; Pepe-Altarelli, M; Ranjard, F; Rolandi, L; Schlatter, D; Schmitt, B; Schneider, O; Tejessy, W; Teubert, F; Tomalin, I R; Tournefier, E; Veenhof, R; Valassi, A; Wiedenmann, W; Wright, A E; Ajaltouni, Z; Badaud, F; Chazelle, G; Deschamps, O; Dessagne, S; Falvard, A; Ferdi, C; Fayolle, D; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Pascolo, J M; Perret, P; Podlyski, F; Bertelsen, H; Fernley, T; Hansen, J D; Hansen, J R; Hansen, P H; Kraan, A C; Lindahl, A; Mollerud, R; Nilsson, B S; Rensch, B; Waananen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, E; Siotis, I; Vayaki, A; Zachariadou, K; Blondel, A; Bonneaud, G; Brient, J C; Machefert, F; Rouge, A; Rumpf, M; Swynghedauw, M; Tanaka, R; Verderi, M; Videau, H; Ciulli, V; Focardi, E; Parrini, G; Zachariadou, K; Corden, M; Georgiopoulos, C; Antonelli, A; Antonelli, M; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Cerutti, F; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, G P; Passalacqua, L; Picchi, P; Colrain, P; Have, I. ten; Hughes, I S; Kennedy, J; Knowles, I G; Lynch, J G; Morton, W T; Negus, P; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Thompson, A S; Turnbull, R M; Wasserbaech, S; Buchmuller, O; Cavanaugh, R; Dhamotharan, S; Geweniger, C; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Sommer, J; Stenzel, H; Tittel, K; Werner, W; Wunsch, M; Beuselinck, R; Binnie, D M; Cameron, W; Davies, G; Dornan, P J; Goodsir, S; Marinelli, N; Martin, E B; Nash, J; Nowell, J; Rutherford, S A; Sedgbeer, J K; Thompson, J C; White, R; Williams, M D; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Bouhova-Thacker, E; Bowdery, C K; Buck, P G; Clarke, D P; Ellis, G; Finch, A J; Foster, F; Hughes, G; Jones, R.W L; Keemer, N R; Pearson, M R; Robertson, N A; Sloan, T; Smizanska, M; Snow, S W; Williams, M I; van der Aa, O; Delaere, C; Leibenguth, G; Lemaitre, V; Bauerdick, L.A T; Blumenschein, U; van Gemmeren, P; Giehl, I; Holldorfer, F; Jakobs, K; Kasemann, M; Kayser, F; Kleinknecht, K; Muller, A S; Quast, G; Renk, B; Rohne, E; Sander, H G; Schmeling, S; Wachsmuth, H; Wanke, R; Zeitnitz, C; Ziegler, T; Aubert, J J; Benchouk, C; Bonissent, A; Carr, J; Coyle, P; Curtil, C; Ealet, A; Etienne, F; Fouchez, D; Motsch, F; Payre, P; Rousseau, D; Tilquin, A; Talby, M; Thulasidas, M; Aleppo, M; Antonelli, M; Ragusa, F; Buscher, V; David, A; Dietl, H; Ganis, G; Huttmann, K; Lutjens, G; Mannert, C; Manner, W; Moser, H G; Settles, R; Seywerd, H; Stenzel, H; Villegas, M; Wiedenmann, W; Wolf, G; Azzurri, P; Boucrot, J; Callot, O; Chen, S; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, Ph; Jacholkowska, A; Le Diberder, F; Lefrancois, J; Mutz, A M; Schune, M H; Serin, L; Veillet, J J; Videau, I; Zerwas, D; Azzurri, P; Bagliesi, G; Bettarini, S; Boccali, T; Bozzi, C; Calderini, G; Dell'Orso, R; Fantechi, R; Ferrante, I; Fidecaro, F; Foa, L; Giammanco, A; Giassi, A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, F; Rizzo, G; Sanguinetti, G; Sciaba, A; Sguazzoni, G; Spagnolo, P; Steinberger, J; Tenchini, R; Vannini, C; Venturi, A; Verdini, P G; Awunor, O; Blair, G A; Cowan, G; Garcia-Bellido, A; Green, M G; Medcalf, T; Misiejuk, A; Strong, J A; Teixeira-Dias, P; Botterill, D R; Clifft, R W; Edgecock, T R; Edwards, M; Haywood, S J; Norton, P R; Tomalin, I R; Ward, J J; Bloch-Devaux, B; Boumediene, D; Colas, P; Emery, S; Fabbro, B; Kozanecki, W; Lancon, E; Lemaire, M C; Locci, E; Perez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Tuchming, B; Vallage, B; Black, S N; Dann, J H; Kim, H Y; Konstantinidis, N; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Cartwright, S

    2013-01-01

    Electroweak measurements performed with data taken at the electron-positron collider LEP at CERN from 1995 to 2000 are reported. The combined data set considered in this report corresponds to a total luminosity of about 3~fb$^{-1}$ collected by the four LEP experiments ALEPH, DELPHI, L3 and OPAL, at centre-of-mass energies ranging from $130~GeV$ to $209~GeV$. Combining the published results of the four LEP experiments, the measurements include total and differential cross-sections in photon-pair, fermion-pair and four-fermion production, the latter resulting from both double-resonant WW and ZZ production as well as singly resonant production. Total and differential cross-sections are measured precisely, providing a stringent test of the Standard Model at centre-of-mass energies never explored before in electron-positron collisions. Final-state interaction effects in four-fermion production, such as those arising from colour reconnection and Bose-Einstein correlations between the two W decay systems arising ...

  15. Application of Positron Doppler Broadening Spectroscopy to the Measurement of the Uniformity of Composite Materials

    SciTech Connect

    Quarles, C. A.; Sheffield, Thomas; Stacy, Scott; Yang, Chun [Department of Physics and Astronomy, Texas Christian University, Fort Worth TX 76129 (United States)

    2009-03-10

    The uniformity of rubber-carbon black composite materials has been investigated with positron Doppler Broadening Spectroscopy (DBS). The number of grams of carbon black (CB) mixed into one hundred grams of rubber, phr, is used to characterize a sample. A typical concentration for rubber in tires is 50 phr. The S parameter measured by DBS has been found to depend on the phr of the sample as well as the type of rubber and carbon black. The variation in carbon black concentration within a surface area of about 5 mm diameter can be measured by moving a standard Na-22 or Ge-68 positron source over an extended sample. The precision of the concentration measurement depends on the dwell time at a point on the sample. The time required to determine uniformity over an extended sample can be reduced by running with much higher counting rate than is typical in DBS and correcting for the systematic variation of S parameter with counting rate. Variation in CB concentration with mixing time at the level of about 0.5% has been observed.

  16. Positron Annihilation Spectroscopy Of High Performance Polymer Films Under CO{sub 2} Pressure

    SciTech Connect

    Quarles, C. A. [Texas Christian University, Fort Worth TX 76109 (United States); Klaehn, John R.; Peterson, Eric S. [Idaho National Laboratory, Idaho Falls ID 83415-2208 (United States); Urban-Klaehn, Jagoda M. [Pajarito Scientific Corporation, Idaho Falls ID 83404 (United States)

    2011-06-01

    Positron annihilation Lifetime and Doppler broadening measurements are reported for six polymer films as a function of carbon dioxide (CO{sub 2}) absolute pressure ranging from 0 to 45 psi. Since the polymer films were thin and did not absorb all positrons, corrections were made in the lifetime analysis for the absorption of positrons in the positron source and sample holder using the Monte Carlo transport code MCNP. The studied polymers are found to behave differently from each other. Some polymers form positronium and others, such as the polyimide structures, do not. For those polymers that form positronium an interpretation in terms of free volume is possible; for those that don't form positronium, further work is needed to determine how best to describe the behavior in terms of the bulk positron annihilation parameters. A few of the studied polymers exhibit changes in positron lifetime and intensity under CO{sub 2} pressure which may be described by the Henry or Langmuir sorption models, while the positron response of other polymers is rather insensitive to the CO{sub 2} pressure. The results demonstrate the usefulness of positron annihilation spectroscopy in investigating the sorption of CO{sub 2} into various polymers at pressures up to about 3 atm (45psi).

  17. Measurement of the average {ital B} hadron lifetime in {ital Z}° decays using reconstructed vertices

    Microsoft Academic Search

    K. Abe; I. Abt; C. J. Ahn; T. Akagi; N. J. Allen; W. W. Ash; D. Aston; K. G. Baird; C. Baltay; H. R. Band; M. B. Barakat; G. Baranko; O. Bardon; T. Barklow; A. O. Bazarko; R. Ben-David; A. C. Benvenuti; G. M. Bilei; D. Bisello; G. Blaylock; J. R. Bogart; T. Bolton; G. R. Bower; J. E. Brau; M. Breidenbach; W. M. Bugg; D. Burke; T. H. Burnett; P. N. Burrows; W. Busza; A. Calcaterra; D. O. Caldwell; D. Calloway; B. Camanzi; M. Carpinelli; R. Cassell; R. Castaldi; A. Castro; M. Cavalli-Sforza; E. Church; H. O. Cohn; J. A. Coller; V. Cook; R. Cotton; R. F. Cowan; D. G. Coyne; C. J. S. Damerell; M. Daoudi; R. De Sangro; P. De Simone; M. Dima; P. Y. C. Du; R. Dubois; B. I. Eisenstein; R. Elia; D. Falciai; C. Fan; M. J. Fero; R. Frey; K. Furuno; T. Gillman; G. Gladding; S. Gonzalez; G. D. Hallewell; E. L. Hart; Y. Hasegawa; S. Hedges; S. S. Hertzbach; M. D. Hildreth; J. Huber; M. E. Huffer; E. W. Hughes; H. Hwang; Y. Iwasaki; D. J. Jackson; P. Jacques; J. Jaros; A. S. Johnson; J. R. Johnson; R. A. Johnson; T. Junk; R. Kajikawa; M. Kalelkar; H. J. Kang; I. Karliner; H. Kawahara; H. W. Kendall; Y. Kim; M. E. King; R. King; R. R. Kofler; N. M. Krishna; R. S. Kroeger; J. F. Labs; M. Langston; A. Lath; J. A. Lauber; D. W. G. S. Leith; M. X. Liu; X. Liu; M. Loreti; A. Lu; H. L. Lynch; J. Ma; G. Mancinelli; S. Manly; G. Mantovani; T. W. Markiewicz; T. Maruyama; R. Massetti; H. Masuda; E. Mazzucato; A. K. McKemey; B. T. Meadows; R. Messner; P. M. Mockett; K. C. Moffeit; B. Mours; G. Mueller; D. Muller; T. Nagamine; U. Nauenberg; H. Neal; M. Nussbaum; Y. Ohnishi; L. S. Osborne; R. S. Panvini; T. J. Pavel; I. Peruzzi; M. Piccolo; L. Piemontese; E. Pieroni; K. T. Pitts; R. J. Plano; R. Prepost; C. Y. Prescott; G. D. Punkar; J. Quigley; B. N. Ratcliff; T. W. Reeves; J. Reidy; P. E. Rensing; L. S. Rochester; J. E. Rothberg; P. C. Rowson; J. J. Russell

    1995-01-01

    We report a measurement of the average {ital B} hadron lifetime using data collected with the SLD detector at the SLAC Linear Collider in 1993. An inclusive analysis selected three-dimensional vertices with {ital B} hadron lifetime information in a sample of 50Ã10³ {ital Z}° decays. A lifetime of 1.564±0.030(stat)±0.036(syst) ps was extracted from the decay length distribution of these vertices

  18. Fracture aperture evolution during carbonate dissolution measured using positron emission projection imaging.

    NASA Astrophysics Data System (ADS)

    Ellis, P.; Greswell, R.; Riley, M.; Isakov, E.; Parker, D.

    2003-04-01

    Fracture flow (and fracture aperture) is of primary importance in hydrogeological studies and fracture development as a result of dissolution is significant in geological environments such as Karstic aquifers. The development of the fracture aperture is dependent on coupled flow and dissolution/precipitation processes that are difficult to investigate directly. We use Positron Emission Projection Imaging (PEPI) to quantify the evolution of fracture aperture during the dissolution of a carbonate rock under laminar flow conditions. Acidified water is passed through an initially smooth walled fracture between two limestone blocks and the levels of Ca, ppCO_2, pH and temperature are monitored continuously. At regular intervals the fracture aperture is measured using PEPI. Data from the experiment provides input to a numerical model that is used to investigate the relationship between the changing aperture distribution, flow and dissolution rates and the mineralogy of the fracture surface. Positron Emission Projection Imaging (PEPI) has been developed at the University of Birmingham for the study of solute and particle transport in aquifer forming rocks. The technique has been adapted from Positron Emission Tomography (PET) used predominantly for medical investigations. Positrons emitted from a suitable tracer collide with electrons within the sample which results in annihilation of both particles and the emission of two co-linear gamma rays. Detectors enable the distribution of the tracer to be calculated from the observation of many annihilation events. Using PEPI it is possible to observe the transport of tracers within a rock in time and space. In the case of a fracture, the aperture distribution can be measured, as, in the case of a uniformly concentrated solution, the activity is proportional to the aperture. Advantages of PEPI over other non-invasive methods such as nuclear magnetic resonance imaging (NMRI) include a large field of view (30 x 30 cm), greater resolution of aperture and rapid imaging time (as little as 1 minute). This paper presents the initial results from experiments to examine the evolution of aperture within a block of fractured limestone undergoing dissolution.

  19. Frequency domain measurements of the fluorescence lifetime of ribonuclease T1.

    PubMed Central

    Eftink, M R; Ghiron, C A

    1987-01-01

    Using multifrequency phase/modulation fluorometry, we have studied the fluorescence decay of the single tryptophan residue of ribonuclease T1 (RNase T1). At neutral pH (7.4) we find that the decay is a double exponential (tau 1 = 3.74 ns, tau 2 = 1.06 ns, f1 = 0.945), in agreement with results from pulsed fluorometry. At pH 5.5 the decay is well described by a single decay time (tau = 3.8 ns). Alternatively, we have fitted the frequency domain data by a distribution of lifetimes. Temperature dependence studies were performed. If analyzed via a double exponential model, the activation energy for the inverse of the short lifetime component (at pH 7.4) is found to be 3.6 kcal/mol, as compared with a value of 1.0 kcal/mol for the activation energy of the inverse of the long lifetime component. If analyzed via the distribution model, the width of the distribution is found to increase at higher temperature. We have also repeated, using lifetime measurements, the temperature dependence of the acrylamide quenching of the fluorescence of RNase T1 at pH 5.5. We find an activation energy of 8 kcal/mol for acrylamide quenching, in agreement with our earlier report. Images FIGURE 3 FIGURE 7 PMID:3115328

  20. Continued Analysis of the NIST Neutron Lifetime Measurement Using Ultracold Neutrons

    NASA Astrophysics Data System (ADS)

    Huffer, Craig; Huffman, P. R.; Schelhammer, K. W.; Dewey, M. S.; Huber, M. G.; Hughes, P. P.; Mumm, H. P.; Thompson, A. K.; Coakley, K.; Yue, A. T.; O'Shaughnessy, C. M.; Yang, L.

    2013-10-01

    The neutron lifetime is an important parameter for constraining the Standard Model and providing input for Big Bang Nucleosynthesis. The current disagreement in the most recent generation of lifetime experiments suggests unknown or underestimated systematics and motivates the need for alternative measurement methods as well as additional investigations into potential systematics. Our measurement was performed using magnetically trapped Ultracold Neutrons in a 3.1 T Ioffe type trap configuration. The decay rate of the neutron population is recorded in real time by monitoring visible light resulting from beta decay. Data collected in late 2010 and early 2011 is being analyzed and systematic effects are being investigated. An overview of our current work on the analysis, Monte Carlo simulations, and systematic effects will be provided. This work was supported by the NSF and NIST.

  1. A simulation tool for Recoil Distance Method lifetime measurements at NSCL

    NASA Astrophysics Data System (ADS)

    Adrich, P.; Enderich, D.; Miller, D.; Moeller, V.; Norris, R. P.; Starosta, K.; Vaman, C.; Voss, P.; Dewald, A.

    2009-01-01

    A detailed, universal simulation tool for the Recoil Distance Method lifetime measurements at the National Superconducting Cyclotron Laboratory (NSCL) is presented. The measurements are made with the Köln-NSCL plunger-SeGA setup and utilize fast, secondary beams of exotic nuclei provided by the Coupled Cyclotron Facility and the A1900 fragment separator. The simulation tool, built upon GEANT4 and Root toolkits, incorporates all relevant aspects of a plunger experiment. The tool is applied in two ways. First, to aid in the design of new experiments by facilitating the choice of optimal experimental conditions. Second, to aid in off-line analysis of the experimental data and in particular to deduce the lifetime by comparison of experimental and simulated peak shapes in the ?-ray energy spectra. All the important features of the simulation tool are described, followed by examples of the application of the tool in the cases of real experiments completed or proposed at NSCL.

  2. Lifetime measurement of the 5d$^2$D$_{5/2}$ state in Ba$^+$

    E-print Network

    Mohanty, Amita; Portela, Mayerlin Nuñez; Valappol, Nivedya; Grier, Andrew T; Meijknecht, Thomas; Willmann, Lorenz; Jungmann, Klaus

    2015-01-01

    The lifetime of the metastable 5d$^2$D$_{5/2}$ state has been measured for a single trapped Ba$^+$ ion in a Paul trap in Ultra High Vacuum (UHV) in the 10$^{-10}$ mbar pressure range. A total of 5046 individual periods when the ion was shelved in this state have been recorded. A preliminary value $\\tau_{D_{5/2}} = 26.4(1.7)$~s is obtained through extrapolation to zero residual gas pressure.

  3. Measurement of the effective $B_s\\\\rightarrow K^+K^-$ lifetime

    Microsoft Academic Search

    R. Aaij; C. Abellan Beteta; B. Adeva; M. Adinolfi; C. Adrover; A. Affolder; Z. Ajaltouni; J. Albrecht; F. Alessio; M. Alexander; G. Alkhazov; P. Alvarez Cartelle; A. A. Alves Jr; S. Amato; Y. Amhis; J. Anderson; R. B. Appleby; O. Aquines Gutierrez; F. Archilli; L. Arrabito; A. Artamonov; M. Artuso; E. Aslanides; G. Auriemma; S. Bachmann; J. J. Back; D. S. Bailey; V. Balagura; W. Baldini; R. J. Barlow; C. Barschel; S. Barsuk; W. Barter; A. Bates; C. Bauer; Th. Bauer; A. Bay; I. Bediaga; S. Belogurov; K. Belous; I. Belyaev; E. Ben-Haim; M. Benayoun; G. Bencivenni; S. Benson; J. Benton; R. Bernet; M.-O. Bettler; M. van Beuzekom; A. Bien; S. Bifani; A. Bizzeti; P. M. Bjørnstad; T. Blake; F. Blanc; C. Blanks; J. Blouw; S. Blusk; A. Bobrov; V. Bocci; A. Bondar; N. Bondar; W. Bonivento; S. Borghi; A. Borgia; T. J. V. Bowcock; C. Bozzi; T. Brambach; J. van den Brand; J. Bressieux; D. Brett; S. Brisbane; M. Britsch; T. Britton; N. H. Brook; H. Brown; A. Büchler-Germann; I. Burducea; A. Bursche; J. Buytaert; S. Cadeddu; J. M. Caicedo Carvajal; O. Callot; M. Calvi; M. Calvo Gomez; A. Camboni; P. Campana; A. Carbone; G. Carboni; R. Cardinale; A. Cardini; L. Carson; K. Carvalho Akiba; G. Casse; M. Cattaneo; M. Charles; Ph. Charpentier; N. Chiapolini; K. Ciba; X. Cid Vidal; G. Ciezarek; P. E. L. Clarke; M. Clemencic; H. V. Cliff; J. Closier; C. Coca; V. Coco; J. Cogan; P. Collins; A. Comerma-Montells; F. Constantin; G. Conti; A. Contu; A. Cook; M. Coombes; G. Corti; G. A. Cowan; R. Currie; B. D'Almagne; C. D'Ambrosio; P. David; I. De Bonis; S. De Capua; M. De Cian; F. De Lorenzi; J. M. De Miranda; L. De Paula; P. De Simone; D. Decamp; M. Deckenhoff; H. Degaudenzi; M. Deissenroth; L. Del Buono; C. Deplano; D. Derkach; O. Deschamps; F. Dettori; J. Dickens; H. Dijkstra; P. Diniz Batista; F. Domingo Bonal; S. Donleavy; F. Dordei; A. Dosil Suárez; D. Dossett; A. Dovbnya; F. Dupertuis; R. Dzhelyadin; A. Dziurda; S. Easo; U. Egede; V. Egorychev; S. Eidelman; D. van Eijk; F. Eisele; S. Eisenhardt; R. Ekelhof; L. Eklund; Ch. Elsasser; D. G. d'Enterria; D. Esperante Pereira; L. Estève; A. Falabella; E. Fanchini; C. Färber; G. Fardell; C. Farinelli; S. Farry; V. Fave; V. Fernandez Albor; M. Ferro-Luzzi; S. Filippov; C. Fitzpatrick; M. Fontana; F. Fontanelli; R. Forty; M. Frank; C. Frei; M. Frosini; S. Furcas; A. Gallas Torreira; D. Galli; M. Gandelman; P. Gandini; Y. Gao; J. C. Garnier; J. Garofoli; J. Garra Tico; L. Garrido; D. Gascon; C. Gaspar; N. Gauvin; M. Gersabeck; T. Gershon; Ph. Ghez; V. Gibson; V. V. Gligorov; C. Göbel; D. Golubkov; A. Golutvin; A. Gomes; H. Gordon; M. Grabalosa Gándara; R. Graciani Diaz; L. A. Granado Cardoso; E. Graugés; G. Graziani; A. Grecu; E. Greening; S. Gregson; B. Gui; E. Gushchin; Yu. Guz; T. Gys; G. Haefeli; C. Haen; S. C. Haines; T. Hampson; S. Hansmann-Menzemer; R. Harji; N. Harnew; J. Harrison; P. F. Harrison; J. He; V. Heijne; K. Hennessy; P. Henrard; J. A. Hernando Morata; E. van Herwijnen; E. Hicks; K. Holubyev; P. Hopchev; W. Hulsbergen; P. Hunt; T. Huse; R. S. Huston; D. Hutchcroft; D. Hynds; V. Iakovenko; P. Ilten; J. Imong; R. Jacobsson; A. Jaeger; M. Jahjah Hussein; E. Jans; F. Jansen; P. Jaton; B. Jean-Marie; F. Jing; M. John; D. Johnson; C. R. Jones; B. Jost; M. Kaballo; S. Kandybei; M. Karacson; T. M. Karbach; J. Keaveney; U. Kerzel; T. Ketel; A. Keune; B. Khanji; Y. M. Kim; M. Knecht; S. Koblitz; P. Koppenburg; A. Kozlinskiy; L. Kravchuk; K. Kreplin; M. Kreps; G. Krocker; P. Krokovny; F. Kruse; K. Kruzelecki; M. Kucharczyk; R. Kumar; T. Kvaratskheliya; V. N. La Thi; D. Lacarrere; G. Lafferty; A. Lai; D. Lambert; R. W. Lambert; E. Lanciotti; G. Lanfranchi; C. Langenbruch; T. Latham; R. Le Gac; J. van Leerdam; J.-P. Lees; R. Lefévre; A. Leflat; J. Lefrançois; O. Leroy; T. Lesiak; L. Li; L. Li Gioi; M. Lieng; M. Liles; R. Lindner; C. Linn; B. Liu; G. Liu; J. H. Lopes; E. Lopez Asamar; N. Lopez-March; J. Luisier; F. Machefert; I. V. Machikhiliyan; F. Maciuc; O. Maev; J. Magnin; S. Malde; R. M. D. Mamunur; G. Manca; G. Mancinelli; N. Mangiafave; U. Marconi; R. Märki; J. Marks; G. Martellotti; A. Martens; L. Martin; A. Martín Sánchez; D. Martinez Santos; A. Massafferri; Z. Mathe; C. Matteuzzi; M. Matveev; E. Maurice; B. Maynard; A. Mazurov; G. McGregor; R. McNulty; C. Mclean; M. Meissner; M. Merk; J. Merkel; R. Messi; S. Miglioranzi; D. A. Milanes; M.-N. Minard; S. Monteil; D. Moran; P. Morawski; I. Mous; F. Muheim; K. Müller; R. Muresan; B. Muryn; M. Musy; J. Mylroie-Smith; P. Naik; T. Nakada; R. Nandakumar; J. Nardulli; I. Nasteva; M. Nedos; M. Needham; N. Neufeld; C. Nguyen-Mau; M. Nicol; S. Nies; V. Niess; N. Nikitin; A. Nomerotski; A. Novoselov; A. Oblakowska-Mucha; V. Obraztsov; S. Oggero; S. Ogilvy; O. Okhrimenko; R. Oldeman; M. Orlandea; J. M. Otalora Goicochea; P. Owen; K. Pal; J. Palacios; A. Palano; M. Palutan

    2011-01-01

    A measurement of the effective $B_s\\\\rightarrow K^+K^-$ lifetime is presented using approximately $37 pb^{-1}$ of data collected by LHCb during 2010. This quantity can be used to put constraints on contributions from processes beyond the Standard Model in the $B_s$ meson system and is determined by two complementary approaches as $\\\\tau_{B_s\\\\to K^+K^-} = 1.440 \\\\pm 0.096 (stat) \\\\pm 0.008 (syst)

  4. Measurement of the Lambda0b Lifetime Using Lambda0b-->Lambda+cl-nu¯

    Microsoft Academic Search

    F. Abe; H. Akimoto; A. Akopian; M. G. Albrow; S. R. Amendolia; D. Amidei; J. Antos; C. Anway-Wiese; S. Aota; G. Apollinari; T. Asakawa; W. Ashmanskas; M. Atac; F. Azfar; P. Azzi-Bacchetta; N. Bacchetta; W. Badgett; S. Bagdasarov; M. W. Bailey; J. Bao; P. de Barbaro; A. Barbaro-Galtieri; V. E. Barnes; B. A. Barnett; E. Barzi; G. Bauer; T. Baumann; F. Bedeschi; S. Behrends; S. Belforte; G. Bellettini; J. Bellinger; D. Benjamin; J. Benlloch; J. Bensinger; D. Benton; A. Beretvas; J. P. Berge; J. Berryhill; S. Bertolucci; A. Bhatti; K. Biery; M. Binkley; D. Bisello; R. E. Blair; C. Blocker; A. Bodek; W. Bokhari; V. Bolognesi; D. Bortoletto; J. Boudreau; L. Breccia; C. Bromberg; N. Bruner; E. Buckley-Geer; H. S. Budd; K. Burkett; G. Busetto; A. Byon-Wagner; K. L. Byrum; J. Cammerata; C. Campagnari; M. Campbell; A. Caner; W. Carithers; D. Carlsmith; A. Castro; D. Cauz; Y. Cen; F. Cervelli; P. S. Chang; P. T. Chang; H. Y. Chao; J. Chapman; M.-T. Cheng; G. Chiarelli; T. Chikamatsu; C. N. Chiou; L. Christofek; S. Cihangir; A. G. Clark; M. Cobal; M. Contreras; J. Conway; J. Cooper; M. Cordelli; C. Couyoumtzelis; D. Crane; D. Cronin-Hennessy; R. Culbertson; J. D. Cunningham; T. Daniels; F. Dejongh; S. Delchamps; S. dell'Agnello; M. dell'Orso; R. Demina; L. Demortier; B. Denby; M. Deninno; P. F. Derwent; T. Devlin; J. R. Dittmann; S. Donati; J. Done; T. Dorigo; A. Dunn; N. Eddy; K. Einsweiler; J. E. Elias; R. Ely; E. Engels Jr.; D. Errede; S. Errede; Q. Fan; I. Fiori; B. Flaugher; G. W. Foster; M. Franklin; M. Frautschi; J. Freeman; J. Friedman; T. A. Fuess; Y. Fukui; S. Funaki; G. Gagliardi; S. Galeotti; M. Gallinaro; M. Garcia-Sciveres; A. F. Garfinkel; C. Gay; S. Geer; D. W. Gerdes; P. Giannetti; N. Giokaris; P. Giromini; L. Gladney; D. Glenzinski; M. Gold; J. Gonzalez; A. Gordon; A. T. Goshaw; K. Goulianos; H. Grassmann; L. Groer; C. Grosso-Pilcher; G. Guillian; R. S. Guo; C. Haber; E. Hafen; S. R. Hahn; R. Handler; R. M. Hans; K. Hara; A. D. Hardman; B. Harral; R. M. Harris; S. A. Hauger; J. Hauser; C. Hawk; E. Hayashi; J. Heinrich; K. D. Hoffman; M. Hohlmann; C. Holck; R. Hollebeek; L. Holloway; A. Hölscher; S. Hong; G. Houk; P. Hu; B. T. Huffman; R. Hughes; J. Huston; J. Huth; J. Hylen; H. Ikeda; M. Incagli; J. Incandela; G. Introzzi; J. Iwai; Y. Iwata; H. Jensen; U. Joshi; R. W. Kadel; E. Kajfasz; H. Kambara; T. Kamon; T. Kaneko; K. Karr; H. Kasha; Y. Kato; T. A. Keaffaber; L. Keeble; K. Kelley; R. D. Kennedy; R. Kephart; P. Kesten; D. Kestenbaum; R. M. Keup; H. Keutelian; F. Keyvan; B. Kharadia; B. J. Kim; D. H. Kim; H. S. Kim; S. B. Kim; S. H. Kim; Y. K. Kim; L. Kirsch; P. Koehn; K. Kondo; J. Konigsberg; S. Kopp; K. Kordas; W. Koska; E. Kovacs; W. Kowald; M. Krasberg; J. Kroll; M. Kruse; T. Kuwabara; S. E. Kuhlmann; E. Kuns; A. T. Laasanen; N. Labanca; S. Lammel; J. I. Lamoureux; T. Lecompte; S. Leone; J. D. Lewis; P. Limon; M. Lindgren; T. M. Liss; N. Lockyer; O. Long; C. Loomis; M. Loreti; J. Lu; D. Lucchesi; P. Lukens; S. Lusin; J. Lys; K. Maeshima; A. Maghakian; P. Maksimovic; M. Mangano; J. Mansour; M. Mariotti; J. P. Marriner; A. Martin; J. A. Matthews; R. Mattingly; P. McIntyre; P. Melese; A. Menzione; E. Meschi; S. Metzler; C. Miao; T. Miao; G. Michail; R. Miller; H. Minato; S. Miscetti; M. Mishina; H. Mitsushio; T. Miyamoto; S. Miyashita; N. Moggi; Y. Morita; J. Mueller; A. Mukherjee; T. Muller; P. Murat; H. Nakada; I. Nakano; C. Nelson; D. Neuberger; C. Newman-Holmes; M. Ninomiya; L. Nodulman; S. H. Oh; K. E. Ohl; T. Ohmoto; T. Ohsugi; R. Oishi; M. Okabe; T. Okusawa; R. Oliveira; J. Olsen; C. Pagliarone; R. Paoletti; V. Papadimitriou; S. P. Pappas; A. Parri; J. Patrick; G. Pauletta; M. Paulini; A. Perazzo; L. Pescara; M. D. Peters; T. J. Phillips; G. Piacentino; M. Pillai; K. T. Pitts; R. Plunkett; L. Pondrom; J. Proudfoot; F. Ptohos; G. Punzi; K. Ragan; A. Ribon; F. Rimondi; L. Ristori; W. J. Robertson; T. Rodrigo; S. Rolli; J. Romano; L. Rosenson; R. Roser; W. K. Sakumoto; D. Saltzberg; A. Sansoni; L. Santi; H. Sato; V. Scarpine; P. Schlabach; E. E. Schmidt; M. P. Schmidt; A. Scribano; S. Segler; S. Seidel; Y. Seiya; G. Sganos; M. Shapiro; N. M. Shaw; Q. Shen; P. F. Shepard; M. Shimojima; M. Shochet; J. Siegrist; A. Sill; P. Sinervo; P. Singh; J. Skarha; K. Sliwa; F. D. Snider; T. Song; J. Spalding; T. Speer; P. Sphicas; F. Spinella; M. Spiropulu; L. Spiegel; L. Stanco; J. Steele; A. Stefanini; K. Strahl; J. Strait; R. Ströhmer; D. Stuart; G. Sullivan; A. Soumarokov; K. Sumorok; J. Suzuki; T. Takada; T. Takahashi; T. Takano; K. Takikawa; N. Tamura; F. Tartarelli; W. Taylor; P. K. Teng; Y. Teramoto; S. Tether; D. Theriot; T. L. Thomas; R. Thun; M. Timko; P. Tipton; A. Titov; S. Tkaczyk; D. Toback; K. Tollefson; A. Tollestrup; J. Tonnison; J. F. de Troconiz; S. Truitt; J. Tseng; N. Turini; T. Uchida; N. Uemura; F. Ukegawa; G. Unal; S. van den Brink; S. Vejcik III; G. Velev; R. Vidal

    1996-01-01

    The lifetime of Lambda0b is measured using the semileptonic decay Lambda0b-->Lambda+cl-nu¯, where the Lambda+c is reconstructed through its decay Lambda+c-->pK-pi+. The data were collected by the CDF detector at the Tevatron Collider during 1992-1995 and correspond to an integrated luminosity of 110 pb-1 of pp¯ collisions at s = 1.8 TeV. From a fit to the decay length distribution of

  5. Nuclear structure studies of {sup 70}Zn from g-factor and lifetime measurements

    SciTech Connect

    Muecher, D. [Institut fuer Kernphysik, Universitaet zu Koeln, Zuelpicher Str. 77, D-50937 Koeln (Germany); Guerdal, G.; Kumbartzki, G. J.; Benczer-Koller, N.; Sharon, Y. Y.; Zamick, L.; Krieger, B. [Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854 (United States); Speidel, K.-H. [Helmholtz-Institut fuer Strahlen- und Kernphysik, Universitaet Bonn, Nussallee 14-16, D-53115 Bonn (Germany); Robinson, S. J. Q. [Physics Department, Millsaps College, Jackson, Mississippi 39210 (United States); Lisetskiy, A. F. [Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States); Casperson, R. J.; Heinz, A.; Werner, V.; Williams, E.; Winkler, R. [A. W. Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States); Leske, J. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgartenstr. 9, D-64289 Darmstadt (Germany); Maier-Komor, P. [Physik-Department, Technische Universitaet Muenchen, James-Franck-Str., D-85748 Garching (Germany)

    2009-05-15

    The g factors and mean lifetimes of several short-lived low-lying states in {sub 30}{sup 70}Zn{sub 40} have been measured using the techniques of projectile Coulomb excitation in inverse kinematics combined with transient magnetic fields and the Doppler-shift attenuation method. The present results have been interpreted within the framework of large-scale shell-model calculations that include the g{sub 9/2} orbital.

  6. Precise Measurement of B Meson Lifetimes with Hadronic Decay Final States

    Microsoft Academic Search

    K. Abe; R. Abe; T. Abe; I. Adachi; Byoung Sup Ahn; H. Aihara; M. Akatsu; Y. Asano; T. Aso; T. Aushev; A. M. Bakich; Y. Ban; E. Banas; S. Behari; P. K. Behera; A. Bondar; A. Bozek; J. Brodzicka; T. E. Browder; B. C. Casey; P. Chang; Y. Chao; B. G. Cheon; R. Chistov; S.-K. Choi; Y. Choi; L. Y. Dong; J. Dragic; A. Drutskoy; S. Eidelman; V. Eiges; Y. Enari; C. W. Everton; F. Fang; H. Fujii; C. Fukunaga; M. Fukushima; N. Gabyshev; A. Garmash; T. Gershon; A. Gordon; H. Guler; R. Guo; J. Haba; H. Hamasaki; K. Hanagaki; F. Handa; K. Hara; T. Hara; N. C. Hastings; H. Hayashii; M. Hazumi; E. M. Heenan; I. Higuchi; T. Higuchi; T. Hokuue; Y. Hoshi; S. R. Hou; W.-S. Hou; S.-C. Hsu; H.-C. Huang; T. Igaki; Y. Igarashi; T. Iijima; H. Ikeda; K. Inami; A. Ishikawa; H. Ishino; R. Itoh; H. Iwasaki; Y. Iwasaki; H. K. Jang; J. H. Kang; J. S. Kang; P. Kapusta; N. Katayama; H. Kawai; Y. Kawakami; N. Kawamura; T. Kawasaki; H. Kichimi; D. W. Kim; Heejong Kim; H. J. Kim; H. O. Kim; Hyunwoo Kim; S. K. Kim; T. H. Kim; K. Kinoshita; H. Konishi; S. Korpar; P. Krizan; P. Krokovny; R. Kulasiri; S. Kumar; A. Kuzmin; Y.-J. Kwon; J. S. Lange; S. H. Lee; A. Limosani; D. Liventsev; R.-S. Lu; J. MacNaughton; G. Majumder; F. Mandl; D. Marlow; T. Matsubara; T. Matsuishi; S. Matsumoto; T. Matsumoto; Y. Mikami; W. Mitaroff; K. Miyabayashi; Y. Miyabayashi; H. Miyake; H. Miyata; G. R. Moloney; S. Mori; T. Mori; T. Nagamine; Y. Nagasaka; Y. Nagashima; T. Nakadaira; E. Nakano; M. Nakao; J. W. Nam; Z. Natkaniec; K. Neichi; S. Nishida; O. Nitoh; S. Noguchi; T. Nozaki; S. Ogawa; F. Ohno; T. Ohshima; T. Okabe; S. Okuno; S. L. Olsen; W. Ostrowicz; H. Ozaki; P. Pakhlov; H. Palka; C. S. Park; C. W. Park; K. S. Park; L. S. Peak; J.-P. Perroud; M. Peters; L. E. Piilonen; J. L. Rodriguez; F. Ronga; M. Rozanska; K. Rybicki; H. Sagawa; Y. Sakai; M. Satapathy; A. Satpathy; O. Schneider; S. Schrenk; C. Schwanda; S. Semenov; K. Senyo; M. E. Sevior; H. Shibuya; B. Shwartz; V. Sidorov; J. B. Singh; S. Stanic; A. Sugi; A. Sugiyama; K. Sumisawa; T. Sumiyoshi; K. Suzuki; S. Suzuki; H. Tajima; T. Takahashi; F. Takasaki; M. Takita; K. Tamai; N. Tamura; J. Tanaka; M. Tanaka; G. N. Taylor; Y. Teramoto; S. Tokuda; M. Tomoto; T. Tomura; S. N. Tovey; K. Trabelsi; T. Tsuboyama; T. Tsukamoto; S. Uehara; K. Ueno; Y. Unno; S. Uno; Y. Ushiroda; K. E. Varvell; C. C. Wang; J. G. Wang; M.-Z. Wang; Y. Watanabe; E. Won; B. D. Yabsley; Y. Yamada; M. Yamaga; A. Yamaguchi; H. Yamamoto; Y. Yamashita; M. Yamauchi; S. Yanaka; J. Yashima; M. Yokoyama; Y. Yuan; Y. Yusa; C. C. Zhang; J. Zhang; Y. Zheng; V. Zhilich; D. Zontar

    2002-01-01

    The lifetimes of the Bbar0 and B- mesons are extracted from 29.1 fb-1 of data collected with the Belle detector at the KEK B factory. A fit to the decay length differences of neutral and charged B meson pairs, measured in events where one of the B mesons is fully reconstructed in several hadronic modes, yields tauBbar0 = 1.554+\\/-0.030(stat)+\\/-0.019(syst) ps,

  7. Measurement of the $B^-$ lifetime using a simulation free approach for trigger bias correction

    SciTech Connect

    Aaltonen, T.; /Helsinki Inst. of Phys.; Adelman, J.; /Chicago U., EFI; Alvarez Gonzalez, B.; /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U.; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Appel, J.; /Fermilab; Apresyan, A.; /Purdue U. /Waseda U.

    2010-04-01

    The collection of a large number of B hadron decays to hadronic final states at the CDF II detector is possible due to the presence of a trigger that selects events based on track impact parameters. However, the nature of the selection requirements of the trigger introduces a large bias in the observed proper decay time distribution. A lifetime measurement must correct for this bias and the conventional approach has been to use a Monte Carlo simulation. The leading sources of systematic uncertainty in the conventional approach are due to differences between the data and the Monte Carlo simulation. In this paper they present an analytic method for bias correction without using simulation, thereby removing any uncertainty between data and simulation. This method is presented in the form of a measurement of the lifetime of the B{sup -} using the mode B{sup -} {yields} D{sup 0}{pi}{sup -}. The B{sup -} lifetime is measured as {tau}{sub B{sup -}} = 1.663 {+-} 0.023 {+-} 0.015 ps, where the first uncertainty is statistical and the second systematic. This new method results in a smaller systematic uncertainty in comparison to methods that use simulation to correct for the trigger bias.

  8. Measurement of the B ? lifetime using a simulation free approach for trigger bias correction

    DOE PAGESBeta

    Aaltonen, T.; Adelman, J.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.; Apresyan, A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Attal, A.; Aurisano, A.; Azfar, F.; Badgett, W.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauer, G.; Beauchemin, P.-H.; Bedeschi, F.; Beecher, D.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Binkley, M.; Bisello, D.; Bizjak, I.; Blair, R. E.; Blocker, C.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Boisvert, V.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brau, B.; Bridgeman, A.; Brigliadori, L.; Bromberg, C.; Brubaker, E.; Budagov, J.; Budd, H. S.; Budd, S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Byrum, K. L.; Cabrera, S.; Calancha, C.; Camarda, S.; Campanelli, M.; Campbell, M.; Canelli, F.; Canepa, A.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chang, S. H.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chou, J. P.; Chung, K.; Chung, W. H.; Chung, Y. S.; Chwalek, T.; Ciobanu, C. I.; Ciocci, M. A.; Clark, A.; Clark, D.; Compostella, G.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Cuenca Almenar, C.; Cuevas, J.; Culbertson, R.; Cully, J. C.; Dagenhart, D.; d’Ascenzo, N.; Datta, M.; Davies, T.; de Barbaro, P.; De Cecco, S.; Deisher, A.; De Lorenzo, G.; Dell’Orso, M.; Deluca, C.; Demortier, L.; Deng, J.; Deninno, M.; d’Errico, M.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; D’Onofrio, M.; Donati, S.; Dong, P.; Dorigo, T.; Dube, S.; Ebina, K.; Elagin, A.; Erbacher, R.; Errede, D.; Errede, S.; Ershaidat, N.; Eusebi, R.; Fang, H. C.; Farrington, S.; Fedorko, W. T.; Feild, R. G.; Feindt, M.; Fernandez, J. P.; Ferrazza, C.; Field, R.; Flanagan, G.; Forrest, R.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Furic, I.; Gallinaro, M.; Galyardt, J.; Garberson, F.; Garcia, J. E.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerdes, D.; Gessler, A.; Giagu, S.; Giakoumopoulou, V.; Giannetti, P.; Gibson, K.; Gimmell, J. L.; Ginsburg, C. M.; Giokaris, N.; Giordani, M.; Giromini, P.; Giunta, M.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldschmidt, N.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gresele, A.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Grundler, U.; Guimaraes da Costa, J.; Gunay-Unalan, Z.; Haber, C.; Hahn, S. R.; Halkiadakis, E.; Han, B.-Y.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harr, R. F.; Hartz, M.; Hatakeyama, K.; Hays, C.; Heck, M.; Heinrich, J.; Herndon, M.; Heuser, J.; Hewamanage, S.; Hidas, D.; Hill, C. S.; Hirschbuehl, D.; Hocker, A.; Hou, S.; Houlden, M.; Hsu, S.-C.; Hughes, R. E.; Huffman, B. T.; Hurwitz, M.; Husemann, U.; Hussein, M.; Huston, J.; Incandela, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jha, M. K.; Jindariani, S.; Johnson, W.; Jones, M.; Joo, K. K.; Jun, S. Y.; Jung, J. E.; Junk, T. R.; Kamon, T.; Kar, D.; Karchin, P. E.; Kato, Y.; Kephart, R.; Ketchum, W.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, H. W.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kimura, N.; Kirsch, L.; Klimenko, S.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Korytov, A.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Krumnack, N.; Kruse, M.; Krutelyov, V.; Kuhr, T.; Kulkarni, N. P.; Kurata, M.; Kwang, S.; Laasanen, A. T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R. L.; Lannon, K.; Lath, A.; Latino, G.; Lazzizzera, I.; LeCompte, T.; Lee, E.; Lee, H. S.; Lee, J. S.; Lee, S. W.; Leone, S.; Lewis, J. D.; Lin, C.-J.; Linacre, J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, T.; Lockyer, N. S.; Loginov, A.; Lovas, L.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lyons, L.; Lys, J.; Lysak, R.; MacQueen, D.; Madrak, R.; Maeshima, K.; Makhoul, K.; Maksimovic, P.; Malde, S.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Marino, C. P.; Martin, A.; Martin, V.; Martínez, M.; Martínez-Ballarín, R.; Mastrandrea, P.; Mathis, M.; Mattson, M. E.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Menzione, A.; Mesropian, C.; Miao, T.; Mietlicki, D.; Miladinovic, N.; Miller, R.; Mills, C.; Milnik, M.; Mitra, A.; Mitselmakher, G.; Miyake, H.; Moed, S.; Moggi, N.; Mondragon, M. N.; Moon, C. S.; Moore, R.; Morello, M. J.; Morlock, J.; Movilla Fernandez, P.; Mülmenstädt, J.; Mukherjee, A.; Muller, Th.; Murat, P.

    2011-02-01

    The collection of a large number of B-hadron decays to hadronic final states at the CDF II Detector is possible due to the presence of a trigger that selects events based on track impact parameters. However, the nature of the selection requirements of the trigger introduces a large bias in the observed proper-decay-time distribution. A lifetime measurement must correct for this bias, and the conventional approach has been to use a Monte Carlo simulation. The leading sources of systematic uncertainty in the conventional approach are due to differences between the data and the Monte Carlo simulation. In this paper, we present an analytic method for bias correction without using simulation, thereby removing any uncertainty due to the differences between data and simulation. This method is presented in the form of a measurement of the lifetime of the B? using the mode B??D???. The B? lifetime is measured as ?B?=1.663±0.023±0.015 ps, where the first uncertainty is statistical and the second systematic. This new method results in a smaller systematic uncertainty in comparison to methods that use simulation to correct for the trigger bias.

  9. MEASUREMENTS OF NATURAL SELECTION ON FLORAL TRAITS IN WILD RADISH (RAPHANUS RAPHANISTRUM). I. SELECTION THROUGH LIFETIME FEMALE FITNESS

    Microsoft Academic Search

    JEFFREY K. CONNER; PETER JENNET; E. Healey

    Although the role of natural selection in the evolution of floral traits has been of great interest to biologists since Darwin, studies of selection on floral traits through differences in lifetime fitness have been rare. We measured selection acting on flower number, flower size, stigma exsertion, and ovule number per flower using field data on lifetime female fitness (seed production)

  10. Inclusive measurements of inelastic electron and positron scattering from unpolarized hydrogen and deuterium targets

    NASA Astrophysics Data System (ADS)

    Airapetian, A.; Akopov, N.; Akopov, Z.; Aschenauer, E. C.; Augustyniak, W.; Avakian, R.; Avetissian, A.; Avetisyan, E.; Belostotski, S.; Bianchi, N.; Blok, H. P.; Borissov, A.; Bowles, J.; Bryzgalov, V.; Burns, J.; Capiluppi, M.; Capitani, G. P.; Cisbani, E.; Ciullo, G.; Contalbrigo, M.; Dalpiaz, P. F.; Deconinck, W.; de Leo, R.; de Nardo, L.; de Sanctis, E.; Diefenthaler, M.; di Nezza, P.; Düren, M.; Ehrenfried, M.; Elbakian, G.; Ellinghaus, F.; Fabbri, R.; Fantoni, A.; Felawka, L.; Frullani, S.; Gabbert, D.; Gapienko, G.; Gapienko, V.; Garibaldi, F.; Gavrilov, G.; Gharibyan, V.; Giordano, F.; Gliske, S.; Golembiovskaya, M.; Hadjidakis, C.; Hartig, M.; Hasch, D.; Hill, G.; Hillenbrand, A.; Hoek, M.; Holler, Y.; Hristova, I.; Imazu, Y.; Ivanilov, A.; Jackson, H. E.; Jo, H. S.; Joosten, S.; Kaiser, R.; Karyan, G.; Keri, T.; Kinney, E.; Kisselev, A.; Korotkov, V.; Kozlov, V.; Kravchenko, P.; Krivokhijine, V. G.; Lagamba, L.; Lamb, R.; Lapikás, L.; Lehmann, I.; Lenisa, P.; Linden-Levy, L. A.; Ruiz, A. López; Lorenzon, W.; Lu, X.-G.; Lu, X.-R.; Ma, B.-Q.; Mahon, D.; Makins, N. C. R.; Manaenkov, S. I.; Manfré, L.; Mao, Y.; Marianski, B.; Martinez de La Ossa, A.; Marukyan, H.; Miller, C. A.; Miyachi, Y.; Movsisyan, A.; Muccifora, V.; Murray, M.; Mussgiller, A.; Nappi, E.; Naryshkin, Y.; Nass, A.; Negodaev, M.; Nowak, W.-D.; Pappalardo, L. L.; Perez-Benito, R.; Pickert, N.; Raithel, M.; Reimer, P. E.; Reolon, A. R.; Riedl, C.; Rith, K.; Rosner, G.; Rostomyan, A.; Rubin, J.; Ryckbosch, D.; Salomatin, Y.; Sanftl, F.; Schäfer, A.; Schnell, G.; Schüler, K. P.; Seitz, B.; Shibata, T.-A.; Shutov, V.; Stancari, M.; Statera, M.; Steffens, E.; Steijger, J. J. M.; Stenzel, H.; Stewart, J.; Stinzing, F.; Taroian, S.; Trzcinski, A.; Tytgat, M.; Vandenbroucke, A.; van Haarlem, Y.; van Hulse, C.; Veretennikov, D.; Vikhrov, V.; Vilardi, I.; Vogel, C.; Wang, S.; Yaschenko, S.; Ye, H.; Ye, Z.; Yen, S.; Yu, W.; Zeiler, D.; Zihlmann, B.; Zupranski, P.

    2011-05-01

    Results of inclusive measurements of inelastic electron and positron scattering from unpolarized protons and deuterons at the HERMES experiment are presented. The structure functions F 2 p and F 2 d are determined using a parameterization of existing data for the longitudinal-to-transverse virtual-photon absorption cross-section ratio. The HERMES results provide data in the ranges 0.006 ? x ? 0.9 and 0.1 GeV2 ? Q 2 ? 20 GeV2, covering the transition region between the perturbative and the non-perturbative regimes of QCD in a so-far largely unexplored kinematic region. They are in agreement with existing world data in the region of overlap. The measured cross sections are used, in combination with data from other experiments, to perform fits to the photon-nucleon cross section using the functional form of the ALLM model. The deuteron-to-proton cross-section ratio is also determined.

  11. Measurement of the {ital B}{sub {ital s}} meson lifetime

    SciTech Connect

    Abe, F.; Albrow, M.G.; Amendolia, S.R.; Amidei, D.; Antos, J.; Anway-Wiese, C.; Apollinari, G.; Areti, H.; Atac, M.; Auchincloss, P.; Azfar, F.; Azzi, P.; Bacchetta, N.; Badgett, W.; Bailey, M.W.; Bao, J.; de Barbaro, P.; Barbaro-Galtieri, A.; Barnes, V.E.; Barnett, B.A.; Bartalini, P.; Bauer, G.; Baumann, T.; Bedeschi, F.; Behrends, S.; Belforte, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Benlloch, J.; Bensinger, J.; Benton, D.; Beretvas, A.; Berge, J.P.; Bertolucci, S.; Bhatti, A.; Biery, K.; Binkley, M.; Bird, F.; Bisello, D.; Blair, R.E.; Blocker, C.; Bodek, A.; Bokhari, W.; Bolognesi, V.; Bortoletto, D.; Boswell, C.; Boulos, T.; Brandenburg, G.; Bromberg, C.; Buckley-Geer, E.; Budd, H.S.; Burkett, K.; Busetto, G.; Byon-Wagner, A.; Byrum, K.L.; Cammerata, J.; Campagnari, C.; Campbell, M.; Caner, A.; Carithers, W.; Carlsmith, D.; Castro, A.; Cen, Y.; Cervelli, F.; Chao, H.Y.; Chapman, J.; Cheng, M.; Chiarelli, G.; Chikamatsu, T.; Chiou, C.N.; Cihangir, S.; Clark, A.G.; Cobal, M.; Contreras, M.; Conway, J.; Cooper, J.; Cordelli, M.; Couyoumtzelis, C.; Crane, D.; Cunningham, J.D.; Daniels, T.; DeJongh, F.; Delchamps, S.; Dell`Agnello, S.; Dell`Orso, M.; Demortier, L.; Denby, B.; Deninno, M.; Derwent, P.F.; Devlin, T.; Dickson, M.; Dittmann, J.R.; Donati, S.; Drucker, R.B.; Dunn, A.; Einsweiler, K.; Elias, J.E.; Ely, R.; Engels, E. Jr.; Eno, S.; Errede, D.; Errede, S.; Fan, Q.; Farhat, B.; Fiori, I.; Flaugher, B.; Foster, G.W.; Franklin, M.; Frautschi, M.; Freeman, J.; Friedman, J.; Fry, A.; Fuess, T.A.; Fukui, Y.; Funaki, S.; Gagliardi, G.; Galeotti, S.; Gallinaro, M.; Garfinkel, A.F.; Geer, S.; Gerdes, D.W.; Giannetti, P.; Giokaris, N.; Giromini, P.; Gladney, L.; Glenzinski, D.; Gold, M.; Gonzalez, J.; Gordon, A.; Goshaw, A.T.; Goulianos, K.; Grassmann, H.; Grewal, A.; Grieco, G.; Groer, L.; Grosso-Pilcher, C.; Haber, C.; Hahn, S.R.; Hamilton, R.; Handler, R.; Hans, R.M.; Hara, K.; Harral, B.; Harris, R.M.; Hauger, S.A.; Hauser, J.; Hawk, C.; (CDF Collabo..

    1995-06-19

    The lifetime of the {ital B}{sub {ital s}} meson is measured using the semileptonic decay {ital B}{sub {ital s}}{r_arrow}{ital D}{sub {ital s}}{sup {minus}}l{sup +}{nu}{ital X}. The data sample consists of 19.3 pb{sup {minus}1} of {ital p{bar p}} collisions at {radical}{ital s}=1.8 TeV collected by the Collider Detector at Fermilab during 1992--1993. There are 76{plus_minus}8 l{sup +}{ital D}{sub {ital s}}{sup {minus}} signal events where the {ital D}{sub {ital s}} is identified via the decay {ital D}{sub {ital s}}{sup {minus}}{r_arrow}{phi}{pi}{sup {minus}}, {phi}{r_arrow}{ital K}{sup +}{ital K}{sup {minus}}. Using these events, the {ital B}{sub {ital s}} meson lifetime is determined to be {tau}{sub {ital s}}=1.42{sub {minus}0.23}{sup +0.27}(stat){plus_minus}0.11(syst) ps. A measurement of the {ital B}{sub {ital s}} lifetime in a low statistics sample of exclusive {ital B}{sub {ital s}}{r_arrow}{ital J}/{psi}{phi} decays is also presented in this paper.

  12. LIFETIME MEASUREMENT WITH PSEUDO MOVEABLE SEPTUM IN NSLS X-RAY RING

    SciTech Connect

    Wang, G.M.; Choi; J.; Kramer; S.; Shaftan; T.; Heese; R.; Yang; X.

    2011-03-28

    The National Synchrotron Light Source II (NSLS-II) is a state of the art 3 GeV third generation light source currently under construction at Brookhaven National Laboratory and starts to commission in 2014. The beam injection works with two septa and four fast kicker magnets in an injection section. To improve the injection stability and reproducibility, we plan to implement a slow local bump on top of the fast bump so that the fast kicker strength is reduced. This bump works as a pseudo movable septum. We can also use this 'movable' septum to measure the storage ring beam partial lifetime resulting from the septum edge and possibly increasing the lifetime by moving the stored beam orbit away from the edge. We demonstrate the feasibility of this idea, by implementing DC bump in NSLS X-ray ring. We report the results of beam lifetime measurements as a function of the amplitude of this bumped orbit relative to the septum and the idea of a slow bump that could reduce the fast bump magnet strengths.

  13. MuLan; a precision measurement of the muon lifetime and determination of the Fermi constant

    NASA Astrophysics Data System (ADS)

    Gorringe, Tim

    2007-10-01

    The Fermi constant GF determines the rates of weak processes that range from nuclear beta-decay to stellar nucleo-synthesis. At Paul Scherrer Institute, the MuLan experiment is seeking to determine the Fermi Constant by measuring the positive muon lifetime to an unprecedented precision of about one part-per-million - a twenty-fold improvement over earlier experimental efforts. The experiment uses an intense, pulsed, muon beam and a finely-segmented, fast-timing, scintillator array to record the decays of more than 10^12 muons. In this talk we report the results for the positive muon lifetime from our 2004 production run, and describe our progress to reaching the final goal of one ppm. The implications - both as a determination of a fundamental constant of the electroweak interaction and for the precision testing of the standard model - are also discussed.

  14. First ?K atom lifetime measurement and recent results from the DIRAC experiment

    NASA Astrophysics Data System (ADS)

    Zhabitsky, Mikhail

    2014-11-01

    We report evidence for ?K atoms production, using 24 GeV/c proton beam from CERN PS interacting with a thin Ni target. We have identified (178 ± 49) ?K pairs, which were produced in a bound state — ?K atom, which was subsequently broken-up (ionized) in the Ni target. Our analysis yields a first measurement of the ?K atom lifetime (2.5-1.8+3.0) fs [1]. This lifetime is connected in a model-independent way to the S-wave isospin-odd ?K scattering length |a0-| = 1/3|a1/2 - a3/2| = (0.11-0.04+0.09) M?-1 (aI for isospin I).

  15. Direct measurement of the radiative lifetime of vibrationally excited OH radicals.

    PubMed

    van de Meerakker, Sebastiaan Y T; Vanhaecke, Nicolas; van der Loo, Mark P J; Groenenboom, Gerrit C; Meijer, Gerard

    2005-07-01

    Neutral molecules, isolated in the gas phase, can be prepared in a long-lived excited state and stored in a trap. The long observation time afforded by the trap can then be exploited to measure the radiative lifetime of this state by monitoring the temporal decay of the population in the trap. This method is demonstrated here and used to benchmark the Einstein A coefficients in the Meinel system of OH. A pulsed beam of vibrationally excited OH radicals is Stark decelerated and loaded into an electrostatic quadrupole trap. The radiative lifetime of the upper Lamda-doublet component of the Chi2Pi3/2, v=1, J=3/2 level is determined as 59.0+/-2.0 ms, in good agreement with the calculated value of 58.0+/-1.0 ms. PMID:16090612

  16. Direct Measurement of the Radiative Lifetime of Vibrationally Excited OH Radicals

    NASA Astrophysics Data System (ADS)

    van de Meerakker, Sebastiaan Y.; Vanhaecke, Nicolas; van der Loo, Mark P.; Groenenboom, Gerrit C.; Meijer, Gerard

    2005-07-01

    Neutral molecules, isolated in the gas phase, can be prepared in a long-lived excited state and stored in a trap. The long observation time afforded by the trap can then be exploited to measure the radiative lifetime of this state by monitoring the temporal decay of the population in the trap. This method is demonstrated here and used to benchmark the Einstein A coefficients in the Meinel system of OH. A pulsed beam of vibrationally excited OH radicals is Stark decelerated and loaded into an electrostatic quadrupole trap. The radiative lifetime of the upper ?-doublet component of the X 2?3/2, v=1, J=3/2 level is determined as 59.0±2.0 ms, in good agreement with the calculated value of 58.0±1.0 ms.

  17. Fluorescence-lifetime determination in tissues or other scattering media from measurement of excitation and emission kinetics

    NASA Astrophysics Data System (ADS)

    Hutchinson, Christina L.; Troy, Tamara L.; Sevick-Muraca, Eva M.

    1996-05-01

    Measurements of nanosecond and subnanosecond fluorescence lifetimes are restricted to dilute, nonscattering systems since excitation and emission photon times of flight significantly affect measured fluorescent decay kinetics. We provide the theoretical rationale for frequency-domain measurements of phase-shift and amplitude demodulation made at excitation and emission wavelengths for direct determination of lifetimes in tissues and other scattering media. We confirm our analytical expressions using standard laser dyes such as 3,3`-diethylthiatricarbocyanine iodide, IR-125, and IR-140 in polystyrene suspensions with similar scattering properties as tissues. Our results have significant implication for lifetime-based spectroscopy in tissues and other scattering media.

  18. Measurement of the B-cmeson lifetime in the decay B-c?J/???

    SciTech Connect

    Aaltonen, T.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bisello, D.; Bizjak, I.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Calamba, A.; Calancha, C.; Camarda, S.; Campanelli, M.; Campbell, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chung, W. H.; Chung, Y. S.; Ciocci, M. A.; Clark, A.; Clarke, C.; Compostella, G.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Cuevas, J.; Culbertson, R.; Dagenhart, D.; d’Ascenzo, N.; Datta, M.; de Barbaro, P.; Dell’Orso, M.; Demortier, L.; Deninno, M.; Devoto, F.; d’Errico, M.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; D’Onofrio, M.; Donati, S.; Dong, P.; Dorigo, M.; Dorigo, T.; Ebina, K.; Elagin, A.; Eppig, A.; Erbacher, R.; Errede, S.; Ershaidat, N.; Eusebi, R.; Farrington, S.; Feindt, M.; Fernandez, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Funakoshi, Y.; Furic, I.; Gallinaro, M.; Garcia, J. E.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Giannetti, P.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Goldschmidt, N.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Halkiadakis, E.; Hamaguchi, A.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harr, R. F.; Hatakeyama, K.; Hays, C.; Heck, M.; Heinrich, J.; Herndon, M.; Hewamanage, S.; Hocker, A.; Hopkins, W.; Horn, D.; Hou, S.; Hughes, R. E.; Hurwitz, M.; Husemann, U.; Hussain, N.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kim, Y. J.; Kimura, N.; Kirby, M.; Klimenko, S.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Kruse, M.; Krutelyov, V.; Kuhr, T.; Kurata, M.; Kwang, S.; Laasanen, A. T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R. L.; Lannon, K.; Lath, A.; Latino, G.; LeCompte, T.; Lee, E.; Lee, H. S.; Lee, J. S.; Lee, S. W.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lin, C.-J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maeshima, K.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Martínez, M.; Mastrandrea, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Mondragon, M. N.; Moon, C. S.; Moore, R.; Morello, M. J.; Morlock, J.; Movilla Fernandez, P.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Neubauer, M. S.; Nielsen, J.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagan Griso, S.; Pagliarone, C.; Palencia, E.; Papadimitriou, V.; Paramonov, A. A.; Patrick, J.; Pauletta, G.; Paulini, M.; Paus, C.; Pellett, D. E.; Penzo, A.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Prokoshin, F.; Pranko, A.; Ptohos, F.; Punzi, G.; Rahaman, A.; Ramakrishnan, V.; Ranjan, N.; Redondo, I.; Renton, P.; Rescigno, M.; Riddick, T.; Rimondi, F.; Ristori, L.; Robson, A.; Rodrigo, T.; Rodriguez, T.; Rogers, E.; Rolli, S.; Roser, R.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Safonov, A.; Sakumoto, W. K.

    2013-01-01

    The lifetime of the B-c meson is measured using 272 exclusive B-c?J/?(?????)?? decays reconstructed in data from proton-antiproton collisions corresponding to an integrated luminosity of 6.7 fb?¹ recorded by the CDF II detector at the Fermilab Tevatron. The lifetime of the B-cmeson is measured to be ?(B-c)=0.452±0.048(stat)±0.027(syst) ps. This is the first measurement of the B-c meson lifetime in a fully reconstructed hadronic channel, and it agrees with previous results and has comparable precision.

  19. Gamma radiation production using channeled positron annihilation in crystals

    NASA Astrophysics Data System (ADS)

    Gevorkyan, A. S.; Oganesyan, Koryun B.; Rostovtsev, Yuri V.; Kurizki, Gershon

    2015-07-01

    The possibility of channeling low-energy relativistic positrons in some ionic crystals with axial symmetry is shown. The annihilation processes of positrons with medium electrons are investigated in detail. The lifetime of a positron in the regime of channeling is estimated; the existence of a long relaxation lifetime has been shown.

  20. Measurements of the masses, lifetimes and decay modes of hadrons at Tevatron

    SciTech Connect

    Dorigo, Mirco; /Trieste U. /INFN, Trieste

    2010-05-01

    The Tevatron provides 1.96 TeV p{bar p} collisions and allows for collection of rich b-hadron samples to the two experiments CDF and D0. The study of heavy flavor properties represents a fruitful opportunity to investigate the flavor sector of the Standard Model (SM) and to look for hints of New Physics (NP). Here we report the first measurement of polarization amplitudes in B{sub s}{sup 0} charmless decays, world leading results on b-hadron lifetimes, and measurements of several other properties of b-hadrons.

  1. Measurement of the lifetime of B-hadrons and a determination of Vcb

    Microsoft Academic Search

    B. Adeva; O. Adriani; M. Aguilar-Benitez; H. Akbari; J. Alcaraz; A. Aloisio; G. Alverson; M. G. Alviggi; G. Ambrosi; Q. An; H. Anderhub; A. L. Anderson; V. P. Andreev; T. Angelov; L. Antonov; D. Antreasyan; P. Arce; A. Arefiev; T. Azemoon; P. V. K. S. Baba; P. Bagnaia; J. A. Bakken; L. Baksay; R. C. Ball; S. Banerjee; J. Bao; R. Barillère; L. Barone; R. Battiston; A. Bay; U. Becker; F. Behner; J. Behrens; S. Beingessner; Gy. L. Bencze; J. Berdugo; P. Berges; B. Bertucci; A. Biland; G. M. Bilei; R. Bizzarri; J. J. Blaising; P. Blömeke; B. Blumenfeld; G. J. Bobbink; M. Bocciolini; R. Bock; A. Böhm; B. Borgia; D. Bourilkov; M. Bourquin; D. Boutigny; B. Bouwens; E. Brambilla; J. G. Branson; I. C. Brock; F. Bruyant; C. Buisson; A T Bujak; J. D. Burger; J. P. Burq; J K Busenitz; X. D. Cai; M. Capell; M. Caria; G. Carlino; F. Carminati; A. M. Cartacci; M. Cerrada; F. Cesaroni; Y. H. Chang; U. K. Chaturvedi; M. Chemarin; A. Chen; C. Chen; G. M. Chen; H. F. Chen; H. S. Chen; M. Chen; W. Y. Chen; G. Chiefari; C. Y. Chien; M. Chmeissani; C. Civinini; I. Clare; R. Clare; H. O. Cohn; G. Coignet; N. Colino; V. Commichau; G. Conforto; A. Contin; F. Crijns; X. Y. Cui; T. S. Dai; R. D'Allessandro; R D'Alessandro; A. Degré; K. Deiters; E. Dénes; P. Denes; F. Denotaristefani; M. Dhina; D. Dibitonto; M. Diemoz; H. R. Dimitrov; C. Dionisi; M. T. Dova; E. Drago; T. Driever; D. Duchesneau; P. Duinker; I. Duran; H. El Mamouni; A. Engler; F. J. Eppling; P. Extermann; R. Fabbretti; M. Fabre; S. Falciano; Q. Fan; S. J. Fan; O. Fackler; J. Fay; T. Ferguson; G. Fernandez; F. Ferroni; H. Fesefeldt; E. Fiandrini; J. Field; F. Filthaut; G. Finocchiaro; P. H. Fisher; G. Forconi; T. Foreman; K. Freudenreich; W. Friebel; M. Fukushima; M. Gailloud; Yu. Galaktionov; E. Gallo; S. N. Ganguli; P. Garcia-Abia; S. S. Gau; D. Gele; S. Gentile; M. Glaubman; S. Goldfarb; Z. F. Gong; E. Gonzalez; A. Gordeev; P. Göttlicher; D. Goujon; G. Gratta; C. Grinnell; M. Gruenewald; M. Guanziroli; J. K. Guo; A. Gurtu; H. R. Gustafson; L. J. Gutay; H. Haan; A. Hasan; D. Hauschildt; C. F. He; T. Hebbeker; M. Hebert; G. Herten; U. Herten; A. Hervé; K. Hilgers; H. Hofer; H. Hoorani; L. S. Hsu; G. Hu; B. Ille; M. M. Ilyas; V. Innocente; H. Janssen; S. Jezequel; B. N. Jin; L. W. Jones; A. Kasser; R. A. Khan; Yu. Kamyshkov; Y. Karyotakis; M. Kaur; S. Khokhar; V. Khoze; M. N. Kienzle-Focacci; W. Kinnison; D. Kirkby; A. Klimentov; O. Kornadt; V. Koutsenko; R. W. Kraemer; T. Kramer; V. R. Krastev; W. Krenz; J. Krizmanic; K. S. Kumar; V. Kumar; A. Kunin; V. Lalieu; G. Landi; K. Lanius; D. Lanske; S. Lanzano; P. Lebrun; P. Lecomte; P Lecomte; P. Le Coultre; D. Lee; I. Leedom; J. M. Le Goff; L. Leistam; R. Leiste; M. Lenti; E. Leonardi; J. Lettry; P. M. Levchenko; X. Leytens; C. Li; H. T. Li; J. F. Li; L. Li; P. J. Li; Q. Li; X. G. Li; J. Y. Liao; Z. Y. Lin; F. L. Linde; B. Lindemann; D. Linnhofer; R. Liu; Y. Liu; W. Lohmann; E. Longo; Y. S. Lu; J. M. Lubbers; K. Lübelsmeyer; C. Luci; D. Luckey; L. Ludovici; L. Luminari; W. G. Ma; M. MacDermott; R. Magahiz; P. K. Malhotra; R. Malik; A. Malinin; C. Maña; D. N. Mao; Y. F. Mao; M. Maolinbay; P. Marchesini; A. Marchionni; J. P. Martin; L. Martinez-Laso; F. Marzano; G. G. G. Massaro; T. Matsuda; K. Mazumdar; P. McBride; T. McMahon; D. McNally; Th. Meinholz; M. Merk; L. Merola; M. Meschini; W. J. Metzger; Y. Mi; G. B. Mills; Y. Mir; G. Mirabelli; J. Mnich; M. Möller; B. Monteleoni; G. Morand; R. Morand; S. Morganti; N. E. Moulai; R. Mount; S. Müller; E. Nagy; M. Napolitano; H. Newman; C. Neyer; M. A. Niaz; L. Niessen; H. Nowak; D. Pandoulas; M. Pauluzzi; F. Pauss; F. Plasil; G. Passaleva; S. Patricelli; Y. J. Pei; D. Perret-Gallix; J. Perrier; A. Pevsner; M. Pieri; P. A. Piroué; V. Plyaskin; V. Pojidaev; N. Produit; J. M. Qian; K. N. Qureshi; R. Raghavan; G. Rahal-Callot; G. Raven; P. Razis; K. Read; D. Ren; Z. Ren; S. Reucroft; A. Ricker; S. Riemann; O. Rind; C. Rippich; H. A. Rizvi; B. P. Roe; M. Röhner; S. Röhner; L. Romero; J. Rose; S. Rosier-Lees; R. Rosmalen; Ph. Rosselet; A. Rubbia; J. A. Rubio; W. Ruckstuhl; H. Rykaczewski; M. Sachwitz; J. Salicio; G. Sanders; A. Santocchia; M. S. Sarakinos; G. Sartorelli; G. Sauvage; V. Schegelsky; K. Schmiemann; D. Schmitz; P. Schmitz; M. Schneegans; H. Schopper; D. J. Schotanus; S. Shotkin; H. J. Schreiber; R. Schulte; S. Schulte; K. Schultze; J. Schütte; J. Schwenke; G. Schwering; C. Sciacca; I. Scott; R. Sehgal; P. G. Seiler; J. C. Sens; L. Servoli; I. Sheer; D. Z. Shen; V. Shevchenko; S. Shevchenko; X. R. Shi; K. Shmakov; E. Shumilov; N. Smirnov; E. Soderstrom; A. Sopczak; C. Spartiotis; T. Spickermann; P. Spillantini; R. Starosta; M. Steur; D. P. Stickland; F. Sticozzi; W. Stoeff; H. Stone; K. Strauch; B. C. Stringfellow; K. Sudhakar; G. Sultanov; R. L. Sumner; L. Z. Sun; H. Suter; R. B. Sutton; J. D. Swain; A. A. Syed; X. W. Tang; E. Tarkovsky

    1991-01-01

    From a fit to the impact parameter distribution of lepton tracks from semileptonic b decay, the lifetime of B-hadrons produced in e+e- collisions at the Z0 is measured to be 1.32+\\/-0.08 (stat.)+\\/-0.09(syst.) ps. Combined with an earlier measurement of the branching ratio Br(B-->lnuX), the CKM matrix element Vcb is determined to be 0.046+\\/-0.002 (exp.)-0.003+0.004 (theory). Supported by the German Bundesministerium

  2. Measurement of the B hadron lifetime from Mark II at PEP

    SciTech Connect

    Ong, R.A.

    1988-01-01

    Using data taken by the Mark II detector at PEP, the decays of B hadrons are tagged by identifying leptons at high transverse momentum. By means of a precision inner drift chamber, the impact parameters of these leptons are measured with respect to the B production point. From this impact parameter distribution, the B hadron lifetime is found to be 0.98 +- 0.12 +- 0.13 ps. This measurement can be used to place constraints models of quark mixing. 11 refs., 2 figs., 2 tabs.

  3. Development of a new time and position resolving detector for the pulsed low energy positron system PLEPS

    NASA Astrophysics Data System (ADS)

    Ackermann, U.; Egger, W.; Sperr, P.; Löwe, B.; Ravelli, L.; Kögel, G.; Dollinger, G.; Jagutzki, O.

    2013-06-01

    The pulsed low energy positron system PLEPS at the Munich research reactor FRM-II is a user facility for depth resolved positron lifetime measurements. Besides positron lifetime measurements 2D-AMOC (Two Dimensional Age Momentum Correlation) experiments are also possible. 2D-AMOC provides in coincidence the lifetime of the positron and the longitudinal momentum distribution of the annihilated electron. It would be of great scientific concern to measure simultaneously the entire 3D-momentum distribution of the electron annihilating with the positron and the corresponding lifetime of the positron (4D-AMOC). To perform 4D-AMOC measurements a time and position resolving detector is required in coincidence with a pixelated Germanium detector. Therefore a time and spatially resolving detector is currently developed at our institute with envisaged time resolution of 100 ps (FWHM) and a spatial resolution of about 2.6 mm (FWHM) over an area of 12 cm2. First test measurements have been carried out with a 25 mm diameter MCP (Micro Channel Plate) image intensifier and with special delay-line anode readout for the spatial information. Up to now 178 ps (FWHM) time resolution and on average 3.4 mm (FWHM) position resolution have been achieved with BaF2 as scintillator material and a 60Co source.

  4. Positron Annihilation in Superconducting 123 Compounds

    NASA Astrophysics Data System (ADS)

    Peter, M.; Manuel, A. A.; Erb, A.

    After a brief review of the theory of angular correlation of positron annihilation radiation (ACAR), we illustrate experimental principles and give examples of successful determination of electron momentum density (EMD) and of positron lifetime in solids. The central question which we try to answer concerns the contribution of positron spectroscopy to the knowledge and understanding of the new high temperature superconducting oxides. We find that in these oxides also, partially filled bands exist and we can observe parts of their Fermi surface and measure lifetimes in accordance with band theoretical calculations. There are characteristic differences, however. The intensity of the anisotropy of the ACAR signal is below theoretical expectation and signals depend on sample preparation. Recent studies by the Geneva group have concerned dependence of the signals on impurities, on oxygen content and on the thermal history of preparation. Of particular interest are correlations between the variations of these signals and between the variations of structural and transport properties in these substances. Besides deliberate additions of impurities, the Geneva group also reports progress in the preparations of samples of highest purity (barium zirconate crucibles). The alloy series PrxY1-xBa2Cu3O7-? is of special interest because of exceptional transport properties. The recent positron results on these materials will be presented and commented in the light of theoretical models and in the light of the reported superconductivity of the Pr-compound.

  5. Positron annihilation study on free volume of amino acid modified, starch-grafted acrylamide copolymer

    NASA Astrophysics Data System (ADS)

    Mahmoud, K. R.; Al-Sigeny, S.; Sharshar, T.; El-Hamshary, H.

    2006-05-01

    Free volume measurements using positron annihilation lifetime spectroscopy was performed for uncrosslinked and crosslinked starch-grafted polyacrylamide, and their modified amino acid samples including some of their iron(III) complexes. The measurements were performed at room temperature. The analysis of lifetime spectra yielded mostly three lifetime components. It was observed that the values of the short lifetime component ?1 are slightly higher than the lifetime associated with the self-decay of para-positronium atoms in polymers. The free volume was probed using ortho-positronium pick-off annihilation lifetime parameters. The mean free volume has also been calculated from the lifetime data. The avrage value of this parameter of the crosslinked polymer were found to be higher than those of the uncrosslinked polymer.

  6. Image properties of list mode likelihood reconstruction for a rectangular positron emission mammography with DOI measurements

    SciTech Connect

    Qi, Jinyi; Klein, Gregory J.; Huesman, Ronald H.

    2000-10-01

    A positron emission mammography scanner is under development at our Laboratory. The tomograph has a rectangular geometry consisting of four banks of detector modules. For each detector, the system can measure the depth of interaction information inside the crystal. The rectangular geometry leads to irregular radial and angular sampling and spatially variant sensitivity that are different from conventional PET systems. Therefore, it is of importance to study the image properties of the reconstructions. We adapted the theoretical analysis that we had developed for conventional PET systems to the list mode likelihood reconstruction for this tomograph. The local impulse response and covariance of the reconstruction can be easily computed using FFT. These theoretical results are also used with computer observer models to compute the signal-to-noise ratio for lesion detection. The analysis reveals the spatially variant resolution and noise properties of the list mode likelihood reconstruction. The theoretical predictions are in good agreement with Monte Carlo results.

  7. Near Infrared Dyes as Lifetime Solvatochromic Probes for Micropolarity Measurements of Biological Systems

    PubMed Central

    Berezin, Mikhail Y.; Lee, Hyeran; Akers, Walter; Achilefu, Samuel

    2007-01-01

    The polarity of biological mediums controls a host of physiological processes such as digestion, signaling, transportation, metabolism, and excretion. With the recent widespread use of near-infrared (NIR) fluorescent dyes for biological imaging of cells and living organisms, reporting medium polarity with these dyes would provide invaluable functional information in addition to conventional optical imaging parameters. Here, we report a new approach to determine polarities of macro- and microsystems for in vitro and potential in vivo applications using NIR polymethine molecular probes. Unlike the poor solvatochromic response of NIR dyes in solvents with diverse polarity, their fluorescence lifetimes are highly sensitive, increasing by a factor of up to 8 on moving from polar to nonpolar mediums. We also established a correlation between fluorescence lifetime and solvent orientation polarizability and developed a lifetime polarity index for determining the polarity of complex systems, including micelles and albumin binding sites. Because of the importance of medium polarity in molecular, cellular, and biochemical processes and the significance of reduced autofluorescence and deep tissue penetration of light in the NIR region, the findings reported herein represent an important advance toward using NIR molecular probes to measure the polarity of complex biological systems in vitro and in vivo. PMID:17573433

  8. Design and construction of a Vertex Chamber and measurement of the average B-Hadron lifetime

    SciTech Connect

    Nelson, H.N.

    1987-10-01

    Four parameters describe the mixing of the three quark generations in the Standard Model of the weak charged current interaction. These four parameters are experimental inputs to the model. A measurement of the mean lifetime of hadrons containing b-quarks, or B-Hadrons, constrains the magnitudes of two of these parameters. Measurement of the B-Hadron lifetime requires a device that can measure the locations of the stable particles that result from B-Hadron decay. This device must function reliably in an inaccessible location, and survive high radiation levels. We describe the design and construction of such a device, a gaseous drift chamber. Tubes of 6.9 mm diameter, having aluminized mylar walls of 100 ..mu..m thickness are utilized in this Vertex Chamber. It achieves a spatial resolution of 45 ..mu..m, and a resolution in extrapolation to the B-Hadron decay location of 87 ..mu..m. Its inner layer is 4.6 cm from e/sup +/e/sup -/ colliding beams. The Vertex Chamber is situated within the MAC detector at PEP. We have analyzed botht he 94 pb/sup -1/ of integrated luminosity accumulated at ..sqrt..s = 29 GeV with the Vertex Chamber in place as well as the 210 pb/sup -1/ accumulated previously. We require a lepton with large momentum transverse to the event thrust axis to obtain a sample of events enriched in B-Hadron decays. The distribution of signed impact parameters of all tracks in these events is used to measure the B-Hadron flight distance, and hence lifetime. 106 refs., 79 figs., 20 tabs.

  9. High-resolution positron Q-value measurements and nuclear-structure studies far from the stability line. Progress report

    SciTech Connect

    Avignone, F.T. III.

    1981-02-28

    Extensive data analysis and theoretical analysis has been done to complete the extensive decay scheme investigation of /sup 206/ /sup 208/Fr and the level structures of /sup 206/ /sup 208/Rn. A final version of a journal article is presented in preprint form. Extensive Monte Carlo calculations have been made to correct the end point energies of positron spectra taken with intrinsic Ge detectors for annihilation radiation interferences. These calculations were tested using the decay of /sup 82/Sr which has previously measured positron branches. This technique was applied to the positron spectra collected at the on-line UNISOR isotope separator. The reactions used were /sup 60/Ni(/sup 20/Ne;p2n)/sup 77/Rb and /sup 60/Ni(/sup 20/Ne;pn)/sup 78/Rb. Values for 5, ..gamma..-..beta../sup +/ coincidence positron end point energies are given for the decay of /sup 77/Rb. The implied Q-value is 5.075 +- 0.010 MeV. A complete paper on the calculated corrections is presented. A flow chart of a more complete program which accounts for positrons scattering out of the detector and for bremsstralung radiation is also presented. End-point energies of four ..beta../sup +/ branches in /sup 77/Rb are given as well as a proposed energy level scheme of /sup 75/Kr based on ..gamma..-..gamma.. coincidence data taken at UNISOR.

  10. Positron-annihilation study of voids in aSi and aSi:H

    Microsoft Academic Search

    Y. J. He; M. Hasegawa; R. Lee; S. Berko; David Adler; Ai-Lien Jung

    1986-01-01

    Angular correlation of positron-electron annihilation radiation (ACAR) experiments and positron-lifetime measurements have been performed in a-Si and a-Si:H films as a function of temperature. Positronium formation in microvoids is observed in a-Si:H, but not in a-Si. From the width of the narrow positronium ACAR components we estimate the average diameter of the microvoids to be ~20 Å. A complex temperature

  11. Mechanical durability of polymeric coatings studied by positron annihilation spectroscopy: correlation between cyclic loading and free volumes

    NASA Astrophysics Data System (ADS)

    Chen, H.; Peng, Q.; Huang, Y. Y.; Zhang, R.; Mallon, P. E.; Zhang, J.; Li, Y.; Wu, Y.; Richardson, J. R.; Sandreczki, T. C.; Jean, Y. C.; Suzuki, R.; Ohdaira, T.

    2002-06-01

    The mechanical durability of seven commercially polymeric coatings is investigated using slow positron beam techniques to monitor changes in sub-nanometer defects during the process of cyclic loading. Doppler broadened energy spectra and positron annihilation lifetime (PAL) measurements were performed as a function of the slow positron energy at different periods of cycling loading. The positron annihilation dada show that both S-defect parameter and o-positronium (Ps) lifetime decrease as the loading cycle increases. The results indicate a loss of free volumes due to the loss of mechanical durability by cyclic loading. A direct correlation between the loss of S-defect parameter and the period of loading cycle is observed. This is interpreted as that durability of polymeric coatings is controlled by the atomic level free volumes. It is shown that the slow positron beam is a very successful probe in detecting the very early stages of coating degradation due to mechanical processes.

  12. Confronting recent AMS-02 positron fraction and Fermi-LAT Extragalactic Gamma-Ray Background measurements with gravitino dark matter

    E-print Network

    Edson Carquin; Marco A. Diaz; German A. Gomez-Vargas; Boris Panes; Nicolas Viaux

    2015-04-13

    The positron fraction measured by the space-based detectors PAMELA, {\\it Fermi}-LAT and AMS-02 presents anomalous behaviour as energy increase. In particular AMS-02 observations provide compelling evidence for a new source of positrons and electrons. Its origin is unknown, it can be non-exotic (e.g. pulsars), be dark matter (DM) or maybe a mixture. We test the gravitino of bilinear R-parity violating supersymmetric models as this source. As the gravitino is a spin 3/2 particle, it offers particular decay channels, $W^{\\pm}l^{\\mp}_i$, $Z\

  13. Development of a Precision Neutron Lifetime Measurement: Magnetic Trapping of Ultracold Neutrons

    NASA Astrophysics Data System (ADS)

    O'Shaughnessy, Christopher Martin

    The neutron lifetime plays an important role in both nuclear astrophysics and in furthering the understanding of weak interactions in the Standard Model. It is the most important experimental parameter in theoretical predictions of the primordial abundance of 4He in Big Bang Nucleosynthesis. A precision measurement also provides a self consistency check of the unitarity of the CKM mixing matrix which relates the weak and mass eigenstates of quarks in the Standard Model. Our group has successfully demonstrated the trapping of ultracold neutrons in a conservative potential magnetic trap and demonstrated that the measured lifetime was consistent with the present world average value. This work represents a major upgrade of the apparatus assembled at the NIST Center for Neutron Research to address statistical limitations of the former measurement. Our unique approach to this measurement and the advantages it provides over other techniques will be discussed. The major systematics of the technique will be addressed. Tests of the upgrade components and details of the final stages of construction will also be presented.

  14. Electron and Positron Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

    E-print Network

    Becker, Ulrich J.

    Precision measurements by the Alpha Magnetic Spectrometer on the International Space Station of the primary cosmic-ray electron flux in the range 0.5 to 700 GeV and the positron flux in the range 0.5 to 500 GeV are presented. ...

  15. Predicted CALET measurements of electron and positron spectra from 3 to 20 GeV using the geomagnetic field

    NASA Astrophysics Data System (ADS)

    Rauch, B. F.

    2014-05-01

    The CALorimetric Electron Telescope (CALET) is an imaging calorimeter under construction for launch to the ISS in 2014 for a planned 5 year mission. CALET consists of a charge detection module (CHD) with two segmented planes of 1 cm thick plastic scintillator, an imaging calorimeter (IMC) with a total of 3 radiation lengths (X?) of tungsten plates read out with 8 planes of interleaved scintillating fibers, and a total absorption calorimeter (TASC) with 27 X? of lead tungstate (PWO) logs. The primary objectives of the experiment are to measure the electron e+e energy spectra from 1 GeV to 20 TeV, to detect gamma-rays above 10 GeV, and to measure the energy spectra of nuclei from protons through iron up to 1000 TeV. In this paper we describe how the geomagnetic field at the 51.6° inclination orbit of the ISS can be used to allow CALET to measure the distinct electron and positron fluxes. The positron fraction has been seen to rise above ˜10 GeV by previous experiments (HEAT, AMS-01), and more recently to continue to increase to higher energies (˜80 GeV for PAMELA, ˜200 GeV for Fermi and ˜350 GeV with the best statistics for AMS-02). Utilizing the geomagnetic cutoff, CALET will be able to distinguish electrons and positrons in the ˜3-20 GeV energy range where the positron fraction turns upward to complement existing high statistics measurements.

  16. Measurement of the $B^{+}$ and $B^{0}$ lifetimes and search for CP(T) violation using reconstructed secondary vertices

    Microsoft Academic Search

    G Abbiendi; K Ackerstaff; Gideon Alexander; J Allison; N Altekamp; K J Anderson; S Anderson; S Arcelli; S Asai; S F Ashby; D A Axen; Georges Azuelos; A H Ball; E Barberio; R J Barlow; R Bartoldus; J Richard Batley; S Baumann; J Bechtluft; T Behnke; K W Bell; G Bella; A Bellerive; Stanislaus Cornelius Maria Bentvelsen; Siegfried Bethke; S Betts; O Biebel; A Biguzzi; S D Bird; Volker Blobel; Ian J Bloodworth; P Bock; J Böhme; D Bonacorsi; M Boutemeur; S Braibant; P G Bright-Thomas; L Brigliadori; R M Brown; Helfried J Burckhart; P Capiluppi; R K Carnegie; A A Carter; J R Carter; C Y Chang; D G Charlton; D Chrisman; C Ciocca; P E L Clarke; E Clay; I Cohen; J E Conboy; O C Cooke; C Couyoumtzelis; R L Coxe; M Cuffiani; S Dado; G M Dallavalle; R Davis; S De Jong; A de Roeck; P J Dervan; Klaus Desch; B Dienes; M S Dixit; J Dubbert; E Duchovni; G Duckeck; I P Duerdoth; D Eatough; P G Estabrooks; E Etzion; Franco Luigi Fabbri; M Fanti; A A Faust; F Fiedler; M Fierro; I Fleck; R Folman; A Fürtjes; D I Futyan; P Gagnon; J W Gary; J Gascon; S M Gascon-Shotkin; G Gaycken; C Geich-Gimbel; G Giacomelli; P Giacomelli; V Gibson; W R Gibson; D M Gingrich; D A Glenzinski; J Goldberg; W Gorn; C Grandi; K Graham; E Gross; Jacob Grunhaus; M Gruwé; G G Hanson; M Hansroul; M Hapke; K Harder; A Harel; C K Hargrove; C Hartmann; M Hauschild; C M Hawkes; R Hawkings; Richard J Hemingway; M Herndon; G Herten; R D Heuer; M D Hildreth; J C Hill; P R Hobson; M Hoch; Andreas Höcker; K Hoffman; R James Homer; A K Honma; D Horváth; K R Hossain; R Howard; P Hüntemeyer; P Igo-Kemenes; D C Imrie; K Ishii; F R Jacob; A Jawahery; H Jeremie; Martin Paul Jimack; C R Jones; P Jovanovic; T R Junk; D A Karlen; V G Kartvelishvili; K Kawagoe; T Kawamoto; P I Kayal; Richard K Keeler; R G Kellogg; B W Kennedy; D H Kim; A Klier; S Kluth; T Kobayashi; M Kobel; D S Koetke; T P Kokott; M Kolrep; S Komamiya; R V Kowalewski; T Kress; P Krieger; J Von Krogh; T Kühl; P Kyberd; G D Lafferty; Hagar Yaël Landsman; D Lanske; J Lauber; S R Lautenschlager; I Lawson; J G Layter; D Lazic; A M Lee; Daniel Lellouch; J Letts; L Levinson; R Liebisch; B List; C Littlewood; A W Lloyd; S L Lloyd; F K Loebinger; G D Long; Michael J Losty; J Ludwig; D Liu; A Macchiolo; A L MacPherson; W F Mader; M Mannelli; S Marcellini; C Markopoulos; A J Martin; J P Martin; G Martínez; T Mashimo; P Mättig; W J McDonald; J A McKenna; E A McKigney; T J McMahon; R A McPherson; F Meijers; S Menke; F S Merritt; H Mes; J Meyer; Aldo Michelini; S Mihara; G Mikenberg; D J Miller; R Mir; W Mohr; A Montanari; T Mori; K Nagai; I Nakamura; H A Neal; B Nellen; R Nisius; S W O'Neale; F G Oakham; F Odorici; H O Ögren; M J Oreglia; S Orito; J Pálinkás; G Pásztor; J R Pater; G N Patrick; J Patt; R Pérez-Ochoa; S Petzold; P Pfeifenschneider; J E Pilcher; James L Pinfold; D E Plane; P R Poffenberger; J Polok; M B Przybycien; C Rembser; Hartmut Rick; S Robertson; S A Robins; N L Rodning; J M Roney; K Roscoe; A M Rossi; Y Rozen; K Runge; O Runólfsson; D R Rust; K Sachs; T Saeki; O Sahr; W M Sang; E Sarkisyan-Grinbaum; C Sbarra; A D Schaile; O Schaile; F Scharf; P Scharff-Hansen; J Schieck; B Schmitt; S Schmitt; A Schöning; M Schröder; M Schumacher; C Schwick; W G Scott; R Seuster; T G Shears; B C Shen; C H Shepherd-Themistocleous; P Sherwood; G P Siroli; A Sittler; A Skuja; A M Smith; G A Snow; Randall J Sobie; S Söldner-Rembold; S Spagnolo; M Sproston; A Stahl; K Stephens; J Steuerer; K Stoll; D Strom; R Ströhmer; B Surrow; S D Talbot; S Tanaka; P Taras; S Tarem; R Teuscher; M Thiergen; J Thomas; M A Thomson; E Von Törne; E Torrence; S Towers; I Trigger; Z L Trócsányi; E Tsur; A S Turcot; M F Turner-Watson; I Ueda; R Van Kooten; P Vannerem; M Verzocchi; H Voss; F Wäckerle; A Wagner; C P Ward; D R Ward; P M Watkins; A T Watson; N K Watson; P S Wells; N Wermes; J S White; G W Wilson; J A Wilson; T R Wyatt; S Yamashita; G Yekutieli; V Zacek; D Zer-Zion

    1998-01-01

    The lifetimes of the B+ and B0 mesons, and their ratio, have been measured in the OPAL experiment using 2.4 million hadronic Z0 decays recorded at LEP. Z0 -> b bbar decays were tagged using displaced secondary vertices and high momentum electrons and muons. The lifetimes were then measured using well-reconstructed charged and neutral secondary vertices selected in this tagged

  17. Experimental measurements of charge carrier mobility: lifetime products for large sample of pixilated CZT detectors

    NASA Astrophysics Data System (ADS)

    Vadawale, S. V.; Shanmugam, M.; Purohit, Shishir; Acharya, Y. B.; Sudhakar, Manju

    2012-07-01

    Cadmium-Zinc-Telluride (CZT) is thought to be a primary work horse for hard X-ray astronomy in future. Due to the relatively large band-gap, it offers near room temperature operation while maintaining much better energy resolution then scintillator detectors operating in similar energy range. Further, CZT detectors are available in the form of pixilated detectors with area up to few cm2 and hence it is possible to realize very large detector area by having an array of such pixilated CZT detectors. However, it is well known that the energy spectrum of mono-energetic X-ray measured by CZT detectors does not have a Gaussian shape but has significant low-energy tail. This is mainly due to relatively poor mobility and small life time of the charge carriers, particularly of holes, in the CZT crystals. Thus, in order to understand spectral response for a large array of CZT detectors consisting of multiple elements / pixels, it is essential to characterize the mobility-lifetime products of charge carriers for each individual elements / pixels. Here we present experimental measurements of charge carrier mobility-lifetime products for large sample of multi-pixel CZT detectors. The mobility-lifetime products are measured by simultaneously fitting a ‘CZT line’ model to pixel wise spectra of 122 keV X-rays from 57Co at three different bias voltages. These were carried out as a part of selection of CZT detector modules for the “High Energy X-ray spectrometer (HEX)” onboard Indian moon mission - Chandrayaan-1.

  18. Measurements of the luminescence lifetimes of Europium (III) ion in nitrilotriacetic acid (NTA) aqueous solution system

    NASA Astrophysics Data System (ADS)

    Stryla, Zdzislaw; Lis, S.; Hnatejko, Z.; Elbanowski, M.

    1995-03-01

    Time-resolved laser induced fluorescence spectroscopy has been used to study complexation of Eu(III) ion with nitrilotriacetic acid (NTA). An experimental setup consisting of the nitrogen laser pumped tunable dye laser and two different detection devices has been built and extensively tested. Using this apparatus, the lifetimes of the 5D0 level of Eu(III) ion in complexes with NTA in water solution for 2:1, 1:1, 1:2 Eu:NTA molar ratios over the wide pH range have been measured.

  19. Measurement of lifetime and decay-width difference in BS(0)-> J\\/psi phi decays

    Microsoft Academic Search

    T. Aaltonen; A. Abulencia; J. Adelman; T. Akimoto; M. G. Albrow; B. A. Gonzalez; S. Amerio; D. Amidei; A. Anastassov; A. Annovi; J. Antos; G. Apollinari; A. Apresyan; T. Arisawa; A. Artikov; W. Ashmanskas; A. Attal; A. Aurisano; F. Azfar; P. Azzi-Bacchetta; P. Azzurri; N. Bacchetta; W. Badgett; A. Barbaro-Galtieri; V. E. Barnes; B. A. Barnett; S. Baroiant; V. Bartsch; G. Bauer; P. H. Beauchemin; F. Bedeschi; P. Bednar; S. Behari; G. Bellettini; J. Bellinger; A. Belloni; D. Benjamin; A. Beretvas; J. Beringer; T. Berry; A. Bhatti; M. Binkley; D. Bisello; I. Bizjak; R. E. Blair; C. Blocker; B. Blumenfeld; A. Bocci; A. Bodek; V. Boisvert; G. Bolla; A. Bolshov; D. Bortoletto; J. Boudreau; A. Boveia; B. Brau; L. Brigliadori; C. Bromberg; E. Brubaker; J. Budagov; H. S. Budd; S. Budd; K. Burkett; G. Busetto; P. Bussey; A. Buzatu; K. L. Byrum; S. Cabrera; M. Campanelli; M. Campbell; F. Canelli; A. Canepa; D. Carlsmith; R. Carosi; S. Carrillo; S. Carron; B. Casal; M. Casarsa; A. Castro; P. Catastini; D. Cauz; M. Cavalli-Sforza; A. Cerri; L. Cerrito; S. H. Chang; Y. C. Chen; M. Chertok; G. Chiarelli; G. Chlachidze; F. Chlebana; K. Cho; D. Chokheli; J. P. Chou; G. Choudalakis; S. H. Chuang; K. Chung; W. H. Chung; Y. S. Chung; C. I. Ciobanu; M. A. Ciocci; A. Clark; D. Clark; G. Compostella; M. E. Convery; J. Conway; B. Cooper; K. Copic; M. Cordelli; G. Cortiana; F. Crescioli; C. C. Almenar; J. Cuevas; R. Culbertson; J. C. Cully; D. Dagenhart; M. Datta; T. Davies; P. de Barbaro; S. De Cecco; A. Deisher; G. De Lentdecker; G. De Lorenzo; M. DellOrso; L. Demortier; J. Deng; M. Deninno; D. De Pedis; P. F. Derwent; G. P. Di Giovanni; C. Dionisi; B. Di Ruzza; J. R. Dittmann; M. DOnofrio; S. Donati; P. Dong; J. Donini; T. Dorigo; S. Dube; J. Efron; R. Erbacher; D. Errede; S. Errede; R. Eusebi; H. C. Fang; S. Farrington; W. T. Fedorko; R. G. Feild; M. Feindt; J. P. Fernandez; C. Ferrazza; R. Field; G. Flanagan; R. Forrest; S. Forrester; M. Franklin; J. C. Freeman; I. Furic; M. Gallinaro; J. Galyardt; F. Garberson; J. E. Garcia; A. F. Garfinkel; H. Gerberich; D. Gerdes; S. Giagu; P. Giannetti; K. Gibson; J. L. Gimmell; C. M. Ginsburg; N. Giokaris; M. Giordani; P. Giromini; M. Giunta; V. Glagolev; D. Glenzinski; M. Gold; N. Goldschmidt; A. Golossanov; G. Gomez; G. Gomez-Ceballos; M. Goncharov; O. Gonzalez; I. Gorelov; A. T. Goshaw; K. Goulianos; A. Gresele; S. Grinstein; C. Grosso-Pilcher; U. Grundler; J. G. da Costa; Z. Gunay-Unalan; C. Haber; K. Hahn; S. R. Hahn; E. Halkiadakis; B. Y. Han; J. Y. Han; R. Handler; F. Happacher; K. Hara; D. Hare; M. Hare; S. Harper; R. F. Harr; R. M. Harris; M. Hartz; K. Hatakeyama; J. Hauser; C. Hays; M. Heck; A. Heijboer; B. Heinemann; J. Heinrich; C. Henderson; M. Herndon; J. Heuser; S. Hewamanage; D. Hidas; C. S. Hill; D. Hirschbuehl; A. Hocker; S. Hou; M. Houlden; S. C. Hsu; B. T. Huffman; R. E. Hughes; U. Husemann; J. Huston; J. Incandela; G. Introzzi; M. Iori; A. Ivanov; B. Iyutin; E. James; B. Jayatilaka; D. Jeans; E. J. Jeon; S. Jindariani; W. Johnson; M. Jones; K. K. Joo; S. Y. Jun; J. E. Jung; T. R. Junk; T. Kamon; D. Kar; P. E. Karchin; Y. Kato; R. Kephart; U. Kerzel; V. Khotilovich; B. Kilminster; D. H. Kim; H. S. Kim; J. E. Kim; M. J. Kim; S. B. Kim; S. H. Kim; Y. K. Kim; N. Kimura; L. Kirsch; S. Klimenko; M. Klute; B. Knuteson; B. R. Ko; S. A. Koay; K. Kondo; D. J. Kong; J. Konigsberg; A. Korytov; A. V. Kotwal; J. Kraus; M. Kreps; J. Kroll; N. Krumnack; M. Kruse; V. Krutelyov; T. Kubo; S. E. Kuhlmann; T. Kuhr; N. P. Kulkarni; Y. Kusakabe; S. Kwang; A. T. Laasanen; S. Lai; S. Lami; S. Lammel; M. Lancaster; R. L. Lander; K. Lannon; A. Lath; G. Latino; I. Lazzizzera; T. LeCompte; J. Lee; Y. J. Lee; S. W. Lee; R. Lefevre; N. Leonardo; S. Leone; S. Levy; J. D. Lewis; C. Lin; M. Lindgren; E. Lipeles; A. Lister; D. O. Litvintsev; T. Liu; N. S. Lockyer; A. Loginov; M. Loreti; L. Lovas; R. S. Lu; D. Lucchesi; J. Lueck; C. Luci; P. Lujan; P. Lukens; G. Lungu; L. Lyons; J. Lys; R. Lysak; E. Lytken; P. Mack; D. MacQueen; R. Madrak; K. Maeshima; K. Makhoul; T. Maki; P. Maksimovic; S. Malde; S. Malik; G. Manca; A. Manousakis; F. Margaroli; C. Marino; A. Martin; M. Martin; V. Martin; M. Martinez; R. Martinez-Ballarin; T. Maruyama; P. Mastrandrea; T. Masubuchi; M. E. Mattson; P. Mazzanti; K. S. McFarland; P. McIntyre; R. McNulty; A. Mehta; P. Mehtala; S. Menzemer; A. Menzione; P. Merkel; C. Mesropian; A. Messina; T. Miao; N. Miladinovic; J. Miles; R. Miller; C. Mills; M. Milnik; A. Mitra; G. Mitselmakher; H. Miyake; S. Moed; N. Moggi; C. S. Moon; R. Moore; M. Morello; P. M. Fernandez; J. Mulmenstadt; A. Mukherjee; T. Muller; R. Mumford; P. Murat; M. Mussini; J. Nachtman; Y. Nagai; A. Nagano; J. Naganoma; K. Nakamura; I. Nakano; A. Napier; V. Necula; C. Neu; M. S. Neubauer; J. Nielsen; L. Nodulman; M. Norman; O. Norniella; E. Nurse; S. H. Oh; Y. D. Oh; I. Oksuzian; T. Okusawa; R. Oldeman

    2008-01-01

    We measure the mean lifetime tau=2\\/(Gamma(L)+Gamma(H)) and the decay-width difference Delta Gamma=Gamma(L)-Gamma(H) of the light and heavy mass eigenstates of the B-s(0) meson, B-sL(0) and B-sH(0), in B-s(0)-> J\\/psi phi decays using 1.7 fb(-1) of data collected with the CDF II detector at the Fermilab Tevatron pp collider. Assuming CP conservation, a good approximation for the B-s(0) system in the

  20. Measured lifetimes of metastable levels of Mn X, Mn XI, Mn XII, and Mn XIII ions 

    E-print Network

    Moehs, D. P.; Church, David A.

    1999-01-01

    . The measured lifetimes are tau(Mn X, 3s(2)3p(4) S-1(0)) = 2.1 +/- 0.3, tau(Mn X, 3s(2)3p(4) D-1(2)) = 18.02 +/- 0.16, tau(Mn XI, 3s(2)3p(3) P-2(3/2)) = 3.0 +/- 0.2, tau(Mn XI, 3s(2)3p(3) P-2(1/2)) = 6.17 +/- 0.29, tau(Mn XI, 3s(2)3p(3) D-2(3/2)) = 35.1 +/- 1...

  1. Lifetime measurement of the first excited 2+ state in 112Te

    NASA Astrophysics Data System (ADS)

    Doncel, M.; Bäck, T.; Cullen, D. M.; Hodge, D.; Qi, C.; Cederwall, B.; Taylor, M. J.; Procter, M.; Auranen, K.; Grahn, T.; Greenlees, P. T.; Jakobsson, U.; Julin, R.; Juutinen, S.; Herzán, A.; Konki, J.; Leino, M.; Pakarinen, J.; Partanen, J.; Peura, P.; Rahkila, P.; Ruotsalainen, P.; Sandzelius, M.; Sarén, J.; Scholey, C.; Sorri, J.; Stolze, S.; Uusitalo, J.

    2015-06-01

    The lifetime of the 2+?0g.s . + transition in the neutron-deficicient nucleus 112Te has been measured for the first time using the DPUNS plunger and the recoil distance Doppler shift technique. The deduced value for the reduced transition probability is B (E 2 : 0g.s . +?2+) =0.46 ±0.04 e2b2 , indicating that there is no unexpected enhancement of the B (E 2 : 0g.s . +?2+) values in Te isotopes below the midshell. The result is compared to and discussed in the framework of large-scale shell-model calculations.

  2. Measurement of the B 0 lifetime and oscillation frequency using B ? 0? D ?+? ? ? ? decays

    Microsoft Academic Search

    G. Abbiendi; K. Ackerstaff; C. Ainsley; P. F. Åkesson; G. Alexander; J. Allison; K. J. Anderson; S. Arcelli; S. Asai; S. F. Ashby; D. Axen; G. Azuelos; I. Bailey; A. H. Ball; E. Barberio; R. J. Barlow; S. Baumann; T. Behnke; K. W. Bell; G. Bella; A. Bellerive; G. Benelli; S. Bentvelsen; S. Bethke; O. Biebel; I. J. Bloodworth; O. Boeriu; P. Bock; J. Böhme; D. Bonacorsi; M. Boutemeur; S. Braibant; P. Bright-Thomas; L. Brigliadori; R. M. Brown; H. J. Burckhart; J. Cammin; P. Capiluppi; R. K. Carnegie; A. A. Carter; J. R. Carter; C. Y. Chang; D. G. Charlton; P. E. L. Clarke; E. Clay; I. Cohen; O. C. Cooke; J. Couchman; C. Couyoumtzelis; R. L. Coxe; A. Csilling; M. Cuffiani; S. Dado; G. M. Dallavalle; S. Dallison; A. de Roeck; E. de Wolf; P. Dervan; K. Desch; B. Dienes; M. S. Dixit; M. Donkers; J. Dubbert; E. Duchovni; G. Duckeck; I. P. Duerdoth; P. G. Estabrooks; E. Etzion; F. Fabbri; M. Fanti; L. Feld; P. Ferrari; F. Fiedler; I. Fleck; M. Ford; A. Frey; A. Fürtjes; D. I. Futyan; P. Gagnon; J. W. Gary; G. Gaycken; C. Geich-Gimbel; G. Giacomelli; P. Giacomelli; D. Glenzinski; J. Goldberg; C. Grandi; K. Graham; E. Gross; J. Grunhaus; M. Gruwé; P. O. Günther; C. Hajdu; G. G. Hanson; M. Hansroul; M. Hapke; K. Harder; A. Harel; M. Harin-Dirac; A. Hauke; M. Hauschild; C. M. Hawkes; R. Hawkings; R. J. Hemingway; C. Hensel; G. Herten; R. D. Heuer; J. C. Hill; A. Hocker; K. Hoffman; R. J. Homer; A. K. Honma; D. Horváth; K. R. Hossain; R. Howard; P. Hüntemeyer; P. Igo-Kemenes; K. Ishii; F. R. Jacob; A. Jawahery; H. Jeremie; C. R. Jones; P. Jovanovic; T. R. Junk; N. Kanaya; J. Kanzaki; G. Karapetian; D. Karlen; V. Kartvelishvili; K. Kawagoe; T. Kawamoto; R. K. Keeler; R. G. Kellogg; B. W. Kennedy; D. H. Kim; K. Klein; A. Klier; S. Kluth; T. Kobayashi; M. Kobel; T. P. Kokott; S. Komamiya; R. V. Kowalewski; T. Kress; P. Krieger; J. von Krogh; T. Kuhl; M. Kupper; P. Kyberd; G. D. Lafferty; H. Landsman; D. Lanske; I. Lawson; J. G. Layter; A. Leins; D. Lellouch; J. Letts; L. Levinson; R. Liebisch; J. Lillich; B. List; C. Littlewood; A. W. Lloyd; S. L. Lloyd; F. K. Loebinger; G. D. Long; M. J. Losty; J. Lu; J. Ludwig; A. Macchiolo; A. Macpherson; W. Mader; S. Marcellini; T. E. Marchant; A. J. Martin; J. P. Martin; G. Martinez; T. Mashimo; P. Mättig; W. J. McDonald; J. McKenna; T. J. McMahon; R. A. McPherson; F. Meijers; P. Mendez-Lorenzo; W. Menges; F. S. Merritt; H. Mes; A. Michelini; S. Mihara; G. Mikenberg; D. J. Miller; W. Mohr; A. Montanari; T. Mori; K. Nagai; I. Nakamura; H. A. Neal; R. Nisius; S. W. O'Neale; F. G. Oakham; F. Odorici; H. O. Ogren; A. Oh; A. Okpara; M. J. Oreglia; S. Orito; G. Pásztor; J. R. Pater; G. N. Patrick; J. Patt; P. Pfeifenschneider; J. E. Pilcher; J. Pinfold; D. E. Plane; B. Poli; J. Polok; O. Pooth; M. Przybycie?; A. Quadt; C. Rembser; P. Renkel; H. Rick; N. Rodning; J. M. Roney; S. Rosati; K. Roscoe; A. M. Rossi; Y. Rozen; K. Runge; O. Runolfsson; D. R. Rust; K. Sachs; T. Saeki; O. Sahr; E. K. G. Sarkisyan; C. Sbarra; A. D. Schaile; O. Schaile; P. Scharff-Hansen; M. Schröder; M. Schumacher; C. Schwick; W. G. Scott; R. Seuster; T. G. Shears; B. C. Shen; C. H. Shepherd-Themistocleous; P. Sherwood; G. P. Siroli; A. Skuja; A. M. Smith; G. A. Snow; R. Sobie; S. Söldner-Rembold; S. Spagnolo; M. Sproston; A. Stahl; K. Stephens; K. Stoll; D. Strom; R. Ströhmer; L. Stumpf; B. Surrow; S. D. Talbot; S. Tarem; R. J. Taylor; R. Teuscher; M. Thiergen; J. Thomas; M. A. Thomson; E. Torrence; S. Towers; D. Toya; T. Trefzger; I. Trigger; Z. Trócsányi; E. Tsur; M. F. Turner-Watson; I. Ueda; B. Vachon; P. Vannerem; M. Verzocchi; H. Voss; J. Vossebeld; D. Waller; C. P. Ward; D. R. Ward; P. M. Watkins; A. T. Watson; N. K. Watson; P. S. Wells; T. Wengler; N. Wermes; D. Wetterling; J. S. White; G. W. Wilson; J. A. Wilson; T. R. Wyatt; S. Yamashita; V. Zacek; D. Zer-Zion

    2000-01-01

    The lifetime and oscillation frequency of the B0 meson has been measured using B?0?D?+???? decays recorded on the Z0 peak with the OPAL detector at LEP. The D?+?D0?+ decays were reconstructed using an inclusive technique and the production flavour of the B0 mesons was determined using a combination of tags from the rest of the event. The results ?B0=1.541±0.028±0.023ps,?md=0.497±0.024±0.025ps?1 were

  3. Lifetime measurements in neutron-rich 63,65Co isotopes using the AGATA demonstrator

    NASA Astrophysics Data System (ADS)

    Modamio, V.; Valiente-Dobón, J. J.; Lunardi, S.; Lenzi, S. M.; Gadea, A.; Mengoni, D.; Bazzacco, D.; Algora, A.; Bednarczyk, P.; Benzoni, G.; Birkenbach, B.; Bracco, A.; Bruyneel, B.; Bürger, A.; Chavas, J.; Corradi, L.; Crespi, F. C. L.; de Angelis, G.; Désesquelles, P.; de France, G.; Depalo, R.; Dewald, A.; Doncel, M.; Erduran, M. N.; Farnea, E.; Fioretto, E.; Fransen, Ch.; Geibel, K.; Gottardo, A.; Görgen, A.; Habermann, T.; Hackstein, M.; Hess, H.; Hüyük, T.; John, P. R.; Jolie, J.; Judson, D.; Jungclaus, A.; Karkour, N.; Kempley, R.; Leoni, S.; Melon, B.; Menegazzo, R.; Michelagnoli, C.; Mijatovi?, T.; Million, B.; Möller, O.; Montagnoli, G.; Montanari, D.; Nannini, A.; Napoli, D. R.; Podolyak, Zs.; Pollarolo, G.; Pullia, A.; Quintana, B.; Recchia, F.; Reiter, P.; Rosso, D.; Rother, W.; Sahin, E.; Salsac, M. D.; Scarlassara, F.; Sieja, K.; Söderström, P. A.; Stefanini, A. M.; Stezowski, O.; Szilner, S.; Theisen, Ch.; Travers, B.; Ur, C. A.

    2013-10-01

    Lifetimes of the low-lying (11/2-) states in 63,65Co have been measured employing the recoil distance doppler shift method (RDDS) with the AGATA ?-ray array and the PRISMA mass spectrometer. These nuclei were populated via a multinucleon transfer reaction by bombarding a 238U target with a beam of 64Ni. The experimental B(E2) reduced transition probabilities for 63,65Co are well reproduced by large-scale shell-model calculations that predict a constant trend of the B(E2) values up to the N=40 67Co isotope.

  4. Muon Lifetime Measurement and Introduction to the use of FPGAs in Experimental Physics

    NASA Astrophysics Data System (ADS)

    Villaseñor, L.

    2008-07-01

    During the laboratory sessions at the Workshop, the students used a simple experimental setup to measure the muon lifetime with a 10% statistical error. The muon detector consisted of a sealed container, filled with liquid scintillator, coupled to a 2.5? photomultiplier (PMT). A personal computer (PC) was used to control a digital oscilloscope which directly measured the time interval between two consecutive PMT pulses in a time window of 20 ?s. The students were also introduced to the use of root to analyze the muon data and to measure the muon lifetime. They were also presented with a basic introduction to the application of field-programmable gate arrays (FPGAs) in data acquisition (DAQ) systems by means of examples. We started with a brief introduction to the VHDL language and the software package used to program FPGAs and PROMs on a commercial FPGA development board. They learned to program FPGAs for handling data transfers using the RS-232 port of a PC. They were also introduced to the concepts of circular RAMs (Random Access Memory) and FIFO (First-In First-Out) memories in the context of fast and efficient DAQ systems. We emphasized the way in which inexpensive FPGA-based electronics replaces the use of traditionally used electronics modules, such as NIM, CAMAC, FASTBUS, VME, etc., to construct fast and powerful DAQ systems.

  5. A measurement of the lambda_b lifetime at the D0 experiment

    SciTech Connect

    Lewin, Marcus Philip; /Lancaster U.

    2007-07-01

    This thesis describes a measurement of the lifetime of the {Lambda}{sub b}{sup 0} baryon, performed using data from proton-antiproton collisions at a centre of mass energy of 1.96 TeV. The decay {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{mu}{sup -}{ovr P{nu}}{sub {mu}}X was reconstructed in approximately 1.3 fb{sup -1} of data recorded by the D0 detector in 2002-2006 during Run II of the Fermilab Tevatron collider. A signal of 4437 {+-} 329 {Lambda}{sub c}{sup +}{mu}{sup -} pairs was obtained, and the {Lambda}{sub b}{sup 0} lifetime was measured using a binned {chi}{sup 2} fit, which gives a value {tau}({Lambda}{sub b}{sup 0}) = 1.290{sub -0.110}{sup +0.119}(stat){sub -0.091}{sup +0.085}(syst) ps. This result is consistent with the world average and is one of the most precise measurements of this quantity.

  6. Positron Annihilation Spectroscopy Study of Ni-Mn-Ga Ferromagnetic Shape Memory Alloys

    NASA Astrophysics Data System (ADS)

    Merida, David; Garcia, Jose Angel; Apiñaniz, Estibaliz; Plazaola, Fernando; Sanchez-Alarcos, Vicente; Pérez-Landazábal, Jose Ignacio; Recarte, Vicente

    We have studied the role that vacancy type defects play in the martensitic transformation of Ni-Mn-Ga ferromagnetic shape memory alloys by means of positron lifetime spectroscopy. The measurements presented in this work have been performed in five ternary alloys. Three of them transform to modulated and two to non-modulated martensitic phases. With these five samples we cover a large range in composition. Positron experiments have been performed at room temperature after subsequent isochronal annealing at different temperatures and up to a maximum temperature of 600°C. Results show a large variation of the average positron lifetime value with the isochronal annealing temperature in non-modulated samples. However, the response in the modulated samples is quite different. The results are discussed in term of different type of positron trapping defects and their evolution with the annealing temperature. The present work shows a correlation between vacancy concentration and martensitic transformation temperature of ferromagnetic shape memory alloys.

  7. Serotonin modulation of cerebral blood flow measured with positron emission tomography (PET) in humans.

    PubMed

    Geday, Jacob; Hermansen, Flemming; Rosenberg, Raben; Smith, Donald F

    2005-03-15

    To develop a method to measure the dynamic response of the serotonin system in vivo, the effects of intravenously administered citalopram (the most selective of the serotonin reuptake inhibitors) or clomipramine on cerebral blood flow (CBF) were evaluated. CBF was measured with positron emission tomography (PET) in 27 normal subjects scanned under baseline conditions and, on the same day, after an intravenous (IV) infusion of placebo, citalopram, or clomipramine using a randomized, double-blind design. The main effects of the drugs on blood flow occurred in the thalamus, hypothalamus, and cingulate cortex. Compared to placebo, clomipramine reduced blood flow in the mediodorsal and ventral lateral nuclei of the thalamus, whereas citalopram reduced blood flow in the pulvinar nucleus and the hypothalamus. Compared to clomipramine, citalopram decreased blood flow in the cingulate cortex. The findings support previous reports showing acute central effects of citalopram and clomipramine on regional serotonergic functions measured by PET. Acute side effects may, however, require that care is taken in the selection of experimental designs for future PET studies using IV administration of these antidepressants. PMID:15668991

  8. Design of a circuit for measuring the lifetimes of excited nuclear states of the order of nanoseconds

    E-print Network

    Kuritzky, Clarence Samuel

    1964-01-01

    . The time curve ts mathematically evaluated to give the lifetime. iv Chapter TABLE OF CONTENTS Page I. METHODS OF MEASURING SHORT LIfETIMES . . Coulomb Excitation Method . . Nuclear Recoil Method Nuclear Resonance Flourescence Method 'Delayed... between radiaticr s in nanoseconds Figure 10. Delayed and Pr empt Ccincider-ce Curves in Mean Lifetime Measuremer t. Hence and letting y = (t-t') t F(t) = k e e P(y) dy. -kt ( ky Differentiating this result we get = - XF(t) + 1. P (t) = 1 (P (t...

  9. Measurement of the B+- lifetime and top quark identification using secondary vertex b-tagging

    SciTech Connect

    Schwartzman, Ariel G

    2004-02-01

    This dissertation presents a preliminary measurement of the B{sup {+-}} lifetime through the full reconstruction of its decay chain, and the identification of top quark production in the electron plus jets channel using the displaced vertex b-tagging method. Its main contribution is the development, implementation and optimization of the Kalman filter algorithm for vertex reconstruction, and of the displaced vertex technique for tagging jets arising from b quark fragmentation, both of which have now become part of the standard D0 reconstruction package. These two algorithms fully exploit the new state-of-the-art tracking detectors, recently installed as part of the Run 2 D0 upgrade project. The analysis is based on data collected during Run 2a at the Fermilab Tevatron p{bar p} Hadron Collider up to April 2003, corresponding to an integrated luminosity of 60 pb{sup -1}. The measured B meson lifetime of {tau} = 1.57 {+-} 0.18 ps is in agreement with the current world average, with a competitive level of precision expected when the full data sample becomes available.

  10. Positron-rubidium scattering

    NASA Technical Reports Server (NTRS)

    Mceachran, R. P.; Horbatsch, M.; Stauffer, A. D.

    1990-01-01

    A 5-state close-coupling calculation (5s-5p-4d-6s-6p) was carried out for positron-Rb scattering in the energy range 3.7 to 28.0 eV. In contrast to the results of similar close-coupling calculations for positron-Na and positron-K scattering the (effective) total integrated cross section has an energy dependence which is contrary to recent experimental measurements.

  11. Positron annihilation spectroscopy as a probe of microscopic structure and physical aging in polymer

    SciTech Connect

    Yu, M.

    1992-01-01

    Positron annihilation is studied as a characterization method for the properties of polymers. Previous studies indicate that the orthopositronium lifetime [tau][sub 3] and intensity I[sub 3] is correlated to the free volume [open quotes]hole[close quotes] size and number density of holes in a polymer. Positron annihilation lifetime (PAL) studies in polymers measure the change in free volume, and they are sensitive to different physical environments. PAL studies of the temperature dependence of a disphenol-A polycarbonate shows that the free volume increases with increasing temperature, and it also obtains the transition temperatures T[sub g] and T[sub [beta

  12. Excited-Level Lifetimes and Hyperfine-Structure Measurements on Ions using Collinear Laser Ion-Beam Spectroscopy 

    E-print Network

    Jin, J.; Church, David A.

    1994-01-01

    The mean lifetimes tau of the Ca II 4p P-2(1/2) and 4p P-2(3/2) levels, and the Cl-35 II 4p' F-1(3) level, have been measured by a variant of the collinear laser-ion-beam lifetime technique applied previously to the Ar II 4p' F-2(7/2)o level [Jian...

  13. Positron Beam Characteristics at NEPOMUC Upgrade

    NASA Astrophysics Data System (ADS)

    Hugenschmidt, C.; Ceeh, H.; Gigl, T.; Lippert, F.; Piochacz, C.; Reiner, M.; Schreckenbach, K.; Vohburger, S.; Weber, J.; Zimnik, S.

    2014-04-01

    In 2012, the new neutron induced positron source NEPOMUC upgrade was put into operation at FRMII. Major changes have been made to the source which consists of a neutron-?-converter out of Cd and a Pt foil structure for electron positron pair production and positron moderation. The new design leads to an improvement of both intensity and brightness of the mono-energetic positron beam. In addition, the application of highly enriched 113Cd as neutron-?-converter extends the lifetime of the positron source to 25 years. A new switching and remoderation device has been installed in order to allow toggling from the high-intensity primary beam to a brightness enhanced remoderated positron beam. At present, an intensity of more than 109 moderated positrons per second is achieved at NEPOMUC upgrade. The main characteristics are presented which comprise positron yield and beam profile of both the primary and the remoderated positron beam.

  14. A new method for picosecond lifetime measurements using electronic timing: Nuclear structure applications

    SciTech Connect

    Gill, R.L.

    1990-01-01

    A technique to measure the lifetimes of nuclear states with half lives <10 ps has been developed in conjunction with the TRISTAN mass separator at the High Flux Beam Reactor at BNL. The method uses fast plastic and BaF{sub 2} scintillators and Ge detectors in a triple coincidence ({beta}-{gamma}-{gamma}) fast-slow counting system. The timing information is derived from the fast plastic-BaF{sub 2} coincidence, while the higher resolution of the Ge detector (in slow coincidence) serves to insure that the {beta}-{gamma} event lies in the cascade of interest. The calibrations and corrections necessary to achieve precise results and the methods of data reduction and results from recent measurements on the A = 97 mass chain are presented. 11 refs., 7 figs.

  15. Shot noise as a measure of the lifetime and energy splitting of Majorana bound states

    NASA Astrophysics Data System (ADS)

    Lü, Hai-Feng; Guo, Zhen; Ke, Sha-Sha; Guo, Yong; Zhang, Huai-Wu

    2015-04-01

    We propose a scheme to measure the lifetime and energy splitting of a pair of Majorana bound states at the ends of a superconducting nanowire by using the shot noise in a dynamical channel blockade system. A quantum dot is coupled to one end of the wire and connected with two electron reservoirs. It is found that a finite Majorana energy splitting tends to produce a super-Poissonian shot noise, while Majorana relaxation process relieves the dynamical channel blockade and suppresses the noise Fano factor. When the dot energy level locates in the middle of the gap of topological superconductor, the Fano factor is independent on Majorana lifetime and Majorana energy splitting is thus extracted. For a finite energy splitting, we could evaluate the Majorana relaxation rate from the suppression of Fano factor. Under a realistic condition, the expected resolution of Majorana energy splitting and its relaxation rate calculated from our model are about 1 ? eV and 0.01 - 1 ? eV , respectively.

  16. Application of positron annihilation spectroscopy to the characterization of rocks

    NASA Astrophysics Data System (ADS)

    Urban-Klaehn, Jagoda Maria

    1998-11-01

    This work is a first comprehensive study on rocks by use of the positron annihilation methods: Doppler Broadening Spectroscopy (DBS) and the lifetime measurements (LT). The complementary methods like Scanning Electron Microscopy (SEM), the residual gas analysis method (RGAS) and gas absorption (BET) methods were used also. Several rock samples with the known composition and porosity, mainly natural sandstones, carbonates but also anhydrite, opals and synthetic sandstones have been studied. Rocks have been investigated in different states, dry versus soaked (in water, brine or hydrocarbons) and heated (20-220°C) versus non-heated For the rocks with similar structure and porosity, the positron annihilation (PA) signal has been found to depend primarily on the rock composition (S-parameter and the mean lifetime values were higher for sandstones than for carbonates) and on the rock state, but to a lesser extent. We found also how the structural differences affect the PA signal by studying powderized versus non-powderized samples and opals versus sandstones. Our measurements have proved that rocks can be segregated according to their PA- parameter values. The positron annihilation parameters, like S,SW,W-parameters and the mean lifetime values have been found to be characteristic for each rock. Physical models explaining how positron annihilation response is sensitive to the rock composition, structure and state have been developed. We also propose a new analysis method to get more insight into the rock microstructure. In the long perspective, the understanding of the physics of positron interactions in rocks can lead to the development of a new nuclear well-logging tool using the positron annihilation technique, which would characterize the rock and its state uniquely.

  17. Positron annihilation study on hafnium metals given various treatments

    SciTech Connect

    Min, Duck Ki; Kang, Myung Soo (Korea Atomic Energy Research Inst., Taejon (Korea, Republic of)); Yoon, Young Ku (Korea Advanced Inst. of Science and Tech., Taejon (Korea, Republic of))

    1993-08-01

    The positron annihilation technique that enables measurements of positron lifetime, two-photon angular correlation and Doppler broadening due to annihilation radiation has been established for studies of the electronic configuration and defect properties in solids. In metals, positrons can be trapped at vacancies and their agglomerates as well as at dislocations, but not at interstitials. Because of these interactions, the positron annihilation method can be applied to studies of the behavior of dislocations during annealing of plastically deformed metals. Furthermore, it is possible by measurements of annihilation characteristics to identify defects such as vacancies, dislocations and vacancy-clusters, and to determine spatial dimensions of defects. In this work, positron annihilation measurements for annealed, cold worked, annealed and then quenched, and cold worked and then cathodically hydrogen charged hafnium specimens were made to obtain information on (a) positron annihilation characteristics of hafnium metal, (b) role of vacancy-type defects on hydrogen charging, (c) defects produced during hydrogen charging and (d) recovery of lattice defects in hafnium and effects of hydrogen on defects recovery upon annealing.

  18. Measurement of positron reemission from thin single-crystal W(100) films

    Microsoft Academic Search

    D. M. Chen; K. G. Lynn; R. Pareja; Bent Nielsen

    1985-01-01

    Epitaxial thin single-crystal (100) tungsten films 1000, 2500, and 5000 Å thick have been fabricated by high-vacuum electron-beam evaporation. These films were subsequently used as thin-film moderators for the study of the positron-transmission-reemission process with a variable-energy (0-80 keV) monoenergetic positron beam in an ultrahigh-vacuum system. The films were shown to be routinely cleanable by heating first in oxygen (10-6

  19. Measurement of positron reemission from thin single-crystal W(100) films

    Microsoft Academic Search

    D. M. Chen; K. G. Lynn; R. Pareja; Bent Nielsen

    1985-01-01

    Epitaxial thin single-crystal (100) tungsten films 1000, 2500, and 5000 A thick have been fabricated by high-vacuum electron-beam evaporation. These films were subsequently used as thin-film moderators for the study of the positron-transmission-reemission process with a variable-energy (0--80 keV) monoenergetic positron beam in an ultrahigh-vacuum system. The films were shown to be routinely cleanable by heating first in oxygen (10⁻⁶

  20. Method of determining metal contamination by combining p-type Si and n-type Si recombination lifetime measurements

    NASA Astrophysics Data System (ADS)

    Itsumi, Manabu

    1993-08-01

    A method is proposed for determining heavy-metal impurities by combining p-type Si and n-type Si recombination lifetime measurements. The experimental results show three trends in the relationships between p-type Si lifetime and n-type Si lifetime depending on the heavy-metal impurities. One trend is related to iron (I line), another is to copper (C line), and the other is to stainless-steel components (S line: iron and nickel). These three trends are used to estimate the unknown metallic impurities. Several examples are shown to demonstrate the advantages of this method. It is also shown that lifetime data associated with plasma processes are distributed near the S line. This method is convenient for monitoring and reducing metallic contamination levels.

  1. Measurement of heritability of myocardial blood flow by positron emission tomography: the Twins Heart Study

    PubMed Central

    Su, Shaoyong; Votaw, John; Faber, Tracy; Khan, Durreshahwar; Bremner, J Douglas; Goldberg, Jack; Nichols, Ken; Van Tosh, Andrew; Vaccarino, Viola

    2015-01-01

    Objective To estimate the heritability of myocardial blood flow (MBF) and coronary flow reserve (CFR) measured with positron emission tomography (PET). Design Cross-sectional twin study. Setting General clinical research centre of a university hospital at Atlanta, USA. Patients A sample of 180 middle-aged (mean±SD 55±2.9 years) male twins, including 107 monozygotic and 73 dizygotic twins. Main outcome measures All twins underwent imaging of MBF with PET 13NH3 at rest and after adenosine stress during a single imaging session. Structural equation modelling was used to estimate the heritability of MBF at rest and during adenosine stress, as well as of CFR. Results The basal MBF (mean±SD) was 0.69±0.20 ml/min/g, and the MBF during adenosine stress was 1.70±0.49 ml/min/g; the CFR was 2.62±0.99. There was substantial heritability for MBF both at rest (0.48, 95% CI 0.29 to 0.64) and during adenosine stress (0.51, 95% CI 0.29 to 0.68), as well as CFR (0.48, 95% CI 0.26 to 0.65). Conclusions For the first time, a substantial genetic contribution to the interindividual variation in MBF and CFR measured with PET in middle-aged men has been demonstrated. The data suggest that a fruitful direction for future work would be the identification of genetic variants for early atherosclerotic stages assessed by PET imaging. PMID:22323242

  2. Positron annihilation in flight: experiment with slow and fast positrons

    NASA Astrophysics Data System (ADS)

    ?ížek, J.; Vl?ek, M.; Luká?, F.; Melikhova, O.; Procházka, I.; Anwand, W.; Wagner, A.; Butterling, M.; Krause-Rehberg, R.

    2014-04-01

    A novel digital coincidence Doppler broadening (D-CDB) spectrometer was employed for energy resolved investigations of two-quantum annihilation-in-flight (TQAF). The TQAF phenomenon was studied using monoenergetic positrons produced in a slow positron beam and also using fast positrons. Because of a low background the measurements on the slow positron beam could be performed in a close geometry and the TQAF contribution in the two-dimensional gamma ray energy spectra fills a 'bowl-like' area delimited by a hyperbolic curve and a kinematical cut-off determined by the kinetic energy of positrons. With decreasing positron energy the area of TQAF contribution becomes smaller and disappears completely for slow positrons with energies below ~ 100 eV. The measurements with fast positrons were restricted to a limited range of angles between the annihilation gamma rays and the TQAF events contribute to a hyperbolic band in gamma ray energy spectrum.

  3. Measuring protein interactions using Förster resonance energy transfer and fluorescence lifetime imaging microscopy.

    PubMed

    Day, Richard N

    2014-03-15

    The method of fluorescence lifetime imaging microscopy (FLIM) is a quantitative approach that can be used to detect Förster resonance energy transfer (FRET). The use of FLIM to measure the FRET that results from the interactions between proteins labeled with fluorescent proteins (FPs) inside living cells provides a non-invasive method for mapping interactomes. Here, the use of the phasor plot method to analyze frequency domain (FD) FLIM measurements is described, and measurements obtained from cells producing the 'FRET standard' fusion proteins are used to validate the FLIM system for FRET measurements. The FLIM FRET approach is then used to measure both homologous and heterologous protein-protein interactions (PPI) involving the CCAAT/enhancer-binding protein alpha (C/EBP?). C/EBP? is a transcription factor that controls cell differentiation, and localizes to heterochromatin where it interacts with the heterochromatin protein 1 alpha (HP1?). The FLIM-FRET method is used to quantify the homologous interactions between the FP-labeled basic leucine zipper (BZip) domain of C/EBP?. Then the heterologous interactions between the C/EBPa BZip domain and HP1a are quantified using the FRET-FLIM method. The results demonstrate that the basic region and leucine zipper (BZip) domain of C/EBP? is sufficient for the interaction with HP1? in regions of heterochromatin. PMID:23806643

  4. Measurement of high-Q^2 deep inelastic scattering cross sections with a longitudinally polarised positron beam at HERA

    E-print Network

    ZEUS Collaboration

    2006-04-20

    The cross sections for charged and neutral current deep inelastic scattering in e^+p collisions with a longitudinally polarised positron beam have been measured using the ZEUS detector at HERA. The results, based on data corresponding to an integrated luminosity of 23.8 pb^-1 at sqrt(s) = 318 GeV, are given for both e^+p charged current and neutral current deep inelastic scattering for both positive and negative values of the longitudinal polarisation of the positron beam. Single differential cross sections are presented for the kinematic region Q^2 > 200 GeV^2 . The measured cross sections are compared to the predictions of the Standard Model. A fit to the data yields sigma^CC (P_e = -1) = 7.4 +/- 3.9 (stat.) +/- 1.2 (syst.) pb, which is consistent within two standard deviations with the absence of right-handed charged currents in the Standard Model.

  5. Measurement of high-Q deep inelastic scattering cross sections with a longitudinally polarised positron beam at HERA

    NASA Astrophysics Data System (ADS)

    ZEUS Collaboration; Chekanov, S.; Derrick, M.; Magill, S.; Miglioranzi, S.; Musgrave, B.; Nicholass, D.; Repond, J.; Yoshida, R.; Mattingly, M. C. K.; Pavel, N.; Yagües Molina, A. G.; Antonelli, S.; Antonioli, P.; Bari, G.; Basile, M.; Bellagamba, L.; Bindi, M.; Boscherini, D.; Bruni, A.; Bruni, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; de Pasquale, S.; Iacobucci, G.; Margotti, A.; Nania, R.; Polini, A.; Rinaldi, L.; Sartorelli, G.; Zichichi, A.; Aghuzumtsyan, G.; Bartsch, D.; Brock, I.; Goers, S.; Hartmann, H.; Hilger, E.; Jakob, H.-P.; Jüngst, M.; Kind, O. M.; Paul, E.; Rautenberg, J.; Renner, R.; Samson, U.; Schönberg, V.; Wang, M.; Wlasenko, M.; Brook, N. H.; Heath, G. P.; Morris, J. D.; Namsoo, T.; Capua, M.; Fazio, S.; Mastroberardino, A.; Schioppa, M.; Susinno, G.; Tassi, E.; Kim, J. Y.; Ma, K. J.; Ibrahim, Z. A.; Kamaluddin, B.; Wan Abdullah, W. A. T.; Ning, Y.; Ren, Z.; Schmidke, W. B.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Galas, A.; Gil, M.; Olkiewicz, K.; Stopa, P.; Zawiejski, L.; Adamczyk, L.; Bo?d, T.; Grabowska-Bo?d, I.; Kisielewska, D.; ?ukasik, J.; Przybycie?, M.; Suszycki, L.; Kota?ski, A.; S?omi?ski, W.; Adler, V.; Behrens, U.; Bloch, I.; Bonato, A.; Borras, K.; Coppola, N.; Fourletova, J.; Geiser, A.; Gladkov, D.; Göttlicher, P.; Gregor, I.; Gutsche, O.; Haas, T.; Hain, W.; Horn, C.; Kahle, B.; Kötz, U.; Kowalski, H.; Lim, H.; Lobodzinska, E.; Löhr, B.; Mankel, R.; Melzer-Pellmann, I.-A.; Montanari, A.; Nguyen, C. N.; Notz, D.; Nuncio-Quiroz, A. E.; Santamarta, R.; Schneekloth, U.; Stadie, H.; Stösslein, U.; Szuba, D.; Szuba, J.; Theedt, T.; Watt, G.; Wolf, G.; Wrona, K.; Youngman, C.; Zeuner, W.; Schlenstedt, S.; Barbagli, G.; Gallo, E.; Pelfer, P. G.; Bamberger, A.; Benen, A.; Dobur, D.; Karstens, F.; Vlasov, N. N.; Bussey, P. J.; Doyle, A. T.; Dunne, W.; Ferrando, J.; Saxon, D. H.; Skillicorn, I. O.; Gialas, I.; Gosau, T.; Holm, U.; Klanner, R.; Lohrmann, E.; Salehi, H.; Schleper, P.; Schörner-Sadenius, T.; Sztuk, J.; Wichmann, K.; Wick, K.; Foudas, C.; Fry, C.; Long, K. R.; Tapper, A. D.; Kataoka, M.; Nagano, K.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Barakbaev, A. N.; Boos, E. G.; Dossanov, A.; Pokrovskiy, N. S.; Zhautykov, B. O.; Son, D.; de Favereau, J.; Piotrzkowski, K.; Barreiro, F.; Glasman, C.; Jimenez, M.; Labarga, L.; Del Peso, J.; Ron, E.; Terrón, J.; Zambrana, M.; Corriveau, F.; Liu, C.; Walsh, R.; Zhou, C.; Tsurugai, T.; Antonov, A.; Dolgoshein, B. A.; Rubinsky, I.; Sosnovtsev, V.; Stifutkin, A.; Suchkov, S.; Dementiev, R. K.; Ermolov, P. F.; Gladilin, L. K.; Katkov, I. I.; Khein, L. A.; Korzhavina, I. A.; Kuzmin, V. A.; Levchenko, B. B.; Lukina, O. Yu.; Proskuryakov, A. S.; Shcheglova, L. M.; Zotkin, D. S.; Zotkin, S. A.; Abt, I.; Büttner, C.; Caldwell, A.; Kollar, D.; Liu, X.; Sutiak, J.; Grigorescu, G.; Keramidas, A.; Koffeman, E.; Kooijman, P.; Maddox, E.; Tiecke, H.; Vázquez, M.; Wiggers, L.; Brümmer, N.; Bylsma, B.; Durkin, L. S.; Lee, A.; Ling, T. Y.; Allfrey, P. D.; Bell, M. A.; Cooper-Sarkar, A. M.; Cottrell, A.; Devenish, R. C. E.; Foster, B.; Gwenlan, C.; Korcsak-Gorzo, K.; Patel, S.; Roberfroid, V.; Robertson, A.; Straub, P. B.; Uribe-Estrada, C.; Walczak, R.; Bellan, P.; Bertolin, A.; Brugnera, R.; Carlin, R.; Ciesielski, R.; Dal Corso, F.; Dusini, S.; Garfagnini, A.; Limentani, S.; Longhin, A.; Stanco, L.; Turcato, M.; Oh, B. Y.; Raval, A.; Whitmore, J. J.; Iga, Y.; D'Agostini, G.; Marini, G.; Nigro, A.; Cole, J. E.; Hart, J. C.; Abramowicz, H.; Gabareen, A.; Kananov, S.; Levy, A.; Kuze, M.; Hori, R.; Kagawa, S.; Shimizu, S.; Tawara, T.; Hamatsu, R.; Kaji, H.; Kitamura, S.; Ota, O.; Ri, Y. D.; Ferrero, M. I.; Monaco, V.; Sacchi, R.; Solano, A.; Staiano, A.; Arneodo, M.; Ruspa, M.; Fourletov, S.; Martin, J. F.; Butterworth, J. M.; Hall-Wilton, R.; Jones, T. W.; Loizides, J. H.; Sutton, M. R.; Targett-Adams, C.; Wing, M.; Brzozowska, B.; Ciborowski, J.; Grzelak, G.; Kulinski, P.; ?u?niak, P.; Malka, J.; Nowak, R. J.; Pawlak, J. M.; Tymieniecka, T.; Ukleja, A.; Ukleja, J.; Zarnecki, A. F.; Adamus, M.; Plucinski, P.; Eisenberg, Y.; Hochman, D.; Karshon, U.; Brownson, E.; Danielson, T.; Everett, A.; Kçira, D.; Reeder, D. D.; Rosin, M.; Ryan, P.; Savin, A. A.; Smith, W. H.; Wolfe, H.; Bhadra, S.; Catterall, C. D.; Cui, Y.; Hartner, G.; Menary, S.; Noor, U.; Soares, M.; Standage, J.; Whyte, J.

    2006-06-01

    The cross sections for charged and neutral current deep inelastic scattering in ep collisions with a longitudinally polarised positron beam have been measured using the ZEUS detector at HERA. The results, based on data corresponding to an integrated luminosity of 23.8 pb-1 at s=318 GeV, are given for both ep charged current and neutral current deep inelastic scattering for both positive and negative values of the longitudinal polarisation of the positron beam. Single differential cross sections are presented for the kinematic region Q>200 GeV. The measured cross sections are compared to the predictions of the Standard Model. A fit to the data yields ?(P=-1)=7.4±3.9(stat.)±1.2(syst.) pb, which is consistent within two standard deviations with the absence of right-handed charged currents in the Standard Model.

  6. Positrons from supernovae

    NASA Technical Reports Server (NTRS)

    Chan, Kai-Wing; Lingenfelter, Richard E.

    1993-01-01

    Positrons are produced in the ejecta of supernovae by the decay of nucleosynthetic Co-56, Ti-44, and Al-26. We calculate the probability that these positrons can survive without annihilating in the supernova ejecta, and we show that enough of these positrons should escape into the interstellar medium to account for the observed diffuse Galactic annihilation radiation. The surviving positrons are carried by the expanding ejecta into the interstellar medium where their annihilation lifetime of 10 exp 5 - 10 exp 6 yr is much longer than the average supernovae occurrence time of about 100 yr. Thus, annihilating positrons from thousands of supernovae throughout the Galaxy produce a steady diffuse flux of annihilation radiation. We further show that combining the calculated positron survival fractions and nucleosynthetic yields for current supernova models with the estimated supernova rates and the observed flux of diffuse Galactic annihilation radiation suggests that the present Galactic rate of Fe-56 nucleosynthesis is about 0.8 +/- 0.6 solar mass per 100 yr.

  7. Lifetime measurements of yrast states in {sup 162}Yb and {sup 166}Hf

    SciTech Connect

    McCutchan, E.A.; Casten, R.F.; Ai, H.; Amro, H.; Heinz, A.; Meyer, D.A.; Plettner, C.; Qian, J.; Ressler, J.J.; Werner, V.; Williams, E.; Winkler, R. [Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States); Zamfir, N.V. [Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States); National Institute of Physics and Nuclear Engineering, Bucharest-Magurele (Romania); Babilon, M. [Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States); Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 (Germany); Brenner, D.S. [Clark University, Worcester, Massachusetts 01610 (United States); Guerdal, G. [Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States); Clark University, Worcester, Massachusetts 01610 (United States); Hughes, R.O.; Thomas, N.J. [Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States); University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2006-03-15

    Lifetime measurements of yrast levels in {sup 162}Yb and {sup 166}Hf were performed using the recoil distance Doppler-shift method in coincidence mode. Excited states in {sup 162}Yb and {sup 166}Hf were populated via the reactions {sup 116}Cd({sup 50}Ti, 4n) and {sup 122}Sn({sup 48}Ti, 4n), respectively. The resulting B(E2) values are compared with the X(5) critical point model predictions and interacting boson approximation (IBA) model calculations. The X(5) model provides a reasonable description of the yrast B(E2) values in {sup 166}Hf, whereas the IBA fails to reproduce the transition strengths from the higher spin levels. In {sup 162}Yb, some transitions agree with the X(5) predictions while others are more consistent with the predictions of the IBA or a deformed symmetric rotor.

  8. Lifetime Measurement of the 2{sup +}{sub 1} state in {sup 20}C

    SciTech Connect

    Petri, Marina-Kalliopi; Fallon, Paul; Macchiavelli, Augusto; Paschalis, Stephanos; Starosta, Krzysztof; Baugher, Travis; Bazin, Daniel; Cartegni, Lucia; Clark, Roderick; Crawford, Heather; Cromaz, Mario; Dewald, Alfred; Gade, Alexandra; Grinyer, Geoff; Gros, Sebastian; Hackstein, Matthias; Jeppesen, Hendrick; Lee, I-Yang; McDaniel, Sean; Miller, Doug; Rajabali, Mustafa; Ratkiewicz, Andrew; Rother, Wolfram; Voss, Phillip; Walsh, Kathleen Ann; Weisshaar, Dirk; Wiedeking, Mathis; Brown, Boyd Alex

    2011-06-28

    Establishing how and when large N/Z values require modified or new theoretical tools is a major quest in nuclear physics. Here we report the first measurement of the lifetime of the 2{sup +}{sub 1} state in the near-dripline nucleus {sup 20}C. The deduced value of {tau}{sub #28;2{sup +}{sub 1}} = 9.8 ± 2.8(stat){sup +0.5}{sub ?1.1}(syst) ps gives a reduced transition probability of B(E2;2{sup +}{sub 1}{yields}0{sup +}{sub g.s.}) = 7.5{sup +3.0}{sub ?1.7}(stat){sup +1.0}{sub ?0.4}(syst) e{sup 2}fm{sup 4} in good agreement with a shell model calculation using isospin-dependent effective charges.

  9. Characterization of a-Si:H/c-Si interfaces by effective-lifetime measurements

    NASA Astrophysics Data System (ADS)

    Garín, M.; Rau, U.; Brendle, W.; Martín, I.; Alcubilla, R.

    2005-11-01

    This article studies theoretically and experimentally the recombination at the amorphous/crystalline silicon interface of a heterojunction with intrinsic thin layer (HIT) structure without metallization. We propose a physical model to calculate the interface recombination rate under illumination. This model calculates the effective lifetime ?eff as a function of the average excess minority carrier concentration . In order to test the model, we prepared a set of HIT structures. The dependence of ?eff vs of the samples is measured using the quasi-steady-state photoconductance technique. By fitting our model to the experimental data, we determine the a-Si:H/c-Si interface parameters and the doping density of the amorphous layer.

  10. Lifetime measurements of 214Po and 212Po with the CTF liquid scintillator detector at LNGS

    E-print Network

    Borexino Collaboration; G. Bellini; J. Benziger; D. Bick; G. Bonfini; D. Bravo; M. Buizza Avanzini; B. Caccianiga; L. Cadonati; F. Calaprice; C. Carraro; P. Cavalcante; A. Chavarria; A. Chepurnov; V. Chubakov; D. D'Angelo; S. Davini; A. Derbin; A. Etenko; K. Fomenko; D. Franco; C. Galbiati; S. Gazzana; C. Ghiano; M. Giammarchi; M. Göger-Neff; A. Goretti; L. Grandi; E. Guardincerri; S. Hardy; Aldo Ianni; Andrea Ianni; V. Kobychev; D. Korablev; G. Korga; Y. Koshio; D. Kryn; M. Laubenstein; T. Lewke; Marcello Lissia; E. Litvinovich; B. Loer; F. Lombardi; P. Lombardi; L. Ludhova; I. Machulin; S. Manecki; W. Maneschg; G. Manuzio; Q. Meindl; E. Meroni; L. Miramonti; M. Misiaszek; D. Montanari; P. Mosteiro; F. Mantovani; V. Muratova; S. Nisi; L. Oberauer; M. Obolensky; F. Ortica; K. Otis; M. Pallavicini; L. Papp; L. Perasso; S. Perasso; A. Pocar; G. Ranucci; A. Razeto; A. Re; A. Romani; N. Rossi; A. Sabelnikov; R. Saldanha; C. Salvo; S. Schönert; H. Simgen; M. Skorokhvatov; O. Smirnov; A. Sotnikov; S. Sukhotin; Y. Suvorov; R. Tartaglia; G. Testera; R. B. Vogelaar; F. von Feilitzsch; J. Winter; M. Wojcik; A. Wright; M. Wurm; G. Xhixha; J. Xu; O. Zaimidoroga; S. Zavatarelli; G. Zuzel

    2013-07-05

    We have studied the alpha decays of 214Po into 210Pb and of 212Po into 208Pb tagged by the coincidence with the preceding beta decays from 214Bi and 212Bi, respectively. The employed 222Rn, 232Th, and 220Rn sources were sealed inside quartz vials and inserted in the Counting Test Facility at the underground Gran Sasso National Laboratory in Italy. We find that the mean lifetime of 214Po is (236.00 +- 0.42(stat) +- 0.15(syst)) \\mu s and that of 212Po is (425.1 +- 0.9(stat) +- 1.2(syst)) ns. Our results, obtained from data with signal-to-background ratio larger than 1000, reduce the overall uncertainties and are compatible with previous measurements.

  11. Measurement of the Bs0 Lifetime in the Flavor-Specific Decay Channel Bs0?Ds-?+? X

    NASA Astrophysics Data System (ADS)

    Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Agnew, J. P.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Borysova, M.; Brandt, A.; Brandt, O.; Brock, R.; Bross, A.; Brown, D.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Pérez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duperrin, A.; Dutt, S.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, V. N.; Fauré, A.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garbincius, P. H.; Garcia-Bellido, A.; García-González, J. A.; Gavrilov, V.; Geng, W.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Gogota, O.; Golovanov, G.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hogan, J.; Hohlfeld, M.; Holzbauer, J. L.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jayasinghe, A.; Jeong, M. S.; Jesik, R.; Jiang, P.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kajfasz, E.; Karmanov, D.; Katsanos, I.; Kaur, M.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kumar, A.; Kupco, A.; Kur?a, T.; Kuzmin, V. A.; Lammers, S.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lei, X.; Lellouch, J.; Li, D.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Mansour, J.; Martínez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Mulhearn, M.; Nagy, E.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nguyen, H. T.; Nunnemann, T.; Orduna, J.; Osman, N.; Osta, J.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Pleier, M.-A.; Podstavkov, V. M.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Ratoff, P. N.; Razumov, I.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Sánchez-Hernández, A.; Sanders, M. P.; Santos, A. S.; Savage, G.; Savitskyi, M.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shaw, S.; Shchukin, A. A.; Simak, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.; Stoyanova, D. A.; Strauss, M.; Suter, L.; Svoisky, P.; Titov, M.; Tokmenin, V. V.; Tsai, Y.-T.; Tsybychev, D.; Tuchming, B.; Tully, C.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.; van Leeuwen, W. M.; Varelas, N.; Varnes, E. W.; Vasilyev, I. A.; Verkheev, A. Y.; Vertogradov, L. S.; Verzocchi, M.; Vesterinen, M.; Vilanova, D.; Vokac, P.; Wahl, H. D.; Wang, M. H. L. S.; Warchol, J.; Watts, G.; Wayne, M.; Weichert, J.; Welty-Rieger, L.; Williams, M. R. J.; Wilson, G. W.; Wobisch, M.; Wood, D. R.; Wyatt, T. R.; Xie, Y.; Yamada, R.; Yang, S.; Yasuda, T.; Yatsunenko, Y. A.; Ye, W.; Ye, Z.; Yin, H.

    2015-02-01

    We present an updated measurement of the Bs0 lifetime using the semileptonic decays Bs0?Ds-?+? X , with Ds-?? ?- and ? ?K+K- (and the charge conjugate process). This measurement uses the full Tevatron Run II sample of proton-antiproton collisions at ?{s }=1.96 TeV , comprising an integrated luminosity of 10.4 fb-1 . We find a flavor-specific lifetime ?fs(Bs0)=1.479 ±0.010 (stat)±0.021 (syst) ps . This technique is also used to determine the B0 lifetime using the analogous B0?D-?+? X decay with D-?? ?- and ? ?K+K-, yielding ? (B0)=1.534 ±0.019 (stat)±0.021 (syst) ps . Both measurements are consistent with the current world averages, and the Bs0 lifetime measurement is one of the most precise to date. Taking advantage of the cancellation of systematic uncertainties, we determine the lifetime ratio ?fs(Bs0)/? (B0)=0.964 ±0.013 (stat)±0.007 (syst) .

  12. Measurement of the bottom hadron lifetime at the Z{sup 0} resonancce

    SciTech Connect

    Fujino, D.H.

    1992-06-01

    We have measured the bottom hadron lifetime from b{bar b} events produced at the Z{sup 0} resonance. Using the precision vertex detectors of the Mark II detector at the Stanford Linear Collider, we developed an impact parameter tag to identify bottom hadrons. The vertex tracking system resolved impact parameters to 30 {mu}m for high momentum tracks, and 70 {mu}m for tracks with a momentum of 1 GeV. We selected B hadrons with an efficiency of 40% and a sample purity of 80%, by requiring there be at least two tracks in a single jet that significantly miss the Z{sup 0} decay vertex. From a total of 208 hadronic Z{sup 0} events collected by the Mark II detector in 1990, we tagged 53 jets, of which 22 came from 11 double-tagged events. The jets opposite the tagged ones, referred as the ``untagged`` sample, are rich in B hadrons and unbiased in B decay times. The variable {Sigma}{delta} is the sum of impact parameters from tracks in the jet, and contains vital information on the B decay time. We measured the B lifetime from a one-parameter likelihood fit to the untagged {Sigma}{delta} distribution, obtaining {tau}{sub b} = 1.53{sub {minus}0.45}{sup +0.55}{plus_minus}0.16 ps which agrees with the current world average. The first error is statistical and the second is systematic. The systematic error was dominated by uncertainties in the track resolution function. As a check, we also obtained consistent results using the {Sigma}{delta} distribution from the tagged jets and from the entire hadronic sample without any bottom enrichment.

  13. Measurement of the bottom hadron lifetime at the Z sup 0 resonancce

    SciTech Connect

    Fujino, D.H.

    1992-06-01

    We have measured the bottom hadron lifetime from b{bar b} events produced at the Z{sup 0} resonance. Using the precision vertex detectors of the Mark II detector at the Stanford Linear Collider, we developed an impact parameter tag to identify bottom hadrons. The vertex tracking system resolved impact parameters to 30 {mu}m for high momentum tracks, and 70 {mu}m for tracks with a momentum of 1 GeV. We selected B hadrons with an efficiency of 40% and a sample purity of 80%, by requiring there be at least two tracks in a single jet that significantly miss the Z{sup 0} decay vertex. From a total of 208 hadronic Z{sup 0} events collected by the Mark II detector in 1990, we tagged 53 jets, of which 22 came from 11 double-tagged events. The jets opposite the tagged ones, referred as the untagged'' sample, are rich in B hadrons and unbiased in B decay times. The variable {Sigma}{delta} is the sum of impact parameters from tracks in the jet, and contains vital information on the B decay time. We measured the B lifetime from a one-parameter likelihood fit to the untagged {Sigma}{delta} distribution, obtaining {tau}{sub b} = 1.53{sub {minus}0.45}{sup +0.55}{plus minus}0.16 ps which agrees with the current world average. The first error is statistical and the second is systematic. The systematic error was dominated by uncertainties in the track resolution function. As a check, we also obtained consistent results using the {Sigma}{delta} distribution from the tagged jets and from the entire hadronic sample without any bottom enrichment.

  14. An acute effect of triazolam on muscarinic cholinergic receptor binding in the human brain measured by positron emission tomography

    Microsoft Academic Search

    Tetsuya Suhara; Osamu Inoue; Kaoru Kobayashi; Toshiyuki Satoh; Yukio Tateno

    1994-01-01

    An acute effect of triazolam, a potent benzodiazepine agonist, on cholinergic receptor binding in the human brain was measured by PET (positron emission tomography) using [11C]N-methyl-4-piperidylbenzilate ([11C]NMPB), a potent muscarinic cholinergic receptor antagonist. Two PET scans were performed in each subject: (1) control scan; (2) after oral administration of 0.5 mg triazolam or placebo. The previously discussed amnestic effect of

  15. Data Analysis for the Measurement of High Energy Cosmic Ray Electron\\/Positron Spectrum with Fermi-LAT

    Microsoft Academic Search

    M. N. Mazziotta

    2009-01-01

    The Large Area Telescope (LAT) instrument on board the Fermi satellite consists of a multi-layer silicon-strip tracker interleaved with tungsten converters (TKR), followed by a CsI crystal hodoscopic calorimeter (CAL). Sixteen TKR and CAL modules are assembled in a 4$\\\\times$4 array. A segmented anticoincidence plastic scintillator (ACD) surrounds the TKRs. The primary cosmic-ray electron\\/positron energy spectrum has been measured from

  16. On possible interpretations of the high energy electron–positron spectrum measured by the Fermi Large Area Telescope

    Microsoft Academic Search

    D. Grasso; S. Profumo; A. W. Strong; L. Baldini; R. Bellazzini; E. D. Bloom; J. Bregeon; G. Di Bernardo; D. Gaggero; N. Giglietto; T. Kamae; L. Latronico; F. Longo; M. N. Mazziotta; A. A. Moiseev; A. Morselli; J. F. Ormes; M. Pesce-Rollins; M. Pohl; M. Razzano; C. Sgro; G. Spandre; T. E. Stephens

    2009-01-01

    The Fermi-LAT experiment recently reported high precision measurements of the spectrum of cosmic-ray electrons-plus-positrons (CRE) between 20GeV and 1TeV. The spectrum shows no prominent spectral features, and is significantly harder than that inferred from several previous experiments. Here we discuss several interpretations of the Fermi results based either on a single large scale Galactic CRE component or by invoking additional

  17. On Possible Interpretations of the High Energy Electron-Positron Spectrum Measured by the Fermi Large Area Telescope

    Microsoft Academic Search

    D. Grasso; S. Profumo; A. W. Strong; L. Baldini; R. Bellazzini; E. D. Bloom; J. Bregeon; G. Di Bernardo; D. Gaggero; N. Giglietto; T. Kamae; L. Latronico; F. Longo; M. N. Mazziotta; A. A. Moiseev; A. Morselli; J. F. Ormes; M. Pesce-Rollins; M. Pohl; M. Razzano; C. Sgro

    2009-01-01

    The Fermi-LAT experiment recently reported high precision measurements of the spectrum of cosmic-ray electrons-plus-positrons (CRE) between 20 GeV and 1 TeV. The spectrum shows no prominent spectral features, and is significantly harder than that inferred from several previous experiments. Here we discuss several interpretations of the Fermi results based either on a single large scale Galactic CRE component or by

  18. On possible interpretations of the high energy electron+positron spectrum measured by the Fermi-LAT

    Microsoft Academic Search

    Daniele Gaggero

    2010-01-01

    The Fermi-LAT collaboration recently published a very accurate measurement of the spectrum of CR electrons+positrons from 20 GeV to 1 TeV. The reported spectrum doesn't show any prominent spectral feature, and - if systematic errors are accounted for - is consistent with a power law whose index is harder than inferred from previous experimental results. We show that the interpretation

  19. Measurements and calculations of metastable level lifetimes in Fe X, Fe XI, Fe XII, Fe XIII, and Fe XIV

    E-print Network

    Moehs, D. P.; Bhatti, M. I.; Church, David A.

    2001-01-01

    Lifetimes of metastable levels in the ground term of Fe ions within the 3s(2)3p(k), k=1-5, isoelectronic sequences have been measured. These measurements were performed utilizing ions that were selected by mass to charge ratio while transported from...

  20. The recovery of electron irradiated zinc and cadmium by positron annihilation spectroscopy

    Microsoft Academic Search

    C. Hidalgo; N. de Diego; P. Moser

    1986-01-01

    Positron lifetime and Doppler-broadening measurements have been performed in Zn and Cd specimens irradiated with 3 MeV electrons at 20 K. Isochronal annealing of the irradiation induced defects between 20 and 280 K has been studied. No evidence of three-dimensional vacancy agglomerates was found.

  1. High sensitivity of positron annihilation to thermal oxidation of polyethylene

    NASA Astrophysics Data System (ADS)

    Ito, Kenji; Kobayashi, Yoshinori; Nanasawa, Atsushi

    2003-01-01

    We demonstrate the high sensitivity of positron annihilation to compositional changes related to the thermal degradation of polyethylene (PE). Positron annihilation ?-ray and lifetime measurements were conducted for PE films with and without antioxidant (1000-ppm Ciba® IRGANOX® 1076), subjected to heat treatment at 100 °C for different periods, to a maximum of 30 days. For the film without antioxidant, the positron Doppler parameter (S) and ortho-positronium formation probability (Io-Ps) appreciably decreased with increased heat treatment times, whereas they barely changed for the film with antioxidant. This, together with the Fourier transform infrared measurements, demonstrated that the variations of S and Io-Ps are caused by the thermal oxidation of PE. The S parameter was found to be sensitive to the early stage of degradation, where the carbonyl concentration is inferred to be lower than 100 ppm. The high sensitivity results from the large positron mobility in PE and from the high positron affinity of oxygen-containing polar groups. This work provides the basis for an application of positron annihilation to sensitive detection of the initial degradation of PE and other nonpolar polymers.

  2. Positron annihilation in superconducting 123 compounds

    SciTech Connect

    Peter, M.; Manuel, A.A.; Erb, A. (Univ. of Geneva (Switzerland). Dept. of Physics of Condensed Matter)

    1998-12-20

    After a brief review of the theory of angular correlation of positron annihilation radiation (ACAR), the authors illustrate experimental principles and give examples of successful determination of electron momentum density (EMD) and of positron lifetime in solids. The central question which the authors try to answer concerns the contribution of positron spectroscopy to the knowledge and understanding of the new high temperature superconducting oxides. They find that in these oxides also, partially filled bands exist and they can observe parts of their Fermi surface and measure lifetimes in accordance with band theoretical calculations. There are characteristic differences, however. The intensity of the anisotropy of the ACAR signal is below theoretical expectation and signals depend on sample preparation. Recent studies by the Geneva group have concerned dependence of the signals on impurities, on oxygen content and on the thermal history of preparation. Of particular interest are correlations between the variations of these signals and between the variations of structural and transport properties in these substances. Besides deliberate additions of impurities, the Geneva group also reports progress in the preparations of samples of highest purity (barium zirconate crucibles). The alloy series Pr[sub x]Y[sub 1[minus]x]Ba[sub 2]Cu[sub 3]O[sub 7[minus][delta

  3. In-situ minority carrier recombination lifetime measurements at radiation sources for rad-hard IR detector materials

    NASA Astrophysics Data System (ADS)

    Jenkins, Geoffrey D.; Morath, Christian P.; Cowan, Vincent M.

    2014-09-01

    Minority carrier recombination lifetime (MCRL) is a key material parameter for space-based infrared (IR) detector performance affecting both dark current and responsivity. Displacement damage due to energetic massive particles in space environments, such as protons, can significantly degrade the recombination lifetime, thereby reducing detector performance. Therefore, characterizing the change in MCRL with proton dose is of general interest from a radiation-hardness perspective. So-called "bag tests," or measurements taken prior to and following room temperature proton irradiation of the device, are often of limited value to MCRL characterization since thermal annealing effects may be present. Here, progress toward a portable MCRL measurement system employing time resolved photoluminescence (TRPL) is presented. This system can be taken to remote radiation sources where irradiation can be performed on samples followed by TRPL measurements while maintaining temperature throughout. Ideally, this system permits measurement of a lifetime radiation damage factor constant, or the change in lifetime with step-wise changes in proton dose, which is a measure of the defect introduction rate. The pulsed-laser driven TRPL measurement system is able to interrogate IR materials of interest mounted in an optical cryostat held indefinitely at a desired temperature. A system description is given and results of verification measurements are discussed for several IR detector materials.

  4. Design of a circuit for measuring the lifetimes of excited nuclear states of the order of nanoseconds 

    E-print Network

    Kuritzky, Clarence Samuel

    1964-01-01

    DESIGN OF A CIRCUIT FOR MEASURING THE LIFETIMES OF EXCITED NUCLEAR STATES OF THE ORDER OF NANOSECONDS A Thesis By CLARENCE SAMUEL KURITZKY Submitted to the Graduate College of the Texas AS, M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE January 1964 Ma 1 or Sub) ect: Phys ic s DESIGN OF A CIRCUIT FOR MEASURING THE LIFETIMES OF EXCITED NUCLEAR STATES OF THE ORDER OF NANOSECONDS A Thesis By CLARENCE SAMUEL KURITZKY Approved as to style...

  5. Measurement of the B0s Lifetime in the Exclusive Decay Channel B0s-->J\\/psivarphi

    Microsoft Academic Search

    V. M. Abazov; B. Abbott; M. Abolins; B. S. Acharya; D. L. Adams; M. Adams; T. Adams; M. Agelou; J.-L. Agram; S. N. Ahmed; S. H. Ahn; G. D. Alexeev; G. Alkhazov; A. Alton; G. Alverson; G. A. Alves; M. Anastasoaie; S. Anderson; B. Andrieu; Y. Arnoud; A. Askew; B. Åsman; O. Atramentov; C. Autermann; C. Avila; L. Babukhadia; T. C. Bacon; F. Badaud; A. Baden; S. Baffioni; B. Baldin; P. W. Balm; S. Banerjee; E. Barberis; P. Bargassa; P. Baringer; C. Barnes; J. Barreto; J. F. Bartlett; U. Bassler; D. Bauer; A. Bean; S. Beauceron; F. Beaudette; M. Begel; A. Bellavance; S. B. Beri; G. Bernardi; R. Bernhard; I. Bertram; M. Besançon; A. Besson; R. Beuselinck; V. A. Bezzubov; P. C. Bhat; V. Bhatnagar; M. Bhattacharjee; M. Binder; A. Bischoff; K. M. Black; I. Blackler; G. Blazey; F. Blekman; S. Blessing; D. Bloch; U. Blumenschein; A. Boehnlein; O. Boeriu; T. A. Bolton; P. Bonamy; F. Borcherding; G. Borissov; K. Bos; T. Bose; C. Boswell; A. Brandt; G. Briskin; R. Brock; G. Brooijmans; A. Bross; N. J. Buchanan; D. Buchholz; M. Buehler; V. Buescher; S. Burdin; T. H. Burnett; E. Busato; J. M. Butler; J. Bystricky; F. Canelli; W. Carvalho; B. C. Casey; D. Casey; N. M. Cason; H. Castilla-Valdez; S. Chakrabarti; D. Chakraborty; K. M. Chan; A. Chandra; D. Chapin; F. Charles; E. Cheu; L. Chevalier; D. K. Cho; S. Choi; S. Chopra; T. Christiansen; L. Christofek; D. Claes; A. R. Clark; B. Clément; C. Clément; Y. Coadou; D. J. Colling; L. Coney; B. Connolly; M. Cooke; W. E. Cooper; D. Coppage; M. Corcoran; J. Coss; A. Cothenet; M.-C. Cousinou; S. Crépé-Renaudin; M. Cristetiu; M. A. Cummings; D. Cutts; H. da Motta; B. Davies; G. Davies; G. A. Davis; K. de; P. de Jong; S. J. de Jong; E. De Cruz-Burelo; C. De Martins; S. Dean; K. Del Signore; F. Déliot; P. A. Delsart; M. Demarteau; R. Demina; P. Demine; D. Denisov; S. P. Denisov; S. Desai; H. T. Diehl; M. Diesburg; M. Doidge; H. Dong; S. Doulas; L. Duflot; S. R. Dugad; A. Duperrin; J. Dyer; A. Dyshkant; M. Eads; D. Edmunds; T. Edwards; J. Ellison; J. Elmsheuser; J. T. Eltzroth; V. D. Elvira; S. Eno; P. Ermolov; O. V. Eroshin; J. Estrada; D. Evans; H. Evans; A. Evdokimov; V. N. Evdokimov; J. Fast; S. N. Fatakia; D. Fein; L. Feligioni; T. Ferbel; F. Fiedler; F. Filthaut; W. Fisher; H. E. Fisk; F. Fleuret; M. Fortner; H. Fox; W. Freeman; S. Fu; S. Fuess; C. F. Galea; E. Gallas; E. Galyaev; M. Gao; C. Garcia; A. Garcia-Bellido; J. Gardner; V. Gavrilov; P. Gay; D. Gelé; R. Gelhaus; K. Genser; C. E. Gerber; Y. Gershtein; G. Geurkov; G. Ginther; K. Goldmann; T. Golling; B. Gómez; K. Gounder; A. Goussiou; G. Graham; P. D. Grannis; S. Greder; J. A. Green; H. Greenlee; Z. D. Greenwood; E. M. Gregores; S. Grinstein; Ph. Gris; J.-F. Grivaz; L. Groer; S. Grünendahl; M. W. Grünewald; W. Gu; S. N. Gurzhiev; G. Gutierrez; P. Gutierrez; A. Haas; N. J. Hadley; H. Haggerty; S. Hagopian; I. Hall; R. E. Hall; C. Han; L. Han; K. Hanagaki; P. Hanlet; K. Harder; R. Harrington; J. M. Hauptman; R. Hauser; C. Hays; J. Hays; T. Hebbeker; C. Hebert; D. Hedin; J. M. Heinmiller; A. P. Heinson; U. Heintz; C. Hensel; G. Hesketh; M. D. Hildreth; R. Hirosky; J. D. Hobbs; B. Hoeneisen; M. Hohlfeld; S. J. Hong; R. Hooper; S. Hou; P. Houben; Y. Hu; J. Huang; Y. Huang; I. Iashvili; R. Illingworth; A. S. Ito; S. Jabeen; M. Jaffré; S. Jain; V. Jain; K. Jakobs; A. Jenkins; R. Jesik; Y. Jiang; K. Johns; M. Johnson; P. Johnson; A. Jonckheere; P. Jonsson; H. Jöstlein; A. Juste; M. M. Kado; D. Käfer; W. Kahl; S. Kahn; E. Kajfasz; A. M. Kalinin; J. Kalk; D. Karmanov; J. Kasper; D. Kau; Z. Ke; R. Kehoe; S. Kermiche; S. Kesisoglou; A. Khanov; A. Kharchilava; Y. M. Kharzheev; K. H. Kim; B. Klima; M. Klute; J. M. Kohli; M. Kopal; V. M. Korablev; J. Kotcher; B. Kothari; A. V. Kotwal; A. Koubarovsky; O. Kouznetsov; A. V. Kozelov; J. Kozminski; J. Krane; M. R. Krishnaswamy; S. Krzywdzinski; M. Kubantsev; S. Kuleshov; Y. Kulik; S. Kunori; A. Kupco; T. Kurca; V. E. Kuznetsov; S. Lager; N. Lahrichi; G. Landsberg; J. Lazoflores; A.-C. Le Bihan; P. Lebrun; S. W. Lee; W. M. Lee; A. Leflat; C. Leggett; F. Lehner; C. Leonidopoulos; P. Lewis; J. Li; Q. Z. Li; X. Li; J. G. Lima; D. Lincoln; S. L. Linn; J. Linnemann; V. V. Lipaev; R. Lipton; L. Lobo; A. Lobodenko; M. Lokajicek; A. Lounis; J. Lu; H. J. Lubatti; A. Lucotte; L. Lueking; C. Luo; M. Lynker; A. L. Lyon; A. K. Maciel; R. J. Madaras; P. Mättig; A. Magerkurth; A.-M. Magnan; M. Maity; N. Makovec; P. K. Mal; S. Malik; V. L. Malyshev; V. Manankov; H. S. Mao; Y. Maravin; T. Marshall; M. Martens; M. I. Martin; S. E. Mattingly; A. A. Mayorov; R. McCarthy; R. McCroskey; T. McMahon; D. Meder; H. L. Melanson; A. Melnitchouk; X. Meng; M. Merkin; K. W. Merritt; A. Meyer; C. Miao; H. Miettinen; D. Mihalcea; J. Mitrevski; N. Mokhov; J. Molina; N. K. Mondal; H. E. Montgomery; R. W. Moore; M. Mostafa; G. S. Muanza; M. Mulders; Y. D. Mutaf; E. Nagy; F. Nang; M. Narain

    2005-01-01

    Using the exclusive decay B0s-->J\\/psi(mu+mu-)varphi(K+K-), we report the most precise single measurement of the B0s lifetime. The data sample corresponds to an integrated luminosity of approximately 220 pb-1 collected with the D0 detector at the Fermilab Tevatron Collider in 2002 2004. We reconstruct 337 signal candidates, from which we extract the B0s lifetime, tau(B0s)=1.444+0.098-0.090(stat)±0.020(sys) ps. We also report a measurement

  6. Cosmic ray electrons and positrons from 1--100 GeV: HEAT balloon measurements

    NASA Astrophysics Data System (ADS)

    Duvernois, M. A.; Beatty, J. J.; Coutu, S.; Barwick, S. W.; Schneider, E.; Bhattacharyya, A.; Bower, C. R.; Musser, J. A.; Chaput, C. J.; McKee, S.; Tarlé, G.; Tomasch, A. D.; de Nolfo, G. A.; Labrador, A.; Müller, D.; Swordy, S. P.; Torbet, E.; Nutter, S. L.

    1998-04-01

    Observations of the cosmic ray electron and positron energy spectra have been performed with the balloon-borne ``High-Energy Antimatter Telescope'' (HEAT) flown in May 1994 from Fort Sumner, NM, and May 1995 from Lynn Lake, Manitoba in Canada. We summarize the instrument procedures and data analysis, and we present the results, combined from the two flights. These include determinations of the absolute energy spectra of electrons and positrons from 1--50 GeV, and the combined ``all-electron'' spectrum (e^++e^-) up to 100 GeV. We discuss the results in the context of current models of cosmic ray propagation in the Galaxy and find no strong evidence for contributions to the positron intensity beyond purely secondary origin from nuclear interactions in the ISM.

  7. Measurement of the B meson Lifetimes with the Collider Detector at Fermilab

    SciTech Connect

    Uozumi, Satoru; /Tsukuba U.

    2006-01-01

    The lifetimes of the B{sup -}, B{sup 0} and B{sub s}{sup 0} mesons are measured using partially reconstructed semileptonic decays. Following semileptonic decay processes and their charge conjugates are used for this analysis: B{sup -}/B{sup 0} {yields} {ell}{sup -}{nu}D{sup 0}X; B{sup -}/B{sup 0} {yields} {ell}{sup -}{nu}D*{sup +}X; B{sub s}{sup 0} {yields} {ell}{sup -}{nu}D{sub s}{sup +}x, where {ell}{sup -} denotes either a muon or electron. The data are collected during 2002-2004 by the 8 GeV single lepton triggers in CDF Run II at the Fermilab Tevatron Collider. Corresponding integrated luminosity is about 260 and 360 pb{sup -1} used for the B{sup -}/B{sup 0} and B{sub s}{sup 0} lifetime analyses, respectively. With the single lepton triggers, events which contain a muon or electron with a transverse momentum greater than 8 GeV/c are selected. For these lepton candidates, further lepton identification cuts are applied to improve purity of the B semileptonic decay signal. After the lepton selection, three types of charm mesons associated with the lepton candidates are reconstructed. Following exclusive decay modes are used for the charm meson reconstruction: D{sup 0} {yields} K{sup -}{pi}{sup +}; D*{sup +} {yields} D{sup 0}{pi}{sub s}{sup +}, followed by D{sup 0} {yields} K{sup -}{pi}{sup +}; D{sub s}{sup +} {yields} {phi}{pi}{sup +}, followed by {phi} {yields} K{sup +}K{sup -}. Here {pi}{sub s}{sup +} denotes a slow pion from D*{sup +} decay. Species of the reconstructed charm meson identify the parent B meson species. However in the B{sup -}/B{sup 0} semileptonic decays, both mesons decay into the identical lepton + D{sup 0} final state. To solve this mixture of the B components in the D{sup 0} sample, they adopt the following method: First among the inclusive D{sup 0} sample, they look for the D*{sup +} {yields} D{sup 0} {pi}{sub s}{sup +} signal. The inclusive D{sup 0} sample is then split into the two samples of D{sup 0} mesons which are from the D*{sup +} meson and not from D*{sup +}. They use the fact that D*{sup +} sample is dominated by the B{sup 0} component, and the D{sup 0} sample after excluding the D*{sup +} events is dominated by the B{sup -} component. Fraction of remaining mixture of B{sup -}/B{sup 0} components in each sample is estimated using a Monte Carlo simulation. From the lepton + charm meson pairs, they measure the B meson decay lengths to extract the lifetimes. Since the B meson momentum, necessary to calculate the B meson decay time, is not fully reconstructed in semileptonic decays, the missing momentum is corrected using a Monte Carlo simulation during lifetime fits. Also, contributions of various kinds of backgrounds are considered and subtracted. As a result of the fit, the B meson lifetimes are measured to be c{tau}(B{sup -}) = 495.6 {+-} 8.6 {sub -12.8}{sup +13.3} {micro}m; c{tau}(B{sup 0}) = 441.5 {+-} 10.9 {+-} 17.0 {micro}m; c{tau}(B{sub s}{sup 0}) = 414.0 {+-} 16.6 {sub -13.8}{sup +15.6} {micro}m or {tau}(B{sup 0}) = 1.653 {+-} 0.029 {sub -0.031}{sup +0.033} ps; {tau}(B{sup 0}) = 1.473 {+-} 0.036 {+-} 0.054 ps; {tau}(B{sub s}{sup 0}) = 1.381 {+-} 0.055 {sub -0.046}{sup +0.052} ps, and the lifetime ratios to be {tau}(B{sup 0})/{tau}(B{sup 0}) = 1.123 {+-} 0.040 {sub -0.039}{sup +0.041}; {tau}(B{sub s}{sup 0})/{tau}(B{sup 0}) = 0.938 {+-} 0.044 {sub -0.046}{sup +0.049} where the first uncertainty is statistical and the second is systematic.

  8. Radiative return at NLO and the measurement of the hadronic cross-section in electron-positron annihilation

    E-print Network

    G. Rodrigo; H. Czyz; J. H. Kuhn; M. Szopa

    2001-12-13

    Electron-positron annihilation into hadrons plus an energetic photon from initial state radiation allows the hadronic cross-section to be measured over a wide range of energies. The full next-to-leading order QED corrections for the cross-section for e^+ e^- annihilation into a real tagged photon and a virtual photon converting into hadrons are calculated where the tagged photon is radiated off the initial electron or positron. This includes virtual and soft photon corrections to the process e^+ e^- \\to \\gamma +\\gamma^* and the emission of two real hard photons: e^+ e^- \\to \\gamma + \\gamma + \\gamma^*. A Monte Carlo generator has been constructed, which incorporates these corrections and simulates the production of two charged pions or muons plus one or two photons. Predictions are presented for centre-of-mass energies between 1 and 10 GeV, corresponding to the energies of DAPHNE, CLEO-C and B-meson factories.

  9. Development of a high resolution beta camera for a direct measurement of positron distribution on brain surface

    SciTech Connect

    Yamamoto, S. [Kobe City College of Technology, Nishi-ku (Japan); Seki, C.; Kashikura, K. [Akita Lab. (Japan)] [and others

    1996-12-31

    We have developed and tested a high resolution beta camera for a direct measurement of positron distribution on brain surface of animals. The beta camera consists of a thin CaF{sub 2}(Eu) scintillator, a tapered fiber optics plate (taper fiber) and a position sensitive photomultiplier tube (PSPMT). The taper fiber is the key component of the camera. We have developed two types of beta cameras. One is 20mm diameter field of view camera for imaging brain surface of cats. The other is 10mm diameter camera for that of rats. Spatial resolutions of beta camera for cats and rats were 0.8mm FWHM and 0.5mm FWHM, respectively. We confirmed that developed beta cameras may overcome the limitation of the spatial resolution of the positron emission tomography (PET).

  10. On Possible Interpretations of the High Energy Electron-Positron Spectrum Measured by the Fermi Large Area Telescope

    SciTech Connect

    Grasso, D.; Profumo, S.; Strong, A.W.; Baldini, L.; Bellazzini, R.; Bloom, E.D.; Bregeon, J.; Di Bernardo, G.; Gaggero, D.; Giglietto, N.; Kamae, T.; Latronico, L.; Longo, F.; Mazziotta, M.N.; Moiseev, A.A.; Morselli, A.; Ormes, J.F.; Pesce-Rollins, M.; Pohl, M.; Razzano, M.; Sgro, C.

    2009-05-15

    The Fermi-LAT experiment recently reported high precision measurements of the spectrum of cosmic-ray electrons-plus-positrons (CRE) between 20 GeV and 1 TeV. The spectrum shows no prominent spectral features, and is significantly harder than that inferred from several previous experiments. Here we discuss several interpretations of the Fermi results based either on a single large scale Galactic CRE component or by invoking additional electron-positron primary sources, e.g. nearby pulsars or particle Dark Matter annihilation. We show that while the reported Fermi-LAT data alone can be interpreted in terms of a single component scenario, when combined with other complementary experimental results, specifically the CRE spectrum measured by H.E.S.S. and especially the positron fraction reported by PAMELA between 1 and 100 GeV, that class of models fails to provide a consistent interpretation. Rather, we find that several combinations of parameters, involving both the pulsar and dark matter scenarios, allow a consistent description of those results. We also briefly discuss the possibility of discriminating between the pulsar and dark matter interpretations by looking for a possible anisotropy in the CRE flux.

  11. TR-LIF LIFETIME MEASUREMENTS AND HFR+CPOL CALCULATIONS OF RADIATIVE PARAMETERS IN VANADIUM ATOM (V I)

    SciTech Connect

    Wang, Q.; Jiang, L. Y.; Shang, X.; Tian, Y. S.; Dai, Z. W. [College of Physics, Jilin University, Changchun 130012 (China); Quinet, P.; Palmeri, P.; Zhang, W., E-mail: dai@jlu.edu.cn, E-mail: Pascal.quinet@umons.ac.be [Astrophysique et Spectroscopie, Université de Mons—UMONS, 20 Place du Parc, B-7000 Mons (Belgium)

    2014-04-01

    Radiative lifetimes of 79 levels belonging to the 3d {sup 3}4s4p, 3d {sup 4}4p, 3d {sup 3}4s5p, 3d {sup 4}5p, and 3d {sup 3}4s4d configurations of V I with energy from 26,604.807 to 46,862.786 cm{sup –1} have been measured using time-resolved laser-induced fluorescence (TR-LIF) spectroscopy in laser-produced plasma. The lifetime values reported in this paper are in the range of 3.3-494 ns, and the uncertainties of these measurements are within ±10%. A good agreement was obtained with previous data. HFR+CPOL calculations have been performed and used to combine the calculated branching fractions with the available experimental lifetimes to determine semi-empirical transition probabilities for 784 V I transitions.

  12. TR-LIF Lifetime Measurements and HFR+CPOL Calculations of Radiative Parameters in Vanadium Atom (V I)

    NASA Astrophysics Data System (ADS)

    Wang, Q.; Jiang, L. Y.; Quinet, P.; Palmeri, P.; Zhang, W.; Shang, X.; Tian, Y. S.; Dai, Z. W.

    2014-04-01

    Radiative lifetimes of 79 levels belonging to the 3d 34s4p, 3d 44p, 3d 34s5p, 3d 45p, and 3d 34s4d configurations of V I with energy from 26,604.807 to 46,862.786 cm-1 have been measured using time-resolved laser-induced fluorescence (TR-LIF) spectroscopy in laser-produced plasma. The lifetime values reported in this paper are in the range of 3.3-494 ns, and the uncertainties of these measurements are within ±10%. A good agreement was obtained with previous data. HFR+CPOL calculations have been performed and used to combine the calculated branching fractions with the available experimental lifetimes to determine semi-empirical transition probabilities for 784 V I transitions.

  13. The effects of age on dopamine receptors measured by positron tomography in the living human brain

    SciTech Connect

    Wong, D.F.; Wagner, E.N. Jr.; Dannals, R.F.; Frost, J.J.; Ravert, H.V.; Links, J.M.; Folstein, M.F.; Jensen, B.A.; Kuhar, M.J.; Toung, J.T.

    1984-01-01

    C-11 n-methylspiperone has been used to measure dopamine (D2) receptors in the caudate and putamen of 30 normal persons. In vitro studies in rodent brain revealed a high affinity for dopamine (D2) receptors and five fold less for serotonin (S2) receptors. In vivo drug competition studies in rodents demonstrated that 90% of striatal binding is to dopamine receptors. In the frontal cortex, the majority of receptor binding is to serotonin receptors. Thirty normal volunteers aged 19 to 73 years were screened for normality by medical, neurological and neuropsychological examinations. Positron tomography was performed serially for 2 hours after injection. In 10 subjects there was good agreement between activity in arterial samples and that in venous samples from a heated hand. Binding in the dopamine rich caudate and putamen progressively increased while binding in the dopamine poor cerebellum decreased. The dopamine receptor density was estimated by the ratio of the caudate-to-cerebellar mean counts/pixel (Ca/Cb) and putamen-to-cerebellar mean counts/pixel (Pu/Cb). The ratios (Ca/Cb, Pu/Cb) increased linearly with time (r>0.95) for each subject. There was a decrease (Ca/Cb) with age (0.8%/yr) that could be approximated with a linear fit: (Ca/Cb = -.02 age + 3.92, r=.6). For the 21 males alone, the decrease was (1.1%/yr, r=.7 , p <.01), while for the 9 females there was no significant decrease with age. Similar findings were noted in the putamen. This decline in dopamine receptor density with age has been reported in rodent and human autopsy studies, but never before in the living human brain.

  14. Antiproton Lifetime Limits from Recent Cosmic Ray Measurements - Approximate Analytic Solutions of Heliospheric Cosmic Ray Transport

    Microsoft Academic Search

    Dallas C. Kennedy; Steven H. Geer

    1997-01-01

    Laboratory determinations have been made of some of the properties of antimatter, which are, within errors, the charge-conjugated values implied by the corresponding particles. Certain properties, such as the intrinsic decay lifetime, cannot be limited with artificially produced antimatter at a level remotely approaching that possible with matter. The decay lifetime of antiprotons, by the CPT theorem of relativistic quantum

  15. Comparison of Minority Carrier Lifetime Measurements in Superstrate and Substrate CdTe PV Devices: Preprint

    SciTech Connect

    Gessert, T. A.; Dhere, R. G.; Duenow, J. N.; Kuciauskas, D.; Kanevce, A.; Bergeson, J. D.

    2011-07-01

    We discuss typical and alternative procedures to analyze time-resolved photoluminescence (TRPL) measurements of minority carrier lifetime (MCL) with the hope of enhancing our understanding of how this technique may be used to better analyze CdTe photovoltaic (PV) device functionality. Historically, TRPL measurements of the fast recombination rate (t1) have provided insightful correlation with broad device functionality. However, we have more recently found that t1 does not correlate as well with smaller changes in device performance, nor does it correlate well with performance differences observed between superstrate and substrate CdTe PV devices. This study presents TRPL data for both superstrate and substrate CdTe devices where both t1 and the slower TRPL decay (t2) are analyzed. The study shows that changes in performance expected from small changes in device processing may correlate better with t2. Numerical modeling further suggests that, for devices that are expected to have similar drift field in the depletion region, effects of changes in bulk MCL and interface recombination should be more pronounced in t2. Although this technique may provide future guidance to improving CdS/CdTe device performance, it is often difficult to extract statistically precise values for t2, and therefore t2 data may demonstrate significant scatter when correlated with performance parameters.

  16. Very compact all solid state fluorescence lifetime measurement system: preliminary results

    NASA Astrophysics Data System (ADS)

    Erdmann, Rainer; Kell, Gerald; Krahl, Rolf; Ortmann, Uwe; Becker, Wolfgang; Enderlein, Joerg; Klose, Edgar O.

    1994-12-01

    We will demonstrate the operation of the very compact all solid state fluorescence lifetime measurement system FLUO-TIME BQ 2759A. For this purpose we developed a new type of compact driving generator LD 4000 for a set of ps-laserdiodes with wavelengths between 630 nm and 690 nm, which will produce sub 50 ps pulses with up to 200 mW peak power and 3 MHz repetition rate. Using this miniaturized excitation source we are able to investigate a lot of red and NIR dyes. The fluorescence signal will be detected with single photon counting sensitivity by an ultrafast photomultiplier tube with only the size of the transistor (TO8 housing). Spectral resolution is given by a set of bandpass filters or a compact monochromator. With our recently introduced time correlated single photon counting (TCSPC) electronics SPC 300 (a PC-plug-in-card) we have a powerful instrument for data acquisition with highest data throughput. The instrumental response time (IRF) of the complete measurement system is less than 250 ps, allowing the investigation of fluorescence decay time components down to 25 ps using out deconvolution and analysis software package PHYSFIT. This performance can be improved to less than 90 ps IRF using a microchannel plate photomultiplier tube (MCP-PMT) detector. In this paper we demonstrate also the first practical application of this system to standard fluorescence dyes (oxazine, rhodamin).

  17. Measured dose rate constant from oncology patients administered 18F for positron emission tomography

    SciTech Connect

    Quinn, Brian; Holahan, Brian; Aime, Jean; Humm, John; St Germain, Jean; Dauer, Lawrence T. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States); Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States); Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States) and Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States); Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States); Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States) and Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States)

    2012-10-15

    Purpose: Patient exposure rate measurements verify published patient dose rate data and characterize dose rates near 2-18-fluorodeoxyglucose ({sup 18}F-FDG) patients. A specific dose rate constant based on patient exposure rate measurements is a convenient quantity that can be applied to the desired distance, injection activity, and time postinjection to obtain an accurate calculation of cumulative external radiation dose. This study reports exposure rates measured at various locations near positron emission tomography (PET) {sup 18}F-FDG patients prior to PET scanning. These measurements are normalized for the amount of administered activity, measurement distance, and time postinjection and are compared with other published data. Methods: Exposure rates were measured using a calibrated ionization chamber at various body locations from 152 adult oncology patients postvoid after a mean uptake time of 76 min following injection with a mean activity of 490 MBq {sup 18}F-FDG. Data were obtained at nine measurement locations for each patient: three near the head, four near the chest, and two near the feet. Results: On contact with, 30 cm superior to and 30 cm lateral to the head, the mean (75th percentile) dose rates per unit injected activity at 60 min postinjection were 0.482 (0.511), 0.135 (0.155), and 0.193 (0.223) {mu}Sv/MBq h, respectively. On contact with, 30 cm anterior to, 30 cm lateral to and 1 m anterior to the chest, the mean (75th percentile) dose rates per unit injected activity at 60 min postinjection were 0.623 (0.709), 0.254 (0.283), 0.190 (0.218), and 0.067 (0.081) {mu}Sv/MBq h respectively. 30 cm inferior and 30 cm lateral to the feet, the mean (75th percentile) dose rates per unit injected activity at 60 min postinjection were 0.024 (0.022) and 0.039 (0.044) {mu}Sv/MBq h, respectively. Conclusions: The measurements for this study support the use of 0.092 {mu}Sv m{sup 2}/MBq h as a reasonable representation of the dose rate anterior from the chest of patients immediately following injection. This value can then be reliably scaled to the desired time and distance for planning and staff dose evaluation purposes. At distances closer than 1 m, a distance-specific dose rate constant of 0.367 {mu}Sv/MBq h at 30 cm is recommended for accurate calculations. An accurate patient-specific dose rate constant that accounts for patient-specific variables (e.g., distribution and attenuation) will allow an accurate evaluation of the dose rate from a patient injected with an isotope rather than simply utilizing a physical constant.

  18. Measurement of the [bar over B][0 over s] Meson Lifetime in D[+ over s]?[superscript ?] Decays

    E-print Network

    Aaij, R.

    We present a measurement of the ratio of the [bar over B][0 over s] meson lifetime, in the flavor-specific decay to D[+ over s]?[superscript ?], to that of the [bar over B][superscript 0] meson. The pp collision data used ...

  19. Intracellular pH measurements made simple by fluorescent protein probes and the phasor approach to fluorescence lifetime imaging.

    PubMed

    Battisti, Antonella; Digman, Michelle A; Gratton, Enrico; Storti, Barbara; Beltram, Fabio; Bizzarri, Ranieri

    2012-05-25

    A versatile pH-dependent fluorescent protein was applied to intracellular pH measurements by means of the phasor approach to fluorescence lifetime imaging. By this fit-less method we obtain intracellular pH maps under resting or altered physiological conditions by single-photon confocal or two-photon microscopy. PMID:22517076

  20. Magnetic dipole transition rates from measured lifetimes of levels of Be-like and B-like argon ions 

    E-print Network

    Moehs, D. P.; Church, David A.

    1998-01-01

    The lifetimes of the 1s(2)2s2p P-3(2) level of Ar XV and 1s(2)2s(2)2p P-2(3/2) of Ar XIV have been measured using metastable Ar14+ and Ar13+ ions produced by an electron cyclotron resonance ion source, which were subsequently separately captured...

  1. Measurement of the Lifetime of the Bs0 Meson Using the Exclusive Decay Mode Bs0 --> J\\/psi phi

    Microsoft Academic Search

    F. Abe; H. Akimoto; A. Akopian; M. G. Albrow; S. R. Amendolia; D. Amidei; J. Antos; C. Anway-Wiese; S. Aota; G. Apollinari; T. Asakawa; W. Ashmanskas; M. Atac; F. Azfar; P. Azzi-Bacchetta; N. Bacchetta; W. Badgett; S. Bagdasarov; M. W. Bailey; J. Bao; P. de Barbaro; A. Barbaro-Galtieri; V. E. Barnes; B. A. Barnett; E. Barzi; G. Bauer; T. Baumann; F. Bedeschi; S. Behrends; S. Belforte; G. Bellettini; J. Bellinger; D. Benjamin; J. Benlloch; J. Bensinger; D. Benton; A. Beretvas; J. P. Berge; J. Berryhill; S. Bertolucci; A. Bhatti; K. Biery; M. Binkley; D. Bisello; R. E. Blair; C. Blocker; A. Bodek; W. Bokhari; V. Bolognesi; D. Bortoletto; J. Boudreau; L. Breccia; C. Bromberg; N. Bruner; E. Buckley-Geer; H. S. Budd; K. Burkett; G. Busetto; A. Byon-Wagner; K. L. Byrum; J. Cammerata; C. Campagnari; M. Campbell; A. Caner; W. Carithers; D. Carlsmith; A. Castro; D. Cauz; Y. Cen; F. Cervelli; P. S. Chang; P. T. Chang; H. Y. Chao; J. Chapman; M.-T. Cheng; G. Chiarelli; T. Chikamatsu; C. N. Chiou; L. Christofek; S. Cihangir; A. G. Clark; M. Cobal; M. Contreras; J. Conway; J. Cooper; M. Cordelli; C. Couyoumtzelis; D. Crane; D. Cronin-Hennessy; R. Culbertson; J. D. Cunningham; T. Daniels; F. Dejongh; S. Delchamps; S. dell'Agnello; M. dell'Orso; R. Demina; L. Demortier; B. Denby; M. Deninno; P. F. Derwent; T. Devlin; J. R. Dittmann; S. Donati; J. Done; T. Dorigo; A. Dunn; N. Eddy; K. Einsweiler; J. E. Elias; R. Ely; E. Engels Jr.; D. Errede; S. Errede; Q. Fan; I. Fiori; B. Flaugher; G. W. Foster; M. Franklin; M. Frautschi; J. Freeman; J. Friedman; T. A. Fuess; Y. Fukui; S. Funaki; G. Gagliardi; S. Galeotti; M. Gallinaro; M. Garcia-Sciveres; A. F. Garfinkel; C. Gay; S. Geer; D. W. Gerdes; P. Giannetti; N. Giokaris; P. Giromini; L. Gladney; D. Glenzinski; M. Gold; J. Gonzalez; A. Gordon; A. T. Goshaw; K. Goulianos; H. Grassmann; L. Groer; C. Grosso-Pilcher; G. Guillian; R. S. Guo; C. Haber; E. Hafen; S. R. Hahn; R. Handler; R. M. Hans; K. Hara; A. D. Hardman; B. Harral; R. M. Harris; S. A. Hauger; J. Hauser; C. Hawk; E. Hayashi; J. Heinrich; K. D. Hoffman; M. Hohlmann; C. Holck; R. Hollebeek; L. Holloway; A. Hölscher; S. Hong; G. Houk; P. Hu; B. T. Huffman; R. Hughes; J. Huston; J. Huth; J. Hylen; H. Ikeda; M. Incagli; J. Incandela; G. Introzzi; J. Iwai; Y. Iwata; H. Jensen; U. Joshi; R. W. Kadel; E. Kajfasz; H. Kambara; T. Kamon; T. Kaneko; K. Karr; H. Kasha; Y. Kato; T. A. Keaffaber; L. Keeble; K. Kelley; R. D. Kennedy; R. Kephart; P. Kesten; D. Kestenbaum; R. M. Keup; H. Keutelian; F. Keyvan; B. Kharadia; B. J. Kim; D. H. Kim; H. S. Kim; S. B. Kim; S. H. Kim; Y. K. Kim; L. Kirsch; P. Koehn; K. Kondo; J. Konigsberg; S. Kopp; K. Kordas; A. Korytov; W. Koska; E. Kovacs; W. Kowald; M. Krasberg; J. Kroll; M. Kruse; T. Kuwabara; S. E. Kuhlmann; E. Kuns; A. T. Laasanen; N. Labanca; S. Lammel; J. I. Lamoureux; T. Lecompte; S. Leone; J. D. Lewis; P. Limon; M. Lindgren; T. M. Liss; N. Lockyer; O. Long; C. Loomis; M. Loreti; J. Lu; D. Lucchesi; P. Lukens; S. Lusin; J. Lys; K. Maeshima; A. Maghakian; P. Maksimovic; M. Mangano; J. Mansour; M. Mariotti; J. P. Marriner; A. Martin; J. A. Matthews; R. Mattingly; P. McIntyre; P. Melese; A. Menzione; E. Meschi; S. Metzler; C. Miao; T. Miao; G. Michail; R. Miller; H. Minato; S. Miscetti; M. Mishina; H. Mitsushio; T. Miyamoto; S. Miyashita; N. Moggi; Y. Morita; J. Mueller; A. Mukherjee; T. Muller; P. Murat; H. Nakada; I. Nakano; C. Nelson; D. Neuberger; C. Newman-Holmes; M. Ninomiya; L. Nodulman; S. H. Oh; K. E. Ohl; T. Ohmoto; T. Ohsugi; R. Oishi; M. Okabe; T. Okusawa; R. Oliveira; J. Olsen; C. Pagliarone; R. Paoletti; V. Papadimitriou; S. P. Pappas; A. Parri; J. Patrick; G. Pauletta; M. Paulini; A. Perazzo; L. Pescara; M. D. Peters; T. J. Phillips; G. Piacentino; M. Pillai; K. T. Pitts; R. Plunkett; L. Pondrom; J. Proudfoot; F. Ptohos; G. Punzi; K. Ragan; A. Ribon; F. Rimondi; L. Ristori; W. J. Robertson; T. Rodrigo; S. Rolli; J. Romano; L. Rosenson; R. Roser; W. K. Sakumoto; D. Saltzberg; A. Sansoni; L. Santi; H. Sato; V. Scarpine; P. Schlabach; E. E. Schmidt; M. P. Schmidt; A. Scribano; S. Segler; S. Seidel; Y. Seiya; G. Sganos; M. D. Shapiro; N. M. Shaw; Q. Shen; P. F. Shepard; M. Shimojima; M. Shochet; J. Siegrist; A. Sill; P. Sinervo; P. Singh; J. Skarha; K. Sliwa; F. D. Snider; T. Song; J. Spalding; T. Speer; P. Sphicas; F. Spinella; M. Spiropulu; L. Spiegel; L. Stanco; J. Steele; A. Stefanini; K. Strahl; J. Strait; R. Ströhmer; D. Stuart; G. Sullivan; A. Soumarokov; K. Sumorok; J. Suzuki; T. Takada; T. Takahashi; T. Takano; K. Takikawa; N. Tamura; F. Tartarelli; W. Taylor; P. K. Teng; Y. Teramoto; S. Tether; D. Theriot; T. L. Thomas; R. Thun; M. Timko; P. Tipton; A. Titov; S. Tkaczyk; D. Toback; K. Tollefson; A. Tollestrup; J. Tonnison; J. F. de Troconiz; S. Truitt; J. Tseng; N. Turini; T. Uchida; N. Uemura; F. Ukegawa; G. Unal; S. C. van den Brink; S. Vejcik III; G. Velev

    1996-01-01

    The lifetime of the B0s meson is measured using the exclusive decay mode B0s-->J\\/psi phi, where J\\/psi-->mu+mu- and phi-->K+K-. The data sample consists of 110 pb-1 of pp¯ collisions at s = 1.8 TeV, collected by the CDF detector at the Fermilab Tevatron collider during 1992-1995. We find 58+\\/-12 signal events, and the B0s meson lifetime is determined to be

  2. Precision measurement of the mass and lifetime of the ?(b)(0) baryon.

    PubMed

    Aaij, R; Adeva, B; Adinolfi, M; Affolder, A; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Anderson, J; Andreassen, R; Andreotti, M; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Badalov, A; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Batozskaya, V; Battista, V; Bay, A; Beaucourt, L; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Borsato, M; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brodzicka, J; Brook, N H; Brown, H; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Calabrese, R; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carranza-Mejia, H; Carson, L; Carvalho Akiba, K; Casse, G; Cassina, L; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cenci, R; Charles, M; Charpentier, Ph; Chen, S; Cheung, S-F; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Corvo, M; Counts, I; Couturier, B; Cowan, G A; Craik, D C; Cruz Torres, M; Cunliffe, S; Currie, R; D'Ambrosio, C; Dalseno, J; David, P; David, P N Y; Davis, A; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Donleavy, S; Dordei, F; Dorigo, M; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dreimanis, K; Dujany, G; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Ely, S; Esen, S; Evans, H-M; Evans, T; Falabella, A; Färber, C; Farinelli, C; Farley, N; Farry, S; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fiorini, M; Firlej, M; Fitzpatrick, C; Fiutowski, T; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Fu, J; Furfaro, E; Gallas Torreira, A; Galli, D; Gallorini, S; Gambetta, S; Gandelman, M; Gandini, P; Gao, Y; Garofoli, J; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gavardi, L; Gavrilov, G; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gianelle, A; Giani', S; Gibson, V; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Gotti, C; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grillo, L; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Han, X; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hartmann, T; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Henry, L; Hernando Morata, J A; van Herwijnen, E; Heß, M; Hicheur, A; Hill, D; Hoballah, M; Hombach, C; Hulsbergen, W; Hunt, P; Hussain, N; Hutchcroft, D; Hynds, D; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jalocha, J; Jans, E; Jaton, P; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kaballo, M; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Karodia, S; Kelsey, M; Kenyon, I R; Ketel, T; Khanji, B; Khurewathanakul, C; Klaver, S; Kochebina, O; Kolpin, M; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucewicz, W; Kucharczyk, M; Kudryavtsev, V; Kurek, K; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Langhans, B; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Liles, M; Lindner, R; Linn, C; Lionetto, F; Liu, B; Liu, G; Lohn, S; Longstaff, I; Lopes, J H; Lopez-March, N; Lowdon, P; Lu, H; Lucchesi, D; Luo, H; Lupato, A; Luppi, E; Lupton, O; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Manca, G; Mancinelli, G; Maratas, J; Marchand, J F; Marconi, U; Marin Benito, C; Marino, P; Märki, R; Marks, J; Martellotti, G; Martens, A; Martín Sánchez, A; Martinelli, M

    2014-07-18

    Using a proton-proton collision data sample corresponding to an integrated luminosity of 3 fb(-1) collected by LHCb at center-of-mass energies of 7 and 8 TeV, about 3800 ?(b)(0) ? ?(c)(+)?(-), ?(c)(+)) ? pK(-)?(+) signal decays are reconstructed. From this sample, the first measurement of the ?(b)(0) baryon lifetime is made, relative to that of the ?(b)(0) baryon. The mass differences M(?(b)(0))-M(?(b)(0)) and M(?(c)(+))-M(?(c)(+)) are also measured with precision more than 4 times better than the current world averages. The resulting values are ?(?(b)(0))/?(?)(b)(0)) = 1.006 ± 0.018 ± 0.010,M(?(b)(0))-M(?(b)(0)) = 172.44 ± 0.39 ± 0.17 MeV/c(2),M(?(c)(+))-M(?(c)(+)) = 181.51 ± 0.14 ± 0.10 MeV/c(2),where the first uncertainty is statistical and the second is systematic. The relative rate of ?(b)(0) to ?(b)(0) baryon production is measured to be f(?)(b)(0))/f(?)(b)(0))B(?(b)(0) ? ?(c)(+)?(-))/B(?(b)(0) ? ?(c)(+)?(-))B(?(c)(+) ? pK(-)?(+))/B(?(c)(+) ? pK(-)}?(+)) = (1.88 ± 0.04 ± 0.03) × 10(-2),where the first factor is the ratio of fragmentation fractions, b ? ?(b)(0) relative to b ? ?(b)(0). Relative production rates as functions of transverse momentum and pseudorapidity are also presented. PMID:25083633

  3. The effect of external dynamic loads on the lifetime of rolling element bearings: accurate measurement of the bearing behaviour

    NASA Astrophysics Data System (ADS)

    Jacobs, W.; Boonen, R.; Sas, P.; Moens, D.

    2012-05-01

    Accurate prediction of the lifetime of rolling element bearings is a crucial step towards a reliable design of many rotating machines. Recent research emphasizes an important influence of external dynamic loads on the lifetime of bearings. However, most lifetime calculations of bearings are based on the classical ISO 281 standard, neglecting this influence. For bearings subjected to highly varying loads, this leads to inaccurate estimations of the lifetime, and therefore excessive safety factors during the design and unexpected failures during operation. This paper presents a novel test rig, developed to analyse the behaviour of rolling element bearings subjected to highly varying loads. Since bearings are very precise machine components, their motion can only be measured in an accurately controlled environment. Otherwise, noise from other components and external influences such as temperature variations will dominate the measurements. The test rig is optimised to perform accurate measurements of the bearing behaviour. Also, the test bearing is fitted in a modular structure, which guarantees precise mounting and allows testing different types and sizes of bearings. Finally, a fully controlled multi-axial static and dynamic load is imposed on the bearing, while its behaviour is monitored with capacitive proximity probes.

  4. Measurement of the Lambda(b) lifetime in the exclusive decay Lambda(b) ---> J / psi Lambda

    SciTech Connect

    Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Aguilo, E.; Ahn, S.H.; Ahsan, M.; Alexeev, G.D.; Alkhazov, G.; /Buenos Aires U. /Rio de Janeiro, CBPF /Rio de Janeiro State U. /Sao Paulo, IFT /Alberta U. /Simon Fraser U. /York U., Canada /McGill U. /Hefei, CUST /Andes U., Bogota /Charles U.

    2007-04-01

    We have measured the {lambda}{sub b} lifetime using the exclusive decay {lambda}{sub b}{yields}J/{psi}{lambda}, based on 1.2 fb{sup -1} of data collected with the D0 detector during 2002-2006. From 171 reconstructed {lambda}{sub b} decays, where the J/{psi} and {lambda} are identified via the decays J/{psi}{yields}{mu}{sup +}{mu}{sup -} and {lambda}{yields}p{pi}, we measured the {lambda}{sub b} lifetime to be {tau}({lambda}{sub b})=1.218{sub -0.115}{sup +0.130}(stat){+-}0.042(syst) ps. We also measured the B{sup 0} lifetime in the decay B{sup 0}{yields}J/{psi}({mu}{sup +}{mu}{sup -})K{sub S}{sup 0}({pi}{sup +}{pi}{sup -}) to be {tau}(B{sup 0})=1.501{sub -0.074}{sup +0.078}(stat){+-}0.050(syst) ps, yielding a lifetime ratio of {tau}({lambda}{sub b})/{tau}(B{sup 0})=0.811{sub -0.087}{sup +0.096}(stat){+-}0.034(syst = )

  5. Measurement of the Inclusive B-Lifetime Using $\\rm {J/\\psi}$'s at the CDF Experiment

    SciTech Connect

    Wenzel, Hans-Joachim; /RWTH Aachen U.

    1993-08-01

    This dissertation describes the measurement of the average B hadron lifetime using a high statistics sample of B {yields} J/{psi}X decays produced in p{bar p} collisions at a center of mass energy of {radical}s = 1.8 TeV at the Fermilab Tevatron. The integrated luminosity of the sample is 10.1 pb{sup -1} recorded with the Collider Detector at Fermilab (CDF). In this analysis the decay vertex of the decay J/{psi} {yields} {mu}{sup +}{mu}{sup -} as reconstructed by a silicon vertex detector is used to extract the lifetime from the data. This measurement is the average over all b-hadrons produced weighted by the product of their branching ratios into J/{psi} and their production cross sections. We find the following value for the average b hadron lifetime: {tau}{sub B} = 1.46 {+-} 0.06(stat.) {+-} 0.06(syst.) ps. This is the first measurement of the b-hadron lifetime at a hadron collider. It demonstrates that it is possible to access the large b-quark production cross section in p{bar p} collisions and to achieve high statistics even in modes which have small product branching ratios as in this case: BR(B {yields} J/{psi}X) {center_dot} BR(J/{psi} {yields} {mu}{sup +}{mu}{sup -}) = 7.7 x 10{sup -4}.

  6. Picosecond planar laser-induced fluorescence measurements of OH A 2 ( 2) lifetime and energy transfer in atmospheric pressure flames

    NASA Astrophysics Data System (ADS)

    Bormann, Frank C.; Nielsen, Tim; Burrows, Michael; Andresen, Peter

    1997-08-01

    A picosecond, excimer-Raman laser (268 nm, 400 ps FWHM) was used for laser sheet excitation of OH in the (2, 0) band. The fluorescence was detected with a fast-gated, intensified camera (400-ps gate width). The effective collisional lifetime of the spectrally integrated fluorescence was measured in two dimensions by shifting the intensifier gate across the decay curve. The average lifetime is 2.0 ns for a stoichiometric methane air flame with spatial variations of 10 . Shorter collisional lifetimes were measured for rich flame conditions that are due to a higher number density of the quenchers. Vibrational energy transfer (VET) was observed in premixed methane air and methane oxygen flames by putting the fast-gated camera behind a spectrometer. The spectrum of the methane air flame shows strong VET in contrast with the methane oxygen flame. This is because N 2 is a weak electronic quencher but a strong VET agent. By fitting the measured time dependence of the different vibrational populations ( 2, 1, 0) to a four-level model, rate constants for quenching and VET were determined. For the lower states ( 0, 1) our results are in good agreement with literature values. For a prediction of a spectrally integrated, collisional lifetime in a known collisional environment it is important to consider not only the quenching but also the amount of energy transfer in the excited state as well as the spectral detection sensitivity.

  7. Dynamical heterogeneity in glassy o-terphenyl. 2. Measurement of environment structure lifetime using reversible reactions.

    PubMed

    Grebenkin, S Yu

    2008-12-01

    A new method is proposed for measuring the lifetime of heterogeneities in a glassy matrix. UV-vis absorption spectroscopy has been used to monitor the kinetics of photoinduced cis-->trans isomerization of 1-naphthyl-azomethoxybenzene (NAMB) in o-terphenyl (OTP) below T(g). The dependence of isomerization rate on the duration of dark interval after generation of cis molecules was established; an increase in the dark interval causes a decrease in isomerization rate. This dependence is shown to be due to the change in the local environment of NAMB molecules. The time required for the environment to change was estimated over a temperature range of 234 (T(g) - 9 K) to 241.5 K (T(g) - 1.5 K). The change in the environment of the guest molecules has been interpreted in terms of the exchange processes. The values obtained for the exchange time coincide with the rotation times of the NAMB molecule. Also, it is shown that the time of structural rearrangement of the environment near the fast reacting molecules is of the same order of magnitude as the time of structural rearrangement of the environment near the slow reacting ones. PMID:19006268

  8. High-spin lifetime measurements in the N=Z nucleus {sup 72}Kr

    SciTech Connect

    Andreoiu, C. [Department of Physics, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 3BX (United Kingdom); Svensson, C. E.; Finlay, P.; Garrett, P. E.; Grinyer, G. F.; Hyland, B.; Phillips, A. A.; Schumaker, M. A.; Valiente-Dobon, J. J. [Department of Physics, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Afanasjev, A. V. [Department of Physics and Astronomy, Mississippi State University, Starkville, Mississippi 39762 (United States); Austin, R. A. E. [McMaster University, Hamilton, Ontario, L8S 4K1 (Canada); Carpenter, M. P.; Freeman, S. J.; Greene, J.; Moore, F.; Mukherjee, G.; Seweryniak, D. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60436 (United States); Dashdorj, D. [North Carolina State University, Raleigh, Norht Carolina 27695 (United States); Goergen, A. [CEA Saclay, Daphnia/SphN, F-91191 Gif-sur-Yvette Cedex (France); Jenkins, D. [Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom)] (and others)

    2007-04-15

    High-spin states in the N=Z nucleus {sup 72}Kr have been populated in the {sup 40}Ca({sup 40}Ca, 2{alpha}){sup 72}Kr fusion-evaporation reaction at a beam energy of 165 MeV using the Gammasphere array for {gamma}-ray detection coupled to the Microball array for charged particle detection. The previously observed bands in {sup 72}Kr were extended to an excitation energy of {approx}24 MeV and angular momentum of 30({Dirac_h}/2{pi}). Using the Doppler shift attenuation method the lifetimes of high-spin states were measured for the first time. Excellent agreement between the results of calculations within the isovector mean field theory and experiment is observed both for rotational and deformation properties. No enhancement of quadrupole deformation expected in the presence of isoscalar t=0 np pairing is observed. Current data do not show any evidence for the existence of the isoscalar np pairing.

  9. Volatility of organic molecular markers used for source apportionment analysis: measurements and implications for atmospheric lifetime.

    PubMed

    May, Andrew A; Saleh, Rawad; Hennigan, Christopher J; Donahue, Neil M; Robinson, Allen L

    2012-11-20

    Molecular markers are organic species used to define fingerprints for source apportionment of ambient fine particulate matter. Traditionally, these markers have been assumed to be stable in the atmosphere. This work investigates the gas-particle partitioning of eight organic species used as molecular markers in receptor models for biomass burning (levoglucosan), motor vehicles (5?-cholestane, n-hexacosane, n-triacontane, 1,2-benz[a]anthracene, coronene), and meat cooking (cholesterol, oleic acid). Experiments were conducted using a thermodenuder to measure the evaporation of single component particles. The data were analyzed using the integrated volume method to determine saturation concentrations and enthalpies of vaporization for each compound. The results indicate that appreciable quantities (>10%) of most of these markers exist in the gas phase under typical atmospheric conditions. Therefore, these species should be considered semivolatile. Predictions from a chemical kinetics model indicate that gas-particle partitioning has important effects on the atmospheric lifetime of these species. The atmospheric decay of semivolatile compounds proceeds much more rapidly than nonvolatile compounds because gas-phase oxidation induces evaporation of particle-phase material. Therefore, both gas-particle partitioning and chemical reactions need to be accounted for when semivolatile molecular markers are used for source apportionment studies. PMID:23013599

  10. Measurement and model assessment of fluorescence lifetime sensing in multiply scattering media 

    E-print Network

    Kuwana, Eddy

    2005-08-29

    ) the generation of fluorescence from dyes exhibiting multi-exponential or more complex kinetics and (ii) its propagation in scattering media. In the preliminary study, fluorescence lifetime spectroscopy is investigated in tissue-like scattering solution. Two...

  11. Recombination activity of iron-related complexes in silicon studied by temperature dependent carrier lifetime measurements

    Microsoft Academic Search

    A. Kaniava; A. L. P. Rotondaro; J. Vanhellemont; U. Menczigar; E. Gaubas

    1995-01-01

    Carrier recombination centers related with iron complexes in p-type silicon are studied by microwave and light-induced absorption techniques. Both thermal- and photoactivation are used to decompose iron–boron pairs and to study the impact on the recombination lifetime. Due to photodissociation of iron–boron pairs the lifetime increases for high level injection. Efficient recombination occurs via an acceptor level at Ec?0.29 eV

  12. Positron annihilation study of proton-irradiated reactor pressure vessel steels

    NASA Astrophysics Data System (ADS)

    Liu, Xiangbing; Wang, Rongshan; Ren, Ai; Huang, Ping; Wu, Yichu; Jiang, Jing; Zhang, Chonghong; Wang, Xitao

    2012-10-01

    The microstructures, irradiation-induced defects and changes of mechanical property of Chinese domestic A508-3 steels after proton irradiation were investigated by TEM, positron lifetime, slow positron beam Doppler broadening spectroscopy and hardness measurements. The defects were induced by 240 keV proton irradiation with fluences of 1.25×1017 ions cm-2 (0.26 dpa), 2.5×1017 ions cm-2 (0.5 dpa), and 5.0×1017 ions cm-2 (1.0 dpa). The TEM observation revealed that the as-received steel had typical bainitic-ferritic microstructures. It was also observed that Doppler broadening S-parameter and average lifetime increased with dose level owing to the formation of defects and voids induced by proton irradiation. The correlation between positron parameters and hardness was found.

  13. Brain metabolism in autism. Resting cerebral glucose utilization rates as measured with positron emission tomography

    SciTech Connect

    Rumsey, J.M.; Duara, R.; Grady, C.; Rapoport, J.L.; Margolin, R.A.; Rapoport, S.I.; Cutler, N.R.

    1985-05-01

    The cerebral metabolic rate for glucose was studied in ten men (mean age = 26 years) with well-documented histories of infantile autism and in 15 age-matched normal male controls using positron emission tomography and (F-18) 2-fluoro-2-deoxy-D-glucose. Positron emission tomography was completed during rest, with reduced visual and auditory stimulation. While the autistic group as a whole showed significantly elevated glucose utilization in widespread regions of the brain, there was considerable overlap between the two groups. No brain region showed a reduced metabolic rate in the autistic group. Significantly more autistic, as compared with control, subjects showed extreme relative metabolic rates (ratios of regional metabolic rates to whole brain rates and asymmetries) in one or more brain regions.

  14. Measurement of the Energy Spectrum of Secondary Electrons Ejected from Solids by Positron Impact

    Microsoft Academic Search

    N. Overton; P. G. Coleman

    1997-01-01

    Energy distributions of fast secondary electrons ejected from Cu and Si bombarded by positrons of energies in the range 50 to 2000 eV, incident at glancing angles \\\\(<=5°\\\\) and at 35°, have been fit to the form AE-m proposed by E. N. Sickafus. The absence of electron backscattering and the reduction of cascade effects common in electron-stimulated secondary electron spectra

  15. Preliminary results of a slow positron study on an epoxy polymer

    NASA Astrophysics Data System (ADS)

    Jean, Y. C.; Dai, G. H.; Shi, H.; Suzuki, R.; Kobayashi, Y.

    1994-06-01

    The positron annihilation lifetime spectra and positronium energy spectra of an epoxy polymer with a 5:2:3 equivalent ratio of DGEBA/DDA/DAB epoxy (Tg=52 °C) are measured as a function of temperature and of positron incident energies (0-5 keV). Preliminary results from these experiments show: (1) a 1-9% of long-lived o-Ps are emited from the energy surface, (2) the lifetime of o-Ps near the surface is about three times longer than that in the bulk, (3) the positron lifetime spectra obtained from the incident positron energy exceeding 2 keV are essentially the same as those in the bulk, and (4) the energies of emitted Ps are distributed from thermal to about 100 eV. These results are discussed in terms of the potential uses of slow positrons in probing the free-volume hole properties of thin films and near surfaces of polymeric materials.

  16. The epidermal Ca(2+) gradient: Measurement using the phasor representation of fluorescent lifetime imaging.

    PubMed

    Celli, A; Sanchez, S; Behne, M; Hazlett, T; Gratton, E; Mauro, T

    2010-03-01

    Ionic gradients are found across a variety of tissues and organs. In this report, we apply the phasor representation of fluorescence lifetime imaging data to the quantitative study of ionic concentrations in tissues, overcoming technical problems of tissue thickness, concentration artifacts of ion-sensitive dyes, and calibration across inhomogeneous tissue. We used epidermis as a model system, as Ca(2+) gradients in this organ have been shown previously to control essential biologic processes of differentiation and formation of the epidermal permeability barrier. The approach described here allowed much better localization of Ca(2+) stores than those used in previous studies, and revealed that the bulk of free Ca(2+) measured in the epidermis comes from intracellular Ca(2+) stores such as the Golgi and the endoplasmic reticulum, with extracellular Ca(2+) making a relatively small contribution to the epidermal Ca(2+) gradient. Due to the high spatial resolution of two-photon microscopy, we were able to measure a marked heterogeneity in average calcium concentrations from cell to cell in the basal keratinocytes. This finding, not reported in previous studies, calls into question the long-held hypothesis that keratinocytes increase intracellular Ca(2+), cease proliferation, and differentiate passively in response to changes in extracellular Ca(2+). The experimental results obtained using this approach illustrate the power of the experimental and analytical techniques outlined in this report. Our approach can be used in mechanistic studies to address the formation, maintenance, and function of the epidermal Ca(2+) gradient, and it should be broadly applicable to the study of other tissues with ionic gradients. PMID:20197045

  17. Positron annihilation study of aluminum, titanium, and iron alloys surface after shot peening

    NASA Astrophysics Data System (ADS)

    Zaleski, R.; Zaleski, K.; Gorgol, M.; Wiertel, M.

    2015-05-01

    Shot peening influence on alloys based on iron, aluminum, and titanium was studied using positron annihilation lifetime spectroscopy (PALS) and residual stress measurements. The PALS spectra were analyzed assuming two lifetime components. While the residual stresses change in a similar way in all the samples, the PALS results show an opposite tendency of a component relative intensities change with the time of shot peening for the Ti alloy as compared to steel or the Al alloy. A comparison between the depth profiles of positron implantation and the residual stress distribution reveals that the positron range covers a whole depth where residual stress is observed only in the Ti alloy. Based on this observation, the evolution of the defect concentration is presumed, consisting in migration of large defects away from the surface, while only smaller ones remain close to the surface. Furthermore, the positron lifetime distribution in the Al alloy was determined using the MELT program. The results showed that the initial single, wide distribution of lifetime splits into two narrower ones with increasing shot peening time.

  18. First result from the Alpha Magnetic Spectrometer on the International Space Station: precision measurement of the positron fraction in primary cosmic rays of 0.5-350 GeV.

    PubMed

    Aguilar, M; Alberti, G; Alpat, B; Alvino, A; Ambrosi, G; Andeen, K; Anderhub, H; Arruda, L; Azzarello, P; Bachlechner, A; Barao, F; Baret, B; Barrau, A; Barrin, L; Bartoloni, A; Basara, L; Basili, A; Batalha, L; Bates, J; Battiston, R; Bazo, J; Becker, R; Becker, U; Behlmann, M; Beischer, B; Berdugo, J; Berges, P; Bertucci, B; Bigongiari, G; Biland, A; Bindi, V; Bizzaglia, S; Boella, G; de Boer, W; Bollweg, K; Bolmont, J; Borgia, B; Borsini, S; Boschini, M J; Boudoul, G; Bourquin, M; Brun, P; Buénerd, M; Burger, J; Burger, W; Cadoux, F; Cai, X D; Capell, M; Casadei, D; Casaus, J; Cascioli, V; Castellini, G; Cernuda, I; Cervelli, F; Chae, M J; Chang, Y H; Chen, A I; Chen, C R; Chen, H; Cheng, G M; Chen, H S; Cheng, L; Chernoplyiokov, N; Chikanian, A; Choumilov, E; Choutko, V; Chung, C H; Clark, C; Clavero, R; Coignet, G; Commichau, V; Consolandi, C; Contin, A; Corti, C; Costado Dios, M T; Coste, B; Crespo, D; Cui, Z; Dai, M; Delgado, C; Della Torre, S; Demirkoz, B; Dennett, P; Derome, L; Di Falco, S; Diao, X H; Diago, A; Djambazov, L; Díaz, C; von Doetinchem, P; Du, W J; Dubois, J M; Duperay, R; Duranti, M; D'Urso, D; Egorov, A; Eline, A; Eppling, F J; Eronen, T; van Es, J; Esser, H; Falvard, A; Fiandrini, E; Fiasson, A; Finch, E; Fisher, P; Flood, K; Foglio, R; Fohey, M; Fopp, S; Fouque, N; Galaktionov, Y; Gallilee, M; Gallin-Martel, L; Gallucci, G; García, B; García, J; García-López, R; García-Tabares, L; Gargiulo, C; Gast, H; Gebauer, I; Gentile, S; Gervasi, M; Gillard, W; Giovacchini, F; Girard, L; Goglov, P; Gong, J; Goy-Henningsen, C; Grandi, D; Graziani, M; Grechko, A; Gross, A; Guerri, I; de la Guía, C; Guo, K H; Habiby, M; Haino, S; Hauler, F; He, Z H; Heil, M; Heilig, J; Hermel, R; Hofer, H; Huang, Z C; Hungerford, W; Incagli, M; Ionica, M; Jacholkowska, A; Jang, W Y; Jinchi, H; Jongmanns, M; Journet, L; Jungermann, L; Karpinski, W; Kim, G N; Kim, K S; Kirn, Th; Kossakowski, R; Koulemzine, A; Kounina, O; Kounine, A; Koutsenko, V; Krafczyk, M S; Laudi, E; Laurenti, G; Lauritzen, C; Lebedev, A; Lee, M W; Lee, S C; Leluc, C; León Vargas, H; Lepareur, V; Li, J Q; Li, Q; Li, T X; Li, W; Li, Z H; Lipari, P; Lin, C H; Liu, D; Liu, H; Lomtadze, T; Lu, Y S; Lucidi, S; Lübelsmeyer, K; Luo, J Z; Lustermann, W; Lv, S; Madsen, J; Majka, R; Malinin, A; Mañá, C; Marín, J; Martin, T; Martínez, G; Masciocchi, F; Masi, N; Maurin, D; McInturff, A; McIntyre, P; Menchaca-Rocha, A; Meng, Q; Menichelli, M; Mereu, I; Millinger, M; Mo, D C; Molina, M; Mott, P; Mujunen, A; Natale, S; Nemeth, P; Ni, J Q; Nikonov, N; Nozzoli, F; Nunes, P; Obermeier, A; Oh, S; Oliva, A; Palmonari, F; Palomares, C; Paniccia, M; Papi, A; Park, W H; Pauluzzi, M; Pauss, F; Pauw, A; Pedreschi, E; Pensotti, S; Pereira, R; Perrin, E; Pessina, G; Pierschel, G; Pilo, F; Piluso, A; Pizzolotto, C; Plyaskin, V; Pochon, J; Pohl, M; Poireau, V; Porter, S; Pouxe, J; Putze, A; Quadrani, L; Qi, X N; Rancoita, P G; Rapin, D; Ren, Z L; Ricol, J S; Riihonen, E; Rodríguez, I; Roeser, U; Rosier-Lees, S; Rossi, L; Rozhkov, A; Rozza, D; Sabellek, A; Sagdeev, R; Sandweiss, J; Santos, B; Saouter, P; Sarchioni, M; Schael, S; Schinzel, D; Schmanau, M; Schwering, G; Schulz von Dratzig, A; Scolieri, G; Seo, E S; Shan, B S; Shi, J Y; Shi, Y M; Siedenburg, T; Siedling, R; Son, D; Spada, F; Spinella, F; Steuer, M; Stiff, K; Sun, W; Sun, W H; Sun, X H; Tacconi, M; Tang, C P; Tang, X W; Tang, Z C; Tao, L; Tassan-Viol, J; Ting, Samuel C C; Ting, S M; Titus, C; Tomassetti, N; Toral, F; Torsti, J; Tsai, J R; Tutt, J C; Ulbricht, J; Urban, T; Vagelli, V; Valente, E; Vannini, C; Valtonen, E; Vargas Trevino, M; Vaurynovich, S; Vecchi, M; Vergain, M; Verlaat, B; Vescovi, C; Vialle, J P; Viertel, G; Volpini, G; Wang, D; Wang, N H; Wang, Q L; Wang, R S; Wang, X; Wang, Z X; Wallraff, W; Weng, Z L; Willenbrock, M; Wlochal, M; Wu, H; Wu, K Y; Wu, Z S; Xiao, W J; Xie, S; Xiong, R Q; Xin, G M; Xu, N S; Xu, W; Yan, Q; Yang, J; Yang, M; Ye, Q H; Yi, H; Yu, Y J; Yu, Z Q; Zeissler, S; Zhang, J G; Zhang, Z; Zhang, M M; Zheng, Z M; Zhuang, H L; Zhukov, V; Zichichi, A; Zuccon, P; Zurbach, C

    2013-04-01

    A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8 × 10(6) positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to ? 250??GeV, but, from 20 to 250 GeV, the slope decreases by an order of magnitude. The positron fraction spectrum shows no fine structure, and the positron to electron ratio shows no observable anisotropy. Together, these features show the existence of new physical phenomena. PMID:25166975

  19. First Result from the Alpha Magnetic Spectrometer on the International Space Station: Precision Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5-350 GeV

    NASA Astrophysics Data System (ADS)

    Aguilar, M.; Alberti, G.; Alpat, B.; Alvino, A.; Ambrosi, G.; Andeen, K.; Anderhub, H.; Arruda, L.; Azzarello, P.; Bachlechner, A.; Barao, F.; Baret, B.; Barrau, A.; Barrin, L.; Bartoloni, A.; Basara, L.; Basili, A.; Batalha, L.; Bates, J.; Battiston, R.; Bazo, J.; Becker, R.; Becker, U.; Behlmann, M.; Beischer, B.; Berdugo, J.; Berges, P.; Bertucci, B.; Bigongiari, G.; Biland, A.; Bindi, V.; Bizzaglia, S.; Boella, G.; de Boer, W.; Bollweg, K.; Bolmont, J.; Borgia, B.; Borsini, S.; Boschini, M. J.; Boudoul, G.; Bourquin, M.; Brun, P.; Buénerd, M.; Burger, J.; Burger, W.; Cadoux, F.; Cai, X. D.; Capell, M.; Casadei, D.; Casaus, J.; Cascioli, V.; Castellini, G.; Cernuda, I.; Cervelli, F.; Chae, M. J.; Chang, Y. H.; Chen, A. I.; Chen, C. R.; Chen, H.; Cheng, G. M.; Chen, H. S.; Cheng, L.; Chernoplyiokov, N.; Chikanian, A.; Choumilov, E.; Choutko, V.; Chung, C. H.; Clark, C.; Clavero, R.; Coignet, G.; Commichau, V.; Consolandi, C.; Contin, A.; Corti, C.; Costado Dios, M. T.; Coste, B.; Crespo, D.; Cui, Z.; Dai, M.; Delgado, C.; Della Torre, S.; Demirkoz, B.; Dennett, P.; Derome, L.; Di Falco, S.; Diao, X. H.; Diago, A.; Djambazov, L.; Díaz, C.; von Doetinchem, P.; Du, W. J.; Dubois, J. M.; Duperay, R.; Duranti, M.; D'Urso, D.; Egorov, A.; Eline, A.; Eppling, F. J.; Eronen, T.; van Es, J.; Esser, H.; Falvard, A.; Fiandrini, E.; Fiasson, A.; Finch, E.; Fisher, P.; Flood, K.; Foglio, R.; Fohey, M.; Fopp, S.; Fouque, N.; Galaktionov, Y.; Gallilee, M.; Gallin-Martel, L.; Gallucci, G.; García, B.; García, J.; García-López, R.; García-Tabares, L.; Gargiulo, C.; Gast, H.; Gebauer, I.; Gentile, S.; Gervasi, M.; Gillard, W.; Giovacchini, F.; Girard, L.; Goglov, P.; Gong, J.; Goy-Henningsen, C.; Grandi, D.; Graziani, M.; Grechko, A.; Gross, A.; Guerri, I.; de la Guía, C.; Guo, K. H.; Habiby, M.; Haino, S.; Hauler, F.; He, Z. H.; Heil, M.; Heilig, J.; Hermel, R.; Hofer, H.; Huang, Z. C.; Hungerford, W.; Incagli, M.; Ionica, M.; Jacholkowska, A.; Jang, W. Y.; Jinchi, H.; Jongmanns, M.; Journet, L.; Jungermann, L.; Karpinski, W.; Kim, G. N.; Kim, K. S.; Kirn, Th.; Kossakowski, R.; Koulemzine, A.; Kounina, O.; Kounine, A.; Koutsenko, V.; Krafczyk, M. S.; Laudi, E.; Laurenti, G.; Lauritzen, C.; Lebedev, A.; Lee, M. W.; Lee, S. C.; Leluc, C.; León Vargas, H.; Lepareur, V.; Li, J. Q.; Li, Q.; Li, T. X.; Li, W.; Li, Z. H.; Lipari, P.; Lin, C. H.; Liu, D.; Liu, H.; Lomtadze, T.; Lu, Y. S.; Lucidi, S.; Lübelsmeyer, K.; Luo, J. Z.; Lustermann, W.; Lv, S.; Madsen, J.; Majka, R.; Malinin, A.; Mañá, C.; Marín, J.; Martin, T.; Martínez, G.; Masciocchi, F.; Masi, N.; Maurin, D.; McInturff, A.; McIntyre, P.; Menchaca-Rocha, A.; Meng, Q.; Menichelli, M.; Mereu, I.; Millinger, M.; Mo, D. C.; Molina, M.; Mott, P.; Mujunen, A.; Natale, S.; Nemeth, P.; Ni, J. Q.; Nikonov, N.; Nozzoli, F.; Nunes, P.; Obermeier, A.; Oh, S.; Oliva, A.; Palmonari, F.; Palomares, C.; Paniccia, M.; Papi, A.; Park, W. H.; Pauluzzi, M.; Pauss, F.; Pauw, A.; Pedreschi, E.; Pensotti, S.; Pereira, R.; Perrin, E.; Pessina, G.; Pierschel, G.; Pilo, F.; Piluso, A.; Pizzolotto, C.; Plyaskin, V.; Pochon, J.; Pohl, M.; Poireau, V.; Porter, S.; Pouxe, J.; Putze, A.; Quadrani, L.; Qi, X. N.; Rancoita, P. G.; Rapin, D.; Ren, Z. L.; Ricol, J. S.; Riihonen, E.; Rodríguez, I.; Roeser, U.; Rosier-Lees, S.; Rossi, L.; Rozhkov, A.; Rozza, D.; Sabellek, A.; Sagdeev, R.; Sandweiss, J.; Santos, B.; Saouter, P.; Sarchioni, M.; Schael, S.; Schinzel, D.; Schmanau, M.; Schwering, G.; Schulz von Dratzig, A.; Scolieri, G.; Seo, E. S.; Shan, B. S.; Shi, J. Y.; Shi, Y. M.; Siedenburg, T.; Siedling, R.; Son, D.; Spada, F.; Spinella, F.; Steuer, M.; Stiff, K.; Sun, W.; Sun, W. H.; Sun, X. H.; Tacconi, M.; Tang, C. P.; Tang, X. W.; Tang, Z. C.; Tao, L.; Tassan-Viol, J.; Ting, Samuel C. C.; Ting, S. M.; Titus, C.; Tomassetti, N.; Toral, F.; Torsti, J.; Tsai, J. R.; Tutt, J. C.; Ulbricht, J.; Urban, T.; Vagelli, V.; Valente, E.; Vannini, C.; Valtonen, E.; Vargas Trevino, M.; Vaurynovich, S.; Vecchi, M.; Vergain, M.; Verlaat, B.; Vescovi, C.; Vialle, J. P.; Viertel, G.; Volpini, G.; Wang, D.; Wang, N. H.; Wang, Q. L.; Wang, R. S.; Wang, X.; Wang, Z. X.; Wallraff, W.; Weng, Z. L.; Willenbrock, M.; Wlochal, M.; Wu, H.; Wu, K. Y.; Wu, Z. S.; Xiao, W. J.; Xie, S.; Xiong, R. Q.; Xin, G. M.; Xu, N. S.; Xu, W.; Yan, Q.; Yang, J.; Yang, M.; Ye, Q. H.; Yi, H.; Yu, Y. J.; Yu, Z. Q.; Zeissler, S.; Zhang, J. G.; Zhang, Z.; Zhang, M. M.; Zheng, Z. M.; Zhuang, H. L.; Zhukov, V.; Zichichi, A.; Zuccon, P.; Zurbach, C.

    2013-04-01

    A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8×106 positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to ˜250GeV, but, from 20 to 250 GeV, the slope decreases by an order of magnitude. The positron fraction spectrum shows no fine structure, and the positron to electron ratio shows no observable anisotropy. Together, these features show the existence of new physical phenomena.

  20. Design and characterization of a pulsed x-ray source for fluorescent lifetime measurements

    SciTech Connect

    Blankespoor, S.C. [Univ. of California, Berkeley, CA (United States). Dept. of Electrical Engineering and Computer Science]|[Lawrence Berkeley Lab., CA (United States)

    1993-12-01

    To search for new, fast, inorganic scintillators, the author and his colleagues have developed a bench-top pulsed x-ray source for determining fluorescent lifetimes and wavelengths of compounds in crystal or powdered form. This source uses a light-excited x-ray tube which produces x-rays when light from a laser diode strikes its photocathode. The x-ray tube has a tungsten anode, a beryllium exit window, a 30 kV maximum tube bias, and a 50 HA maximum average cathode current. The laser produces 3 {times} 10{sup 7} photons at 650 nm per {approximately}100 ps pulse, with up to 10{sup 7} pulses/sec. The time spread for the laser diode, x-ray tube, and a microchannel plate photomultiplier tube is less than 120 ps fwhm. The mean x-ray photon energy, at tube biases of 20, 25, and 30 kV, is 9.4, 10.3, and 11.1 keV, respectively. They measured 140, 230, and 330 x-ray photons per laser diode pulse per steradian at tube biases of 20, 25, and 30 kV, respectively. Background x-rays due to dark current occur at a rate of 1 {times} 10{sup 6} and 3 {times} 10{sup 6} photons/sec/steradian at tube biases of 25 and 30 kV, respectively. Data characterizing the x-ray output with an aluminum filter in the x-ray beam are also presented.

  1. Thermal evolution of boron irradiation induced defects in predoped Si revealed by positron annihilation experiments

    NASA Astrophysics Data System (ADS)

    Nambissan, P. M. G.; Bhagwat, P. V.; Kurup, M. B.

    2007-06-01

    The isochronal annealing behavior of high energy (25-72 MeV) boron ion irradiation induced defects in boron-doped silicon is monitored through measurements of positron lifetimes and three distinct defect-evolution stages are identified. The initial boron doping created a defect environment where positrons could sensitively annihilate with the boron electrons, suggesting boron-decorated Si monovacancies as potential trapping sites. The irradiation results in the dissolution of boron from these sites and positrons are then trapped by the empty divacancies of Si. Charge neutralization of divacancies through interaction with boron atoms leads to enhanced positron trapping in the initial stages of isochronal annealing. The divacancies start annealing above 673 K. However, a remarkable defect evolution stage due to the diffusion of the boron atoms beyond their initial depths of penetration is seen above 873 K and it leaves the sample with defects still present even at the highest annealing temperature 1273 K used in this work.

  2. Positron annihilation in germanium

    Microsoft Academic Search

    M. A. Shulman; G. M. Beardsley; S. Berko

    1975-01-01

    High precision long-slit and cross-slit geometry angular distributions of annihilation radiation from oriented germanium are\\u000a presented. The momentum distributions from the long-slit measurements are compared with recent Compton profile data to test\\u000a the importance of the positron wavefunction and positron-electron correlations. Evidence for Umklapp annihilation is discussed.\\u000a No observable differences are found between distributions from heavily doped and intrinsic germanium

  3. Plans for a measurement of the neutron lifetime to better than 0.3s using a Penning trap and absolute measurement of neutron fluence

    NASA Astrophysics Data System (ADS)

    Mulholland, Jonathan; NBL3 Collaboration

    2014-09-01

    The decay of the free neutron is the prototypical charged current semi-leptonic weak process. A precise value for the neutron lifetime is required for consistency tests of the Standard Model and is needed to predict the primordial He4 abundance from the theory of Big Bang Nucleosynthesis. Plans are being made for an in-beam measurement of the neutron lifetime with an anticipated 0.3s of uncertainty or better. This effort is part of a phased campaign of neutron lifetime measurements based at the NIST Center for Neutron Research, using the Sussex-ILL-NIST technique. Advances in neutron fluence measurement, used in to provide the best existing in-beam determination of the neutron lifetime, as well as new silicon detector technology, in use now at LANSCE, address the two largest contributors to the uncertainty of in-beam measurements-the statistical uncertainty associated with proton counting and the systematic uncertainty in the neutron fluence measurement. The experimental design and projected uncertainties for the 0.3s measurement will be discussed.

  4. Possible Systematic Effects in Fomblin Coated Storage Cell Neutron Lifetime Measurements

    E-print Network

    Steve K. Lamoreaux

    2008-04-08

    A new neutron lifetime experiment employing frozen Fomblin has produced a result in significant disagreement with previous experiments that used liquid Fomblin near room temperature. This new experiment is subject to very few corrections, so the source of the discrepancy is a mystery. Here we theoretically investigate several possible systematic effects for near-room-temperature storage experiments. By considering the combined effect of gravity with the usual ultracold neutron losses together with surface wave scattering loss and ultracold spectral evoltuion, a correction to a previous neutron lifetime experiment is found to be insignificantly small.

  5. Oxygen distribution and vascular injury in the mouse eye measured by phosphorescence-lifetime imaging

    PubMed Central

    Wilson, David F.; Vinogradov, Sergei A.; Grosul, Pavel; Vaccarezza, M. Noel; Kuroki, Akiko; Bennett, Jean

    2009-01-01

    Maps of the oxygen distribution in the retina of the mouse eye were obtained by phosphorescence-lifetime imaging. Phosphor dissolved in the blood was excited by modulated light and phosphorescence imaged through microscope optics with an intensified-CCD camera. Phosphorescence lifetimes and oxygen pressures were calculated for each pixel of the images. The resolution was sufficient to permit the detection of anomalies that result in reduced oxygen pressures in individual retinal capillaries. High-resolution maps of oxygen distribution in the retina can provide greater understanding of the role of oxygen and vascular function in diseases of the eye. PMID:16149347

  6. Positron annihilation on defects in silicon irradiated with 15 MeV protons

    NASA Astrophysics Data System (ADS)

    Arutyunov, N. Y.; Elsayed, M.; Krause-Rehberg, R.; Emtsev, V. V.; Oganesyan, G. A.; Kozlovski, V. V.

    2013-01-01

    Microstructure and thermal stability of the radiation defects in n-FZ-Si ([P] ? 7 × 1015 cm-3) single crystals have been investigated. The radiation defects have been induced by irradiation with 15 MeV protons and studied by means of both the positron lifetime spectroscopy and low-temperature measurements of the Hall effect. At each step of the isochronal annealing over the temperature range ˜60-700?°C the positron lifetime has been measured for the temperature interval ˜30-300 K, and for samples-satellites the temperature dependences of the charge carriers and mobility have been determined over the range ˜4.2-300 K. It is argued that as-grown impurity centers influence the average positron lifetime by forming shallow (Eb ? 0.013 eV) positron states. The radiation-induced defects were also found to trap positrons into weakly bound (Eb ? 0.01 eV) states. These positron states are observed at cryogenic temperatures during the isochronal annealing up to Tanneal. = 340?°C. The stages of annealing in the temperature intervals ˜60-180?°C and ˜180-260?°C reflect the disappearance of E-centers and divacancies, respectively. Besides these defects the positrons were found to be localized at deep donor centers hidden in the process of annealing up to the temperature Tanneal. ? 300?°C. The annealing of the deep donors occurs over the temperature range ˜300-650?°C. At these centers positrons are estimated to be bound with energies Eb ? 0.096 and 0.021 eV within the temperature intervals ˜200-270 K and ˜166-66 K, respectively. The positron trapping coefficient from these defects increases from ˜1.1 × 1016 to ˜6.5 × 1017 s-1 over the temperature range ˜266-66 K, thus substantiating a cascade phonon-assisted positron trapping mechanism whose efficiency is described by ?T-3 law. It is argued that the value of activation energy of the isochronal annealing Ea ? 0.74-0.59 eV is due to dissociation of the positron traps, which is accompanied by restoration of the electrical activity of the phosphorus atoms. The data suggest that the deep donors involve a phosphorus atom and at least two vacancies. Their energy levels are at least at E > Ec - 0.24 eV in the investigated material.

  7. Total cross sections for positrons scattered elastically from helium based on new measurements of total ionization cross sections

    NASA Technical Reports Server (NTRS)

    Diana, L. M.; Chaplin, R. L.; Brooks, D. L.; Adams, J. T.; Reyna, L. K.

    1990-01-01

    An improved technique is presented for employing the 2.3m spectrometer to measure total ionization cross sections, Q sub ion, for positrons incident on He. The new ionization cross section agree with the values reported earlier. Estimates are also presented of total elastic scattering cross section, Q sub el, obtained by subtracting from total scattering cross sections, Q sub tot, reported in the literature, the Q sub ion and Q sub Ps (total positronium formation cross sections) and total excitation cross sections, Q sub ex, published by another researcher. The Q sub ion and Q sub el measured with the 3m high resolution time-of-flight spectrometer for 54.9eV positrons are in accord with the results from the 2.3m spectrometer. The ionization cross sections are in fair agreement with theory tending for the most part to be higher, especially at 76.3 and 88.5eV. The elastic cross section agree quite well with theory to the vicinity of 50eV, but at 60eV and above the experimental elastic cross sections climb to and remain at about 0.30 pi a sub o sq while the theoretical values steadily decrease.

  8. Method and apparatus for measuring minority carrier lifetimes and bulk diffusion length in P-N junction solar cells

    NASA Technical Reports Server (NTRS)

    Vonroos, O. H. (inventor)

    1978-01-01

    Carrier lifetimes and bulk diffusion length are qualitatively measured as a means for qualification of a P-N junction photovoltaic solar cell. High frequency (blue) monochromatic light pulses and low-frequency (red) monochromatic light pulses were alternately applied to the cell while it was irradiated by light from a solar simulator, and synchronously displaying the derivative of the output voltage of the cell on an oscilloscope. The output voltage is a measure of the lifetimes of the minority carriers (holes) in the diffused N layer and majority carriers (electrons) in the bulk P material, and of the diffusion length of the bulk silicon. By connecting a reference cell in this manner with a test cell to be tested in reverse parallel, the display of a test cell that matches the reference cell will be a substantially zero output.

  9. Microstructural evolution of ZnS during sintering monitored by optical and positron annihilation techniques

    NASA Astrophysics Data System (ADS)

    Adams, M.; Mascher, P.; Kitai, A. H.

    1995-07-01

    Positron lifetime and optical absorption techniques were employed to track the microstructural evolution of polycrystalline ZnS grown by Chemical Vapor Deposition (CVD). As grown material and material treated with Hot Isostatic Pressure (HIP) was sintered at temperatures ranging from 400 to 1000 °C for 2 18 h. A 290 ps defect lifetime could be resolved in all samples, while an additional longer lifetime (?=430 ps) was found only in samples annealed at low temperatures. This component gradually disappeared during annealing at 800 ° C. Associated with the disappearance of the long-lived component, the apparent bulk lifetime of the material changed from 235 to 215 ps. A 215±2 ps bulk parameter was also found for HIP-treated material annealed at temperatures greater than 400 ° C and hence is taken to represent the delocalized state of the positrons in ZnS. Optical absorption measurements showed that annealing at 800 ° C also caused the absorption profiles of the CVD and HIP samples to converge. The rate of the bulk lifetime transition correlates with the absorption changes. The observed sharpening of the absorption profile is attributed to a decrease in scattering from grain boundaries and voids, and a decrease in absorption from point defects. The 430 ps lifetime is believed to be due to trapping at voids and grain boundaries, while the 290 ps lifetime likely is due to a monovacancy stabilized as a small complex.

  10. MICROWAVE NOISE TECHNIQUE FOR MEASUREMENT OF HOT-ELECTRON ENERGY RELAXATION TIME AND HOT-PHONON LIFETIME

    Microsoft Academic Search

    J. Liberis; A. Matulionis

    Gated modulation-type radiometric technique for microwave noise measurement is upgraded for convenient investigation of hot-electron energy relaxation and hot-phonon dynamics in a channel with a high-density electron gas. The technique is applied to a GaN-based structure held at 80 and 293 K channel temperature. The results are discussed in terms of hot-phonon effect on hot-electron energy relaxation. The hot-phonon lifetime,

  11. Measurement of the Lambda0b Lifetime in the Decay Lambda0b-->J\\/psiLambda0 with the D0 Detector

    Microsoft Academic Search

    V. M. Abazov; B. Abbott; M. Abolins; B. S. Acharya; M. Adams; T. Adams; M. Agelou; J.-L. Agram; S. H. Ahn; M. Ahsan; G. D. Alexeev; G. Alkhazov; A. Alton; G. Alverson; G. A. Alves; M. Anastasoaie; S. Anderson; B. Andrieu; Y. Arnoud; A. Askew; B. Åsman; O. Atramentov; C. Autermann; C. Avila; F. Badaud; A. Baden; B. Baldin; P. W. Balm; S. Banerjee; E. Barberis; P. Bargassa; P. Baringer; C. Barnes; J. Barreto; J. F. Bartlett; U. Bassler; D. Bauer; A. Bean; S. Beauceron; M. Begel; A. Bellavance; S. B. Beri; G. Bernardi; R. Bernhard; I. Bertram; M. Besançon; R. Beuselinck; V. A. Bezzubov; P. C. Bhat; V. Bhatnagar; M. Binder; K. M. Black; I. Blackler; G. Blazey; F. Blekman; S. Blessing; D. Bloch; U. Blumenschein; A. Boehnlein; O. Boeriu; T. A. Bolton; F. Borcherding; G. Borissov; K. Bos; T. Bose; A. Brandt; R. Brock; G. Brooijmans; A. Bross; N. J. Buchanan; D. Buchholz; M. Buehler; V. Buescher; S. Burdin; T. H. Burnett; E. Busato; J. M. Butler; J. Bystricky; W. Carvalho; B. C. Casey; N. M. Cason; H. Castilla-Valdez; S. Chakrabarti; D. Chakraborty; K. M. Chan; A. Chandra; D. Chapin; F. Charles; E. Cheu; L. Chevalier; D. K. Cho; S. Choi; T. Christiansen; L. Christofek; D. Claes; B. Clément; C. Clément; Y. Coadou; M. Cooke; W. E. Cooper; D. Coppage; M. Corcoran; J. Coss; A. Cothenet; M.-C. Cousinou; S. Crépé-Renaudin; M. Cristetiu; M. A. Cummings; D. Cutts; H. da Motta; B. Davies; G. Davies; G. A. Davis; K. de; P. de Jong; S. J. de Jong; E. de La Cruz-Burelo; C. de Oliveira Martins; S. Dean; F. Déliot; P. A. Delsart; M. Demarteau; R. Demina; P. Demine; D. Denisov; S. P. Denisov; S. Desai; H. T. Diehl; M. Diesburg; M. Doidge; H. Dong; S. Doulas; L. Duflot; S. R. Dugad; A. Duperrin; J. Dyer; A. Dyshkant; M. Eads; D. Edmunds; T. Edwards; J. Ellison; J. Elmsheuser; J. T. Eltzroth; V. D. Elvira; S. Eno; P. Ermolov; O. V. Eroshin; J. Estrada; D. Evans; H. Evans; A. Evdokimov; V. N. Evdokimov; J. Fast; S. N. Fatakia; L. Feligioni; T. Ferbel; F. Fiedler; F. Filthaut; W. Fisher; H. E. Fisk; M. Fortner; H. Fox; W. Freeman; S. Fu; S. Fuess; T. Gadfort; C. F. Galea; E. Gallas; E. Galyaev; C. Garcia; A. Garcia-Bellido; J. Gardner; V. Gavrilov; P. Gay; D. Gelé; R. Gelhaus; K. Genser; C. E. Gerber; Y. Gershtein; G. Ginther; T. Golling; B. Gómez; K. Gounder; A. Goussiou; P. D. Grannis; S. Greder; H. Greenlee; Z. D. Greenwood; E. M. Gregores; Ph. Gris; J.-F. Grivaz; L. Groer; S. Grünendahl; M. W. Grünewald; S. N. Gurzhiev; G. Gutierrez; P. Gutierrez; A. Haas; N. J. Hadley; S. Hagopian; I. Hall; R. E. Hall; C. Han; L. Han; K. Hanagaki; K. Harder; R. Harrington; J. M. Hauptman; R. Hauser; J. Hays; T. Hebbeker; D. Hedin; J. M. Heinmiller; A. P. Heinson; U. Heintz; C. Hensel; G. Hesketh; M. D. Hildreth; R. Hirosky; J. D. Hobbs; B. Hoeneisen; M. Hohlfeld; S. J. Hong; R. Hooper; P. Houben; Y. Hu; J. Huang; I. Iashvili; R. Illingworth; A. S. Ito; S. Jabeen; M. Jaffré; S. Jain; V. Jain; K. Jakobs; A. Jenkins; R. Jesik; K. Johns; M. Johnson; A. Jonckheere; P. Jonsson; H. Jöstlein; A. Juste; M. M. Kado; D. Käfer; W. Kahl; S. Kahn; E. Kajfasz; A. M. Kalinin; J. Kalk; D. Karmanov; J. Kasper; D. Kau; R. Kehoe; S. Kermiche; S. Kesisoglou; A. Khanov; A. Kharchilava; Y. M. Kharzheev; K. H. Kim; B. Klima; M. Klute; J. M. Kohli; M. Kopal; V. M. Korablev; J. Kotcher; B. Kothari; A. Koubarovsky; A. V. Kozelov; J. Kozminski; S. Krzywdzinski; S. Kuleshov; Y. Kulik; S. Kunori; A. Kupco; T. Kurca; S. Lager; N. Lahrichi; G. Landsberg; J. Lazoflores; A.-C. Le Bihan; P. Lebrun; S. W. Lee; W. M. Lee; A. Leflat; F. Lehner; C. Leonidopoulos; P. Lewis; J. Li; Q. Z. Li; J. G. Lima; D. Lincoln; S. L. Linn; J. Linnemann; V. V. Lipaev; R. Lipton; L. Lobo; A. Lobodenko; M. Lokajicek; A. Lounis; H. J. Lubatti; L. Lueking; M. Lynker; A. L. Lyon; A. K. Maciel; R. J. Madaras; P. Mättig; A. Magerkurth; A.-M. Magnan; N. Makovec; P. K. Mal; S. Malik; V. L. Malyshev; H. S. Mao; Y. Maravin; M. Martens; S. E. Mattingly; A. A. Mayorov; R. McCarthy; R. McCroskey; D. Meder; H. L. Melanson; A. Melnitchouk; M. Merkin; K. W. Merritt; A. Meyer; H. Miettinen; D. Mihalcea; J. Mitrevski; N. Mokhov; J. Molina; N. K. Mondal; H. E. Montgomery; R. W. Moore; G. S. Muanza; M. Mulders; Y. D. Mutaf; E. Nagy; M. Narain; N. A. Naumann; H. A. Neal; J. P. Negret; S. Nelson; P. Neustroev; C. Noeding; A. Nomerotski; S. F. Novaes; T. Nunnemann; E. Nurse; V. O'dell; D. C. O'Neil; V. Oguri; N. Oliveira; N. Oshima; G. J. Otero Y Garzón; P. Padley; N. Parashar; S. K. Park; J. Parsons; R. Partridge; N. Parua; A. Patwa; P. M. Perea; E. Perez; O. Peters; P. Pétroff; M. Petteni; L. Phaf; R. Piegaia; P. L. Podesta-Lerma; V. M. Podstavkov; Y. Pogorelov; B. G. Pope; W. L. Prado da Silva; H. B. Prosper; S. Protopopescu; M. B. Przybycien; J. Qian; A. Quadt; B. Quinn; K. J. Rani; P. A. Rapidis; P. N. Ratoff; N. W. Reay; S. Reucroft; M. Rijssenbeek; I. Ripp-Baudot

    2005-01-01

    We present measurements of the Lambda0b lifetime in the exclusive decay channel Lambda0b-->J\\/psiLambda0, with J\\/psi-->mu+mu- and Lambda0-->ppi-, the B0 lifetime in the decay B0-->J\\/psiK0S with J\\/psi-->mu+mu- and K0S-->pi+pi-, and the ratio of these lifetimes. The analysis is based on approximately 250 pb-1 of data recorded with the D0 detector in pp¯ collisions at &surd;(s)=1.96 TeV. The Lambda0b lifetime is determined

  12. Alternative Size and Lifetime Measurements for High-Energy Heavy-Ion Collisions

    E-print Network

    Scott Pratt; Silvio Petriconi

    2003-06-16

    Two-Particle correlations based on the interference of identical particles has provided the chief means for determining the shape and lifetime of sources in relativistic heavy ion collisions. Here, Strong and Coulomb induced correlations are shown to provide equivalent information.

  13. Characterization of aSi:H\\/cSi interfaces by effective-lifetime measurements

    Microsoft Academic Search

    M. Garín; U. Rau; W. Brendle; I. Martín; R. Alcubilla

    2005-01-01

    This article studies theoretically and experimentally the recombination at the amorphous\\/crystalline silicon interface of a heterojunction with intrinsic thin layer (HIT) structure without metallization. We propose a physical model to calculate the interface recombination rate under illumination. This model calculates the effective lifetime taueff as a function of the average excess minority carrier concentration . In order to test the

  14. Measuring OH Reaction Rate Constants and Estimating the Atmospheric Lifetimes of Trace Gases.

    NASA Astrophysics Data System (ADS)

    Orkin, Vladimir; Kurylo, Michael

    2015-04-01

    Reactions with hydroxyl radicals and photolysis are the main processes dictating a compound's residence time in the atmosphere for a majority of trace gases. In case of very short-lived halocarbons their reaction with OH dictates both the atmospheric lifetime and active halogen release. Therefore, the accuracy of OH kinetic data is of primary importance for the comprehensive modeling of a compound's impact on the atmosphere, such as in ozone depletion (i.e., the Ozone Depletion Potential, ODP) and climate change (i.e., the Global Warming Potential, GWP), each of which are dependent on the atmospheric lifetime of the compound. We have demonstrated the ability to conduct very high accuracy determinations of OH reaction rate constants over the temperature range of atmospheric interest, thereby decreasing the uncertainty of kinetic data to 2-3%. The atmospheric lifetime of a well-mixed compound due to its reaction with tropospheric hydroxyl radicals can be estimated by using a simple scaling procedure that is based on the results of field observations of methyl chloroform concentrations and detailed modeling of the OH distribution in the atmosphere. The currently available modeling results of the atmospheric fate of various trace gases allow for an improved understanding of the ability and accuracy of simplified semi-empirical estimations of atmospheric lifetimes. These aspects will be illustrated in this presentation for a variety of atmospheric trace gases.

  15. Near Infrared Dyes as Lifetime Solvatochromic Probes for Micropolarity Measurements of Biological Systems

    E-print Network

    Larson-Prior, Linda

    in solvents with diverse polarity, their fluorescence lifetimes are highly sensitive, increasing by a factor for determining the polarity of complex systems, including micelles and albumin binding sites. Because Systems Mikhail Y. Berezin, Hyeran Lee, Walter Akers, and Samuel Achilefu Department of Radiology

  16. High Statistics Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5-500 GeV with the Alpha Magnetic Spectrometer on the International Space Station

    NASA Astrophysics Data System (ADS)

    Accardo, L.; Aguilar, M.; Aisa, D.; Alvino, A.; Ambrosi, G.; Andeen, K.; Arruda, L.; Attig, N.; Azzarello, P.; Bachlechner, A.; Barao, F.; Barrau, A.; Barrin, L.; Bartoloni, A.; Basara, L.; Battarbee, M.; Battiston, R.; Bazo, J.; Becker, U.; Behlmann, M.; Beischer, B.; Berdugo, J.; Bertucci, B.; Bigongiari, G.; Bindi, V.; Bizzaglia, S.; Bizzarri, M.; Boella, G.; de Boer, W.; Bollweg, K.; Bonnivard, V.; Borgia, B.; Borsini, S.; Boschini, M. J.; Bourquin, M.; Burger, J.; Cadoux, F.; Cai, X. D.; Capell, M.; Caroff, S.; Casaus, J.; Cascioli, V.; Castellini, G.; Cernuda, I.; Cervelli, F.; Chae, M. J.; Chang, Y. H.; Chen, A. I.; Chen, H.; Cheng, G. M.; Chen, H. S.; Cheng, L.; Chikanian, A.; Chou, H. Y.; Choumilov, E.; Choutko, V.; Chung, C. H.; Clark, C.; Clavero, R.; Coignet, G.; Consolandi, C.; Contin, A.; Corti, C.; Coste, B.; Cui, Z.; Dai, M.; Delgado, C.; Della Torre, S.; Demirköz, M. B.; Derome, L.; Di Falco, S.; Di Masso, L.; Dimiccoli, F.; Díaz, C.; von Doetinchem, P.; Du, W. J.; Duranti, M.; D'Urso, D.; Eline, A.; Eppling, F. J.; Eronen, T.; Fan, Y. Y.; Farnesini, L.; Feng, J.; Fiandrini, E.; Fiasson, A.; Finch, E.; Fisher, P.; Galaktionov, Y.; Gallucci, G.; García, B.; García-López, R.; Gast, H.; Gebauer, I.; Gervasi, M.; Ghelfi, A.; Gillard, W.; Giovacchini, F.; Goglov, P.; Gong, J.; Goy, C.; Grabski, V.; Grandi, D.; Graziani, M.; Guandalini, C.; Guerri, I.; Guo, K. H.; Habiby, M.; Haino, S.; Han, K. C.; He, Z. H.; Heil, M.; Hoffman, J.; Hsieh, T. H.; Huang, Z. C.; Huh, C.; Incagli, M.; Ionica, M.; Jang, W. Y.; Jinchi, H.; Kanishev, K.; Kim, G. N.; Kim, K. S.; Kirn, Th.; Kossakowski, R.; Kounina, O.; Kounine, A.; Koutsenko, V.; Krafczyk, M. S.; Kunz, S.; La Vacca, G.; Laudi, E.; Laurenti, G.; Lazzizzera, I.; Lebedev, A.; Lee, H. T.; Lee, S. C.; Leluc, C.; Li, H. L.; Li, J. Q.; Li, Q.; Li, Q.; Li, T. X.; Li, W.; Li, Y.; Li, Z. H.; Li, Z. Y.; Lim, S.; Lin, C. H.; Lipari, P.; Lippert, T.; Liu, D.; Liu, H.; Lomtadze, T.; Lu, M. J.; Lu, Y. S.; Luebelsmeyer, K.; Luo, F.; Luo, J. Z.; Lv, S. S.; Majka, R.; Malinin, A.; Mañá, C.; Marín, J.; Martin, T.; Martínez, G.; Masi, N.; Maurin, D.; Menchaca-Rocha, A.; Meng, Q.; Mo, D. C.; Morescalchi, L.; Mott, P.; Müller, M.; Ni, J. Q.; Nikonov, N.; Nozzoli, F.; Nunes, P.; Obermeier, A.; Oliva, A.; Orcinha, M.; Palmonari, F.; Palomares, C.; Paniccia, M.; Papi, A.; Pedreschi, E.; Pensotti, S.; Pereira, R.; Pilo, F.; Piluso, A.; Pizzolotto, C.; Plyaskin, V.; Pohl, M.; Poireau, V.; Postaci, E.; Putze, A.; Quadrani, L.; Qi, X. M.; Rancoita, P. G.; Rapin, D.; Ricol, J. S.; Rodríguez, I.; Rosier-Lees, S.; Rozhkov, A.; Rozza, D.; Sagdeev, R.; Sandweiss, J.; Saouter, P.; Sbarra, C.; Schael, S.; Schmidt, S. M.; Schuckardt, D.; von Dratzig, A. Schulz; Schwering, G.; Scolieri, G.; Seo, E. S.; Shan, B. S.; Shan, Y. H.; Shi, J. Y.; Shi, X. Y.; Shi, Y. M.; Siedenburg, T.; Son, D.; Spada, F.; Spinella, F.; Sun, W.; Sun, W. H.; Tacconi, M.; Tang, C. P.; Tang, X. W.; Tang, Z. C.; Tao, L.; Tescaro, D.; Ting, Samuel C. C.; Ting, S. M.; Tomassetti, N.; Torsti, J.; Türko?lu, C.; Urban, T.; Vagelli, V.; Valente, E.; Vannini, C.; Valtonen, E.; Vaurynovich, S.; Vecchi, M.; Velasco, M.; Vialle, J. P.; Wang, L. Q.; Wang, Q. L.; Wang, R. S.; Wang, X.; Wang, Z. X.; Weng, Z. L.; Whitman, K.; Wienkenhöver, J.; Wu, H.; Xia, X.; Xie, M.; Xie, S.; Xiong, R. Q.; Xin, G. M.; Xu, N. S.; Xu, W.; Yan, Q.; Yang, J.; Yang, M.; Ye, Q. H.; Yi, H.; Yu, Y. J.; Yu, Z. Q.; Zeissler, S.; Zhang, J. H.; Zhang, M. T.; Zhang, X. B.; Zhang, Z.; Zheng, Z. M.; Zhuang, H. L.; Zhukov, V.; Zichichi, A.; Zimmermann, N.; Zuccon, P.; Zurbach, C.; AMS Collaboration

    2014-09-01

    A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy range of our previous observation and increases its precision. The new results show, for the first time, that above ?200 GeV the positron fraction no longer exhibits an increase with energy.

  17. GENETIC PARAMETERS FOR SIX MEASURES OF LENGTH OF PRODUCTIVE LIFE AND THREE MEASURES OF LIFETIME PRODUCTION BY SIX YEARS AFTER FIRST CALVING FOR HEREFORD COWS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic parameters for length of productive life given the opportunity (LPL|O), measured as days between first calving and disposal conditioned on one of six opportunity groups, (e.g., L2 is length of productive life in days given the opportunity to live 2 yr after first calving), and lifetime produ...

  18. Microstructure of thermally grown and deposited alumina films probed with positrons

    SciTech Connect

    Somieski, B.; Hulett, L.D.; Xu, J. [Oak Ridge National Laboratory, Chemical Analytical Sciences Division, Oak Ridge, Tennessee 37831 (United States)] [Oak Ridge National Laboratory, Chemical Analytical Sciences Division, Oak Ridge, Tennessee 37831 (United States); Pint, B.A.; Tortorelli, P.F. [Oak Ridge National Laboratory, Metals Ceramics Division, Oak Ridge, Tennessee 37831 (United States)] [Oak Ridge National Laboratory, Metals Ceramics Division, Oak Ridge, Tennessee 37831 (United States); Nielsen, B.; Asoka-Kumar, P. [Brookhaven National Laboratory, Department of Physics, Upton, New York 11973 (United States)] [Brookhaven National Laboratory, Department of Physics, Upton, New York 11973 (United States); Suzuki, R.; Ohdaira, T. [Electrotechnical Laboratory, Quantum Radiation Division, Tsukuba, Ibaraki 305 (Japan)] [Electrotechnical Laboratory, Quantum Radiation Division, Tsukuba, Ibaraki 305 (Japan)

    1999-03-01

    Aluminum oxide films used for corrosion protection of iron and nickel aluminides were generated by substrate oxidation as well as plasma and physical vapor depositions. The films grown by oxidation were crystalline. The others were amorphous. Defect structures of the films were studied by positron spectroscopy techniques. Lifetimes of the positrons, and Doppler broadening of the {gamma} photons generated by their annihilation, were measured as functions of the energies with which they were injected. In this manner, densities and sizes of the defects were determined as functions of depths from the outer surfaces of the films. Alumina films generated by oxidation had high densities of open volume defects, mainly consisting of a few aggregated vacancies. In the outer regions of the films the structures of the defects did not depend on substrate compositions. Positron lifetime measurements, and the {ital S} and {ital W} parameters extracted from Doppler broadening spectra, showed uniform distributions of defects in the crystalline Al{sub 2}O{sub 3} films grown on nickel aluminide substrates, but these data indicated intermediate layers of higher defect contents at the film/substrate interfaces of oxides grown on iron aluminide substrates. Amorphous films generated by plasma and physical vapor deposition had much larger open volume defects, which caused the average lifetimes of the injected positrons to be significantly longer. The plasma deposited film exhibited a high density of large cavities. {copyright} {ital 1999} {ital The American Physical Society}

  19. Measurement of the ?b? lifetime in the exclusive decay ?b??J/??? in pp? collisions at ?s=1.96 TeV

    DOE PAGESBeta

    Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Aoki, M.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Bose, T.; Brandt, A.; Brandt, O.; Brock, R.; Brooijmans, G.; Bross, A.; Brown, D.; Brown, J.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Pérez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chakraborty, D.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Chevalier-Théry, S.; Cho, D. K.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Croc, A.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duggan, D.; Duperrin, A.; Dutt, S.; Dyshkant, A.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Facini, G.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garcia-Bellido, A.; García-González, J. A.; García-Guerra, G. A.; Gavrilov, V.; Gay, P.; Geng, W.; Gerbaudo, D.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Golovanov, G.; Goussiou, A.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haas, A.; Hagopian, S.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hohlfeld, M.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jayasinghe, A.; Jesik, R.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kaadze, K.; Kajfasz, E.; Karmanov, D.; Kasper, P. A.; Katsanos, I.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kulikov, S.; Kumar, A.; Kupco, A.; Kur?a, T.; Kuzmin, V. A.; Lammers, S.; Landsberg, G.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lellouch, J.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Lubatti, H. J.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Maravin, Y.; Martínez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Mulhearn, M.; Nagy, E.; Naimuddin, M.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nunnemann, T.; Obrant, G.; Orduna, J.; Osman, N.; Osta, J.; Padilla, M.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Pleier, M.-A.; Podesta-Lerma, P. L. M.; Podstavkov, V. M.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Rangel, M. S.; Ranjan, K.; Ratoff, P. N.; Razumov, I.; Renkel, P.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Salcido, P.; Sánchez-Hernández, A.; Sanders, M. P.; Sanghi, B.; Santos, A. S.; Savage, G.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schlobohm, S.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shaw, S.; Shchukin, A. A.; Shivpuri, R. K.; Simak, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Smith, K. J.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.; Stoyanova, D. A.; Strauss, M.; Stutte, L.; Suter, L.; Svoisky, P.; Takahashi, M.; Titov, M.; Tokmenin, V. V.; Tsai, Y.-T.; Tschann-Grimm, K.; Tsybychev, D.; Tuchming, B.; Tully, C.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.

    2012-06-01

    We measure the ??b lifetime in the fully reconstructed decay ??b?J/??? using 10.4 fb?¹ of pp? collisions collected with the D0 detector at ?s=1.96 TeV. The lifetime of the topologically similar decay channel B??J/?K?S is also measured. We obtain ?(??b)=1.303±0.075(stat)±0.035(syst) ps and ?(B?)=1.508±0.025(stat)±0.043(syst) ps. Using these measurements, we determine the lifetime ratio of ?(??b)/?(B?)=0.864±0.052(stat)±0.033(syst).

  20. Measurement of the ?b? lifetime in the exclusive decay ?b??J/??? in pp? collisions at ?s=1.96 TeV

    SciTech Connect

    Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Aoki, M.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Bose, T.; Brandt, A.; Brandt, O.; Brock, R.; Brooijmans, G.; Bross, A.; Brown, D.; Brown, J.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Pérez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chakraborty, D.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Chevalier-Théry, S.; Cho, D. K.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Croc, A.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duggan, D.; Duperrin, A.; Dutt, S.; Dyshkant, A.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Facini, G.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garcia-Bellido, A.; García-González, J. A.; García-Guerra, G. A.; Gavrilov, V.; Gay, P.; Geng, W.; Gerbaudo, D.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Golovanov, G.; Goussiou, A.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haas, A.; Hagopian, S.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hohlfeld, M.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jayasinghe, A.; Jesik, R.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kaadze, K.; Kajfasz, E.; Karmanov, D.; Kasper, P. A.; Katsanos, I.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kulikov, S.; Kumar, A.; Kupco, A.; Kur?a, T.; Kuzmin, V. A.; Lammers, S.; Landsberg, G.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lellouch, J.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Lubatti, H. J.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Maravin, Y.; Martínez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Mulhearn, M.; Nagy, E.; Naimuddin, M.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nunnemann, T.; Obrant, G.; Orduna, J.; Osman, N.; Osta, J.; Padilla, M.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Pleier, M.-A.; Podesta-Lerma, P. L. M.; Podstavkov, V. M.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Rangel, M. S.; Ranjan, K.; Ratoff, P. N.; Razumov, I.; Renkel, P.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Salcido, P.; Sánchez-Hernández, A.; Sanders, M. P.; Sanghi, B.; Santos, A. S.; Savage, G.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schlobohm, S.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shaw, S.; Shchukin, A. A.; Shivpuri, R. K.; Simak, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Smith, K. J.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.; Stoyanova, D. A.; Strauss, M.; Stutte, L.; Suter, L.; Svoisky, P.; Takahashi, M.; Titov, M.; Tokmenin, V. V.; Tsai, Y.-T.; Tschann-Grimm, K.; Tsybychev, D.; Tuchming, B.; Tully, C.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.

    2012-06-01

    We measure the ??b lifetime in the fully reconstructed decay ??b?J/??? using 10.4 fb?¹ of pp? collisions collected with the D0 detector at ?s=1.96 TeV. The lifetime of the topologically similar decay channel B??J/?K?S is also measured. We obtain ?(??b)=1.303±0.075(stat)±0.035(syst) ps and ?(B?)=1.508±0.025(stat)±0.043(syst) ps. Using these measurements, we determine the lifetime ratio of ?(??b)/?(B?)=0.864±0.052(stat)±0.033(syst).

  1. Characterization of arachidate Langmuir--Blodgett films by variable energy positron beams

    SciTech Connect

    Marek, T.; Szeles, C.; Suvegh, K.; Kiss, E.; Vertes, A.; Lynn, K.G.

    1999-11-09

    Archidate Langmuir-Blodgett (LB) films of different chemical composition and number of monomolecular layers deposited on silylated silica glass substrates were studied by means of positron annihilation spectroscopy. The applied methods included the measurement of the Doppler broadening of the annihilation photopeak with variable energy positron beams and bulk positron lifetime measurements. The studied samples were 58 monomolecular layers (MML) thick Mg- and Cd-arachidate, arachidic acid (50 MML) and a series of Pb-arachidate samples with 4, 10, 20, 40, and 58 MML. The investigation showed that the variable energy positron beam technique is capable of measuring the thickness of the deposited LB films. The measured positron annihilation parameters are sensitive to the chemical composition of the films and the behavior of the films in a vacuum. The results confirmed the stability of salt base LB films in high vacuum conditions and showed the desorption of pure acid films. These investigations have also shown that a strong position trap is formed in the near-surface region of the hydrophobized substrate as a consequence of the silylation process. The results suggest that positron beams provide valuable complementary information to results obtained by other techniques.

  2. Measurement of the Energy Spectrum of Secondary Electrons Ejected from Solids by Positron Impact

    NASA Astrophysics Data System (ADS)

    Overton, N.; Coleman, P. G.

    1997-07-01

    Energy distributions of fast secondary electrons ejected from Cu and Si bombarded by positrons of energies in the range 50 to 2000 eV, incident at glancing angles \\(<=5°\\) and at 35°, have been fit to the form AE-m proposed by E. N. Sickafus. The absence of electron backscattering and the reduction of cascade effects common in electron-stimulated secondary electron spectra allow the direct determination of m for comparison with theory. The values obtained rise from 1.5 at 2000 eV to about 2.5 at 50 eV, and are all higher than those found for electrons incident at higher energies (0.5-1.5). No significant dependence of the value of m on target species or angle of incidence was observed.

  3. Method and apparatus for measuring minority carrier lifetime in a direct band-gap semiconductor

    NASA Technical Reports Server (NTRS)

    Vonroos, Oldwig (inventor)

    1987-01-01

    A direct band-gap semiconductor is exposed to intensity-modulated photon radiation having a characteristic energy at least as great as the energy gap of the semiconductor. This produces a time dependent concentration of excess charge carriers through the material, producing a luminescence signal modulated at the same frequency as the incident radiation but shifted in phase by an amount related to the lifetime of minority carriers. In a preferred embodiment, the phase shift of the luminescence signal is determined by transforming it to a modulated electrical signal and mixing the electrical signal with a reference signal modulated at the same frequency and having a phase which is known relative to the incident radiation. Minority carrier lifetime is calculated by integrating a direct current component of the mixed signal (F sub dc) over a 2 pi range in phase of the reference signal.

  4. Mathematical analysis of the Photovoltage Decay (PVD) method for minority carrier lifetime measurements

    NASA Technical Reports Server (NTRS)

    Vonroos, O. H.

    1982-01-01

    When the diffusion length of minority carriers becomes comparable with or larger than the thickness of a p-n junction solar cell, the characteristic decay of the photon-generated voltage results from a mixture of contributions with different time constants. The minority carrier recombination lifetime tau and the time constant l(2)/D, where l is essentially the thickness of the cell and D the minority carrier diffusion length, determine the signal as a function of time. It is shown that for ordinary solar cells (n(+)-p junctions), particularly when the diffusion length L of the minority carriers is larger than the cell thickness l, the excess carrier density decays according to exp (-t/tau-pi(2)Dt/4l(2)), tau being the lifetime. Therefore, tau can be readily determined by the photovoltage decay method once D and L are known.

  5. Lifetime measurements for the proposed antimagnetic rotational band in 101Pd

    NASA Astrophysics Data System (ADS)

    Sugawara, Masahiko; Hayakawa, Takehito; Oshima, Masumi; Toh, Yosuke; Osa, Akihiko; Matsuda, Makoto; Shizuma, Toshiyuki; Hatsukawa, Yuich; Kusakari, Hideshige; Morikawa, Tsuneyasu; Gan, Zaiguo; Czosnyka, Tomasz

    2014-09-01

    It has become well known by active researches in the last two decades that particle-hole combinations of dissimilar nucleons in high- j orbitals can create novel structures such as magnetic rotation (MR) bands and antimagnetic rotation (AMR) bands around doubly magic nuclei. We proposed an antimagnetic rotational band including the h11 / 2 neutron orbital in 101Pd based on the previous in-beam ?-ray spectroscopy by using the reaction 68Zn(37Cl,1p3n). However, we could not confirm the antimagnetic rotational character at that time for lack of lifetime data. Since a thick target was used in that experiment, it was possible to extract lifetimes for several levels in the ?h11 / 2 band through the analysis of Doppler broadened line shapes of ?-rays. The results of those analyses will be presented in this talk.

  6. Real-time readout and lifetime measurements of single-triplet states in a Si/SiGe double quantum dot

    NASA Astrophysics Data System (ADS)

    Prance, Jonathan; Shi, Zhan; Simmons, Christie; Savage, Don; Lagally, Max; Schreiber, Lars; Vandersypen, Lieven; Friesen, Mark; Joynt, Robert; Coppersmith, Sue; Eriksson, Mark

    2012-02-01

    The singlet and triplet states of a two-electron double quantum dot can be used as the basis for a logical qubit that combines fast gating and robust readout via Pauli spin blockade. We present measurements of the lifetimes of these states in a Si/SiGe double dot at magnetic fields between 1T and 0T [1]. The lifetimes are found by analyzing the statistics of repeated single-shot measurements of the spin state of the system. This technique allows multiple relaxation processes to be observed simultaneously. At zero magnetic field we find that all four spin states have lifetimes of approximately 10ms. With increasing magnetic field the lifetimes of the S and T0 states show no noticeable change, while the lifetime of the T- state rises, reaching 3 seconds at 1T. [1] J. R. Prance, et al., e-print: arxiv.org/abs/1110.6431

  7. High Statistics Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5–500 GeV with the Alpha Magnetic Spectrometer on the International Space Station

    E-print Network

    Becker, Ulrich J.

    A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy ...

  8. The ATLAS Positron Experiment -- APEX

    SciTech Connect

    Ahmad, I.; Back, B.B.; Betts, R.R.; Dunford, R.; Kutschera, W.; Rhein, M.D.; Schiffer, J.P.; Wilt, P.; Wuosmaa, A. [Argonne National Lab., IL (United States). Physics Div.; Austin, S.M.; Kashy, E.; Winfield, J.S.; Yurkon, J.E. [Michigan State Univ., East Lansing, MI (United States). NSCL; Bazin, D. [GANIL, Caen (France); Calaprice, F.P.; Young, A. [Princeton Univ., NJ (United States). Physics Dept.; Chan, K.C.; Chisti, A.; Chowhury, P.; Greenberg, J.S.; Kaloskamis, N.; Lister, C.J. [Yale Univ., New Haven, CT (United States). Wright Nuclear Structure Lab.; Fox, J.D.; Roa, E. [Florida State Univ., Tallahassee, FL (United States). Physics Dept.; Freedman, S.; Maier, M.R. [Lawrence Berkeley Lab., CA (United States); Freer, M. [Univ. of Birmingham (United Kingdom). Dept. of Physics; Gazes, S. [Univ. of Chicago, IL (United States). Dept. of Physics; Hallin, A.L.; Liu, M. [Queen`s Univ., Kingston, Ontario (Canada). Physics Dept.; Happ, T. [GSI, Darmstadt (Germany); Perera, A.; Wolfs, F.L.H. [Univ. of Rochester, NY (United States). NSRL; Trainor, T. [Univ. of Washington, Seattle, WA (United States). Nuclear Physics Lab.; Wolanski, M. [Argonne National Lab., IL (United States). Physics Div.]|[Univ. of Chicago, IL (United States). Dept. of Physics

    1994-03-01

    APEX -- the ATLAS Positron Experiment -- is designed to measure electrons and positrons emitted in heavy-ion collisions. Its scientific goal is to gain insight into the puzzling positron-line phenomena observed at the GSI Darmstadt. It is in operation at the ATLAS accelerator at Argonne National Lab. The assembly of the apparatus is finished and beginning 1993 the first positrons produced in heavy-ion collisions were observed. The first full scale experiment was carried out in December 1993, and the data are currently being analyzed. In this paper, the principles of operation are explained and a status report on the experiment is given.

  9. Lifetime of the 1s2s 3S1 metastable level in He-like S14+ measured with an electron beam ion trap

    SciTech Connect

    L?pez-Urrutia, J C; Beiersdorfer, P; Widmann, K

    2006-03-16

    A precision measurement of the lifetime of the lowest exited level of the He-like S{sup 14+} ion carried out at the Livermore EBIT-II electron beam ion trap yielded a value of (703 {+-} 4) ns. Our method extends the range of lifetime measurements accessible with electron beam ion traps into the nanosecond region and improves the accuracy of currently available data for this level by an order of magnitude.

  10. Decreased tumor blood flow as measured by positron emission tomography in cancer patients treated with interleukin-1 and carboplatin on a phase I trial

    Microsoft Academic Search

    Theodore F. Logan; Fayega Jadali; Merrill J. Egorin; Mark Mintun; Donald Sashin; William E. Gooding; Yong Choi; Harry Bishop; Donald L. Trump; Diane Gardner; John Kirkwood; Daniel Vlock; Candace Johnson

    2002-01-01

    Background. Positron emission tomography (PET) scanning can be used to measure blood flow. When interleukin-1a (IL-1) is given in a murine model, it induces acute hemorrhagic necrosis, tumor vascular injury and decreased tumor blood flow, and when given prior to carboplatin, there is enhanced antitumor activity compared to either agent alone. Methods. In a phase I trial of IL-1 and

  11. A Measurement of the Lifetime of the Lambda_b Baryon with the CDF Detector at the Tevatron Run II

    SciTech Connect

    Unverhau, Tatjana Alberta Hanna; /Glasgow U.

    2004-12-01

    In March 2001 the Tevatron accelerator entered its Run II phase, providing colliding proton and anti-proton beams with an unprecedented center-of-mass energy of 1.96 TeV. The Tevatron is currently the only accelerator to produce {Lambda}{sub b} baryons, which provides a unique opportunity to measure the properties of these particles. This thesis presents a measurement of the mean lifetime of the {Lambda}{sub b} baryon in the semileptonic channel {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +} {mu}{sup -} {bar {nu}}{sub {mu}}. In total 186 pb{sup -1} of data were used for this analysis, collected with the CDF detector between February 2002 and September 2003. To select the long-lived events from b-decays, the secondary vertex trigger was utilized. This significant addition to the trigger for Run II allows, for the first time, the selection of events with tracks displaced from the primary interaction vertex at the second trigger level. After the application of selection cuts this trigger sample contains approximately 991 {Lambda}{sub b} candidates. To extract the mean lifetime of {Lambda}{sub b} baryons from this sample, they transverse decay length of the candidates is fitted with an unbinned maximum likelihood fit under the consideration of the missing neutrino momentum and the bias introduced by the secondary vertex trigger. The mean lifetime of the {Lambda}{sub b} is measured to be {tau} = 1.29 {+-} 0.11(stat.) {+-} 0.07(syst.) ps equivalent to a mean decay length of c{tau} = 387 {+-} 33(stat.) {+-} 21 (syst.) {micro}m.

  12. Mass and lifetime measurements of bottom and charm baryons in pp ¯ collisions at ?s =1.96 TeV

    NASA Astrophysics Data System (ADS)

    Aaltonen, T.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; D'Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; Donati, S.; D'Onofrio, M.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Galloni, C.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. H.; Kim, S. B.; Kim, Y. J.; Kim, Y. K.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lucà, A.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Marchese, L.; Margaroli, F.; Marino, P.; Martínez, M.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Ranjan, N.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Song, H.; Sorin, V.; St. Denis, R.; Stancari, M.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Velev, G.; Vellidis, C.

    2014-04-01

    We report on mass and lifetime measurements of several ground state charmed and bottom baryons, using a data sample corresponding to 9.6 fb-1 from pp ¯ collisions at ?s =1.96 TeV and recorded with the Collider Detector at Fermilab. Baryon candidates are reconstructed from data collected with an online event selection designed for the collection of long-lifetime heavy-flavor decay products and a second event selection designed to collect J/?? ?+?- candidates. First evidence for the process ?b-??c0?- is presented with a significance of 3.3?. We measure the following baryon masses: M(?c0) =2470.85±0.24(stat)±0.55(syst) MeV/c2,M(?c+)=2468.00±0.18(stat)±0.51(syst) MeV/c2,M(?b)=5620.15±0.31(stat)±0.47(syst) MeV/c2,M(?b-)=5793.4±1.8(stat)±0.7(syst) MeV/c2,M(?b0)=5788.7±4.3(stat)±1.4(syst) MeV/c2,andM(?b-)=6047.5±3.8(stat)±0.6(syst) MeV/c2. The isospin splitting of the ?b-,0 states is found to be M(?b-)-M(?b0)=4.7±4.7(stat)±0.7(syst) MeV /c2. The isospin splitting of the ?c0,+ states is found to be M(?c0)-M(?c+)=2.85±0.30(stat)±0.04(syst) MeV /c2. The following lifetime measurements are made: ?(?b)=1.565±0.035(stat)±0.020(syst) ps ,?(?b-)=1.32±0.14(stat)±0.02(syst) ps ,?(?b-)=1.66-0.40+0.53(stat)±0.02(syst) ps

  13. Measurement of the branching fractions and lifetime of the $5D_{5/2}$ level of Ba$^+$

    E-print Network

    Auchter, Carolyn; Hoffman, Matthew R; Williams, Spencer R; Blinov, Boris B

    2014-01-01

    We present a measurement of the branching fractions for decay from the long-lived $5D_{5/2}$ level in Ba$^+$. The branching fraction for decay into the $6S_{1/2}$ ground state was found to be $0.846(25)_{stat}(4)_{sys}$. We also report an improved measurement of the $5D_{5/2}$ lifetime, $\\tau_{5D_{5/2}}=31.2(0.9)$ s. Together these measurements provide the first experimental determination of transition rates for decay out of the $5D_{5/2}$ level. The low ($<6.5 \\times 10^{-12}$ Torr) pressure in the ion trap in which these measurements were made simplified data acquisition and analysis. Comparison of the experimental results with theoretical predictions of the transition rates shows good agreement.

  14. Fluorescence lifetime, precision calorimetry, and fluorescence energy transfer measurements in the study of normal and tumoral chromatin structure

    NASA Astrophysics Data System (ADS)

    Radu, Liliana; Preoteasa, Vasile; Radulescu, Irina; Radu, Serban

    1997-06-01

    Chromatin is a complex of deoxyribonucleic acid (DNA) with proteins, that exists in the nuclei of eukaryotic cells. Three methods have been used to study protein-DNA interactions in chromatin and to compare the chromatin from normal tissue with that from tumoral tissue: determination of the fluorescence lifetimes and measurement of the heats of reaction of complexation of the ligand ethidium bromide with chromatin, and evaluation of the fluorescence energy transfer between two ligands dansyl chloride and acridine orange when coupled with chromatin.

  15. Measurements of photocathode operational lifetime at beam currents up to 10-mA using an improved DC high voltage GaAs photogun

    SciTech Connect

    J. Grames; M. Poelker; P. Adderley; J. Brittian; J. Clark; J. Hansknecht; D. Machie; M.L. Stutzman; K. Surles-Law

    2007-06-01

    This work extends past research at Jefferson Lab aimed at better appreciating the mechanisms that limit photocathode operational lifetime at high current (> 1 mA). Specifically, the performance of an improved 100 kV DC high voltage load locked photogun will be described. Although difficult to measure directly, we believe the new gun has better vacuum conditions compared to the original gun, as indicated by enhanced photocathode lifetimes exceeding 2000 C using a 1.55 mm diameter drive laser spot at the photocathode. In addition, the dependence of the lifetime on the laser spot size at the photocathode was measured and a charge density lifetime exceeding 10^6 C/cm^2 was measured with a 0.32 mm laser spot diameter.

  16. Using the earth's geomagnetic field to measure ultra-heavy cosmic ray abundances and electron and positron fluxes with CALET

    NASA Astrophysics Data System (ADS)

    Rauch, B. F.; CALET Collaboration

    2013-02-01

    The CALorimetric Electron Telescope (CALET) is an imaging calorimeter under construction for launch to the ISS in 2014 designed to measure electron energy spectra from 1 GeV to 20 TeV, detect gamma-rays above 10 GeV, and measure the energy spectra of nuclei from protons through iron up to 1,000 TeV [1]. CALET consists of a charge detection module (CHD) with two segmented planes of 1 cm thick plastic scintillator, an imaging calorimeter (IMC) with a total of 3 radiation lengths (r.l.) of tungsten plates read out with 8 planes of interleaved scintillating fibers, and a total absorption calorimeter (TASC) with 27 r.l. of lead tungstate (PWO) logs [2]. CALET can make additional cosmic ray measurements by exploiting the geomagnetic field it will be exposed to in the 51.6° degree inclination orbit on the ISS. The rare nuclei heavier than nickel (Z=28) can be resolved using the CHD and top IMC layers without requiring particle energy determination in the TASC in field regions where the rigidity cutoffs are above minimum ionization in the scintillator, yielding a nearly 4 times increase in geometry factor [3,4]. CALET can also measure the distinct fluxes of cosmic ray positrons and electrons using the East-West effect of particles traveling in the earth's geomagnetic field over an energy band of ~ 3 - 20 GeV [5].

  17. Positron Physics

    NASA Technical Reports Server (NTRS)

    Drachman, Richard J.

    2003-01-01

    I will give a review of the history of low-energy positron physics, experimental and theoretical, concentrating on the type of work pioneered by John Humberston and the positronics group at University College. This subject became a legitimate subfield of atomic physics under the enthusiastic direction of the late Sir Harrie Massey, and it attracted a diverse following throughout the world. At first purely theoretical, the subject has now expanded to include high brightness beams of low-energy positrons, positronium beams, and, lately, experiments involving anti-hydrogen atoms. The theory requires a certain type of persistence in its practitioners, as well as an eagerness to try new mathematical and numerical techniques. I will conclude with a short summary of some of the most interesting recent advances.

  18. Application of slow positrons to coating degradation

    Microsoft Academic Search

    H. Cao; R. Zhang; H. M Chen; P. Mallon; C.-M Huang; Y. He; T. C Sandreczki; Y. C Jean; B. Nielsen; T. Friessnegg; R. Suzuki; T. Ohdaira

    2000-01-01

    Photodegradation of a polyurethane-based topcoat induced by accelerated UV irradiation is studied using Doppler broadened energy spectra (DBES) and positron annihilation lifetime (PAL) spectroscopies coupled with slow positron technique. Significant and similar variations of S-parameter and ortho-positronium intensity (I3) in coatings are observed as functions of depth and of exposure time. The decrease of S is interpreted as a result

  19. Positron spectroscopy for materials characterization

    SciTech Connect

    Schultz, P.J.; Snead, C.L. Jr.

    1988-01-01

    One of the more active areas of research on materials involves the observation and characterization of defects. The discovery of positron localization in vacancy-type defects in solids in the 1960's initiated a vast number of experimental and theoretical investigations which continue to this day. Traditional positron annihilation spectroscopic techniques, including lifetime studies, angular correlation, and Doppler broadening of annihilation radiation, are still being applied to new problems in the bulk properties of simple metals and their alloys. In addition new techniques based on tunable sources of monoenergetic positron beams have, in the last 5 years, expanded the horizons to studies of surfaces, thin films, and interfaces. In the present paper we briefly review these experimental techniques, illustrating with some of the important accomplishments of the field. 40 refs., 19 figs.

  20. Forward-bias capacitance and current measurements for determining lifetimes and band narrowing in p-n junction solar cells

    NASA Technical Reports Server (NTRS)

    Neugroschel, A.; Chen, P. J.; Pao, S. C.; Lindholm, F. A.

    1978-01-01

    A new method is described and illustrated for determining the minority-carrier diffusion length and lifetime in the base region of p-n junction solar cells. The method requires only capacitance measurements at the device terminals and its accuracy is estimated to be + or - 5%. It is applied to a set of silicon p-n junction devices and the values of the diffusion lengths agree with those obtained using the current response to X-ray excitation but disagree with those obtained by the OCVD method. The reasons for the relative inaccuracy of OCVD applied to silicon devices are discussed. The capacitance method includes corrections for a two-dimensional fringing effects which occur in small area devices. For a device having highly-doped base region and surface (emitter) layer, the method can be extended to enable the determination of material properties of the degenerately doped surface layer. These material properties include the phenomenological emitter lifetime and a measure of the energy band-gap narrowing in the emitter. An alternate method for determining the energy band-gap narrowing from temperature dependence of emitter current is discussed and demonstrated.

  1. An investigation of molecular structure of copolymers using positron annihilation spectroscopy

    NASA Technical Reports Server (NTRS)

    Singh, J. J.; St.clair, T. L.; Holt, W. H.; Mock, W., Jr.

    1985-01-01

    Positron lifetime measurements were made in copolyimides synthesized from linear 4,4 prime-bis(3,4-dicarboxyphenoxy) diphenylsulfide dianhydride (BDSDA)/4,4 prime-diaminodiphenyl (ODA) and BDSDA/1,3-diaminobenzene (m-phenylene diamine) homopolymers. The probability of positronium formation as well as its subsequent lifetime are lower in the BDSDA/ODA/MPD (50-50) copolyimide, indicating the presence of a transition molecular architecture characterized by higher electron density and stronger bonds which permit both chemical as well as physical entry of water molecules into it. The presence of this transition region imparts unique physical and mechanical properties to the copolyimide.

  2. First Result from the Alpha Magnetic Spectrometer on the International Space Station: Precision Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5–350 GeV

    E-print Network

    Basil, A.

    A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8×10[superscript 6] positron ...

  3. Lifetime measurement of the 6.79 MeV state in {sup 15}O with the AGATA demonstrator

    SciTech Connect

    Depalo, R.; Michelagnoli, C.; Menegazzo, R.; Ur, C. A.; Bazzacco, D.; Bemmerer, D.; Broggini, C.; Caciolli, A.; Erhard, M.; Farnea, E.; Fueloep, Zs.; Gottardo, A.; Keeley, N.; Lunardi, S.; Marta, M.; Mengoni, D.; Mijatovic, T.; Recchia, F.; Rossi-Alvarez, C.; Szuecs, T. [INFN Sezione di Padova, Padova (Italy) and Dipartimento di Fisica dell'Universita di Padova, Padova (Italy); INFN Sezione di Padova, Padova (Italy); and others

    2012-11-20

    The {sup 14}N(p,{gamma}){sup 15}O reaction is the slowest process of the CN cycle, and thus it is of high astrophysical interest since it regulates the total rate of energy and neutrinos production through the cycle. The {sup 14}N+p ground state capture is strongly influenced by a sub-threshold resonance corresponding to the 6.79 MeV state in {sup 15}O. The width of this resonance is a major source of uncertainty in the extrapolation of the reaction cross section in the Gamow energy window. Preliminary results of a new Doppler Shift Attenuation measurement of the lifetime of the 6.79 MeV state in {sup 15}O are discussed. The level of interest was populated via the {sup 2}H({sup 14}N,n){sup 15}O reaction in inverse kinematics at 32 MeV beam energy. The gamma-rays emitted in the decay of the 6.79 MeV level to the ground state were detected with the AGATA Demonstrator array of high-purity germanium detectors. The sensitivity of the shape of the peak in the gamma-ray energy spectrum to the level lifetime is investigated comparing the experimental peaks with detailed Monte Carlo simulations of the reaction mechanisms and the gamma-ray emission and detection. Nuclear levels in {sup 15}N (also populated in the {sup 14}N+{sup 2}H reaction) for which the lifetimes are known in the literature provided a test of the analysis technique.

  4. Fluorescence intensity and lifetime measurement of free and particle-bound fluorophore in a sample stream by phase-sensitive flow cytometry

    SciTech Connect

    Steinkamp, John A. [Life Sciences Division, Cytometry Group LS-5, Mail Stop M888, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Life Sciences Division, Cytometry Group LS-5, Mail Stop M888, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Keij, Jan F. [Life Sciences Division, Cytometry Group LS-5, Mail Stop M888, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Life Sciences Division, Cytometry Group LS-5, Mail Stop M888, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    1999-12-01

    We report a novel method to quantify fluorescence intensity and lifetime of free (solution) and particle-bound fluorophore in a flow stream. The technique combines flow cytometry and frequency-domain lifetime spectroscopy principles to make unique fluorescence measurements on free fluorophore and fluorophore-labeled particles. Fluorophore-labeled microspheres suspended in a fluorophore solution are analyzed as they flow through a chamber and pass across an intensity-modulated laser beam consisting of a continuous-wave (cw) direct-current (dc) and high-frequency (sine wave) excitation component. Fluorescence emission signals consisting of a dc-offset steady-state sinusoidal signal (fluorophore solution) and a sinusoidally modulated Gaussian-shaped signal pulse (fluorophore-labeled particles) are processed electronically to quantify intensities and lifetimes. The cw-excited, particle-associated fluorophore (pulse) and steady-state (dc) solution fluorescence intensity signals are measured using low-pass filtering to remove the high-frequency signal components and an ac-coupled and a gated dc amplifier to process the respective particle-bound and free fluorophore signals. The high-frequency excited, particle-bound fluorophore and free fluorophore lifetimes are individually measured using two pairs of phase-sensitive detectors to provide signals proportional to the sine and cosine of the respective phase shifts, which are ratioed to determine the respective lifetimes. The fluorescence signal intensity and lifetime detection channel outputs are displayed as frequency distribution histograms using a computer-based data acquisition system. (c)

  5. Excess carrier lifetime of 3C{endash}SiC measured by the microwave photoconductivity decay method

    SciTech Connect

    Ichimura, M. [Center for Cooperative Research, Nagoya Institute of Technology, Gokiso, Nagoya 466 (Japan)] [Center for Cooperative Research, Nagoya Institute of Technology, Gokiso, Nagoya 466 (Japan); Tajiri, H.; Morita, Y.; Yamada, N.; Usami, A. [Department of Electrical and Computer Engineering, Nagoya Institute of Technology, Gokiso, Nagoya 466 (Japan)] [Department of Electrical and Computer Engineering, Nagoya Institute of Technology, Gokiso, Nagoya 466 (Japan)

    1997-03-01

    Excess carrier lifetime of 3C{endash}SiC grown on a Si substrate by chemical vapor deposition is measured at room temperature by the noncontact microwave photoconductivity decay method. A N{sub 2} laser is used to excite carriers in the SiC layer. The measured decay curves of the excess carrier concentration have fast ({tau}{approx}3 {mu}s) and slow ({tau}{gt}200 {mu}s) components. The origin of the slow decay is discussed on the basis of the numerical simulation of the recombination process, and the presence of traps with a very small electron capture cross section ({lt}1{times}10{sup {minus}21}cm{sup 2}) is predicted. {copyright} {ital 1997 American Institute of Physics.}

  6. Measurement of the B+-_c Meson Lifetime Using B+-_c -> J/psi + l+- + X Decays

    SciTech Connect

    Hartz, Mark Patrick; /Pittsburgh U.

    2008-11-01

    This thesis describes a measurement of the average proper decay time of the B{sub c}{sup {+-}} mesons, the ground state of bottom and charm quark bound states. The lifetime measurement is carried out in the decay modes B{sub c}{sup {+-}} {yields} J/{psi} + e{sup {+-}} + X and B{sub c}{sup {+-}} {yields} J/{psi} + {mu}{sup {+-}} + X, where the J/{psi} decays as J/{psi} {yields} {mu}{sup +}{mu}{sup -} and the X are unmeasured particles such as {nu}{sub e} or {nu}{sub {mu}}. The data are collect by the CDF II detector which measures the properties of particles created in {radical}s = 1.96 TeV p{bar p} collisions delivered by the Fermilab Tevatron. This measurement uses {approx} 1 fb{sup -1} of integrated luminosity. The measured average proper decay time of B{sub c}{sup {+-}} mesons, {tau} = 0.475{sub -0.049}{sup +0.053}(stat.) {+-} 0.018(syst.) ps, is competitive with the most precise measurements in the world and confirms previous measurements and theoretical predictions.

  7. Monitoring of labeled antisense oligonucleotides within living cells by using a multifrequency phase/modulation approach for fluorescence lifetime measurements

    NASA Astrophysics Data System (ADS)

    Kocisova, E.; Sureau, F.; Praus, P.; Rosenberg, I.; Stepanek, J.; Turpin, P.-Y.

    2003-06-01

    A multifrequency phase/modulation method has been developed for our UV confocal laser microspectrofluorimeter (modulation frequency 1-200 MHz) for fluorescence lifetime measurements. This technique enables excited state lifetimes of mixed fluorescent components to be resolved and the fluorescence spectral contribution of each species to be determined without using any model spectra. This approach is very efficient for analyzing intracellular multicomponent fluorescence signals. Our effort is focused on the elucidation of the intracellular behavior of synthetic modified oligonucleotides - potential drugs for antisense and/or antigene strategies of curing viral and malignant diseases. A novel type single stranded dT 15 oligomer analogue containing isopolar, non-isosteric, phosphonate-based internucleotide linkages (3'-O-P-CH 2-O-5'), labeled with tetramethylrhodamine dye at the 3'-end, has been utilized. This method, along with fluorescence micro-imaging, was used to monitor uptake, distribution and stability of our modified oligonucleotide inside living cells. Binding to Escort™ vector leads to an homogeneous intracellular distribution of fluorescent labeled oligonucleotide, including nucleus staining, while point distribution only is achieved for its free form.

  8. Steady-state and frequency-domain lifetime measurements of an activated molecular imprinted polymer imprinted to dipicolinic acid.

    PubMed

    Anderson, John; Nelson, Jean; Reynolds, Charles; Ringelberg, Dave; Tepper, Gary; Pestov, Dmitry

    2004-05-01

    We recently demonstrated the synthesis and fluorescence activity associated with an optical detector incorporating a molecular imprinted polymer (MIP). Steady-state and time-resolved (lifetime) fluorescence measurements were used to characterize the binding activity associated with MIP microparticles imprinted to dipicolinic acid (DPA). DPA is a unique biomarker associated with the sporulation phase of endospore-forming bacteria. Vinylic monomers were polymerized in a dimethylformamide solution containing DPA as a template. The resulting MIP was then pulverized and sorted into small microscale particles. Tests were conducted on replicate samples of biologically active cultures representing both vegetative stationary phase and sporulation phase of Bacillus subtilis in standard media. Samplers were adapted incorporating the MIP particles within a dialyzer cartridge (500 MW). The permeability of the dialyzer membrane permitted diffusion of lighter molecular weight constituents from microbial media effluents to enter the dialyzer chamber and come in contact with the MIP. Results showed dramatic (10-fold over background) steady-state fluorescence changes (as a function of excitation, emission and intensity) for samples associated with high endospore biomass (DPA), and a frequency-domain lifetime of 5.3 ns for the MIP-DPA complex. PMID:15615208

  9. Polarized Electrons for Polarized Positrons

    NASA Astrophysics Data System (ADS)

    Fanchini, Erica

    2012-03-01

    Recently, the nuclear and high-energy physics communities have shown a growing interest in the availability of high current, highly spin-polarized positron beams. The Polarized Electrons for Polarized Positrons (PEPPo) experiment at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) aims to measure the transfer of polarization from a low energy 10 MeV highly spin polarized electron beam to positrons. A sufficiently energetic polarized photon or lepton may generate, via bremsstrahlung and pair creation processes within a target foil, electron-positron pairs that will carry a fraction of the initial polarization. This approach has been successfully tested using polarized photons created with a multi-GeV unpolarized electron beam, resulting in positrons with polarization of 80%. Although pair creation yield is reduced at lower energy, recent advances in high current milliampere spin-polarized electron sources at Jefferson Lab offer the perspective of creating polarized positrons using a low energy electron beam. A successful demonstration of this technique would provide an alternative scheme to produce low energy polarized positrons, as well as useful information to optimize the design of a polarized positron source using sub-GeV electron beam. An overview and status of the PEPPo experiment will be presented, along with some of the motivations in the context of the Jefferson Lab nuclear physics program.

  10. Positron annihilation studies of Eu and Dy doped ?'-Sr2SiO4

    NASA Astrophysics Data System (ADS)

    Gupta, S. K.; Sudarshan, K.; Sharma, S. K.; Pujari, P. K.; Natarajan, V.

    2015-06-01

    Sr2SiO4 is an important inorganic host for lanthanide doped white light emitting diodes (LEDs). Strontium silicate (Sr2SiO4) samples doped with 1.0 mol% of Eu3+ and Dy3+ content were prepared via sol-gel route and characterized by X-ray diffraction (XRD), Raman spectroscopy and positron annihilation spectroscopy (PAS). The concentration of the dopant ion and the temperature of annealing were optimized for maximum luminescence intensity. The positron annihilation lifetime and coincidence Doppler broadening (CDB) measurements indicated that the local environment around the positron annihilation site is different in Eu+3 doped and Dy+3 doped samples. The results could be explained based on the different local site occupancy of Eu+3 and Dy+3 in the matrix.

  11. Slow-Positron Generator For Studying Polymer Films

    NASA Technical Reports Server (NTRS)

    Singh, Jag J.; St. Clair, Terry L.; Eftekhari, Abe

    1992-01-01

    Aspects of molecular structures probed by positron-annihilation spectroscopy (PAS). Slow-positron-beam generator suitable for PAS measurements in thin polymer films. Includes Na22 source of positrons and two moderators made of well-annealed tungsten foil. With proper choice of voltage, positrons emitted by inward-facing surfaces of moderators made to stop in polymer films tested.

  12. PET imaging of thin objects: measuring the effects of positron range and partial-volume averaging in the leag of Nicotiana Tabacum

    SciTech Connect

    Alexoff, D.L.; Alexoff, D.L.; Dewey, S.L.; Vaska, P.; Krishnamoorthy, S.; Ferrieri, R.; Schueller, M.; Schlyer, D.; Fowler, J.S.

    2011-03-01

    PET imaging in plants is receiving increased interest as a new strategy to measure plant responses to environmental stimuli and as a tool for phenotyping genetically engineered plants. PET imaging in plants, however, poses new challenges. In particular, the leaves of most plants are so thin that a large fraction of positrons emitted from PET isotopes ({sup 18}F, {sup 11}C, {sup 13}N) escape while even state-of-the-art PET cameras have significant partial-volume errors for such thin objects. Although these limitations are acknowledged by researchers, little data have been published on them. Here we measured the magnitude and distribution of escaping positrons from the leaf of Nicotiana tabacum for the radionuclides {sup 18}F, {sup 11}C and {sup 13}N using a commercial small-animal PET scanner. Imaging results were compared to radionuclide concentrations measured from dissection and counting and to a Monte Carlo simulation using GATE (Geant4 Application for Tomographic Emission). Simulated and experimentally determined escape fractions were consistent. The fractions of positrons (mean {+-} S.D.) escaping the leaf parenchyma were measured to be 59 {+-} 1.1%, 64 {+-} 4.4% and 67 {+-} 1.9% for {sup 18}F, {sup 11}C and {sup 13}N, respectively. Escape fractions were lower in thicker leaf areas like the midrib. Partial-volume averaging underestimated activity concentrations in the leaf blade by a factor of 10 to 15. The foregoing effects combine to yield PET images whose contrast does not reflect the actual activity concentrations. These errors can be largely corrected by integrating activity along the PET axis perpendicular to the leaf surface, including detection of escaped positrons, and calculating concentration using a measured leaf thickness.

  13. Effects of central cholinergic blockade on striatal dopamine release measured with positron emission tomography in normal human subjects.

    PubMed Central

    Dewey, S L; Smith, G S; Logan, J; Brodie, J D; Simkowitz, P; MacGregor, R R; Fowler, J S; Volkow, N D; Wolf, A P

    1993-01-01

    Previously we demonstrated that positron emission tomography (PET) can be used to measure changes in the concentrations of synaptic dopamine and acetylcholine. Whether induced directly or indirectly through interactions with other neurotransmitters, these studies support the use of PET for investigating the functional responsiveness of a specific neurotransmitter to a pharmacologic challenge. In an extension of these findings to the human brain, PET studies designed to measure the responsiveness of striatal dopamine release to central cholinergic blockade were conducted in normal male volunteers using high-resolution PET and [11C]raclopride, a D2-dopamine receptor antagonist. [11C]Raclopride scans were performed prior to and 30 min after systemic administration of the potent muscarinic cholinergic antagonist, scopolamine (0.007 mg/kg). After scopolamine administration, [11C]raclopride binding decreased in the striatum (specific binding) but not in the cerebellum (nonspecific binding) resulting in a significant decrease, exceeding the test/retest variability of this ligand (5%), in the ratio of the distribution volumes of the striatum to the cerebellum (17%). Furthermore, scopolamine administration did not alter the systemic rate of [11C]raclopride metabolism or the metabolite-corrected plasma input function. These results are consistent not only with the known inhibitory influence that acetylcholine exerts on striatal dopamine release but also with our initial 18F-labeled N-methylspiroperidol and benztropine studies. Thus these data support the use of PET for measuring the functional responsiveness of an endogenous neurotransmitter to an indirect pharmacologic challenge in the living human brain. Images Fig. 2 PMID:8265632

  14. Optical fiber-based setup for in vivo measurement of the delayed fluorescence lifetime of oxygen sensors

    NASA Astrophysics Data System (ADS)

    Piffaretti, Filippo M.; Santhakumar, Kanappan; Forte, Eddy; van den Bergh, Hubert E.; Wagnières, Georges A.

    2011-03-01

    A new optical-fiber-based spectrofluorometer for in vivo or in vitro detection of delayed fluorescence is presented and characterized. This compact setup is designed so that it can be readily adapted for future clinical use. Optical excitation is done with a nitrogen laser-pumped, tunable dye laser, emitting in the UV-vis part of the spectrum. Excitation and luminescence signals are carried to and from the biological tissues under investigation, located out of the setup enclosure, by a single optical fiber. These measurements, as well as measurements performed without a fiber on in vitro samples in a thermostable quartz cell, in a controlled-atmosphere enclosure, are possible due to the efficient collection of the laser-induced luminescence light which is collected and focused on the detector with a high aperture parabolic mirror. The detection is based on a gated photomultiplier which allows for time-resolved measurements of the delayed fluorescence intensity. Thus, relevant luminescence lifetimes, typically in the sub-microsecond-to-millisecond range, can be measured with near total rejection of the sample's prompt fluorescence. The instrument spectral and temporal resolution, as well as its sensitivity, is characterized and measurement examples are presented. The primary application foreseen for this setup is the monitoring and adjustment of the light dose delivered during photodynamic therapy.

  15. A measurement of the lifetime and mixing frequency of neutral B mesons with semileptonic decays in the BABAR detector

    NASA Astrophysics Data System (ADS)

    Cheng, Chih-Hsiang

    The neutral B meson, consisting of a b quark and an anti-d quark, can mix (oscillate) to its own anti-particle through second-order weak interactions. The measurement of the mixing frequency can constrain the quark mixing matrix in the Standard Model of particle physics. The PEP-II B-factory at the Stanford Linear Accelerator Center provides a very large data sample that enables us to make measurements with much higher precisions than previous measurements, and to probe physics beyond the Standard Model. The lifetime of the neutral B meson tB0 and the B0-B¯ 0 mixing frequency Deltamd are measured with a sample of approximately 14,000 exclusively reconstructed B 0 ? D*-? +nu? signal events, selected from 23 million BB¯ pairs recorded at the Upsilon(4S) resonance with the BABAR detector at the asymmetric-energy e +e- collider, PEP-II. The decay position of the other B is determined inclusively, and its b-quark flavor at the time of decay is determined (tagged) with the charge of tracks in the final state, where identified leptons or kaons give the most information. The decay time difference of two B mesons in the event is calculated from the distance between their decay vertices and the Lorentz boost of the center of mass. The lifetime and mixing frequency, along with wrong-tag probabilities and the time-difference resolution function, are measured simultaneously with an unbinned maximum-likelihood fit that uses, for each event, the measured difference in B decay times (Deltat), the calculated uncertainty on Deltat, the signal and background probabilities, and b-quark tagging for the other B meson. The results are tB0=1.523 +0.024-0.023+/-0.022 ps Dmd=0.492+/-0.018+/- 0.013ps-1, where the first error is statistical and the second is systematic. The statistical correlation coefficient between tB0 and Deltamd is -0.22. This result is consistent with the current world average values, the total errors are comparable with other most-precise measurements.

  16. Probing Positron Gravitation at HERA

    E-print Network

    Gharibyan, Vahagn

    2015-01-01

    An equality of particle and antiparticle gravitational interactions holds in general relativity and is supported by indirect observations. Here I develop a method based on high energy Compton scattering to measure the gravitational interaction of accelerated charged particles. Within that formalism the Compton spectra measured at HERA rule out the positron's anti-gravity and hint for a positron's 1.3(0.2)\\% weaker coupling to the gravitational field relative to an electron.

  17. Probing Positron Gravitation at HERA

    E-print Network

    Vahagn Gharibyan

    2015-07-06

    An equality of particle and antiparticle gravitational interactions holds in general relativity and is supported by indirect observations. Here I develop a method based on high energy Compton scattering to measure the gravitational interaction of accelerated charged particles. Within that formalism the Compton spectra measured at HERA rule out the positron's anti-gravity and hint for a positron's 1.3(0.2)\\% weaker coupling to the gravitational field relative to an electron.

  18. Measurement of the azimuthal correlation between the most forward jet and the scattered positron in deep-inelastic scattering at HERA

    NASA Astrophysics Data System (ADS)

    Aaron, F. D.; Alexa, C.; Andreev, V.; Backovic, S.; Baghdasaryan, A.; Baghdasaryan, S.; Barrelet, E.; Bartel, W.; Begzsuren, K.; Belousov, A.; Belov, P.; Bizot, J. C.; Boudry, V.; Bozovic-Jelisavcic, I.; Bracinik, J.; Brandt, G.; Brinkmann, M.; Brisson, V.; Britzger, D.; Bruncko, D.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A. J.; Cantun Avila, K. B.; Ceccopieri, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Contreras, J. G.; Coughlan, J. A.; Cvach, J.; Dainton, J. B.; Daum, K.; Delcourt, B.; Delvax, J.; De Wolf, E. A.; Diaconu, C.; Dobre, M.; Dodonov, V.; Dossanov, A.; Dubak, A.; Eckerlin, G.; Egli, S.; Eliseev, A.; Elsen, E.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Fischer, D.-J.; Fleischer, M.; Fomenko, A.; Gabathuler, E.; Gayler, J.; Ghazaryan, S.; Glazov, A.; Goerlich, L.; Gogitidze, N.; Gouzevitch, M.; Grab, C.; Grebenyuk, A.; Greenshaw, T.; Grell, B. R.; Grindhammer, G.; Habib, S.; Haidt, D.; Helebrant, C.; Henderson, R. C. W.; Hennekemper, E.; Henschel, H.; Herbst, M.; Herrera, G.; Hildebrandt, M.; Hiller, K. H.; Hoffmann, D.; Horisberger, R.; Hreus, T.; Huber, F.; Jacquet, M.; Janssen, X.; Jönsson, L.; Jung, H.; Kapichine, M.; Kenyon, I. R.; Kiesling, C.; Klein, M.; Kleinwort, C.; Kluge, T.; Kogler, R.; Kostka, P.; Kraemer, M.; Kretzschmar, J.; Krüger, K.; Landon, M. P. J.; Lange, W.; Laštovi?ka-Medin, G.; Laycock, P.; Lebedev, A.; Lendermann, V.; Levonian, S.; Lipka, K.; List, B.; List, J.; Lopez-Fernandez, R.; Lubimov, V.; Makankine, A.; Malinovski, E.; Marage, P.; Martyn, H.-U.; Maxfield, S. J.; Mehta, A.; Meyer, A. B.; Meyer, H.; Meyer, J.; Mikocki, S.; Milcewicz-Mika, I.; Moreau, F.; Morozov, A.; Morris, J. V.; Mudrinic, M.; Müller, K.; Naumann, Th.; Newman, P. R.; Niebuhr, C.; Nikitin, D.; Nowak, G.; Nowak, K.; Olsson, J. E.; Ozerov, D.; Pahl, P.; Palichik, V.; Panagoulias, I.; Pandurovic, M.; Papadopoulou, Th.; Pascaud, C.; Patel, G. D.; Perez, E.; Petrukhin, A.; Picuric, I.; Piec, S.; Pirumov, H.; Pitzl, D.; Pla?akyt?, R.; Pokorny, B.; Polifka, R.; Povh, B.; Radescu, V.; Raicevic, N.; Ravdandorj, T.; Reimer, P.; Rizvi, E.; Robmann, P.; Roosen, R.; Rostovtsev, A.; Rotaru, M.; Ruiz Tabasco, J. E.; Rusakov, S.; Šálek, D.; Sankey, D. P. C.; Sauter, M.; Sauvan, E.; Schmitt, S.; Schoeffel, L.; Schöning, A.; Schultz-Coulon, H.-C.; Sefkow, F.; Shtarkov, L. N.; Shushkevich, S.; Sloan, T.; Smiljanic, I.; Soloviev, Y.; Sopicki, P.; South, D.; Spaskov, V.; Specka, A.; Staykova, Z.; Steder, M.; Stella, B.; Stoicea, G.; Straumann, U.; Sykora, T.; Thompson, P. D.; Tran, T. H.; Traynor, D.; Truöl, P.; Tsakov, I.; Tseepeldorj, B.; Turnau, J.; Valkárová, A.; Vallée, C.; Van Mechelen, P.; Vazdik, Y.; Wegener, D.; Wünsch, E.; Žá?ek, J.; Zálešák, J.; Zhang, Z.; Zhokin, A.; Zohrabyan, H.; Zomer, F.

    2012-03-01

    Deep-inelastic positron-proton scattering events at low photon virtuality, Q 2, with a forward jet, produced at small angles with respect to the proton beam, are measured with the H1 detector at HERA. A subsample of events with an additional jet in the central region is also studied. For both samples, differential cross sections and normalised distributions are measured as a function of the azimuthal angle difference, ? ?, between the forward jet and the scattered positron in bins of the rapidity distance, Y, between them. The data are compared to predictions of Monte Carlo generators based on different evolution approaches as well as to next-to-leading order calculations in order to test the sensitivity to QCD evolution mechanisms.

  19. Measurement of the B?s lifetime in the flavor-specific decay channel B?s ? D?s ???X

    DOE PAGESBeta

    Abazov, V.? M. [Joint Inst. for Nuclear Research (JINR), Moscow (Russia); Abbott, B. [Univ. of Oklahoma, Norman, OK (United States); Acharya, B.? S. [Tata Inst. of Fundamental Research, Mumbai (India); Adams, M. [Univ. of Illinois, Chicago, IL (United States); Adams, T. [Florida State Univ., Tallahassee, FL (United States); Agnew, J.? P. [Univ. of Manchester (United Kingdom); Alexeev, G.? D. [Joint Inst. for Nuclear Research (JINR), Dubna (Russian Federation); Alkhazov, G. [Petersburg Nuclear Physics Inst., St. Petersburg (Russia); Alton, A. [Univ. of Michigan, Ann Arbor, MI (United States); Askew, A. [Florida State Univ., Tallahassee, FL (United States); Atkins, S. [Louisiana Tech Univ., Ruston, LA (United States); Augsten, K. [Czech Technical Univ., Prague (Czech Republic); Avila, C. [Univ. de los Andes, Bogota (Columbia); Badaud, F. [Univ. Blaise Pascal, Clermont (France); Bagby, L. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Baldin, B. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Bandurin, D.? V. [Univ. of Virginia, Charlottesville, VA (United States); Banerjee, S. [Tata Inst. of Fundamental Research, Mumbai (India); Barberis, E.; Baringer, P.; Bartlett, J.? F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S.? B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bhat, P.? C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E.? E.; Borissov, G.; Borysova, M.; Brandt, A.; Brandt, O.; Brock, R.; Bross, A.; Brown, D.; Bu, X.? B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C.? P.; Camacho-Pérez, E.; Casey, B.? C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chan, K.? M.; Chandra, A.; Chapon, E.; Chen, G.; Cho, S.? W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W.? E.; Corcoran, M.; Couderc, F.; Cousinou, M. -C.; Cutts, D.; Das, A.; Davies, G.; de Jong, S.? J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S.? P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H.? T.; Diesburg, M.; Ding, P.? F.; Dominguez, A.; Dubey, A.; Dudko, L.? V.; Duperrin, A.; Dutt, S.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V.? D.; Enari, Y.; Evans, H.; Evdokimov, V.? N.; Fauré, A.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H.? E.; Fortner, M.; Fox, H.; Fuess, S.; Garbincius, P.? H.; Garcia-Bellido, A.; García-González, J.? A.; Gavrilov, V.; Geng, W.; Gerber, C.? E.; Gershtein, Y.; Ginther, G.; Gogota, O.; Golovanov, G.; Grannis, P.? D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J. -F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M.? W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J.? M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A.? P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M.? D.; Hirosky, R.; Hoang, T.; Hobbs, J.? D.; Hoeneisen, B.; Hogan, J.; Hohlfeld, M.; Holzbauer, J.? L.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A.? S.; Jabeen, S.; Jaffré, M.; Jayasinghe, A.; Jeong, M.? S.; Jesik, R.; Jiang, P.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A.? W.; Juste, A.; Kajfasz, E.; Karmanov, D.; Katsanos, I.; Kaur, M.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y.? N.; Kiselevich, I.; Kohli, J.? M.; Kozelov, A.? V.; Kraus, J.; Kumar, A.; Kupco, A.; Kur?a, T.; Kuzmin, V.? A.; Lammers, S.; Lebrun, P.; Lee, H.? S.; Lee, S.? W.; Lee, W.? M.; Lei, X.; Lellouch, J.; Li, D.; Li, H.; Li, L.; Li, Q.? Z.; Lim, J.? K.; Lincoln, D.; Linnemann, J.; Lipaev, V.? V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Luna-Garcia, R.; Lyon, A.? L.; Maciel, A. K. A.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V.? L.; Mansour, J.; Martínez-Ortega, J.; McCarthy, R.; McGivern, C.? L.; Meijer, M.? M.; Melnitchouk, A.; Menezes, D.; Mercadante, P.? G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N.? K.; Mulhearn, M.; Nagy, E.; Narain, M.; Nayyar, R.; Neal, H.? A.; Negret, J.? P.; Neustroev, P.; Nguyen, H.? T.; Nunnemann, T.; Orduna, J.; Osman, N.; Osta, J.; Pal, A.; Parashar, N.; Parihar, V.; Park, S.? K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.

    2015-02-01

    We present an updated measurement of the B?s lifetime using the semileptonic decays B?s ? D?s ???X, with D?s ? ??? and ? ? K?K? (and the charge conjugate process). This measurement uses the full Tevatron Run II sample of proton-antiproton collisions at ?s = 1.96 TeV, comprising an integrated luminosity of 10.4 fb?1. We find a flavor-specifc lifetime Tfs(B?s) = 1.479 ± 0.010 (stat) ± 0.021 (syst) ps. This technique is also used to determine the B? lifetime using the analogous B? ? D????X decay with D? ? ??? and ? ? K?K? , yielding T(B?) = 1.534 ± 0.019 (stat) ± 0.021 (syst) ps. Both measurements are consistent with the current world averages, and the B?s lifetime measurement is one of the most precise to date. Taking advantage of the cancellation of systematic uncertainties, we determine the lifetime ratio Tfs(B?s)/T(B?) = 0.964 ± 0.013 (stat) ± 0.007 (syst).

  20. Measurement of the B?s lifetime in the flavor-specific decay channel B?s ? D?s ???X

    DOE PAGESBeta

    Abazov, V.? M.; Abbott, B.; Acharya, B.? S.; Adams, M.; Adams, T.; Agnew, J.? P.; Alexeev, G.? D.; Alkhazov, G.; Alton, A.; Askew, A.; et al

    2015-02-01

    We present an updated measurement of the B?s lifetime using the semileptonic decays B?s ? D?s ???X, with D?s ? ??? and ? ? K?K? (and the charge conjugate process). This measurement uses the full Tevatron Run II sample of proton-antiproton collisions at ?s = 1.96 TeV, comprising an integrated luminosity of 10.4 fb?1. We find a flavor-specifc lifetime Tfs(B?s) = 1.479 ± 0.010 (stat) ± 0.021 (syst) ps. This technique is also used to determine the B? lifetime using the analogous B? ? D????X decay with D? ? ??? and ? ? K?K? , yielding T(B?) = 1.534 ±more »0.019 (stat) ± 0.021 (syst) ps. Both measurements are consistent with the current world averages, and the B?s lifetime measurement is one of the most precise to date. Taking advantage of the cancellation of systematic uncertainties, we determine the lifetime ratio Tfs(B?s)/T(B?) = 0.964 ± 0.013 (stat) ± 0.007 (syst).« less

  1. The Neutron Lifetime

    E-print Network

    F. E. Wietfeldt

    2014-11-13

    The decay of the free neutron into a proton, electron, and antineutrino is the prototype semileptonic weak decay and the simplest example of nuclear beta decay. The nucleon vector and axial vector weak coupling constants G_V and G_A determine the neutron lifetime as well as the strengths of weak interaction processes involving free neutrons and protons that are important in astrophysics, cosmology, solar physics and neutrino detection. In combination with a neutron decay angular correlation measurement, the neutron lifetime can be used to determine the first element of the CKM matrix Vud. Unfortunately the two main experimental methods for measuring the neutron lifetime currently disagree by almost 4 sigma. I will present a brief review of the status of the neutron lifetime and prospects for the future.

  2. Substance Abuse Among High-Risk Sexual Offenders: Do Measures of Lifetime History of Substance Abuse Add to the Prediction of Recidivism Over Actuarial Risk Assessment Instruments?

    Microsoft Academic Search

    Jan Looman; Jeffrey Abracen

    2011-01-01

    There has been relatively little research on the degree to which measures of lifetime history of substance abuse add to the prediction of risk based on actuarial measures alone among sexual offenders. This issue is of relevance in that a history of substance abuse is related to relapse to substance using behavior. Furthermore, substance use has been found to be

  3. Substance Abuse among High-Risk Sexual Offenders: Do Measures of Lifetime History of Substance Abuse Add to the Prediction of Recidivism over Actuarial Risk Assessment Instruments?

    ERIC Educational Resources Information Center

    Looman, Jan; Abracen, Jeffrey

    2011-01-01

    There has been relatively little research on the degree to which measures of lifetime history of substance abuse add to the prediction of risk based on actuarial measures alone among sexual offenders. This issue is of relevance in that a history of substance abuse is related to relapse to substance using behavior. Furthermore, substance use has…

  4. Measurement of clinical and subclinical tumour response using [ 18F]-fluorodeoxyglucose and positron emission tomography: review and 1999 EORTC recommendations

    Microsoft Academic Search

    H. Young; R. Baum; U. Cremerius; K. Herholz; O. Hoekstra; A. A. Lammertsma; J. Pruim; P. Price

    1999-01-01

    [18F]-fluorodeoxyglucose ([18F]-FDG) uptake is enhanced in most malignant tumours which in turn can be measured using positron emission tomography (PET). A number of small clinical trials have indicated that quantification of the change in tumour [18F]-FDG uptake may provide an early, sensitive, pharmacodynamic marker of the tumoricidal effect of anticancer drugs. This may allow for the introduction of subclinical response

  5. Implantation profile of 22Na continuous energy spectrum positrons in silicon

    Microsoft Academic Search

    P. J. Foster; P. Mascher; A. P. Knights; P. G. Coleman

    2007-01-01

    The implantation profile of positrons emitted from a continuous energy spectrum source of 22Na in close proximity to a silicon target is modeled. The primary motivation is the use of positron lifetime spectroscopy to characterize layers of defects such as those created by ion irradiation, usually deemed accessible only to techniques which utilize slow positrons. The model combines the Makhov

  6. Lifetime measurements of triaxial strongly deformed bands in {sup 163}Tm.

    SciTech Connect

    Wang, X.; Janssens, R. V. F.; Moore, E. F.; Garg, U.; Gu, Y.; Frauendorf, S.; Carpenter, M. P.; Ghugre, S. S.; Hammond, N. J.; Lauritsen, T.; Li, T.; Mukherjee, G.; Pattabiraman, N. S.; Seweryniak, D.; Zhu, S.; Physics; Univ. of Notre Dame; Kolkata Center

    2007-06-21

    With the Doppler Shift Attenuation Method, quadrupole transition moments Qt were determined for the two recently proposed triaxial strongly deformed (TSD) bands in {sup 163}Tm. The measured Qt values indicate that the deformation of these bands is larger than that of the yrast signature partners. However, the measured values are smaller than those predicted by theory. This observation appears to be valid for TSD bands in several nuclei of the region.

  7. Polarized positron annihilation in ferromagnetic gadolinium

    Microsoft Academic Search

    C. Hohenemser; J. M. Weingart; S. Berko

    1968-01-01

    Measurements of the angular correlation of positron annihilation radiation in ferromagnetic Gd are presented, and observed polarization effects are attributed to anisotropic spin alignment of the conduction band.

  8. Measuring the branching ratio of the rare decay neutral pion going to electron-positron

    NASA Astrophysics Data System (ADS)

    Niclasen, Rune

    A precise branching ratio measurement of the rare decay pi0 ? e+e - has been made. The measurement was made with the rare kaon decay experiment KTeV at Fermilab where the source of pi0s was KL ? pi0pi 0pi0 decaying in flight. A total of 794 fully reconstructed KL ? 3pi0 events consistent with two of the intermediate pi0s decaying into gammagamma and one into e+e- were collected. An estimated 53.2 +/- 11.0 of these events were expected to be background. Normalizing to the pi0 Dalitz decay we found Br(p 0?e+e-, me+e-mp 02>0 .95)=6.44+/-0.25st at+/-0.22sys x10 -81 where internal radiation, pi0 ? e+e-(gamma), was limited by the requirement ( me+e- /mpi0)2 > 0.95 which separated it from the tree level Dalitz decay, pi0 ? e+e-gamma.

  9. Positron clouds within thunderstorms

    E-print Network

    Dwyer, Joseph R; Hazelton, Bryna J; Grefenstette, Brian W; Kelley, Nicole A; Lowell, Alexander W; Schaal, Meagan M; Rassoul, Hamid K

    2015-01-01

    We report the observation of two isolated clouds of positrons inside an active thunderstorm. These observations were made by the Airborne Detector for Energetic Lightning Emissions (ADELE), an array of six gamma-ray detectors, which flew on a Gulfstream V jet aircraft through the top of an active thunderstorm in August 2009. ADELE recorded two 511 keV gamma-ray count rate enhancements, 35 seconds apart, each lasting approximately 0.2 seconds. The enhancements, which were about a factor of 12 above background, were both accompanied by electrical activity as measured by a flat-plate antenna on the underside of the aircraft. The energy spectra were consistent with a source mostly composed of positron annihilation gamma rays, with a prominent 511 keV line clearly visible in the data. Model fits to the data suggest that the aircraft was briefly immersed in clouds of positrons, more than a kilometer across. It is not clear how the positron clouds were created within the thunderstorm, but it is possible they were ca...

  10. THz Measurement of Scattering Lifetime in CaRuO3 Films

    Microsoft Academic Search

    Saeid Kamal; J. Steven Dodge; Dong-Min Kim; Chang-Beom Eom

    2004-01-01

    We have studied the electrodynamics properties of CaRuO3 films using time domain THz spectroscopy techniques. The CaRuO3 films were grown on vicinal NdGaO3 substrates with 4 degree miscut which allows growth of high quality films with low residual resistivity. We have measured the complex conductivity as a function of temperature from 5 K to 300 K and as a function

  11. Comparison of energy distributions of positron- and electron-induced secondary electrons: Implications for slow positron emission mechanisms

    NASA Astrophysics Data System (ADS)

    Mayer, R.; Gramsch, E.; Weiss, A.

    1989-12-01

    Positron- and electron-induced secondary-electron-energy distributions have been measured from MgO(100) and Ni(110) crystals. The energy distributions for positron- and electron-induced secondary electrons from MgO and Ni and for the slow-positron emission from the MgO target have been fit by the same analytic function. This analytic function fails to fit the slow-positron energy emission spectrum from Ni. The similarity of positron-induced secondary electron and reemitted positron energy spectra suggests that the slow-positron emission process in ionic insulators may be analogous to secondary-electron generation.

  12. Comparison of energy distributions of positron- and electron-induced secondary electrons: Implications for slow positron emission mechanisms

    Microsoft Academic Search

    R. Mayer; E. Gramsch; A. Weiss

    1989-01-01

    Positron- and electron-induced secondary-electron-energy distributions have been measured from MgO(100) and Ni(110) crystals. The energy distributions for positron- and electron-induced secondary electrons from MgO and Ni and for the slow-positron emission from the MgO target have been fit by the same analytic function. This analytic function fails to fit the slow-positron energy emission spectrum from Ni. The similarity of positron-induced

  13. In-situ characterization of free-volume holes in polymer thin films under controlled humidity conditions with an atmospheric positron probe microanalyzer

    SciTech Connect

    Zhou Wei; Oshima, Nagayasu; O'Rourke, Brian E.; Kuroda, Ryunosuke; Suzuki, Ryoichi [Research Institute of Instrumentation Frontier (RIIF), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Chen Zhe; Ito, Kenji [Metrology Institute of Japan (MIJ), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565 (Japan); Yanagishita, Hiroshi [Research Institute for Innovation in Sustainable Chemistry (ISC), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565 (Japan); Tsutsui, Takuro; Uedono, Akira [Division of Applied Physics, Faculty of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Hayashizaki, Noriyosu [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Meguro, Tokyo 152-8850 (Japan)

    2012-07-02

    A pulsed, slow positron beam, with a diameter of 200 {mu}m, was extracted into air through a thin SiN window of an atmospheric positron probe microanalyzer (PPMA), and used to measure the ortho-positronium lifetimes {tau} in polyvinyl alcohol and polycaprolactam sub-{mu}m-thick films. By measuring the variation of {tau} as a function of relative humidity, the effect of water molecules on the hole sizes, deduced from {tau}, was examined for the films with consideration to the chain mobility. The results demonstrate the usefulness of the atmospheric PPMA to the in-situ characterization of nanoscopic holes in thin films under practical conditions.

  14. Measurement of the D(0), D(+), and D(+)s meson lifetimes

    E-print Network

    Baringer, Philip S.

    1989-01-01

    of the beams due to the synchrotron radiation. The same Bhabha-scattering events that were used to determine the beam positions were used to mea- sure the beam size. The x and y dimensions of the beam can be obtained by measuring the impact-parameter dis...- tributions of the horizontal and the vertical tracks. The impact-parameter distributions of the tracks which make angles with the x or y axis of less than 0.1 rad are shown in Fig. 19. The standard deviations of these distributions, fitted by a Gaussian shape...

  15. THz Measurement of Scattering Lifetime in CaRuO3 Films

    NASA Astrophysics Data System (ADS)

    Kamal, Saeid; Dodge, J. Steven; Kim, Dong-Min; Eom, Chang-Beom

    2004-03-01

    We have studied the electrodynamics properties of CaRuO3 films using time domain THz spectroscopy techniques. The CaRuO3 films were grown on vicinal NdGaO3 substrates with 4 degree miscut which allows growth of high quality films with low residual resistivity. We have measured the complex conductivity as a function of temperature from 5 K to 300 K and as a function of frequency in the range of 200 GHz to 1 THz. Results are discussed in the framework of extended Drude model.

  16. Measurement of Lifetime and Decay-Width Difference in B0s -> J/psi phi Decays

    SciTech Connect

    Aaltonen, : T.

    2007-12-01

    The authors measure the mean lifetime, {tau} = 2/({Lambda}{sub L} + {Lambda}{sub H}), and the decay-width difference, {Delta}{Lambda} = {Lambda}{sub L} - {Lambda}{sub H}, of the light and heavy mass eigenstates of the B{sub s}{sup 0} meson, B{sub sL}{sup 0} and B{sub sH}{sup 0}, in B{sub s}{sup 0} {yields} J/{psi}{phi} decays using 1.7 fb{sup -1} of data collected with the CDF II detector at the Fermilab Tevatron p{bar p} collider. Assuming CP conservation, a good approximation for the B{sub s}{sup 0} system in the standard model, they obtain {Delta}{Lambda} = 0.076{sub -0.063}{sup +0.059}(stat.) {+-} 0.006(syst.) ps{sup -1} and {tau} = 1.52 {+-} 0.04(stat.) {+-} 0.02(syst.) ps, the most precise measurements to date. The constraints on the weak phase and {Delta}{Lambda} are consistent with CP conservation.

  17. DSA lifetime measurements of 124Cs and the time-reversal symmetry

    NASA Astrophysics Data System (ADS)

    Grodner, E.; Pasternak, A. A.; Srebrny, J.; Kowalczyk, M.; Mierzejewski, J.; Kisieli?ski, M.; Decowski, P.; Droste, Ch; Perkowski, J.; Abraham, T.; Andrzejewski, J.; Hady?ska-Kl?k, K.; Janiak, ?.; Kasparek, A.; Marchlewski, T.; Napiorkowski, P.; Samorajczyk, J.

    2012-09-01

    A hypothesis of the chiral symmetry breaking opened a new opportunity for the study of spontaneous time-reversal symmetry breaking in an atomic nucleus. The occurence of chirality has been found in 126,128Cs nuclei for which specific electromagnetic selection rules have been found in Doppler Shift Attenuation experiments. Here, recent DSA measurements in the 124Cs nucleus are presented. The 124Cs nucleus was produced in the 114Cd(14N,4n)124Cs reaction at Heavy Ion Laboratory of the University of Warsaw. The obtained results agree with basic expectations deduced from the chiral symmetry breaking. A connection between the chirality phenomenon and the time-reversal symmetry is discussed and a possibility of using chiral doublets for studies of fundamental time reversal symmetry is suggested.

  18. Cosmic ray propagation time scales: lessons from radioactive nuclei and positron data

    SciTech Connect

    Blum, Kfir, E-mail: kfir.blum@weizmann.ac.il [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 76100 (Israel)

    2011-11-01

    We take a fresh look at high energy radioactive nuclei data reported in the 90's and at the positron data recently reported by PAMELA. Our aim is to study the model independent implications of these data for the propagation time scales of cosmic rays in the Galaxy. Considering radioactive nuclei, using decaying charge to decayed charge ratios — the only directly relevant data available at relativistic energies — we show that a rigidity independent residence time is consistent with observations. The data for all nuclei can be described by f{sub s,i} = (t{sub i}/100 Myr){sup 0.7}, where f{sub s,i} is the suppression of the flux due to decay and t{sub i} is the observer frame lifetime for nucleus specie i. Considering positron measurements, we argue that the positron flux is consistent with a secondary origin. Comparing the positron data with radioactive nuclei at the same energy range, we derive an upper bound on the mean electromagnetic energy density traversed by the positrons, U-bar {sub T} < 1.25 eV/cm{sup 3} at a rigidity of R = 40 GV. Charge ratio measurements within easy reach of the AMS-02 experiment, most notably a determination of the Cl/Ar ratio extending up to R ? 100 GV, will constrain the energy dependence of the positron cooling time. Such constraints can be used to distinguish between different propagation scenarios, as well as to test the secondary origin hypothesis for the positrons in detail.

  19. Effective lifetime measurements in the B[0 over s]--> K+K?, B[superscript 0]-->K+?? and B[0 over s]-->?+K? decays

    E-print Network

    LHCb collaboration

    Measurements of the effective lifetimes in the B[0 over s]?K+K?, B0?K+??B[superscript 0]?K+?? and B[0 over s]??+K? decays are presented using 1.0 fb?11.0 fb[superscript ?1] of pp collision data collected at a centre-of-mass ...

  20. Measurement of D-D-bar mixing using the ratio of lifetimes for the decays D-->K- pi + and K+K-

    E-print Network

    Fisher, Peter H.

    We measure the rate of D0-D[over-bar] 0 mixing with the observable yCP=(?Kpi/?KK)-1, where ?KK and ?Kpi are, respectively, the mean lifetimes of CP-even D0-->K+K- and CP-mixed D0-->K-pi+ decays, using a data sample of ...

  1. Collinear Laser-Beam Ion-Beam Measurement of the Mean Lifetime of the Ar Ii 4p'2f-Degrees-7/2 Level 

    E-print Network

    Jin, J.; Church, David A.

    1993-01-01

    The mean lifetime tau of the 4p'F-2(7/2)-degrees level of Ar II has been measured using a variant of the collinear laser-beam-fast-ion-beam spectroscopy technique. Our variant requires no mechanical motion or laser frequency tuning. The result...

  2. Measurement of B-meson lifetimes using fully reconstructed B decays produced in ppbar collisions at (s)=1.8 TeV

    NASA Astrophysics Data System (ADS)

    Acosta, D.; Affolder, T.; Akimoto, H.; Albrow, M. G.; Ambrose, D.; Amidei, D.; Anikeev, K.; Antos, J.; Apollinari, G.; Arisawa, T.; Artikov, A.; Asakawa, T.; Ashmanskas, W.; Azfar, F.; Azzi-Bacchetta, P.; Bacchetta, N.; Bachacou, H.; Badgett, W.; Bailey, S.; de Barbaro, P.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Baroiant, S.; Barone, M.; Bauer, G.; Bedeschi, F.; Belforte, S.; Bell, W. H.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Bensinger, J.; Beretvas, A.; Berge, J. P.; Berryhill, J.; Bhatti, A.; Binkley, M.; Bisello, D.; Bishai, M.; Blair, R. E.; Blocker, C.; Bloom, K.; Blumenfeld, B.; Blusk, S. R.; Bocci, A.; Bodek, A.; Bolla, G.; Bonushkin, Y.; Bortoletto, D.; Boudreau, J.; Brandl, A.; van den Brink, S.; Bromberg, C.; Brozovic, M.; Brubaker, E.; Bruner, N.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Byon-Wagner, A.; Byrum, K. L.; Cabrera, S.; Calafiura, P.; Campbell, M.; Carithers, W.; Carlson, J.; Carlsmith, D.; Caskey, W.; Castro, A.; Cauz, D.; Cerri, A.; Chan, A. W.; Chang, P. S.; Chang, P. T.; Chapman, J.; Chen, C.; Chen, Y. C.; Cheng, M.-T.; Chertok, M.; Chiarelli, G.; Chirikov-Zorin, I.; Chlachidze, G.; Chlebana, F.; Christofek, L.; Chu, M. L.; Chung, J. Y.; Chung, W.-H.; Chung, Y. S.; Ciobanu, C. I.; Clark, A. G.; Coca, M.; Colijn, A. P.; Connolly, A.; Convery, M.; Conway, J.; Cordelli, M.; Cranshaw, J.; Culbertson, R.; Dagenhart, D.; D'Auria, S.; Dejongh, F.; dell'Agnello, S.; dell'Orso, M.; Demers, S.; Demortier, L.; Deninno, M.; Derwent, P. F.; Devlin, T.; Dittmann, J. R.; Dominguez, A.; Donati, S.; D'Onofrio, M.; Dorigo, T.; Dunietz, I.; Eddy, N.; Einsweiler, K.; Elias, J. E.; Engels, E.; Erbacher, R.; Errede, D.; Errede, S.; Fan, Q.; Fang, H.-C.; Feild, R. G.; Fernandez, J. P.; Ferretti, C.; Field, R. D.; Fiori, I.; Flaugher, B.; Foster, G. W.; Franklin, M.; Freeman, J.; Friedman, J.; Fukui, Y.; Furic, I.; Galeotti, S.; Gallas, A.; Gallinaro, M.; Gao, T.; Garcia-Sciveres, M.; Garfinkel, A. F.; Gatti, P.; Gay, C.; Gerdes, D. W.; Gerstein, E.; Giannetti, P.; Giolo, K.; Giordani, M.; Giromini, P.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldstein, J.; Gorelov, I.; Goshaw, A. T.; Gotra, Y.; Goulianos, K.; Green, C.; Grim, G.; Gris, P.; Grosso-Pilcher, C.; Guenther, M.; Guillian, G.; Guimaraes da Costa, J.; Haas, R. M.; Haber, C.; Hahn, S. R.; Hall, C.; Handa, T.; Handler, R.; Happacher, F.; Hara, K.; Hardman, A. D.; Harris, R. M.; Hartmann, F.; Hatakeyama, K.; Hauser, J.; Heinrich, J.; Heiss, A.; Herndon, M.; Hill, C.; Hocker, A.; Hoffman, K. D.; Hollebeek, R.; Holloway, L.; Huffman, B. T.; Hughes, R.; Huston, J.; Huth, J.; Ikeda, H.; Incandela, J.; Introzzi, G.; Ivanov, A.; Iwai, J.; Iwata, Y.; James, E.; Jones, M.; Joshi, U.; Kambara, H.; Kamon, T.; Kaneko, T.; Karagoz Unel, M.; Karr, K.; Kartal, S.; Kasha, H.; Kato, Y.; Keaffaber, T. A.; Kelley, K.; Kelly, M.; Kennedy, R. D.; Kephart, R.; Khazins, D.; Kikuchi, T.; Kilminster, B.; Kim, B. J.; Kim, D. H.; Kim, H. S.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kirby, M.; Kirk, M.; Kirsch, L.; Klimenko, S.; Koehn, P.; Kondo, K.; Konigsberg, J.; Korn, A.; Korytov, A.; Kovacs, E.; Kroll, J.; Kruse, M.; Krutelyov, V.; Kuhlmann, S. E.; Kurino, K.; Kuwabara, T.; Laasanen, A. T.; Lai, N.; Lami, S.; Lammel, S.; Lancaster, J.; Lancaster, M.; Lander, R.; Lath, A.; Latino, G.; Lecompte, T.; Lee, K.; Lee, S. W.; Leone, S.; Lewis, J. D.; Lindgren, M.; Liss, T. M.; Liu, J. B.; Liu, T.; Liu, Y. C.; Litvintsev, D. O.; Lobban, O.; Lockyer, N. S.; Loken, J.; Loreti, M.; Lucchesi, D.; Lukens, P.; Lusin, S.; Lyons, L.; Lys, J.; Madrak, R.; Maeshima, K.; Maksimovic, P.; Malferrari, L.; Mangano, M.; Manca, G.; Mariotti, M.; Martignon, G.; Martin, A.; Martin, V.; Matthews, J. A.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; Menguzzato, M.; Menzione, A.; Merkel, P.; Mesropian, C.; Meyer, A.; Miao, T.; Miller, R.; Miller, J. S.; Minato, H.; Miscetti, S.; Mishina, M.; Mitselmakher, G.; Miyazaki, Y.; Moggi, N.; Moore, E.; Moore, R.; Morita, Y.; Moulik, T.; Mulhearn, M.; Mukherjee, A.; Muller, T.; Munar, A.; Murat, P.; Murgia, S.; Nachtman, J.; Nagaslaev, V.; Nahn, S.; Nakada, H.; Nakano, I.; Nelson, C.; Nelson, T.; Neu, C.; Neuberger, D.; Newman-Holmes, C.; Ngan, C.-Y.; Niu, H.; Nodulman, L.; Nomerotski, A.; Oh, S. H.; Oh, Y. D.; Ohmoto, T.; Ohsugi, T.; Oishi, R.; Okusawa, T.; Olsen, J.; Orejudos, W.; Pagliarone, C.; Palmonari, F.; Paoletti, R.; Papadimitriou, V.; Partos, D.; Patrick, J.; Pauletta, G.; Paulini, M.; Paus, C.; Pellett, D.; Pescara, L.; Phillips, T. J.; Piacentino, G.; Pitts, K. T.; Pompos, A.; Pondrom, L.; Pope, G.; Pratt, T.; Prokoshin, F.; Proudfoot, J.; Ptohos, F.; Pukhov, O.; Punzi, G.; Rakitine, A.; Ratnikov, F.; Reher, D.; Reichold, A.; Renton, P.; Ribon, A.; Riegler, W.; Rimondi, F.; Ristori, L.; Riveline, M.; Robertson, W. J.; Rodrigo, T.

    2002-05-01

    We present an improved measurement of b-meson lifetimes using fully reconstructed B-decays produced in ppbar collisions at (s)=1.8 TeV, using 114 pb-1 of data collected at the Collider Detector at Fermilab. We obtain ?(B+)=1.636+/-0.058(stat)+/-0.025(syst) ps, ?(B0)=1.497+/-0.073(stat)+/-0.032(syst) ps and for the lifetime ratio ?(B+)/?(B0)=1.093+/-0.066(stat)+/-0.028(syst).

  3. Lifetime Measurement of the 6.79 MeV State in 15O to Help Constrain the 14N(p,gamma)15O Reaction Rate

    NASA Astrophysics Data System (ADS)

    Galinski, Naomi; Sjue, Sky; Davids, Barry; Kanungo, Rituparna; Ruiz, Chris; Hager, Ulrike

    2014-03-01

    The 14N(p, ?)15O reaction is the slowest reaction in the CNO cycle. The rate of this reaction is an important input into calculating the ages of globular cluster stars, determining the primordial core composition of our Sun and affects the amount of He ash produced in H burning shells in red giant stars and hence the nucleosynthesis of heavier elements. The largest remaining uncertainty in calculating the reaction rate is the lifetime of the 6.79 MeV excited state of 15O. We report an upper limit of 1.84 fs on this lifetime. In addition we measured the lifetime of the 6.86 MeV state of 15O to be 13.3-1. 2 + 0 . 8 fs. I am a recipient of a DOC-FFORTE-fellowship of the Austrian Academy of Sciences and thank them for their generous support.

  4. Lifetime measurements of the neutron-rich N = 30 isotones 50Ca and 51Sc: orbital dependence of effective charges in the fp shell.

    PubMed

    Valiente-Dobón, J J; Mengoni, D; Gadea, A; Farnea, E; Lenzi, S M; Lunardi, S; Dewald, A; Pissulla, Th; Szilner, S; Broda, R; Recchia, F; Algora, A; Angus, L; Bazzacco, D; Benzoni, G; Bizzeti, P G; Bizzeti-Sona, A M; Boutachkov, P; Corradi, L; Crespi, F; de Angelis, G; Fioretto, E; Görgen, A; Gorska, M; Gottardo, A; Grodner, E; Guiot, B; Howard, A; Królas, W; Leoni, S; Mason, P; Menegazzo, R; Montanari, D; Montagnoli, G; Napoli, D R; Obertelli, A; Paw?at, T; Pollarolo, G; Rubio, B; Sahin, E; Scarlassara, F; Silvestri, R; Stefanini, A M; Smith, J F; Steppenbeck, D; Ur, C A; Wady, P T; Wrzesi?ski, J; Maglione, E; Hamamoto, I

    2009-06-19

    The lifetimes of the first excited states of the N = 30 isotones (50)Ca and (51)Sc have been determined using the Recoil Distance Doppler Shift method in combination with the CLARA-PRISMA spectrometers. This is the first time such a method is applied to measure lifetimes of neutron-rich nuclei populated via a multinucleon transfer reaction. This extends the lifetime knowledge beyond the f_{7/2} shell closure and allows us to derive the effective proton and neutron charges in the fp shell near the doubly magic nucleus (48)Ca, using large-scale, shell-model calculations. These results indicate an orbital dependence of the core polarization along the fp shell. PMID:19659003

  5. Positron spectroscopy of defects in submicrocrystalline nickel after low-temperature annealing

    NASA Astrophysics Data System (ADS)

    Kuznetsov, P. V.; Mironov, Yu. P.; Tolmachev, A. I.; Bordulev, Yu. S.; Laptev, R. S.; Lider, A. M.; Korznikov, A. V.

    2015-02-01

    Using the method of measuring the positron lifetime spectra and Doppler broadening annihilation line spectroscopy, the annealing of defects in submicrocrystalline nickel produced by equal channel angular pressing has been studied. In as-prepared samples, the positrons are trapped by dislocation defects and vacancy complexes inside crystallites. The size of vacancy complexes decreases with increasing annealing temperature in the interval ? T = 20-300°C. However, at T = 360°C, the complexes start growing again. The dependence of S-parameter on W-parameter derived from the Doppler broadening spectroscopy has two parts with different inclinations to axes that correspond to different types of primary centers of positron trapping in submicrocrystalline nickel. It has been elucidated that, at recovery stage in the temperature interval ? T = 20-180°C, the main centers of positron trapping are low-angle boundaries enriched by impurities, while at in situ recrystallization stage in the temperature interval ? T = 180-360°C, the primary centers of positron trapping are low-angle boundaries.

  6. Positron Annihilation Spectroscopy and Small Angle Neutron Scattering Characterization of Nanostructural Features in Irradiated Fe-Cu-Mn Alloys

    SciTech Connect

    Wirth, B D; Asoka-Kumar, P; Howell, R H; Odette, G R; Sterne, P A

    2001-01-01

    Radiation embrittlement of nuclear reactor pressure vessel steels results from a high number density of nanometer sized Cu-Mn-Ni rich precipitates (CRPs) and sub-nanometer matrix features, thought to be vacancy-solute cluster complexes (VSC). However, questions exist regarding both the composition of the precipitates and the defect character and composition of the matrix features. We present results of positron annihilation spectroscopy (PAS) and small angle neutron scattering (SANS) characterization of irradiated and thermally aged Fe-Cu and Fe-Cu-Mn alloys. These complementary techniques provide insight into the composition and character of both types of nanoscale features. The SANS measurements indicate populations of CRPs and VSCs in both alloys. The CRPs are c