Science.gov

Sample records for nuclear g-factor measurements

  1. Towards high precision measurements of nuclear g-factors for the Be isotopes

    NASA Astrophysics Data System (ADS)

    Takamine, A.; Wada, M.; Okada, K.; Ito, Y.; Schury, P.; Arai, F.; Katayama, I.; Imamura, K.; Ichikawa, Y.; Ueno, H.; Wollnik, H.; Schuessler, H. A.

    2016-06-01

    We describe the present status of future high-precision measurements of nuclear g-factors utilizing laser-microwave double and laser-microwave-rf triple resonance methods for online-trapped, laser-cooled radioactive beryllium isotope ions. These methods have applicability to other suitably chosen isotopes and for beryllium show promise in deducing the hyperfine anomaly of 11Be with a sufficiently high precision to study the nuclear magnetization distribution of this one-neutron halo nucleus in a nuclear-model-independent manner.

  2. Nuclear g-factor measurements of the (9/2){sup -} and (21/2){sup -} isomeric states in {sup 173}Ta

    SciTech Connect

    Thakur, P.; Kumar, V.; Bhati, A. K.; Bedi, S. C.; Singh, R. P.; Bhowmik, R. K.; Stuchbery, A. E.

    2006-09-15

    The nuclear g-factors of the one-quasiparticle isomeric state (9/2){sup -} at 165.8 keV and the three-quasiparticle isomeric state (21/2){sup -} at 1713.2 keV in {sup 173}Ta nuclei have been measured using the time differential perturbed angular distribution technique. The nuclear reaction {sup 165}Ho({sup 12}C, 4n{gamma}){sup 173}Ta was used to populate these isomeric states, and the recoiling {sup 173}Ta nuclei were implanted into a thick tantalum backing in the presence of a 7.04(4) kG external magnetic field. The measured value g((9/2){sup -}) = +0.591(18) shows that the (9/2){sup -} isomeric state is not a pure single-particle state but may have a collective contribution due to the octupole excitation of the core. Based on the measured value g((21/2){sup -}) = + 0.620(15) and multi-quasiparticle calculations, the (21/2){sup -} isomeric state is assigned a mixed configuration: {pi}{sup 3}((9/2){sup -}[514], (7/2){sup +}[404] (5/2){sup +}[402]) (39%) and {pi}{sup 1}((7/2){sup +}[404])(multiply-in-circle sign) {nu}{sup 2}((7/2){sup -}[514], (7/2){sup +}[633]) (61%)

  3. Nuclear g-factor measurement for the low-lying state in ^109Rh using On-line TDPAC technique and RF-IGISOL technique

    NASA Astrophysics Data System (ADS)

    Miyashita, Yuji; Ouchi, Hiroyuki; Izumi, Sayaka; Sasaki, Ayako; Sato, Nozomi; Tateoka, Miki; Hoshino, Sayo; Nagano, Tetsuya; Yamashita, Wataru; Yamazaki, Akiyoshi; Shimada, Kenzi; Ishida, Takashi; Wakui, Takashi; Shinozuka, Tsutomu; Tanigaki, Minoru

    2009-10-01

    To extend the studies on neutron-rich nuclei, we have developed an RF-IGISOL technique, which is combination of the gas catcher technique and the electrical field guiding technique with a large volume gas cell. As the first step to such approach, we are planning and trying the systematic measurement of g-factor in the neutron rich nuclei extracted as an radioactive beam from our RF-IGISOL at Tohoku University. The g-factor measurement for the low-lying state of ^109Rh (Ex = 225.98 keV, T1/2 = 1.66 μs) is the first on-line experiment with our RF-IGISOL system. The g-factor for this state has been determined to be g = 0.78 ^+0.17-0.03 μN by the on-line TDPAC method. In this contribution, the details of experimental results will be reported.

  4. Nuclear-polarization correction to the bound-electron g factor in heavy hydrogenlike ions.

    PubMed

    Nefiodov, A V; Plunien, G; Soff, G

    2002-08-19

    The influence of nuclear polarization on the bound-electron g factor in heavy hydrogenlike ions is investigated. Numerical calculations are performed for the K- and L-shell electrons taking into account the dominant virtual nuclear excitations. This determines the ultimate limit for tests of QED utilizing measurements of the bound-electron g factor in highly charged ions. PMID:12190457

  5. Nuclear and QED corrections to the bound-electron g factor

    NASA Astrophysics Data System (ADS)

    Zatorski, Jacek; Oreshkina, Natalia S.; Keitel, Christoph H.; Harman, Zoltán

    2012-06-01

    We calculate nuclear shape and quantum electrodynamic corrections to the g factor of a bound electron [1,2]. These theoretical studies are motivated by the current improvement of experimental possibilities: on the one hand, in a recent Penning trap measurement [2], the g factor of ^28Si^13+ has been determined with an unprecedented 5 .10-10 relative uncertainty. A novel experimental technique will further improve accuracy to the 10-11 level. On the other hand, experiments with ions as heavy as ^238U^91+ will be performed soon at the HITRAP-FAIR facility. For such heavy ions, nuclear effects play an important role. The leading relativistic nuclear deformation correction has been derived analytically and also its influence on one-loop quantum electrodynamic terms has been evaluated. We present results for medium- and high-Z hydrogenlike ions, which become significant already for mid-Z ions, and for very heavy elements it even reaches the 10-6 level, as we show in [1].[4pt] [1] J. Zatorski, N. S. Oreshkina, C. H. Keitel, and Z. Harman, Phys. Rev. Lett., in press; arXiv:1110.3330 [2] S. Sturm, A. Wagner, B. Schabinger, J. Zatorski, et al., Phys. Rev. Lett. 107, 023002 (2011).

  6. g-factor measurements of isomeric states in 174W

    NASA Astrophysics Data System (ADS)

    Rocchini, M.; Nannini, A.; Benzoni, G.; Melon, B.; John, P. R.; Ur, C. A.; Avigo, R.; Bazzacco, D.; Blasi, N.; Bocchi, G.; Bottoni, S.; Bracco, A.; Camera, F.; Ceruti, S.; Crespi, F. C. L.; Georgiev, G.; Giaz, A.; Gottardo, A.; Leoni, S.; Menegazzo, R.; Mengoni, D.; Michelagnoli, C.; Million, B.; Modamio, V.; Morales, A. I.; Napoli, D. R.; Ottanelli, M.; Pellegri, L.; Perego, A.; Valiente-Dobon, J. J.; Wieland, O.

    2016-05-01

    The experimental setup GAMIPE used for gyro magnetic factor measurements at Laboratori Nazionali di Legnaro and a recent experimental work regarding K-isomers in 174W are described. Aim of the experiment is to study the detailed structure of the isomeric states wave functions, by the measurement of the magnetic dipole moments. This piece of information can provide interesting hints for theoretical models. Preliminary results concerning the population of the isomers of interest and half-lives are presented.

  7. Measurement of the anomalous neutron orbital g factor in /sup 190//sup m/Os

    SciTech Connect

    Beck, R.; Eder, R.; Hagn, E.; Zech, E.

    1987-12-28

    The magnetic moment of /sup 190//sup m/Os (I/sup ..pi../ = 10/sup -/; T/sub 1/2/ = 9.9 min; E = 1705 keV configuration chemically bondn/sub 1/9/2(505)n/sub 2/11/2(615)>/sub 10-/ has been measured with the new technique of reorientation--nuclear-orientation. As the spin contributions of the two neutrons to the magnetic moment cancel almost completely, it is possible to determine the anomalous neutron orbital g factor directly. The result, -0.12less than or equal todeltag/sub 1/(n)less than or equal to0.07 (90% confidence level) tends to be larger than deltag/sub 1/(n)approx. =-0.05 adopted up to now.

  8. Single particle signatures in high-spin, quasicontinuum, states in {sup 193,194}Hg from g-factor measurements.

    SciTech Connect

    Weissman, L.; Mayer, R. H.; Kumbartzki, G.; Benczer-Koller, N.; Broude, C.; Cizewski, J. A.; Hass, M.; Holden, J.; Janssens, R. V. F.; Lauritsen, T.; Lee, I. Y.; Macchiavelli, A. O.; McNabb, D. P.; Satteson, M.; Physics; Weizmann Inst. of Science; Rutgers Univ.; LBNL

    1999-01-14

    The average g factors of high spin, high-excitation energy, quasicontinuum structures in {sup 194,193}Hg were measured by observing the precessions of the angular distributions of {gamma}-ray transitions in several normal-deformation bands that coalesce in the decay of the entry distribution of states. The average g factors of the states leading to the three main bands in the {sup 193,194}Hg isotopes were: {l_angle}g({sup 193}Hg){r_angle}=+0.19(1) and {l_angle}g({sup 194}Hg){r_angle}=+0.26(1), respectively. These average g factors are smaller than the average of the g factors of the high energy states in the three superdeformed bands of {sup 194}Hg, {l_angle}g(SD; {sup 194}Hg){r_angle}=+0.41(8). While the nucleus in the superdeformed well behaves like a rigid rotor, the present results demonstrate the important role played by multiple, quasiparticle neutron configurations in the structure of normal-deformation, highly-excited nuclear states.

  9. Recoil in vacuum for Te ions: Calibration, models, and applications to radioactive-beam g-factor measurements

    SciTech Connect

    Stuchbery, A. E.; Stone, N. J.

    2007-09-15

    In the light of new g factor results for the stable isotopes between {sup 122}Te and {sup 130}Te, the calibration and modeling of the recoil-in-vacuum (RIV) interaction for Te ions is reexamined, and the recent radioactive-beam g factor measurement on {sup 132}Te by the RIV technique is reevaluated. The implications for further RIV g-factor measurements in the {sup 132}Sn region are discussed.

  10. New reaction chamber for transient field g-factor measurements with radioactive ion beams

    NASA Astrophysics Data System (ADS)

    Illana, A.; Perea, A.; Nácher, E.; Orlandi, R.; Jungclaus, A.

    2015-06-01

    A new reaction chamber has been designed and constructed to measure g-factors of short-lived excited states using the Transient Field technique in combination with Coulomb excitation in inverse kinematics. In this paper we will discuss several important aspects which have to be considered in order to successfully carry out this type of measurement with radioactive ion beams, instead of the stable beams used in a wide range of experiments in the past. The technical solutions to the problems arising from the use of such radioactive beams will be exposed in detail and the first successful experiment using the new chamber in combination with MINIBALL cluster detectors at REX-ISOLDE (CERN) will be reported on.

  11. Lifetime and g-factor measurements of excited states using Coulomb excitation and alpha transfer reactions

    NASA Astrophysics Data System (ADS)

    Guevara, Z. E.; Torres, D. A.

    2016-07-01

    In this contribution the challenges in the use of a setup to simultaneously measure lifetimes and g-factor values will be presented. The simultaneous use of the transient field technique and the Doppler Shift Attenuation Method, to measure magnetic moments and lifetimes respectively, allows to obtain a complete characterization of the currents of nucleons and the deformation in excited states close to the ground state. The technique is at the moment limited to Coulomb excitation and alpha-transfer reactions, what opens an interesting perspective to consider this type of experiments with radioactive beams. The use of deep-inelastic and fusion-evaporation reactions will be discussed. An example of a setup that makes use of a beam of 106Cd to study excited states of 110Sn and the beam nuclei itself will be presented.

  12. Measuring g factors of 41+ and 61+ states in even-even nuclei with 80

    NASA Astrophysics Data System (ADS)

    Torres, Diego; Benczer-Koller, N.; Kumbartzki, G.; Gürdal, G.; Sharon, Y. Y.; Zamick, L.; Speidel, K.-H.; Ilie, G.; Heinz, A.; Ahn, T.; Werner, V.; Robinson, S. J. Q.

    2011-10-01

    The measurement of g factors of the low lying excited states in even-even nuclei with lifetimes of the order of 1 to 50 picoseconds presents challenging questions for both theory and experiment. The experimental determination of accurate g factor values uses the transient field technique in inverse kinematics and requires an understanding of the reaction mechanism used to populate the final states. So far, the main method of excitation has been Coulomb excitation. More recently, alpha transfer from a 12C target to selected beams made it possible to populate states in nuclei not available as stable beams. This method has been successful for lighter nuclei up to A ~70. A comparison between Coulomb excitation and alpha transfer reactions will be presented. The experiments used the Tandem at the Wright Nuclear Structure Laboratory at Yale University. Preliminary results for the 100Pd, 96Ru and 86Sr nuclei will be presented. Experimental challenges for future experiments will be discussed. Supported in part by the DOE and the NSF.

  13. Optical detection of anisotropic g-factor and nuclear spin polarization in a single CdTe quantum well

    NASA Astrophysics Data System (ADS)

    Yan, Li-Ping; Kurosawa, Masahiro; Hsu, Wei-Ting; Chang, Wen-Hao; Adachi, Satoru

    2015-03-01

    Longitudinal and in-plane electron g-factors, and a nuclear spin polarization (NSP) have been evaluated precisely in a CdTe/Cd0.85Mg0.15Te single quantum well by using the time-resolved Kerr rotation and double lock-in detection techniques. Resident electron spin polarization (RESP) was formed via the negative trion formation and recombination, and RESP gave rise to NSP in an oblique magnetic field configuration. We observed the effective nuclear field of a few mT which was weak compared with that in III-V semiconductor nanostructures as expected, but the nuclear field can be converted to the maximal NSP of 12% in Faraday geometry.

  14. Low-energy structure of the even-A {sup 96-104}Ru isotopes via g-factor measurements

    SciTech Connect

    Taylor, M. J.; Bentley, M. A.; Guerdal, G.; Kumbartzki, G.; Benczer-Koller, N.; Sharon, Y. Y.; Stuchbery, A. E.; Berant, Z.; Casperson, R. J.; Casten, R. F.; Heinz, A.; Ilie, G.; McCutchan, E. A.; Qian, J.; Werner, V.; Williams, E.; Winkler, R.; Luettke, R.; Shoraka, B.

    2011-04-15

    The transient-field-perturbed angular correlation technique was used with Coulomb excitation in inverse kinematics to perform a systematic measurement of the g factors of the first excited 2{sub 1}{sup +} states in the stable even-A isotopes {sup 96-104}Ru. The measurements have been made relative to one another under matched kinematic conditions and include a measurement of g(2{sub 1}{sup +})=+0.47(3) in {sup 96}Ru.

  15. New measurement of the {sup 68}Zn(4{sub 1}{sup +}) g factor combined with a reanalysis of previous data

    SciTech Connect

    Moschner, K.; Bernards, C.; Bettermann, L.; Speidel, K.-H.; Leske, J.; Bauer, C.; Moeller, T.; Honma, M.; Maier-Komor, P.; Muecher, D.

    2010-07-15

    We have remeasured and have redetermined the g factor for the 4{sub 1}{sup +} state in {sup 68}Zn following inconsistencies between earlier measurements and a recent result. We have reanalyzed several former measurements by applying an alternative analysis procedure, which allows for determining the precession effect separately for each gamma detector implying less uncertainties in the background subtraction for the relevant spectra. In addition, all measured g-factor and B(E2) data for the first 2{sup +} and 4{sup +} states in all stable even-A Zn isotopes and the radioactive {sup 62}Zn, are compared with new large-scale shell model calculations based on the most advanced effective interaction in the fpg-shell model space.

  16. First direct measurements of {bold {ital g}} factors of the three superdeformed bands of {sup 194}Hg

    SciTech Connect

    Mayer, R.H.; Kumbartzki, G.; Benczer-Koller, N.; Cizewski, J.A.; Holden, J.; McNabb, D.P.; Satteson, M.; Weissman, L.; Broude, C.; Hass, M.; Janssens, R.V.; Lauritsen, T.; Lee, I.Y.; Macchiavelli, A.O.

    1998-11-01

    The average {ital g} factors of the high-energy states of the three superdeformed bands in {sup 194}Hg were determined {ital directly} in a transient field experiment. The reaction {sup 150}Nd({sup 48}Ca,4n){sup 194}Hg at a beam energy of 203 MeV was used to provide recoiling reaction product nuclei with sufficient velocity to traverse a gadolinium ferromagnetic layer. The resulting {ital g} factors g(SD1)=0.36(10), g(SD2)=0.41(20), and g(SD3)=0.71(26) are in agreement with cranked Hartree-Fock calculations as well as with the picture of a rigid rotation for which g=Z/A. thinsp {copyright} {ital 1998} {ital The American Physical Society}

  17. Vanishing electron g factor and long-lived nuclear spin polarization in weakly strained nanohole-filled GaAs/AlGaAs quantum dots

    NASA Astrophysics Data System (ADS)

    Ulhaq, A.; Duan, Q.; Zallo, E.; Ding, F.; Schmidt, O. G.; Tartakovskii, A. I.; Skolnick, M. S.; Chekhovich, E. A.

    2016-04-01

    GaAs/AlGaAs quantum dots grown by in situ droplet etching and nanohole in-filling offer a combination of strong charge confinement, optical efficiency, and high spatial symmetry advantageous for polarization entanglement and spin-photon interface. Here, we study experimentally electron and nuclear spin properties of such dots. We find nearly vanishing electron g factors (ge<0.05 ), providing a potential route for electrically driven spin control schemes. Optical manipulation of the nuclear spin environment is demonstrated with nuclear spin polarization up to 65 % achieved. Nuclear magnetic resonance spectroscopy reveals two distinct types of quantum dots: with tensile and with compressive strain along the growth axis. In both types of dots, the magnitude of strain ɛb<0.02 % is nearly three orders of magnitude smaller than in self-assembled dots: On the one hand, this provides a route for eliminating a major source of electron spin decoherence arising from nuclear quadrupolar interactions, and on the other hand such strain is sufficient to suppress nuclear spin diffusion leading to a stable nuclear spin bath with nuclear spin lifetimes exceeding 500 s. The spin properties revealed in this work make this new type of quantum dot an attractive alternative to self-assembled dots for the applications in quantum information technologies.

  18. Magnetism of an excited self-conjugate nucleus: precise measurement of the g factor of the 2(1)(+) state in (24)Mg.

    PubMed

    Kusoglu, A; Stuchbery, A E; Georgiev, G; Brown, B A; Goasduff, A; Atanasova, L; Balabanski, D L; Bostan, M; Danchev, M; Detistov, P; Gladnishki, K A; Ljungvall, J; Matea, I; Radeck, D; Sotty, C; Stefan, I; Verney, D; Yordanov, D T

    2015-02-13

    A precise measurement of the g factor of the first-excited state in the self-conjugate (N=Z) nucleus (24)Mg is performed by a new time-differential recoil-in-vacuum method based on the hyperfine field of hydrogenlike ions. Theory predicts that the g factors of such states, in which protons and neutrons occupy the same orbits, should depart from 0.5 by a few percent due to configuration mixing and meson-exchange effects. The experimental result, g=0.538±0.013, is in excellent agreement with recent shell-model calculations and shows a departure from 0.5 by almost 3 standard deviations, thus achieving, for the first time, the precision and accuracy needed to test theory. Proof of the new method opens the way for wide applications including measurements of the magnetism of excited states of exotic nuclei produced as radioactive beams. PMID:25723214

  19. Measurements of the g-factors of the 2^+1 states in ^82Sr (25.3 d) and ^90Sr (28.8 y)

    NASA Astrophysics Data System (ADS)

    Rice, Samantha; Naimark, Samuel; Kumbartzki, Gerfried; Benczer-Koller, Noemie

    2012-10-01

    Magnetic moments and lifetimes of the 2^+1 states in ^84-88Sr isotopes were measured via the transient field technique and Coulomb excitation in inverse kinematics. The pending experiment will use ^78,86Kr beams from the TAMU Cyclotron to induce α-capture reactions on a ^12C target and produce the unstable isotopes of interest, ^82,90Sr. A new beam line, consisting of a target chamber, target cooling device, and external magnetic field, is being assembled at Rutgers. The ^12C target was evaporated on a substrate of gadolinium backed by a copper foil. A PIPS Si detector will detect α-particles exiting the target after the ^8Be breakup, and γ-rays will be detected by four Ge clover detectors. A digital data acquisition system will record α-γ coincidences. The angular correlation of the emitted γ-rays with respect to the beam direction will be determined from appropriate combinations of γ-ray intensities observed in various elements of the clover detectors. The measurement of the precession angles of the 2^+1 magnetic moments yield the experimental g-factors. The results will be compared to shell model calculations based on ^88Sr as a core nucleus.

  20. Measurements of the spin-orbit interaction and Landé g factor in a pure-phase InAs nanowire double quantum dot in the Pauli spin-blockade regime

    NASA Astrophysics Data System (ADS)

    Wang, Jiyin; Huang, Shaoyun; Lei, Zijin; Pan, Dong; Zhao, Jianhua; Xu, H. Q.

    2016-08-01

    We demonstrate direct measurements of the spin-orbit interaction and Landé g factors in a semiconductor nanowire double quantum dot. The device is made from a single-crystal pure-phase InAs nanowire on top of an array of finger gates on a Si/SiO2 substrate and the measurements are performed in the Pauli spin-blockade regime. It is found that the double quantum dot exhibits a large singlet-triplet energy splitting of ΔST ˜ 2.3 meV, a strong spin-orbit interaction of ΔSO ˜ 140 μeV, and a large and strongly level-dependent Landé g factor of ˜12.5. These results imply that single-crystal pure-phase InAs nanowires are desired semiconductor nanostructures for applications in quantum information technologies.

  1. Theory of Bound-Electron g Factor in Highly Charged Ions

    SciTech Connect

    Shabaev, V. M.; Glazov, D. A.; Plunien, G.; Volotka, A. V.

    2015-09-15

    The paper presents the current status of the theory of bound-electron g factor in highly charged ions. The calculations of the relativistic, quantum electrodynamics (QED), nuclear recoil, nuclear structure, and interelectronic-interaction corrections to the g factor are reviewed. Special attention is paid to tests of QED effects at strong coupling regime and determinations of the fundamental constants.

  2. Giant g-factors of natural impurities in synthetic quartz

    SciTech Connect

    Goryachev, Maxim; Farr, Warrick G.; Tobar, Michael E.

    2013-12-23

    We report the observation of g-factors of natural paramagnetic impurities in a pure synthetic quartz crystal at milli-Kelvin temperatures. Measurements are made by performing spectroscopy using multiple high-Q whispering gallery modes sustained in the crystal. Extreme sensitivity of the method at low temperatures allows the determination of natural residual impurities introduced during the crystal growth. We observe g-factors that significantly differ from integer multiples of the electron g-factor in vacuum, and with values of up to 7.6, which reveals much stronger coupling between impurities and the crystal lattice than in previous studies. Both substitutional and interstitial ions are proposed as candidates for the observed interactions.

  3. Magnetic Frustration from Nonuniform g-factors

    NASA Astrophysics Data System (ADS)

    Yin, Weiguo

    Frustrated magnets are commonly known as materials in which localized magnetic moments, or spins, interact through competing exchange interactions that cannot be simultaneously satisfied. Here we show that even when the exchange interactions are fully cooperative, magnetic frustration can be induced by nonuniform Landé g factors, leading to a mutual interplay of typical ferromagnetic (FM) and antiferromagnetic (AF) features. This novel physics--exactly demonstrated in the one-dimensional Ising model with alternating g factors--provides new insight into the puzzling phenomenon that the magnetic susceptibility of many AF or FM materials is FM-like at low temperature but AF-like at high temperature. Furthermore, we found a unique magnetic-field-driven quantum critical point at which one half of the spins are frozen into a complete order and the other half are fully disordered. The present theory joins the recent intensive search for frustrated magnets beyond the ``standard model'' of condensed matter physics. It could broaden our understanding and design of exotic magnetic behaviors such as spin ice, spin glass, and spin liquid that are essential to quantum computing, spintronics, and high-temperature superconductivity Work supported by U.S. Department of Energy, Office of Basic Energy Science, under Contract No. DE-AC02-98CH10886.

  4. g factor of the first 2+ state in 164Yb

    SciTech Connect

    Z. Berant; A. Wolf et al.

    2004-03-17

    The g factor of the first excited 2+ state of 164Yb was measured by perturbed gamma-gamma angular correlation in an external static magnetic field of 5.55T. The result g(2+)=0.32(5), extends the systematics for Yb isotopes down to N=94. The behavior of known experimental values of g(2+) vs N for all isotopic chains Ba to Pt is discussed.

  5. Particle-rotor versus particle-vibration features in g factors of 111Cd and 113Cd

    NASA Astrophysics Data System (ADS)

    Stuchbery, A. E.; Chamoli, S. K.; Kibédi, T.

    2016-03-01

    The emergence and evolution of collective excitations in complex nuclei remains a central problem in the quest to understand the nuclear many-body problem. Nuclear quadrupole collectivity is usually investigated via electric quadrupole observables. Here, however, we measure the g factors of low-excitation states in 111Cd and 113Cd and show that they are sensitive to the nature of the collectivity in these nuclei in ways that the electric quadrupole observables are not. The particle-vibration model, which assumes spherical core excitations, cannot explain the g factors, whereas a particle-rotor model with a small, nonzero core deformation does. The contrast of the two models is made stark by the fact that they begin from the same limiting g -factor values: It is shown that when an odd nucleon occupies a spherical orbit with angular momentum j =1 /2 , or a deformed orbit with j =1 /2 parentage, the particle-vibration model and the particle-rotor model both reduce to the same g -factor value in their respective limits of zero particle-vibration coupling or zero deformation.

  6. Fresh nuclear fuel measurements at Ukrainian nuclear power plants

    SciTech Connect

    Kuzminski, Jozef; Ewing, Tom; Dickman, Debbie; Gavrilyuk, Victor; Drapey, Sergey; Kirischuk, Vladimir; Strilchuk, Nikolay

    2009-01-01

    In 2005, the Provisions on Nuclear Material Measurement System was enacted in Ukraine as an important regulatory driver to support international obligations in nuclear safeguards and nonproliferation. It defines key provisions and requirements for material measurement and measurement control programs to ensure the quality and reliability of measurement data within the framework of the State MC&A System. Implementing the Provisions requires establishing a number of measurement techniques for both fresh and spent nuclear fuel for various types of Ukrainian reactors. Our first efforts focused on measurements of fresh nuclear fuel from a WWR-1000 power reactor.

  7. Average g-Factors of Anisotropic Polycrystalline Samples

    SciTech Connect

    Fishman, Randy Scott; Miller, Joel S.

    2010-01-01

    Due to the lack of suitable single crystals, the average g-factor of anisotropic polycrystalline samples are commonly estimated from either the Curie-Weiss susceptibility or the saturation magnetization. We show that the average g-factor obtained from the Curie constant is always greater than or equal to the average g-factor obtained from the saturation magnetization. The average g-factors are equal only for a single crystal or an isotropic polycrystal. We review experimental results for several compounds containing the anisotropic cation [Fe(C5Me5)2]+ and propose an experiment to test this inequality using a compound with a spinless anion.

  8. Precision comparison of the g-factor of the proton and anti-proton

    NASA Astrophysics Data System (ADS)

    Disciacca, Jack

    2013-05-01

    We report the first measurement of the antiproton magnetic moment using a single antiproton. The magnetic moment in nuclear magnetons is μp /μN = - 2 . 792845 +/- 0 . 000012 , a 4.4 parts per million (ppm) measurement. This represents a factor of 680 improvement in precision over previous work using exotic atom spectroscopy, which has achieved a 3000 ppm precision and remained essentially unchanged in the past 20 years., Our measurement allows for an improved comparison of the proton and antiproton magnetic moments, yielding a result consistent with the prediction of charge, parity and time reversal symmetry. Following a proof of principle, 2.5 ppm measurement of the proton magnetic moment, the experiment was moved to CERN for the antiproton experiment. Initial work focused on catching, cooling and trapping a single antiproton from the 5 MeV beam at CERN's Antiproton Decelerator. Following this work, we undertook a magnetic moment measurement. The spin and cyclotron frequency are measured to determine the g-factor, g / 2 =fs /fc . Prospects for further improvement should be possible with single spin flip detection, similar to what was used to measure the electron magnetic moment - currently the most precisely measured property of a fundamental particle. The new antiproton magnetic moment measurement is likely a first step towards improved precision by an additional factor of 103 or 104 improvement, with a precision at the part per billion level.,, A. Kreissl, et al., Z. Phys. C: Part. Fields 37, 557 (1988).

  9. g factor of the 2{sub 1}{sup +} state of {sup 172}Hf

    SciTech Connect

    Berant, Z.; Wolf, A.; Oster, E.; Casperson, R. J.; Werner, V.; Heinz, A.; Casten, R. F.; Terry, J. R.; Winkler, R.; Williams, E.; Qian, J.; Schmidt, A.; Smith, M. K.; Ahn, T.; Gurdal, G.; McCutchan, E. A.; Brenner, D. S.; Beausang, C. W.; Regan, P. H.; Ross, T.

    2009-11-15

    The g factor of the 2{sub 1}{sup +} state of {sup 172}Hf was measured using the perturbed angular correlation technique in a static external magnetic field. The result, g(2{sub 1}{sup +})=0.25(5), is discussed in relation to the systematics of the previously reported g factors in the Hf isotopes and compared with the predictions of several models. An interesting outcome of the analysis presented in this paper is the agreement between the calculated g factors within the interacting boson approximation (IBA) and the results of a large-scale shell model calculation. This agreement supports the emphasis in the IBA on the valence space. The undershooting of the empirical g factors near midshell in both models suggests that they underestimate the role of the saturation of collectivity, which is explicitly incorporated into a phenomenological model that agrees better with the data.

  10. g-factor of the 2{sup+}{sub{1} state of {sup179}Hf.

    SciTech Connect

    Berant, Z.; Oster, E.; Wolf, A.; Casperson, R. J.; Werner, V.; McCutchan, E. A.

    2009-01-01

    The g factor of the 2{sub 1}{sup +} state of {sup 172}Hf was measured using the perturbed angular correlation technique in a static external magnetic field. The result, g(2{sub 1}{sup +}) = 0.25(5), is discussed in relation to the systematics of the previously reported g factors in the Hf isotopes and compared with the predictions of several models. An interesting outcome of the analysis presented in this paper is the agreement between the calculated g factors within the interacting boson approximation (IBA) and the results of a large-scale shell model calculation. This agreement supports the emphasis in the IBA on the valence space. The undershooting of the empirical g factors near midshell in both models suggests that they underestimate the role of the saturation of collectivity, which is explicitly incorporated into a phenomenological model that agrees better with the data.

  11. InAs 2DEGs:What's the g-factor?

    NASA Astrophysics Data System (ADS)

    McCombe, B. D.; Pakmehr, Mehdi; Khaetskii, A.; Chiatti, Olivio; Fischer, S. F.; Buchholz, S.; Heyn, C.; Hansen, W.; Cahay, M.; Newrock, R. S.; Bandari, Nikhil

    2014-03-01

    Interest in spin-orbit effects in semiconductors has led us to study the electron g-factor in quasi-2DEG InAs samples. We have made magneto-transport and -photoresponse (PR) measurements on InAs QW structures in magnetic fields up to 10 T. THz cyclotron resonance (CR) is manifested in PR as a resonant envelope of the amplitude of quantum oscillations, which show clear spin-splitting (for lower mobility samples) down 4T, while direct R_xx measurements show no spin-splitting up to 9T. R_xx oscillations in a higher mobility sample show well-resolved spin-splittings over a range of fields as does the PR. We have simulated the data with a theoretical expression for 2DEG SdH oscillations (coupled with CR resonant carrier heating for the PR) and extracted g-factors from fits. We also used a different (commonly used) method, SdH oscillations vs. tilt angle of the field to extract g-factors from the angle at which the SdH frequency doubles. We find very large g-factors from fits to R_xx and PR (14 - 20), but g-factors 2-3 times smaller for these same samples from tilted field experiments (close to estimated band g-factors). These results are discussed in terms of exchange effects. Support: NSF DMR 1008138 (Buffalo); NSF ECCE 1028483(Cincinnati); DFG Fi932/4-1(Berlin).

  12. The g-factor of the K = 25 isomer in /sup 182/Os

    SciTech Connect

    Alderson, A.; Broude, C.; Bruce, A.; Dafni, E.; Fallon, P.; Goldring, G.; Hass, M; Nyberg, J.; Roberts, J.; Sharpey-Schafer, J.; Sletten, G.; Twin, P.

    1988-01-01

    The g-factor of the K = I = 25, 120 ns isomer in /sup 182/Os has been measured by observing the angular precession of the decay /gamma/-rays in an external magnetic field. Our preliminary result is g = 0.46(5). Comparing this result to predictions based on experimental g-factors of single-particle Nilsson orbitals in this mass region suggests equal contributions of neutron and proton spin to the total spin of I = 25. An attempt has also been undertaken to measure the quadrupole moment of this level by observing the time-dependent quadrupole interaction pattern of Os nuclei recoiling into an Os single crystal. The analysis of the quadrupole moment measurement, as well as a more detailed analysis of the g-factor measurement, is now in progress. 7 refs., 2 figs.

  13. Nuclear symmetry energy at subnormal densities from measured nuclear masses

    SciTech Connect

    Liu Min; Wang Ning; Li Zhuxia; Zhang Fengshou

    2010-12-15

    The symmetry energy coefficients for nuclei with mass number A=20-250 are extracted from more than 2000 measured nuclear masses. With the semiempirical connection between the symmetry energy coefficients of finite nuclei and the nuclear symmetry energy at reference densities, we investigate the density dependence of the symmetry energy of nuclear matter at subnormal densities. The obtained results are compared with those extracted from other methods.

  14. Determination of g-factor in a quantum well channel with a strong Rashba effect

    SciTech Connect

    Choi, Won Young; Cheol Koo, Hyun; Chang, Joonyeon; Hoon Lee, Jung

    2014-05-07

    Using the Shubnikov−de Haas oscillation measurement, the g-factor of carriers in a strong Rashba system is observed. To determine g-factor of carriers in the InAs quantum well channel with a strong Rashba effect, the magnetic fields are simultaneously applied along the in-plane direction and the perpendicular direction. The perpendicular field drives the oscillation of conductance for measuring Rashba spin orbit interaction and the in-plane field parallel to the Rashba field interacts with Rashba effect and modifies the intrinsic Rashba parameter. The total field inside the channel is a combination of the Rashba field and the in-plane field, so the modification of Rashba parameter gives a g-factor value of ∼13 in our system.

  15. Measurement control administration for nuclear materials accountability

    SciTech Connect

    Rudy, C.R.

    1991-01-31

    In 1986 a measurement control program was instituted at Mound to ensure that measurement performance used for nuclear material accountability was properly monitored and documented. The organization and management of various aspects of the program are discussed. Accurate measurements are the basis of nuclear material accountability. The validity of the accountability values depends on the measurement results that are used to determine inventories, receipts, and shipments. With this measurement information, material balances are calculated to determine losses and gains of materials during a specific time period. Calculation of Inventory Differences (ID) are based on chemical or physical measurements of many items. The validity of each term is dependent on the component measurements. Thus, in Figure 1, the measured element weight of 17 g is dependent on the performance of the particular measurement system that was used. In this case, the measurement is performed using a passive gamma ray method with a calibration curve determined by measuring representative standards containing a range of special nuclear materials (Figure 2). One objective of a measurement control program is to monitor and verify the validity of the calibration curve (Figure 3). In 1986 Mound's Nuclear Materials Accountability (NMA) group instituted a formal measurement control program to ensure the validity of the numbers that comprise this equation and provide a measure of how well bulk materials can be controlled. Most measurements used for accountability are production measurements with their own quality assurance programs. In many cases a measurement control system is planned and maintained by the developers and operators of the particular measurement system with oversight by the management responsible for the results. 4 refs., 7 figs.

  16. Influence of ion movement in a particle trap on the bound electron g factor

    NASA Astrophysics Data System (ADS)

    Michel, Niklas; Zatorski, Jacek; Keitel, Christoph H.

    2015-11-01

    In the relativistic description of atomic systems in external fields, the total momentum and the external electric field couple to the angular momentum of the individual particles. Therefore, the motional state of an ion in a particle trap influences measurements of internal observables such as energy levels or the g factor. We calculate the resulting relativistic shift of the Larmor frequency and the corresponding g -factor correction for a bound electron in a hydrogenlike ion in the 1 S state due to the ion moving in a Penning trap and show that it is negligible at the current precision of measurements. We also show that the analogous energy shift for measurements with an ion in the ground state of a Paul trap vanishes in leading order.

  17. Superconducting quantum spin Hall systems with giant orbital g factors

    NASA Astrophysics Data System (ADS)

    Reinthaler, R. W.; Tkachov, G.; Hankiewicz, E. M.

    2015-10-01

    Topological aspects of superconductivity in quantum spin Hall systems (QSHSs) such as thin layers of three-dimensional topological insulators (TIs) or two-dimensional TIs are the focus of current research. Here, we describe a superconducting quantum spin Hall effect (quantum spin Hall system in proximity to an s -wave superconductor and in orbital in-plane magnetic fields), which is protected against elastic backscattering by combined time-reversal and particle-hole symmetry. This effect is characterized by spin-polarized edge states, which can be manipulated in weak magnetic fields due to a giant effective orbital g factor, allowing the generation of spin currents. The phenomenon provides a solution to the outstanding challenge of detecting the spin polarization of the edge states. Here we propose the detection of the edge polarization in a three-terminal junction using unusual transport properties of the superconducting quantum Hall effect: a nonmonotonic excess current and a zero-bias conductance peak splitting.

  18. Holdup measurement for nuclear fuel manufacturing plants

    SciTech Connect

    Zucker, M.S.; Degen, M.; Cohen, I.; Gody, A.; Summers, R.; Bisset, P.; Shaub, E.; Holody, D.

    1981-07-13

    The assay of nuclear material holdup in fuel manufacturing plants is a laborious but often necessary part of completing the material balance. A range of instruments, standards, and a methodology for assaying holdup has been developed. The objectives of holdup measurement are ascertaining the amount, distribution, and how firmly fixed the SNM is. The purposes are reconciliation of material unbalance during or after a manufacturing campaign or plant decommissioning, to decide security requirements, or whether further recovery efforts are justified.

  19. Antineutrinos from nuclear reactors: recent oscillation measurements

    NASA Astrophysics Data System (ADS)

    Dwyer, D. A.

    2015-02-01

    Nuclear reactors are the most intense man-made source of antineutrinos, providing a useful tool for the study of these particles. Oscillation due to the neutrino mixing angle {{θ }13} is revealed by the disappearance of reactor {{\\bar{ν }}e} over ˜km distances. Use of additional identical detectors located near nuclear reactors reduce systematic uncertainties related to reactor {{\\bar{ν }}e} emission and detector efficiency, significantly improving the sensitivity of oscillation measurements. The Double Chooz, RENO, and Daya Bay experiments set out in search of {{θ }13} using these techniques. All three experiments have recently observed reactor {{\\bar{ν }}e} disappearance, and have estimated values for {{θ }13} of 9.3◦ ± 2.1°, 9.2◦ ± 0.9°, and 8.7◦ ± 0.4° respectively. The energy-dependence of {{\\bar{ν }}e} disappearance has also allowed measurement of the effective neutrino mass difference, \\mid Δ mee2\\mid ≈ \\mid Δ m312\\mid . Comparison with \\mid Δ mμ μ 2\\mid ≈ \\mid Δ m322\\mid from accelerator {{ν }μ } measurements supports the three-flavor model of neutrino oscillation. The current generation of reactor {{\\bar{ν }}e} experiments are expected to reach ˜3% precision in both {{θ }13} and \\mid Δ mee2\\mid . Precise knowledge of these parameters aids interpretation of planned {{ν }μ } measurements, and allows future experiments to probe the neutrino mass hierarchy and possible CP-violation in neutrino oscillation. Absolute measurements of the energy spectra of {{\\bar{ν }}e} deviate from existing models of reactor emission, particularly in the range of 5-7 MeV.

  20. Neutron capture measurements for nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Reifarth, Rene

    2005-04-01

    Almost all of the heavy elements are produced via neutron capture reactions in a multitude of stellar production sites. The predictive power of the underlying stellar models is currently limited because they contain poorly constrained physics components such as convection, rotation or magnetic fields. Neutron captures measurements on heavy radioactive isotopes provide a unique opportunity to largely improve these physics components, and thereby address important questions of nuclear astrophysics. Such species are branch-points in the otherwise uniquely defined path of subsequent n-captures along the s-process path in the valley of stability. These branch points reveal themselves through unmistakable signatures recovered from pre-solar meteoritic grains that originate in individual element producing stars. Measurements on radioactive isotopes for neutron energies in the keV region represent a stringent challenge for further improvements of experimental techniques. This holds true for the neutron sources, the detection systems and the technology to handle radioactive material. Though the activation method or accelerator mass spectroscopy of the reaction products could be applied in a limited number of cases, Experimental facilities like DANCE at LANL, USA and n-TOF at CERN, Switzerland are addressing the need for such measurements on the basis of the more universal method of detecting the prompt capture gamma-rays, which is required for the application of neutron time-of-flight (TOF) techniques. With a strongly optimized neutron facility at the Rare Isotope Accelerator (RIA) isotopes with half-lives down to tens of days could be investigated, while present facilities require half-lives of a few hundred days. Recent neutron capture experiments on radioactive isotopes with relevance for nuclear astrophysics and possibilities for future experimental setups will be discussed during the talk.

  1. Electron g-factor anisotropy in GaAs/Al1-xGaxAs quantum wells of different symmetry

    NASA Astrophysics Data System (ADS)

    Nefyodov, Yu. A.; Shchepetilnikov, A. V.; Kukushkin, I. V.; Dietsche, W.; Schmult, S.

    2011-12-01

    The anisotropy of the electron g factor is investigated in symmetrically (SQW) and asymmetrically (AQW) doped 20-nm GaAs/AlGaAs quantum wells, grown in the [001] direction. Applied was the electrically detected electron spin resonance technique. The AQW demonstrates strong twofold in-plane g-factor anisotropy with the [110] and [11¯0] principal axes. This can be readily ascribed to the internal electric field asymmetry as caused by single-side doping. The SQW is shown to have 10 times as weak (but still detectable) anisotropy with the same principal axes. The linear (in the magnetic field) corrections to the g factor were also carefully measured. The â tensor of these corrections is shown to have at least three different nonzero components, namely, azzz, axxz, and ayyz.

  2. Geochemical Controls on Nuclear Magnetic Resonance Measurements

    SciTech Connect

    Knight, Rosemary; Prasad, Manika; Keating, Kristina

    2003-11-11

    OAK-B135 Our research objectives are to determine, through an extensive set of laboratory experiments, the effect of the specific mineralogic form of iron and the effect of the distribution of iron on proton nuclear magnetic resonance (NMR) relaxation mechanisms. In the first nine months of this project, we have refined the experimental procedures to be used in the acquisition of the laboratory NMR data; have ordered, and conducted preliminary measurements on, the sand samples to be used in the experimental work; and have revised and completed the theoretical model to use in this project. Over the next year, our focus will be on completing the first phase of the experimental work where the form and distribution of the iron in the sands in varied.

  3. An experiment for the direct determination of the g-factor of a single proton in a Penning trap

    NASA Astrophysics Data System (ADS)

    Rodegheri, C. C.; Blaum, K.; Kracke, H.; Kreim, S.; Mooser, A.; Quint, W.; Ulmer, S.; Walz, J.

    2012-06-01

    A new apparatus has been designed that aims at a direct precision measurement of the g-factor of a single isolated proton or antiproton in a Penning trap. We present a thorough discussion on the trap design and a method for the experimental trap optimization using a single stored proton. A first attempt at the g-factor determination has been made in a section of the trap with a magnetic bottle. The Larmor frequency of the proton has been measured with a relative uncertainty of 1.8 × 10-6 and the magnetic moment has been determined with a relative uncertainty of 8.9 × 10-6. A g-factor of 5.585 696(50) has been obtained, which is in excellent agreement with previous measurements and predictions. Future experiments shall drive the spin-flip transition in a section of the trap with a homogeneous magnetic field. This has the potential to improve the precision of the measured g-factor of the proton and the antiproton by several orders of magnitude.

  4. Weighted difference of g factors of light Li-like and H-like ions for an improved determination of the fine-structure constant

    NASA Astrophysics Data System (ADS)

    Yerokhin, V. A.; Berseneva, E.; Harman, Z.; Tupitsyn, I. I.; Keitel, C. H.

    2016-08-01

    A weighted difference of the g factors of the Li- and H-like ion of the same element is studied and optimized in order to maximize the cancelation of nuclear effects. To this end, a detailed theoretical investigation is performed for the finite nuclear size correction to the one-electron g factor, the one- and two-photon exchange effects, and the QED effects. The coefficients of the Z α expansion of these corrections are determined, which allows us to set up the optimal definition of the weighted difference. It is demonstrated that, for moderately light elements, such weighted difference is nearly free from uncertainties associated with nuclear effects and can be utilized to extract the fine-structure constant from bound-electron g -factor experiments with an accuracy competitive with or better than its current literature value.

  5. The Measurement of Nuclear War Attitudes: Methods and Concerns.

    ERIC Educational Resources Information Center

    Mayton, Daniel M., II

    Measures of adults' attitudes toward nuclear war are briefly discussed, and Mayton's Modified World Affairs Questionnaire (MWAQ) is described. The 23-item MWAQ was developed from Novak and Lerner's World Affairs Questionnaire, a nuclear war attitude measure by Mayton and Delamater, and related interview items by Jeffries. When the MWAQ was…

  6. Large anisotropy of electron and hole g factors in infrared-emitting InAs/InAlGaAs self-assembled quantum dots

    NASA Astrophysics Data System (ADS)

    Belykh, V. V.; Yakovlev, D. R.; Schindler, J. J.; Zhukov, E. A.; Semina, M. A.; Yacob, M.; Reithmaier, J. P.; Benyoucef, M.; Bayer, M.

    2016-03-01

    A detailed study of the g -factor anisotropy of electrons and holes in InAs/In0.53Al0.24Ga0.23As self-assembled quantum dots emitting in the telecom spectral range of 1.5 -1.6 μ m (around 0.8 eV photon energy) is performed by time-resolved pump-probe ellipticity technique using a superconducting vector magnet. All components of the g -factor tensors are measured, including their spread in the quantum dot (QD) ensemble. Surprisingly, the electron g factor shows a large anisotropy changing from ge ,x=-1.63 to ge ,z=-2.52 between directions perpendicular and parallel to the dot growth axis, respectively, at an energy of 0.82 eV. The hole g -factor anisotropy at this energy is even stronger: | gh,x|=0.64 and | gh,z|=2.29 . On the other hand, the in-plane anisotropies of electron and hole g factors are small. The pronounced out-of-plane anisotropy is also observed for the spread of the g factors, determined from the spin dephasing time. The hole longitudinal g factors are described with a theoretical model that allows us to estimate the QD parameters. We find that the QD height-to-diameter ratio increases while the indium composition decreases with increasing QD emission energy.

  7. The electron g factor in AlGaN/GaN quantum wells

    NASA Astrophysics Data System (ADS)

    Li, Ming; Feng, Zhi-Bo.; Fan, Libo; Zhao, Yilong; Han, Hongpei; Feng, Tuanhui

    2016-04-01

    Considering the Rashba and Zeeman effects, the effective Hamiltonian for electrons in AlGaN/GaN quantum wells (QWs) with the magnetic field is obtained, and the effective transverse and longitudinal g-factor (g⊥,//), are derived. The small anisotropy of the g factor in bulk wurtzite materials is clearly shown, while the anisotropy in QWs induced by the quantum confined effect is evident. Moreover, the average g factor (g*) depends greatly on the position of the origin along the growth axis (c axis). With increasing well thickness, both g⊥ and g// increase, and the g-factor anisotropy first decreases and then increases slowly. Results show the g-factor and its anisotropy in III-nitride QWs can be modulated by the well thickness, and they are greatly affected by the internal electric field and the quantum confined effect.

  8. Mapping the anisotropic Lande g-factor tensor of 1D GaAs holes in all 3 spatial directions

    NASA Astrophysics Data System (ADS)

    Hudson, Karina; Srinivasan, Ashwin; Wang, Qingwen; Yeoh, Lareine; Klochan, Oleh; Farrer, Ian; Ritchie, David; Hamilton, Alex

    2014-03-01

    We have studied the Zeeman splitting of 1D holes formed on a (100) GaAs/AlGaAs heterostructure on a single cooldown. The strong spin orbit coupling and 1D confinment give rise to a highly anisotropic spin splitting. By use of the high-symmetry (100) crystal, we eliminate the effects of crystal anisotropy on our measurements. In measuring the spin splitting as a function of angle between the wire and the applied magnetic field, we are able to identify the principle axes of the g-tensor. We show that the principle axes are defined by the potential confining the 1D holes, and are not affected by the crystal axes. We find that g∥⊥ g-factors parallel and perpendicular to the wire, and g⊥ refers to the g-factor perpendicular to the 2D well.

  9. Fifty years of nuclear fission: Nuclear data and measurements series

    SciTech Connect

    Lynn, J.E.

    1989-06-01

    This report is the written version of a colloquium first presented at Argonne National Laboratory in January 1989. The paper begins with an historical preamble about the events leading to the discovery of nuclear fission. This leads naturally to an account of early results and understanding of the fission phenomena. Some of the key concepts in the development of fission theory are then discussed. The main theme of this discussion is the topography of the fission barrier, in which the interplay of the liquid-drop model and nucleon shell effects lead to a wide range of fascinating phenomena encompassing metastable isomers, intermediate-structure effects in fission cross-sections, and large changes in fission product properties. It is shown how study of these changing effects and theoretical calculations of the potential energy of the deformed nucleus have led to broad qualitative understanding of the nature of the fission process. 54 refs., 35 figs.

  10. g-factor anisotropy in nanowire-based InAs quantum dots

    SciTech Connect

    D'Hollosy, Samuel; Fábián, Gábor; Baumgartner, Andreas; Schönenberger, Christian; Nygård, Jesper

    2013-12-04

    The determination and control of the electron g-factor in semiconductor quantum dots (QDs) are fundamental prerequisites in modern concepts of spintronics and spin-based quantum computation. We study the dependence of the g-factor on the orientation of an external magnetic field in quantum dots (QDs) formed between two metallic contacts on stacking fault free InAs nanowires. We extract the g-factor from the splitting of Kondo resonances and find that it varies continuously in the range between |g*| = 5 and 15.

  11. Electrical control of the sign of the g factor in a GaAs hole quantum point contact

    NASA Astrophysics Data System (ADS)

    Srinivasan, A.; Hudson, K. L.; Miserev, D.; Yeoh, L. A.; Klochan, O.; Muraki, K.; Hirayama, Y.; Sushkov, O. P.; Hamilton, A. R.

    2016-07-01

    Zeeman splitting of one-dimensional hole subbands is investigated in quantum point contacts fabricated on a (311)-oriented GaAs-AlGaAs heterostructure. Transport measurements can determine the magnitude of the g factor, but cannot usually determine the sign. Here we use a combination of tilted fields and a unique off-diagonal element in the hole g tensor to directly detect the sign of g*. We are able to tune not only the magnitude, but also the sign of the g factor by electrical means, which is of interest for spintronics applications. Furthermore, we show theoretically that the resulting behavior of g* can be explained by the momentum dependence of the spin-orbit interaction.

  12. g Factor of the 7- isomer in 126Sn and first observation of spin-alignment in relativistic fission

    NASA Astrophysics Data System (ADS)

    Ilie, G.; Neyens, G.; Simpson, G. S.; Jolie, J.; Blazhev, A.; Grawe, H.; Lozeva, R. L.; Vermeulen, N.; Atanasova, L.; Balabanski, D. L.; Becker, F.; Bednarczyk, P.; Brandau, C.; Caceres, L.; Chamoli, S. K.; Daugas, J. M.; Doornenbal, P.; Gerl, J.; Górska, M.; Grȩbosz, J.; Hass, M.; Ionescu-Bujor, M.; Jungclaus, A.; Kmiecik, M.; Kojouharov, I.; Kurz, N.; Maj, A.; Mallion, S.; Perru, O.; Pfützner, M.; Podolyák, Zs.; Prokopowicz, W.; De Rydt, M.; Saito, T. R.; Schaffner, H.; Turzó, K.; Walker, J.; Werner-Malento, E.; Wollersheim, H. J.

    2010-04-01

    We report on the g factor measurement of the isomeric 7 state (E=2219 keV, T1/2=5.9(8) μs) in the neutron-rich 126Sn nucleus. The nucleus was produced by the fission of a relativistic 238U beam and reaction products were selected by the FRS fragment separator at GSI. For the first time, spin-alignment was observed after relativistic fission. It was used to deduce the g factor of the 7 isomeric state, g(7)=-0.098(9), from the measured perturbed angular distribution of its γ decay using the RISING Cluster detectors. The observed value confirms the suggested ν(h11/2-1d3/2-1) dominant configuration, which has been proposed for the 7 isomers in neutron-rich Sn isotopes. The failure of the g factor additivity rule and the importance of core polarization evolution with increasing distance from the doubly-magic 132Sn is discussed. The first observation of 18(8)% of spin-alignment produced by the relativistic fission of a 238U beam paves the way to study moments of neutron-rich (sub-)microsecond isomers, which are difficult to align by other means.

  13. Measuring Neutrino Oscillations with Nuclear Reactors

    SciTech Connect

    McKeown, R. D.

    2007-10-26

    Since the first direct observations of antineutrino events by Reines and Cowan in the 1950's, nuclear reactors have been an important tool in the study of neutrino properties. More recently, the study of neutrino oscillations has been a very active area of research. The pioneering observation of oscillations by the KamLAND experiment has provided crucial information on the neutrino mixing matrix. New experiments to study the remaining unknown mixing angle are currently under development. These recent studies and potential future developments will be discussed.

  14. Hadronization measurements in cold nuclear matter

    SciTech Connect

    Dupre, Raphael

    2015-05-01

    Hadronization is the non-perturbative process of QCD by which partons become hadrons. It has been studied at high energies through various processes, we focus here on the experiments of lepto-production of hadrons in cold nuclear matter. By studying the dependence of observables to the atomic number of the target, these experimentscan give information on the dynamic of the hadronization at the femtometer scale. In particular, we will present preliminary results from JLab Hall B (CLAS collaboration), which give unprecedented statistical precision. Then, we will present results of a phenomenological study showing how HERMES data can be described with pure energyloss models.

  15. Assays to measure nuclear mechanics in interphase cells

    PubMed Central

    Isermann, Philipp; Davidson, Patricia M.; Sliz, Josiah D.

    2012-01-01

    The nucleus is the characteristic hallmark of all eukaryotic cells. The physical properties of the nucleus reflect important biological characteristics, such as chromatin organization or nuclear envelope composition; they can also directly affect cellular function, for example, when cells pass through narrow constrictions, where the stiff nucleus may present a limiting factor. We present two complementary techniques to probe the mechanical properties of the nucleus. In the first, nuclear stiffness relative to the surrounding cytoskeleton is inferred from induced nuclear deformations during strain application to cells on an elastic substrate. In the second approach, nuclear deformability is deduced from the transit time through a perfusion-based microfabricated device with constrictions smaller than the size of the nucleus. These complementary methods, which can be applied to measure nuclear stiffness in large numbers of living adherent or suspended cells, can help identify important changes in nuclear mechanics associated with disease or development. PMID:22968843

  16. Slotted surface coil with reduced g-factor for SENSE imaging.

    PubMed

    Ocegueda, K; Rodriguez, A O

    2006-01-01

    A new coil design inspired on the slot-and-hole magnetron tube is proposed for SENSE imaging. To investigate its g-factor behaviour: an SNR formula was derived using the quasi-static approach, and combined with the ultimate g-factor formula to compute the ultimate-factor-g-vs-depth plots. A g-factor expression was derived for the circular coil using the same approach for comparison purposes. SNR-vs-depth profiles of an 4-slot coil showed an important improvement over the circular coil. The 4-slot coil g-factor can be up to 58.32% lower than that of a single circular-shaped coil. This improvement makes the slotted surface coil a good choice for SENSE imaging. PMID:17946922

  17. G-factors of hole bound states in spherically symmetric potentials in cubic semiconductors

    NASA Astrophysics Data System (ADS)

    Miserev, Dmitry; Sushkov, Oleg

    2016-03-01

    Holes in cubic semiconductors have effective spin 3/2 and very strong spin orbit interaction. Due to these factors properties of hole bound states are highly unusual. We consider a single hole bound by a spherically symmetric potential, this can be an acceptor or a spherically symmetric quantum dot. Linear response to an external magnetic field is characterized by the bound state Lande g-factor. We calculate analytically g-factors of all bound states.

  18. Revealing the Atomic Site-Dependent g Factor within a Single Magnetic Molecule via the Extended Kondo Effect

    NASA Astrophysics Data System (ADS)

    Du, Shixuan

    Control over charge and spin states at the single molecule level is crucial not only for a fundamental understanding of charge and spin interactions but also represents a prerequisite for development of molecular electronics and spintronics. In this talk, I will talk about the extended spin distribution in space beyond the central Mn ion, and onto the non-magnetic constituent atoms of the MnPc molecule. This extended spin distribution results in an extended Kondo effect, which can be explained by spin polarization induced by symmetry breaking of the molecular framework, as confirmed by DFT calculations. Measuring the evolution of the Kondo splitting with applied magnetic fields at different atomic sites, we find a spatial variation of the g-factor within a single molecule for the first time. The existence of atomic site-dependent g-factors can be attributed to specific molecular orbitals distributed over the entire molecule. This work not only open up a new opportunity for quantum information recording, but also provide a new route to explore the internal electronic and spin structure of complex molecules, hard to achieve otherwise. (L. W. Liu et al., Phys. Rev. Lett. 2015, 114, 126601. In collaboration with Liwei Liu, Kai Yang, Yuhang Jiang, Li Gao, Qi Liu, Boqun Song, Wende Xiao, Haitao Zhou, Hongjun Gao in CAS, Min Ouyang in MU, and A.H. Castro Neto in SNU.) Revealing the Atomic Site-Dependent g Factor within a Single Magnetic Molecule via the Extended Kondo Effect.

  19. Effective mass and Landé g-factor in Si-MOSFETs near the critical density

    NASA Astrophysics Data System (ADS)

    Limouny, Lhoussine; El Kaaouachi, Abdelhamid; Liang, Chi-Te

    2014-02-01

    We analyze the electrical resistivity and conductivity of a dilute two-dimensional electron gas (2DEG) in a Si metal-oxide-semiconductor field-effect transistor. When a magnetic field is applied parallel to the plane of the 2DEG, a signature of complete spin polarization, as evidenced by the saturation of the resistivity, is observed. We measured the effective mass and the Landé g-factor near the metal-insulator transition (MIT) and found that the Landé g-factor remained almost constant and close to its value in bulk silicon. In contrast, we have observed a sharp increase in the effective mass near the critical density of the MIT. Our new results suggest that the sharp increase in the previously-observed spin susceptibility is mainly due to the enhanced effective mass. Therefore, renormalization of the effective mass could play an important role in a dilute spinpolarized 2DEG. The data indicate that electron-electron interactions strongly modify the effective mass but only weakly affect the g-factor in a dilute 2DEG. Moreover, our results indicate that B c , which corresponds to the magnetic field at which the magnetoresistivity reaches saturation, vanishes at a characteristic density n χ higher than the critical density n c of the MIT. This is in contrast to the existing experimental results, and further studies are required if this discrepancy is to be understood.

  20. Lifetime Measurements of Tagged Exotic- and Unbound Nuclear States

    SciTech Connect

    Cullen, D. M.

    2011-11-30

    A new Differential Plunger device for measuring pico-second lifetimes of Unbound Nuclear States (DPUNS) is being built at The University of Manchester. DPUNS has been designed to work with alpha-, beta- and isomer-tagging methods using the existing JUROGAM II--RITU--GREAT infrastructure at the University of Jyvaskyla, Finland. The importance of proton emission from nuclei is that it provides valuable nuclear-structure information as direct input to nuclear models beyond the drip line. New experimental data beyond the drip line can provide new extensions to these models especially with the possible coupling of weakly bound and unbound states to the continuum. The results of the first experiments to measure lifetimes of unbound nuclear states with this method was discussed along with possible future experiments which can be addressed with DPUNS using proton-, isomer- and alpha-tagging.

  1. Determination of parameters of a nuclear reactor through noise measurements

    DOEpatents

    Cohn, C.E.

    1975-07-15

    A method of measuring parameters of a nuclear reactor by noise measurements is described. Noise signals are developed by the detectors placed in the reactor core. The polarity coincidence between the noise signals is used to develop quantities from which various parameters of the reactor can be calculated. (auth)

  2. A dc amplifier for nuclear particle measurement

    NASA Technical Reports Server (NTRS)

    Macnee, A. B.; Masnari, N. A.

    1978-01-01

    A monolithic preamplifier-postamplifier combination has been developed for use with solid state particle detectors. The direct coupled amplifiers employ interdigitated n-channel JFET's, diodes, and diffused resistors. The circuits developed demonstrate the feasibility of matching the performance of existing discrete component designs. The fabrication procedures for the monolithic amplifier fabrication are presented and the results of measurements on a limited number of sample amplifiers are given.

  3. Measurements of nuclear spin dynamics by spin-noise spectroscopy

    SciTech Connect

    Ryzhov, I. I.; Poltavtsev, S. V.; Kozlov, G. G.; Zapasskii, V. S.; Kavokin, K. V.; Glazov, M. M.; Vladimirova, M.; Scalbert, D.; Cronenberger, S.; Lemaître, A.; Bloch, J.

    2015-06-15

    We exploit the potential of the spin noise spectroscopy (SNS) for studies of nuclear spin dynamics in n-GaAs. The SNS experiments were performed on bulk n-type GaAs layers embedded into a high-finesse microcavity at negative detuning. In our experiments, nuclear spin polarisation initially prepared by optical pumping is monitored in real time via a shift of the peak position in the electron spin noise spectrum. We demonstrate that this shift is a direct measure of the Overhauser field acting on the electron spin. The dynamics of nuclear spin is shown to be strongly dependent on the electron concentration.

  4. First Principles Computation of G-Factors in Bi and Bi2Se3

    NASA Astrophysics Data System (ADS)

    Song, Zhida; Nie, Simin; di, Xi; Fang, Zhong; T03 Team

    In this talk, we propose a first principles computation method for g-factor tensor,which not only gives comparable results with experiments but also establishes a clear physical picture of Zeeman effect in materials. In our method, the Hilbert space of the electronic states is treated as a direct product of ''inner'' space and ''orbital'' space, which are spanned by Bloch wave-functions and envelope functions respectively. Correspondingly, vector-potential is divided into a periodic part acting only in inner space and a non-periodic part acting only in orbital space. With the above flamework we define the g-factors as coupling coefficients between inner space and magnetic field. By the method we developed, we have further computed the g-factors of bismuth and Bi2Se3 and get satisfactory results, which are in good agreement with the experimental data.

  5. Temperature and donor concentration dependence of the conduction electron Lande g-factor in silicon

    NASA Astrophysics Data System (ADS)

    Konakov, Anton A.; Ezhevskii, Alexander A.; Soukhorukov, Andrey V.; Guseinov, Davud V.; Popkov, Sergey A.; Burdov, Vladimir A.

    2013-12-01

    Temperature and donor concentration dependence of the conduction electron g-factor in silicon has been investigated both experimentally and theoretically. We performed electron spin resonance experiments on Si samples doped with different densities of phosphorus and lithium. Theoretical consideration is based on the renormalization of the electron energy in a weak magnetic field by the interaction with possible perturbing agents, such as phonons and impurity centers. In the second-order perturbation theory interaction of the electron subsystem with the lattice vibrations as well as ionized donors results in decreasing the conduction electron g-factor, which becomes almost linear function both of temperature and impurity concentration.

  6. Temperature dependence of the electron Landé g-factor in cubic GaN

    NASA Astrophysics Data System (ADS)

    Buß, J. H.; Schupp, T.; As, D. J.; Hägele, D.; Rudolph, J.

    2015-12-01

    The temperature dependence of the electron Landé g-factor in bulk cubic GaN is investigated over an extremely broad temperature range from 15 K up to 500 K by time-resolved Kerr-rotation spectroscopy. The g-factor is found to be approximately constant over the full investigated temperature range. Calculations by k .p -theory predict a negligible temperature dependence g(T) in complete agreement with the experiment as a consequence of the large band-gap and small spin orbit splitting in cubic GaN.

  7. Recent measurements for hadrontherapy and space radiation: nuclear physics

    NASA Technical Reports Server (NTRS)

    Miller, J.

    2001-01-01

    The particles and energies commonly used for hadron therapy overlap the low end of the charge and energy range of greatest interest for space radiation applications, Z=1-26 and approximately 100-1000 MeV/nucleon. It has been known for some time that the nuclear interactions of the incident ions must be taken into account both in treatment planning and in understanding and addressing the effects of galactic cosmic ray ions on humans in space. Until relatively recently, most of the studies of nuclear fragmentation and transport in matter were driven by the interests of the nuclear physics and later, the hadron therapy communities. However, the experimental and theoretical methods and the accelerator facilities developed for use in heavy ion nuclear physics are directly applicable to radiotherapy and space radiation studies. I will briefly review relevant data taken recently at various accelerators, and discuss the implications of the measurements for radiotherapy, radiobiology and space radiation research.

  8. 78 FR 45573 - Compensatory and Alternative Regulatory Measures for Nuclear Power Plant Fire Protection (CARMEN...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-29

    ... COMMISSION Compensatory and Alternative Regulatory Measures for Nuclear Power Plant Fire Protection (CARMEN-FIRE) AGENCY: Nuclear Regulatory Commission. ACTION: Notice of availability; request for public comment.../CR-7135, ``Compensatory and Alternative Regulatory Measures for Nuclear Power Plant Fire...

  9. Nuclear resonance scattering measurement of human iron stores

    SciTech Connect

    Wielopolski, L.; Ancona, R.C.; Mossey, R.T.; Vaswani, A.N.; Cohn, S.H.

    1985-07-01

    Hepatic iron stores were measured noninvasively in 31 patients (thalassemia, hemodialysis, hemosiderosis, refractory anemia) with suspected iron overload, employing a nuclear resonance scattering (NRS) technique. The thalassemia patients were undergoing desferrioxamine chelation therapy during the NRS measurements. The hemodialysis patients were measured before chelation therapy. Iron levels measured by NRS were in general agreement with those determined in liver biopsies by atomic absorption spectroscopy. In addition, NRS measurements from the thorax of some of these patients suggest that this method may also prove useful for clinical assessment of cardiac iron.

  10. Electrically tunable hole g factor of an optically active quantum dot for fast spin rotations

    NASA Astrophysics Data System (ADS)

    Prechtel, Jonathan H.; Maier, Franziska; Houel, Julien; Kuhlmann, Andreas V.; Ludwig, Arne; Wieck, Andreas D.; Loss, Daniel; Warburton, Richard J.

    2015-04-01

    We report a large g factor tunability of a single hole spin in an InGaAs quantum dot via an electric field. The magnetic field lies in the in-plane direction x , the direction required for a coherent hole spin. The electrical field lies along the growth direction z and is changed over a large range, 100 kV/cm. Both electron and hole g factors are determined by high resolution laser spectroscopy with resonance fluorescence detection. This, along with the low electrical-noise environment, gives very high quality experimental results. The hole g factor ghx depends linearly on the electric field Fz,d ghx/d Fz=(8.3 ±1.2 ) ×10-4 cm/kV, whereas the electron g factor gex is independent of electric field d gex/d Fz=(0.1 ±0.3 ) ×10-4 cm/kV (results averaged over a number of quantum dots). The dependence of ghx on Fz is well reproduced by a 4 ×4 k .p model demonstrating that the electric field sensitivity arises from a combination of soft hole confining potential, an In concentration gradient, and a strong dependence of material parameters on In concentration. The electric field sensitivity of the hole spin can be exploited for electrically driven hole spin rotations via the g tensor modulation technique and based on these results, a hole spin coupling as large as ˜1 GHz can be envisaged.

  11. Using Nuclear Magnetic Resonance Spectroscopy for Measuring Ternary Phase Diagrams

    ERIC Educational Resources Information Center

    Woodworth, Jennifer K.; Terrance, Jacob C.; Hoffmann, Markus M.

    2006-01-01

    A laboratory experiment is presented for the upper-level undergraduate physical chemistry curriculum in which the ternary phase diagram of water, 1-propanol and n-heptane is measured using proton nuclear magnetic resonance (NMR) spectroscopy. The experiment builds upon basic concepts of NMR spectral analysis, typically taught in the undergraduate…

  12. Electron impact cross section measurements related to 'nuclear pumping'

    NASA Technical Reports Server (NTRS)

    Trajmar, S.

    1979-01-01

    In direct nuclear pumped lasers the high energy fission fragments generate a large number of secondary electrons and these electrons are mainly responsible for achieving the population inversion in the lasing media. Laboratory measurements concerned with these electron impact processes are summarized and new results are presented on rare gases, N2, CO, CF3I and UF6.

  13. Measurement of nuclear dependence of pT at Fermilab

    NASA Astrophysics Data System (ADS)

    Wang, Suyin; E906/SeaQuest Collaboration

    2015-10-01

    The suppression of JPsi and Psi' production in the heavy ion collisions relative to their production in the p+p collisions has been proposed as one of the important signatures of the quark-gluon plasma (QGP) formation. The nuclear dependence of JPsi and Psi' production in the p+A collisions is essential to characterize the important baseline of the cold nuclear matter effect in both the initial and final states of collisions. In addition the final-state effect can be further differentiated in comparison with the nuclear dependence of Drell-Yan process. Fermilab E906/SeaQuest is a fixed-target experiment where the JPsi, Psi' and Drell-Yan productions from 120-GeV proton beam colliding with protons and various nuclear targets are measured simultaneously via the dimuon channel. In this talk we will report the recent progress of nuclear dependence of these productions as a function of the transverse momentum of dimuon from E906/SeaQuest's measurements. The results will be compared to those of E866 experiment obtained at higher beam energies. SuYin Wang is with Institute of Physics, Academia Sinica, Taiwan, and Particle Physics Division, Fermi National Accelerator Laboratory, USA. She is also a Ph.D. student from Department of Physics, National Kaohsiung Normal University, Taiwan.

  14. Nuclear fragmentation measurements for hadrontherapy and space radiation protection

    SciTech Connect

    De Napoli, M.; Agodi, C.; Blancato, A. A.; Cavallaro, M.; Cirrone, G. A. P.; Cuttone, G.; Sardina, D.; Scuderi, V.; Battistoni, G.; Bondi, M.; Cappuzzello, F.; Carbone, D.; Nicolosi, D.; Raciti, G.; Tropea, S.; Giacoppo, F.; Morone, M. C.; Pandola, L.; Rapisarda, E.; Romano, F.; and others

    2013-04-19

    Nuclear fragmentation measurements are necessary in hadrontherapy and space radiation protection, to predict the effects of the ion nuclear interactions within the human body. Nowadays, a very limited set of carbon fragmentation cross sections has been measured and in particular, to our knowledge, no double differential fragmentation cross sections at intermediate energies are available in literature. We have measured the double differential cross sections and the angular distributions of the secondary fragments produced in the {sup 12}C fragmentation at 62 AMeV on a thin carbon target. The experimental data have been also used to benchmark the prediction capability of the Geant4 Monte Carlo code at intermediate energies, where it was never tested before.

  15. Nuclear Data Measurements for 21st Century Reactor Physics Applications

    SciTech Connect

    Rahmat Aryaeinejad; Jerald D. Cole; Mark W. Drigert; James K. Jewell; Christopher A. McGrath; David W. Nigg; Edward L. Reber

    2003-03-01

    The United States Department of Energy (DOE), Office of Nuclear Energy (NE) has embarked on a long-term program to significantly advance the science and technology of nuclear energy. This is in response to the overall national plan for accelerated development of domestic energy resources on several fronts, punctuated by recent dramatic events that have emphasized the need for the US to reduce its dependence on foreign petroleum supplies. Key aspects of the DOE-NE agenda are embodied in the Generation-IV (Gen-IV) advanced nuclear energy systems development program and in the Advanced Fuel Cycle (AFC) program. The planned efforts involve near-term and intermediate-term improvements in fuel utilization and recycling in current nuclear power reactor systems as well as the longer-term development of new nuclear energy systems that offer much improved fuel utilization and proliferation resistance, along with continued advances in operational safety. The success of the overall NE effort will depend not only on sophisticated system development and engineering, but also on the advances in the supporting sciences and technologies. Of these, one of the most important is the improvement of the relevant fundamental nuclear science data bases, especially the evaluated neutron interaction cross section files that serve as the foundation of all reactor system designs, operating strategies, and fuel cycle engineering activities. The new concepts for reactors and fuel cycles involve the use of transuranic nuclides that were previously of little interest, and where experimentally measured information is lacking. The current state of the cross section database for some of these nuclides is such that design computations for advanced fast-spectrum reactor systems and fuel cycles that incorporate such materials in significant quantities are meaningful only for approximate conceptual applications. No actual system could reliably be designed according to currently accepted standards, nor

  16. Thermal measurements in the nuclear winter fire test

    SciTech Connect

    Schneider, M.E.; Keltner, N.R.; Kent, L.A.

    1989-01-01

    In March, 1987, a large open pool fire test was performed to provide test measurements to help define the thermal characteristics of large open pool fires and estimates of the smoke source term for the nuclear winter (global effects) scenario. This report will present the results of the thermal measurements as well as comparisons with previous test results. These measurements included flame temperatures, heat fluxes to a variety of calorimeters, and gas velocities in the lower flame regions. 13 refs., 76 figs., 7 tabs.

  17. Light nuclear charge measurement with Alpha Magnetic Spectrometer Electromagnetic Calorimeter

    NASA Astrophysics Data System (ADS)

    Basara, Laurent; Choutko, Vitaly; Li, Qiang

    2016-06-01

    The Alpha Magnetic Spectrometer (AMS) is a high energy particle detector installed and operating on board of the International Space Station (ISS) since May 2011. So far more than 70 billion cosmic ray events have been recorded by AMS. In the present paper the Electromagnetic Calorimeter (ECAL) detector of AMS is used to measure cosmic ray nuclear charge magnitudes up to Z=10. The obtained charge magnitude resolution is about 0.1 and 0.3 charge unit for Helium and Carbon, respectively. These measurements are important for an accurate determination of the interaction probabilities of various nuclei with the AMS materials. The ECAL charge calibration and measurement procedures are presented.

  18. Relativistic CI+all-order calculations of U III energies, g-factors, transition rates and lifetimes

    NASA Astrophysics Data System (ADS)

    Savukov, Igor; Safronova, Ulyana; Safronova, Marianna

    2016-05-01

    Excitation energies, term designations, g-factors, transition rates and lifetimes of U2+ are determined using a relativistic configuration interaction (CI) + all-order (linearized coupled-cluster, LCC) approach. The all-order energies are compared with CI+many-body-perturbation-theory (MBPT) and available experimental energies. Close agreement has been found with experiment, within hundreds of cm-1. In addition, lifetimes of higher levels have been calculated for comparison with three experimentally measured lifetimes, and close agreement was found within t he experimental error. CI-LCC calculations constitute a benchmark test of the CI+all-order method in complex relativistic systems such as actinides and their ions with many valence electrons. The theory yields many energy levels, g-factors, transition rates, and lifetimes of U2+ that are not available from experiment. The theory can be applied to other multi-valence atoms and ions, which would be of interest to many applications. The work of I. Savukov has been performed under the auspices of the U.S. DOE by LANL under Contract No. DE-AC52-06NA25396.M.S.S. acknowledges support from the Gordon Godfrey Fellowship program, UNSW and U.S. NSF Grant No. PHY-1404156.

  19. Effective g-factors of carriers in inverted InAs/GaSb bilayers

    NASA Astrophysics Data System (ADS)

    Mu, Xiaoyang; Sullivan, Gerard; Du, Rui-Rui

    2016-01-01

    We perform tilt-field transport experiment on inverted InAs/GaSb, which hosts quantum spin Hall insulator. By means of coincidence method, Landau level (LL) spectra of electron and hole carriers are systematically studied at different carrier densities tuned by gate voltages. When Fermi level stays in the conduction band, we observe LL crossing and anti-crossing behaviors at odd and even filling factors, respectively, with a corresponding g-factor of 11.5. It remains nearly constant for varying filling factors and electron densities. On the contrary, for GaSb holes, only a small Zeeman splitting is observed even at large tilt angles, indicating a g-factor of less than 3.

  20. Further investigation of g factors for the lead monofluoride ground state

    DOE PAGESBeta

    Skripnikov, L. V.; Petrov, A. N.; Titov, A. V.; Mawhorter, R. J.; Baum, A. L.; Sears, T. J.; Grabow, J. -U.

    2015-09-15

    We report the results of our theoretical study and analysis of earlier experimental data for the g-factor tensor components of the ground 2II1/2 state of the free PbF radical. These values obtained both within the relativistic coupled-cluster method combined with the generalized relativistic effective core potential approach and with our fit of the experimental data from [R. J. Mawhorter, B. S. Murphy, A. L. Baum, T. J. Sears, T. Yang, P. M. Rupasinghe, C. P. McRaven, N. E. Shafer-Ray, L. D. Alphei, and J.-U. Grabow, Phys. Rev. A 84, 022508 (2011); A. L. Baum, B.A. thesis, Pomona College, 2011]. Themore » obtained results agree very well with each other but contradict the previous fit performed in the cited works. Our final prediction for g factors is G∥=0.081(5),G⊥=–0.27(1).« less

  1. Tuning g factors of core-shell nanoparticles by controlled positioning of magnetic impurities

    NASA Astrophysics Data System (ADS)

    Sanders, G. D.; Musfeldt, J. L.; Stanton, C. J.

    2016-02-01

    We present a theoretical platform for modeling the electronic and magneto-optic properties of magnetically doped core-shell nanoparticles that has, as a central prediction, a mechanism by which the g factors in these nanoparticles can be tuned over a wide range by controlled positioning of magnetic impurities. We illustrate this effect for wide-gap Mn-doped CdS-ZnS core-shell particles and point out several unexpected trends that merit extended experimental investigation. The ability to tune g factors will make core-shell nanostructures viable candidates for spintronic applications, and the comprehensive modeling approach outlined here will be a powerful tool for predicting their properties as well as for optimizing the design of novel spintronic devices.

  2. Further investigation of g factors for the lead monofluoride ground state

    NASA Astrophysics Data System (ADS)

    Skripnikov, L. V.; Petrov, A. N.; Titov, A. V.; Mawhorter, R. J.; Baum, A. L.; Sears, T. J.; Grabow, J.-U.

    2015-09-01

    We report the results of our theoretical study and analysis of earlier experimental data for the g -factor tensor components of the ground 2Π1 /2 state of the free PbF radical. The values were obtained both within the relativistic coupled-cluster method combined with the generalized relativistic effective core potential approach and with our fit of the experimental data from [R. J. Mawhorter, B. S. Murphy, A. L. Baum, T. J. Sears, T. Yang, P. M. Rupasinghe, C. P. McRaven, N. E. Shafer-Ray, L. D. Alphei, and J.-U. Grabow, Phys. Rev. A 84, 022508 (2011), 10.1103/PhysRevA.84.022508; A. L. Baum, B.A. thesis, Pomona College, 2011]. The obtained results agree very well with each other but contradict the previous fit performed in the cited works. Our final prediction for g factors is G∥=0.081 (5 ) ,G⊥=-0.27 (1 ) .

  3. Precision Penning Trap Mass Measurements for Nuclear Structure at Triumf

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, A. A.; Dilling, J.; Andreoiu, C.; Brunner, T.; Chaudhuri, A.; Chowdhury, U.; Delheij, P.; Ettenauer, S.; Frekers, D.; Gallant, A. T.; Grossheim, A.; Gwinner, G.; Lennarz, A.; Mané, E.; Pearson, M. R.; Schultz, B. E.; Simon, M. C.; Simon, V. V.

    2013-03-01

    Precision determinations of ground state or even isomeric state masses reveal fingerprints of nuclear structure. In particular at the limits at existence for very neutron-rich or deficient isotopes, this allows one to find detailed information about nuclear structure from separation energies or binding energies. This is important to test theoretical predictions or to refine model approaches, for example for new "magic numbers," as predicted around N = 34, where strong indications exist that the inclusion of NNN forces in theoretical calculations for Ca isotopes leads to significantly better predictions for ground state binding energies. Similarly, halo nuclei present an excellent application for ab-initio theory, where ground state properties, like masses and radii, present prime parameters for testing our understanding of nuclear structure. Precision mass determinations at TRIUMF are carried out with the TITAN (TRIUMF's Ion Trap for Atomic and Nuclear science) system. It is an ion trap setup coupled to the on-line facility ISAC. TITAN has measured masses of isotopes as short-lived as 9 ms (almost an order of magnitude shorter-lived than any other Penning trap system) and the only one with charge breeding capabilities, a feature that allows us to boost the precision by almost 2 orders of magnitude. We recently were able to make use of this feature by measuring short-lived Rb-isotopes, up to 74Rb, and reaching the 12+ charge state, which together with other improvements lead to an increase in precision by a factor 36.

  4. Temperature dependence of the electron spin g factor in CdTe and InP

    NASA Astrophysics Data System (ADS)

    Pfeffer, Pawel; Zawadzki, Wlodek

    2012-04-01

    Temperature dependence of the electron spin g factors in bulk CdTe and InP is calculated and compared with experiment. It is assumed that the only modification of the band structure related to temperature is a dilatation change in the fundamental energy gap. The dilatation changes of fundamental gaps are calculated for both materials using available experimental data. Computations of the band structures in the presence of a magnetic field are carried out employing five-level P.p model appropriate for medium-gap semiconductors. In particular, the model takes into account spin splitting due to bulk inversion asymmetry (BIA) of the materials. The resulting theoretical effective masses and g factors increase with electron energy due to band nonparabolicity. Average g values are calculated by summing over populated Landau and spin levels properly accounting for the thermal distribution of electrons in the band. It is shown that the spin splitting due to BIA in the presence of a magnetic field gives observable contributions to g values. Our calculations are in good agreement with experiments in the temperature range of 0 K to 300 K for CdTe and 0 K to 180 K for InP. The temperature dependence of g is stronger in CdTe than in InP due to different signs of band-edge g values in the two materials. Good agreement between the theory and experiments strongly indicates that the temperature dependence of spin g factors is correctly explained. In addition, we discuss formulas for the energy dependence of spin g factor due to band nonparabolicity, which are liable to misinterpretation.

  5. Exchange enhancement of the electron g factor in strained InGaAs/InP heterostructures

    SciTech Connect

    Krishtopenko, S. S.; Maremyanin, K. V. Kalinin, K. P.; Spirin, K. E.; Gavrilenko, V. I.; Baidus, N. V.; Zvonkov, B. N.

    2015-02-15

    The exchange enhancement of the electron g factor in strained InGaAs/InP heterostructures with a two-dimensional electron gas is studied. Analysis of the temperature dependence of the resistance in the minima of the Shubnikov-de Haas oscillations in perpendicular magnetic fields up to 12 T in the vicinity of the odd filling factors of the Landau levels yields the values of the effective electron Lande factor g* from −8.6 to −10.1. The experimental values are compared with the results of theoretical calculations of the g factor of quasiparticles. The calculations are performed using an eight-band k · p Hamiltonian and take into account exchange interaction in the two-dimensional electron gas. It is shown that, under the conditions of a large overlap between the spin-split Landau levels, the maximum value of the quasiparticle g factor can be attained in the vicinity of even filling factors. This is caused by the nonparabolicity of the electron dispersion relation.

  6. Measurements of ϒ Production and Nuclear Modification Factor at STAR

    NASA Astrophysics Data System (ADS)

    Kesich, Anthony

    2013-08-01

    Thermal suppression of quarkonium production in heavy-ion collisions, due to Debye screening of the quark-antiquark potential, has been proposed as a clear signature of Quark-Gluon Plasma (QGP) formation. At RHIC energies, the ϒ meson is a clean probe of the early system due to negligible levels of enhancement from bbbar recombination and non-thermal suppression from co-mover absorption. We report on our measurement of the ϒ →e+e- cross section in Au+Au collisions at √{sNN} = 200 GeV. We compute the Nuclear Modification Factor by comparing these results to new p+p measurements from 2009 (21pb-1 in 2009 compared to 7.9pb-1 in 2006). In order to have a complete assessment of both hot and cold nuclear matter effects on Upsilon production we also report on results from d+Au collisions.

  7. A nuclear data approach for the Hubble constant measurements

    SciTech Connect

    Pritychenko, B.

    2015-06-09

    An extraordinary number of Hubble constant measurements challenges physicists with selection of the best numerical value. The standard U.S. Nuclear Data Program (USNDP) codes and procedures have been applied to resolve this issue. The nuclear data approach has produced the most probable or recommended Hubble constant value of 67.00(770) (km/sec)/Mpc. This recommended value is based on the last 25 years of experimental research and includes contributions from different types of measurements. The present result implies (14.6±1.7) x 109 years as a rough estimate for the age of the Universe. The complete list of recommended results is given and possible implications are discussed.

  8. Electron and hole g factors in InAs/InAlGaAs self-assembled quantum dots emitting at telecom wavelengths

    NASA Astrophysics Data System (ADS)

    Belykh, V. V.; Greilich, A.; Yakovlev, D. R.; Yacob, M.; Reithmaier, J. P.; Benyoucef, M.; Bayer, M.

    2015-10-01

    We extend the range of quantum dot (QD) emission energies where electron and hole g factors have been measured to the practically important telecom range. The spin dynamics in InAs/In0.53Al0.24Ga0.23As self-assembled QDs with emission wavelengths at about 1.6 μ m grown on InP substrate is investigated by pump-probe Faraday rotation spectroscopy in a magnetic field. Pronounced oscillations on two different frequencies, corresponding to the QD electron and hole spin precessions about the field, are observed from which the corresponding g factors are determined. The electron g factor of about -1.9 has the largest negative value so far measured for III-V QDs by optical methods. This value, as well as the g factors reported for other III-V QDs, differ from those expected for bulk semiconductors at the same emission energies, and this difference increases significantly for decreasing energies.

  9. Method and apparatus for measuring nuclear magnetic properties

    DOEpatents

    Weitekamp, Daniel P.; Bielecki, Anthony; Zax, David B.; Zilm, Kurt W.; Pines, Alexander

    1987-01-01

    A method for studying the chemical and structural characteristics of materials is disclosed. The method includes placement of a sample material in a high strength polarizing magnetic field to order the sample nucleii. The condition used to order the sample is then removed abruptly and the ordering of the sample allowed to evolve for a time interval. At the end of the time interval, the ordering of the sample is measured by conventional nuclear magnetic resonance techniques.

  10. Method and apparatus for measuring nuclear magnetic properties

    DOEpatents

    Weitekamp, D.P.; Bielecki, A.; Zax, D.B.; Zilm, K.W.; Pines, A.

    1987-12-01

    A method for studying the chemical and structural characteristics of materials is disclosed. The method includes placement of a sample material in a high strength polarizing magnetic field to order the sample nuclei. The condition used to order the sample is then removed abruptly and the ordering of the sample allowed to evolve for a time interval. At the end of the time interval, the ordering of the sample is measured by conventional nuclear magnetic resonance techniques. 5 figs.

  11. Measurement and Characterization of Nuclear Material at Idaho National Laboratory

    SciTech Connect

    J. L. Dolan; M. Flaska; S. A. Pozzi; D. L. Chichester

    2009-07-01

    A measurement plan and preliminary Monte Carlo simulations are presented for the investigation of well-defined mixed-oxide fuel pins. Measurement analysis including pulse-height distributions and time-dependent cross-correlation functions will be performed separately for neutrons and gamma rays. The utilization of Monte Carlo particle transport codes, specifically MCNP-PoliMi, is discussed in conjunction with the anticipated measurements. Four EJ-309 liquid scintillation detectors with an accurate pulse timing and digital, offline, optimized pulse-shape discrimination method will be used to prove the dependency of pulse-height distributions, cross-correlation functions, and material multiplicities upon fuel pin composition, fuel pin quantity, and detector geometry. The objective of the measurements and simulations is to identify novel methods for describing mixed-oxide fuel samples by relating measured quantities to fuel characteristics such as criticality, mass quantity, and material composition. This research has applications in nuclear safeguards and nonproliferation.

  12. Experiments with Exotic Spin-Oriented Nuclear Beams and Examples of Nuclear Moment Measurements

    NASA Astrophysics Data System (ADS)

    Balabanski, D. L.; Neyens, G.; Borremans, D.; Coulier, N.; Daugas, J. M.; Teughels, S.; Georgiev, G.; Lewitowicz, M.; de Oliveira Santos, F.; Penionzhkevich, Yu. E.

    2002-04-01

    An overview of a series of recent experiments aimed at the determination of the moments of exotic nuclei is presented. The spin-orientation: spin-alignment and spin-polarization of the nuclear ensemble, which is produced in fragmentation reactions, is of utmost importance for these studies. The discussion emphasizes on the open problems related to the production and the preservation of the orientation during the experiments. Pros and contras for experiments at both, intermediate and high energies are considered. Examples from nuclear moment measurements, which were performed using the LISE-III spectrometer at GANIL, are provided. The spin-alignment and the spin-polarization of the nuclear ensemble were studied by the β-LMR, β-NMR and TDPAD experimental techniques. The experimental results are discussed in the framework of the kinematical model of the fragmentation reaction.

  13. Indirect measurement of nuclear reactions of astrophysical interest

    SciTech Connect

    Liu, W. P.; Li, Z. H.; Bai, X. X.; Wang, Y. B.; Guo, B.; Lian, G.; Su, J.; Zeng, S.; Wang, B. X.; Yan, S. Q.; Li, Y. J.; Li, E. T.; Jin, S. J.

    2010-05-12

    Systematic indirect measurements of nuclear astrophysical reactions using the unstable ion beam facility GIRAFFE in CIAE were performed. We have measured the angular distributions of transfer reactions, such as {sup 8}Li(d,p){sup 9}Li, {sup 8}Li(d,n){sup 9}Be and {sup 8}Li(p,d){sup 7}Li in inverse kinematics, and derived the astrophysical S-factors or reaction rates for {sup 8}Li(n,gamma){sup 9}Li and {sup 8}Li(p,gamma){sup 9}Be by using asymptotic normalization coefficient (ANC) or spectroscopic factor methods.

  14. Senate examines measures to improve nuclear safety following Japan disaster

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-03-01

    One year after Japan suffered a devastating magnitude 9.0 earthquake and the resulting tsunami and nuclear disaster, the U.S. Nuclear Regulatory Commission (NRC) has taken a number of measures to try to ensure that nuclear plants in the United States are safe from natural hazards. At a U.S. Senate hearing on 15 March, NRC chair Gregory Jaczko announced that the commission had issued three key orders and several requests for information on 12 March that plant licensees must follow, and that NRC also plans to take additional actions. However, the commission is not moving quickly enough in some areas, such as ensuring that all plants are safe from seismic hazards, including those in areas with low seismic activity, according to Jaczko's testimony before the Senate Committee on Environment and Public Works (EPW) and the Subcommittee on Clean Air and Nuclear Safety. The 12 March orders require licensees to have strategies to maintain or restore core cooling, containment, and spent-fuel pool cooling capabilities "following a beyond-design-basis extreme natural event" and have a reliable indication of the water level in spent-fuel storage pools.

  15. Gamma Ray Mirrors for Direct Measurement of Spent Nuclear Fuel

    SciTech Connect

    Pivovaroff, Dr. Michael J.; Ziock, Klaus-Peter; Harrison, Mark J; Soufli, Regina

    2014-01-01

    Direct measurement of the amount of Pu and U in spent nuclear fuel represents a challenge for the safeguards community. Ideally, the characteristic gamma-ray emission lines from different isotopes provide an observable suitable for this task. However, these lines are generally lost in the fierce flux of radiation emitted by the fuel. The rates are so high that detector dead times limit measurements to only very small solid angles of the fuel. Only through the use of carefully designed view ports and long dwell times are such measurements possible. Recent advances in multilayer grazing-incidence gamma-ray optics provide one possible means of overcoming this difficulty. With a proper optical and coating design, such optics can serve as a notch filter, passing only narrow regions of the overall spectrum to a fully shielded detector that does not view the spent fuel directly. We report on the design of a mirror system and a number of experimental measurements.

  16. Charged fusion product loss measurements using nuclear activation.

    PubMed

    Bonheure, G; Hult, M; González de Orduña, R; Arnold, D; Dombrowski, H; Laubenstein, M; Wieslander, E; Vermaercke, P; Murari, A; Popovichev, S; Mlynar, J

    2010-10-01

    In ITER, α particle loss measurements will be required in order to understand the alpha particle physics. Techniques capable of operating in a fusion reactor environment need further development. Recent experimental studies on JET demonstrated the potential of nuclear activation to measure the flux of escaping MeV ions. New results from MeV ion induced activation of metallic, ceramic, and crystal samples placed near the plasma edge are reported. Activation products were measured as function of orientation with respect to the magnetic field as well as function of the distance to the plasma. Sample activity was measured using ultralow-level gamma-ray spectrometry. Distribution of 14.68 MeV fusion proton induced activation products is strongly anisotropic in agreement with simulations and falls off sharply with increasing distance to the plasma. Prospects for using the technique in ITER are discussed. PMID:21058458

  17. Nuclear data measurements at the new NFS facility at GANIL

    NASA Astrophysics Data System (ADS)

    Gustavsson, C.; Pomp, S.; Scian, G.; Lecolley, F.-R.; Tippawan, U.; Watanabe, Y.

    2012-10-01

    The NFS (Neutrons For Science) facility is part of the SPRIAL 2 project at GANIL, Caen, France. The facility is currently under construction and the first beam is expected in early 2013. NFS will have a white neutron source covering the 1-40 MeV energy range with a neutron flux higher than comparable facilities. A quasi-mono-energetic neutron beam will also be available. In these energy ranges, especially above 14 MeV, there is a large demand for neutron-induced data for a wide range of applications involving dosimetry, medical therapy, single-event upsets in electronics and nuclear energy. Today, there are a few or no cross section data on reactions such as (n, fission), (n, xn), (n, p), (n, d) and (n, α). We propose to install experimental equipment for measuring neutron-induced light-charged particle production and fission relative to the H(n, p) cross section. Both the H(n, p) cross section and the fission cross section for 238U are important reference cross sections used as standards for many other experiments. Nuclear data for certain key elements, such as closed shell nuclei, are also of relevance for the development of nuclear reaction models. Our primary intention is to measure charged particle production (protons, deuterons and alphas) from 12C, 16O, 28Si and 56Fe and neutron-induced fission cross sections from 238U and 232Th.

  18. Temperature measuring analysis of the nuclear reactor fuel assembly

    SciTech Connect

    Urban, F. E-mail: zdenko.zavodny@stuba.sk; Kučák, L. E-mail: zdenko.zavodny@stuba.sk; Bereznai, J. E-mail: zdenko.zavodny@stuba.sk; Závodný, Z. E-mail: zdenko.zavodny@stuba.sk; Muškát, P. E-mail: zdenko.zavodny@stuba.sk

    2014-08-06

    Study was based on rapid changes of measured temperature values from the thermocouple in the VVER 440 nuclear reactor fuel assembly. Task was to determine origin of fluctuations of the temperature values by experiments on physical model of the fuel assembly. During an experiment, heated water was circulating in the system and cold water inlet through central tube to record sensitivity of the temperature sensor. Two positions of the sensor was used. First, just above the central tube in the physical model fuel assembly axis and second at the position of the thermocouple in the VVER 440 nuclear reactor fuel assembly. Dependency of the temperature values on time are presented in the diagram form in the paper.

  19. Trojan Horse technique to measure nuclear astrophysics rearrangement reactions

    NASA Astrophysics Data System (ADS)

    Spitaleri, Claudio

    2013-03-01

    The knowledge of nucleosynthesis and of energy production in stars requires an increasingly precise measurement of nuclear fusion reactions at the Gamow energy. Because of the Coulomb barrier reaction cross sections in astrophysics cannot be accessed directly at ultra -low energies, unless very favorable conditions are met. Moreover, the energies characterizing nuclear processes in several astrophysical contexts are so low that the presence of atomic electrons must be taken into account. Theoretical extrapolations of available data are then needed to derive astrophysical S(E)-factors. To overcome these experimental difficulties the Trojan Horse Method (THM) has been introduced. The method provides a valid alternative path to measure unscreened low-energy cross sections of reactions between charged particles, and to retrieve information on the electron screening potential when ultra-low energy direct measurements are available. While the theory has been discussed in detail in some theoretical works, present in the scientific literature, also in relation to different types of excitation functions (e.g. non-resonant and resonant), work on detailed methodology used to extract the events to be considered for the bare nucleus cross section measurements is still on going. In this work we will present some critical points in the application of THM that deserve to be discussed in more detail.

  20. Zeeman splitting and g factor of the 1s{sup 2}2s{sup 2}2p {sup 2}P{sub 3/2} and {sup 2}P{sub 1/2} levels in Ar{sup 13+}

    SciTech Connect

    Soria Orts, R.; Crespo Lopez-Urrutia, J. R.; Bruhns, H.; Gonzalez Martinez, A. J.; Harman, Z.; Jentschura, U. D.; Keitel, C. H.; Lapierre, A.; Tawara, H.; Ullrich, J.; Tupitsyn, I. I.; Volotka, A. V.

    2007-11-15

    The Zeeman line components of the magnetic-dipole (M1) 1s{sup 2}2s{sup 2}2p {sup 2}P{sub 1/2}-{sup 2}P{sub 3/2} transition in boronlike Ar{sup 13+} were experimentally resolved by high-precision emission spectroscopy using the Heidelberg electron beam ion trap. We determined the gyromagnetic (g) factors of the ground and first-excited levels to be g{sub 1/2}=0.663(7) and g{sub 3/2}=1.333(2), respectively. This corresponds to a measurement of the g factor of a relativistic electron in a bound non-S state of a multielectron ion with a 1.5 parts-per-thousand accuracy. The results are compared to theoretical calculations by means of the configuration interaction Dirac-Fock-Sturmian method including electron correlation effects and additional quantum electrodynamic corrections. Our measurements show that the classical Lande g factor formula is sufficiently accurate to the present level of accuracy in few-electron ions of medium nuclear charge number Z.

  1. Measurement of heat transfer coefficients by nuclear magnetic resonance.

    PubMed

    Gultekin, David H; Gore, John C

    2008-11-01

    We demonstrate an experimental method for the measurement of heat transfer coefficient for a fluid system by magnetic resonance imaging. In this method, the temporal variation of thermally induced nuclear shielding is monitored and the average heat transfer coefficient is measured as a function of fluid velocity. We examine the cases of natural convection and forced convection at fluid velocity up to 0.8 m s(-1). These cases correspond to low dimensionless Biot (Bi) number where the heat transfer is limited by thermal convection. We demonstrate the NMR method for two simple geometries, a cylinder and a sphere, to experimentally determine the heat transfer coefficient (h) in two NMR imaging and spectroscopy systems through measuring three NMR parameters, the chemical shift, magnetization and spin self diffusion coefficient. PMID:18524523

  2. Measurement of nuclear-physical characteristics of radionuclides

    SciTech Connect

    Geidel'man, A.M.; Egorov, Yu.S.; Nedovesov, V.G.; Shchukin, G.E.

    1987-08-01

    This article provides the revised data for the nuclear-physical characteristics (NPC) measurements of seven radionuclides: /sup 238/Pu, /sup 239/Pu, /sup 55/Fe, /sup 125m/Te, /sup 119m/Sn, /sup 75/Se, and /sup 120/Tm. These radionuclides are widely used in the preparation of various radionuclide products, standard sources of ionizing radiation, and standard solutions. The emission characteristics data for the nuclides may be used for calibration of semiconductor spectrometers with regard to energy and efficiency.

  3. Anisotropy of in-plane hole g factor in CdTe/ZnTe quantum dots

    NASA Astrophysics Data System (ADS)

    Bogucki, A.; Smoleński, T.; Goryca, M.; Kazimierczuk, T.; Kobak, J.; Pacuski, W.; Wojnar, P.; Kossacki, P.

    2016-06-01

    Optical studies of a bright exciton provide only limited information about the hole anisotropy in a quantum dot. In this work we present a universal method to study heavy-hole anisotropy using a dark exciton in a moderate in-plane magnetic field. By analysis of the linear polarization of the dark exciton photoluminescence we identify two distinct contributions to the hole g factor: the anisotropic one resulting in a fixed orientation of the dark exciton polarization for any direction of the magnetic field and the quasi-isotropic contribution, due to which the polarization orientation rotates with the magnetic field, but in the opposite direction. We employ the proposed method for a number of individual self-assembled CdTe/ZnTe quantum dots, demonstrating a variety of behaviors of in-plane hole g factor: from almost fully anisotropic to almost quasi-isotropic. We conclude that, in general, both contributions play an important role and neither contribution can be neglected.

  4. Electric dipole spin resonance in systems with a valley-dependent g factor

    NASA Astrophysics Data System (ADS)

    Rančić, Marko J.; Burkard, Guido

    2016-05-01

    In this theoretical study we qualitatively and quantitatively investigate the electric dipole spin resonance (EDSR) in a single Si/SiGe quantum dot in the presence of a magnetic field gradient, e.g., produced by a ferromagnet. We model a situation in which the control of electron spin states is achieved by applying an oscillatory electric field, inducing real-space oscillations of the electron inside the quantum dot. One of the goals of our study is to present a microscopic theory of valley-dependent g factors in Si/SiGe quantum dots and investigate how valley relaxation combined with a valley-dependent g factor leads to a novel electron spin dephasing mechanism. Furthermore, we discuss the interplay of spin and valley relaxations in Si/SiGe quantum dots. Our findings suggest that the electron spin dephases due to valley relaxation, and are in agreement with recent experimental studies [Nat. Nanotechnol. 9, 666 (2014), 10.1038/nnano.2014.153].

  5. Superallowed nuclear beta decay: Precision measurements for basic physics

    SciTech Connect

    Hardy, J. C.

    2012-11-20

    For 60 years, superallowed 0{sup +}{yields}0{sup +} nuclear beta decay has been used to probe the weak interaction, currently verifying the conservation of the vector current (CVC) to high precision ({+-}0.01%) and anchoring the most demanding available test of the unitarity of the Cabibbo-Kobayashi-Maskawa (CKM) matrix ({+-}0.06%), a fundamental pillar of the electroweak standard model. Each superallowed transition is characterized by its ft-value, a result obtained from three measured quantities: the total decay energy of the transition, its branching ratio, and the half-life of the parent state. Today's data set is composed of some 150 independent measurements of 13 separate superallowed transitions covering a wide range of parent nuclei from {sup 10}C to {sup 74}Rb. Excellent consistency among the average results for all 13 transitions - a prediction of CVC - also confirms the validity of the small transition-dependent theoretical corrections that have been applied to account for isospin symmetry breaking. With CVC consistency established, the value of the vector coupling constant, G{sub V}, has been extracted from the data and used to determine the top left element of the CKM matrix, V{sub ud}. With this result the top-row unitarity test of the CKM matrix yields the value 0.99995(61), a result that sets a tight limit on possible new physics beyond the standard model. To have any impact on these fundamental weak-interaction tests, any measurement must be made with a precision of 0.1% or better - a substantial experimental challenge well beyond the requirements of most nuclear physics measurements. I overview the current state of the field and outline some of the requirements that need to be met by experimentalists if they aim to make measurements with this high level of precision.

  6. Indirect measurements of nuclear astrophysics reactions at CIAE

    SciTech Connect

    Liu Weiping; Li Zhihong; Bai Xixiang; Wang Youbao; Lian Gang; Guo Bing; Zeng Sheng; Yan Shengquan; Wang Baoxiang; Su Jun; Shu Nengchuan; Chen Yongshou

    2006-11-02

    This paper described the nuclear astrophysical studies using the unstable ion beam facility GIRAFFE, by indirect measurements. We measured the angular distributions for some single proton or neutron transfer reactions, such as 7Be(d,n)8B, 11C(d,n)12N, 8Li(d,n)9Be, 8Li(d,p)9Li and 13N(d,n)14O in inverse kinematics, and derived the astrophysical S-factors or reaction rates of 7Be(p,{gamma})8B, 11C(p,{gamma})12N, 8Li(n,{gamma})9Li, 13N(p,{gamma})14O by asymptotic normalization coefficient, spectroscopic factor, and R-matrix approach at astrophysically relevant energies.

  7. Proton Nuclear Magnetic Resonance Relaxation Measurements in Frog Muscle

    PubMed Central

    Finch, Edward D.; Homer, Louis D.

    1974-01-01

    Proton nuclear magnetic resonance (NMR) relaxation measurements are reported for frog muscle as a function of temperature and Larmor frequency. Each T1ρ, T2, and T1 measurement covered a time domain sufficient to identify the average relaxation time for most intracellular water. Using regression analysis the data were fit with a model where intracellular water molecules are exchanging between a large compartment in which mobility is similar to ordinary water and a small compartment in which motion is restricted. The regression results suggest that: the restricted compartment exhibits a distribution of motions skewed toward that of free water; the residence time of water molecules in the restricted compartment is approximately 1 ms; and, the activation entropy for some water molecules in the restricted compartment is negative. PMID:4547668

  8. Safeguards Measurement Evaluation Program nuclear materials measurement data: Phase 1: Final report, 1985 through 1986

    SciTech Connect

    Cacic, C.G.

    1988-08-01

    The New Brunswick Laboratory has been tasked by the US Department of Energy Office of Safeguards and Security to assess and evaluate the adequacy of measurement technology as applied to materials accounting in US Department of Energy nuclear facilities. The Safeguards Measurement Evaluation Program was developed as a means to monitor and evaluate the quality and effectiveness of accounting measurements by site, material balance area, or unit process. Phase 1 of the Safeguards Measurement Evaluation Program, initiated during 1985, involved evaluation of the primary accountability measurement methods at six US Department of Energy Defense Programs facilities. Resulting data are presented and evaluated as indicators of current state-of-the-practice accountability measurement methodology, deficiencies in materials accounting practices, and areas for possible assistance in upgrading measurement capabilities. 22 figs., 5 tabs.

  9. Nuclear Technology Series. Course 11: Radiation Detection and Measurement.

    ERIC Educational Resources Information Center

    Technical Education Research Center, Waco, TX.

    This technical specialty course is one of thirty-five courses designed for use by two-year postsecondary institutions in five nuclear technician curriculum areas: (1) radiation protection technician, (2) nuclear instrumentation and control technician, (3) nuclear materials processing technician, (4) nuclear quality-assurance/quality-control…

  10. Holes localized in nanostructures in an external magnetic field: g-factor and mixing of states

    SciTech Connect

    Semina, M. A.; Suris, R. A.

    2015-06-15

    The energy spectrum and wave functions of holes in the valence band in semiconductor nanosystems, including quantum wells, quantum wires, and quantum dots, in an external magnetic field are theoretically investigated. The dependence of Zeeman splitting of the hole ground state upon variation in the size-quantization parameters with regard to the complex structure of the valence band and magnetic field-induced mixing of hole states is traced. Analytical formulas for describing the Zeeman effect in the valence band in the limiting cases of a quantum disk, spherically symmetric quantum dot, and quantum wire are presented. It is demonstrated that the g-factor of a hole is extremely sensitive to the hole-state composition (heavy or light hole) and, consequently, to the geometry of the size-quantization potential.

  11. Control of Majorana edge modes by a g-factor engineered nanowire spin transistor

    NASA Astrophysics Data System (ADS)

    De, Amrit; Kovalev, Alexey A.

    2014-11-01

    We propose the manipulation of Majorana edge states via hybridization and spin currents in a nanowire spin transistor. The spin transistor is based on a heterostructure nanowire comprising of semiconductors with large and small g-factors that form the topological and non-topological regions respectively. The hybridization of bound edge states results in spin currents and 4π-periodic torques, as a function of the relative magnetic field angle - an effect which is dual to the fractional Josephson effect. We establish relation between torques and spin-currents in the non-topological region where the magnetic field is almost zero and spin is conserved along the spin-orbit field direction. The angular momentum transfer could be detected by sensitive magnetic resonance force microscopy techniques.

  12. Electrical Control of g-Factor in a Few-Hole Silicon Nanowire MOSFET.

    PubMed

    Voisin, B; Maurand, R; Barraud, S; Vinet, M; Jehl, X; Sanquer, M; Renard, J; De Franceschi, S

    2016-01-13

    Hole spins in silicon represent a promising yet barely explored direction for solid-state quantum computation, possibly combining long spin coherence, resulting from a reduced hyperfine interaction, and fast electrically driven qubit manipulation. Here we show that a silicon-nanowire field-effect transistor based on state-of-the-art silicon-on-insulator technology can be operated as a few-hole quantum dot. A detailed magnetotransport study of the first accessible hole reveals a g-factor with unexpectedly strong anisotropy and gate dependence. We infer that these two characteristics could enable an electrically driven g-tensor-modulation spin resonance with Rabi frequencies exceeding several hundred mega-Hertz. PMID:26599868

  13. Use of mathematical modeling in nuclear measurements projects

    SciTech Connect

    Toubon, H.; Menaa, N.; Mirolo, L.; Ducoux, X.; Khalil, R. A.

    2011-07-01

    Mathematical modeling of nuclear measurement systems is not a new concept. The response of the measurement system is described using a pre-defined mathematical model that depends on a set of parameters. These parameters are determined using a limited set of experimental measurement points e.g. efficiency curve, dose rates... etc. The model that agrees with the few experimental points is called an experimentally validated model. Once these models have been validated, we use mathematical interpolation to find the parameters of interest. Sometimes, when measurements are not practical or are impossible extrapolation is implemented but with care. CANBERRA has been extensively using mathematical modeling for the design and calibration of large and sophisticated systems to create and optimize designs that would be prohibitively expensive with only experimental tools. The case studies that will be presented here are primarily performed with MCNP, CANBERRA's MERCURAD/PASCALYS and ISOCS (In Situ Object Counting Software). For benchmarking purposes, both Monte Carlo and ray-tracing based codes are inter-compared to show models consistency and add a degree of reliability to modeling results. (authors)

  14. Effective Mass and g-factor of 2D Electrons in a HgTe Quantum Well from THz Photoresponse

    NASA Astrophysics Data System (ADS)

    Pakmehr, Mehdi; Stier, A. V.; Zhang, H. D.; Bruene, C.; Buhmann, H.; Molenkamp, L.; McCombe, B. D.

    2013-03-01

    There is current interest in HgTe because of its interesting ``inverted'' band structure and large spin-orbit interaction, and because it is a topological insulator under quantum confinement, Well-widths close to that at which the band structure goes from the ``inverted'' to the normal structure are of particular interest. We have used photoresponse excited by several lines from an optically pumped THz laser and magnetotransport measurements to determine the cyclotron effective mass and g-factor of 2D electrons in the gamma_6 conduction band of a high quality HgTe quantum well (ns = 1.55 x 1012 cm-2; 6 nm well) at low temperatures. One of the two samples studied was gated, which allowed density to be varied by over 30%. We find m* =0.039me and g = -18 at the highest density from fits to the PR with the field normal to the plane of the QW, and separately from CR transmission measurements and tilted field experiments. We will also discuss electron spin resonance measurements near filling factors 7 and 9. Supported in part by NSF DMR 1008138

  15. Depth Dependent Background Measurements with the Nuclear Compton Telescope (NCT)

    NASA Astrophysics Data System (ADS)

    Chiu, Jeng-Lun; Chang, H.; Boggs, S. E.; NCT Collaboration

    2012-05-01

    The Nuclear Compton Telescope (NCT) is a balloon-borne soft gamma ray (0.2-10 MeV) telescope designed to study astrophysical sources of nuclear line emission and polarization. The heart of NCT is a compact array of 12 cross-strip germanium detectors (GeDs), providing high spectral resolution ( 0.3-0.9% FWHM at 662 keV for most channels) and capability of tracking each photon interaction with full 3D position resolution to 2 mm3. NCT has flown successfully on two conventional balloon flights to date, and the Crab Nebula was detected at a significance of 4σ in the second flight, which occurred on 2009 May 17 and 18 in Fort Sumner, New Mexico. Here approximately 38 ks of background measurements in the second flight is studied from ground altitude to average float altitude (1.2-40 km). We discuss the expected contributions to the background component through detailed Monte Carlo simulations. Complete depth dependent environmental inputs are introduced, considering cosmic and atmospheric photon distributions, primary cosmic rays (protons), cosmic ray secondaries (protons and neutrons), and activation induced components. Imaging of the 511 keV annihilation line from the background is also attempted.

  16. Nuclear radiation-warning detector that measures impedance

    SciTech Connect

    Savignac, Noel Felix; Gomez, Leo S; Yelton, William Graham; Robinson, Alex; Limmer, Steven

    2013-06-04

    This invention is a nuclear radiation-warning detector that measures impedance of silver-silver halide on an interdigitated electrode to detect light or radiation comprised of alpha particles, beta particles, gamma rays, X rays, and/or neutrons. The detector is comprised of an interdigitated electrode covered by a layer of silver halide. After exposure to alpha particles, beta particles, X rays, gamma rays, neutron radiation, or light, the silver halide is reduced to silver in the presence of a reducing solution. The change from the high electrical resistance (impedance) of silver halide to the low resistance of silver provides the radiation warning that detected radiation levels exceed a predetermined radiation dose threshold.

  17. Experiments and nuclear measurements in search of cold fusion processes

    NASA Astrophysics Data System (ADS)

    Gottesfeld, S.; Anderson, R. E.; Baker, D. A.; Bolton, R. D.; Butterfield, K. B.; Garzon, F. H.; Goulding, C. A.; Johnson, M. W.; Leonard, E. M.; Springer, T. E.; Zawodzinski, T.

    1990-09-01

    This paper reports a collaborative effort of a team which formed at Los Alamos to investigate the announcement that “cold fusion” may be occurring in electrochemical cells using palladium cathodes and platinum anodes in a LiOD electrolyte. Four electrochemical cells were construced and operated for 3-5 weeks under various geometrical and electrical conditions. Nuclear diagnostic measurements included high and low resolution gamma-ray spectroscopy, integral neutron counting with well detectors and banks of3He tubes, and neutron spectroscopy with NE-213 scintillators. For one of the cells, the deuterium loading of the cathode was determined from resistance measurements to be D/Pd⩽ 0.8. No conclusive evidence was found for the production of neutrons or 2.223-MeV gammas above levels consistent with background. The results of the measurements of tritium levels in the cell electrolytes are also reported. Experiments to reproduce the observation of neutrons from high pressure Ti- D 2 gas experiments were also performed with negative results.

  18. In-Pile Thermal Conductivity Measurement Method for Nuclear Fuels

    SciTech Connect

    Joy L. Rempe; Brandon Fox; Heng Ban; Joshua E. Daw; Darrell L. Knudson; Keith G. Condie

    2009-08-01

    Thermophysical properties of advanced nuclear fuels and materials during irradiation must be known prior to their use in existing, advanced, or next generation reactors. Thermal conductivity is one of the most important properties for predicting fuel and material performance. A joint Utah State University (USU) / Idaho National Laboratory (INL) project, which is being conducted with assistance from the Institute for Energy Technology at the Norway Halden Reactor Project, is investigating in-pile fuel thermal conductivity measurement methods. This paper focuses on one of these methods – a multiple thermocouple method. This two-thermocouple method uses a surrogate fuel rod with Joule heating to simulate volumetric heat generation to gain insights about in-pile detection of thermal conductivity. Preliminary results indicated that this method can measure thermal conductivity over a specific temperature range. This paper reports the thermal conductivity values obtained by this technique and compares these values with thermal property data obtained from standard thermal property measurement techniques available at INL’s High Test Temperature Laboratory. Experimental results and material properties data are also compared to finite element analysis results.

  19. Measurement of doses to the extremities of nuclear medicine staff

    NASA Astrophysics Data System (ADS)

    Shousha, Hany A.; Farag, Hamed; Hassan, Ramadan A.

    Medical uses of ionizing radiation now represent>95% of all man-made radiation exposure, and is the largest single radiation source after natural background radiation. Therefore, it is important to quantify the amount of radiation received by occupational individuals to optimize the working conditions for staff, and further, to compare doses in different departments to ensure compatibility with the recommended standards. For some groups working with unsealed sources in nuclear medicine units, the hands are more heavily exposed to ionizing radiation than the rest of the body. A personal dosimetry service runs extensively in Egypt. But doses to extremities have not been measured to a wide extent. The purpose of this study was to investigate the equivalent radiation doses to the fingers for five different nuclear medicine staff occupational groups for which heavy irradiation of the hands was suspected. Finger doses were measured for (1) nuclear medicine physicians, (2) technologists, (3) nurses and (4) physicists. The fifth group contains three technicians handling 131I, while the others handled 99mTc. Each staff member working with the radioactive material wore two thermoluminescent dosimeters (TLDs) during the whole testing period, which lasted from 1 to 4 weeks. Staff performed their work on a regular basis throughout the month, and mean annual doses were calculated for these groups. Results showed that the mean equivalent doses to the fingers of technologist, nurse and physicist groups were 30.24±14.5, 30.37±17.5 and 16.3±7.7 μSv/GBq, respectively. Equivalent doses for the physicians could not be calculated per unit of activity because they did not handle the radiopharmaceuticals directly. Their doses were reported in millisieverts (mSv) that accumulated in one week. Similarly, the dose to the fingers of individuals in Group 5 was estimated to be 126.13±38.2 μSv/GBq. The maximum average finger dose, in this study, was noted in the technologists who handled

  20. Measurement of doses to the extremities of nuclear medicine staff

    NASA Astrophysics Data System (ADS)

    Shousha, Hany A.; Farag, Hamed; Hassan, Ramadan A.

    2010-01-01

    Medical uses of ionizing radiation now represent>95% of all man-made radiation exposure, and is the largest single radiation source after natural background radiation. Therefore, it is important to quantify the amount of radiation received by occupational individuals to optimize the working conditions for staff, and further, to compare doses in different departments to ensure compatibility with the recommended standards. For some groups working with unsealed sources in nuclear medicine units, the hands are more heavily exposed to ionizing radiation than the rest of the body. A personal dosimetry service runs extensively in Egypt. But doses to extremities have not been measured to a wide extent. The purpose of this study was to investigate the equivalent radiation doses to the fingers for five different nuclear medicine staff occupational groups for which heavy irradiation of the hands was suspected. Finger doses were measured for (1) nuclear medicine physicians, (2) technologists, (3) nurses and (4) physicists. The fifth group contains three technicians handling 131I, while the others handled 99mTc. Each staff member working with the radioactive material wore two thermoluminescent dosimeters (TLDs) during the whole testing period, which lasted from 1 to 4 weeks. Staff performed their work on a regular basis throughout the month, and mean annual doses were calculated for these groups. Results showed that the mean equivalent doses to the fingers of technologist, nurse and physicist groups were 30.24±14.5, 30.37±17.5 and 16.3±7.7 μSv/GBq, respectively. Equivalent doses for the physicians could not be calculated per unit of activity because they did not handle the radiopharmaceuticals directly. Their doses were reported in millisieverts (mSv) that accumulated in one week. Similarly, the dose to the fingers of individuals in Group 5 was estimated to be 126.13±38.2 μSv/GBq. The maximum average finger dose, in this study, was noted in the technologists who handled

  1. EPR g factors and defect structures for V4+ and Cr5+ in the rutile-type crystals

    NASA Astrophysics Data System (ADS)

    Wang, Minjie; Zhu, Lianxuan

    2016-08-01

    The g-factor formulas for V4+ and Cr5+ ions in the rutile-type crystals are deduced from Jahn-Teller effect and contributions of the charge transfer levels. The tetragonal distortions ΔR = -0.0045, -0.0045 and -0.0067 nm, and Δθ = 0°, -0.001° and 0°, for GeO2:V4+, TiO2:V4+ and TiO2:Cr5+, respectively. The calculations of the g-factors agree well with the experimental values. The contributions of the charge transfer levels to g factors increase with the increasing valence state. It must be taken into account in the precise calculations of g factors for the high valence state d1 ions in crystals.

  2. Fundamental Symmetries Probed by Precision Nuclear Mass Measurements at ISOLTRAP

    NASA Astrophysics Data System (ADS)

    Bollen, Georg

    2005-04-01

    Mass measurements on rare isotopes can play an important role in testing the nature of fundamental interactions. Precise mass values together with decay data are required for critical tests of the conserved vector current (CVC) hypothesis and the standard model. Substantial progress in Penning trap mass spectrometry has made this technique the best choice for precision measurements on rare isotopes, by providing high accuracy and sensitivity even for short-lived nuclides. The pioneering facility in this field is ISOLTRAP at ISOLDE/CERN. ISOLTRAP is a mass spectrometer capable to determine nuclear binding energies with an uncertainty of 10-8 on nuclides that are produced with yields as low as a few 100 ions/s and at half-lives well below 100 ms. It is used for mass measurements relevant for a better understanding of nuclear structure and the nucleosynthesis of the elements. It is also used for the determination of masses that are important for the test of CVC, the unitary of the Cabibbo-Kobayashi-Maskawa (CKM) matrix, and for putting constrains on the existence of scalars currents. Measurements along this line include ^74Rb (T1/2=65 ms), which is the shortest-lived nuclide studied in a Penning trap. The QEC values of ^74Rb, determined with a precision of 6.10-8, serves as a test of CVC or of related theoretical corrections [1]. Masses of ^32Ar and ^33Ar have been determined with uncertainties of 6.0 . 10-8 and 1.4 . 10-8 [2]. The improved mass for ^32Ar helps to provide a better constraint on scalar contributions to the weak interaction and both argon data serve as the most stringent test of isobaric multiplet mass equation IMME. ^34Ar, another CVC test candidate, has been studied with an uncertainty of 1.1.10-8 (δm = 0.41 keV). Similar precision has been achieved for ^22Mg and neighboring ^21Na and ^22Na [4]. The importance of these results is twofold: First, an Ft value has been obtained for the super-allowed β decay of ^22Mg to further test the CVC hypothesis

  3. Nuclear magnetic resonance and transcutaneous electromagnetic blood flow measurement.

    PubMed

    Battocletti, J H; Halbach, R E; Salles-Cunha, S X; Sances, A

    1983-09-01

    Static and alternating magnetic fields are employed in blood flowmeters using nuclear magnetic resonance (NMR) principles and electromagnetic induction by a moving conductor (TEM). Both techniques require high steady magnetic fields, obtained either from permanent magnets or from electromagnets. A relatively homogeneous magnetic field is needed for NMR, but, though important for calibration, homogeneity is not critical for TEM. NMR is more complex than TEM since it requires radio-frequency and audio-frequency magnetic fields. However, the TEM method requires surface electrodes in contact with the skin, or needle electrodes placed subcutaneously, whereas NMR is contactless. The NMR flowmeter can be calibrated directly, but appropriate and approximate models must be assumed and then solved by computer to quantify blood flow by the TEM flowmeter. Flow in individual vessels is measured a priori in the TEM flowmeter by virtue of the assumed models. To measure flow in individual vessels by NMR, a scanning or ranging method is required, which logically leads to blood flow imaging. The levels of steady, radio-frequency, and audio-frequency magnetic fields used in the two types of flowmeters are low enough so as not to cause any apparent stimulus to human volunteers and patients tested. PMID:6228667

  4. Superconducting quantum spin-Hall systems with giant orbital g-factors

    NASA Astrophysics Data System (ADS)

    Hankiewicz, Ewelina; Reinthaler, Rolf; Tkachov, Grigory

    Topological aspects of superconductivity in quantum spin-Hall systems (QSHSs) such as thin layers of three-dimensional topological insulators (3D Tis) or two-dimensional Tis are in the focus of current research. Here, we describe a novel superconducting quantum spin-Hall effect (quantum spin Hall system in the proximity to the s-wave superconductor and in the orbital in-plane magnetic field), which is protected against elastic backscattering by combined time-reversal and particle-hole symmetry. This effect is characterized by spin-polarized edge states, which can be manipulated in weak magnetic fields due to a giant effective orbital g-factor, allowing the generation of spin currents. The phenomenon provides a novel solution to the outstanding challenge of detecting the spin-polarization of the edge states. Here we propose the detection of the edge polarization in the three-terminal junction using unusual transport properties of superconducting quantum Hall-effect: a non-monotonic excess current and a zero-bias conductance splitting. We thank for the financial support the German Science Foundation (DFG), Grants No HA 5893/4-1 within SPP 1666, HA5893/5-2 within FOR1162 and TK60/1-1 (G.T.), as well the ENB graduate school ``Topological insulators''.

  5. The G-factor as a tool to learn more about bone structure and function.

    PubMed

    Zerath, E

    1999-07-01

    In normal life on earth, the locomotor system is exposed to two types of stimulation: gravity (passive stimulation) and motion (active stimulation). Both permanently combine, and the interactions between locomotion and gravity induce an overall recruitment which is repeated daily and maintains the bone tissue structure within the range of constraints to which it is adapted. This range is one of the basic hypotheses underlying the mechanical concepts of bone structure control, and it has been considered as logical to assume that weightlessness of spaceflight should produce bone loss since astronauts are outside of the terrestrial gravitational field of forces, no longer relying on muscular work to change positions or move. But, thirty years after the first changes in phospho-calcium metabolism were observed in astronauts after spaceflight, current knowledge does not provide a full understanding of this pathogeny, and prove the G-factor is now considered as an essential component of the experimental tools available to study bone physiology. The study of the physiology of bone tissue usually consists in the investigation of its two fundamental roles, i.e. reservoir of inorganic elements (calcium, phosphorus, magnesium) and mechanical support for soft tissues. Together with the combined action of muscles, tendons, and ligaments, this support permits motion and locomotion. These two functions rely on a sophisticated bone tissue architecture, and on the adaptability of this structure, with modeling and remodeling processes, themselves associated with the coupled activity of specialized bone cell populations. PMID:11543035

  6. g-factor and spin-parity assignments of excited states in the N=83 isotones {sup 135}Te, {sup 136}I, {sup 137}Xe, and {sup 138}Cs

    SciTech Connect

    Liu, S. H.; Hamilton, J. H.; Ramayya, A. V.; Hwang, J. K.; Covello, A.; Itaco, N.; Gargano, A.; Stone, N. J.; Daniel, A. V.; Luo, Y. X.; Rasmussen, J. O.; Ter-Akopian, G. M.; Zhu, S. J.; Ma, W. C.

    2010-01-15

    The g factor of the 15/2{sup -} state in {sup 137}Xe was measured for the first time by using a newly developed technique for measuring angular correlations with Gammasphere. Spins and parities were assigned to several levels in the N=83 isotones {sup 135}Te, {sup 136}I, {sup 137}Xe, and {sup 138}Cs. The calculated g factor in the shell-model frame is in good agreement with the measured one in the present work. Shell-model calculations also support our spin-parity assignments.

  7. Review of nuclear data improvement needs for nuclear radiation measurement techniques used at the CEA experimental reactor facilities

    NASA Astrophysics Data System (ADS)

    Destouches, Christophe

    2016-03-01

    The constant improvement of the neutron and gamma calculation codes used in experimental nuclear reactors goes hand in hand with that of the associated nuclear data libraries. The validation of these calculation schemes always requires the confrontation with integral experiments performed in experimental reactors to be completed. Nuclear data of interest, straight as cross sections, or elaborated ones such as reactivity, are always derived from a reaction rate measurement which is the only measurable parameter in a nuclear sensor. So, in order to derive physical parameters from the electric signal of the sensor, one needs specific nuclear data libraries. This paper presents successively the main features of the measurement techniques used in the CEA experimental reactor facilities for the on-line and offline neutron/gamma flux characterizations: reactor dosimetry, neutron flux measurements with miniature fission chambers and Self Power Neutron Detector (SPND) and gamma flux measurements with chamber ionization and TLD. For each technique, the nuclear data necessary for their interpretation will be presented, the main identified needs for improvement identified and an analysis of their impact on the quality of the measurement. Finally, a synthesis of the study will be done.

  8. Nuclear Resonance Fluorescence to Measure Plutonium Mass in Spent Nuclear Fuel

    SciTech Connect

    Ludewigt, Bernhard A; Quiter, Brian J.; Ambers, Scott D.

    2011-01-14

    The Next Generation Safeguard Initiative (NGSI) of the U.S Department of Energy is supporting a multi-lab/university collaboration to quantify the plutonium (Pu) mass in spent nuclear fuel (SNF) assemblies and to detect the diversion of pins with non-destructive assay (NDA) methods. The following 14 NDA techniques are being studied: Delayed Neutrons, Differential Die-Away, Differential Die-Away Self-Interrogation, Lead Slowing Down Spectrometer, Neutron Multiplicity, Passive Neutron Albedo Reactivity, Total Neutron (Gross Neutron), X-Ray Fluorescence, {sup 252}Cf Interrogation with Prompt Neutron Detection, Delayed Gamma, Nuclear Resonance Fluorescence, Passive Prompt Gamma, Self-integration Neutron Resonance Densitometry, and Neutron Resonance Transmission Analysis. Understanding and maturity of the techniques vary greatly, ranging from decades old, well-understood methods to new approaches. Nuclear Resonance Fluorescence (NRF) is a technique that had not previously been studied for SNF assay or similar applications. Since NRF generates isotope-specific signals, the promise and appeal of the technique lies in its potential to directly measure the amount of a specific isotope in an SNF assay target. The objectives of this study were to design and model suitable NRF measurement methods, to quantify capabilities and corresponding instrumentation requirements, and to evaluate prospects and the potential of NRF for SNF assay. The main challenge of the technique is to achieve the sensitivity and precision, i.e., to accumulate sufficient counting statistics, required for quantifying the mass of Pu isotopes in SNF assemblies. Systematic errors, considered a lesser problem for a direct measurement and only briefly discussed in this report, need to be evaluated for specific instrument designs in the future. Also, since the technical capability of using NRF to measure Pu in SNF has not been established, this report does not directly address issues such as cost, size

  9. Potential cooperative measures on nuclear issues in Asia

    SciTech Connect

    Olsen, J.

    1997-08-01

    Cooperation on nuclear issues is receiving increased attention in Asia. In Northeast Asia, where the nuclear industry is well-developed, cooperation in the back end of the nuclear fuel cycle could help deal with issues such as disposition of spent fuel and long term storage options. In Southeast Asia, where countries are just beginning to introduce nuclear energy, cooperation would be useful in developing standards for the nuclear industry. Throughout Asia, nuclear research and power activities can raise concerns about safety, environmental pollution and proliferation. The sharing of relevant information, i.e. cooperative monitoring, will be essential to addressing these issues. In fact, a number of regional interactions on nuclear issues are already occurring. These range from training exchanges sponsored by the more advanced states to participation in environmental monitoring of the East Sea (Sea of Japan). Several states are considering sharing information from their nuclear facilities; some exchanges of radiation data are already in place. The KEDO reactor project will involve close working relations between the nuclear experts of South Korea, North Korea, Japan, and the US. Areas for further regional cooperation are discussed.

  10. Exchange enhancement of the electron g-factor in a two-dimensional semimetal in HgTe quantum wells

    SciTech Connect

    Bovkun, L. S. Krishtopenko, S. S.; Zholudev, M. S.; Ikonnikov, A. V.; Spirin, K. E.; Dvoretsky, S. A.; Mikhailov, N. N.; Teppe, F.; Knap, W.; Gavrilenko, V. I.

    2015-12-15

    The exchange enhancement of the electron g-factor in perpendicular magnetic fields to 12 T in HgTe/CdHgTe quantum wells 20 nm wide with a semimetal band structure is studied. The electron effective mass and g-factor at the Fermi level are determined by analyzing the temperature dependence of the amplitude of Shubnikov–de Haas oscillation in weak fields and near odd Landau-level filling factors ν ≤ 9. The experimental values are compared with theoretical calculations performed in the one-electron approximation using the eight-band kp Hamiltonian. The found dependence of g-factor enhancement on the electron concentration is explained by changes in the contributions of hole- and electron-like states to exchange corrections to the Landau-level energies in the conduction band.

  11. Dependence of Berry's phase for atom on a sign of the g factor in the rotating magnetic field

    SciTech Connect

    Morinaga, Atsuo; Aoki, Takatoshi; Yasuhara, Makoto

    2005-05-15

    Berry's phase of the atom in the state with a positive or negative g factor for partial cycles of a rotating magnetic field was determined free from the dynamical phase shift using a time-domain atom interferometer. The experimental phase shift is in good agreement with the prediction of Berry's phase for partial cycles. It was found that the sense of Berry's phase depends on the sign of the magnetic quantum number, the sense of the rotating magnetic field, and the sign of the g factor of the state.

  12. Δg: The new aromaticity index based on g-factor calculation applied for polycyclic benzene rings

    NASA Astrophysics Data System (ADS)

    Ucun, Fatih; Tokatlı, Ahmet

    2015-02-01

    In this work, the aromaticity of polycyclic benzene rings was evaluated by the calculation of g-factor for a hydrogen placed perpendicularly at geometrical center of related ring plane at a distance of 1.2 Å. The results have compared with the other commonly used aromatic indices, such as HOMA, NICSs, PDI, FLU, MCI, CTED and, generally been found to be in agreement with them. So, it was proposed that the calculation of the average g-factor as Δg could be applied to study the aromaticity of polycyclic benzene rings without any restriction in the number of benzene rings as a new magnetic-based aromaticity index.

  13. Uncertainties for criticality-safety benchmarks and consequences for nuclear data measurements

    NASA Astrophysics Data System (ADS)

    Rochman, D.; Koning, A. J.; van der Marck, S. C.

    2009-10-01

    We have developed a new method to propagate the uncertainties of fundamental nuclear physics models and parameters used in nuclear data evaluation to the design and performance of future nuclear energy systems. Using Monte Carlo simulation, it is for the first time possible to couple these two fields at the extremes of nuclear science without any loss of information in between. With the help of a large database of nuclear reaction measurements, we have determined the uncertainties of theoretical nuclear reaction models such as the optical, compound nucleus, pre-equilibrium and fission models. A similar assessment is done for the parameters that describe the resolved resonance range. We are now able to quantify the required quality of theoretical nuclear reaction models and measurements directly from the reactor design requirements. Examples will be presented for actinides using criticality-safety benchmarks with feedback on experimental requirements.

  14. G factor of the 2/sub 1//sup +/ state in /sup 140/Ba and /sup 142/Ba

    SciTech Connect

    Pauling, L.

    1987-06-01

    A simple calculation on the basis of the revolving cluster model leads to the value 0.495 for the g factor of /sub //sub <1/ /sub 56//sup 42/Ba/sub 86/, in agreement with the experimental value 0.48 +- 0.14. The same value is predicted for /sup 140/Ba.

  15. Measurement of Nuclear Dependence in Inclusive Charged Current Neutrino Scattering

    SciTech Connect

    Tice, Brian George

    2014-01-01

    Neutrino experiments use heavy nuclei (C, Fe, Pb) to achieve necessary statistics. However, the use of heavy nuclei exposes these experiments to the nuclear dependence of neutrino-nucleus cross sections, which are poorly known and difficult to model. This dissertation presents an analysis of the nuclear dependence of inclusive chargedcurrent neutrino scattering using events in carbon, iron, lead, and scintillator targets of the MINERvA detector. MINERvA (Main INjector ExpeRiment for -A) is a few-GeV neutrinonucleus scattering experiment at Fermilab.

  16. Tuning the electrically evaluated electron Landé g factor in GaAs quantum dots and quantum wells of different well widths

    NASA Astrophysics Data System (ADS)

    Allison, G.; Fujita, T.; Morimoto, K.; Teraoka, S.; Larsson, M.; Kiyama, H.; Oiwa, A.; Haffouz, S.; Austing, D. G.; Ludwig, A.; Wieck, A. D.; Tarucha, S.

    2014-12-01

    We evaluate the Landé g factor of electrons in quantum dots (QDs) fabricated from GaAs quantum well (QW) structures of different well width. We first determine the Landé electron g factor of the QWs through resistive detection of electron spin resonance and compare it to the enhanced electron g factor determined from analysis of the magnetotransport. Next, we form laterally defined quantum dots using these quantum wells and extract the electron g factor from analysis of the cotunneling and Kondo effect within the quantum dots. We conclude that the Landé electron g factor of the quantum dot is primarily governed by the electron g factor of the quantum well suggesting that well width is an ideal design parameter for g -factor engineering QDs.

  17. Synergistic smart fuel for in-pile nuclear reactor measurements

    SciTech Connect

    Smith, J.A.; Kotter, D.K.; Ali, R.A.; Garrett, S.L.

    2013-07-01

    The thermo-acoustic fuel rod sensor developed in this research has demonstrated a novel technique for monitoring the temperature within the core of a nuclear reactor or the temperature of the surrounding heat-transfer fluid. It uses the heat from the nuclear fuel to generate sustained acoustic oscillations whose frequency will be indicative of the temperature. Converting a nuclear fuel rod into this type of thermo-acoustic sensor simply requires the insertion of a porous material (stack). This sensor has demonstrated a synergy with the elevated temperatures that exist within the nuclear reactor using materials that have only minimal susceptibility to high-energy particle fluxes. When the sensor is in operation, the sound waves radiated from the fuel rod resonator will propagate through the surrounding cooling fluid. The frequency of these oscillations is directly correlated with an effective temperature within the fuel rod resonator. This device is self-powered and is operational even in case of total loss of power of the reactor.

  18. Synergistic Smart Fuel For In-pile Nuclear Reactor Measurements

    SciTech Connect

    James A. Smith; Dale K. Kotter; Randall A. Ali; Steven L . Garrett

    2013-10-01

    In March 2011, an earthquake of magnitude 9.0 on the Richter scale struck Japan with its epicenter on the northeast coast, near the Tohoku region. In addition to the immense physical destruction and casualties across the country, several nuclear power plants (NPP) were affected. It was the Fukushima Daiichi NPP that experienced the most severe and irreversible damage. The earthquake brought the reactors at Fukushima to an automatic shutdown and because the power transmission lines were damaged, emergency diesel generators (EDGs) were activated to ensure that there was continued cooling of the reactors and spent fuel pools. The situation was being successfully managed until the tsunami hit about forty-five minutes later with a maximum wave height of approximately 15 m. The influx of water submerged the EDGs, the electrical switchgear, and dc batteries, resulting in the total loss of power to the reactors.2 At this point, the situation became critical. There was a loss of the sensors and instrumentation within the reactor that could have provided valuable information to guide the operators to make informed decisions and avoid the unfortunate events that followed. In the light of these events, we have developed and tested a potential self-powered thermoacoustic system, which will have the ability to serve as a temperature sensor and can transmit data independently of electronic networks. Such a device is synergistic with the harsh environment of the nuclear reactor as it utilizes the heat from the nuclear fuel to provide the input power.

  19. 78 FR 55765 - Compensatory and Alternative Regulatory Measures for Nuclear Power Plant Fire Protection (CARMEN...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-11

    ... (78 FR 45573) a request for public comment on NUREG/CR-7135, ``Compensatory and Alternative Regulatory... COMMISSION Compensatory and Alternative Regulatory Measures for Nuclear Power Plant Fire Protection (CARMEN-FIRE) AGENCY: Nuclear Regulatory Commission. ACTION: Draft NUREG/CR, reopening of comment...

  20. Computing the Kirkwood g-Factor by Combining Constant Maxwell Electric Field and Electric Displacement Simulations: Application to the Dielectric Constant of Liquid Water.

    PubMed

    Zhang, Chao; Hutter, Jürg; Sprik, Michiel

    2016-07-21

    In his classic 1939 paper, Kirkwood linked the macroscopic dielectric constant of polar liquids to the local orientational order as measured by the g-factor (later named after him) and suggested that the corresponding dielectric constant at short-range is effectively equal to the macroscopic value just after "a distance of molecular magnitude" [ Kirkwood, J. Chem. Phys., 1939, 7, 911 ]. Here, we show a simple approach to extract the short-ranged Kirkwood g-factor from molecular dynamics (MD) simulation by superposing the outcomes of constant electric field E and constant electric displacement D simulations [ Zhang and Sprik, Phys. Rev. B: Condens. Matter Mater. Phys., 2016, 93, 144201 ]. Rather than from the notoriously slow fluctuations of the dipole moment of the full MD cell, the dielectric constant can now be estimated from dipole fluctuations at short-range, accelerating the convergence. Exploiting this feature, we computed the bulk dielectric constant of liquid water modeled in the generalized gradient approximation (PBE) to density functional theory and found it to be at least 40% larger than the experimental value. PMID:27352038

  1. Calculation of EPR Parameters g Factors for Ce3+ Ion in YBa2Cu3O6+x Superconductor

    NASA Astrophysics Data System (ADS)

    Dong, Hui-Ning; Du, Hui-Ping; Duan, Chang-Kui; Luo, Xiao-Bing

    The perturbation formulae of EPR parameters g factors gx, gy and gz for the lowest Kramers doublet of 4f1 ion in orthorhombic symmetry are established. In these formulae, the contributions of the covalency effects, the admixture between J=7/2 and J=5/2 states as well as the second-order perturbation (which is not considered in the previous works) via crystal-field and orbital angular momentum interactions are all included. According to these formulae, and by using the superposition model, the g-factors gx, gy and gz for Ce3+ center in YBa2Cu3O6+x superconductor are calculated. The results are discussed.

  2. Confirmatory Factor Analysis of Project Spectrum Activities. A Second-Order "g" Factor or Multiple Intelligences?

    ERIC Educational Resources Information Center

    Castejon, Juan L.; Perez, Antonio M.; Gilar, Raquel

    2010-01-01

    This paper compares different theoretical models of the structure of intelligence, based on the analysis of data obtained in a series of measured abilities corresponding to the Spectrum assessment activities (Gardner, Feldman & Krechevsky, 1998) in a sample of 393 children enrolled in kindergarten and first grade. The data were analyzed using…

  3. Finding the "g"-Factor in Brain Structure Using the Method of Correlated Vectors

    ERIC Educational Resources Information Center

    Colom, Roberto; Jung, Rex E.; Haier, Richard J.

    2006-01-01

    It is unclear whether brain mechanisms underlying human intelligence are distributed throughout the brain or mainly concentrated in the frontal lobes. Data are inconsistent possibly due, at least in part, to the different ways the construct of intelligence is measured. Here we apply the method of correlated vectors to determine how the general…

  4. Wave Function Mixing and g-Factors in Narrow Gap Ferromagnetic III-V Dilute Magnetic Semiconductors

    NASA Astrophysics Data System (ADS)

    Sun, Y.; Sanders, G. D.; Stanton, C. J.

    2002-03-01

    We present a theory for wave-function mixing and g-factors in ferromagnetic p-doped narrow gap In_1-xMn_xAs dilute magnetic semiconductor alloys in an ultrahigh external magnetic field, B. We generalize an 8 band Pidgeon-Brown model to include (i) the wavevector, k, dependence of the electronic states along B, (ii) s-d and p-d exchange interactions with localized Mn d-electrons, and (iii) finite magnetic moment in the ferromagnetic state. The complex valence band structure at finite k plays an important role in the cyclotron resonance spectra. We look at the band-mixing and spin-dependence of the wave functions as a function of the wavevector, magnetic field (0-100T), temperature (4 K to 290 K), and Mn concentration (0 to 12 %). From this, we can extract magnetic field dependent g-factors. The sensitivity of the band mixing and g-factors to the s-d and p-d exchange interactions is also investigated. Finally, we look at the effect of band-mixing on optical properties such as the polarization dependence of the absorption and luminescence.

  5. Calculation of the g Factors and Local Angular Distortions for ZnO:Cu2+ Nanocrystals With Various Copper Concentrations

    NASA Astrophysics Data System (ADS)

    Li, G.-L.; Wu, S.-Y.; Hu, X.-F.; Teng, B.-H.; Wu, M.-H.

    2016-07-01

    Based on the perturbation treatments for a tetragonally distorted tetrahedral 3d 9 cluster, the g factors and local angular distortions are calculated for ZnO:Cu2+ nanocrystals with various Cu2+ concentrations in different systems I and II under dissimilar experimental conditions. Because of the dynamic Jahn-Teller effect, the bond angles θ between the four equivalent Cu2+-O2- bonds and the C4 axis are about 1.5o larger than that (θ0 ≈ 54.736o) of an ideal tetrahedron. Consequently, the original slightly trigonally distorted oxygen tetrahedron of the host Zn2+ site is transformed into a tetragonally compressed one. The isotropy of g factors may be attributed to the appropriate angular distortions Δθ = θ - θ0 due to the dynamic Jahn-Teller effect. The slightly increasing (or decreasing) g factors with concentration x can be illustrated as the delicate increases (or decreases) of the angular distortions (Δθ) and the covalency factors (N) for system I (or II), respectively, under almost equivalent crystal-fi eld strengths (Dq).

  6. Measurement of the nuclear energy loss under channeling

    NASA Astrophysics Data System (ADS)

    Winter, H.; Mertens, A.

    2001-07-01

    Neutral Ne atoms with keV energies are scattered under channeling conditions, i.e. at a glancing angle of incidence, from a LiF(001) surface. By means of a time-of-flight method with a pulsed neutral beam we record energy distributions for scattered projectiles. For this specific system the small energy transferred to the crystal lattice ("nuclear energy loss") during channeling via binary collisions with large impact parameters dominates the dissipation of projectile energy. All other excitations of the solid can be brought to a negligible level.

  7. Rapid flow cytometric measurement of protein inclusions and nuclear trafficking.

    PubMed

    Whiten, D R; San Gil, R; McAlary, L; Yerbury, J J; Ecroyd, H; Wilson, M R

    2016-01-01

    Proteinaceous cytoplasmic inclusions are an indicator of dysfunction in normal cellular proteostasis and a hallmark of many neurodegenerative diseases. We describe a simple and rapid new flow cytometry-based method to enumerate, characterise and, if desired, physically recover protein inclusions from cells. This technique can analyse and resolve a broad variety of inclusions differing in both size and protein composition, making it applicable to essentially any model of intracellular protein aggregation. The method also allows rapid quantification of the nuclear trafficking of fluorescently labelled molecules. PMID:27516358

  8. Rapid flow cytometric measurement of protein inclusions and nuclear trafficking

    PubMed Central

    Whiten, D. R.; San Gil, R.; McAlary, L.; Yerbury, J. J.; Ecroyd, H.; Wilson, M. R.

    2016-01-01

    Proteinaceous cytoplasmic inclusions are an indicator of dysfunction in normal cellular proteostasis and a hallmark of many neurodegenerative diseases. We describe a simple and rapid new flow cytometry-based method to enumerate, characterise and, if desired, physically recover protein inclusions from cells. This technique can analyse and resolve a broad variety of inclusions differing in both size and protein composition, making it applicable to essentially any model of intracellular protein aggregation. The method also allows rapid quantification of the nuclear trafficking of fluorescently labelled molecules. PMID:27516358

  9. Hydrogen release from irradiated elastomers measured by Nuclear Reaction Analysis

    NASA Astrophysics Data System (ADS)

    Jagielski, J.; Ostaszewska, U.; Bielinski, D. M.; Grambole, D.; Romaniec, M.; Jozwik, I.; Kozinski, R.; Kosinska, A.

    2016-03-01

    Ion irradiation appears as an interesting method of modification of elastomers, especially friction and wear properties. Main structural effect caused by heavy ions is a massive loss of hydrogen from the surface layer leading to its smoothening and shrinking. The paper presents the results of hydrogen release from various elastomers upon irradiation with H+, He+ and Ar+ studied by using Nuclear Reaction Analysis (NRA) method. The analysis of the experimental data indicates that the hydrogen release is controlled by inelastic collisions between ions and target electrons. The last part of the study was focused on preliminary analysis of mechanical properties of irradiated rubbers.

  10. Nuclear-resonance magnetometer with flowing liquid for superstrong inhomogeneous fields measuring

    NASA Astrophysics Data System (ADS)

    Davydov, V. V.; Dudkin, V. I.; Vologdin, V. A.

    2016-03-01

    Multichannel nuclear-resonance magnetometer for remote monitoring of induction and heterogeneity of a magnetic field in different areas inside and near a charged particle accelerator is considered. The maximal distance between the nuclear magnetic resonance signal detector and the magnetometer is 50 m. Measurement error is 0.5%, sensitivity of the magnetometer is 10-10 T/Hz1/2, measurement time of the magnetic field parameters in 24 control points is no more than 4 minutes.

  11. Observation of Optical Chemical Shift by Precision Nuclear Spin Optical Rotation Measurements and Calculations.

    PubMed

    Shi, Junhui; Ikäläinen, Suvi; Vaara, Juha; Romalis, Michael V

    2013-02-01

    Nuclear spin optical rotation (NSOR) is a recently developed technique for detection of nuclear magnetic resonance via rotation of light polarization, instead of the usual long-range magnetic fields. NSOR signals depend on hyperfine interactions with virtual optical excitations, giving new information about the nuclear chemical environment. We use a multipass optical cell to perform the first precision measurements of NSOR signals for a range of organic liquids and find clear distinction between proton signals for different compounds, in agreement with our earlier theoretical predictions. Detailed first-principles quantum mechanical NSOR calculations are found to be in agreement with the measurements. PMID:26281737

  12. Application of American National Standards of calibration techniques of bulk measurements for nuclear materials control

    SciTech Connect

    Doher, L. W.; Gerald, K. B.

    1980-01-01

    In 1975 Subcommittee ANSI-INMM-8, Calibration Techniques for Nuclear Material Control under the guidance of the American National Standards Institute Committee N15 and sponsored by the Institute of Nuclear Materials Management, published four standards for calibration of bulk measurement of nuclear materials. The calibration techniques include those for mass, volume, nondestructive assay, and plutonium calorimetry measurements. Since that time, calibration and research personnel of the Rocky Flats Plant and workers at other facilities have applied the direction and guidance of these standards. Results of the applications are reported and th value of each standard discussed. Examples are included together with certain shortcomings and future revision plans.

  13. Projective measurement of a single nuclear spin qubit by using two-mode cavity QED.

    PubMed

    Eto, Yujiro; Noguchi, Atsushi; Zhang, Peng; Ueda, Masahito; Kozuma, Mikio

    2011-04-22

    We report the implementation of projective measurement on a single 1/2 nuclear spin of the (171)Yb atom by measuring the polarization of cavity-enhanced fluorescence. To obtain cavity-enhanced fluorescence having a nuclear-spin-dependent polarization, we construct a two-mode cavity QED system, in which two cyclic transitions are independently coupled to each of the orthogonally polarized cavity modes, by manipulating the energy level of (171)Yb. This system can associate the nuclear spin degrees of freedom with the polarization of photons, which will facilitate the development of hybrid quantum systems. PMID:21599343

  14. Passive Measurement of Organic-Scintillator Neutron Signatures for Nuclear Safeguards Applications

    SciTech Connect

    Jennfier L. Dolan; Eric C. Miller; Alexis C. Kaplan; Andreas Enqvist; Marek Flaska; Alice Tomanin; Paolo Peerani; David L. Chichester; Sara A. Pozzi

    2012-10-01

    At nuclear facilities, domestically and internationally, most measurement systems used for nuclear materials’ control and accountability rely on He-3 detectors. Due to resource shortages, alternatives to He-3 systems are needed. This paper presents preliminary simulation and experimental efforts to develop a fast-neutron-multiplicity counter based on liquid organic scintillators. This mission also provides the opportunity to broaden the capabilities of such safeguards measurement systems to improve current neutron-multiplicity techniques and expand the scope to encompass advanced nuclear fuels.

  15. C+C Fusion Cross Sections Measurements for Nuclear Astrophysics

    DOE PAGESBeta

    Almaraz-Calderon, S.; Carnelli, P. F. F.; Rehm, K. E.; Albers, M.; Alcorta, M.; Bertone, P. F.; Digiovine, B.; Esbensen, H.; Fernandez Niello, J. O.; Henderson, D.; et al

    2015-06-02

    Total fusion cross section of carbon isotopes were obtained using the newly developed MUSIC detector. MUSIC is a highly efficient, active target-detector system designed to measure fusion excitation functions with radioactive beams. The present measurements are relevant for understanding x-ray superbursts. The results of the first MUSIC campaign as well as the astrophysical implications are presented in this work.

  16. C+C Fusion Cross Sections Measurements for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Almaraz-Calderon, S.; Carnelli, P. F. F.; Rehm, K. E.; Albers, M.; Alcorta, M.; Bertone, P. F.; Digiovine, B.; Esbensen, H.; Fernandez Niello, J. O.; Henderson, D.; Jiang, C. L.; Lai, J.; Marley, S. T.; Nusair, O.; Palchan-Hazan, T.; Pardo, R. C.; Paul, M.; Ugalde, C.

    2015-06-01

    Total fusion cross section of carbon isotopes were obtained using the newly developed MUSIC detector. MUSIC is a highly efficient, active target-detector system designed to measure fusion excitation functions with radioactive beams. The present measurements are relevant for understanding x-ray superbursts. The results of the first MUSIC campaign as well as the astrophysical implications are presented in this work.

  17. Very high temperature measurements: Application to nuclear reactor safety tests

    NASA Astrophysics Data System (ADS)

    Parga, Clemente Jose

    This PhD dissertation focuses on the improvement of very high temperature thermometry (1100ºC to 2480ºC), with special emphasis on the application to the field of nuclear reactor safety and severe accident research. Two main projects were undertaken to achieve this objective: -The development, testing and transposition of high-temperature fixed point (HTFP) metal-carbon eutectic cells, from metrology laboratory precision (+/-0.001ºC) to applied research with a reasonable degradation of uncertainties (+/-3-5ºC). -The corrosion study and metallurgical characterization of Type-C thermocouple (service temp. 2300ºC) prospective sheath material was undertaken to extend the survivability of TCs used for molten metallic/oxide corium thermometry (below 2000ºC).

  18. USCEA/NIST measurement assurance programs for the radiopharmaceutical and nuclear power industries

    SciTech Connect

    Golas, D.B.

    1993-12-31

    In cooperation with the U.S. Council for Energy Awareness (USCEA), the National Institute of Standards and Technology (NIST) supervises and administers two measurement assurance programs for radioactivity measurement traceability. One, in existence since the mid 1970s, provides traceability to suppliers of radiochemicals and radiopharmaceuticals, dose calibrators, and nuclear pharmacy services. The second program, begun in 1987, provides traceability to the nuclear power industry for utilities, source suppliers, and service laboratories. Each program is described, and the results of measurements of samples of known, but undisclosed activity, prepared at NIST and measured by the participants are presented.

  19. Neutron measurements in Spanish nuclear power plants with a Bonner sphere spectrometer system.

    PubMed

    Fernández, F; Domingo, C; Amgarou, K; Bouassoule, T; García, M J

    2007-01-01

    Neutron spectrometric measurements with an active Bonner Sphere System (BSS) allowed us to determine the reference dosimeter values in Ascó I and II and Cofrentes (PWR, BWR) Spanish nuclear power plants. Under a request from the Spanish National Nuclear Safety Council, the UAB group was in charge of characterising the neutron fields at several measurement points (a total of 10) inside the containment building of these nuclear installations using an active BSS and a home-made MITOM unfolding code. The measurement results in the three installations confirm the presence of low-energy neutron components in almost all selected points. This developed BSS can be considered as a reference system in neutron radiation protection when defining the corresponding protocols for a correct personal dosimetry in nuclear power plant installations. PMID:17525063

  20. Studies of the g factors of the ground 4A2 and the first excited 2E state of Cr 3+ ions in emerald

    NASA Astrophysics Data System (ADS)

    Wei, Qun; Guo, Li-Xin; Yang, Zi-Yuan; Wei, Bing

    2011-09-01

    By using complete diagonalization method, the zero-field splitting and g factors of the ground 4A2 and the first excited 2E states of Cr 3+ ions in emerald are calculated. The theoretical results are in good agreement with the experimental data. The dependencies of the g factors on the crystal field parameters, including Dq, v, and v', have been studied. It is shown that, the g factors of the ground state varied with the crystal field parameters approximately in a linear way, but the g factors of the first excited state varied nonlinearly with these parameters.

  1. g-Factors of Isomeric States in the Neutron-Rich Nuclei

    SciTech Connect

    Georgiev, G.; Neyens, G.; Hass, M.; Balabanski, Dimiter Loukanov; Bingham, Carrol R; Borcea, C.; Coulier, N.; Coussenment, R.; Daugas, J. M.; De France, Gilles M; Gorska, M.; Grawe, Hubert H; Grzywacz, Robert Kazimierz; Lewitowicz, Marek; Mach, Henryk A; Matea, I.; de Oliveira Santos, F.; Page, R. D.; Pfutzner, Marek; Penionzhkevich, Yu. E.; Podolyak, Zsolt F; Regan, Patrick H; Rykaczewski, Krzysztof Piotr; Sawicka, M.; Smirnova, N. A.; Sobolev, Yu.; Stanoiu, M.; Teughels, S.; Vyvey, K.

    2004-02-01

    We report the results from the first experiment to measure gyromagnetic factors of {micro}s isomers in neutron-rich nuclei produced by intermediate-energy projectile-fragmentation reactions. The Time Dependent Perturbed Angular Distribution (TDPAD) method was applied in combination with the heavy-ion-gamma correlation technique. The nuclides in the vicinity of {sup 68}Ni were produced and spin-oriented following the fragmentation of a {sup 76}Ge, 61.4 MeV/ u beam at GANIL. The results obtained, |g|({sup 69 m}Cu) = 0.225(25) and |g|({sup 67 m}Ni) = 0.125(6) provide another indication of the importance of proton excitation across the Z = 28 shell gap for the description of these states.

  2. Magnetoresistivity and acoustoelectronic effects in a tilted magnetic field in p-Si/SiGe/Si structures with an anisotropic g factor

    SciTech Connect

    Drichko, I. L. Smirnov, I. Yu.; Suslov, A. V.; Mironov, O. A.; Leadley, D. R.

    2010-09-15

    Magnetoresistivity {rho}{sub xx} and {rho}{sub xy} and the acoustoelectronic effects are measured in p-Si/SiGe/Si with an impurity concentration p = 1.99 x 10{sup 11} cm{sup -2} in the temperature range 0.3-2.0 K and an tilted magnetic field up to 18 T. The dependence of the effective g factor on the angle of magnetic field tilt {theta} to the normal to the plane of a two-dimensional p-Si/SiGe/Si channel is determined. A first-order ferromagnet-paramagnet phase transition is observed in the magnetic fields corresponding to a filling factor {nu} = 2 at {theta} {approx} 59{sup o}-60{sup o}.

  3. Assessment of Nuclear Fuels using Radiographic Thickness Measurement Method

    SciTech Connect

    Muhammad Abir; Fahima Islam; Hyoung Koo Lee; Daniel Wachs

    2014-11-01

    The Convert branch of the National Nuclear Security Administration (NNSA) Global Threat Reduction Initiative (GTRI) focuses on the development of high uranium density fuels for research and test reactors for nonproliferation. This fuel is aimed to convert low density high enriched uranium (HEU) based fuel to high density low enriched uranium (LEU) based fuel for high performance research reactors (HPRR). There are five U.S. reactors that fall under the HPRR category, including: the Massachusetts Institute of Technology Reactor (MITR), the National Bureau of Standards Reactor (NBSR), the Missouri University Research Reactor (UMRR), the Advanced Test Reactor (ATR), and the High Flux Isotope Reactor (HFIR). U-Mo alloy fuel phase in the form of either monolithic or dispersion foil type fuels, such as ATR Full-size In center flux trap Position (AFIP) and Reduced Enrichment for Research and Test Reactor (RERTR), are being designed for this purpose. The fabrication process1 of RERTR is susceptible to introducing a variety of fuel defects. A dependable quality control method is required during fabrication of RERTR miniplates to maintain the allowable design tolerances, therefore evaluating and analytically verifying the fabricated miniplates for maintaining quality standards as well as safety. The purpose of this work is to analyze the thickness of the fabricated RERTR-12 miniplates using non-destructive technique to meet the fuel plate specification for RERTR fuel to be used in the ATR.

  4. Theoretical investigations of EPR g factors for Ce3+ ion at monoclinic Cs site in YAlO3 crystal

    NASA Astrophysics Data System (ADS)

    Liu, Hong-Gang; Zheng, Wen-Chen

    2015-01-01

    Three EPR principal g values (gx, gy and gz) for monoclinic (Cs) Ce3+ center in YAlO3 crystal are calculated by the complete diagonalization (of energy matrix) method (CDM) based on the superposition model (SPM) analysis. The calculated g factors are more reasonably closer to experimental results reported by Asatryan et al. (2002) than their same work in 1997. The reliability of fitted crystal-field parameters of YAP:Ce3+ crystal is also analyzed. In SPM calculations, the seeming abnormal negative power-law exponent t6 is found to be actually reasonable and its underlying cause may be explained by future ab initio studies.

  5. Uncertainty minimization in NMR measurements of dynamic nuclear polarization of a proton target for nuclear physics experiments

    SciTech Connect

    Keller, Dustin M.

    2013-11-01

    A comprehensive investigation into the measurement uncertainty in polarization produced by Dynamic Nuclear Polarization is outlined. The polarization data taken during Jefferson Lab experiment E08-007 is used to obtain error estimates and to develop an algorithm to minimize uncertainty of the measurement of polarization in irradiated View the ^14NH_3 targets, which is readily applied to other materials. The target polarization and corresponding uncertainties for E08-007 are reported. The resulting relative uncertainty found in the target polarization is determined to be less than or equal to 3.9%.

  6. Implementation of an Enhanced Measurement Control Program for handling nuclear safety samples at WSRC

    SciTech Connect

    Boler-Melton, C.; Holland, M.K.

    1991-01-01

    In the separation and purification of nuclear material, nuclear criticality safety (NCS) is of primary concern. The primary nuclear criticality safety controls utilized by the Savannah River Site (SRS) Separations Facilities involve administrative and process equipment controls. Additional assurance of NCS is obtained by identifying key process hold points where sampling is used to independently verify the effectiveness of production control. Nuclear safety measurements of samples from these key process locations provide a high degree of assurance that processing conditions are within administrative and procedural nuclear safety controls. An enhanced procedure management system aimed at making improvements in the quality, safety, and conduct of operation was implemented for Nuclear Safety Sample (NSS) receipt, analysis, and reporting. All procedures with nuclear safety implications were reviewed for accuracy and adequate detail to perform the analytical measurements safely, efficiently, and with the utmost quality. Laboratory personnel worked in a Deliberate Operating'' mode (a systematic process requiring continuous expert oversight during all phases of training, testing, and implementation) to initiate the upgrades. Thus, the effort to revise and review nuclear safety sample procedures involved a team comprised of a supervisor, chemist, and two technicians for each procedure. Each NSS procedure was upgraded to a Use Every Time'' (UET) procedure with sign-off steps to ensure compliance with each step for every nuclear safety sample analyzed. The upgrade program met and exceeded both the long and short term customer needs by improving measurement reliability, providing objective evidence of rigid adherence to program principles and requirements, and enhancing the system for independent verification of representative sampling from designated NCS points.

  7. Implementation of an Enhanced Measurement Control Program for handling nuclear safety samples at WSRC

    SciTech Connect

    Boler-Melton, C.; Holland, M.K.

    1991-12-31

    In the separation and purification of nuclear material, nuclear criticality safety (NCS) is of primary concern. The primary nuclear criticality safety controls utilized by the Savannah River Site (SRS) Separations Facilities involve administrative and process equipment controls. Additional assurance of NCS is obtained by identifying key process hold points where sampling is used to independently verify the effectiveness of production control. Nuclear safety measurements of samples from these key process locations provide a high degree of assurance that processing conditions are within administrative and procedural nuclear safety controls. An enhanced procedure management system aimed at making improvements in the quality, safety, and conduct of operation was implemented for Nuclear Safety Sample (NSS) receipt, analysis, and reporting. All procedures with nuclear safety implications were reviewed for accuracy and adequate detail to perform the analytical measurements safely, efficiently, and with the utmost quality. Laboratory personnel worked in a ``Deliberate Operating`` mode (a systematic process requiring continuous expert oversight during all phases of training, testing, and implementation) to initiate the upgrades. Thus, the effort to revise and review nuclear safety sample procedures involved a team comprised of a supervisor, chemist, and two technicians for each procedure. Each NSS procedure was upgraded to a ``Use Every Time`` (UET) procedure with sign-off steps to ensure compliance with each step for every nuclear safety sample analyzed. The upgrade program met and exceeded both the long and short term customer needs by improving measurement reliability, providing objective evidence of rigid adherence to program principles and requirements, and enhancing the system for independent verification of representative sampling from designated NCS points.

  8. Measurement of Nuclear Transparency for the A(e,e' pi^+) Reaction

    SciTech Connect

    B. Clasie; X. Qian; J. Arrington; R. Asaturyan; F. Benmokhtar; W. Boeglin; P. Bosted; A. Bruell; M. E. Christy; E. Chudakov; W. Cosyn; M. M. Dalton; A. Daniel; D. Day; D. Dutta; L. El Fassi; R. Ent; H. C. Fenker; J. Ferrer; N. Fomin; H. Gao; K. Garrow; D. Gaskell; C. Gray; T. Horn; G. M. Huber; M. K. Jones; N. Kalantarians; C. E. Keppel; K. Kramer; A. Larson; Y. Li; Y. Liang; A. F. Lung; S. Malace; P. Markowitz; A. Matsumura; D. G. Meekins; T. Mertens; G. A. Miller; T. Miyoshi; H. Mkrtchyan; R. Monson; T. Navasardyan; G. Niculescu; I. Niculescu; Y. Okayasu; A. K. Opper; C. Perdrisat; V. Punjabi; A. W. Rauf; V. M. Rodriquez; D. Rohe; J. Ryckebusch; J. Seely; E. Segbefia; G. R. Smith; M. Strikman; M. Sumihama; V. Tadevosyan; L. Tang; V. Tvaskis; A. Villano; W. F. Vulcan; F. R. Wesselmann; S. A. Wood; L. Yuan; X. C. Zheng

    2007-12-01

    We have measured the nuclear transparency of the A(e,e' pi^+) process in ^{2}H,^{12}C, ^{27}Al, ^{63}Cu and ^{197}Au targets. These measurements were performed at the Jefferson Laboratory over a four momentum transfer squared range Q^2 = 1.1 - 4.7 (GeV/c)^2. The nuclear transparency was extracted as the super-ratio of $(\\sigma_A/\\sigma_H)$ from data to a model of pion-electroproduction from nuclei without pi-N final state interactions. The Q^2 and atomic number dependence of the nuclear transparency both show deviations from traditional nuclear physics expectations, and are consistent with calculations that include the quantum chromodynamical phenomenon of color transparency.

  9. Lead Slowing Down Spectrometry Analysis of Data from Measurements on Nuclear Fuel

    SciTech Connect

    Warren, Glen A.; Anderson, Kevin K.; Kulisek, Jonathan A.; Danon, Yaron; Weltz, Adam; Gavron, Victor A.; Harris, Jason; Stewart, Trevor N.

    2015-01-12

    Improved non-destructive assay of isotopic masses in used nuclear fuel would be valuable for nuclear safeguards operations associated with the transport, storage and reprocessing of used nuclear fuel. Our collaboration is examining the feasibility of using lead slowing down spectrometry techniques to assay the isotopic fissile masses in used nuclear fuel assemblies. We present the application of our analysis algorithms on measurements conducted with a lead spectrometer. The measurements involved a single fresh fuel pin and discrete 239Pu and 235U samples. We are able to describe the isotopic fissile masses with root mean square errors over seven different configurations to 6.35% for 239Pu and 2.7% for 235U over seven different configurations. Funding Source(s):

  10. Studies of shock convergence in ICF implosions using nuclear burn history measurements

    NASA Astrophysics Data System (ADS)

    Rygg, J. R.; Delettrez, J. A.

    2005-10-01

    Ignition of ICF capsules on the NIF will be critically dependent on the quality of hot-spot heating due to converging shock waves. On OMEGA, the convergence of strong spherical shocks heats the inner gas sufficiently to induce nuclear fusion. Measurements of the time history of this nuclear burn show that the burn induced by shock convergence occurs several hundred picoseconds before the deceleration-phase compression burn. The nuclear burn history measurements of two distinct nuclear reactions will be compared to a Guderley self-similar imploding shock analysis, as well as to 1-D hydrodynamic simulations. This work was supported in part by LLE, LLNL, the U.S. DoE, the Univ. of Rochester, and the N.Y.State Energy Research and Development Authority.

  11. Calorimeter measures high nuclear heating rates and their gradients across a reactor test hole

    NASA Technical Reports Server (NTRS)

    Burwell, D.; Coombe, J. R.; Mc Bride, J.

    1970-01-01

    Pedestal-type calorimeter measures gamma-ray heating rates from 0.5 to 7.0 watts per gram of aluminum. Nuclear heating rate is a function of cylinder temperature change, measured by four chromel-alumel thermocouples attached to the calorimeter, and known thermoconductivity of the tested material.

  12. Measurement of Charged Pions from Neutrino-produced Nuclear Resonance

    SciTech Connect

    Simon, Clifford N.

    2014-01-01

    A method for identifying stopped pions in a high-resolution scintillator bar detector is presented. I apply my technique to measure the axial mass MΔAfor production of the Δ(1232) resonance by neutrino, with the result MΔA = 1.16±0.20 GeV (68% CL) (limited by statistics). The result is produced from the measured spectrum of reconstructed momentum-transfer Q2. I proceed by varying the value of MΔA in a Rein-Sehgal-based Monte Carlo to produce the best agreement, using shape only (not normalization). The consistency of this result with recent reanalyses of previous bubble-chamber experiments is discussed.

  13. Iodine magnetic moments measured by on-line nuclear orientation

    NASA Astrophysics Data System (ADS)

    Stone, N. J.; Rikovska, J.; Green, V. R.; Shaw, T. L.; Krane, K. S.; Walker, P. M.; Grant, I. S.

    1987-03-01

    On-Line measurements of magnetic dipole moments of117 122I are interpreted using coupling of the odd particles to a deformed core. The results show interesting effects of g7/2, d5/2 orbital admixtures in the odd-A isotopes, which are close to spherical. The odd-odd isotopes118, 120I show clear examples of shape co-existence.

  14. Spreadsheet analysis of gamma spectra for nuclear material measurements

    SciTech Connect

    Mosby, W.R.; Pace, D.M.

    1990-01-01

    A widely available commercial spreadsheet package for personal computers is used to calculate gamma spectra peak areas using both region of interest and peak fitting methods. The gamma peak areas obtained are used for uranium enrichment assays and for isotopic analyses of mixtures of transuranics. The use of spreadsheet software with an internal processing language allows automation of routine analysis procedures increasing ease of use and reducing processing errors while providing great flexibility in addressing unusual measurement problems. 4 refs., 9 figs.

  15. Recent Nuclear Astrophysics Measurements using the TwinSol Separator

    NASA Astrophysics Data System (ADS)

    Bardayan, D. W.; Ahn, T.; Allen, J.; Becchetti, F. D.; Blackmon, J. C.; Brodeur, M.; Frentz, B.; Gupta, Y. K.; Hall, M. R.; Hall, O.; Henderson, S.; Hu, J.; Kelly, J. M.; Kolata, J. J.; Long, A.; Long, J.; Macon, K.; Nicoloff, C.; O'Malley, P. D.; Ostdiek, K.; Pain, S. D.; Riggins, J.; Schultz, B. E.; Smith, M.; Strauss, S.; Torres-Isea, R. O.

    2016-07-01

    Many astrophysical events, such as novae and X-ray bursts, are powered by reactions with radioactive nuclei. Studying the properties of these nuclei in the laboratory can therefore further our understanding of these astrophysical explosions. The TwinSol separator at the University of Notre Dame has recently been used to produce intense (∼106 pps) beams of 17F. In this article, some of the first measurements with these beams are discussed.

  16. Cross section measurements via residual nuclear decays: Analysis methods

    SciTech Connect

    Zhou Fengqun; Gao Lei; Li Kuohu; Song Yueli; Zhang Fang; Kong Xiangzhong; Luo Junhua

    2009-11-15

    We develop an approach to calculating the pure cross section of the ground state of artificial radioactive nuclides that subtracts the effect of an excited state on the ground state. We apply a formalism to obtaining pure cross sections by subtracting the effect of excited states in the reactions {sup 122}Te(n,2n){sup 121}Te{sup g} and {sup 128}Te(n,2n){sup 127}Te{sup g}, induced by neutrons of about 14 MeV. The cross sections are measured by an activation relative to the {sup 93}Nb(n,2n){sup 92}Nb{sup m} reaction and are compared with results that take into account the effect of the excited state. Measurements are carried out by {gamma} detection using a coaxial high-purity germanium (HPGe) detector. As samples, spectroscopically pure Te powder is used. The fast neutrons are produced by the {sup 3}H(d,n){sup 4}He reaction. The neutron energies in these measurements are determined using the method of cross-section ratios between the {sup 90}Zr(n,2n){sup 89}Zr{sup m+g} and {sup 93}Nb(n,2n){sup 92}Nb{sup m} reactions.

  17. Optical pump-probe measurements of local nuclear spin coherence in semiconductor quantum wells.

    PubMed

    Sanada, H; Kondo, Y; Matsuzaka, S; Morita, K; Hu, C Y; Ohno, Y; Ohno, H

    2006-02-17

    We demonstrate local manipulation and detection of nuclear spin coherence in semiconductor quantum wells by an optical pump-probe technique combined with pulse rf NMR. The Larmor precession of photoexcited electron spins is monitored by time-resolved Kerr rotation (TRKR) as a measure of nuclear magnetic field. Under the irradiation of resonant pulsed rf magnetic fields, Rabi oscillations of nuclear spins are traced by TRKR signals. The intrinsic coherence time evaluated by a spin-echo technique reveals the dependence on the orientation of the magnetic field with respect to the crystalline axis as expected by the nearest neighbor dipole-dipole interaction. PMID:16606048

  18. Measuring of fissile isotope partial antineutrino spectra in direct experiment at nuclear reactor

    SciTech Connect

    Sinev, V. V.

    2009-11-15

    The direct measuring method is considered to get nuclear reactor antineutrino spectrum. We suppose to isolate partial spectra of the fissile isotopes by using the method of antineutrino spectrum extraction from the inverse beta-decay reaction positron spectrum applied at Rovno experiment. This admits to increase the accuracy of partial antineutrino spectra forming the total nuclear reactor spectrum. It is important for the analysis of the reactor core fuel composition and could be applied for non-proliferation purposes.

  19. A pair spectrometer for measuring multipolarities of energetic nuclear transitions

    NASA Astrophysics Data System (ADS)

    Gulyás, J.; Ketel, T. J.; Krasznahorkay, A. J.; Csatlós, M.; Csige, L.; Gácsi, Z.; Hunyadi, M.; Krasznahorkay, A.; Vitéz, A.; Tornyi, T. G.

    2016-02-01

    An electron-positron pair spectrometer has been designed and constructed for the simultaneous measurement of energy- and angular correlations of e+e- pairs. Experimental results are obtained over a wide angular range for high-energy transitions in 16O, 12C and 8Be. The results showed that the angular correlations between 50 and 180° of the e+e- pairs in the energy range between 6 and 18 MeV can be determined with sufficient resolution and efficiency in good agreement with the GEANT simulations.

  20. g -factors of conduction electrons and holes in B i2S e3 three-dimensional topological insulator

    NASA Astrophysics Data System (ADS)

    Wolos, A.; Szyszko, S.; Drabinska, A.; Kaminska, M.; Strzelecka, S. G.; Hruban, A.; Materna, A.; Piersa, M.; Borysiuk, J.; Sobczak, K.; Konczykowski, M.

    2016-04-01

    Bulk-related conduction electron spin resonance and conduction hole spin resonance were investigated in B i2S e3 , a three-dimensional topological insulator. Electrons in the conduction band and holes in the valence band both have spin ½. The effective g -factors for conduction electrons are equal to 27.3 ± 0.15 for magnetic field parallel to the c axis and 19.48 ± 0.07 for magnetic field perpendicular to the c axis, whereas for conduction holes 29.90 ± 0.09 for magnetic field parallel and 18.96 ± 0.04 for magnetic field perpendicular to the c axis, respectively. Nonparabolicity effects were not observed in the investigated low carrier concentration range, below 8 ×1017c m-3 . Large g -factors, higher by an order of magnitude than the free electron value, are due to strong spin-orbit interactions in B i2S e3 . The striking similarity of the spin resonances due to conduction electrons and holes confirms the peculiar symmetry between the conduction and valence bands of B i2S e3 , both having similar effective masses and spin character.

  1. Correlation measurements in nuclear {beta}-decay using traps and polarized low energy beams

    SciTech Connect

    Naviliat-Cuncic, Oscar

    2013-05-06

    Precision measurements in nuclear {beta}-decay provide sensitive means to test discrete symmetries in the weak interaction and to determine some of the fundamental constants in semi-leptonic decays, like the coupling of the lightest quarks to charged weak bosons. The main motivation of such measurements is to find deviations from Standard Model predictions as possible indications of new physics. In this contribution I will focus on two topics related to precision measurements in nuclear {beta}-decay: i) the determination of the V{sub ud} element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix from nuclear mirror transitions and ii) the search for exotic scalar or tensor contributions from {beta}{nu} angular correlations. The purpose is to underline the role being played by experimental techniques based on the confinement of radioactive species with atom and ion traps as well as the plans to use low energy polarized beams.

  2. First measurement of the ionization yield of nuclear recoils in liquid argon

    SciTech Connect

    Joshi, T.; Sangiorgio, Samuele; Bernstein, A.; Foxe, Michael P.; Hagmann, Chris; Jovanovic, Igor; Kazkaz, K.; Mozin, Vladimir V.; Norman, E. B.; Pereverzev, S. V.; Rebassoo, Finn O.; Sorensen, Peter F.

    2014-05-01

    Liquid phase argon has long been used as a target medium for particle detection via scintillation light. Recently there has been considerable interest in direct detection of both hypothetical darkmatter particles and coherent elastic neutrino nucleus scattering. These as-yet unobserved neutral particle interactions are expected to result in a recoiling argon atom O(keV), generally referred to in the literature as a nuclear recoil. This prompts the question of the available electromagnetic signal in a liquid argon detector. In this Letter we report the first measurement of the ionization yield (Qy), detected electrons per unit energy, resulting from nuclear recoils in liquid argon, measured at 6.7 keV. This is also the lowest energy measurement of nuclear recoils in liquid argon.

  3. Estimation of measurement accuracy of track point coordinates in nuclear photoemulsion

    NASA Astrophysics Data System (ADS)

    Shamanov, V. V.

    1995-03-01

    A simple method for an estimation of the measurement accuracy of track point coordinates in nuclear photoemulsion is described. The method is based on analysis of residual deviations of measured track points from a straight line approximating the track. Reliability of the algorithm is illustrated by Monte Carlo simulation. Examples of using the method for an estimation of the accuracy of track point coordinates measured with the microscope KSM-1 (VEB Carl Zeiss Jena) are given.

  4. Plutonium measurements with a fast-neutron multiplicity counter for nuclear safeguards applications

    NASA Astrophysics Data System (ADS)

    Dolan, Jennifer L.; Flaska, Marek; Poitrasson-Riviere, Alexis; Enqvist, Andreas; Peerani, Paolo; Chichester, David L.; Pozzi, Sara A.

    2014-11-01

    Measurements were performed at the Joint Research Centre in Ispra, Italy to field test a fast-neutron multiplicity counter developed at the University of Michigan. The measurements allowed the assessment of the system's photon discrimination abilities, efficiency when measuring neutron multiplicity, ability to characterize 240Pueff mass, and performance relative to a currently deployed neutron coincidence counter. This work is motivated by the need to replace and improve upon 3He neutron detection systems for nuclear safeguards applications.

  5. Plutonium Measurements with a Fast-Neutron Multiplicity Counter for Nuclear Safeguards Applications

    SciTech Connect

    Jennifer L. Dolan; Marek Flaska; Alexis Poitrasson-Riviere; Andreas Enqvist; Paolo Peerani; David L. Chichester; Sara A. Pozzi

    2014-11-01

    Measurements were performed at the Joint Research Centre in Ispra, Italy to field test a fast-neutron multiplicity counter developed at the University of Michigan. The measurements allowed the illustration of the system’s photon discrimination abilities, efficiency when measuring neutron multiplicity, ability to characterize 240Pueff mass, and performance relative to a currently deployed neutron coincidence counter. This work is motivated by the need to replace and improve upon 3He neutron detection systems for nuclear safeguards applications.

  6. Measurement method for the nuclear anapole moment of laser-trapped alkali-metal atoms

    SciTech Connect

    Gomez, E.; Aubin, S.; Sprouse, G. D.; Orozco, L. A.; DeMille, D. P.

    2007-03-15

    Weak interactions within a nucleus generate a nuclear spin dependent, parity-violating electromagnetic moment, the anapole moment. We analyze a method to measure the nuclear anapole moment through the electric dipole transition it induces between hyperfine states of the ground level. The method requires tight confinement of the atoms to position them at the antinode of a standing wave Fabry-Perot cavity driving the anapole-induced microwave E1 transition. We explore the necessary limits in the number of atoms, excitation fields, trap type, interrogation method, and systematic tests necessary for such measurements in francium, the heaviest alkali.

  7. Measurement of the nuclear polarization of hydrogen and deuterium molecules using a Lamb-shift polarimeter

    SciTech Connect

    Engels, Ralf Gorski, Robert; Grigoryev, Kiril; Mikirtychyants, Maxim; Rathmann, Frank; Seyfarth, Hellmut; Ströher, Hans; Weiss, Philipp; Kochenda, Leonid; Kravtsov, Peter; Trofimov, Viktor; Tschernov, Nikolay; Vasilyev, Alexander; Vznuzdaev, Marat; Schieck, Hans Paetz gen.

    2014-10-15

    Lamb-shift polarimeters are used to measure the nuclear polarization of protons and deuterons at energies of a few keV. In combination with an ionizer, the polarization of hydrogen and deuterium atoms was determined after taking into account the loss of polarization during the ionization process. The present work shows that the nuclear polarization of hydrogen or deuterium molecules can be measured as well, by ionizing the molecules and injecting the H{sub 2}{sup +} (or D{sub 2}{sup +}) ions into the Lamb-shift polarimeter.

  8. Recent Fast Neutron Imaging Measurements with the Fieldable Nuclear Materials Identification System

    SciTech Connect

    Mullens, James Allen; Mihalczo, John T; Archer, Daniel E; Thompson, Thad; Britton Jr, Charles L; Ezell, N Dianne Bull; Ericson, Milton Nance; Farquhar, Ethan; Lind, Randall F; Carter, Jake

    2015-01-01

    This paper describes some recent fast neutron imaging measurements of the fieldable nuclear materials identification system (FNMIS) under development by the National Nuclear Security Administration (NNSA-NA-22) for possible future use in arms control and nonproliferation applications. The general configuration of FNMIS has been previously described, and a description of the application-specific integrated circuit (ASIC) electronics designed for FNMIS has been reported. This paper presents initial imaging measurements performed at ORNL with a Thermo Fisher API 120 DT generator and the fast-neutron imaging module of FNMIS.

  9. Two Phase Flow Measurements by Nuclear Magnetic Resonance (NMR)

    SciTech Connect

    Altobelli, Stephen A; Fukushima, Eiichi

    2006-08-14

    In concentrated suspensions, there is a tendency for the solid phase to migrate from regions of high shear rate to regions of low shear (Leighton & Acrivos, 1987). In the early years that our effort was funded by the DOE Division of Basic Energy Science, quantitative measurement of this process in neutrally buoyant suspensions was a major focus (Abbott, et al., 1991; Altobelli, et al., 1991). Much of this work was used to improve multi-phase numerical models at Sandia National Laboratories. Later, our collaborators at Sandia and the University of New Mexico incorporated body forces into their numerical models of suspension flow (Rao, Mondy, Sun, et al., 2002). We developed experiments that allow us to study flows driven by buoyancy, to characterize these flows in well-known and useful engineering terms (Altobelli and Mondy, 2002) and to begin to explore the less well-understood area of flows with multiple solid phases (Beyea, Altobelli, et al., 2003). We also studied flows that combine the effects of shear and buoyancy, and flows of suspensions made from non-Newtonian liquids (Rao, Mondy, Baer, et al, 2002). We were able to demonstrate the usefulness of proton NMR imaging of liquid phase concentration and velocity and produced quantitative data not obtainable by other methods. Fluids flowing through porous solids are important in geophysics and in chemical processing. NMR techniques have been widely used to study liquid flow in porous media. We pioneered the extension of these studies to gas flows (Koptyug, et al, 2000, 2000, 2001, 2002). This extension allows us to investigate a wider range of Peclet numbers, and to gather data on problems of interest in catalysis. We devised two kinds of NMR experiments for three-phase systems. Both experiments employ two NMR visible phases and one phase that gives no NMR signal. The earlier method depends on the two visible phases differing in a NMR relaxation property. The second method (Beyea, Altobelli, et al., 2003) uses two

  10. Anisotropic electron g factor as a probe of the electronic structure of GaBixAs1 -x/GaAs epilayers

    NASA Astrophysics Data System (ADS)

    Broderick, Christopher A.; Mazzucato, Simone; Carrère, Hélène; Amand, Thierry; Makhloufi, Hejer; Arnoult, Alexandre; Fontaine, Chantal; Donmez, Omer; Erol, Ayşe; Usman, Muhammad; O'Reilly, Eoin P.; Marie, Xavier

    2014-11-01

    The electron Landé g factor (g*) is investigated both experimentally and theoretically in a series of GaBixAs1 -x /GaAs strained epitaxial layers, for bismuth compositions up to x =3.8 % . We measure g* via time-resolved photoluminescence spectroscopy, which we use to analyze the spin quantum beats in the polarization of the photoluminescence in the presence of an externally applied magnetic field. The experimental measurements are compared directly to atomistic tight-binding calculations on large supercells, which allows us to explicitly account for alloy disorder effects. We demonstrate that the magnitude of g* increases strongly with increasing Bi composition x and, based on the agreement between the theoretical calculations and experimental measurements, elucidate the underlying causes of the observed variation of g*. By performing measurements in which the orientation of the applied magnetic field is changed, we further demonstrate that g* is strongly anisotropic. We quantify the observed variation of g* with x , and its anisotropy, in terms of a combination of epitaxial strain and Bi-induced hybridization of valence states due to alloy disorder, which strongly perturbs the electronic structure.

  11. Density measurements of road overlays samples with nuclear gauges and a Step Frequency Radar

    NASA Astrophysics Data System (ADS)

    Fauchard, C.; Li, B.; Kadi, M.

    2012-04-01

    The density of Hot-Mix Asphalt layers (HMA) and thin overlays is an important parameter for the pavement quality and its long time performance. In the laboratory, the density could be measured with nuclear gauges based on the gamma rays absorption through cores samples drilled from the pavement. However, it is a destructive testing. For in-place control, the density could be measured with nuclear gauges based on the back-scattered gamma rays. But it is limited to overlays thickness greater than 3 cm. For both cases, nuclear gauges require specific training and certification for users. The use of a nuclear source (generally Cesium 137) is a major constraint for transportation and is a threat for operator safety. This work proposes a laboratory density measurement with an electromagnetic method, the Step Frequency Radar developped in our institute (Fauchard et al, 2009). It is based on the same physical principle than the Ground Penetrating Radar, but the used frequencies allow the study of very thin asphalt overlays less than 3 cm and the possible non-destructive measurement of in-place density with high performance. For this study, the dimensions of the device are designed to measure the density of slab samples (40*60*8 cm) in laboratory. The results are compared to the nuclear density measurement used in French Labs. Three kinds of slabs are implemented with four various degrees of compaction (88, 90, 92 and 94%) according to the French norm. Their composition is known and differs mainly with the nature of the aggregates (basalt, quartzite and limestone) that represent the main part of the mix materials. Then the permittivity of the samples is measured according to the reflected waves on surface and bottom slabs. A Complex Refractive Index Model gives the measured permittivity of the tested mix as a function of the compaction and the content, permittiviy and density of each component (filler, aggregates and bitumen). The obtained density is very closed to the

  12. Development, calibration, and experimental results obtained with an innovative calorimeter (CALMOS) for nuclear heating measurements

    SciTech Connect

    Carcreff, Hubert; Cloute-Cazalaa, Veronique; Salmon, Laurent

    2012-08-15

    Nuclear heating inside an MTR reactor has to be known in order to be able to control samples temperature during irradiation experiments. An R and D program has been carried out at CEA to design a new type of in-core calorimetric system. This new development, started in 2002, has for main objective to manufacture a calorimeter suitable to monitoring nuclear heating inside the 70 MWth OSIRIS material testing reactor operated by CEA's Nuclear Energy Division at the Saclay research center. An innovative calorimetric probe, associated to a specific handling system, has been designed to provide access to measurements both along the fissile height and on the upper part of the core, where nuclear heating still remains high. Two mock-ups of the probe were manufactured and tested in 2005 and 2009 in ex-core area of OSIRIS reactor for process validation, while a displacement system has been especially studied to move the probe along a given axial measurement range. This paper deals with the development, tests on preliminary mock-ups and the finalization of the probe. Main modeling and experimental results are presented. Moreover, alternative methods to calibration for nuclear heating rate measurements which are now possible with this new calorimeter are presented and discussed. (authors)

  13. Monte Carlo Simulation Study of a Differential Calorimeter Measuring the Nuclear Heating in Material Testing Reactors

    NASA Astrophysics Data System (ADS)

    Amharrak, H.; Reynard-Carette, C.; Lyoussi, A.; Carette, M.; Brun, J.; De Vita, C.; Fourmentel, D.; Villard, J.-F.; Guimbal, P.

    2016-02-01

    The nuclear heating measurements in Material Testing Reactors (MTRs) are crucial for the study of nuclear materials and fuels under irradiation. The reference measurements of this nuclear heating are especially performed by a differential calorimeter including a graphite sample material. Then these measurements are used for other materials, other geometries, or other experimental conditions in order to predict the nuclear heating and thermal conditions induced in the irradiation devices. This paper will present new simulations with MCNP Monte-Carlo transport code to determine the gamma heating profile inside the calorimeter. The whole complex geometry of the sensor has been considered. We use as an input source in the model, the photon spectra calculated in various positions of CARMEN-1 irradiation program in OSIRIS reactor. After a description of the differential calorimeter device, the MCNP modeling used for the calculations of radial profile of nuclear heating inside the calorimeter elements will be introduced. The obtained results of different simulations will be detailed and discussed in this paper. The charged particle equilibrium inside the calorimeter elements will be studied. Then we will focus on parametric studies of the various components of the calorimeter. The influence of source type will be also took into account. Moreover the influence of the material used for the sample will be described.

  14. Development, calibration and experimental results obtained with an innovative calorimeter (CALMOS) for nuclear heating measurements

    SciTech Connect

    Carcreff, H.; Cloute-Cazalaa, V.; Salmon, L.

    2011-07-01

    Nuclear heating inside an MTR reactor has to be known in order to be able to control samples temperature during irradiation experiments. An R and D program has been carried out at CEA to design a new type of in-core calorimetric system. This new development, started in 2002, has for main objective to manufacture a calorimeter suitable to monitoring nuclear heating inside the 70 MWth OSIRIS material testing reactor operated by CEA's Nuclear Energy Div. at the Saclay research center. An innovative calorimetric probe, associated to a specific handling system, has been designed to provide access to measurements both along the fissile height and on the upper part of the core, where nuclear heating still remains high. Two mock-ups of the probe were manufactured and tested in 2005 and 2009 in ex-core area of OSIRIS reactor for process validation, while a displacement system has been especially studied to move the probe along a given axial measurement range. This paper deals with the development, tests on preliminary mock-ups and the finalization of the probe. Main modeling and experimental results are presented. Moreover, alternative methods to calibration for nuclear heating rate measurements which are now possible with this new calorimeter are presented and discussed. (authors)

  15. Electron g-factor in bulk Ga1-xInxAsySb1-y/GaSb quaternary alloy and in GaSb/Ga1-xInxAsySb1-y/GaSb Spherical quantum dots

    NASA Astrophysics Data System (ADS)

    Sánchez-Cano, R.; Porras-Montenegro, N.

    2011-12-01

    Secure quantum communications require an entanglement-preserving photo-detector in which quantum information is transmitted by photon polarization through an mid infrared optical fiber system and then transferred to electron spin in a optoelectronic semiconductor device. Using interpolation scheme we have investigated the electron g-factor in bulk Ga1-xInxAsySb1-y quaternary alloy matched to GaSb as a function of Indium and Arsenic concentration on the complete range 0≤x,y≤1. A specific g-factor as a function of the radius in a spherical GaSb/Ga1-xInxAsySb1-y/GaSb quantum dot heterostructure is calculated. Furthermore, we present calculations of the energy states including the Zeeman effect on the electrons confined in quaternary heterostructure quantum dots, with a parabolic confining potential under applied magnetic fields. Our calculations have been worked out by using interpolating methods to find the band gap as a function of the Indium concentration in order to determine the conduction band-offset at room temperature in GaSb/Ga1-xInxAsySb1-y/GaSb heterostructure, within the effective-mass approximation. Experimental or theoretical electron g-factor, spin-orbit splitting Δso, and coupling matrix elements Ep = (2/m0)||2 value between the states of the lowest conduction band Γ6 and the upper valence bands Γ8 for Ga1-xInxAsySb1-y/GaSb quaternary alloy are not readily available. Our predictions show that electron g-factor values are in the range between the electron g-factor measured in bulk GaSb when x→0 (g = -9.25) and that measured in InAs when x→1 (g = -18.08), but there is a remarkable minimum in the g-factor value (g≃-23.14) at x≃0.67.

  16. Reactivity worth measurements at the IPEN/MB-01 nuclear reactor

    SciTech Connect

    Pinto, Leticia Negrao; Santos, Adimir dos

    2013-05-06

    Researches that aim to improve the performance of neutron transport codes and quality of nuclear cross section databases are very important to increase the accuracy of simulations and the quality of the analysis and prediction of phenomena in the nuclear field. In this context, relevant experimental data such as reactivity worth measurements are needed. The objective of this work was to perform a series of experiments of reactivity worth measurements, using a digital reactivity meter developed at IPEN. The experiments employed small metallic and ceramic samples inserted in the central region of the core of the experimental IPEN/MB-01 reactor. The theoretical analysis was performed by the MCNP-5 reactor physics code, developed and maintained by Los Alamos National Laboratory, and the ENDF/B-VII.0 nuclear data library.

  17. Can one measure nuclear matrix elements of neutrinoless double {beta} decay?

    SciTech Connect

    Rodin, Vadim; Faessler, Amand

    2009-10-15

    By making use of the isospin conservation by strong interaction, the Fermi 0{nu}{beta}{beta} nuclear matrix element M{sub F}{sup 0{nu}} is transformed to acquire the form of an energy-weighted double Fermi transition matrix element. This useful representation allows reconstruction of the total M{sub F}{sup 0{nu}} provided a small isospin-breaking Fermi matrix element between the isobaric analog state in the intermediate nucleus and the ground state of the daughter nucleus could be measured, e.g., by charge-exchange reactions. Such a measurement could set a scale for the 0{nu}{beta}{beta} nuclear matrix elements and help to discriminate between the different nuclear structure models in which calculated M{sub F}{sup 0{nu}} may differ by as much as a factor of 5 (that translates to about 20% difference in the total M{sup 0{nu}})

  18. Neutron cross section measurements at ORELA for improved nuclear data and their application.

    PubMed

    Guber, K H; Leal, L C; Sayer, R O; Koehler, P E; Valentine, T E; Derrien, H; Harvey, J A

    2005-01-01

    To support the Nuclear Criticality Safety Program, the Oak Ridge Electron Linear Accelerator (ORELA) has been used to measure the total and capture neutron cross sections of several nuclides in the energy range from 100 eV to -600 keV. Concerns about the use of existing cross section data in nuclear criticality calculations have been a prime motivator for the new cross-section measurements. Our new capture cross sections of aluminium, silicon, chlorine, fluorine and potassium in the energy range from 100 eV to 600 keV are substantially different from the cross sections in evaluated nuclear data files of ENDF/B-VI and JENDL-3.2. PMID:16604703

  19. Precision measurement of the nuclear polarization in laser-cooled, optically pumped 37K

    NASA Astrophysics Data System (ADS)

    Fenker, B.; Behr, J. A.; Melconian, D.; Anderson, R. M. A.; Anholm, M.; Ashery, D.; Behling, R. S.; Cohen, I.; Craiciu, I.; Donohue, J. M.; Farfan, C.; Friesen, D.; Gorelov, A.; McNeil, J.; Mehlman, M.; Norton, H.; Olchanski, K.; Smale, S.; Thériault, O.; Vantyghem, A. N.; Warner, C. L.

    2016-07-01

    We report a measurement of the nuclear polarization of laser-cooled, optically pumped 37K atoms which will allow us to precisely measure angular correlation parameters in the {β }+-decay of the same atoms. These results will be used to test the V ‑ A framework of the weak interaction at high precision. At the Triumf neutral atom trap (Trinat), a magneto-optical trap confines and cools neutral 37K atoms and optical pumping spin-polarizes them. We monitor the nuclear polarization of the same atoms that are decaying in situ by photoionizing a small fraction of the partially polarized atoms and then use the standard optical Bloch equations to model their population distribution. We obtain an average nuclear polarization of \\bar{P}=0.9913+/- 0.0009, which is significantly more precise than previous measurements with this technique. Since our current measurement of the β-asymmetry has 0.2 % statistical uncertainty, the polarization measurement reported here will not limit its overall uncertainty. This result also demonstrates the capability to measure the polarization to \\lt 0.1 % , allowing for a measurement of angular correlation parameters to this level of precision, which would be competitive in searches for new physics.

  20. Nuclear magnetic resonance for measurement of body composition in infants and children

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Measurement of body composition in infants and children is currently challenging. Air Displacement Plethysmography (ADP) has not been validated between ages 6 mo and 6 y and the requirement for stillness of the Dual-energy X-ray Absorptiometry (DXA) technique limits its use. Quantitative Nuclear Ma...

  1. Quantitative nuclear magnetic resonance to measure body composition in infants and children

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantitative Nuclear Magnetic Resonance (QMR) is being used in human adults to obtain measures of total body fat (FM) with high precision. The current study assessed a device specially designed to accommodate infants and children between 3 and 50 kg (EchoMRI-AH™). Body composition of 113 infants and...

  2. Aerial Radiation Measurements from the Fukushima Dai-ichi Nuclear Power Plant Accident

    SciTech Connect

    Guss, P. P.

    2012-07-16

    This document is a slide show type presentation concerning DOE and Aerial Measuring System (AMS) activities and results with respect to assessing the consequences of the releases from the Fukushima Dai-ichi Nuclear Power Plant. These include ground monitoring and aerial monitoring.

  3. Measuring Radon in Air, Soil and Water: An Introduction to Nuclear Physics for Schools

    ERIC Educational Resources Information Center

    Johansson, K. E.; Nilsson, Ch.; Wachtmeister, S.

    2007-01-01

    With the radon measurement activities at Stockholm House of Science, nuclear and experimental physics is introduced in a way that attracts the attention and interest of the students. These projects give the students the opportunity to use mobile detectors, either in their school, in the House of Science or in their homes. During 2006, 34 radon…

  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. Insight on the inconsistencies of Barkhausen signal measurements for radiation damage on nuclear reactor steel

    SciTech Connect

    Barroso, Soraia Pirfo; Fitzpatrick, Michael E.; Gillemot, Ferenc; Horváth, Marta; Horváth, Ákos; Szekely, Richard

    2014-02-18

    This paper focuses on the use of magnetic measurements, using Barkhausen signals to determine the irradiation effects, attempting to predict fracture toughness changes on nuclear reactor structural materials and correlating these measurements to mechanical testing and microstructure. For this study, two types of nuclear reactor materials were investigated: one sensitive to irradiation effects, the JRQ IAEA's reference material (A533B- -type); and one resistant material, 15KH2MFA WWER's reactor pressure vessel steel. The samples were carefully identified within the original heat block, i.e. forged or rolled plate. These calibrated samples were irradiated at different neutron fluences up to 10{sup 23} n/m{sup 2}. We show how microstructural anisotropy can mask the irradiation effects in the magnetic measurements. A correlation between irradiation effects and the magnetic measurements is explained based on this study.

  6. Insight on the inconsistencies of Barkhausen signal measurements for radiation damage on nuclear reactor steel

    NASA Astrophysics Data System (ADS)

    Barroso, Soraia Pirfo; Fitzpatrick, Michael E.; Gillemot, Ferenc; Horváth, Marta; Horváth, Ákos; Szekely, Richard

    2014-02-01

    This paper focuses on the use of magnetic measurements, using Barkhausen signals to determine the irradiation effects, attempting to predict fracture toughness changes on nuclear reactor structural materials and correlating these measurements to mechanical testing and microstructure. For this study, two types of nuclear reactor materials were investigated: one sensitive to irradiation effects, the JRQ IAEA's reference material (A533B- -type); and one resistant material, 15KH2MFA WWER's reactor pressure vessel steel. The samples were carefully identified within the original heat block, i.e. forged or rolled plate. These calibrated samples were irradiated at different neutron fluences up to 1023 n/m2. We show how microstructural anisotropy can mask the irradiation effects in the magnetic measurements. A correlation between irradiation effects and the magnetic measurements is explained based on this study.

  7. Proposal for Drell-Yan Measurements of Nucleon and Nuclear Structure with the FNAL Main Injector

    SciTech Connect

    Isenhower, L.D.; Sadler, M.E.; Arrinton, J.; Geesamn, D.F.; Holt, R.J.; Jackson, H.E.; Reimer, P.E.; Potterveld, D.H.; Brown, C.N.; Garvey, G.T.; Leitch, M.J.; /Los Alamos /Rutgers U. /Texas A-M /Valparaiso U.

    2001-04-01

    We propose measuring the fractional momentum (x) dependence of the ratio of the anti-down to anti-up quark distributions in the proton, {bar d}(x)/{bar u}(x), using proton induced Drell-Yan reactions at 120 GeV. Recent measurements by FNAL E866 unexpectedly show considerable x dependence in this ratio for x > 0.2. A lower energy primary proton beam from the Main Injector makes it possible to extend the E866 measurements to larger x with much higher precision. The apparatus will also be used with nuclear targets to measure parton energy loss and modifications to anti-quark distributions in nuclear targets at large x (x > 0.2).

  8. A comment on the validity of fragmentation parameters measured in nuclear emulsions. [cosmic ray nuclei

    NASA Technical Reports Server (NTRS)

    Waddington, C. J.

    1978-01-01

    Evidence is reexamined which has been cited as suggesting serious errors in the use of fragmentation parameters appropriate to an airlike medium deduced from measurements made in nuclear emulsions to evaluate corrections for certain effects in balloon-borne observations of cosmic-ray nuclei. Fragmentation parameters for hydrogenlike interactions are calculated and shown to be in overall good agreement with those obtained previously for air. Experimentally measured fragmentation parameters in emulsion are compared with values computed semiempirically, and reasonable agreement is indicated.

  9. Nuclear Resonance Fluorescence Measurements on ^237Np for Security and Safeguards Applications

    NASA Astrophysics Data System (ADS)

    Angell, C. T.; Joshi, T.; Yee, Ryan; Norman, E. B.; Kulp, W. D.; Warren, G. A.; Korbly, S.; Klimenko, A.; Wilson, C.; Copping, R.; Shuh, D. K.

    2009-10-01

    The smuggling of nuclear material and the diversion of fissile material for covert weapon programs both present grave risks to world security. Methods are needed to detect nuclear material smuggled in cargo, and for proper material accountability in civilian fuel re-processing facilities. Nuclear resonance fluorescence (NRF) is a technique that can address both needs. It is a non-destructive active interrogation method that provides isotope-specific information. It works by using a γ-ray beam to resonantly excite levels in a nucleus and observing the γ-rays emitted whose energy and intensity are characteristic of that isotope. ^237Np presents significant safeguard challenges; it is fissile yet currently has fewer safeguard restrictions. NRF measurements on ^237Np will expand the nuclear database and will permit designing interrogation and assay systems. Measurements were made using the bremsstrahlung beam at the HVRL at MIT on a 7 g target of ^237Np with two incident electron energies of 2.8 and 3.1 MeV. Results will be presented with discussion of the relevant nuclear structure necessary to predict levels in other actinides.

  10. The traceability chain of 131I measurements for nuclear medicine in Cuba.

    PubMed

    Oropesa, P; Moreno, Y; Serra, R A; Hernández, A T

    2012-09-01

    The national traceability chain for (131)I activity measurements performed in nuclear medicine in Cuba is described. At the highest (primary) level, liquid scintillation counting employing the CIEMAT/NIST method is used; at the secondary level, a secondary standard radionuclide calibrator is utilized that allows for a quick and simple transference of the measurement unit to the tertiary level of end-users' instruments. The equivalence of Cuban standards and the assessment of measurement uncertainties at the end-user level are determined through the results of measurement comparisons. PMID:22534014

  11. A potential nuclear magnetic resonance imaging approach for noncontact temperature measurement

    NASA Technical Reports Server (NTRS)

    Manatt, Stanley L.

    1989-01-01

    It is proposed that in a nuclear magnetic resonance (NMR) imaging experiment that it should be possible to measure temperature through an extended volume. The basis for such a measurement would depend upon sensing a temperature dependent on NMR parameter in an inert, volatile molecule (or fluid) filling the volume of interest. Exploratory work suggest that one suitable candidate for such a purpose might be CH3Cl. Possible parameters, other inert gases and feasible measurement schemes that might provide such temperature measurement are discussed.

  12. The CERN n_TOF facility: a unique tool for nuclear data measurement

    NASA Astrophysics Data System (ADS)

    Mingrone, F.; Aberle, O.; Andrzejewski, J.; Audouin, L.; Bécares, V.; Bacak, M.; Balibrea-Correa, J.; Barbagallo, M.; Barros, S.; Bečvář, F.; Beinrucker, C.; Berthoumieux, E.; Billowes, J.; Bosnar, D.; Brugger, M.; Caamaño, M.; Calviño, F.; Calviani, M.; Cano-Ott, D.; Cardella, R.; Casanovas, A.; Castelluccio, D. M.; Cerutti, F.; Chen, Y.; Chiaveri, E.; Colonna, N.; Cortés-Giraldo, M. A.; Cortés, G.; Cosentino, L.; Damone, L.; Diakaki, M.; Domingo-Pardo, C.; Dressler, R.; Dupont, E.; Durán, I.; Fernández-Domínguez, B.; Ferrari, A.; Ferreira, P.; Finocchiaro, P.; Furman, V.; Ganesan, S.; Garcia-Rios, A. A.; Gawlik, A.; Gheorghe, I.; Glodariu, T.; Gonçalves, I. F.; Gonzàlez, E.; Goverdovski, A.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Göbel, K.; Harada, H.; Heftrich, T.; Heinitz, S.; Heyse, J.; Jenkins, G.; Jericha, E.; Käppeler, F.; Kadi, Y.; Katabuchi, T.; Kavrigin, P.; Ketlerov, V.; Khryachkov, V.; Kimura, A.; Kivel, N.; Kokkoris, M.; Krtička, M.; Leal-Cidoncha, E.; Lederer, C.; Leeb, H.; Lerendegui, J.; Lo Meo, S.; Lonsdale, S.; Losito, R.; Macina, D.; Marganiec, J.; Martínez, T.; Massimi, C.; Mastinu, P.; Mastromarco, M.; Matteucci, F.; Maugeri, E. A.; Mendoza, E.; Mengoni, A.; Milazzo, P. M.; Mirea, M.; Montesano, S.; Musumarra, A.; Nolte, R.; Oprea, A.; Patronis, N.; Pavlik, A.; Perkowski, J.; Praena, J.; Quesada, J. M.; Rajeev, K.; Rauscher, T.; Reifarth, R.; Riego-Perez, A.; Rout, P.; Rubbia, C.; Ryan, J. A.; Sabaté-Gilarte, M.; Saxena, A.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Sedyshev, P.; Smith, A. G.; Stamatopoulos, A.; Tagliente, G.; Tain, J. L.; Tarifeño-Saldivia, A.; Tassan-Got, L.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Warren, S.; Weigand, M.; Weiss, C.; Wolf, C.; Woods, P. J.; Wright, T.; Žugec, P.

    2016-06-01

    The study of the resonant structures in neutron-nucleus cross-sections, and therefore of the compound-nucleus reaction mechanism, requires spectroscopic measurements to determine with high accuracy the energy of the neutron interacting with the material under study. To this purpose, the neutron time-of-flight facility n_TOF has been operating since 2001 at CERN. Its characteristics, such as the high intensity instantaneous neutron flux, the wide energy range from thermal to few GeV, and the very good energy resolution, are perfectly suited to perform high-quality measurements of neutron-induced reaction cross sections. The precise and accurate knowledge of these cross sections plays a fundamental role in nuclear technologies, nuclear astrophysics and nuclear physics. Two different measuring stations are available at the n_TOF facility, called EAR1 and EAR2, with different characteristics of intensity of the neutron flux and energy resolution. These experimental areas, combined with advanced detection systems lead to a great flexibility in performing challenging measurement of high precision and accuracy, and allow the investigation isotopes with very low cross sections, or available only in small quantities, or with very high specific activity. The characteristics and performances of the two experimental areas of the n_TOF facility will be presented, together with the most important measurements performed to date and their physics case. In addition, the significant upcoming measurements will be introduced.

  13. Pulsed, Photonuclear-induced, Neutron Measurements of Nuclear Materials with Composite Shielding

    SciTech Connect

    James Jones; Kevin Haskell; Rich Waston; William Geist; Jonathan Thron; Corey Freeman; Martyn Swinhoe; Seth McConchie; Eric Sword; Lee Montierth; John Zabriskie

    2011-07-01

    Active measurements were performed using a 10-MeV electron accelerator with inspection objects containing various nuclear and nonnuclear materials available at the Idaho National Laboratory’s Zero Power Physics Reactor (ZPPR) facility. The inspection objects were assembled from ZPPR reactor plate materials to evaluate the measurement technologies for the characterization of plutonium, depleted uranium or highly enriched uranium shielded by both nuclear and non-nuclear materials. A series of pulsed photonuclear, time-correlated measurements were performed with unshielded calibration materials and then compared with the more complex composite shield configurations. The measurements used multiple 3He detectors that are designed to detect fission neutrons between pulses of an electron linear accelerator. The accelerator produced 10-MeV bremsstrahlung X-rays at a repetition rate of 125 Hz (8 ms between pulses) with a 4-us pulse width. All inspected objects were positioned on beam centerline and 100 cm from the X-ray source. The time-correlated data was collected in parallel using both a Los Alamos National Laboratory-designed list-mode acquisition system and a commercial multichannel scaler analyzer. A combination of different measurement configurations and data analysis methods enabled the identification of each object. This paper describes the experimental configuration, the ZPPR inspection objects used, and the various measurement and analysis results for each inspected object.

  14. Investigations of defect structures and g factors for octahedral (CrO6)7‑ and (VO6)8‑ clusters in rutile-type crystals

    NASA Astrophysics Data System (ADS)

    Zhu, Lianxuan; Wang, Minjie

    2016-05-01

    The electron paramagnetic resonance (EPR) g factor formulas for Cr5+ and V4+ ions in Al2O3, TiO2 and VO2 crystals are deduced from Jahn-Teller effect and contributions of the charge transfer (CT) levels. The tetragonal distortions. ΔR(R∥‑ R⊥) = ‑0.0184,‑0.0045 and ‑0.0124 nm, and Δ𝜃 = 0∘, ‑ 0.001∘ and 0∘, for Al2O3:Cr5+, TiO2:V4+ and VO2, respectively. The calculations of the g factors agree well with the experimental values. The contributions of the CT levels to g factors increase with the increasing valence state. It must be taken into account in the precise calculations of g factors for the high valence state d1 ions in crystals.

  15. The g-factor of quasi-two-dimensional electrons in InAs/InGaAs/InAlAs inserted-channels

    NASA Astrophysics Data System (ADS)

    Pakmehr, Mehdi; Khaetskii, A.; McCombe, B. D.; Bhandari, N.; Cahay, M.; Chiatti, Olivio; Fischer, S. F.; Heyn, C.; Hansen, W.

    2015-08-01

    We have measured the Landau-level spin-splitting of two-dimensional electrons in the composite InAs/InGaAs channels of two InAs/InGaAs/InAlAs heterostructures with different alloy compositions by magnetotransport and THz magneto-photoconductivity in magnetic fields up to 10 T. The structures differ importantly in the mobility of the channel, the electron density and the composition of the barriers. The magnitudes of the experimental g-factors for B along the quantization axis and their anisotropies are larger by at least a factor of 2 than the corresponding calculated single particle values. The angular dependence of many-body exchange contributions and the effects of broadening of Landau-level densities of states are necessary for understanding this behaviour. We find evidence for a marked decrease of the exchange contribution at low perpendicular magnetic fields in the higher mobility sample from coincidence measurements, but no indications of such behaviour in the lower mobility sample.

  16. The g-factor of quasi-two-dimensional electrons in InAs/InGaAs/InAlAs inserted-channels

    SciTech Connect

    Pakmehr, Mehdi; Khaetskii, A.; McCombe, B. D.; Bhandari, N.; Cahay, M.; Chiatti, Olivio; Fischer, S. F.; Heyn, C.; Hansen, W.

    2015-08-24

    We have measured the Landau-level spin-splitting of two-dimensional electrons in the composite InAs/InGaAs channels of two InAs/InGaAs/InAlAs heterostructures with different alloy compositions by magnetotransport and THz magneto-photoconductivity in magnetic fields up to 10 T. The structures differ importantly in the mobility of the channel, the electron density and the composition of the barriers. The magnitudes of the experimental g-factors for B along the quantization axis and their anisotropies are larger by at least a factor of 2 than the corresponding calculated single particle values. The angular dependence of many-body exchange contributions and the effects of broadening of Landau–level densities of states are necessary for understanding this behaviour. We find evidence for a marked decrease of the exchange contribution at low perpendicular magnetic fields in the higher mobility sample from coincidence measurements, but no indications of such behaviour in the lower mobility sample.

  17. Nuclear data for r-process models from ion trap measurements

    NASA Astrophysics Data System (ADS)

    Clark, Jason

    2016-06-01

    To truly understand how elements are created in the universe via the astrophysical r process, accurate nuclear data are required. Historically, the isotopes involved in the r process have been difficult to access for study, but the development of new facilities and measurement techniques have put many of the r-process isotopes within reach. This paper will discuss the new CARIBU facility at Argonne National Laboratory and two pieces of experimental equipment, the Beta-decay Paul Trap and the Canadian Penning Trap, that will dramatically increase the nuclear data available for models of the astrophysical r process.

  18. Residential housing and nuclear attack: The ineffectiveness of current civil defence measures

    SciTech Connect

    Diacon, D.

    1985-01-01

    Diane Diacon of the Building and Social Housing Foundation has conducted an independent investigation of the question, and in this book she sums up the results. She first examines the nature of nuclear attack, and then goes on to explore the usefulness of specially-designed nuclear shelters and the likely disruption of essential services in the case of war. She concludes that the protection afforded by residential housing is in fact extremely poor, and that the civil defence measures contemplated by government bureaucrats are likely to be utterly ineffective.

  19. Simultaneous measurements of the X-ray and nuclear shock-bang times in ICF plasmas

    NASA Astrophysics Data System (ADS)

    Sutcliffe, G.; Sio, H.; Rinderknecht, H.; Frenje, J.; Zylstra, A.; Gatu Johnson, M.; Seguin, F.; Li, C. K.; Petrasso, R.; Rygg, J. R.; Macphee, A.; MacKinnon, A.; Le Pape, S.; Berzak Hopkins, L.; Regan, S. P.; Sangster, C.; Kilkenny, J.; Olson, R.

    2015-11-01

    Recent measurements of nuclear and x-ray shock-bang times in ICF implosions at OMEGA and the NIF provide new constraints on implosion modeling and may elucidate the underlying physics of e-i equilibration during the shock phase. As the ions are predominantly heated by the converging and rebounding shock, the ion temperature is initially much higher than the electron temperature and the difference relaxes at the e-i equilibration time scale. Nuclear and x-ray bang times are expected to differ because of different temperature dependence. At OMEGA, nuclear shock-bang time and burn history are routinely measured using streak camera diagnostics, while x-ray self-emission is observed with x-ray framing cameras. We are exploring the possibility of measuring both x-ray and nuclear shock-bang times with a single diagnostic with high relative accuracy, and will discuss the precision with which they can be made and the diagnostics necessary at OMEGA. This work was supported in part by NLUF, US DOE, and LLE.

  20. Deflection Measurements of a Thermally Simulated Nuclear Core Using a High-Resolution CCD-Camera

    NASA Technical Reports Server (NTRS)

    Stanojev, B. J.; Houts, M.

    2004-01-01

    Space fission systems under consideration for near-term missions all use compact. fast-spectrum reactor cores. Reactor dimensional change with increasing temperature, which affects neutron leakage. is the dominant source of reactivity feedback in these systems. Accurately measuring core dimensional changes during realistic non-nuclear testing is therefore necessary in predicting the system nuclear equivalent behavior. This paper discusses one key technique being evaluated for measuring such changes. The proposed technique is to use a Charged Couple Device (CCD) sensor to obtain deformation readings of electrically heated prototypic reactor core geometry. This paper introduces a technique by which a single high spatial resolution CCD camera is used to measure core deformation in Real-Time (RT). Initial system checkout results are presented along with a discussion on how additional cameras could be used to achieve a three- dimensional deformation profile of the core during test.

  1. Error reduction in gamma-spectrometric measurements of nuclear materials enrichment

    NASA Astrophysics Data System (ADS)

    Zaplatkina, D.; Semenov, A.; Tarasova, E.; Zakusilov, V.; Kuznetsov, M.

    2016-06-01

    The paper provides the analysis of the uncertainty in determining the uranium samples enrichment using non-destructive methods to ensure the functioning of the nuclear materials accounting and control system. The measurements were performed by a scintillation detector based on a sodium iodide crystal and the semiconductor germanium detector. Samples containing uranium oxide of different masses were used for the measurements. Statistical analysis of the results showed that the maximum enrichment error in a scintillation detector measurement can reach 82%. The bias correction, calculated from the data obtained by the semiconductor detector, reduces the error in the determination of uranium enrichment by 47.2% in average. Thus, the use of bias correction, calculated by the statistical methods, allows the use of scintillation detectors to account and control nuclear materials.

  2. Dry, portable calorimeter for nondestructive measurement of the activity of nuclear fuel

    DOEpatents

    Beyer, Norman S.; Lewis, Robert N.; Perry, Ronald B.

    1976-01-01

    The activity of a quantity of heat-producing nuclear fuel is measured rapidly, accurately and nondestructively by a portable dry calorimeter comprising a preheater, an array of temperature-controlled structures comprising a thermally guarded temperature-controlled oven, and a calculation and control unit. The difference between the amounts of electric power required to maintain the oven temperature with and without nuclear fuel in the oven is measured to determine the power produced by radioactive disintegration and hence the activity of the fuel. A portion of the electronic control system is designed to terminate a continuing sequence of measurements when the standard deviation of the variations of the amount of electric power required to maintain oven temperature is within a predetermined value.

  3. Three-dimensional direct measurement of cardiomyocyte volume, nuclearity, and ploidy in thick histological sections.

    PubMed

    Bensley, Jonathan Guy; De Matteo, Robert; Harding, Richard; Black, Mary Jane

    2016-01-01

    Quantitative assessment of myocardial development and disease requires accurate measurement of cardiomyocyte volume, nuclearity (nuclei per cell), and ploidy (genome copies per cell). Current methods require enzymatically isolating cells, which excludes the use of archived tissue, or serial sectioning. We describe a method of analysis that permits the direct simultaneous measurement of cardiomyocyte volume, nuclearity, and ploidy in thick histological sections. To demonstrate the utility of our technique, heart tissue was obtained from four species (rat, mouse, rabbit, sheep) at up to three life stages: prenatal, weaning and adulthood. Thick (40 μm) paraffin sections were stained with Wheat Germ Agglutinin-Alexa Fluor 488 to visualise cell membranes, and DAPI (4',6-diamidino-2-phenylindole) to visualise nuclei and measure ploidy. Previous methods have been restricted to thin sections (2-10 μm) and offer an incomplete picture of cardiomyocytes. Using confocal microscopy and three-dimensional image analysis software (Imaris Version 8.2, Bitplane AG, Switzerland), cardiomyocyte volume, nuclearity, and ploidy were measured. This method of staining and analysis of cardiomyocytes enables accurate morphometric measurements in thick histological sections, thus unlocking the potential of archived tissue. Our novel time-efficient method permits the entire cardiomyocyte to be visualised directly in 3D, eliminating the need for precise alignment of serial sections. PMID:27048757

  4. Three-dimensional direct measurement of cardiomyocyte volume, nuclearity, and ploidy in thick histological sections

    NASA Astrophysics Data System (ADS)

    Bensley, Jonathan Guy; de Matteo, Robert; Harding, Richard; Black, Mary Jane

    2016-04-01

    Quantitative assessment of myocardial development and disease requires accurate measurement of cardiomyocyte volume, nuclearity (nuclei per cell), and ploidy (genome copies per cell). Current methods require enzymatically isolating cells, which excludes the use of archived tissue, or serial sectioning. We describe a method of analysis that permits the direct simultaneous measurement of cardiomyocyte volume, nuclearity, and ploidy in thick histological sections. To demonstrate the utility of our technique, heart tissue was obtained from four species (rat, mouse, rabbit, sheep) at up to three life stages: prenatal, weaning and adulthood. Thick (40 μm) paraffin sections were stained with Wheat Germ Agglutinin-Alexa Fluor 488 to visualise cell membranes, and DAPI (4‧,6-diamidino-2-phenylindole) to visualise nuclei and measure ploidy. Previous methods have been restricted to thin sections (2–10 μm) and offer an incomplete picture of cardiomyocytes. Using confocal microscopy and three-dimensional image analysis software (Imaris Version 8.2, Bitplane AG, Switzerland), cardiomyocyte volume, nuclearity, and ploidy were measured. This method of staining and analysis of cardiomyocytes enables accurate morphometric measurements in thick histological sections, thus unlocking the potential of archived tissue. Our novel time-efficient method permits the entire cardiomyocyte to be visualised directly in 3D, eliminating the need for precise alignment of serial sections.

  5. Three-dimensional direct measurement of cardiomyocyte volume, nuclearity, and ploidy in thick histological sections

    PubMed Central

    Bensley, Jonathan Guy; De Matteo, Robert; Harding, Richard; Black, Mary Jane

    2016-01-01

    Quantitative assessment of myocardial development and disease requires accurate measurement of cardiomyocyte volume, nuclearity (nuclei per cell), and ploidy (genome copies per cell). Current methods require enzymatically isolating cells, which excludes the use of archived tissue, or serial sectioning. We describe a method of analysis that permits the direct simultaneous measurement of cardiomyocyte volume, nuclearity, and ploidy in thick histological sections. To demonstrate the utility of our technique, heart tissue was obtained from four species (rat, mouse, rabbit, sheep) at up to three life stages: prenatal, weaning and adulthood. Thick (40 μm) paraffin sections were stained with Wheat Germ Agglutinin-Alexa Fluor 488 to visualise cell membranes, and DAPI (4′,6-diamidino-2-phenylindole) to visualise nuclei and measure ploidy. Previous methods have been restricted to thin sections (2–10 μm) and offer an incomplete picture of cardiomyocytes. Using confocal microscopy and three-dimensional image analysis software (Imaris Version 8.2, Bitplane AG, Switzerland), cardiomyocyte volume, nuclearity, and ploidy were measured. This method of staining and analysis of cardiomyocytes enables accurate morphometric measurements in thick histological sections, thus unlocking the potential of archived tissue. Our novel time-efficient method permits the entire cardiomyocyte to be visualised directly in 3D, eliminating the need for precise alignment of serial sections. PMID:27048757

  6. Measurements of extinct fission products in nuclear bomb debris: Determination of the yield of the Trinity nuclear test 70 y later.

    PubMed

    Hanson, Susan K; Pollington, Anthony D; Waidmann, Christopher R; Kinman, William S; Wende, Allison M; Miller, Jeffrey L; Berger, Jennifer A; Oldham, Warren J; Selby, Hugh D

    2016-07-19

    This paper describes an approach to measuring extinct fission products that would allow for the characterization of a nuclear test at any time. The isotopic composition of molybdenum in five samples of glassy debris from the 1945 Trinity nuclear test has been measured. Nonnatural molybdenum isotopic compositions were observed, reflecting an input from the decay of the short-lived fission products (95)Zr and (97)Zr. By measuring both the perturbation of the (95)Mo/(96)Mo and (97)Mo/(96)Mo isotopic ratios and the total amount of molybdenum in the Trinity nuclear debris samples, it is possible to calculate the original concentrations of the (95)Zr and (97)Zr isotopes formed in the nuclear detonation. Together with a determination of the amount of plutonium in the debris, these measurements of extinct fission products allow for new estimates of the efficiency and yield of the historic Trinity test. PMID:27382169

  7. In situ radiation measurements at the former Soviet Nuclear Test Site

    SciTech Connect

    Tipton, W.J.

    1996-06-01

    A team from the Remote Sensing Laboratory conducted a series of in situ radiological measurements at the former Soviet Nuclear Test Site near Semipalatinsk, Kazakhstan, during the period of July 21-30, 1994. The survey team measured the terrestrial gamma radiation at selected areas on the site to determine the levels of natural and man-made radiation. The survey was part of a cooperative effort between the United States team and teams of radiation scientists from the National Nuclear Center of the Republic of Kazakhstan and the V.G. Khlopin Radium Institute in St. Petersburg, Russia. In addition to in situ radiation measurements made by the United States and Russian teams, soil samples were collected and analyzed by the Russian and Kazakhstani teams. All teams conducted their measurements at ten locations within the test site. The United States team also made a number of additional measurements to locate and verify the positions of three potential fallout plumes containing plutonium contamination from nonnuclear tests. In addition, the United States team made several measurements in Kurchatov City, the housing area used by personnel and their families who work(ed) at the test sites. Comparisons between the United States and Russian in situ measurements and the soil sample results are presented as well as comparisons with a Soviet aerial survey conducted in 1990-1991. The agreement between the different types of measurements made by all three countries was quite good.

  8. Development and calibration of the shielded measurement system for fissile contents measurements on irradiated nuclear fuel in dry storage.

    SciTech Connect

    Mosby, W. R.; Jensen, B. A.

    2002-05-31

    In recent years there has been a trend towards storage of Irradiated Nuclear Fuel (INF) in dry conditions rather than in underwater environments. At the same time, the Department of Energy (DOE) has begun encouraging custodians of INF to perform measurements on INF for which no recent fissile contents measurement data exists. INF, in the form of spent fuel from Experimental Breeder Reactor 2 (EBR-II), has been stored in close-fitting, dry underground storage locations at the Radioactive Scrap and Waste Facility (RSWF) at Argonne National Laboratory-West (ANL-W) for many years. In Fiscal Year 2000, funding was obtained from the DOE Office of Safeguards and Security Technology Development Program to develop and prepare for deployment a Shielded Measurement System (SMS) to perform fissile content measurements on INF stored in the RSWF. The SMS is equipped to lift an INF item out of its storage location, perform scanning neutron coincidence and high-resolution gamma-ray measurements, and restore the item to its storage location. The neutron and gamma-ray measurement results are compared to predictions based on isotope depletion and Monte Carlo neutral-particle transport models to provide confirmation of the accuracy of the models and hence of the fissile material contents of the item as calculated by the same models. This paper describes the SMS and discusses the results of the first calibration and validation measurements performed with the SMS.

  9. CALMOS: Innovative device for the measurement of nuclear heating in material testing reactors

    SciTech Connect

    Carcreff, H.

    2011-07-01

    An R and D program has been carried out since 2002 in order to improve gamma heating measurements in the 70 MWth OSIRIS Material Testing Reactor operated by CEA's Nuclear Energy Div. at the Saclay research center. Throughout this program an innovative calorimetric probe associated to a specific handling system has been designed in order to make measurements both along the fissile height and on the upper part of the core, where nuclear heating rates still remain high. Two mock-ups of the probe were manufactured and tested in 2005 and 2009 in ex-core area of OSIRIS reactor for the process validation, while a displacement system has been especially designed to move the probe axially. A final probe has been designed thanks to modeling results and to preliminary measurements obtained with mock-ups irradiated to a heating level of 2W/g, This paper gives an overview of the development, describes the calorimetric probe, and expected advantages such as the possibility to use complementary methods to get the nuclear heating measurement. Results obtained with mock-ups irradiated in ex-core area of the reactor are presented and discussed. (authors)

  10. Low level radioactivity measurement in support of the CTBTO. Comprehensive Nuclear-Test-Ban Treaty Organization

    PubMed

    Schulze; Auer; Werzi

    2000-07-01

    Radioactivity measurements, together with three other technologies: seismic, hydroacoustic and infrasound, are able to detect, identify and locate nuclear explosions down to 1 kt. Eighty stations worldwide, with a sensitivity of 10-30 microBq/m3 for 140Ba and 1 mBq/m m3 for 133Xe, have been or will be established in order to provide an estimated 90% detection probability within 10 days after a nuclear explosion. The equipment for manual stations--the high volume samplers, high sensitivity HPGe detectors and auxiliary measurement systems, as well as the automatic stations are described. The problems and results of atmospheric transport, site location as well as equipment and station operation are discussed. PMID:10879833

  11. Measurement of left ventricular ejection fraction in pediatric patients using the nuclear stethoscope

    SciTech Connect

    Spicer, R.L.; Rabinovitch, M.; Rosenthal, A.; Pitt, B.

    1984-01-01

    Left ventricular (LV) ejection fraction (EF) was measured in 25 patients, aged 2 weeks to 20 years (mean 8.6 years), using a portable nonimaging scintillation stethoscope. Technically satisfactory studies were obtained in 23 patients. LVEF was validated by cineangiography in 19 patients and by standard gated blood pool scintigraphy in 4. EF measured by the nuclear stethoscope correlated well with values obtained by cineangiography or scintigraphy over a wide range of EF values (18 to 79%). In children younger than 5 years (n . 11), the correlation was less satisfactory than in those older than 5 years. Although modifications in the instrument and further clinical trials with the stethoscope are needed before the device becomes clinically useful to pediatric cardiologists, our data indicate that the nuclear stethoscope can provide reliable assessment of LVEF in pediatric patients.

  12. Atomic mass measurements and nuclear spectroscopy at TRISTAN. Progress report, July 1, 1980-January 31, 1981

    SciTech Connect

    Brenner, D.S.

    1981-02-01

    This research program is concerned with measuring atomic masses and decay schemes of short-lived, neutron-rich fission products with the TRISTAN on-line mass separator located at the High Flux Beam Reactor (HFBR), Brookhaven National Laboratory. The determination of accurate masses for neutron-rich nuclei is useful in refining mass equations wich, in turn, are important for calculations related to astrophysical processes and to control and safety of nuclear reactors. During the period covered by this report, efforts have been to aid Brookhaven personnel in the installation and testing of TRISTAN and the associated computer systems, and to begin a program of measurements of ..beta..-ray end-point energies and nuclear decay schemes following successful demonstration of the facility. 2 figures.

  13. Intelligent monitor functional model with ionization chamber for mixed nuclear radiation field measurements

    SciTech Connect

    Valcov, N.; Purghel, L.; Celarel, A.

    1998-12-31

    By using the statistical discrimination technique, the components of an ionization current, due to a mixed radiation field, may be simultaneously measured. A functional model, including a series manufactured gamma-ray ratemeter was done, as an intermediate step in the design of specialized nuclear instrumentation, in order to check the concept of statistical discrimination method. The obtained results are in good agreement with the estimations of the statistical discrimination method.

  14. Nuclear data production, calculation and measurement: a global overview of the gamma heating issue

    NASA Astrophysics Data System (ADS)

    Colombier, A.-C.; Amharrak, H.; Fourmentel, D.; Ravaux, S.; Régnier, D.; Gueton, O.; Hudelot, J.-P.; Lemaire, M.

    2013-03-01

    The gamma heating evaluation in different materials found in current and future generations of nuclear reactor (EPRTM, GENIV, MTR-JHR), is becoming an important issue especially for the design of many devices (control rod, heavy reflector, in-core & out-core experiments…). This paper deals with the works started since 2009 in the Reactor Studies Department of CEA Cadarache in ordre to answer to several problematic which have been identified as well for nuclear data production and calculation as for experimental measurement methods. The selected subjects are: Development of a Monte Carlo code (FIFRELIN) to simulate the prompt fission gamma emission which represents the major part of the gamma heating production inside the core Production and qualification of new evaluations of nuclear data especially for radiative capture and inelastic neutron scattering which are the main sources of gamma heating out-core Development and qualification of a recommended method for the total gamma heating calculation using the Monte Carlo simulation code TRIPOLI-4 Development, test and qualification of new devices dedicated to the in-core gamma heating measurement as well in MTR-JHR as in zero power facilities (EOLE-MINERVE) of CEA, Cadarache to increase the experimental measurement accuracy.

  15. Compressibility, the measurement of surface tension, and particle size in molecular or nuclear matter.

    PubMed

    Dixmier, Marc

    2006-02-15

    It is shown that the interface shrinkage resulting from the capillary pressure difference between both sides of a curved interface is the product of a "standard shrinkage"kappagamma (kappa is the isothermal compressibility, gamma the interfacial tension) by a dimensionless factor that depends only on the shape of the sample of matter under study. The behaviour of the standard shrinkage in the critical domain shows that it cannot be a measure of the thickness of the liquid-vapour interface in that domain. The standard shrinkage of classical liquids somewhat above triple point is usually near to 0.048 v(c)(1/3) (v(c) is the critical molecular volume); exceptions to this rule are discussed. The variation of the standard shrinkage along the liquid-vapour coexistence curves of water and argon is presented; the effect of the interface shrinkage on the measured surface tension of liquids can become important within about 15% of the critical temperature. The standard shrinkage of solids is less than that of the corresponding liquids, and is of no consequence when measuring the surface tension of solids. The standard shrinkage of the nuclear fluid is 0.23 fm=0.09 v(c)(1/3). The saturation density of infinite nuclear matter is about 9% less than its value in atomic nuclei, and a term proportional to A(1/3) (A is the mass number) must be added to the nuclear binding energy formula. PMID:16266717

  16. Measured 19F(α,n) with VANDLE for Nuclear Safeguards

    NASA Astrophysics Data System (ADS)

    Peters, William; Clement, R. C. C.; Smith, M. S.; Pain, S.; Febbraro, M.; Pittman, S.; Thomspon, S.; Grinder, M.; Cizewski, J. A.; Reingold, C.; Manning, B.; Burcher, S.; Bardayan, D. W.; Tan, W.-P.; Stech, E.; Smith, M. K.; Avetisyan, R.; Gyurjinyan, A.; Lowe, M.; Ilyushkin, S.; Grzywacz, R.; Madurga, M.; Paulauskas, S. V.; Taylor, S. Z.; Smith, K.

    2015-10-01

    One of the most promising non-destructive assay (NDA) methods to monitor UF6 canisters consists of measuring gross neutron rates induced by uranium-decay alpha particles reacting with the fluorine and emitting a neutron. This method currently lacks reliable nuclear data on the 19F(α,n) reaction cross section to determine an accurate neutron yield rate for a given sample of UF6. We have measured the cross section and coincident neutron spectrum for the alpha-decay energy range using the VANDLE system. This experiment had two parts: first at Notre Dame with a LaF3 target and and a pulsed alpha-particle beam, and second at ORNL with a windowless He-gas target and a 19F beam. The motivation for this measurement and cross section results will be presented. This work is funded in part by the DOE Office of Science, the National Nuclear Security Administration SSAA and the Office of Defense Nuclear Nonproliferation R&D, and the NSF.

  17. Nuclear spin effects in optical lattice clocks

    SciTech Connect

    Boyd, Martin M.; Zelevinsky, Tanya; Ludlow, Andrew D.; Blatt, Sebastian; Zanon-Willette, Thomas; Foreman, Seth M.; Ye Jun

    2007-08-15

    We present a detailed experimental and theoretical study of the effect of nuclear spin on the performance of optical lattice clocks. With a state-mixing theory including spin-orbit and hyperfine interactions, we describe the origin of the {sup 1}S{sub 0}-{sup 3}P{sub 0} clock transition and the differential g factor between the two clock states for alkaline-earth-metal(-like) atoms, using {sup 87}Sr as an example. Clock frequency shifts due to magnetic and optical fields are discussed with an emphasis on those relating to nuclear structure. An experimental determination of the differential g factor in {sup 87}Sr is performed and is in good agreement with theory. The magnitude of the tensor light shift on the clock states is also explored experimentally. State specific measurements with controlled nuclear spin polarization are discussed as a method to reduce the nuclear spin-related systematic effects to below 10{sup -17} in lattice clocks.

  18. Study for Nuclear Structures of 22-35Na Isotopes via Measurements of Reaction Cross Sections

    NASA Astrophysics Data System (ADS)

    Suzuki, Shinji

    2014-09-01

    T. Ohtsubo, M. Nagashima, T. Ogura, Y. Shimbara (Grad. Sch. of Sc., Niigata Univ.), M.Takechi, H. Geissel, M. Winkler (GSI), D. Nishimura, T. Sumikama (Dept. of Phys., Tokyo Univ. of Sc.), M. Fukuda, M. Mihara, H. Uenishi (Dept. of Phys., Osaka Univ.), T. Kuboki, T. Suzuki, T. Yamaguchi, H. Furuki, C. S. Lee, K. Sato (Dept. of Phys., Saitama Univ.), A. Ozawa, H. Ohnishi, T. Moriguchi, S. Fukuda, Y. Ishibashi, D. Nagae, R. Nishikiori, T. Niwa (Inst. of Phys., Univ. of Tsukuba), N. Aoi (RCNP), Rui-Jiu Chen, N. Inabe, D. Kameda, T. Kubo, M. Lantz, T. Ohnishi, K. Okumura, H. Sakurai, H. Suzuki, H. Takeda, S. Takeuchi, K. Tanaka, Y. Yanagisawa (RIKEN), De-Qing Fang, Yu-Gang Ma (SINAP), T. Izumikawa (RI Ctr., Niigata Univ.), and S. Momota (Fac. of Engn., Kochi Univ. of Tech.) Reaction cross sections (σR) for 22-35Na isotopes have been measured at around 240 MeV/nucleon. The σR for 22-35Na were measured for the first time. Enhancement in cross sections is clearly observed from the systematics for stable nuclei, for isotopes with large mass numbers. These enhancement can be mainly ascribed to the nuclear deformation. We will discuss the nuclear structure (neutron skin, nuclear shell structure) for neutron-excess Na isotopes. T. Ohtsubo, M. Nagashima, T. Ogura, Y. Shimbara (Grad. Sch. of Sc., Niigata Univ.), M.Takechi, H. Geissel, M. Winkler (GSI), D. Nishimura, T. Sumikama (Dept. of Phys., Tokyo Univ. of Sc.), M. Fukuda, M. Mihara, H. Uenishi (Dept. of Phys., Osaka Univ.), T. Kuboki, T. Suzuki, T. Yamaguchi, H. Furuki, C. S. Lee, K. Sato (Dept. of Phys., Saitama Univ.), A. Ozawa, H. Ohnishi, T. Moriguchi, S. Fukuda, Y. Ishibashi, D. Nagae, R. Nishikiori, T. Niwa (Inst. of Phys., Univ. of Tsukuba), N. Aoi (RCNP), Rui-Jiu Chen, N. Inabe, D. Kameda, T. Kubo, M. Lantz, T. Ohnishi, K. Okumura, H. Sakurai, H. Suzuki, H. Takeda, S. Takeuchi, K. Tanaka, Y. Yanagisawa (RIKEN), De-Qing Fang, Yu-Gang Ma (SINAP), T. Izumikawa (RI Ctr., Niigata Univ.), and S. Momota (Fac. of Engn

  19. [The Chinese nuclear test and 'atoms for peace' as a measure for preventing nuclear armament of Japan: the nuclear non-proliferation policy of the United States and the introduction of light water reactors into Japan, 1964-1968].

    PubMed

    Yamazaki, Masakatsu

    2014-07-01

    Japan and the United States signed in 1968 a new atomic energy agreement through which US light-water nuclear reactors, including those of the Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Company, were to be introduced into Japan. This paper studies the history of negotiations for the 1968 agreement using documents declassified in the 1990s in the US and Japan. After the success of the Chinese nuclear test in October 1964, the United States became seriously concerned about nuclear armament of other countries in Asia including Japan. Expecting that Japan would not have its own nuclear weapons, the US offered to help the country to demonstrate its superiority in some fields of science including peaceful nuclear energy to counter the psychological effect of the Chinese nuclear armament. Driven by his own political agenda, the newly appointed Prime Minister Eisaku Sato responded to the US expectation favorably. When he met in January 1965 with President Johnson, Sato made it clear that Japan would not pursue nuclear weapons. Although the US continued its support after this visit, it nevertheless gave priority to the control of nuclear technology in Japan through the bilateral peaceful nuclear agreement. This paper argues that the 1968 agreement implicitly meant a strategic measure to prevent Japan from going nuclear and also a tactic to persuade Japan to join the Nuclear Non -Proliferation Treaty. PMID:25296517

  20. Results on the neutron energy distribution measurements at the RECH-1 Chilean nuclear reactor

    NASA Astrophysics Data System (ADS)

    Aguilera, P.; Molina, F.; Romero-Barrientos, J.

    2016-07-01

    Neutron activations experiments has been perform at the RECH-1 Chilean Nuclear Reactor to measure its neutron flux energy distribution. Samples of pure elements was activated to obtain the saturation activities for each reaction. Using - ray spectroscopy we identify and measure the activity of the reaction product nuclei, obtaining the saturation activities of 20 reactions. GEANT4 and MCNP was used to compute the self shielding factor to correct the cross section for each element. With the Expectation-Maximization algorithm (EM) we were able to unfold the neutron flux energy distribution at dry tube position, near the RECH-1 core. In this work, we present the unfolding results using the EM algorithm.

  1. Analysis of the nuclear measurement program for an optimized BR2 core configuration

    SciTech Connect

    Van Den Branden, G.; Kalcheva, S.; Sikik, E.; Koonen, E.

    2013-07-01

    This paper presents the analysis of the results of the Nuclear Measurement Program (NMP) executed during the shut-down of cycle 05/2012 of the BR2 reactor. The aim of the NMP was to determine the properties of a reactor core load with a new configuration of the control rods and to evaluate/verify the predicted numerical results by MCNPX. The methods used for the interpretation of the measurement results include combinations of an analytical method for determination of the axial relative control rod efficiency and least square techniques. (authors)

  2. Recent Results of Nuclear Mass Measurements at Storage Ring in IMP

    NASA Astrophysics Data System (ADS)

    Xu, H. S.; Zhang, Y. H.

    2014-09-01

    Recent commissioning of the Cooler Storage Ring at the Heavy Ion Research Facility in Lanzhou (HIRFL-CSR) has allowed us for direct mass measurements at the Institute of Modern Physics in Lanzhou (IMP), Chinese Academy of Sciences. A series of isochronous mass measurements have been carried out in the past few years using 78Kr, 86Kr, 58Ni, and 112Sn beams. The main results and the present status are presented in this talk, and the implications of these results with respect to nuclear structures and nucleosynthesis in the rp-process of x-ray bursts are discussed.

  3. Measurement of leaching from simulated nuclear-waste glass using radiotracers

    SciTech Connect

    Bates, J.K.; Jardine, L.J.; Steindler, M.J.

    1982-09-01

    The use of radiotracer spiking as a method of measuring the leaching from simulated nuclear-waste glass is shown to give results comparable with other analytical detection methods. The leaching behavior of /sup 85/Sr, /sup 106/Ru, /sup 133/Ba, /sup 137/Cs, /sup 141/Ce, /sup 152/Eu, and other isotopes is measured for several defense waste glasses. These tests show that radiotracer spiking is a sensitive, multielement technique that can provide leaching data, for actual waste elements, that are difficult to obtain by other methods. Additionally, a detailed procedure is described that allows spiked glass to be prepared with a suitable distribution of radionuclides.

  4. A two-axis goniometer for low-temperature nuclear magnetic resonance measurements on single crystals

    NASA Astrophysics Data System (ADS)

    Shiroka, T.; Casola, F.; Mesot, J.; Bachmann, W.; Ott, H.-R.

    2012-09-01

    We report on the construction of a two-axis goniometer intended for low-temperature, single-crystal nuclear magnetic resonance (NMR) measurements. With the use of home-made and commercially available parts, our simple probe-head design achieves good sensitivity, while maintaining a high angular precision and the ability to orient samples also when cooled to liquid helium temperatures. The probe with the goniometer is adapted to be inserted into a commercial 4He-flow cryostat, which fits into a wide-bore superconducting solenoid magnet. Selected examples of NMR measurements illustrate the operation of the device.

  5. A multiple sampling time projection ionization chamber for nuclear fragment tracking and charge measurement

    NASA Astrophysics Data System (ADS)

    Bauer, G.; Bieser, F.; Brady, F. P.; Chance, J. C.; Christie, W. F.; Gilkes, M.; Lindenstruth, V.; Lynen, U.; Müller, Walter F. J.; Romero, J. L.; Sann, H.; Tull, C. E.; Warren, P.

    1997-02-01

    A detector has been developed for the tracking and charge measurement of the projectile fragment nuclei produced in relativistic nuclear collisions. This device, MUSIC II, is a second generation Multiple Sampling Ionization Chamber (MUSIC), and employs the principles of ionization and time projection chambers. It provides unique charge determination for charges Z≥6, and excellent track position measurement. MUSIC II has been used most recently with the EOS (Equation of State) TPC and other EOS Collaboration detectors. Earlier it was used with other systems in experiments at the Heavy Ion Superconducting Spectrometer (HISS) facility at Lawrence Berkeley Laboratory and the ALADIN spectrometer at GSI.

  6. A confirmatory research approach to the measurement of EMI/RFI in commercial nuclear power plants

    SciTech Connect

    Kercel, S.W.

    1995-02-01

    The Oak Ridge National Laboratory (ORNL) is conducting confirmatory research on the measurement of electromagnetic/radio frequency interference (EMI/RFI) in nuclear power plants while it makes a good beginning, the currently available research data are not sufficient to characterize the EMI/RFI environment of the typical nuclear plant. Data collected over several weeks at each of several observation points are required to meet this need. To collect the required data, several approaches are examined, the most promising of which is the relatively new technology of application specific spectral receivers. While several spectral receiver designs have been described in the literature, none is well suited for nuclear power plant EMI/RFI surveys. This paper describes the development of two receivers specifically designed for nuclear power plant EMI/RFI surveys. One receiver surveys electric fields between 5 MHz and 8 GHz, while the other surveys magnetic fields between 305 Hz and 5 MHz. The results of field tests at TVA`s Bull Run Fossil Plant are reported.

  7. Prospects of Optical Single Atom Detection in Noble Gas Solids for Measurements of Rare Nuclear Reactions

    NASA Astrophysics Data System (ADS)

    Singh, Jaideep; Bailey, Kevin G.; Lu, Zheng-Tian; Mueller, Peter; O'Connor, Thomas P.; Xu, Chen-Yu; Tang, Xiaodong

    2013-04-01

    Optical detection of single atoms captured in solid noble gas matrices provides an alternative technique to study rare nuclear reactions relevant to nuclear astrophysics. I will describe the prospects of applying this approach for cross section measurements of the ^22Ne,,),25Mg reaction, which is the crucial neutron source for the weak s process inside of massive stars. Noble gas solids are a promising medium for the capture, detection, and manipulation of atoms and nuclear spins. They provide stable and chemically inert confinement for a wide variety of guest species. Because noble gas solids are transparent at optical wavelengths, the guest atoms can be probed using lasers. We have observed that ytterbium in solid neon exhibits intersystem crossing (ISC) which results in a strong green fluorescence (546 nm) under excitation with blue light (389 nm). Several groups have observed ISC in many other guest-host pairs, notably magnesium in krypton. Because of the large wavelength separation of the excitation light and fluorescence light, optical detection of individual embedded guest atoms is feasible. This work is supported by DOE, Office of Nuclear Physics, under contract DE-AC02-06CH11357.

  8. A confirmatory research approach to the measurement of EMI/RFI in commercial nuclear power plants

    SciTech Connect

    Kercel, S.W.

    1995-04-01

    The Oak Ridge National Laboratory (ORNL) is conducting confirmatory research on the measurement of electromagnetic/radio frequency interference (EMI/RFI) in nuclear power plants. While it makes a good beginning, the currently available research data are not sufficient to characterize the EMI/RFI environment of the typical nuclear plant. Data collected over several weeks at each of several observation points are required to meet this need. To collect the required data, several approaches are examined, the most promising of which is the relatively new technology of application specific spectral receivers. While several spectral receiver designs have been described in the literature, none is well suited for nuclear power plant EMI/RFI surveys. This paper describes the development of two receivers specifically designed for nuclear power plant EMI/RFI surveys. One receiver surveys electric fields between 5 MHz and 8 GHz, while the other surveys magnetic fields between 305 Hz and 5 MHz. The results of field tests at TVA`s Bull Run Fossil Plant are reported.

  9. Measurement of Scintillation and Ionization Yield and Scintillation Pulse Shape from Nuclear Recoils in Liquid Argon

    SciTech Connect

    Cao, H.

    2015-05-26

    We have measured the scintillation and ionization yield of recoiling nuclei in liquid argon as a function of applied electric field by exposing a dual-phase liquid argon time projection chamber (LAr-TPC) to a low energy pulsed narrow band neutron beam produced at the Notre Dame Institute for Structure and Nuclear Astrophysics. Liquid scintillation counters were arranged to detect and identify neutrons scattered in the TPC and to select the energy of the recoiling nuclei. We also report measurements of the scintillation yields for nuclear recoils with energies from 10.3 to 57.3 keV and for median applied electric fields from 0 to 970 V/cm. For the ionization yields, we report measurements from 16.9 to 57.3 keV and for electric fields from 96.4 to 486 V/cm. Furthermore, we report the observation of an anticorrelation between scintillation and ionization from nuclear recoils, which is similar to the anticorrelation between scintillation and ionization from electron recoils. Assuming that the energy loss partitions into excitons and ion pairs from 83mKr internal conversion electrons is comparable to that from 207Bi conversion electrons, we obtained the numbers of excitons (Nex) and ion pairs (Ni) and their ratio (Nex/Ni) produced by nuclear recoils from 16.9 to 57.3 keV. Motivated by arguments suggesting direction sensitivity in LAr-TPC signals due to columnar recombination, a comparison of the light and charge yield of recoils parallel and perpendicular to the applied electric field is presented for the first time.

  10. Measurement of Scintillation and Ionization Yield and Scintillation Pulse Shape from Nuclear Recoils in Liquid Argon

    DOE PAGESBeta

    Cao, H.

    2015-05-26

    We have measured the scintillation and ionization yield of recoiling nuclei in liquid argon as a function of applied electric field by exposing a dual-phase liquid argon time projection chamber (LAr-TPC) to a low energy pulsed narrow band neutron beam produced at the Notre Dame Institute for Structure and Nuclear Astrophysics. Liquid scintillation counters were arranged to detect and identify neutrons scattered in the TPC and to select the energy of the recoiling nuclei. We also report measurements of the scintillation yields for nuclear recoils with energies from 10.3 to 57.3 keV and for median applied electric fields from 0more » to 970 V/cm. For the ionization yields, we report measurements from 16.9 to 57.3 keV and for electric fields from 96.4 to 486 V/cm. Furthermore, we report the observation of an anticorrelation between scintillation and ionization from nuclear recoils, which is similar to the anticorrelation between scintillation and ionization from electron recoils. Assuming that the energy loss partitions into excitons and ion pairs from 83mKr internal conversion electrons is comparable to that from 207Bi conversion electrons, we obtained the numbers of excitons (Nex) and ion pairs (Ni) and their ratio (Nex/Ni) produced by nuclear recoils from 16.9 to 57.3 keV. Motivated by arguments suggesting direction sensitivity in LAr-TPC signals due to columnar recombination, a comparison of the light and charge yield of recoils parallel and perpendicular to the applied electric field is presented for the first time.« less

  11. DAPI-fluorescent fading: a problem in microscopy or a way to measure nuclear DNA content?

    NASA Astrophysics Data System (ADS)

    Gallardo-Escárate, Cristian; Álvarez-Borrego, Josué; Kober, V.; del Río-Portilla, Miguel Á.

    2006-01-01

    In observation by confocal or conventional fluorescence microscopy, the retardation of the lost in fluorescence, from highest signal of fluorescence to lowest intensity are important factors in order to obtain accurate images. This problem is very common in fluorochromes for nuclear DNA and especially for DAPI stain. The fluorescence of DAPI is rapidly lost when it is exposure to excitation by ultra violet (UV) light, and especially under optimal condition of observation. Although the fading process could be retardate by using of mounting medium with antifading solutions, the photochemical process underlying the fluorescence decay has not yet been fully explained. In addiction, neither relationship has been tested between the fluorescence fading and nuclear DNA content. However, the capacity of the DNA to absorb UV light is knows. In order to test this relationship we measured by means of image analysis the fluorescence intensity in several nuclei types during a fading period. The analysis was performed by an algorithm specifically built in MATLAB software. The relationship between nuclear DNA content and DAPI-fluorescence fading was found equal to 99%. This study demonstrates the feasibility for estimates genome size by quantification of fluorescence fading. In this context, the present method allows to measure nuclear DNA content in several medical applications (cancer, HIV, organ transplants, etc). Nowadays, for measuring DNA content, flow cytometry is widely used; however, with the flow cytometry method it is not possible to select a specific group of cells, such as from a specific region of a tumor. Moreover, the using of image analysis allows automatizing diagnostics procedures.

  12. Uncertainty quantification for nuclear density functional theory and information content of new measurements.

    PubMed

    McDonnell, J D; Schunck, N; Higdon, D; Sarich, J; Wild, S M; Nazarewicz, W

    2015-03-27

    Statistical tools of uncertainty quantification can be used to assess the information content of measured observables with respect to present-day theoretical models, to estimate model errors and thereby improve predictive capability, to extrapolate beyond the regions reached by experiment, and to provide meaningful input to applications and planned measurements. To showcase new opportunities offered by such tools, we make a rigorous analysis of theoretical statistical uncertainties in nuclear density functional theory using Bayesian inference methods. By considering the recent mass measurements from the Canadian Penning Trap at Argonne National Laboratory, we demonstrate how the Bayesian analysis and a direct least-squares optimization, combined with high-performance computing, can be used to assess the information content of the new data with respect to a model based on the Skyrme energy density functional approach. Employing the posterior probability distribution computed with a Gaussian process emulator, we apply the Bayesian framework to propagate theoretical statistical uncertainties in predictions of nuclear masses, two-neutron dripline, and fission barriers. Overall, we find that the new mass measurements do not impose a constraint that is strong enough to lead to significant changes in the model parameters. The example discussed in this study sets the stage for quantifying and maximizing the impact of new measurements with respect to current modeling and guiding future experimental efforts, thus enhancing the experiment-theory cycle in the scientific method. PMID:25860736

  13. Uncertainty quantification for nuclear density functional theory and information content of new measurements

    DOE PAGESBeta

    McDonnell, J. D.; Schunck, N.; Higdon, D.; Sarich, J.; Wild, S. M.; Nazarewicz, W.

    2015-03-24

    Statistical tools of uncertainty quantification can be used to assess the information content of measured observables with respect to present-day theoretical models, to estimate model errors and thereby improve predictive capability, to extrapolate beyond the regions reached by experiment, and to provide meaningful input to applications and planned measurements. To showcase new opportunities offered by such tools, we make a rigorous analysis of theoretical statistical uncertainties in nuclear density functional theory using Bayesian inference methods. By considering the recent mass measurements from the Canadian Penning Trap at Argonne National Laboratory, we demonstrate how the Bayesian analysis and a direct least-squaresmore » optimization, combined with high-performance computing, can be used to assess the information content of the new data with respect to a model based on the Skyrme energy density functional approach. Employing the posterior probability distribution computed with a Gaussian process emulator, we apply the Bayesian framework to propagate theoretical statistical uncertainties in predictions of nuclear masses, two-neutron dripline, and fission barriers. Overall, we find that the new mass measurements do not impose a constraint that is strong enough to lead to significant changes in the model parameters. In addition, the example discussed in this study sets the stage for quantifying and maximizing the impact of new measurements with respect to current modeling and guiding future experimental efforts, thus enhancing the experiment-theory cycle in the scientific method.« less

  14. Uncertainty quantification for nuclear density functional theory and information content of new measurements

    SciTech Connect

    McDonnell, J. D.; Schunck, N.; Higdon, D.; Sarich, J.; Wild, S. M.; Nazarewicz, W.

    2015-03-24

    Statistical tools of uncertainty quantification can be used to assess the information content of measured observables with respect to present-day theoretical models, to estimate model errors and thereby improve predictive capability, to extrapolate beyond the regions reached by experiment, and to provide meaningful input to applications and planned measurements. To showcase new opportunities offered by such tools, we make a rigorous analysis of theoretical statistical uncertainties in nuclear density functional theory using Bayesian inference methods. By considering the recent mass measurements from the Canadian Penning Trap at Argonne National Laboratory, we demonstrate how the Bayesian analysis and a direct least-squares optimization, combined with high-performance computing, can be used to assess the information content of the new data with respect to a model based on the Skyrme energy density functional approach. Employing the posterior probability distribution computed with a Gaussian process emulator, we apply the Bayesian framework to propagate theoretical statistical uncertainties in predictions of nuclear masses, two-neutron dripline, and fission barriers. Overall, we find that the new mass measurements do not impose a constraint that is strong enough to lead to significant changes in the model parameters. In addition, the example discussed in this study sets the stage for quantifying and maximizing the impact of new measurements with respect to current modeling and guiding future experimental efforts, thus enhancing the experiment-theory cycle in the scientific method.

  15. Uncertainty quantification for nuclear density functional theory and information content of new measurements

    SciTech Connect

    McDonnell, J. D.; Schunck, N.; Higdon, D.; Sarich, J.; Wild, S. M.; Nazarewicz, W.

    2015-03-24

    Statistical tools of uncertainty quantification can be used to assess the information content of measured observables with respect to present-day theoretical models, to estimate model errors and thereby improve predictive capability, to extrapolate beyond the regions reached by experiment, and to provide meaningful input to applications and planned measurements. To showcase new opportunities offered by such tools, we make a rigorous analysis of theoretical statistical uncertainties in nuclear density functional theory using Bayesian inference methods. By considering the recent mass measurements from the Canadian Penning Trap at Argonne National Laboratory, we demonstrate how the Bayesian analysis and a direct least-squares optimization, combined with high-performance computing, can be used to assess the information content of the new data with respect to a model based on the Skyrme energy density functional approach. Employing the posterior probability distribution computed with a Gaussian process emulator, we apply the Bayesian framework to propagate theoretical statistical uncertainties in predictions of nuclear masses, two-neutron dripline, and fission barriers. Overall, we find that the new mass measurements do not impose a constraint that is strong enough to lead to significant changes in the model parameters. As a result, the example discussed in this study sets the stage for quantifying and maximizing the impact of new measurements with respect to current modeling and guiding future experimental efforts, thus enhancing the experiment-theory cycle in the scientific method.

  16. Highly Depleted Ethane and Slightly Depleted Methanol in Comet 21P/Giacobini-Zinner: Application of Empirical g-Factors for CH3OH Near 50K

    NASA Technical Reports Server (NTRS)

    DiSanti, Michael A.; Bonev, Boncho P.; Mumma, Michael J.; Villanueva, Geronimo L.

    2010-01-01

    We report high resolution (lambda/delta lambda approximately 24,000) observations of Comet 21 P/Giacobini-Zinner (21P) between approximately 2.85 -- 3.54 micrometers, obtained with NIRSPEC at Keck 2 on UT 2005 June 03 (R(sub h) = 1.12 AU, delta = 1.45 AU). These simultaneously sampled multiple emissions from the v7 band of C2H6 and the v2 and v3 bands of CH3OH, together with several hot bands of H2O, permitting a direct measure of parent volatile abundances in 21P. Our spectra reveal highly depleted C2H6 (0.13-0.14 percent relative to H2O) and CH3OH/C2H6 approximately 10, consistent with previously published abundances from observations in the IR [1,2] and millimeter sub-mm (reporting CH3OH/H2O [3]) during its previous apparition in 1998. We observed similarly high CH3OH/C2H6, and also similar rotational temperature to that measured for 21 P, in Comet 8P/Tuttle [4,5]. We used our (higher signal-to-noise) NIRSPEC observations of 8P to produce effective (empirical) CH3OH g-factors for several lines in the v2 band. These will be presented together with interpretation of our results, including constraints on the spin temperature of water. We acknowledge support from the NASA Planetary Atmospheres, Planetary Astronomy, and Astrobiology Programs and from the NSF Astronomy and Astrophysics Research Grants Program.

  17. Attempts to develop a new nuclear measurement technique of β-glucuronidase levels in biological samples

    NASA Astrophysics Data System (ADS)

    Ünak, T.; Avcibasi, U.; Yildirim, Y.; Çetinkaya, B.

    2003-01-01

    β-Glucuronidase is one of the most important hydrolytic enzymes in living systems and plays an essential role in the detoxification pathway of toxic materials incorporated into the metabolism. Some organs, especially liver and some tumour tissues, have high level of β-glucuronidase activity. As a result the enzymatic activity of some kind of tumour cells, the radiolabelled glucuronide conjugates of cytotoxic, as well as radiotoxic compounds have potentially very valuable diagnostic and therapeutic applications in cancer research. For this reason, a sensitive measurement of β-glucuronidase levels in normal and tumour tissues is a very important step for these kinds of applications. According to the classical measurement method of β-glucuronidase activity, in general, the quantity of phenolphthalein liberated from its glucuronide conjugate, i.e. phenolphthalein-glucuronide, by β-glucuronidase has been measured by use of the spectrophotometric technique. The lower detection limit of phenolphthalein by the spectrophotometric technique is about 1 3 μg. This means that the β-glucuronidase levels could not be detected in biological samples having lower levels of β-glucuronidase activity and therefore the applications of the spectrophotometric technique in cancer research are very seriously limited. Starting from this consideration, we recently attempted to develop a new nuclear technique to measure much lower concentrations of β-glucuronidase in biological samples. To improve the detection limit, phenolphthalein-glucuronide and also phenyl-N-glucuronide were radioiodinated with 131I and their radioactivity was measured by use of the counting technique. Therefore, the quantity of phenolphthalein or aniline radioiodinated with 131I and liberated by the deglucuronidation reactivity of β-glucuronidase was used in an attempt to measure levels lower than the spectrophotometric measurement technique. The results obtained clearly verified that 0.01 pg level of

  18. Attempts to develop a new nuclear measurement technique of β-glucuronidase levels in biological samples

    NASA Astrophysics Data System (ADS)

    Ünak, T.; Avcibasi, U.; Yildirim, Y.; Çetinkaya, B.

    2003-01-01

    β-Glucuronidase is one of the most important hydrolytic enzymes in living systems and plays an essential role in the detoxification pathway of toxic materials incorporated into the metabolism. Some organs, especially liver and some tumour tissues, have high level of β-glucuronidase activity. As a result the enzymatic activity of some kind of tumour cells, the radiolabelled glucuronide conjugates of cytotoxic, as well as radiotoxic compounds have potentially very valuable diagnostic and therapeutic applications in cancer research. For this reason, a sensitive measurement of β-glucuronidase levels in normal and tumour tissues is a very important step for these kinds of applications. According to the classical measurement method of β-glucuronidase activity, in general, the quantity of phenolphthalein liberated from its glucuronide conjugate, i.e. phenolphthalein-glucuronide, by β-glucuronidase has been measured by use of the spectrophotometric technique. The lower detection limit of phenolphthalein by the spectrophotometric technique is about 1-3 μg. This means that the β-glucuronidase levels could not be detected in biological samples having lower levels of β-glucuronidase activity and therefore the applications of the spectrophotometric technique in cancer research are very seriously limited. Starting from this consideration, we recently attempted to develop a new nuclear technique to measure much lower concentrations of β-glucuronidase in biological samples. To improve the detection limit, phenolphthalein-glucuronide and also phenyl-N-glucuronide were radioiodinated with 131I and their radioactivity was measured by use of the counting technique. Therefore, the quantity of phenolphthalein or aniline radioiodinated with 131I and liberated by the deglucuronidation reactivity of β-glucuronidase was used in an attempt to measure levels lower than the spectrophotometric measurement technique. The results obtained clearly verified that 0.01 pg level of

  19. Tuning the g-factor of neutral and charged excitons confined to self-assembled (Al,Ga)As shell quantum dots

    SciTech Connect

    Corfdir, P. Van Hattem, B.; Phillips, R. T.; Fontana, Y.; Russo-Averchi, E.; Heiss, M.; Fontcuberta i Morral, A.

    2014-12-01

    We study the neutral exciton (X) and charged exciton (CX) transitions from (Al,Ga)As shell quantum dots located in core-shell nanowires, in the presence of a magnetic field. The g-factors and the diamagnetic coefficients of both the X and the CX depend on the orientation of the field with respect to the nanowire axis. The aspect ratio of the X wavefunction is quantified based on the anisotropy of the diamagnetic coefficient. For specific orientations of the magnetic field, it is possible to cancel the g-factor of the bright states of the X and the CX by means of an inversion of the sign of the hole's g-factor, which is promising for quantum information processing applications.

  20. Measurement of conductivity and permittivity on samples sealed in nuclear magnetic resonance tubes

    SciTech Connect

    Huang, W.; Angell, C. A.; Yarger, J. L.; Richert, R.

    2013-07-15

    We present a broadband impedance spectroscopy instrument designed to measure conductivity and/or permittivity for samples that are sealed in glass tubes, such as the standard 5 mm tubes used for nuclear magnetic resonance experiments. The calibrations and corrections required to extract the dielectric properties of the sample itself are outlined. It is demonstrated that good estimates of the value of dc-conductivity can be obtained even without correcting for the effects of glass or air on the overall impedance. The approach is validated by comparing data obtained from samples sealed in nuclear magnetic resonance tubes with those from standard dielectric cells, using glycerol and butylmethylimidazolium-hexafluorophosphate as respective examples of a molecular and an ionic liquid. This instrument and approach may prove useful for other studies of permittivity and conductivity where contact to the metal electrodes or to the ambient atmosphere needs to be avoided.

  1. Measurement of the nuclear multiplicity ratio for Ks0 hadronization at CLAS

    NASA Astrophysics Data System (ADS)

    Daniel, A.; Hicks, K.; Brooks, W. K.; Hakobyan, H.; Adhikari, K. P.; Adikaram, D.; Aghasyan, M.; Amarian, M.; Anghinolfi, M.; Avakian, H.; Baghdasaryan, H.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Bennett, R. P.; Biselli, A. S.; Bookwalter, C.; Briscoe, W. J.; Burkert, V. D.; Carman, D. S.; Casey, L.; Celentano, A.; Chandavar, S.; Cole, P. L.; Contalbrigo, M.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Dey, B.; Dickson, R.; Djalali, C.; Dodge, G. E.; Doughty, D.; Egiyan, H.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Gabrielyan, M. Y.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guo, L.; Hanretty, C.; Heddle, D.; Holtrop, M.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jawalkar, S. S.; Jo, H. S.; Joo, K.; Kalantarians, N.; Keller, D.; Khandaker, M.; Khetarpal, P.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Kubarovsky, V.; Kuleshov, S. V.; Kuznetsov, V.; Lu, H. Y.; MacGregor, I. J. D.; Mao, Y.; Markov, N.; Mayer, M.; McAndrew, J.; McKinnon, B.; Meyer, C. A.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Moutarde, H.; Munevar, E.; Nadel-Turonski, P.; Ni, A.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Paolone, M.; Pappalardo, L.; Paremuzyan, R.; Park, K.; Park, S.; Pasyuk, E.; Anefalos Pereira, S.; Phelps, E.; Pisano, S.; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Procureur, S.; Protopopescu, D.; Raue, B. A.; Ricco, G.; Rimal, D.; Ripani, M.; Rosner, G.; Rossi, P.; Sabatié, F.; Saini, M. S.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seraydaryan, H.; Sharabian, Y. G.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Stepanyan, S. S.; Stepanyan, S.; Strauch, S.; Taiuti, M.; Tang, W.; Taylor, C. E.; Tkachenko, S.; Ungaro, M.; Vernarsky, B.; Vineyard, M. F.; Voskanyan, H.; Voutier, E.; Watts, D. P.; Weinstein, L. B.; Weygand, D. P.; Wood, M. H.; Zana, L.; Zachariou, N.; Zhao, B.; Zhao, Z. W.

    2011-11-01

    The influence of cold nuclear matter on lepto-production of hadrons in semi-inclusive deep inelastic scattering is measured using the CLAS detector in Hall B at Jefferson Lab and a 5.014 GeV electron beam. We report the Ks0 multiplicity ratios for targets of C, Fe, and Pb relative to deuterium as a function of the fractional virtual photon energy z transferred to the Ks0 and the transverse momentum squared pT2 of the Ks0. We find that the multiplicity ratios for Ks0 are reduced in the nuclear medium at high z and low pT2, with a trend for the Ks0 transverse momentum to be broadened in the nucleus for large pT2.

  2. Measurement of the nuclear multiplicity ratio or image hadronization K0s at CLAS

    DOE PAGESBeta

    Daniel, A.; Hicks, K.; Brooks, W. K.; Hakobyan, H.; Adhikari, K. P.; Adikaram, D.; Aghasyan, M.; Amarian, M.; Anghinolfi, M.; Avakian, H.; et al

    2011-11-01

    The influence of cold nuclear matter on lepto-production of hadrons in semi-inclusive deep inelastic scattering is measured using the CLAS detector in Hall B at Jefferson Lab and a 5.014 GeV electron beam. We report the K0s multiplicity ratios for targets of C, Fe, and Pb relative to deuterium as a function of the fractional virtual photon energy z transferred to the K0sand the transverse momentum squared p2T of the K0s. We find that the multiplicity ratios for K0s are reduced in the nuclear medium at high z and low p2T, with a trend for the K0s transverse momentum tomore » be broadened in the nucleus for large p2T.« less

  3. Measurement of conductivity and permittivity on samples sealed in nuclear magnetic resonance tubes

    NASA Astrophysics Data System (ADS)

    Huang, W.; Angell, C. A.; Yarger, J. L.; Richert, R.

    2013-07-01

    We present a broadband impedance spectroscopy instrument designed to measure conductivity and/or permittivity for samples that are sealed in glass tubes, such as the standard 5 mm tubes used for nuclear magnetic resonance experiments. The calibrations and corrections required to extract the dielectric properties of the sample itself are outlined. It is demonstrated that good estimates of the value of dc-conductivity can be obtained even without correcting for the effects of glass or air on the overall impedance. The approach is validated by comparing data obtained from samples sealed in nuclear magnetic resonance tubes with those from standard dielectric cells, using glycerol and butylmethylimidazolium-hexafluorophosphate as respective examples of a molecular and an ionic liquid. This instrument and approach may prove useful for other studies of permittivity and conductivity where contact to the metal electrodes or to the ambient atmosphere needs to be avoided.

  4. Measurement of the true transverse nuclear magnetic resonance relaxation in the presence of field gradients

    NASA Astrophysics Data System (ADS)

    Mitchell, J.; Chandrasekera, T. C.; Gladden, L. F.

    2013-08-01

    A measure of the nuclear spin transverse relaxation time T2, as determined using the nuclear magnetic resonance Carr-Purcell Meiboom-Gill (CPMG) experiment, provides unique information characterizing the microstructure of porous media which are themselves ubiquitous across fields of petrophysics, biophysics, and chemical engineering. However, the CPMG measurement is sensitive to diffusion in large magnetic field gradients. Under such conditions an effective relaxation time T_{2,eff} is observed instead, described by a combination of relaxation and diffusion exponents. The relaxation exponent always varies as nte (where n is the number, and te is the temporal separation, of spin echoes). The diffusion exponent varies as nt_e^k, where 1 < k ⩽ 3, although the exact analytic form is often unknown. Here we present a general approach to separating the influence of relaxation and diffusion by utilizing a composite diffusion exponent. Any T_{2,eff} component with a power of k > 1 is removed to provide a measure of the true T2 relaxation time distribution from CPMG data acquired in the presence of a strong background gradient. We apply the technique to discriminate between the effects of relaxation and diffusion in porous media using catalysts and rocks as examples. The method is generally applicable to any CPMG measurements conducted in the presence of a static magnetic field gradient.

  5. On-site gamma-ray spectroscopic measurements of fission gas release in irradiated nuclear fuel.

    PubMed

    Matsson, I; Grapengiesser, B; Andersson, B

    2007-01-01

    An experimental, non-destructive in-pool, method for measuring fission gas release (FGR) in irradiated nuclear fuel has been developed. Using the method, a significant number of experiments have been performed in-pool at several nuclear power plants of the BWR type. The method utilises the 514 keV gamma-radiation from the gaseous fission product (85)Kr captured in the fuel rod plenum volume. A submergible measuring device (LOKET) consisting of an HPGe-detector and a collimator system was utilised allowing for single rod measurements on virtually all types of BWR fuel. A FGR database covering a wide range of burn-ups (up to average rod burn-up well above 60 MWd/kgU), irradiation history, fuel rod position in cross section and fuel designs has been compiled and used for computer code benchmarking, fuel performance analysis and feedback to reactor operators. Measurements clearly indicate the low FGR in more modern fuel designs in comparison to older fuel types. PMID:16949295

  6. Impact of the Fukushima nuclear accident on background radiation doses measured by control dosimeters in Japan.

    PubMed

    Romanyukha, Alexander; King, David L; Kennemur, Lisa K

    2012-05-01

    After the 9.0 magnitude earthquake and subsequent massive tsunami on 11 March 2011 in Japan, several reactors at the Fukushima Daiichi Nuclear Power Plant suffered severe damage. There was immediate participation of U.S. Navy vessels and other United States Department of Defense (DoD) teams that were already in the area at the time of the disaster or arrived shortly thereafter. The correct determination of occupational dose equivalent requires estimation of the background dose component measured by control dosimeters, which is subsequently subtracted from the total dose equivalent measured by personal dosimeters. The purpose of the control dosimeters is to determine the amount of radiation dose equivalent that has accumulated on the dosimeter from background or other non-occupational sources while they are in transit or being stored. Given the release of radioactive material and potential exposure to radiation from the Fukushima Daiichi Nuclear Power Plant and the process by which the U.S. Navy calculates occupational exposure to ionizing radiation, analysis of pre- and post-event control dosimeters is warranted. Several hundred historical dose records from the Naval Dosimetry Center (NDC) database were analyzed and compared with the post-accident dose equivalent data of control dosimeters. As result, it was shown that the dose contribution of the radiation and released radiological materials from the Fukushima nuclear accident to background radiation doses is less than 0.375 μSv d for shallow and deep photon dose equivalent. There is no measurable effect on neutron background exposure. The latter has at least two important conclusions. First, the NDC can use doses measured by control dosimeters at issuing sites in Japan for determination of personnel dose equivalents; second, the dose data from control dosimeters prior to and after the Fukushima accident may be used to assist in dose reconstruction of non-radiological (non-badged) personnel at these locations

  7. Nuclear magnetic resonance measurement of ammonia diffusion in dense solid-liquid slurries. Revision 1

    SciTech Connect

    Bobroff, S.; Phillips, R.J.; Shekarriz, A.

    1998-01-01

    The flammability and toxicity of ammonia released from the nuclear waste tanks at Hanford have been the subject of several recent studies. These releases may occur episodically, such as the buoyant plume releases occurring in various double-shell tanks (DSTs); gradually through the surface of the waste; or from the partially saturated saltcakes in the single-shell tanks during salt-well pumping. The diffusion of ammonium ions in aqueous solutions was measured by nuclear magnetic resonance (NMR) using the pulsed field gradient (PFG) method. The ammonium ions were obtained from aqueous solutions of ammonium chloride, ammonium sulfate, ammonium bicarbonate, and ammonium hydroxide. The translational diffusion of the ammonium ions was determined by measuring the diffusion of nitrogen nuclei in solution. Results showed that the ammonium diffusion coefficient can be measured in aqueous solutions with concentrations as low as 20 {times} 10{sup {minus}3} {und M}. Typical values measured for the diffusion coefficient of the ammonium ion are 2 {times} 10{sup {minus}5} cm{sup 2}/s ({+-}10%), similar to the values found for pure water. Due to the effect of the solution pH upon the NMR relaxation parameters for {sup 14}N, measurements are constrained to pH values below 8.5. However, {sup 15}N labeled ammonia is less sensitive to the solution pH, extending the measurement range to pH of 9.5. The results show that the solution viscosity has a measurable impact on the diffusion coefficient. The diffusion coefficient is almost inversely proportional to the relative viscosity of the solution, irrespective of how the viscosity is increased. Further, a randomly-packed porous bed of 200 {micro}m PMMA resulted in a reduction of {approximately} 30% in the diffusion coefficient as a result of hindered diffusion.

  8. Nuclear magnetic resonance measurement of ammonia diffusion in dense solid-liquid slurries

    SciTech Connect

    Bobroff, S.; Phillips, R.J.; Shekarriz, A.

    1997-09-01

    The diffusion of ammonium ions in aqueous solutions was measured by nuclear magnetic resonance (NMR) using the pulsed field gradient (PFG) method. The ammonium ions were obtained from aqueous solutions of ammonium chloride, ammonium sulfate, ammonium bicarbonate, and ammonium hydroxide. The translation diffusion of the ammonium ions was determined by measuring the diffusion of nitrogen nuclei ({sup 14}N and {sup 15}N) in solution. Our results showed that the ammonium diffusion coefficient can be measured in aqueous solutions with concentrations as low as 20 x 10{sup -3} M. Typical values measured for the diffusion coefficient of the ammonium ion are 2 x 10{sup -5} cm{sup 2/s} ({+-}10%), similar to the values found for pure water. Due to the effect of the solution pH upon the NMR relaxation parameters for {sup 14}N, measurements are constrained to pH values below 8.5. However, {sup 15}N labeled ammonium is less sensitive to the solution pH, extending the measurement range to pH of 9.5. Diffusion measurements were conducted with solutions of varying viscosity and porosity. The results show that the solution viscosity has a measureable impact on the diffusion coefficient. The diffusion coefficient is almost inversely proportional to the relative viscosity of the solution, irrespective of how the viscosity is increased. Further, a randomly-packed porous bed of 200 mm PMMA resulted in a reduction of {approximately}30% in the diffusion coefficient as a result of hindered diffusion.

  9. Cooperative measures to support the Indo-Pak Agreement Reducing Risk from Accidents Relating to Nuclear Weapons.

    SciTech Connect

    Mishra, Sitakanta; Ahmed, Mansoor

    2014-04-01

    In 2012, India and Pakistan reaffirmed the Agreement on Reducing the Risk from Accidents Relating to Nuclear Weapons. Despite a history of mutual animosity and persistent conflict between the two countries, this agreement derives strength from a few successful nuclear confidence building measures that have stood the test of time. It also rests on the hope that the region would be spared a nuclear holocaust from an accidental nuclear weapon detonation that might be misconstrued as a deliberate use of a weapon by the other side. This study brings together two emerging strategic analysts from South Asia to explore measures to support the Agreement and further develop cooperation around this critical issue. This study briefly dwells upon the strategic landscape of nuclear South Asia with the respective nuclear force management structures, doctrines, and postures of India and Pakistan. It outlines the measures in place for the physical protection and safety of nuclear warheads, nuclear materials, and command and control mechanisms in the two countries, and it goes on to identify the prominent, emerging challenges posed by the introduction of new weapon technologies and modernization of the respective strategic forces. This is followed by an analysis of the agreement itself leading up to a proposed framework for cooperative measures that might enhance the spirit and implementation of the agreement.

  10. 10 CFR 50.60 - Acceptance criteria for fracture prevention measures for lightwater nuclear power reactors for...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Acceptance criteria for fracture prevention measures for lightwater nuclear power reactors for normal operation. 50.60 Section 50.60 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Issuance, Limitations, and Conditions of Licenses and Construction Permits...

  11. Demonstration of a transmission nuclear resonance fluorescence measurement for a realistic radioactive waste canister scenario

    NASA Astrophysics Data System (ADS)

    Angell, C. T.; Hajima, R.; Hayakawa, T.; Shizuma, T.; Karwowski, H. J.; Silano, J.

    2015-03-01

    Transmission nuclear resonance fluorescence (NRF) is a promising method for precision non-destructive assay (NDA) of fissile isotopes-including 239Pu-in spent fuel while inside a storage canister. The assay, however, could be confounded by the presence of overlapping resonances from competing isotopes in the canister. A measurement is needed to demonstrate that transmission NRF is unaffected by the shielding material. To this end, we carried out a transmission NRF measurement using a mono-energetic γ-ray beam on a proxy target (Al) and absorbing material simulating a realistic spent fuel storage canister. Similar amounts of material as would be found in a possible spent fuel storage canister were placed upstream: concrete, stainless steel (SS 304), lead (as a proxy for U), and water. An Al absorption target was also used as a reference. These measurements demonstrated that the canister material should not significantly influence the non-destructive assay.

  12. Electronic Magnetization of a Quantum Point Contact Measured by Nuclear Magnetic Resonance

    NASA Astrophysics Data System (ADS)

    Kawamura, Minoru; Ono, Keiji; Stano, Peter; Kono, Kimitoshi; Aono, Tomosuke

    2015-07-01

    We report an electronic magnetization measurement of a quantum point contact (QPC) based on nuclear magnetic resonance (NMR) spectroscopy. We find that NMR signals can be detected by measuring the QPC conductance under in-plane magnetic fields. This makes it possible to measure, from Knight shifts of the NMR spectra, the electronic magnetization of a QPC containing only a few electron spins. The magnetization changes smoothly with the QPC potential barrier height and peaks at the conductance plateau of 0.5 ×2 e2/h . The observed features are well captured by a model calculation assuming a smooth potential barrier, supporting a no bound state origin of the 0.7 structure.

  13. Precision measurements of nuclear CR energy spectra and composition with the AMS-02 experiment

    NASA Astrophysics Data System (ADS)

    Fiandrini, E.

    2016-05-01

    The Alpha Magnetic Spectrometer 02 (AMS-02) is a large acceptance high-energy physics experiment operating since May 2011 on board the International Space Station. More than 60 billion events have been collected by the instrument in the first four years of operation. AMS-02 offers a unique opportunity to study the Cosmic Rays (CRs) since it measures the spectra of all the species simultaneously. We report on the precision measurements of primary and secondary nuclear spectra, in the GeV-TeV energy interval. These measurements allow for the first time a detailed study of the spectral index variation with rigidity providing a new insight on the origin and propagation of CR.

  14. Study on signal intensity of low field nuclear magnetic resonance via an indirect coupling measurement

    NASA Astrophysics Data System (ADS)

    Jiang, Feng-Ying; Wang, Ning; Jin, Yi-Rong; Deng, Hui; Tian, Ye; Lang, Pei-Lin; Li, Jie; Chen, Ying-Fei; Zheng, Dong-Ning

    2013-04-01

    We carry out an ultra-low-field nuclear magnetic resonance (NMR) experiment based on high-Tc superconducting quantum interference devices (SQUIDs). The measurement field is in a micro-tesla range (~10 μT-100 μT) and the experiment is conducted in a home-made magnetically-shielded-room (MSR). The measurements are performed by the indirect coupling method in which the signal of nuclei precession is indirectly coupled to the SQUID through a tuned copper coil transformer. In such an arrangement, the interferences of applied measurement and polarization field to the SQUID sensor are avoided and the performance of the SQUID is not destroyed. In order to compare the detection sensitivity obtained by using the SQUID with that achieved using a conventional low-noise-amplifier, we perform the measurements using a commercial room temperature amplifier. The results show that in a wide frequency range (~1 kHz-10 kHz) the measurements with the SQUID sensor exhibit a higher signal-to-noise ratio. Further, we discuss the dependence of NMR peak magnitude on measurement frequency. We attribute the reduction of the peak magnitude at high frequency to the increased field inhomogeneity as the measurement field increases. This is verified by compensating the field gradient using three sets of gradient coils.

  15. Measuring the Nuclear Magnetic Octupole Moment of a Single Trapped Barium-137 Ion

    NASA Astrophysics Data System (ADS)

    Kleczewski, Adam; Fortson, Norval; Blinov, Boris

    2009-05-01

    Recent measurements of hyperfine structure in the cesium-133 atom resolved a nuclear magnetic octupole moment φ much larger than expected from the nuclear shell model[1]. To explore this issue further, we are undertaking an experiment to measure the hyperfine structure in the 5D manifold of a single trapped barium-137 ion which, together with reliable calculations in alkali-like Ba^+, should resolve φ with sensitivity better than the shell model value [2]. We use a TmHo:YLF laser tuned to 2051 nm and a fiber laser tuned to 1762 nm to drive the 6S1/2 to 5D3/2 and 6S1/2 to 5D5/2 electric quadrupole transitions. These lasers allow us to selectively populate any hyperfine sub-level in the 5D manifold. We will then perform RF spectroscopy on the 5D states to make a precision measurement of the hyperfine frequency intervals. We report on the development of the laser and RF spectroscopy systems. [1] V. Gerginov, A. Derevianko, and C. E. Tanner, Phys. Rev. Lett. 91, 072501 [2] K. Beloy, A. Derevianko, V. A. Dzuba, G. T. Howell, B. B. Blinov, E. N. Fortson, arXiv:0804.4317v1 [physics.atom-ph] 28 Apr 2008

  16. Some possible applications of measurements on mu mesons to nuclear safeguards, nonproliferation, and arms control activities

    SciTech Connect

    Kane, W.R.; Vanier, P.E.

    1997-10-01

    In the nuclear safeguards and arms control areas, well-developed methodologies exist for determining the properties of nuclear materials via measurements of the gamma rays and neutrons emitted from these materials, or in the arms control area, by the use of radiography. In certain favorable instances, it may by feasible to perform comparable measurements with the use of a ubiquitous, naturally-occurring radiation--cosmic ray mu mesons (muons). At the earth`s surface these charged particles have a broad energy distribution peaking at about 500 MeV with a flux of approximately 10{sup {minus}2}/cm{sup 2}-sec-steradian. In traversing matter, muons lose energy at a rate of approximately 2 MeV/gram almost independent of atomic number. Muons can readily be detected by either plastic scintillators or wire planes. While the flux is small, a scintillator of one meter area, for example, will register about 20,000 events/min. these particles should have utility in the detection and imaging of objects with sectional densities of a few hundred grams/cm{sup 2}. The degree of intrusiveness of the imaging can be controlled through the detector configuration. Some possible applications include: (1) mass measurements on large UF{sub 6} cylinders, (2) determination of the size of treaty-limited objects, e.g., missiles, in rail cars or other containment; (3) verification of single or multiple warheads or components; (4) the detection of concealed, underground cavities. Examples will be presented.

  17. Precise measurement of the nuclear dependence of the EMC effect at large x

    NASA Astrophysics Data System (ADS)

    Daniel, Aji

    Experiment E03-103, carried out in Hall C at the Thomas Jefferson National Accelerator Facility, measuring inclusive electron scattering cross sections from nuclear targets over a broad range of x (0.3 < x < 1) up to Q2 ≈ 8 GeV 2. The bulk of the data were taken at a beam energy of 5.8 GeV, with beam currents ranging from 30 to 80 muA. This dissertation describes the experiment in detail, and presents the extracted EMC ratios for the cryogenic targets 3He, 4He and solid targets Be, C, Cu, and Au. Our data provide the first measurement of the EMC effect in 3He at x > 0.4, and improve the known precision of the existing measurements of the effect in 4He and other nuclear targets at large x. The data have also been analyzed in terms of the structure function FA2 to examine the scaling of the inelastic scattering in x and xi.

  18. Recent Developments in Nuclear Data Measurement capabilities at the Gaerttner LINAC Center at RPI

    NASA Astrophysics Data System (ADS)

    Danon, Y.; Daskalakis, A.; McDermott, B.; Thompson, N.; Youmans, A.; Block, R.; Barry, D.; Epping, B.; Leinweber, G.; Rapp, M.; Donovan, T.

    2016-03-01

    The Gaerttner LINAC Center at RPI uses a 60 MeV electron linear accelerator to produce short pulses of neutrons with duration of 5-5000 ns. The main research thrust at the Center is nuclear data for nuclear reactors and criticality safety applications. The Center includes several setups for time-of-flight measurements including neutron transmission, capture and scattering detectors, and a lead slowing-down spectrometer. Experiments were designed to produce neutron interaction cross sections that cover the energy range of 0.01 eV to 20 MeV. Recently added experiments include: setups for keV and fast neutron transmission, a C6D6 detector array for keV neutron capture measurements, and a fast neutron scattering system. Results discussed here include fast neutron scattering and angular distributions for natFe, iron capture measurements for incident neutrons from 1 keV to 2 MeV, fast neutron transmission through W and H2O samples, and keV transmission through Mo isotopes.

  19. Measurement of the nuclear electromagnetic cascade development in glass at energies above 200 GeV

    NASA Technical Reports Server (NTRS)

    Gillespie, C. R.; Huggett, R. W.; Humphreys, D. R.; Jones, W. V.; Levit, L. B.

    1971-01-01

    The longitudinal development of nuclear-electromagnetic cascades with energies greater than 200 GeV was measured in a low-Z (glass) absorber. This was done in the course of operating an ionization spectrometer at mountain altitude in an experiment to study the properties of gamma rays emitted from individual interactions at energies around 10,000 GeV. The ionization produced by a cascade is sampled by 20 sheets of plastic scintillator spaced uniformly in depth every 2.2 radiation lengths. Adjacent pairs of scintillators are viewed by photomultipliers which measure the mean ionization produced by an individual cascade in 10 layers each 1.1 interaction length (4.4 radiation lengths) thick. The longitudinal development of the cascades was measured for about 250 cascades having energies ranging from 200 GeV to 2500 GeV. The observations are compared with the predictions of calculations made for this specific spectrometer using a three-dimensional Monte Carlo model of the nuclear-electromagnetic cascade.

  20. Integrated Geophysical Measurements for Bioremediation Monitoring: Combining Spectral Induced Polarization, Nuclear Magnetic Resonance and Magnetic Methods

    SciTech Connect

    Keating, Kristina; Slater, Lee; Ntarlagiannis, Dimitris; Williams, Kenneth H.

    2015-02-24

    This documents contains the final report for the project "Integrated Geophysical Measurements for Bioremediation Monitoring: Combining Spectral Induced Polarization, Nuclear Magnetic Resonance and Magnetic Methods" (DE-SC0007049) Executive Summary: Our research aimed to develop borehole measurement techniques capable of monitoring subsurface processes, such as changes in pore geometry and iron/sulfur geochemistry, associated with remediation of heavy metals and radionuclides. Previous work has demonstrated that geophysical method spectral induced polarization (SIP) can be used to assess subsurface contaminant remediation; however, SIP signals can be generated from multiple sources limiting their interpretation value. Integrating multiple geophysical methods, such as nuclear magnetic resonance (NMR) and magnetic susceptibility (MS), with SIP, could reduce the ambiguity of interpretation that might result from a single method. Our research efforts entails combining measurements from these methods, each sensitive to different mineral forms and/or mineral-fluid interfaces, providing better constraints on changes in subsurface biogeochemical processes and pore geometries significantly improving our understanding of processes impacting contaminant remediation. The Rifle Integrated Field Research Challenge (IFRC) site was used as a test location for our measurements. The Rifle IFRC site is located at a former uranium ore-processing facility in Rifle, Colorado. Leachate from spent mill tailings has resulted in residual uranium contamination of both groundwater and sediments within the local aquifer. Studies at the site include an ongoing acetate amendment strategy, native microbial populations are stimulated by introduction of carbon intended to alter redox conditions and immobilize uranium. To test the geophysical methods in the field, NMR and MS logging measurements were collected before, during, and after acetate amendment. Next, laboratory NMR, MS, and SIP measurements

  1. Modeling and Simulation Approaches to Developing Human Performance Measures in Nuclear Industry

    SciTech Connect

    Bruce P. Hallbert; Jeffrey C. Joe; Molly J. Keefe; Julius J. Persensky

    2007-08-01

    Human performance is a key component to the safe operation of nuclear power plants. Further, human performance is quite variable, and while some variability may be random, much of it may be attributed to factors that are difficult to assess. There is a need to identify and assess aspects of human performance that relate to plant safety and to develop measures that can be used to successfully assess human performance for purposes of research that can lead to technical basis for developing human factors review criteria.

  2. Measuring nuclear transparency from exclusive vector meson production in lepton-nucleus scattering

    SciTech Connect

    Fang, G.Y.

    1994-04-01

    Preliminary results on the measurement of nuclear transparencies from exclusive {rho}{sup 0} meson production from E665 at Fermilab are reported. The data were collected on hydrogen, deuterium, carbon, calcium, and lead targets with a mean beam energy of 470 GeV. Increases in the transparencies are observed in both coherent and incoherent production channels as the virtuality of the photon increases, as expected of color transparency. Ideas of systematic studies of color transparency in exclusive vector meson production at CEBAF are discussed.

  3. Sensors Synergistic With Nature For In-pile Nuclear Reactor Measurements

    SciTech Connect

    James A. Smith; Dale K. Kotter; Steven L. Garrett; Randall A. Ali

    2012-10-01

    To be able to evolve fuel and structural microstructure within a nuclear power reactor in an engineered manner, an effective extreme environment sensor must exist. The development of sensor technology for nondestructive and nonintrusive measurements in harsh environments is a very active field. However most of the effort has been in adapting existing sensing technology to meet the harsh environmental requirements. A different approach is being presented. The fundamental question that we are trying to answer is how do we take advantage of the harsh environment and maintain synergy between the sensor and the environment. This paper will discuss the synergistic senor being developed that takes advantage of the harsh environments.

  4. Measuring Human Performance in Simulated Nuclear Power Plant Control Rooms Using Eye Tracking

    SciTech Connect

    Kovesdi, Casey Robert; Rice, Brandon Charles; Bower, Gordon Ross; Spielman, Zachary Alexander; Hill, Rachael Ann; LeBlanc, Katya Lee

    2015-11-01

    Control room modernization will be an important part of life extension for the existing light water reactor fleet. As part of modernization efforts, personnel will need to gain a full understanding of how control room technologies affect performance of human operators. Recent advances in technology enables the use of eye tracking technology to continuously measure an operator’s eye movement, which correlates with a variety of human performance constructs such as situation awareness and workload. This report describes eye tracking metrics in the context of how they will be used in nuclear power plant control room simulator studies.

  5. Measurement of nuclear magnetic dipole—dipole couplings in magic angle spinning NMR

    NASA Astrophysics Data System (ADS)

    Tycko, Robert; Dabbagh, Gary

    1990-10-01

    We describe a method for measuring nuclear magnetic dipole—dipole couplings in NMR spectra of solids undergoing rapid magic angle spinning (MAS). We show in theory, simulations, and experiments that the couplings, which are averaged out by MAS alone, can be recovered by applying simple resonant radiofrequency pulse sequences in synchrony with the sample rotation. Experimental 13C dipolar powder pattern spectra of polycrystalline ( 13CH 3) 2C(OH)SO 3Na obtained in a two-dimensional experiment based on this method are presented. The method provides a means of determining internuclear distances in polycrystalline and noncrystalline solids while retaining the high resolution and sensitivity afforded by MAS.

  6. Measurement of the 14N nuclear quadrupole resonance frequencies by the solid effect

    NASA Astrophysics Data System (ADS)

    Seliger, J.; Žagar, V.

    2008-07-01

    1H- 14N nuclear quadrupole double resonance using magnetic field cycling between high and low magnetic field and solid effect in the low magnetic field is analyzed in details. The transition probabilities per unit time for the solid-effect transitions are calculated. The double resonance spectra are calculated in the limiting cases of fast and slow nitrogen spin-lattice relaxation. The double resonance spectra are measured in histamine and quinolinic acid. The experimental spectra are analyzed and the 14N NQR frequencies are determined.

  7. Measuring radon in air, soil and water—an introduction to nuclear physics for schools

    NASA Astrophysics Data System (ADS)

    Johansson, K. E.; Nilsson, Ch; Wachtmeister, S.

    2007-05-01

    With the radon measurement activities at Stockholm House of Science, nuclear and experimental physics is introduced in a way that attracts the attention and interest of the students. These projects give the students the opportunity to use mobile detectors, either in their school, in the House of Science or in their homes. During 2006, 34 radon experiments were organized for school classes or groups of students. There were 21 shorter activities, ten one-day projects and three projects lasting for one or more weeks. Because of the popularity of the radon project, it will be extended with the introduction of more mobile detectors.

  8. Highly Depleted Ethane and Slightly Depleted Methanol in Comet 21P/Giacobini-Zinner: Application of Empirical g-factors for CH3OH near 50 K

    NASA Astrophysics Data System (ADS)

    DiSanti, Michael A.; Bonev, B. P.; Villanueva, G. L.; Mumma, M. J.

    2012-10-01

    We report results from high resolution (λ/Δλ 24,000) infrared spectra of Comet 21P/Giacobini-Zinner (21P/GZ) using NIRSPEC at Keck II on UT 2005 June 03, approximately one month before perihelion. We simultaneously sampled emissions from the ν7 band of C2H6, the ν2 and ν3 bands of CH3OH, and several hot bands of H2O, permitting a direct measure of parent volatile abundances in 21P/GZ. Our production rate for H2O was consistent with that measured from previous apparitions as retrieved from optical, infrared, and mm-wavelength observations. Our analysis of C2H6 confirmed its previously reported strong depletion from IR observations during the 1998 apparition [1,2], similar to the depletion of C2 in 21P/GZ known from optical studies [3]. For CH3OH, we applied our recently published quantum model for ν3 [4], obtaining Trot consistent with that for H2O ( 50 K) and a high abundance ratio CH3OH/C2H6 ( 9). We observed similar Trot and CH3OH/C2H6 in Comet 8P/Tuttle [5,6], and used these to produce effective (empirical) ν2 g-factors for 157 lines [7]. Application of our empirical ν2 model to 21P/GZ provided a production rate consistent with that from ν3, and an abundance ratio CH3OH/H2O in agreement with that measured previously [1,8]. We present a summary of our results for 21P/GZ and compare with abundances obtained for other Jupiter family comets. Our study provides the first measure of primary volatile production rates for any JFC over multiple apparitions using high resolution ground-based IR spectroscopy. We acknowledge support from the NASA Planetary Atmospheres, Planetary Astronomy, and Astrobiology Programs and from the NSF Astronomy and Astrophysics Research Grants Program. References [1] Weaver et al. 1999 Icarus 142:482 [2] Mumma et al. 2000 ApJ 531:L155 [3] A’Hearn et al. 1995 Icarus 118:223 [4] Villanueva et al. 2012 ApJ 747:37 [5] Bonev et al. 2008 ApJ 680:L61 [6] Boehnhardt et al. 2008 ApJ 683:L71 [7] DiSanti et al. 2012 ApJ (in press) [8] Biver

  9. Measuring 19F(α,n) with VANDLE for Nuclear Safeguards

    NASA Astrophysics Data System (ADS)

    Peters, William; Clement, R. C. C.; Smith, M. S.; Pain, S. D.; Thompson, S.; Cizewski, J. A.; Reingold, C.; Manning, B.; Burcher, S.; Bardayan, D. W.; Tan, W.-P.; Stech, E.; Smith, M. K.; Smith, K.; Avetisyan, R.; Long, A.; Battaglia, A.; Marley, S.; Gyurjinyan, A.; Ilyushkin, S.; O'Malley, P. D.; Madurga, M.; Paulauskas, S. V.; Taylor, S.; Febbraro, M.

    2014-09-01

    UF6 is used in many parts of the Uranium Fuel Cycle, and various techniques are used by nonproliferation agencies to monitor and account for the material. One of the most promising non-destructive assay (NDA) methods consists of measuring gross neutron rates induced by uranium-decay alpha particles reacting with the fluorine and emitting a neutron. This method, however, currently lacks reliable nuclear data on the 19F(α,n) reaction cross section to determine an accurate neutron yield rate for a given sample of UF6. We have used the Versatile Array of Neutron Detectors at Low Energy (VANDLE) to measure the cross section and coincident neutron spectrum over an energy range pertinent to NDA in a two part experiment: First at Notre Dame with a LaF3 target and a pulsed alpha-particle beam, and second at ORNL with a windowless He-gas target and a 19F beam. The motivation for this measurement and preliminary results will be presented. UF6 is used in many parts of the Uranium Fuel Cycle, and various techniques are used by nonproliferation agencies to monitor and account for the material. One of the most promising non-destructive assay (NDA) methods consists of measuring gross neutron rates induced by uranium-decay alpha particles reacting with the fluorine and emitting a neutron. This method, however, currently lacks reliable nuclear data on the 19F(α,n) reaction cross section to determine an accurate neutron yield rate for a given sample of UF6. We have used the Versatile Array of Neutron Detectors at Low Energy (VANDLE) to measure the cross section and coincident neutron spectrum over an energy range pertinent to NDA in a two part experiment: First at Notre Dame with a LaF3 target and a pulsed alpha-particle beam, and second at ORNL with a windowless He-gas target and a 19F beam. The motivation for this measurement and preliminary results will be presented. This work is funded in part by NSF Grant 1068192, DOE Office of Science, and the NNSA Office of Defense Nuclear

  10. Neutron Radiography and Fission Mapping Measurements of Nuclear Materials with Varying Composition and Shielding

    SciTech Connect

    Mullens, James Allen; McConchie, Seth M; Hausladen, Paul; Mihalczo, John T; Grogan, Brandon R; Sword, Eric D

    2011-01-01

    Neutron radiography and fission mapping measurements were performed on four measurement objects with varying composition and shielding arrangements at the Idaho National Laboratory's Zero Power Physics Reactor (ZPPR) facility. The measurement objects were assembled with ZPPR reactor plate materials comprising plutonium, natural uranium, or highly enriched uranium and were presented as unknowns for characterization. As a part of the characterization, neutron radiography was performed using a deuterium-tritium (D-T) neutron generator as a source of time and directionally tagged 14 MeV neutrons. The neutrons were detected by plastic scintillators placed on the opposite side of the object, using the time-correlation-based data acquisition of the Nuclear Materials Identification System developed at Oak Ridge National Laboratory. Each object was measured at several rotations with respect to the neutron source to obtain a tomographic reconstruction of the object and a limited identification of materials via measurement of the neutron attenuation. Large area liquid scintillators with pulse shape discrimination were used to detect the induced fission neutrons. A fission site map reconstruction was produced by time correlating the induced fission neutrons with each tagged neutron from the D-T neutron generator. This paper describes the experimental configuration, the ZPPR measurement objects used, and the neutron imaging and fission mapping results.

  11. Measurement of plutonium in spent nuclear fuel by self-induced x-ray fluorescence

    SciTech Connect

    Hoover, Andrew S; Rudy, Cliff R; Tobin, Steve J; Charlton, William S; Stafford, A; Strohmeyer, D; Saavadra, S

    2009-01-01

    Direct measurement of the plutonium content in spent nuclear fuel is a challenging problem in non-destructive assay. The very high gamma-ray flux from fission product isotopes overwhelms the weaker gamma-ray emissions from plutonium and uranium, making passive gamma-ray measurements impossible. However, the intense fission product radiation is effective at exciting plutonium and uranium atoms, resulting in subsequent fluorescence X-ray emission. K-shell X-rays in the 100 keV energy range can escape the fuel and cladding, providing a direct signal from uranium and plutonium that can be measured with a standard germanium detector. The measured plutonium to uranium elemental ratio can be used to compute the plutonium content of the fuel. The technique can potentially provide a passive, non-destructive assay tool for determining plutonium content in spent fuel. In this paper, we discuss recent non-destructive measurements of plutonium X-ray fluorescence (XRF) signatures from pressurized water reactor spent fuel rods. We also discuss how emerging new technologies, like very high energy resolution microcalorimeter detectors, might be applied to XRF measurements.

  12. Measurement of Nuclear Recoils in the CDMS II Dark Matter Search

    NASA Astrophysics Data System (ADS)

    Fallows, Scott M.

    The Cryogenic Dark Matter Search (CDMS) experiment is designed to directly detect elastic scatters of weakly-interacting massive dark matter particles (WIMPs), on target nuclei in semiconductor crystals composed of Si and Ge. These scatters would occur very rarely, in an overwhelming background composed primarily of electron recoils from photons and electrons, as well as a smaller but non-negligible background of WIMP-like nuclear recoils from neutrons. The CDMS~II generation of detectors simultaneously measure ionization and athermal phonon signals from each scatter, allowing discrimination against virtually all electron recoils in the detector bulk. Pulse-shape timing analysis allows discrimination against nearly all remaining electron recoils taking place near detector surfaces. Along with carefully limited neutron backgrounds, this experimental program allowed for "background-free'' operation of CDMS~II at Soudan, with less than one background event expected in each WIMP-search analysis. As a result, exclusionary upper-limits on WIMP-nucleon interaction cross section were placed over a wide range of candidate WIMP masses, ruling out large new regions of parameter space. These results, like any others, are subject to a variety of systematic effects that may alter their final interpretations. A primary focus of this dissertation will be difficulties in precisely calibrating the energy scale for nuclear recoil events like those from WIMPs. Nuclear recoils have suppressed ionization signals relative to electron recoils of the same recoil energy, so the response of the detectors is calibrated differently for each recoil type. The overall normalization and linearity of the energy scale for electron recoils in CDMS~II detectors is clearly established by peaks of known gamma energy in the ionization spectrum of calibration data from a 133Ba source. This electron-equivalent keVee) energy scale enables calibration of the total phonon signal (keVt) by enforcing unity

  13. The AMS Measurements and Its Applications in Nuclear Physics at China Institute of Atomic Energy (CIAE)

    SciTech Connect

    Jiang Shan; Shen Hongtao; He Ming; Dong Kejun; He Guozhu; Wang Xianggao; Yuan Jian; Wang Wei; Wu Shaoyong; Ruan Xiangdong; Wu Weimin

    2010-05-12

    Accelerator Mass Spectrometry (AMS), initiated in late 1970s at McMaster university based on the accelerator and detector technique, has long been applied in the studies on archaeology, geology, and cosmology, as a powerful tool for isotope dating. The advantages of AMS in the analysis of rare nuclides by direct counting of the atoms, small sample size and relatively free from the interferences of molecular ions have been well documented. This paper emphasizes that AMS can not only be used for archaeology, geology, environment, biology and so on, but also served as a unique tool for nuclear physics research. In this paper, the determination of the half-lives of {sup 79}Se, the measurements of the cross-sections of {sup 93}Nb(n,2n){sup 92g}Nb and {sup 238}U(n,3n){sup 236}U reactions, the detection and determination of ultratrace impurities in neutrino detector materials, and the measurement of the fission product nuclide {sup 126}Sn, are to be introduced, as some of examples of AMS applications in nuclear research conducted in AMS lab of China Institute of Atomic Energy. Searching for superheavy nuclides by using AMS is being planned.

  14. Precision measurement of quenching factors for low-energy nuclear recoils at TUNL

    NASA Astrophysics Data System (ADS)

    Rich, Grayson; Barbeau, Phil; Howell, Calvin; Karwowski, Hugon

    2014-03-01

    With detector technologies becoming increasingly sensitive to exotic events, a thorough understanding of signal yield as a function of deposited energy is required for appropriate interpretation of results from cutting edge detector systems. Elastic neutron scattering is a probe which has been used to mimic the nuclear recoils which may be produced in detection media by light-WIMP interactions or coherent neutrino-nucleus scattering (CNS). We have built at the Triangle Universities Nuclear Laboratory (TUNL) a facility which produces pulsed, collimated, low-energy, quasi-monoenergetic neutron beams using the 7Li(p,n) reaction, resulting in fluxes of ~ 1 neutrons / (s . cm2) at ~90 cm from the neutron-production target. The first precision results from this facility are reported for ultra-low-energy recoils in NaI(Tl) and CsI(Na) and future plans are outlined, including measurements on candidate materials for a CNS detector that can potentially be fielded at the Spallation Neutron Source of Oak Ridge National Laboratory as a part the Coherent Scatter Initiative (CSI). We discuss the implications of new, precise measurements of quenching factors on neutrino detectors and on current- and next-generation light-WIMP searches, particularly the DAMA experiment.

  15. Oxygen isotopic measurements by secondary ion mass spectrometry in uranium oxide microparticles: a nuclear forensic diagnostic.

    PubMed

    Tamborini, G; Phinney, D; Blidstein, O; Betti, M

    2002-12-01

    To exploit oxygen isotopic measurement by SIMS as a diagnostic tool in nuclear forensics, the magnitude and reproducibility of 0-isotope instrumental mass discrimination for O-isotope standards in the SIMS laboratory at the Institute for Transuranium Elements has been evaluated. Tests for matrix-dependent discrimination effects on three different O-isotope standards with substantially different matrix compositions have been performed. The results were checked by an interlaboratory comparison of O-isotope discrimination with those obtained in the SIMS laboratory at the Lawrence Livermore National Laboratory on two standards. The results from the two laboratories are in very good agreement, indicating statistically indistinguishable instrumental mass discrimination factors for 180/160 ratios on the Cameca 6f and 3f, when the analyses are performed under the experimental conditions described. The 2sigma(mean) uncertainties of these factors are in the range of 0.3-0.9%. In accordance with the tested methodology, 0-isotope compositions were measured in three particulate uranium oxide samples of nuclear forensics interest. PMID:12498207

  16. The Measurement of Helium Isotopes to Demonstrate Solid State Nuclear Processes.

    NASA Astrophysics Data System (ADS)

    McKubre, Michael C. H.; Tanzella, Francis L.; Tripodi, Paolo; Violante, Vittorio

    2001-03-01

    We have observed numerous anomalies in carefully performed experimental studies of D/Pd and H/Pd systems, including quantitative correlation between an apparent nuclear product, ^4He, and the presence of an unexplained heat release. The problem of potential contamination from the high ambient ^4He background level (volumetric atmospheric concentration≈5.22 ppm) requires the use of careful experiment isolation and gas handling procedures. These difficulties can be significantly reduced by an accurate and sensitive measurement of the ^3He/^4He ratio R which is small, stable and well known in the ambient atmospheric background (R≈1.38x10^-^6). Significant decreases in R can be reliably interpreted as being due to selective production of ^4He. Increases in R most likely result from production of ^3He, or decay of ^3H. A facility is being established at SRI working in conjunction with ENEA-Frascati, to measure sensitively and accurately ^3He and ^4He concentrations in gas and solid samples obtained from experiments performed in hydrogen and deuterium environments, previously shown, believed, suspected or expected to exhibit characteristics of low energy nuclear processes.

  17. Karyotype characterization and nuclear DNA content measurement in Bromeliaceae: state of the art and future perspectives.

    PubMed

    Nunes, Andrei C P; Clarindo, Wellington R

    2014-12-01

    In Bromeliaceae, cytogenetic and flow cytometry analyses have been performed to clarify systematic and evolutionary aspects. Karyotyping approaches have shown the relatively high chromosome number, similar morphology and small size of the chromosomes. These facts have prevented a correct chromosome counting and characterization. Authors have established a basic chromosome number of x = 25 for Bromeliaceae. Recently, one karyomorphological analysis revealed that x = 25 is no longer the basic chromosome number, whose genome may have a polyploid origin. Besides cytogenetic characterization, the 2C DNA content of bromeliads has been measured. Nuclear DNA content has varied from 2C = 0.60 to 2C = 3.34 picograms. Thus, in relation to most angiosperms, the 2C DNA content of Bromeliaceae species as well as their chromosome size can be considered relatively small. In spite of some advances, cytogenetic and flow cytometry data are extremely scarce in this group. In this context, this review reports the state of the art in karyotype characterization and nuclear DNA content measurement in Bromeliaceae, emphasizing the main problems and suggesting prospective solutions and ideas for future research. PMID:25590721

  18. Nuclear Alignment in Projectile Fragmentation as a Tool for Moment Measurements

    SciTech Connect

    Georgiev, G.; Matea, I.; Oliveira Santos, F. de; Lewitowicz, M.; Daugas, J.M.; Belier, G.; Goutte, H.; Meot, V.; Roig, O.; Astabatyan, R.; Lukyanov, S.; Penionzhkevich, Yu.E.; Balabanski, D.L.; Borremans, D.; Himpe, P.; Neyens, G.; Sawicka, M.

    2004-02-27

    The application of the Time Dependent Perturbed Angular Distribution (TDPAD) method to study isomeric states produced and oriented in projectile-fragmentation reactions provides the opportunity to perform nuclear-moment measurements in a wide range of neutron-rich nuclei, unaccessible by other means. An absolute necessity for the application of the TDPAD technique is a spin-aligned ensemble of nuclei. The preliminary results from a recent application of this method on 61mFe and 54mFe at GANIL, Caen, France showed that a significant increase of the amount of the observed alignment, compared to our previous measurement on 67mNi and 69mCu, can be obtained. Some experimental details, concerning the conservation of the reaction obtained alignment, are discussed.

  19. Non-Contact Measurement of Thermal Diffusivity in Ion-Implanted Nuclear Materials.

    PubMed

    Hofmann, F; Mason, D R; Eliason, J K; Maznev, A A; Nelson, K A; Dudarev, S L

    2015-01-01

    Knowledge of mechanical and physical property evolution due to irradiation damage is essential for the development of future fission and fusion reactors. Ion-irradiation provides an excellent proxy for studying irradiation damage, allowing high damage doses without sample activation. Limited ion-penetration-depth means that only few-micron-thick damaged layers are produced. Substantial effort has been devoted to probing the mechanical properties of these thin implanted layers. Yet, whilst key to reactor design, their thermal transport properties remain largely unexplored due to a lack of suitable measurement techniques. Here we demonstrate non-contact thermal diffusivity measurements in ion-implanted tungsten for nuclear fusion armour. Alloying with transmutation elements and the interaction of retained gas with implantation-induced defects both lead to dramatic reductions in thermal diffusivity. These changes are well captured by our modelling approaches. Our observations have important implications for the design of future fusion power plants. PMID:26527099

  20. Non-Contact Measurement of Thermal Diffusivity in Ion-Implanted Nuclear Materials

    SciTech Connect

    Hofmann, F.; Mason, D. R.; Eliason, J. K.; Maznev, A. A.; Nelson, K. A.; Dudarev, S. L.

    2015-11-03

    Knowledge of mechanical and physical property evolution due to irradiation damage is essential for the development of future fission and fusion reactors. Ion-irradiation provides an excellent proxy for studying irradiation damage, allowing high damage doses without sample activation. Limited ion-penetration-depth means that only few-micron-thick damaged layers are produced. Substantial effort has been devoted to probing the mechanical properties of these thin implanted layers. Yet, whilst key to reactor design, their thermal transport properties remain largely unexplored due to a lack of suitable measurement techniques. Here we demonstrate non-contact thermal diffusivity measurements in ion-implanted tungsten for nuclear fusion armour. Alloying with transmutation elements and the interaction of retained gas with implantation-induced defects both lead to dramatic reductions in thermal diffusivity. These changes are well captured by our modelling approaches. Our observations have important implications for the design of future fusion power plants.

  1. Advanced Nuclear Measurements - Sensitivity Analysis Emerging Safeguards, Problems and Proliferation Risk

    SciTech Connect

    Dreicer, J.S.

    1999-07-15

    During the past year this component of the Advanced Nuclear Measurements LDRD-DR has focused on emerging safeguards problems and proliferation risk by investigating problems in two domains. The first is related to the analysis, quantification, and characterization of existing inventories of fissile materials, in particular, the minor actinides (MA) formed in the commercial fuel cycle. Understanding material forms and quantities helps identify and define future measurement problems, instrument requirements, and assists in prioritizing safeguards technology development. The second problem (dissertation research) has focused on the development of a theoretical foundation for sensor array anomaly detection. Remote and unattended monitoring or verification of safeguards activities is becoming a necessity due to domestic and international budgetary constraints. However, the ability to assess the trustworthiness of a sensor array has not been investigated. This research is developing an anomaly detection methodology to assess the sensor array.

  2. Non-Contact Measurement of Thermal Diffusivity in Ion-Implanted Nuclear Materials

    DOE PAGESBeta

    Hofmann, F.; Mason, D. R.; Eliason, J. K.; Maznev, A. A.; Nelson, K. A.; Dudarev, S. L.

    2015-11-03

    Knowledge of mechanical and physical property evolution due to irradiation damage is essential for the development of future fission and fusion reactors. Ion-irradiation provides an excellent proxy for studying irradiation damage, allowing high damage doses without sample activation. Limited ion-penetration-depth means that only few-micron-thick damaged layers are produced. Substantial effort has been devoted to probing the mechanical properties of these thin implanted layers. Yet, whilst key to reactor design, their thermal transport properties remain largely unexplored due to a lack of suitable measurement techniques. Here we demonstrate non-contact thermal diffusivity measurements in ion-implanted tungsten for nuclear fusion armour. Alloying withmore » transmutation elements and the interaction of retained gas with implantation-induced defects both lead to dramatic reductions in thermal diffusivity. These changes are well captured by our modelling approaches. Our observations have important implications for the design of future fusion power plants.« less

  3. Use of First Order Reversal Curve Measurements to Understand Barkhausen Noise Emission in Nuclear Steel

    SciTech Connect

    McCloy, John S.; Ramuhalli, Pradeep; Henager, Charles H.

    2013-02-25

    A prototypical ferritic/martensitic alloy, HT-9, of interest to the nuclear materials community was investigated for microstructure effects on Barkhausen noise emission and first-order reversal curve (FORC) analysis for three different heat-treated samples. It was observed that Barkhausen noise emission and reversible component of magnetization, computed from the FORC data, decreased with increasing measured mechanical hardness. The results are discussed in terms of the use of magnetic signatures for use in nondestructive interrogation of radiation damage and other microstructural changes in ferritic/martensitic alloys. FORC analysis is shown to be particularly useful for detailed characterization of defect density and pinning, which can be correlated to bulk non-destructive evaluation field measurements such as Barkhausen noise emission.

  4. Non-Contact Measurement of Thermal Diffusivity in Ion-Implanted Nuclear Materials

    PubMed Central

    Hofmann, F.; Mason, D. R.; Eliason, J. K.; Maznev, A. A.; Nelson, K. A.; Dudarev, S. L.

    2015-01-01

    Knowledge of mechanical and physical property evolution due to irradiation damage is essential for the development of future fission and fusion reactors. Ion-irradiation provides an excellent proxy for studying irradiation damage, allowing high damage doses without sample activation. Limited ion-penetration-depth means that only few-micron-thick damaged layers are produced. Substantial effort has been devoted to probing the mechanical properties of these thin implanted layers. Yet, whilst key to reactor design, their thermal transport properties remain largely unexplored due to a lack of suitable measurement techniques. Here we demonstrate non-contact thermal diffusivity measurements in ion-implanted tungsten for nuclear fusion armour. Alloying with transmutation elements and the interaction of retained gas with implantation-induced defects both lead to dramatic reductions in thermal diffusivity. These changes are well captured by our modelling approaches. Our observations have important implications for the design of future fusion power plants. PMID:26527099

  5. Experimental Concept for a Precision Measurement of Nuclear Recoil Ionization Yields for Low Mass WIMP Searches

    NASA Astrophysics Data System (ADS)

    Saab, T.; Figueroa-Feliciano, E.

    2016-07-01

    Understanding the response of dark matter detectors at the lowest recoil energies is important for correctly interpreting data from current experiments or predicting the sensitivity of future experiments to low mass weakly interacting massive particles. In particular, the ionization yield is essential for determining the correct recoil energy of candidate nuclear recoil events; however, few measurements in cryogenic crystals exist below 1 keV. Using the voltage-assisted calorimetric ionization detection technique with a mono-energetic neutron source, we show that it is possible to determine the ionization yield in cryogenic crystals down to an energy to 100 eV. This measurement will also determine the statistics of ionization production at these low energies.

  6. Current activities and future plans for nuclear data measurements at J-PARC

    NASA Astrophysics Data System (ADS)

    Kimura, Atsushi; Harada, Hideo; Nakamura, Shoji; Iwamoto, Osamu; Toh, Yosuke; Koizumi, Mitsuo; Kitatani, Fumito; Furutaka, Kazuyoshi; Igashira, Masayuki; Katabuchi, Tatsuya; Mizumoto, Motoharu; Hori, Jun-ichi; Kino, Koichi; Kiyanagi, Yoshiaki

    2015-12-01

    In order to improve the data accuracy of neutron-capture cross-sections of minor actinides (MAs) and long-lived fission products (LLFPs), a new experimental instrument named "Accurate Neutron-Nucleus Reaction measurement Instrument" (ANNRI) has been constructed in the Materials and Life science experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC), and measurements of neutron-capture cross-sections of MAs, LLFPs and some stable isotopes with high-intensity pulsed neutrons have been started. The analyses for 244Cm, 246Cm, 241Am and 237Np were finished; those for 129I, 107Pd, 99Tc , 93Zr and some stable isotopes are in progress. These results will give significant contributions in the field of developing innovative nuclear systems.

  7. Non-Contact Measurement of Thermal Diffusivity in Ion-Implanted Nuclear Materials

    NASA Astrophysics Data System (ADS)

    Hofmann, F.; Mason, D. R.; Eliason, J. K.; Maznev, A. A.; Nelson, K. A.; Dudarev, S. L.

    2015-11-01

    Knowledge of mechanical and physical property evolution due to irradiation damage is essential for the development of future fission and fusion reactors. Ion-irradiation provides an excellent proxy for studying irradiation damage, allowing high damage doses without sample activation. Limited ion-penetration-depth means that only few-micron-thick damaged layers are produced. Substantial effort has been devoted to probing the mechanical properties of these thin implanted layers. Yet, whilst key to reactor design, their thermal transport properties remain largely unexplored due to a lack of suitable measurement techniques. Here we demonstrate non-contact thermal diffusivity measurements in ion-implanted tungsten for nuclear fusion armour. Alloying with transmutation elements and the interaction of retained gas with implantation-induced defects both lead to dramatic reductions in thermal diffusivity. These changes are well captured by our modelling approaches. Our observations have important implications for the design of future fusion power plants.

  8. A program to measure new energetic particle nuclear interaction cross sections

    NASA Technical Reports Server (NTRS)

    Guzik, T. G.; Albergo, S.; Chen, C. X.; Costa, S.; Crawford, H. J.; Engelage, J.; Ferrando, P.; Flores, I.; Greiner, L.; Jones, F. C.

    1994-01-01

    The Transport Collaboration, consisting of researchers from institutions in France, Germany, Italy, and the USA, has established a program to make new measurements of nuclear interaction cross sections for heavy projectiles (Z greater than or equal to 2) in targets of liquid H2, He and heavier materials. Such cross sections directly affect calculations of galactic and solar cosmic ray transport through matter and are needed for accurate radiation hazard assessment. To date, the collaboration has obtained data using the Lawrence Berkeley Laboratory Bevalac HISS facility with 20 projectiles from He-4 to Ni-58 in the energy range 393-910 MeV/nucleon. Preliminary results from the analysis of these data are presented here and compared to other measurements and to cross section prediction formulae.

  9. The patient as a radioactive source: an intercomparison of survey meters for measurements in nuclear medicine.

    PubMed

    Uhrhan, K; Drzezga, A; Sudbrock, F

    2014-11-01

    In this work, the radiation exposure in nuclear medicine is evaluated by measuring dose rates in the proximity of patients and those in close contact to sources like capsules and syringes. A huge number of different survey meters (SMs) are offered commercially. This topic has recently gained interest since dosemeters and active personal dosemeters (APD) for the new dose quantities (ambient and directional dose equivalent) have become available. One main concern is the practical use of SMs and APD in daily clinical routines. Therefore, the radiation field of four common radiopharmaceuticals containing (18)F, (90)Y, (99m)Tc and (131)I in radioactive sources or after application to the patient was determined. Measurements were carried out with different SMs and for several distances. Dose rates decline significantly with the distance to the patient, and with some restrictions, APD can be used as SMs. PMID:25071244

  10. Quantitative PCR-Based Measurement of Nuclear and Mitochondrial DNA Damage and Repair in Mammalian Cells

    PubMed Central

    Furda, Amy; Santos, Janine H.; Meyer, Joel N.; Van Houten, Bennett

    2015-01-01

    In this chapter, we describe a gene-specific quantitative PCR (QPCR)-based assay for the measurement of DNA damage, using amplification of long DNA targets. This assay has been used extensively to measure the integrity of both nuclear and mitochondrial genomes exposed to different genotoxins and has proven to be particularly valuable in identifying reactive oxygen species-mediated mitochondrial DNA damage. QPCR can be used to quantify both the formation of DNA damage as well as the kinetics of damage removal. One of the main strengths of the assay is that it permits monitoring the integrity of mtDNA directly from total cellular DNA without the need for isolating mitochondria or a separate step of mitochondrial DNA purification. Here we discuss advantages and limitations of using QPCR to assay DNA damage in mammalian cells. In addition, we give a detailed protocol of the QPCR assay that helps facilitate its successful deployment in any molecular biology laboratory. PMID:24623245

  11. An investigation of temperature measurement methods in nuclear power plant reactor pressure vessel annealing

    SciTech Connect

    Acton, R.U.; Gill, W.; Sais, D.J.; Schulze, D.H.; Nakos, J.T.

    1996-05-01

    The objective of this project was to provide an assessment of several methods by which the temperature of a commercial nuclear power plant reactor pressure vessel (RPV) could be measured during an annealing process. This project was a coordinated effort between DOE`s Office of Nuclear Energy, Science and Technology; DOE`s Light Water Reactor Technology Center at Sandia National Laboratories; and the Electric Power Research Institute`s Non- Destructive Evaluation Center. Ball- thermocouple probes similar to those described in NUREG/CR-5760, spring-loaded, metal- sheathed thermocouple probes, and 1778 air- suspended thermocouples were investigated in experiments that heated a section of an RPV wall to simulate a thermal annealing treatment. A parametric study of ball material, emissivity, thermal conductivity, and thermocouple function locations was conducted. Also investigated was a sheathed thermocouple failure mode known as shunting (electrical breakdown of insulation separating the thermocouple wires). Large errors were found between the temperature as measured by the probes and the true RPV wall temperature during heat-up and cool-down. At the annealing soak temperature, in this case 454{degrees}C [850`F], all sensors measured the same temperature within about {plus_minus}5% (23.6{degrees}C [42.5{degrees}F]). Because of these errors, actual RPV wall heating and cooling rates differed from those prescribed (by up to 29%). Shunting does not appear to be a problem under these conditions. The large temperature measurement errors led to the development of a thermal model that predicts the RPV wall temperature from the temperature of a ball- probe. Comparisons between the model and the experimental data for ball-probes indicate that the model could be a useful tool in predicting the actual RPV temperature based on the indicated ball- probe temperature. The model does not predict the temperature as well for the spring-loaded and air suspended probes.

  12. Rapid measurements of heterogeneity in sandstones using low-field nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Mitchell, Jonathan

    2014-03-01

    Sandstone rocks can contain microscopic variations in composition that complicate interpretation of nuclear magnetic resonance (NMR) relaxation time measurements. In this work, methods for assessing the degree of sample heterogeneity are demonstrated in three sandstones. A two-dimensional T1-Δχapp correlation (where Δχapp is the apparent solid/liquid magnetic susceptibility contrast) reveals the microscopic heterogeneity in composition, whilst a spatially resolved T1 profile reveals the macroscopic structural heterogeneity. To perform these measurements efficiently, a rapid measure of longitudinal T1 relaxation time has been implemented on a low-field NMR spectrometer with a magnetic field strength B0=0.3 T. The “double-shot” T1 pulse sequence is appropriate for analysis of porous materials in general. Example relaxation time distributions are presented for doped water phantoms to validate the method. The acquisition time of the double-shot T1 sequence is equivalent to the single-shot Carr-Purcell Meiboom-Gill (CPMG) sequence used routinely in petrophysics to measure transverse T2 relaxation. Rapid T1 measurements enable practical studies of core plugs at magnetic field strengths previously considered inappropriate, as T1 is independent of molecular diffusion through pore-scale (internal) magnetic field gradients.

  13. The Effect of Measurement Bias on Nuclear Criticality Safety Calculations for WIPP TRUPACT-II Shipments

    SciTech Connect

    Blackwood, Larry G.; Harker, Yale D.

    2000-12-15

    Current nuclear criticality safety limit requirements for transporting TRUPACT-II waste containers to the U.S. Department of Energy's Waste Isolation Pilot Plant (WIPP) specify that the {sup 239}Pu fissile gram equivalent (FGE) plus two times its measurement error must be {<=}325 g for a payload of fourteen 55-gal drums. The authorized method for calculating a TRUPACT-II FGE measurement error value is to take the square root of the sum of the squared error values for the individual containers (often called root-sum-squares or simply RSS). However, to the extent that the individual drum measurements contain common bias effects (e.g., due to common calibration or other adjustment factors), the corresponding measurement errors are correlated, and simple RSS calculations will underestimate the true error in the TRUPACT-II FGE value.The RSS calculations assume independence, while common bias effects can induce strong correlations between the errors in measurements. Significant bias effects can occur when the matrix characteristics for a particular waste type are not fully accounted for in the measurement process. Depending on the relative size of the bias error compared to precision error, the true measurement error can be greater than twice that calculated by RSS. In such cases, the FGE shipping requirement may not be met. To avoid underestimating the error, bias components should be estimated and propagated separately (combined only at the final step in the TRUPACT-II FGE calculation), or the effect of bias on covariance between measurements must be calculated. These covariance terms then need to be included in the final uncertainty calculations.

  14. Environmental radioactivity measurements in Greece following the Fukushima Daichi nuclear accident.

    PubMed

    Potiriadis, C; Kolovou, M; Clouvas, A; Xanthos, S

    2012-07-01

    Since the double disaster of the 9.0 magnitude earthquake and tsunami that affected hundreds of thousands of people and seriously damaged the Fukushima Daichi power plant in Japan on 11 March 2011, traces of radioactive emissions from Fukushima have spread across the entire northern hemisphere. The radioactive isotope of iodine (131)I that was generated by the nuclear accident in Fukushima arrived in Greece on 24 March 2011. Radioactive iodine is present in the air either as gas or bound to particles (aerosols). The maximum (131)I concentrations were measured between 3 and 5 April 2011. In aerosols the maximum (131)I values measured in Southern Greece (Athens) and Northern Greece (Thessaloniki) were 585±70 and 408±61 μΒq m(-3), respectively. (131)I concentrations in gas were about 3.5 times higher than in aerosols. Since 29 April 2011, the (131)I concentration has been below detection limits. Traces of (137)Cs and (134)Cs were also measured in the air filters with an activity ratio of (137)Cs/(134)Cs equal to 1 and (131)I/(137)Cs activity ratio of about 3. Since 16 May 2011, the (137)Cs concentration in air has been determined to be about the same as before the Fukushima accident. Traces of (131)I were also measured in grass and milk. The maximum measured activity of (131)I in sheep milk was about 2 Bq l(-1) which is 5000 times less than that measured in Greece immediately after the Chernobyl accident. The measured activity concentrations of artificial radionuclides in Greece due to the Fukushima release, have been very low, with no impact on human health. PMID:22090415

  15. Nuclear space-valued stochastic differential equations driven by Poisson random measures

    SciTech Connect

    Xiong, J.

    1992-01-01

    The thesis is devoted primarily to the study of stochastic differential equations on duals of nuclear spaces driven by Poisson random measures. The existence of a weak solution is obtained by the Galerkin method and the uniqueness is established by implementing the Yamada-Watanabe argument in the present setup. When the magnitudes of the driving terms are small enough and the Poisson streams occur frequently enough, it is proved that the stochastic differential equations mentioned above can be approximated by diffusion equations. Finally, the author considers a system of interacting stochastic differential equations driven by Poisson random measures. Let (X[sup n][sub i](t), [center dot][center dot][center dot], X[sup n][sub n](t)) be the solution of this system and consider the empirical measures [zeta]n([omega],B) [identical to] (1/n) (sum of j=1 to n) [delta]x[sup n][sub j]([center dot],[omega])(B) (n[>=]1). It is provided that [zeta][sub n] converges in distribution to a non-random measure which is the unique solution of a McKean-Vlasov equation. The above problems are motivated by applications to neurophysiology, in particular, to the fluctuation of voltage potentials of spatially distributed neurons and to the study of asymptotic behavior of large systems of interacting neurons.

  16. Nuclear relaxation measurements in organic semiconducting polymers for application to organic spintronics

    NASA Astrophysics Data System (ADS)

    Thenell, E. F.; Limes, M. E.; Sorte, E. G.; Vardeny, Z. V.; Saam, B.

    2015-01-01

    NMR measurements of spin-lattice relaxation of hydrogen nuclei in two prototype organic semiconducting solids, MEH-PPV and DOO-PPV, were carried out for temperatures between 4.2 K and room temperature, and for applied magnetic fields between 1.25 and 4.7 T. These π -conjugated polymers are of interest for use as the active semiconducting layer in spintronic devices. They typically exhibit weak spin-orbit coupling, and the interaction with inhomogeneous hyperfine fields generated by the nuclear spins plays a significant, if not dominant, role in the spin coherence and spin relaxation of electronic charge carriers. Our studies were conducted on unbiased bulk material with no photo-illumination. The characteristic 1H longitudinal relaxation times in these materials ranges from hundreds of milliseconds to >1000 s, and are predominantly nonmonoexponential. We present the data both in terms of a recovery time, T1 /2, corresponding to 50% recovery of thermal magnetization from saturation and in terms of a "T1 spectrum" produced via a numerical Laplace transform of the time-domain data. The evidence best supports relaxation to paramagnetic centers (radicals) mediated by nuclear spin diffusion as the primary mechanism: the observed relaxation is predominantly nonmonoexponential, and a characteristic T1 minimum as a function of temperature is apparent for both materials somewhere between 77 K and room temperature. The paramagnetic centers may be somewhat-delocalized charge-carrier pairs (i.e., polarons) along the polymer backbone, although the concentration in an unbiased sample (no carrier injection) should be very low. Alternatively, the centers may be localized defects, vacancies, or impurities. Our results may also be used to judge the feasibility of Overhauser-type dynamic nuclear polarization from polarized charge carriers or optically pumped exciton states.

  17. Nuclear Structure Measurements of Fermium-254 and Advances in Target Production Methodologies

    NASA Astrophysics Data System (ADS)

    Gothe, Oliver Ralf

    The Berkeley Gas-filled Separator (BGS) has been upgraded with a new gas control system. It allows for accurate control of hydrogen and helium gas mixtures. This greatly increases the capabilities of the separator by reducing background signals in the focal plane detector for asymmetric nuclear reactions. It has also been shown that gas mixtures can be used to focus the desired reaction products into a smaller area, thereby increasing the experimental efficiency. A new electrodeposition cell has been developed to produce metal oxide targets for experiments at the BGS. The new cell has been characterized and was used to produce americium targets for the production of element 115 in the reaction 243Am(48Ca.3n) 288115. Additionally, a new method of producing targets for nuclear reactions was explored. A procedure for producing targets via Polymer Assisted Deposition (PAD) was developed and targets produced via this method were tested using the nuclear reaction 208Pb(40Ar.4 n)244Fm to determine their in-beam performance. It was determined that the silicon nitride backings used in this procedure are not feasible due to their crystal structures, and alternative backing materials have been tested and proposed. A previously unknown level in 254Fm has been identified at 985.7 keV utilizing a newly developed low background coincident apparatus. 254m was produced in the reaction 208Pb(48Ca. n)254No. Reaction products were guided to the two-clover low background detector setup via a recoil transfer chamber. The new level has been assigned a spin of 2- and has tentatively been identified as the octupole vibration in 254Fm. Transporting evaporation residues to a two-clover, low background detector setup can effectively be used to perform gamma-spectroscopy measurements of nuclei that are not accessible by current common methodologies. This technique provides an excellent addition to previously available tools such as in-beam spectroscopy and gamma-ray tracking arrays.

  18. Ambient Dose Equivalent measured at the Instituto Nacional de Cancerologia Department of Nuclear Medicine

    SciTech Connect

    Avila, O.; Torres-Ulloa, C. L.; Medina, L. A.; Trujillo-Zamudio, F. E.; Gamboa de Buen, I.; Buenfil, A. E.; Brandan, M. E.

    2010-12-07

    Ambient dose equivalent values were determined in several sites at the Instituto Nacional de Cancerologia, Departmento de Medicina Nuclear, using TLD-100 and TLD-900 thermoluminescent dosemeters. Additionally, ambient dose equivalent was measured at a corridor outside the hospitalization room for patients treated with {sup 137}Cs brachytherapy. Dosemeter calibration was performed at the Instituto Nacional de Investigaciones Nucleares, Laboratorio de Metrologia, to known {sup 137}Cs gamma radiation air kerma. Radionuclides considered for this study are {sup 131}I, {sup 18}F, {sup 67}Ga, {sup 99m}Tc, {sup 111}In, {sup 201}Tl and {sup 137}Cs, with main gamma energies between 93 and 662 keV. Dosemeters were placed during a five month period in the nuclear medicine rooms (containing gamma-cameras), injection corridor, patient waiting areas, PET/CT study room, hot lab, waste storage room and corridors next to the hospitalization rooms for patients treated with {sup 131}I and {sup 137}Cs. High dose values were found at the waste storage room, outside corridor of {sup 137}Cs brachytherapy patients and PET/CT area. Ambient dose equivalent rate obtained for the {sup 137}Cs brachytherapy corridor is equal to (18.51{+-}0.02)x10{sup -3} mSv/h. Sites with minimum doses are the gamma camera rooms, having ambient dose equivalent rates equal to (0.05{+-}0.03)x10{sup -3} mSv/h. Recommendations have been given to the Department authorities so that further actions are taken to reduce doses at high dose sites in order to comply with the ALARA principle (as low as reasonably achievable).

  19. Parametric study of the energy deposition inside the calorimeter measuring the nuclear heating in Material Testing Reactors

    NASA Astrophysics Data System (ADS)

    Amharrak, H.; Reynard-Carette, C.; Lyoussi, A.; Carette, M.; Brun, J.; De Vita, C.; Fourmentel, D.; Villard, J.-F.

    2015-11-01

    The nuclear heating measurements in Material Testing Reactors (MTRs) are crucial for the study of nuclear materials and fuels under irradiation. The reference measurements of this nuclear heating are especially performed by a differential calorimeter including a graphite sample material and two calorimetric cells. Then these measurements are used for other experimental conditions in order to predict the nuclear heating and thermal conditions induced in the irradiation devices. This paper will present simulations with MCNP5 Monte-Carlo transport code (using ENDF/B-VI nuclear data library) to evaluate the nuclear heating inside the calorimeter during irradiation campaigns of the CARMEN-1P mock-up inside OSIRIS reactor periphery (MTR based on Saclay, France). The whole complete geometry of the sensor has been considered. The calculation method corresponds to a calculation in two steps. Consequently, we used as an input source in the model, the neutron and photon spectra calculated in various experimental locations tested during the irradiation campaign (H9, H10, H11, D9). After a description of the differential calorimeter sensor, the MCNP5 model used for the calculations of nuclear heating inside the calorimeter elements is introduced by two quantities: KERMA and energy deposition rate per mass unit. The Charged Particle Equilibrium (CPE) inside the calorimeter elements is studied. The contribution of prompt gamma and neutron is determined. A comparison between this total nuclear heating calculation and the experimental results in a graphite sample will be made. Then parametric studies performed on the influence of the various calorimeter components on the nuclear heating are presented and discussed. The studies of the influence of the nature of materials, the sensor jacket, the source type and the comparison of the results obtained for the two calorimetric cells leads to some proposals for the sensor improvement.

  20. Nuclear Magnetic Dipole and Electric Quadrupole Moments: Their Measurement and Tabulation as Accessible Data

    SciTech Connect

    Stone, N. J.

    2015-09-15

    The most recent tabulations of nuclear magnetic dipole and electric quadrupole moments have been prepared and published by the Nuclear Data Section of the IAEA, Vienna [N. J. Stone, Report No. INDC(NDS)-0650 (2013); Report No. INDC(NDS)-0658 (2014)]. The first of these is a table of recommended quadrupole moments for all isotopes in which all experimental results are made consistent with a limited number of adopted standards for each element; the second is a combined listing of all measurements of both moments. Both tables cover all isotopes and energy levels. In this paper, the considerations relevant to the preparation of both tables are described, together with observations as to the importance and (where appropriate) application of necessary corrections to achieve the “best” values. Some discussion of experimental methods is included with emphasis on their precision. The aim of the published quadrupole moment table is to provide a standard reference in which the value given for each moment is the best available and for which full provenance is given. A table of recommended magnetic dipole moments is in preparation, with the same objective in view.

  1. Development of neutron measurement in high gamma field using new nuclear emulsion

    SciTech Connect

    Kawarabayashi, J.; Ishihara, K.; Takagi, K.; Tomita, H.; Iguchi, T.; Naka, T.; Morishima, K.; Maeda, S.

    2011-07-01

    To precisely measure the neutron emissions from a spent fuel assembly of a fast breeder reactor, we formed nuclear emulsions based on a non-sensitized Oscillation Project with Emulsion tracking Apparatus (OPERA) film with AgBr grain sizes of 60, 90, and 160 nm. The efficiency for {sup 252}Cf neutron detection of the new emulsion was calculated to be 0.7 x 10{sup -4}, which corresponded to an energy range from 0.3 to 2 MeV and was consistent with a preliminary estimate based on experimental results. The sensitivity of the new emulsion was also experimentally estimated by irradiating with 565 keV and 14 MeV neutrons. The emulsion with an AgBr grain size of 60 nm had the lowest sensitivity among the above three emulsions but was still sensitive enough to detect protons. Furthermore, the experimental data suggested that there was a threshold linear energy transfer of 15 keV/{mu}m for the new emulsion, below which no silver clusters developed. Further development of nuclear emulsion with an AgBr grain size of a few tens of nanometers will be the next stage of the present study. (authors)

  2. Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR.

    PubMed

    Balzan, Riccardo; Fernandes, Laetitia; Comment, Arnaud; Pidial, Laetitia; Tavitian, Bertrand; Vasos, Paul R

    2016-01-01

    The main limitation of NMR-based investigations is low sensitivity. This prompts for long acquisition times, thus preventing real-time NMR measurements of metabolic transformations. Hyperpolarization via dissolution DNP circumvents part of the sensitivity issues thanks to the large out-of-equilibrium nuclear magnetization stemming from the electron-to-nucleus spin polarization transfer. The high NMR signal obtained can be used to monitor chemical reactions in real time. The downside of hyperpolarized NMR resides in the limited time window available for signal acquisition, which is usually on the order of the nuclear spin longitudinal relaxation time constant, T1, or, in favorable cases, on the order of the relaxation time constant associated with the singlet-state of coupled nuclei, TLLS. Cellular uptake of endogenous molecules and metabolic rates can provide essential information on tumor development and drug response. Numerous previous hyperpolarized NMR studies have demonstrated the relevancy of pyruvate as a metabolic substrate for monitoring enzymatic activity in vivo. This work provides a detailed description of the experimental setup and methods required for the study of enzymatic reactions, in particular the pyruvate-to-lactate conversion rate in presence of lactate dehydrogenase (LDH), by hyperpolarized NMR. PMID:26967906

  3. Traceability for measurements of radioactivity in waste materials arising from nuclear site decommissioning

    NASA Astrophysics Data System (ADS)

    Dean, Julian C. J.; Adsley, Ian; Burgess, Peter H.

    2007-08-01

    Site decommissioning is now a major aspect of the work of the nuclear industry worldwide. One of its many technical challenges is the need to measure levels of radioactivity in a range of materials (e.g. concrete, brick and steel) in order that radioactive waste may be identified, sentenced and consigned to the appropriate waste stream in accordance with national regulations. This is done using any of a number of measurement techniques, falling under three categories: (i) bulk monitoring (for γ and neutron emitters), (ii) surface monitoring (predominantly for α and β emitters) and (iii) radiochemical analysis. The last is often used to determine a 'radionuclide fingerprint' for a particular operational area for use in conjunction with data from in situ monitoring. Traceability to national standards can be difficult to demonstrate for measurements of this type. Only a limited number of standards and reference materials are available, and their chemical and physical forms do not match those of the very wide range of samples being measured. Traceability for surface measurements is further complicated by the subjective nature of monitoring using hand-held detectors. This paper describes some of the detector types used for γ non-destructive assay (NDA) and for surface measurements, gives examples of currently available standards and calibration procedures and provides some guidance in how to achieve traceability. A generic analysis regime for an operational area is presented which demonstrates points where traceability can, in principle, be attained. A new methodology for developing 'realistic' large-volume standard sources, traceable to national standards, has been developed by the National Physical Laboratory (NPL), and this is described.

  4. CONDENSED MATTER: STRUCTURE, MECHANICAL AND THERMAL PROPERTIES: Theoretical Investigations on the Off-Center Displacement of Co2+ in SrO by Analyzing Its Anisotropic g Factors

    NASA Astrophysics Data System (ADS)

    Lu, Guang-Duo; Zhang, Huai-Wu; Tang, Xiao-Li; Zhong, Zhi-Yong; Peng, Long

    2009-08-01

    The off-center displacement of Co2+ ion in SrO crystal is investigated by analyzing its anisotropic g factors gx, gy and gz through diagonalization of the 6 × 6 energy matrix within 4T1 ground state for a 3d7 ion under rhombic symmetry. In the matrix, the contributions from the admixtures of various J( = 1/2, 3/2, 5/2) states and the fourth-order term Dη of rhombic crystal-fields and the ligand orbitals and spin-orbit coupling interactions, which are usually ignored in the previous studies, are considered. Both g factors (gx = 4.172, gy = 5.004 and gz = 2.133) and the off-displacement value (ΔR approx 0.023 nm) show good agreement with the experimental data.

  5. Filter Measurement System for Nuclear Material Storage Canisters. End of Year Report FY 2013

    SciTech Connect

    Moore, Murray E.; Reeves, Kirk P.

    2014-02-03

    A test system has been developed at Los Alamos National Laboratory to measure the aerosol collection efficiency of filters in the lids of storage canisters for special nuclear materials. Two FTS (filter test system) devices have been constructed; one will be used in the LANL TA-55 facility with lids from canisters that have stored nuclear material. The other FTS device will be used in TA-3 at the Radiation Protection Division’s Aerosol Engineering Facility. The TA-3 system will have an expanded analytical capability, compared to the TA-55 system that will be used for operational performance testing. The LANL FTS is intended to be automatic in operation, with independent instrument checks for each system component. The FTS has been described in a complete P&ID (piping and instrumentation diagram) sketch, included in this report. The TA-3 FTS system is currently in a proof-of-concept status, and TA-55 FTS is a production-quality prototype. The LANL specification for (Hagan and SAVY) storage canisters requires the filter shall “capture greater than 99.97% of 0.45-micron mean diameter dioctyl phthalate (DOP) aerosol at the rated flow with a DOP concentration of 65±15 micrograms per liter”. The percent penetration (PEN%) and pressure drop (DP) of fifteen (15) Hagan canister lids were measured by NFT Inc. (Golden, CO) over a period of time, starting in the year 2002. The Los Alamos FTS measured these quantities on June 21, 2013 and on Oct. 30, 2013. The LANL(6-21-2013) results did not statistically match the NFT Inc. data, and the LANL FTS system was re-evaluated, and the aerosol generator was replaced and the air flow measurement method was corrected. The subsequent LANL(10-30-2013) tests indicate that the PEN% results are statistically identical to the NFT Inc. results. The LANL(10-30-2013) pressure drop measurements are closer to the NFT Inc. data, but future work will be investigated. An operating procedure for the FTS (filter test system) was written, and

  6. Nuclear magnetic resonance measurements of velocity distributions in an ultrasonically vibrated granular bed.

    PubMed

    Huntley, J M; Tarvaz, T; Mantle, M D; Sederman, A J; Gladden, L F; Sheikh, N A; Wildman, R D

    2014-05-13

    We report the results of nuclear magnetic resonance imaging experiments on granular beds of mustard grains fluidized by vertical vibration at ultrasonic frequencies. The variation of both granular temperature and packing fraction with height was measured within the three-dimensional cell for a range of vibration frequencies, amplitudes and numbers of grains. Small increases in vibration frequency were found--contrary to the predictions of classical 'hard-sphere' expressions for the energy flux through a vibrating boundary--to result in dramatic reductions in granular temperature. Numerical simulations of the grain-wall interactions, using experimentally determined Hertzian contact stiffness coefficients, showed that energy flux drops significantly as the vibration period approaches the grain-wall contact time. The experiments thus demonstrate the need for new models for 'soft-sphere' boundary conditions at ultrasonic frequencies. PMID:24711488

  7. Nuclear magnetic resonance measurements of velocity distributions in an ultrasonically vibrated granular bed

    PubMed Central

    Huntley, J. M.; Tarvaz, T.; Mantle, M. D.; Sederman, A. J.; Gladden, L. F.; Sheikh, N. A.; Wildman, R. D.

    2014-01-01

    We report the results of nuclear magnetic resonance imaging experiments on granular beds of mustard grains fluidized by vertical vibration at ultrasonic frequencies. The variation of both granular temperature and packing fraction with height was measured within the three-dimensional cell for a range of vibration frequencies, amplitudes and numbers of grains. Small increases in vibration frequency were found—contrary to the predictions of classical ‘hard-sphere’ expressions for the energy flux through a vibrating boundary—to result in dramatic reductions in granular temperature. Numerical simulations of the grain–wall interactions, using experimentally determined Hertzian contact stiffness coefficients, showed that energy flux drops significantly as the vibration period approaches the grain–wall contact time. The experiments thus demonstrate the need for new models for ‘soft-sphere’ boundary conditions at ultrasonic frequencies. PMID:24711488

  8. Characterization of high-level nuclear waste glass using magnetic measurements

    SciTech Connect

    Senftle, F.E.; Thorpe, A.N.; Grant, J.R.; Barkatt, A.

    1994-12-31

    Magnetic measurements constitute a promising method for the characterization of nuclear waste glasses in view of their simplicity and small sample weight requirements. Initial studies of simulated high-level waste glasses show that the Curie constant is generally a useful indicator of the Fe{sup 2+}:Fe{sup 3+} ratio. Glasses produced by air-cooling in large vessels show systematic deviations between experimental and calcined values, which are indicative of the presence of small amounts of crystalline iron-containing phases. Most of the iron in these phases becomes dissolved in the glass upon re-heating and more rapid quenching. The studies further show that upon leaching the glass in water some of the iron in the surface regions of the glass is converted to a form which has high temperature-independent magnetic susceptibility.

  9. Alternative approach to the standardization of NMR spectra. Direct measurement of nuclear magnetic shielding in molecules.

    PubMed

    Jackowski, Karol; Jaszuński, Michał; Wilczek, Marcin

    2010-02-25

    Exploring the relation between shielding constants, resonance frequencies and magnetic moments of the nuclei we demonstrate that nuclear magnetic shielding can be directly observed from NMR spectra. In this approach, the absolute shielding constants of all the nuclei can be related to a single reference scale, with atomic (3)He as the primary standard. The accuracy of the data obtained using our method is confirmed comparing the (1)H and (13)C shielding constants for a series of deuterated compounds with those determined analyzing the traditional chemical shifts. Since the use of helium-3 is not in general a practical alternative, we next transfer the reference standard to the (2)H signals of external lock solvents, in this way making the method easy and ready for application with most NMR spectrometers. Finally, we illustrate our new method with the measurements of the (2/1)H primary isotope effects in several liquid deuterated solvents. PMID:20112974

  10. EDM measurement in 129Xe atom using dual active feedback nuclear spin maser

    NASA Astrophysics Data System (ADS)

    Sato, T.; Ichikawa, Y.; Ohtomo, Y.; Sakamoto, Y.; Kojima, S.; Funayama, C.; Suzuki, T.; Chikamori, M.; Hikota, E.; Tsuchiya, M.; Furukawa, T.; Yoshimi, A.; Bidinosti, C. P.; Ino, T.; Ueno, H.; Matsuo, Y.; Fukuyama, T.; Asahi, K.

    2015-04-01

    The technique of an active nuclear spin maser is adopted in the search for electric dipole moment in a diamagnetic atom 129Xe. In order to reduce systematic uncertainties arising from long-term drifts of the external magnetic field and from the contact interaction between longitudinal polarized Rb atoms and 129Xe spin, a 3He comagnetometer with a double-cell geometry was employed. The remaining shift, which turned out to show some correlation with the cell temperature, was mitigated by stabilizing the cell temperature. As a result, the frequency drift of the 129Xe maser was reduced from 12 mHz to 700 μHz, and the determination precision of frequency of 8.7 nHz was obtained for a 2×104 s measurement time using the double-cell geometry cell.

  11. Nuclear reaction measurements on tissue-equivalent materials and GEANT4 Monte Carlo simulations for hadrontherapy

    NASA Astrophysics Data System (ADS)

    De Napoli, M.; Romano, F.; D'Urso, D.; Licciardello, T.; Agodi, C.; Candiano, G.; Cappuzzello, F.; Cirrone, G. A. P.; Cuttone, G.; Musumarra, A.; Pandola, L.; Scuderi, V.

    2014-12-01

    When a carbon beam interacts with human tissues, many secondary fragments are produced into the tumor region and the surrounding healthy tissues. Therefore, in hadrontherapy precise dose calculations require Monte Carlo tools equipped with complex nuclear reaction models. To get realistic predictions, however, simulation codes must be validated against experimental results; the wider the dataset is, the more the models are finely tuned. Since no fragmentation data for tissue-equivalent materials at Fermi energies are available in literature, we measured secondary fragments produced by the interaction of a 55.6 MeV u-1 12C beam with thick muscle and cortical bone targets. Three reaction models used by the Geant4 Monte Carlo code, the Binary Light Ions Cascade, the Quantum Molecular Dynamic and the Liege Intranuclear Cascade, have been benchmarked against the collected data. In this work we present the experimental results and we discuss the predictive power of the above mentioned models.

  12. Measuring the Fr Weak Nuclear Charge by Observing a Linear Stark Shift with Small Atomic Samples

    SciTech Connect

    Bouchiat, Marie-Anne

    2008-03-28

    We study the chirality of ground-state alkali atoms in E and B fields, dressed with a circularly-polarized beam near-detuned (< or approx. )1 GHz) from an E-field-assisted forbidden transition such as 7S-8S in Fr. We predict parity violating energy shifts of their sublevels, linear in E and the weak nuclear charge Q{sub W}. A dressing beam of 10 kW/cm{sup 2} at 506 nm produces a shift of {approx}100 {mu}Hz at E=100 V/cm, B > or approx. 50 mG which should be observable with {approx}10{sup 4} Fr atoms confined in an optical dipole trap. We discuss optimal conditions, parameter reversals, and a calibration procedure to measure Q{sub W}.

  13. Measurements of alpha particle energy using nuclear tracks in solids methodology.

    PubMed

    Espinosa, G; Amero, C; Gammage, R B

    2002-01-01

    In this paper we present a method for the measurement of alpha particle energy using polycarbonate materials as nuclear track detectors (NTDs). This method is based on the interaction of the radiation with the solid-state materials, using the relationship between the energy deposited in the material by the ionising particle and the track developed after an established chemical process. The determination of the geometrical parameters of the formed track, such as major axis, minor axis and overall track length, permit determination of the energy of the alpha particle. The track analysis is performed automatically using a digital image system, and the data are processed in a PC with commercial software. In this experiment 148Gd, 238U, 230Th, 239Pu and 244Cm alpha particle emitters were used. The values for alpha particle energy resolution, the linear response to energy, the confidence in the results and the automatisation of the procedure make this method a promising analysis system. PMID:12382812

  14. First measurement of proton-induced low-momentum dielectron radiation off cold nuclear matter

    NASA Astrophysics Data System (ADS)

    HADES Collaboration; Agakishiev, G.; Balanda, A.; Belver, D.; Belyaev, A.; Berger-Chen, J. C.; Blanco, A.; Böhmer, M.; Boyard, J. L.; Cabanelas, P.; Chernenko, S.; Dybczak, A.; Epple, E.; Fabbietti, L.; Fateev, O.; Finocchiaro, P.; Fonte, P.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garzón, J. A.; Gernhäuser, R.; Göbel, K.; Golubeva, M.; González-Díaz, D.; Guber, F.; Gumberidze, M.; Heinz, T.; Hennino, T.; Holzmann, R.; Ierusalimov, A.; Iori, I.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Karavicheva, T.; Koenig, I.; Koenig, W.; Kolb, B. W.; Kornakov, G.; Kotte, R.; Krása, A.; Krizek, F.; Krücken, R.; Kuc, H.; Kühn, W.; Kugler, A.; Kurepin, A.; Ladygin, V.; Lalik, R.; Lang, S.; Lapidus, K.; Lebedev, A.; Liu, T.; Lopes, L.; Lorenz, M.; Maier, L.; Mangiarotti, A.; Markert, J.; Metag, V.; Michalska, B.; Michel, J.; Mishra, D.; Müntz, C.; Naumann, L.; Pachmayer, Y. C.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Reshetin, A.; Rustamov, A.; Sadovsky, A.; Salabura, P.; Schmah, A.; Schwab, E.; Siebenson, J.; Sobolev, Yu. G.; Spataro, S.; Spruck, B.; Ströbele, H.; Stroth, J.; Sturm, C.; Tarantola, A.; Teilab, K.; Tlusty, P.; Traxler, M.; Trebacz, R.; Tsertos, H.; Vasiliev, T.; Wagner, V.; Weber, M.; Wendisch, C.; Wüstenfeld, J.; Yurevich, S.; Zanevsky, Y.

    2012-09-01

    We present data on dielectron emission in proton induced reactions on a Nb target at 3.5 GeV kinetic beam energy measured with HADES installed at GSI. The data represent the first high statistics measurement of proton-induced dielectron radiation from cold nuclear matter in a kinematic regime, where strong medium effects are expected. Combined with the good mass resolution of 2%, it is the first measurement sensitive to changes of the spectral functions of vector mesons, as predicted by models for hadrons at rest or small relative momenta. Comparing the e+e- invariant mass spectra to elementary p + p data, we observe for e+e- momenta Pee<0.8 GeV/c a strong modification of the shape of the spectrum, which we attribute to an additional ρ-like contribution and a decrease of ω yield. These opposite trends are tentatively interpreted as a strong coupling of the ρ meson to baryonic resonances and an absorption of the ω meson, which are two aspects of in-medium modification of vector mesons.

  15. Systematic and Statistical Errors Associated with Nuclear Decay Constant Measurements Using the Counting Technique

    NASA Astrophysics Data System (ADS)

    Koltick, David; Wang, Haoyu; Liu, Shih-Chieh; Heim, Jordan; Nistor, Jonathan

    2016-03-01

    Typical nuclear decay constants are measured at the accuracy level of 10-2. There are numerous reasons: tests of unconventional theories, dating of materials, and long term inventory evolution which require decay constants accuracy at a level of 10-4 to 10-5. The statistical and systematic errors associated with precision measurements of decays using the counting technique are presented. Precision requires high count rates, which introduces time dependent dead time and pile-up corrections. An approach to overcome these issues is presented by continuous recording of the detector current. Other systematic corrections include, the time dependent dead time due to background radiation, control of target motion and radiation flight path variation due to environmental conditions, and the time dependent effects caused by scattered events are presented. The incorporation of blind experimental techniques can help make measurement independent of past results. A spectrometer design and data analysis is reviewed that can accomplish these goals. The author would like to thank TechSource, Inc. and Advanced Physics Technologies, LLC. for their support in this work.

  16. Monitoring of pipelines in nuclear power plants by measuring laser-based mechanical impedance

    NASA Astrophysics Data System (ADS)

    Lee, Hyeonseok; Sohn, Hoon; Yang, Suyoung; Yang, Jinyeol

    2014-06-01

    Using laser-based mechanical impedance (LMI) measurement, this study proposes a damage detection technique that enables structural health monitoring of pipelines under the high temperature and radioactive environments of nuclear power plants (NPPs). The applications of conventional electromechanical impedance (EMI) based techniques to NPPs have been limited, mainly due to the contact nature of piezoelectric transducers, which cannot survive under the high temperature and high radiation environments of NPPs. The proposed LMI measurement technique aims to tackle the limitations of the EMI techniques by utilizing noncontact laser beams for both ultrasound generation and sensing. An Nd:Yag pulse laser is used for ultrasound generation, and a laser Doppler vibrometer is employed for the measurement of the corresponding ultrasound responses. For the monitoring of pipes covered by insulation layers, this study utilizes optical fibers to guide the laser beams to specific target locations. Then, an outlier analysis is adopted for autonomous damage diagnosis. Validation of the proposed LMI technique is carried out on a carbon steel pipe elbow under varying temperatures. A corrosion defect chemically engraved in the specimen is successfully detected.

  17. Time-of-flight mass measurements for nuclear processes in neutron star crusts

    SciTech Connect

    Estrade, Alfredo; Matos, M.; Schatz, Hendrik; Amthor, A. M.; Bazin, D.; Beard, Mary; Becerril, A.; Brown, Edward; Elliot, T; Gade, A.; Galaviz, D.; George, S.; Gupta, Sanjib; Hix, William Raphael; Lau, Rita; Moeller, Peter; Pereira, J.; Portillo, M.; Rogers, A. M.; Shapira, Dan; Smith, E.; Stolz, A.; Wallace, M.; Wiescher, Michael

    2011-01-01

    The location of electron capture heat sources in the crust of accreting neutron stars depends on the masses of extremely neutron-rich nuclei. We present first results from a new implementation of the time-of-flight technique to measure nuclear masses of rare isotopes at the National Supercon- ducting Cyclotron Laboratory. The masses of 16 neutron-rich nuclei in the Sc Ni element range were determined simultaneously, improving the accuracy compared to previous data in 12 cases. The masses of 61V, 63Cr, 66Mn, and 74Ni were measured for the first time with mass excesses of 30.510(890) MeV, 35.280(650) MeV, 36.900(790) MeV, and 49.210(990) MeV, respectively. With the measurement of the 66Mn mass, the location of the two dominant heat sources in the outer crust of accreting neutron stars, which exhibit so called superbursts, is now experimentally constrained. We find that the location of the 66Fe 66Mn electron capture transition occurs sig- nificantly closer to the surface than previously assumed because our new experimental Q-value is 2.1 MeV smaller than predicted by the FRDM mass model. The results also provide new insights into the structure of neutron-rich nuclei around N = 40.

  18. Feasibility study of measuring the 229Th nuclear isomer transition with 233U-doped crystals

    NASA Astrophysics Data System (ADS)

    Stellmer, Simon; Schreitl, Matthias; Kazakov, Georgy A.; Sterba, Johannes H.; Schumm, Thorsten

    2016-07-01

    We propose a simple approach to measure the energy of the few-eV isomeric state in 229Th. To this end, 233U nuclei are doped into VUV-transparent crystals, where they undergo α decay into 229Th, and, with a probability of 2%, populate the isomeric state. These Thm229 nuclei may decay into the nuclear ground state under emission of the sought-after VUV γ ray, whose wavelength can be determined with a spectrometer. Based on measurements of the optical transmission of 238U:CaF2 crystals in the VUV range, we expect a signal at least two orders of magnitude larger compared to current schemes using surface implantation of recoil nuclei. The signal background is dominated by Cherenkov radiation induced by β decays of the thorium decay chain. We estimate that, even if the isomer undergoes radiative de-excitation with a probability of only 0.1%, the VUV γ ray can be detected within a reasonable measurement time.

  19. Characterization of organic contaminants in porous media using nuclear magnetic resonance and spectral induced polarization measurements.

    NASA Astrophysics Data System (ADS)

    Rupert, Y. K.

    2015-12-01

    The remediation and monitoring of soils and groundwater contaminated with organic compounds is an important goal of many environmental restoration efforts. This laboratory research focuses on combining two innovative geophysical methods: nuclear magnetic resonance (NMR) and spectral induced polarization (SIP) to assess their suitability to characterize and quantify organic contaminants in porous media. Toluene, a light non-aqueous phase liquid (LNAPL), and ethoxy-nonafluorobutane, an engineered dense non-aqueous phase liquid (DNAPL), have been selected as representative organic contaminants. Low-field NMR relaxation time (T2) measurements and diffusion-relaxation (D-T2) correlation measurements, as well as low frequency SIP measurements (<10 kHz) are performed to quantify the amount of these two organic compounds in the presence of water in three types of porous media (sands, clay, and various sand-clay mixtures). The T2, D-T2, and SIP measurements are made on water, toluene, and the synthetic DNAPL in each porous media to understand the effect of different porous media on the NMR and SIP responses in each fluid. We then plan to make measurements on water-organic mixtures with varied concentrations of organic compounds in each porous medium to resolve the NMR and SIP response of the organic contaminants from that of water and to quantify the amount of organic contaminants. Building a relationship between SIP and NMR signatures from organic contaminants not only provides a fundamental yet important petrophysical relationship, but also builds a framework for continued investigation into how these two methods synergize. This will also provide spatially dense information about organic contaminated natural sediments at scales that will improve the quantitative characterization and remediation of contaminated sites.The remediation and monitoring of soils and groundwater contaminated with organic compounds is an important goal of many environmental restoration efforts

  20. Heat Transfer in Waste Glass Melts - Measurement and Implications for Nuclear Waste Vitrification

    NASA Astrophysics Data System (ADS)

    Wang, Chuan

    Thermal properties of waste glass melts, such as high temperature density and thermal conductivity, are relevant to heat transfer processes in nuclear waste vitrification. Experimental measurement techniques were developed and applied to four nuclear waste glasses representative of those currently projected for treatment of Hanford HLW and LAW streams to study heat flow mechanisms in nuclear waste vitrification. Density measurement results by Archimedes' method indicated that densities of the melts investigated varied considerably with composition and temperature. Thermal diffusivities of waste melts were determined at nominal melter operating temperatures using a temperature-wave technique. Thermal conductivities were obtained by combining diffusivity data with the experimentally-acquired densities of the melts and their known heat capacities. The experimental results display quite large positive dependences of conductivities on temperature for some samples and much weaker positive temperature dependences for others. More importantly, there is observed a big change in the slopes of the conductivities versus temperature as temperature is increased for two of the melts, but not for the other two. This behavior was interpreted in terms of the changing contributions of radiation and conduction with temperature and composition dependence of the absorption coefficient. Based on the obtained thermal conductivities, a simple model for a waste glass melter was set up, which was used to analyze the relative contributions of conduction and radiation individually and collectively to the overall heat flow and to investigate factors and conditions that influence the radiation contribution to heat flow. The modeling results showed that unlike the case at lower temperatures, the radiant energy flow through waste melts could be predominant compared with conduction at temperature of about 900 °C or higher. However, heat flow due to radiation was roughly equal to that from

  1. Measurement of Atmospheric Sea Salt Concentration in the Dry Storage Facility of the Spent Nuclear Fuel

    SciTech Connect

    Masumi Wataru; Hisashi Kato; Satoshi Kudo; Naoko Oshima; Koji Wada; Hirofumi Narutaki

    2006-07-01

    Spent nuclear fuel coming from a Japanese nuclear power plant is stored in the interim storage facility before reprocessing. There are two types of the storage methods which are wet and dry type. In Japan, it is anticipated that the dry storage facility will increase compared with the wet type facility. The dry interim storage facility using the metal cask has been operated in Japan. In another dry storage technology, there is a concrete overpack. Especially in USA, a lot of concrete overpacks are used for the dry interim storage. In Japan, for the concrete cask, the codes of the Japan Society of Mechanical Engineers and the governmental technical guidelines are prepared for the realization of the interim storage as well as the code for the metal cask. But the interim storage using the concrete overpack has not been in progress because the evaluation on the stress corrosion cracking (SCC) of the canister is not sufficient. Japanese interim storage facilities would be constructed near the seashore. The metal casks and concrete overpacks are stored in the storage building in Japan. On the other hand, in USA they are stored outside. It is necessary to remove the decay heat of the spent nuclear fuel in the cask from the storage building. Generally, the heat is removed by natural cooling in the dry storage facility. Air including the sea salt particles goes into the dry storage facility. Concerning the concrete overpack, air goes into the cask body and cools the canister. Air goes along the canister surface and is in contact with the surface directly. In this case, the sea salt in the air attaches to the surface and then there is the concern about the occurrence of the SCC. For the concrete overpack, the canister including the spent fuel is sealed by the welding. The loss of sealability caused by the SCC has to be avoided. To evaluate the SCC for the canister, it is necessary to make clear the amount of the sea salt particles coming into the storage building and the

  2. Nuclear data for nuclear transmutation

    SciTech Connect

    Harada, Hideo

    2009-05-04

    Current status on nuclear data for the study of nuclear transmutation of radioactive wastes is reviewed, mainly focusing on neutron capture reactions. It is stressed that the highest-precision frontier research in nuclear data measurements should be a key to satisfy the target accuracies on the nuclear data requested for realizing the nuclear transmutation.

  3. Correlated biofilm imaging, transport and metabolism measurements via combined nuclear magnetic resonance and confocal microscopy.

    PubMed

    McLean, Jeffrey S; Ona, Ositadinma N; Majors, Paul D

    2008-02-01

    Bacterial biofilms are complex, three-dimensional communities found nearly everywhere in nature and are also associated with many human diseases. Detailed metabolic information is critical to understand and exploit beneficial biofilms as well as combat antibiotic-resistant, disease-associated forms. However, most current techniques used to measure temporal and spatial metabolite profiles in these delicate structures are invasive or destructive. Here, we describe imaging, transport and metabolite measurement methods and their correlation for live, non-invasive monitoring of biofilm processes. This novel combination of measurements is enabled by the use of an integrated nuclear magnetic resonance (NMR) and confocal laser scanning microscope (CLSM). NMR methods provide macroscopic structure, metabolic pathway and rate data, spatially resolved metabolite concentrations and water diffusion profiles within the biofilm. In particular, current depth-resolved spectroscopy methods are applied to detect metabolites in 140-190 nl volumes within biofilms of the dissimilatory metal-reducing bacterium Shewanella oneidensis strain MR-1 and the oral bacterium implicated in caries disease, Streptococcus mutans strain UA159. The perfused sample chamber also contains a transparent optical window allowing for the collection of complementary fluorescence information using a unique, in-magnet CLSM. In this example, the entire three-dimensional biofilm structure was imaged using magnetic resonance imaging. This was then correlated to a fluorescent CLSM image by employing a green fluorescent protein reporter construct of S. oneidensis. Non-invasive techniques such as described here, which enable measurements of dynamic metabolic processes, especially in a depth-resolved fashion, are expected to advance our understanding of processes occurring within biofilm communities. PMID:18253132

  4. Correlated biofilm imaging, transport and metabolism measurements via combined nuclear magnetic resonance and confocal microscopy

    PubMed Central

    McLean, Jeffrey S; Ona, Ositadinma N; Majors, Paul D

    2015-01-01

    Bacterial biofilms are complex, three-dimensional communities found nearly everywhere in nature and are also associated with many human diseases. Detailed metabolic information is critical to understand and exploit beneficial biofilms as well as combat antibiotic-resistant, disease-associated forms. However, most current techniques used to measure temporal and spatial metabolite profiles in these delicate structures are invasive or destructive. Here, we describe imaging, transport and metabolite measurement methods and their correlation for live, non-invasive monitoring of biofilm processes. This novel combination of measurements is enabled by the use of an integrated nuclear magnetic resonance (NMR) and confocal laser scanning microscope (CLSM). NMR methods provide macroscopic structure, metabolic pathway and rate data, spatially resolved metabolite concentrations and water diffusion profiles within the biofilm. In particular, current depth-resolved spectroscopy methods are applied to detect metabolites in 140–190 nl volumes within biofilms of the dissimilatory metal-reducing bacterium Shewanella oneidensis strain MR-1 and the oral bacterium implicated in caries disease, Streptococcus mutans strain UA159. The perfused sample chamber also contains a transparent optical window allowing for the collection of complementary fluorescence information using a unique, in-magnet CLSM. In this example, the entire three-dimensional biofilm structure was imaged using magnetic resonance imaging. This was then correlated to a fluorescent CLSM image by employing a green fluorescent protein reporter construct of S. oneidensis. Non-invasive techniques such as described here, which enable measurements of dynamic metabolic processes, especially in a depth-resolved fashion, are expected to advance our understanding of processes occurring within biofilm communities. PMID:18253132

  5. Measurement of soil carbon oxidation state and oxidative ratio by 13C nuclear magnetic resonance

    USGS Publications Warehouse

    Hockaday, W.C.; Masiello, C.A.; Randerson, J.T.; Smernik, R.J.; Baldock, J.A.; Chadwick, O.A.; Harden, J.W.

    2009-01-01

    The oxidative ratio (OR) of the net ecosystem carbon balance is the ratio of net O2 and CO2 fluxes resulting from photosynthesis, respiration, decomposition, and other lateral and vertical carbon flows. The OR of the terrestrial biosphere must be well characterized to accurately estimate the terrestrial CO2 sink using atmospheric measurements of changing O2 and CO2 levels. To estimate the OR of the terrestrial biosphere, measurements are needed of changes in the OR of aboveground and belowground carbon pools associated with decadal timescale disturbances (e.g., land use change and fire). The OR of aboveground pools can be measured using conventional approaches including elemental analysis. However, measuring the OR of soil carbon pools is technically challenging, and few soil OR data are available. In this paper we test three solid-state nuclear magnetic resonance (NMR) techniques for measuring soil OR, all based on measurements of the closely related parameter, organic carbon oxidation state (Cox). Two of the three techniques make use of a molecular mixing model which converts NMR spectra into concentrations of a standard suite of biological molecules of known C ox. The third technique assigns Cox values to each peak in the NMR spectrum. We assess error associated with each technique using pure chemical compounds and plant biomass standards whose Cox and OR values can be directly measured by elemental analyses. The most accurate technique, direct polarization solid-state 13C NMR with the molecular mixing model, agrees with elemental analyses to ??0.036 Cox units (??0.009 OR units). Using this technique, we show a large natural variability in soil Cox and OR values. Soil Cox values have a mean of -0.26 and a range from -0.45 to 0.30, corresponding to OR values of 1.08 ?? 0.06 and a range from 0.96 to 1.22. We also estimate the OR of the carbon flux from a boreal forest fire. Analysis of soils from nearby intact soil profiles imply that soil carbon losses associated

  6. Measurement of soil carbon oxidation state and oxidative ratio by 13C nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Hockaday, W. C.; Masiello, C. A.; Randerson, J. T.; Smernik, R. J.; Baldock, J. A.; Chadwick, O. A.; Harden, J. W.

    2009-06-01

    The oxidative ratio (OR) of the net ecosystem carbon balance is the ratio of net O2 and CO2 fluxes resulting from photosynthesis, respiration, decomposition, and other lateral and vertical carbon flows. The OR of the terrestrial biosphere must be well characterized to accurately estimate the terrestrial CO2 sink using atmospheric measurements of changing O2 and CO2 levels. To estimate the OR of the terrestrial biosphere, measurements are needed of changes in the OR of aboveground and belowground carbon pools associated with decadal timescale disturbances (e.g., land use change and fire). The OR of aboveground pools can be measured using conventional approaches including elemental analysis. However, measuring the OR of soil carbon pools is technically challenging, and few soil OR data are available. In this paper we test three solid-state nuclear magnetic resonance (NMR) techniques for measuring soil OR, all based on measurements of the closely related parameter, organic carbon oxidation state (Cox). Two of the three techniques make use of a molecular mixing model which converts NMR spectra into concentrations of a standard suite of biological molecules of known Cox. The third technique assigns Cox values to each peak in the NMR spectrum. We assess error associated with each technique using pure chemical compounds and plant biomass standards whose Cox and OR values can be directly measured by elemental analyses. The most accurate technique, direct polarization solid-state 13C NMR with the molecular mixing model, agrees with elemental analyses to ±0.036 Cox units (±0.009 OR units). Using this technique, we show a large natural variability in soil Cox and OR values. Soil Cox values have a mean of -0.26 and a range from -0.45 to 0.30, corresponding to OR values of 1.08 ± 0.06 and a range from 0.96 to 1.22. We also estimate the OR of the carbon flux from a boreal forest fire. Analysis of soils from nearby intact soil profiles imply that soil carbon losses associated

  7. US-Russian Cooperation in Upgrading MC&A System at Rosatom Facilities: Measurement of Nuclear Materials

    SciTech Connect

    Powell, Danny H; Jensen, Bruce A

    2011-01-01

    Improve protection of weapons-usable nuclear material from theft or diversion through the development and support of a nationwide sustainable and effective Material Control and Accountability (MC&A) program based on material measurement. The material protection, control, and accountability (MPC&A) cooperation has yielded significant results in implementing MC&A measurements at Russian nuclear facilities: (1) Establishment of MEM WG and MEMS SP; (2) Infrastructure for development, certification, and distribution of RMs; and (3) Coordination on development and implementation of MMs.

  8. 7Li relaxation time measurements at very low magnetic field by 1H dynamic nuclear polarization

    NASA Astrophysics Data System (ADS)

    Zeghib, Nadir; Grucker, Daniel

    2001-09-01

    Dynamic nuclear polarization (DNP) of water protons was used to measure the relaxation time of lithium at very low magnetic field as a demonstration of the use of DNP for nuclei less abundant than water protons. Lithium (Li+) was chosen because it is an efficient treatment for manic-depressive illness, with an unknown action mechanism. After having recalled the theoretical basis of a three-spin system comprising two nuclei - the water proton of the solvent, the dissolved Li+ ion and the free electron of a free radical - we have developed a transient solution in order to optimize potential biological applications of Li DNP. The three-spin model has allowed computation of all the parameters of the system - the longitudinal relaxation rate per unit of free radical concentration, the dipolar and scalar part of the coupling between the nuclei and the electron, and the maximum signal enhancement achievable for both proton and lithium spins. All these measurements have been obtained solely through the detection of the proton resonance.

  9. Statistical analyses of nuclear waste level measurements to estimate retained gas volumes

    NASA Astrophysics Data System (ADS)

    Whitney, Paul D.; Chen, Guang

    1999-01-01

    The Hanford site is home to 177 large, underground nuclear waste storage tanks. Numerous safety and environmental concerns around these tanks and their contents. One such concern is the propensity for the waste in these tanks to generate and retain flammable gases. The surface level of the waste in these tanks is routinely monitored to assess whether the tanks are leaking. For some of the tanks, the waste surface level measurements synchronously fluctuated with atmospheric pressure changes. The current best explanation for these synchronous fluctuations is that the waste contains gas-phase material that changes volume in response to the atmospheric pressure changes. This paper describes: (1) The exploratory data analysis that led to the discovery of the phenomena; (2) A physical mode based on the ideal gas law that explains the phenomena. Additionally, the model allows one to obtain estimates of the retained gas volume in the tank waste; (3) A statistical procedure for detecting retained gas based on the physical model and tank surface level measurements; and (4) A Kalman filter model for analyzing the dynamics of retained gas. It's also shown how the filter can be used to detect abrupt changes in the system.

  10. Establishing protective long term measures after severe nuclear accidents using multiple criteria.

    PubMed

    Papazoglou, I A; Kollas, J G

    1997-05-01

    This paper proposes a methodology supporting decisions on protective measures following severe nuclear accidents and demonstrates its use. A multicriteria decision analysis approach is adopted where value tradeoffs are postponed until the very last stage of the decision process. All feasible solutions are implicitly considered and evaluated in the chosen criteria. Technically inferior solutions are excluded. Only the non-dominated or efficient solutions forming the "efficient frontier" are retained and presented to the decision makers. Implementation of inefficient solutions is in this way avoided. A choice among the efficient solutions, although it implies value tradeoffs among the multiple criteria, avoids the direct and apriori assessment of preferences. An interactive computer package has been developed with which the decision maker can choose a point on the efficient frontier in the consequence space and immediately see the corresponding alternative in the decision space. The methodology is demonstrated through an application on the choice among possible protective measures in contaminated areas of the former USSR after the Chernobyl accident using as criteria the collective effective life-time dose received by the population and the cost associated with each possible decision. PMID:9106708

  11. High-pressure autoclave for multipurpose nuclear magnetic resonance measurements up to 10 MPa

    NASA Astrophysics Data System (ADS)

    Behr, W.; Haase, A.; Reichenauer, G.; Fricke, J.

    1999-05-01

    High-pressure nuclear magnetic resonance (NMR) is an established method in NMR spectroscopy: on-line coupling of high-performance liquid chromatography with NMR, for example, reveals structural information which cannot be obtained with any other method. However, applications has been focused solely on high-pressure NMR spectroscopy, even though high-pressure NMR imaging allows in situ studies of processes such as the fluid exchange in porous media. A versatile high-pressure autoclave for NMR imaging is described in this article. The autoclave allows measurements in any horizontal NMR imager using magnetic field coil systems with an inside diameter of more than 70 mm. Any sample with a diameter up to 28 mm and a length of about 200 mm can be investigated. The autoclave is constructed for operating pressures up to 10 MPa and is temperature controlled between 10 and 60 °C. The materials of the high-pressure cell which are the thermoplastic polyetheretherketon (PEEK) for the pressure tube and brass (63% Cu, 37% Zn) for the caps also permit investigations with aggressive fluids such as supercritical carbon dioxide. Inlet and outlet valves allow replacement of fluids and pressure variations in the autoclave during the NMR measurement. FLASH NMR images of the fluid exchange of methanol for liquid carbon dioxide in silica alcogels at 6.5 MPa are presented in order to demonstrate possible applications.

  12. The aftermath of the Fukushima nuclear accident: Measures to contain groundwater contamination.

    PubMed

    Gallardo, Adrian H; Marui, Atsunao

    2016-03-15

    Several measures are being implemented to control groundwater contamination at the Fukushima Daiichi Nuclear Plant. This paper presents an overview of work undertaken to contain the spread of radionuclides, and to mitigate releases to the ocean via hydrological pathways. As a first response, contaminated water is being held in tanks while awaiting treatment. Limited storage capacity and the risk of leakage make the measure unsustainable in the long term. Thus, an impervious barrier has been combined with a drain system to minimize the discharge of groundwater offshore. Caesium in seawater at the plant port has largely dropped, although some elevated concentrations are occasionally recorded. Moreover, a dissimilar decline of the radioactivity in fish could indicate additional sources of radionuclides intake. An underground frozen shield is also being constructed around the reactors. This structure would reduce inflows to the reactors and limit the interaction between fresh and contaminated waters. Additional strategies include groundwater abstraction and paving of surfaces to lower water levels and further restrict the mobilisation of radionuclides. Technical difficulties and public distrust pose an unprecedented challenge to the site remediation. Nevertheless, the knowledge acquired during the initial work offers opportunities for better planning and more rigorous decisions in the future. PMID:26789364

  13. The SPATE 8000 Thermo-Elastic Camera For Dynamic Stress Measurement On Nuclear Plant Components

    NASA Astrophysics Data System (ADS)

    Bream, R. G.; Gasper, B. C.; Lloyd, B. E.; Page, S. W. J.

    1987-04-01

    Structural dynamics for integrity assessment and condition monitoring of electrical power station plant can be approached using a variety of methods combining theoretical modelling with experimental measurements. In recent years experimental approaches have broadened to include non-contacting full-field response measurement techniques using laser holography and more recently, stress pattern analysis from thermal emission (SPATE) to obtain dynamic stress information. This paper presents two examples of the application of a SPATE 8000 camera system to the determination of the dynamic stress distributions on nuclear reactor components. In the first project a Magnox reactor compensating bellows unit was dynamically tested in the laboratory using an electromagnetic shaker to excite resonances in the frequency range 300 to 400Hz. The dynamic stress data collected is compared with finite element model prediction. The second example describes a similar modal response investigation performed on an AGR gas circulator inner casing ring which is designed to isolate the stress concentrations present. This test was carried out in the power station maintenance facility during a routine reactor overhaul.

  14. Method for non-intrusively identifying a contained material utilizing uncollided nuclear transmission measurements

    DOEpatents

    Morrison, John L.; Stephens, Alan G.; Grover, S. Blaine

    2001-11-20

    An improved nuclear diagnostic method identifies a contained target material by measuring on-axis, mono-energetic uncollided particle radiation transmitted through a target material for two penetrating radiation beam energies, and applying specially developed algorithms to estimate a ratio of macroscopic neutron cross-sections for the uncollided particle radiation at the two energies, where the penetrating radiation is a neutron beam, or a ratio of linear attenuation coefficients for the uncollided particle radiation at the two energies, where the penetrating radiation is a gamma-ray beam. Alternatively, the measurements are used to derive a minimization formula based on the macroscopic neutron cross-sections for the uncollided particle radiation at the two neutron beam energies, or the linear attenuation coefficients for the uncollided particle radiation at the two gamma-ray beam energies. A candidate target material database, including known macroscopic neutron cross-sections or linear attenuation coefficients for target materials at the selected neutron or gamma-ray beam energies, is used to approximate the estimated ratio or to solve the minimization formula, such that the identity of the contained target material is discovered.

  15. Correlated Biofilm Imaging, Transport and Metabolism Measurements via Combined Nuclear Magnetic Resonance and Confocal Microscopy

    SciTech Connect

    Mclean, Jeffrey S.; Ona, Ositadinma; Majors, Paul D.

    2008-02-18

    Bacterial biofilms are complex, three-dimensional, communities that are found nearly everywhere in nature1 and are being recognized as the cause of treatment-resistant infections1 2. Advanced methods are required to characterize their collective and spatial patterns of metabolism however most techniques are invasive or destructive. Here we describe the use of a combined confocal laser scanning microscopy (CLSM) and nuclear magnetic resonance (NMR) microscopy system to monitor structure, mass transport, and metabolism in active biofilms. Non-invasive NMR methods provide macroscopic structure along with spatially-resolved metabolite profiles and diffusion measurements. CLSM enables monitoring of cells by fluorescent protein reporters to investigate biofilm structure and gene expression concurrently. A planar sample chamber design facilitates depth-resolved measurements on 140 nL sample volumes under laminar flow conditions. The techniques and approaches described here are applicable to environmental and medically relevant microbial communities, thus providing key metabolic information for promoting beneficial biofilms and treating associated diseases.

  16. Method for Non-Intrusively Identifying a Contained Material Utilizing Uncollided Nuclear Transmission Measurements

    SciTech Connect

    Morrison, John L.; Stephens, Alan G.; Grover Blaine S.

    1999-02-26

    An improved nuclear diagnostic method identifies a contained target material by measuring on-axis, mono-energetic uncollided particle radiation transmitted through a target material for two penetrating radiation beam energies, and applying specially developed algorithms to estimate a ratio of macroscopic neutron cross-sections for the uncollided particle radiation at the two energies, where the penetrating radiation is a neutron beam, or a ratio of linear attenuation coefficients for the uncollided particle radiation at the two energies, where the penetrating radiation is a gamma-ray beam. Alternatively, the measurements are used to derive a minimization formula based on the macroscopic neutron cross-sections for the uncollided particle radiation at the two neutron beam energies, or the linear attenuation coefficients for the uncollided particle radiation at the two gamma-ray beam energies. A candidate target material database, including known macroscopic neutron cross-sections or linear attenuation coefficients for target materials at the selected neutron or gamma-ray beam energies, is used to approximate the estimated ratio or to solve the minimization formula, such that the identity of the contained target material is discovered.

  17. Compendium of the Environmental Measurements Laboratory's research projects related to the Chernobyl nuclear accident

    SciTech Connect

    Volchok, H L; Chieco, N

    1986-10-01

    Following the accident at the Chernobyl nuclear reactor power station in the USSR on April 26, 1986, the Environmental Measurements Laboratory (EML) initiated a number of research projects as follows: (1) selected sites in both the Deposition and Surface Air networks were alerted and their sampling protocols adjusted to accommodate the anticipated arrival times and activity concentrations of the Chernobyl debris; (2) a number of cooperative programs involving field work, sampling, analysis and data interpretation were set up with institutions and scientists in other countries; (3) EML's Regional Baseline Station at Chester, NJ, as well as the roof of the Laboratory in New York City, provided bases for sampling and measurements to study the radionuclide concentrations, radiation levels, physical characteristics and potential biological implications of the Chernobyl fallout on the northeastern United States; and (4) the resulting fallout from the Chernobyl accident provided an 'experiment of opportunity' in that it enabled us to study fresh fission product deposition using collection systems resurrected from the 1950's and 1960's for comparison with current state-of-the-art methodology. The 13 reports of this volume have been entered separately into the data base.

  18. Measuring microbial metabolism in atypical environments: Bentonite in used nuclear fuel storage.

    PubMed

    Stone, Wendy; Kroukamp, Otini; Moes, Ana; McKelvie, Jennifer; Korber, Darren R; Wolfaardt, Gideon M

    2016-01-01

    Genomics enjoys overwhelming popularity in the study of microbial ecology. However, extreme or atypical environments often limit the use of such well-established tools and consequently demand a novel approach. The bentonite clay matrix proposed for use in Deep Geological Repositories for the long-term storage of used nuclear fuel is one such challenging microbial habitat. Simple, accessible tools were developed for the study of microbial ecology and metabolic processes that occur within this habitat, since the understanding of the microbiota-niche interaction is fundamental to describing microbial impacts on engineered systems such as compacted bentonite barriers. Even when genomic tools are useful for the study of community composition, techniques to describe such microbial impacts and niche interactions should complement these. Tools optimised for assessing localised microbial activity within bentonite included: (a) the qualitative use of the resazurin-resorufin indicator system for redox localisation, (b) the use of a CaCl2 buffer for the localisation of pH, and (c) fluorometry for the localisation of precipitated sulphide. The use of the Carbon Dioxide Evolution Monitoring System was also validated for measuring microbial activity in desiccated and saturated bentonite. Finally, the buffering of highly-basic bentonite at neutral pH improved the success of isolation of microbial populations, but not DNA, from the bentonite matrix. Thus, accessible techniques were optimised for exploring microbial metabolism in the atypical environments of clay matrices and desiccated conditions. These tools have application to the applied field of used nuclear fuel management, as well as for examining the fundamental biogeochemical cycles active in sedimentary and deep geological environments. PMID:26578245

  19. Plutonium gamma-ray measurements for mutual reciprocal inspections of dismantled nuclear weapons

    SciTech Connect

    Koenig, Z.M.; Carlson, J.B.; Clark, D.; Gosnell, T.B.

    1995-07-01

    The O`Leary-Mikhailov agreement of March 1994 stated that the U.S. and the Russian Federation would engage in mutual reciprocal inspections (MRI) of fissile materials removed from dismantled nuclear weapons. It was decided to begin with the plutonium (Pu) removed from dismantled weapons and held in storage containers. Later discussions between U.S. and Russian technical experts led to the conclusion that, to achieve the O`Leary-Mikhailov objectives, Pu MRI would need to determine that the material in the containers has properties consistent with a nuclear-weapon component. Such a property is a {sup 240}Pu/{sup 239}Pu ratio consistent with weapons-grade material. One of the candidate inspection techniques under consideration for Pu MRI is to use a narrow region (630-670 keV) of the plutonium gamma-ray spectrum, taken with a high-purity germanium detector, to determine that it is weapons-grade plutonium as well as to estimate the minimum mass necessary to produce the observed gamma-ray intensity. We developed software (the Pu600 code) for instrument control and analysis especially for this purpose. In November 1994, U.S. and Russian scientists met at the Lawrence Livermore National Laboratory for joint experiments to evaluate candidate Pu MRI inspection techniques. In one of these experiments, gamma-ray intensities were measured from three unclassified weapons-grade plutonium source standards and one reactor-grade standard (21% {sup 240}pu). Using our software, we determined the {sup 240}Pu/{sup 239}Pu ratio of these standards to accuracies within {+-}10%, which is adequate for Pu MRI. The minimum mass estimates varied, as expected, directly with the exposed surface area of the standards.

  20. Solution of resource allocation problem for identification of cost-effective measures to reduce nuclear proliferation risks

    SciTech Connect

    Andrianov, A.; Kuptsov, I.

    2013-07-01

    This report presents a methodology of selection of cost-effective measures to reduce nuclear proliferation risks. The methodology relies on a graded security model used in practice in different applications. The method is based on the controlled finite Markov chain approach set in combination with discrete dynamic programming and MCDM (Multi Criteria Decision Making) techniques that enables the expert to select the cost-effective measures to reduce nuclear proliferation risks depending on availability of resources. The analysis performed with different number of possible measures confirms the conclusions that the implementation of extra-large costs may not produce the required effect, and the increase in resources above a certain level does not appear sensitive. Diversification in improving the effectiveness of other measures seems more rational and efficient for the whole system than the unlimited improvement of the effectiveness of only one measure.

  1. Measurement of soil water erosion in Africa: the potential support provided by nuclear techniques

    NASA Astrophysics Data System (ADS)

    Mabit, Lionel

    2010-05-01

    medium-term rates of soil redistribution integrating land use and climatic variability. FRN can be used to obtain average soil redistribution figures for time scales ranging from single events to many years of erosion processes, while direct erosion measurements are related to single rainfall events or rather short periods of time (e.g. erosion plots). FRN methodologies integrate all processes involving soil particle movements and allow quantification of soil loss and deposition associated with sheet erosion, which is difficult to assess using other conventional approaches. Sampling of individual points allows spatially distributed information on rates and patterns of soil redistribution. Also, one of the main advantages of the FRN is that time-consuming, costly maintenance, long-term monitoring programme and installations required by non isotopic and conventional methods can be avoided. Soil sampling can be completed in a short time and the site disturbance during sampling is minimal and does not interfere with seeding and cultivation operations. Since radionuclide-based measurements also provide information on the spatial distribution of erosion/sedimentation rates, they can be used to validate the results of distributed soil erosion models. The main purpose of this contribution is to present a synthetic overview of the usefulness in using nuclear techniques in Africa to investigate medium and short term soil erosion and sedimentation processes. Also, the advantages and limitations in using the FRN (137-Cs, 210-Pb and 7-Be) as soil redistribution tracer will be compared to other conventional water erosion methods. Keywords: Water erosion, conventional erosion assessment and measurement, nuclear techniques.

  2. Development of departmental standard for traceability of measured activity for I-131 therapy capsules used in nuclear medicine.

    PubMed

    Ravichandran, Ramamoorthy; Binukumar, Jp

    2011-01-01

    International Basic Safety Standards (International Atomic Energy Agency, IAEA) provide guidance levels for diagnostic procedures in nuclear medicine indicating the maximum usual activity for various diagnostic tests in terms of activities of injected radioactive formulations. An accuracy of ± 10% in the activities of administered radio-pharmaceuticals is being recommended, for expected outcome in diagnostic and therapeutic nuclear medicine procedures. It is recommended that the long-term stability of isotope calibrators used in nuclear medicine is to be checked periodically for their performance using a long-lived check source, such as Cs-137, of suitable activity. In view of the un-availability of such a radioactive source, we tried to develop methods to maintain traceability of these instruments, for certifying measured activities for human use. Two re-entrant chambers [(HDR 1000 and Selectron Source Dosimetry System (SSDS)] with I-125 and Ir-192 calibration factors in the Department of Radiotherapy were used to measure Iodine-131 (I-131) therapy capsules to establish traceability to Mark V isotope calibrator of the Department of Nuclear Medicine. Special nylon jigs were fabricated to keep I-131 capsule holder in position. Measured activities in all the chambers showed good agreement. The accuracy of SSDS chamber in measuring Ir-192 activities in the last 5 years was within 0.5%, validating its role as departmental standard for measuring activity. The above method is adopted because mean energies of I-131 and Ir-192 are comparable. PMID:21430859

  3. Measurement and Analysis of Gamma-Rays Emitted From Spent Nuclear Fuel Above 3 MeV

    SciTech Connect

    Rodriguez, Douglas C.; Anderson, Elaina R.; Anderson, Kevin K.; Campbell, Luke W.; Fast, James E.; Jarman, Kenneth D.; Kulisek, Jonathan A.; Orton, Christopher R.; Runkle, Robert C.; Stave, Sean C.

    2013-12-01

    The gamma-ray spectrum of spent nuclear fuel in the 3- to 6-MeV energy range is important for active interrogation since emitted gamma rays emitted from nuclear decay are not expected to interfere with measurements in this energy region. There is, unfortunately, a dearth of empirical measurements from spent nuclear fuel in this region. This work is an initial attempt to partially ll this gap by presenting an analysis of gamma-ray spectra collected from a set of spent nuclear fuel sources using a high-purity germanium detector array. This multi-crystal array possesses a large collection volume, providing high energy resolution up to 16 MeV. The results of these measurements establish the continuum count-rate in the energy region between 3- and 6-MeV. Also assessed is the potential for peaks from passive emissions to interfere with peak measurements resulting from active interrogation delayed emissions. As one of the first documented empirical measurements of passive emissions from spent fuel for energies above 3 MeV, this work provides a foundation for active interrogation model validation and detector development.

  4. Measurement and analysis of gamma-rays emitted from spent nuclear fuel above 3 MeV.

    PubMed

    Rodriguez, Douglas C; Anderson, Elaina; Anderson, Kevin K; Campbell, Luke W; Fast, James E; Jarman, Kenneth; Kulisek, Jonathan; Orton, Christopher R; Runkle, Robert C; Stave, Sean

    2013-12-01

    The gamma-ray spectrum of spent nuclear fuel in the 3-6 MeV energy range is important for active interrogation since gamma rays emitted from nuclear decay are not expected to interfere with measurements in this energy region. There is, unfortunately, a dearth of empirical measurements from spent nuclear fuel in this region. This work is an initial attempt to partially fill this gap by presenting an analysis of gamma-ray spectra collected from a set of spent nuclear fuel sources using a high-purity germanium detector array. This multi-crystal array possesses a large collection volume, providing high energy resolution up to 16 MeV. The results of these measurements establish the continuum count-rate in the energy region between 3 and 6 MeV. Also assessed is the potential for peaks from passive emissions to interfere with peak measurements resulting from active interrogation delayed emissions. As one of the first documented empirical measurements of passive emissions from spent fuel for energies above 3 MeV, this work provides a foundation for active interrogation model validation and detector development. PMID:24035928

  5. 137Cesium Exposure and Spirometry Measures in Ukrainian Children Affected by the Chernobyl Nuclear Incident

    PubMed Central

    Svendsen, Erik R.; Kolpakov, Igor E.; Stepanova, Yevgenia I.; Vdovenko, Vitaliy Y.; Naboka, Maryna V.; Mousseau, Timothy A.; Mohr, Lawrence C.; Hoel, David G.; Karmaus, Wilfried J.J.

    2010-01-01

    Background After the Chernobyl accident in 1986, children of the contaminated Narodichesky region of Ukraine were obliged to participate in a yearly medical screening. They have been exposed to 137cesium (137Cs; half-life = 30 years) in contaminated soils, air, and food. Objective Using a “natural experiment” approach and a longitudinal prospective cohort study design, we investigated the association of soil 137Cs and spirometry measures for 415 children using 1,888 repeated measurements from 1993 to 1998. Methods Mean baseline village soil 137Cs measurements, which varied from 29.0 to 879 kBq/m2, were used as exposure indicators. A standardized spirometry protocol and prediction equations specific to Ukrainian children were used by the same pulmonologist in all screenings. Results Children living in villages with the highest quintile of soil 137Cs were 2.60 times more likely to have forced vital capacity (FVC) < 80% of predicted [95% confidence interval (CI), 1.07–6.34] and 5.08 times more likely to have a ratio of forced expiratory volume in 1 sec (FEV1) to FVC% < 80% (95% CI, 1.02–25.19). We found statistically significant evidence of both airway obstruction (FEV1/FVC%, peak expiratory flow, and maximum expiratory flow at 25%, 50%, and 75% of FVC) and restriction (FVC) with increasing soil 137Cs. Conclusions These findings are unique and suggest significant airway obstruction and restriction consequences for children chronically exposed to low-dose radioactive contaminants such as those found downwind of the Chernobyl Nuclear Power Plant. PMID:20100677

  6. Ground-based air-sampling measurements near the Nevada Test Site after atmospheric nuclear tests.

    PubMed

    Cederwall, R T; Ricker, Y E; Cederwall, P L; Homan, D N; Anspaugh, L R

    1990-11-01

    Historical air-sampling data measured within 320 km (200 mi) of the Nevada Test Site (NTS) have been reviewed for periods following atmospheric nuclear tests, primarily in the 1950s. These data come mostly from high-volume air samplers, with some from cascade-impactor samplers. Measurements considered here are for beta radiation from gross fission products. The resulting air-quality data base is comprised of almost 13,000 samples from 42 sampling locations downwind of the NTS. In order to compile an accurate air-quality data base for use in estimating exposure via inhalation, raw data values were sought where possible, and the required calculations were performed on a computer with state-of-the-art algorithms. The data-processing procedures consisted of (1) entry and error checking of historical data; (2) determination of appropriate background values, air-sampling volumes, and net air concentrations; and (3) calculation of integrated air concentration (C) for each sample (considering fallout arrival times). Comparing C values for collocated high-volume and cascade-impactor samplers during the Upshot-Knothole series showed similar lognormal distributions, but with a geometric mean C for cascade impactors about half that for the high-volume air samplers. Overall, the uncertainty in C values is about a factor of three. In the past, it has been assumed that C could be related to ground deposition by a constant having units of velocity. In our data bases, simultaneous measurements of air concentration and ground deposition at the same locations were not related by a constant; indeed, there was a great amount of scatter. This suggests that the relationship between C and ground deposition in this situation is too complex to be treated adequately by simple approaches. PMID:2211113

  7. Ground-based air-sampling measurements near the Nevada Test Site after atmospheric nuclear tests

    SciTech Connect

    Cederwall, R.T.; Ricker, Y.E.; Cederwall, P.L.; Homan, D.N.; Anspaugh, L.R. )

    1990-11-01

    Historical air-sampling data measured within 320 km (200 mi) of the Nevada Test Site (NTS) have been reviewed for periods following atmospheric nuclear tests, primarily in the 1950s. These data come mostly from high-volume air samplers, with some from cascade-impactor samplers. Measurements considered here are for beta radiation from gross fission products. The resulting air-quality data base is comprised of almost 13,000 samples from 42 sampling locations downwind of the NTS. In order to compile an accurate air-quality data base for use in estimating exposure via inhalation, raw data values were sought where possible, and the required calculations were performed on a computer with state-of-the-art algorithms. The data-processing procedures consisted of (1) entry and error checking of historical data; (2) determination of appropriate background values, air-sampling volumes, and net air concentrations; and (3) calculation of integrated air concentration (C) for each sample (considering fallout arrival times). Comparing C values for collocated high-volume and cascade-impactor samplers during the Upshot-Knothole series showed similar lognormal distributions, but with a geometric mean C for cascade impactors about half that for the high-volume air samplers. Overall, the uncertainty in C values is about a factor of three. In the past, it has been assumed that C could be related to ground deposition by a constant having units of velocity. In our data bases, simultaneous measurements of air concentration and ground deposition at the same locations were not related by a constant; indeed, there was a great amount of scatter. This suggests that the relationship between C and ground deposition in this situation is too complex to be treated adequately by simple approaches.

  8. Robust determination of surface relaxivity from nuclear magnetic resonance DT2 measurements

    NASA Astrophysics Data System (ADS)

    Luo, Zhi-Xiang; Paulsen, Jeffrey; Song, Yi-Qiao

    2015-10-01

    Nuclear magnetic resonance (NMR) is a powerful tool to probe into geological materials such as hydrocarbon reservoir rocks and groundwater aquifers. It is unique in its ability to obtain in situ the fluid type and the pore size distributions (PSD). The T1 and T2 relaxation times are closely related to the pore geometry through the parameter called surface relaxivity. This parameter is critical for converting the relaxation time distribution into the PSD and so is key to accurately predicting permeability. The conventional way to determine the surface relaxivity ρ2 had required independent laboratory measurements of the pore size. Recently Zielinski et al. proposed a restricted diffusion model to extract the surface relaxivity from the NMR diffusion-T2 relaxation (DT2) measurement. Although this method significantly improved the ability to directly extract surface relaxivity from a pure NMR measurement, there are inconsistencies with their model and it relies on a number of preset parameters. Here we propose an improved signal model to incorporate a scalable LT and extend their method to extract the surface relaxivity based on analyzing multiple DT2 maps with varied diffusion observation time. With multiple diffusion observation times, the apparent diffusion coefficient correctly describes the restricted diffusion behavior in samples with wide PSDs, and the new method does not require predetermined parameters, such as the bulk diffusion coefficient and tortuosity. Laboratory experiments on glass beads packs with the beads diameter ranging from 50 μm to 500 μm are used to validate the new method. The extracted diffusion parameters are consistent with their known values and the determined surface relaxivity ρ2 agrees with the expected value within ±7%. This method is further successfully applied on a Berea sandstone core and yields surface relaxivity ρ2 consistent with the literature.

  9. Robust determination of surface relaxivity from nuclear magnetic resonance DT(2) measurements.

    PubMed

    Luo, Zhi-Xiang; Paulsen, Jeffrey; Song, Yi-Qiao

    2015-10-01

    Nuclear magnetic resonance (NMR) is a powerful tool to probe into geological materials such as hydrocarbon reservoir rocks and groundwater aquifers. It is unique in its ability to obtain in situ the fluid type and the pore size distributions (PSD). The T1 and T2 relaxation times are closely related to the pore geometry through the parameter called surface relaxivity. This parameter is critical for converting the relaxation time distribution into the PSD and so is key to accurately predicting permeability. The conventional way to determine the surface relaxivity ρ2 had required independent laboratory measurements of the pore size. Recently Zielinski et al. proposed a restricted diffusion model to extract the surface relaxivity from the NMR diffusion-T2 relaxation (DT2) measurement. Although this method significantly improved the ability to directly extract surface relaxivity from a pure NMR measurement, there are inconsistencies with their model and it relies on a number of preset parameters. Here we propose an improved signal model to incorporate a scalable LT and extend their method to extract the surface relaxivity based on analyzing multiple DT2 maps with varied diffusion observation time. With multiple diffusion observation times, the apparent diffusion coefficient correctly describes the restricted diffusion behavior in samples with wide PSDs, and the new method does not require predetermined parameters, such as the bulk diffusion coefficient and tortuosity. Laboratory experiments on glass beads packs with the beads diameter ranging from 50 μm to 500 μm are used to validate the new method. The extracted diffusion parameters are consistent with their known values and the determined surface relaxivity ρ2 agrees with the expected value within ±7%. This method is further successfully applied on a Berea sandstone core and yields surface relaxivity ρ2 consistent with the literature. PMID:26340435

  10. Variational versus Perturbational Treatment of Spin-Orbit Coupling in Relativistic Density Functional Calculations of Electronic g Factors: Effects from Spin-Polarization and Exact Exchange.

    PubMed

    Verma, Prakash; Autschbach, Jochen

    2013-02-12

    Different approaches are compared for relativistic calculations of electronic g factors of molecules with light atoms, transition metal complexes, and selected complexes with actinides, using density functional theory (DFT) and Hartree-Fock (HF) theory. The comparison includes functionals with range-separated exchange. Within the variationally stable zeroth-order regular approximation (ZORA) relativistic framework, g factors are obtained with a linear response (LR) method where spin-orbit (SO) coupling is treated as a linear perturbation, a spin-polarized approach based on magnetic anisotropy (MA) that includes SO coupling variationally, and a quasi-restricted variational SO method previously devised by van Lenthe, van der Avoird, and Wormer (LWA). The MA and LWA approaches were implemented in the open-source NWChem quantum chemistry package. We address the importance of electron correlation (DFT vs HF), the importance of including spin polarization in the g tensor methodology, the question of whether the use of nonrelativistic spin density functionals is adequate for such calculations, and the importance of treating spin-orbit coupling beyond first-order. For selected systems, the extent of the DFT delocalization error is explicitly investigated via calculations of the energy as a function of fractional electron numbers. For a test set of small molecules with light main group atoms, all levels of calculation perform adequately as long as there is no energetic near-degeneracy among occupied and unoccupied orbitals. The interplay between different factors determining the accuracy of calculated g factors becomes more complex for systems with heavy elements such as third row transition metals and actinides. The MA approach is shown to perform acceptably well for a wide range of scenarios. PMID:26588748

  11. Tuning g-factor of electrons through spin-orbit coupling in GaAs/AlGaAs conical quantum dots

    NASA Astrophysics Data System (ADS)

    Prabhakar, Sanjay; Melnik, Roderick

    2016-03-01

    We investigate band structures of GaAs/Al0.3Ga0.7As three-dimensional conical quantum dots (QDs). In particular, we explore the influence of the Rashba and Dresselhaus spin-orbit couplings in the variation of effective g-factor of electrons in such QDs. We demonstrate that the interplay between the Rashba and Dresselhaus spin-orbit couplings can provide further insight into underlying physical phenomena and assist in the design of quantum logic gates for the application in spintronic devices.

  12. Nuclear spin dependence of the reaction of H(3)+ with H2. II. Experimental measurements.

    PubMed

    Crabtree, Kyle N; Kauffman, Carrie A; Tom, Brian A; Beçka, Eftalda; McGuire, Brett A; McCall, Benjamin J

    2011-05-21

    The nuclear spin dependence of the chemical reaction H(3)(+)+ H(2) → H(2) + H(3)(+) has been studied in a hollow cathode plasma cell. Multipass infrared direct absorption spectroscopy has been employed to monitor the populations of several low-energy rotational levels of ortho- and para-H(3)(+) (o-H(3)(+) and p-H(3)(+)) in hydrogenic plasmas of varying para-H(2) (p-H(2)) enrichment. The ratio of the rates of the proton hop (k(H)) and hydrogen exchange (k(E)) reactions α ≡ k(H)/k(E) is inferred from the observed p-H(3)(+) fraction as a function of p-H(2) fraction using steady-state chemical models. Measurements have been performed both in uncooled (T(kin) ∼ 350 K) and in liquid-nitrogen-cooled (T(kin) ∼ 135 K) plasmas, marking the first time this reaction has been studied at low temperature. The value of α has been found to decrease from 1.6 ± 0.1 at 350 K to 0.5 ± 0.1 at 135 K. PMID:21599063

  13. Measurement of Nuclear Recoils in the CDMS II Dark Matter Search

    SciTech Connect

    Fallows, Scott Mathew

    2014-12-01

    The Cryogenic Dark Matter Search (CDMS) experiment is designed to directly detect elastic scatters of weakly-interacting massive dark matter particles (WIMPs), on target nuclei in semiconductor crystals composed of Si and Ge. These scatters would occur very rarely, in an overwhelming background composed primarily of electron recoils from photons and electrons, as well as a smaller but non-negligible background of WIMP-like nuclear recoils from neutrons. The CDMS II generation of detectors simultaneously measure ionization and athermal phonon signals from each scatter, allowing discrimination against virtually all electron recoils in the detector bulk. Pulse-shape timing analysis allows discrimination against nearly all remaining electron recoils taking place near detector surfaces. Along with carefully limited neutron backgrounds, this experimental program allowed for \\background- free" operation of CDMS II at Soudan, with less than one background event expected in each WIMP-search analysis. As a result, exclusionary upper-limits on WIMP-nucleon interaction cross section were placed over a wide range of candidate WIMP masses, ruling out large new regions of parameter space.

  14. /sup 31/P nuclear magnetic resonance measurements of intracellular pH in giant barnacle muscle

    SciTech Connect

    Hamm, J.R.; Yue, G.M.

    1987-01-01

    The accuracy of intracellular pH (pH/sub i/) measurements by /sup 31/P nuclear magnetic resonance (NMR) spectroscopy was examined in single muscle fibers from the giant barnacle, Balanus nubilis. The pH/sub i/ was derived from the chemical shifts of 2-deoxy-D-glucose-6-phosphate and inorganic phosphate. In fibers superfused with sea water at pH 7.7, pH/sub i/ = 7.30 +/- 0.02 at 20/sup 0/C. Experimentally induced pH/sub i/ changes were followed with a time resolution of 3 min. Intracellular alkalinization was induced by exposure to NH/sub 3/Cl and intracellular acidification followed when NH/sub 3/ was removed. Then acid extrusion was stimulated by exposure to bicarbonate containing sea water. In single muscle fibers /sup 31/P NMR results were in excellent agreement with microelectrode studies over the pH range of 6.5 to 8.0. The initial acid extrusion rate was 1.7 +/- 0.3 mmol x 1/sup -1/ x min/sup -1/ at pH/sub i/ 6.75. The authors results showed that /sup 31/P NMR is a reliable in vivo pH probe.

  15. 31P nuclear magnetic resonance measurements of intracellular pH in giant barnacle muscle.

    PubMed

    Hamm, J R; Yue, G M

    1987-01-01

    The accuracy of intracellular pH (pHi) measurements by 31P nuclear magnetic resonance (NMR) spectroscopy was examined in single muscle fibers from the giant barnacle, Balanus nubilis. The pHi was derived from the chemical shifts of 2-deoxy-D-glucose-6-phosphate and inorganic phosphate. In fibers superfused with sea water at pH 7.7, pHi = 7.30 +/- 0.02 at 20 degrees C. Experimentally induced pHi changes were followed with a time resolution of 3 min. Intracellular alkalinization was induced by exposure to NH4Cl and intracellular acidification followed when NH3 was removed. Then acid extrusion was stimulated by exposure to bicarbonate containing sea water. In single muscle fibers 31P NMR results were in excellent agreement with microelectrode studies over the pH range of 6.5 to 8.0. The initial acid extrusion rate was 1.7 +/- 0.3 mmol X l-1 X min-1 at pHi 6.75. Our results showed that 31P NMR is a reliable in vivo pH probe. PMID:3812665

  16. Direct Measurement of Surface Dissolution Rates in Potential Nuclear Waste Forms: The Example of Pyrochlore.

    PubMed

    Fischer, Cornelius; Finkeldei, Sarah; Brandt, Felix; Bosbach, Dirk; Luttge, Andreas

    2015-08-19

    The long-term stability of ceramic materials that are considered as potential nuclear waste forms is governed by heterogeneous surface reactivity. Thus, instead of a mean rate, the identification of one or more dominant contributors to the overall dissolution rate is the key to predict the stability of waste forms quantitatively. Direct surface measurements by vertical scanning interferometry (VSI) and their analysis via material flux maps and resulting dissolution rate spectra provide data about dominant rate contributors and their variability over time. Using pyrochlore (Nd2Zr2O7) pellet dissolution under acidic conditions as an example, we demonstrate the identification and quantification of dissolution rate contributors, based on VSI data and rate spectrum analysis. Heterogeneous surface alteration of pyrochlore varies by a factor of about 5 and additional material loss by chemo-mechanical grain pull-out within the uppermost grain layer. We identified four different rate contributors that are responsible for the observed dissolution rate range of single grains. Our new concept offers the opportunity to increase our mechanistic understanding and to predict quantitatively the alteration of ceramic waste forms. PMID:26186697

  17. Measurement of nuclear recoil quenching factors in CaWO 4

    NASA Astrophysics Data System (ADS)

    Jagemann, Th.; Feilitzsch, F. v.; Hagn, H.; Jochum, J.; Potzel, W.; Rau, W.; Stark, M.; Westphal, W.

    2006-11-01

    The CRESST experiment, aiming at the direct detection of WIMPs via nuclear recoils, is currently using scintillating CaWO4 crystals. The WIMP-nucleus cross section for elastic scattering as well as the scintillation efficiency differ considerably for recoils from Ca, W and O in these crystals. Therefore a discriminating detector calibration is essential in order to improve WIMP parameter claims. At the tandem accelerator of the Maier-Leibnitz-Laboratory (MLL) in Garching, Germany, a neutron scattering facility is operated for the determination of the individual quenching factors (QF) in the bulk of a CaWO4 crystal to better understand the detector response to neutron background and a possible WIMP signal. First measurements at room temperature reveal QF(O) = 7.8 ± 0.3% (recoil energy 1.0-2.2 MeV), QF(Ca) = 6.3 ± 1.6% (recoil energy 0.4-1 MeV), QF(W) < 3.0% (2σ, recoil energy 0.1 MeV).

  18. Sorption (Kd) measurements in support of dose assessments for Zion Nuclear Station Decommissioning

    SciTech Connect

    Yim S. P.; Sullivan T.; Milian, L.

    2012-12-12

    The Zion Nuclear Power Station is being decommissioned. ZionSolutions proposes to leave much of the below grade structures in place and to fill them with “clean” concrete demolition debris from the above grade parts of the facility. This study, commissioned by ZionSolutions and conducted by the Brookhaven National Laboratory (BNL) was performed to provide site-specific data for performance assessment calculations to support the request to terminate the NRC license and allow unrestricted use of the facility. Specifically, this study measured the distribution coefficient for five radionuclides of concern using site-specific soils and groundwater. The distributions coefficient is a measure of the amount of the radionuclide that will remain sorbed to the soil or concrete that is present relative to the amount that will remain in solution. A high distribution coefficient indicates most of the radionuclide will remain on the solid material and will not be available for transport by the groundwater. The radionuclides of concern are Fe-55, Co-60, Ni-63, Sr-90, and Cs-137. Tests were performed following ASTM C1733-10, Standard Test Methods for Distribution Coefficients of Inorganic Species by the Batch Method. Sr-85 was used in the testing as an analogue for Sr-90 because it behaves similarly with respect to sorption and has a gamma emission that is easier to detect than the beta emission from Sr-90. Site-specific soils included disturbed sand (sand removed during construction and used as backfill), native sand, silt/clay and silt. In addition, concrete cores from the Unit-1 Containment Building and the Crib House were broken into particles less than 2 mm in size and tested to obtain distribution coefficients for the five nuclides.

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

    SciTech Connect

    Avignone, F.T. III

    1982-02-28

    Research progress in briefly described, and details are presented in the attached preprints and reprints: (1) precision mass differences in light rubidium and krypton isotopes utilizing beta endpoint measurements; (2) precision mass measurements utilizing beta endpoints; (3) Monte Carlo calculations predicting the response of intrinsic GE detectors to electrons and positrons; and (4) reactor antineutrino spectra and nuclear spectroscopy of isotopes far from beta stability. (WHK)

  20. Measurements and Effects of the Raman Active Nuclear Distribution in the Condensed Phase

    NASA Astrophysics Data System (ADS)

    Palese, Stephen Paul

    1995-01-01

    energy relaxation processes. For the conjugated polymer system, the nuclear distribution extracted from the Kerr effect studies is compared to calculated and experimentally measured excited state dynamics. It is found that the time scale of energy relaxation, obtained from resonant experiments with excitation below the absorption edge, is consistent with the extracted nuclear distribution. These experiments, in conjunction with other investigations, indicate that both electron -electron and electron-phonon coupling are important in such systems.

  1. Nuclear Spin Orientation Dependence of Magnetoconductance: A New Method for Measuring the Spin of Charged Excitations in the QHE

    SciTech Connect

    Bowers, C.R.; Reno, J.L.; Simmons, J.A.; Vitkalov, S.A.

    1998-12-01

    A new method for measuring the spin of the electrically charged ground state excitations m the Q$j~j quantum Hall effect ia proposed and demonstmted for the tirst time in GaAs/AIGaAs nndtiquantum wells. The method is &sed on the nuclear spin orientation dependence of" the 2D dc conductivity y in the quantum Hall regime due to the nuclear hyperfine interaction. As a demonstration of this method the spin of the electrically charged excitations of the ground state is determined at filling factor v = 1.

  2. Measurement of hetero-nuclear distances using a symmetry-based pulse sequence in solid-state NMR.

    PubMed

    Chen, Lei; Wang, Qiang; Hu, Bingwen; Lafon, Olivier; Trébosc, Julien; Deng, Feng; Amoureux, Jean-Paul

    2010-08-28

    A Symmetry-based Resonance-Echo DOuble-Resonance (S-REDOR) method is proposed for measuring hetero-nuclear dipolar couplings between two different spin-1/2 nuclei, under fast magic-angle spinning. The hetero-nuclear dipolar couplings are restored by employing the SR4 sequence, which requires the rf-field strength to be only twice the spinning frequency. The S-REDOR experiment is extended to S-RESPDOR (Symmetry-based Resonance-Echo Saturation-Pulse DOuble-Resonance) for determining dipolar coupling between a spin-1/2 nucleus (e.g.(13)C) and (14)N. It is demonstrated that S-REDOR and S-RESPDOR methods suppress efficiently the homo-nuclear dipolar interaction of the irradiated nucleus and benefit from high robustness to the rf-field inhomogeneity, chemical shielding and dipolar truncation. Therefore, these methods allow the measurement of (13)C/(14,15)N distances, with (13)C observation, in uniformly (13)C-labeled samples. Furthermore, we provide analytical solutions for the S-REDOR and S-RESPDOR dephasing curves. These solutions facilitate the measurement of hetero-nuclear distances from experimental data. PMID:20577687

  3. Genetics and g-factors.

    SciTech Connect

    Julian, S. R.; Norman , M. R.

    2011-03-01

    Every metal has a Fermi surface, which gives rise to quantum oscillations in a magnetic field. But the nature of the Fermi surface in cuprate superconductors is a profound mystery that scientists are only starting to unravel.

  4. Simultaneous measurement of resistively and optically detected nuclear magnetic resonance in the ν =2 /3 fractional quantum Hall regime

    NASA Astrophysics Data System (ADS)

    Akiba, Keiichirou; Nagase, Katsumi; Hirayama, Yoshiro

    2016-08-01

    We observe nuclear magnetic resonance (NMR) in the fractional quantum Hall regime at the Landau-level filling factor of ν =2 /3 from simultaneous measurement of longitudinal resistance and photoluminescence (PL). The dynamic nuclear-spin polarization is induced by applying a huge electronic current at the spin phase transition point of ν =2 /3 . The NMR spectra obtained from changes in resistance and PL intensity are qualitatively the same; that is, the Knight-shift (spin-polarized region) and zero-shift (spin-unpolarized region) resonances are observed in both. The observed change in PL intensity is interpreted as a consequence of the trion scattering induced by polarized nuclear spins. We conclude that both detection methods probe almost the same local phenomena.

  5. Overview of a FPGA-based nuclear instrumentation dedicated to primary activity measurements.

    PubMed

    Bobin, C; Bouchard, J; Pierre, S; Thiam, C

    2012-09-01

    In National Metrology Institutes like LNE-LNHB, renewal and improvement of the instrumentation is an important task. Nowadays, the current trend is to adopt digital boards, which present numerous advantages over the standard electronics. The feasibility of an on-line fulfillment of nuclear-instrumentation functionalities using a commercial FPGA-based (Field-Programmable Gate Array) board has been validated in the case of TDCR primary measurements (Triple to Double Coincidence Ratio method based on liquid scintillation). The new applications presented in this paper have been included to allow either an on-line processing of the information or a raw-data acquisition for an off-line treatment. Developed as a complementary tool for TDCR counting, a time-to-digital converter specifically designed for this technique has been added. In addition, the description is given of a spectrometry channel based on the connection between conventional shaping amplifiers and the analog-to-digital converter (ADC) input available on the same digital board. First results are presented in the case of α- and γ-counting related to, respectively, the defined solid angle and well-type NaI(Tl) primary activity techniques. The combination of two different channels (liquid scintillation and γ-spectrometry) implementing the live-time anticoincidence processing is also described for the application of the 4πβ-γ coincidence method. The need for an optimized coupling between the analog chain and the ADC stage is emphasized. The straight processing of the signals delivered by the preamplifier connected to a HPGe detector is also presented along with the first development of digital filtering. PMID:22405958

  6. Measures of the environmental footprint of the front end of the nuclear fuel cycle

    SciTech Connect

    E. Schneider; B. Carlsen; E. Tavrides; C. van der Hoeven; U. Phathanapirom

    2013-11-01

    Previous estimates of environmental impacts associated with the front end of the nuclear fuel cycle (FEFC) have focused primarily on energy consumption and CO2 emissions. Results have varied widely. This work builds upon reports from operating facilities and other primary data sources to build a database of front end environmental impacts. This work also addresses land transformation and water withdrawals associated with the processes of the FEFC. These processes include uranium extraction, conversion, enrichment, fuel fabrication, depleted uranium disposition, and transportation. To allow summing the impacts across processes, all impacts were normalized per tonne of natural uranium mined as well as per MWh(e) of electricity produced, a more conventional unit for measuring environmental impacts that facilitates comparison with other studies. This conversion was based on mass balances and process efficiencies associated with the current once-through LWR fuel cycle. Total energy input is calculated at 8.7 x 10- 3 GJ(e)/MWh(e) of electricity and 5.9 x 10- 3 GJ(t)/MWh(e) of thermal energy. It is dominated by the energy required for uranium extraction, conversion to fluoride compound for subsequent enrichment, and enrichment. An estimate of the carbon footprint is made from the direct energy consumption at 1.7 kg CO2/MWh(e). Water use is likewise dominated by requirements of uranium extraction, totaling 154 L/MWh(e). Land use is calculated at 8 x 10- 3 m2/MWh(e), over 90% of which is due to uranium extraction. Quantified impacts are limited to those resulting from activities performed within the FEFC process facilities (i.e. within the plant gates). Energy embodied in material inputs such as process chemicals and fuel cladding is identified but not explicitly quantified in this study. Inclusion of indirect energy associated with embodied energy as well as construction and decommissioning of facilities could increase the FEFC energy intensity estimate by a factor of up

  7. Measuring and modeling intraocular light scatter with Shack-Hartmann wavefront sensing and the effects of nuclear cataract on the measurement of wavefront error

    NASA Astrophysics Data System (ADS)

    Donnelly, William J., III

    Purpose. The purpose of this research is to determine if Shack/Hartmann (S/H) wavefront sensing (SHWS) can be used to objectively quantify ocular forward scatter. Methods. Patient S/H images from an study of nuclear cataract were analyzed to extract scattering data by examining characteristics of the lenslet point spread functions. Physical and computer eye models with simulated cataract were developed to control variables and to test the underlying assumptions for using SHWS to measure aberrations and light scatter from nuclear cataract. Results. (1) For patients with nuclear opalescence (NO) >=2.5, forward scatter metrics in a multiple regression analysis account for 33% of variance in Mesopic Low Contrast acuity. Prediction of visual acuity was improved by employing a multiple regression analysis that included both backscatter and forward scatter metrics (R2 = 51%) for Mesopic High Contrast acuity. (2) The physical and computer models identified areas of instrument noise (e.g., stray light and unwanted reflections) improving the design of a second generation SHWS for measuring both wavefront error and scatter. (3) Exposure time had the most influence on, and pupil size had negligible influence on forward scatter metrics. Scatter metric MAX_SD predicted changes in simulated cataract up to R2 = 92%. There were small but significant differences (alpha = 0.05) between 1.5-pass and 1-pass wavefront measurements inclusive of variable simulated nuclear cataract and exposure; however, these differences were not visually significant. Improvements to the SHWS imaging hardware, software, and test protocol were implemented in a second generation SHWS to be used in a longitudinal cataract study. Conclusions. Forward light scatter in real eyes can be quantified using a SHWS. In the presence of clinically significant nuclear opalescence, forward scatter metrics predicted acuity better than the LOCS III NO backscatter metric. The superiority of forward scatter metrics over back

  8. [Medical and psychological aspects of safety measures maintenance among nuclear and power station personnel].

    PubMed

    Ipatov, P L; Sorokin, A V; Basov, V I

    2004-01-01

    The article deals with 15-year experience of medical and psychophysiologic service in Medical and Sanitary Establishment No. 156 and Balakovo nuclear power station on providing reliability of occupational activities for the station personnel. PMID:15124389

  9. Isotope-shift measurements of stable and short-lived lithium isotopes for nuclear-charge-radii determination

    SciTech Connect

    Noertershaeuser, W.; Sanchez, R.; Ewald, G.; Dax, A.; Goette, S.; Kluge, H.-J.; Kuehl, Th.; Wojtaszek, A.; Behr, J.; Bricault, P.; Dilling, J.; Dombsky, M.; Lassen, J.; Levy, C. D. P.; Pearson, M.; Bushaw, B. A.; Drake, G. W. F.; Pachucki, K.; Puchalski, M.; Yan, Z.-C.

    2011-01-15

    Changes in the mean square nuclear charge radii along the lithium isotopic chain were determined using a combination of precise isotope shift measurements and theoretical atomic structure calculations. Nuclear charge radii of light elements are of high interest due to the appearance of the nuclear halo phenomenon in this region of the nuclear chart. During the past years we have developed a laser spectroscopic approach to determine the charge radii of lithium isotopes which combines high sensitivity, speed, and accuracy to measure the extremely small field shift of an 8-ms-lifetime isotope with production rates on the order of only 10 000 atoms/s. The method was applied to all bound isotopes of lithium including the two-neutron halo isotope {sup 11}Li at the on-line isotope separators at GSI, Darmstadt, Germany, and at TRIUMF, Vancouver, Canada. We describe the laser spectroscopic method in detail, present updated and improved values from theory and experiment, and discuss the results.

  10. The incentives and feasibility for direct measurement of spent nuclear fuel characteristics in the Federal Waste Management System

    SciTech Connect

    Not Available

    1989-08-01

    The purpose of this work is to assess the nature and extent of the need for direct measurements of spent fuel characteristics within the utility and federal portions of the waste management system, and to evaluate the capability and limitations of various measurement devices for meeting those needs. The need for direct measurement is evaluated relative to the alternative sources of the spent fuel characteristics data required for the safe and effective operation of the system. The results of this work are intended to support Federal Waste Management System (FWMS) planners by identifying the probable and potential requirements for direct measurements and for making related programmatic decisions based on the adequacy or development requirements for appropriate measurement technologies to support the needs of facility and equipment designers and operators. The designers and operators of the FWMS need to know the characteristics of the spent nuclear fuel (SNF) and related wastes that will be handled, processed, stored, transported and ultimately emplaced underground for final disposal. There are typically two basic sources of this needed information: (1) historical records of measurements made when the fuel was being fabricated or was producing energy; and (2) direct measurements made during handling prior to disposal. Historical records would include the design and fabrication records of the nuclear fuel assemblies and the subsequent utility records of reactor and core operations. 21 refs., 3 figs., 5 tabs.

  11. Measurement of the Charge and Light Yield of Low Energy Nuclear Recoils in Liquid Xenon at Different Electric Fields

    NASA Astrophysics Data System (ADS)

    Anthony, Matthew; Aprile, Elena; de Perio, Patrick; Goetzke, Luke; Greene, Zach; Lin, Qing; Messina, Marcello; Plante, Guillaume; Rizzo, Alfio; Zhang, Yun

    2016-03-01

    Dual-phase liquid xenon detectors continue to lead in the search for the direct detection of dark matter. Characterization of the response of liquid xenon to low energy (<= 20 keV) nuclear recoils is essential to establish the sensitivity of these detectors to dark matter. The neriX detector at Columbia University is a dual-phase time projection chamber that is optimized for simultaneous measurements of light and charge from these low-energy interactions. A coincidence technique is employed to extract the light and charge yield from nuclear recoils in liquid xenon as a function of energy deposited and applied electric field. In this talk, we will present preliminary results from the light and charge yield measurements. We acknowledge continued support of the XENON Dark Matter program at Columbia University by the National Science Foundation.

  12. Sound velocity measurement of nuclear-ordered U2D2 solid 3He along the melting curve

    NASA Astrophysics Data System (ADS)

    Nomura, R.; Suzuki, M.; Yamaguchi, M.; Sasaki, Y.; Mizusaki, T.

    2000-05-01

    The sound velocity of a single-domain 3He crystal was measured in the nuclear-ordered low-field phase and the paramagnetic phase along the melting curve, using 10.98 MHz longitudinal sound. The temperature dependence of the sound velocity along the melting curve was explained by a nuclear spin contribution and the molar volume change along the melting curve. By comparing the measured velocity with thermodynamic quantities, we extracted the Grüneizen constant for the exchange energy. The anisotropy of the velocity in the ordered phase was investigated for three samples and was found to be smaller than 2×10 -5 in Δ v/ v. The attenuation coefficient of the sound was much smaller than 0.2 cm-1.

  13. Development of Measurement Methods for Detection of Special Nuclear Materials using D-D Pulsed Neutron Source

    NASA Astrophysics Data System (ADS)

    Misawa, Tsuyoshi; Takahashi, Yoshiyuki; Yagi, Takahiro; Pyeon, Cheol Ho; Kimura, Masaharu; Masuda, Kai; Ohgaki, Hideaki

    2015-10-01

    For detection of hidden special nuclear materials (SNMs), we have developed an active neutron-based interrogation system combined with a D-D fusion pulsed neutron source and a neutron detection system. In the detection scheme, we have adopted new measurement techniques simultaneously; neutron noise analysis and neutron energy spectrum analysis. The validity of neutron noise analysis method has been experimentally studied in the Kyoto University Critical Assembly (KUCA), and was applied to a cargo container inspection system by simulation.

  14. The on-line charge breeding program at TRIUMF's Ion Trap For Atomic and Nuclear Science for precision mass measurements

    SciTech Connect

    Simon, M. C.; Eberhardt, B.; Jang, F.; Luichtl, M.; Robertson, D.; Chaudhuri, A.; Delheij, P.; Grossheim, A.; Kwiatkowski, A. A.; Mane, E.; Pearson, M. R.; Schultz, B. E.; Bale, J. C.; Chowdhury, U.; Ettenauer, S.; Gallant, A. T.; Dilling, J.; Lennarz, A.; Ma, T.; Andreoiu, C.; and others

    2012-02-15

    TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN) constitutes the only high precision mass measurement setup coupled to a rare isotope facility capable of increasing the charge state of short-lived nuclides prior to the actual mass determination in a Penning trap. Recent developments around TITAN's charge breeder, the electron beam ion trap, form the basis for several successful experiments on radioactive isotopes with half-lives as low as 65 ms and in charge states as high as 22+.

  15. Measurements of individual radiation doses in residents living around the Fukushima Nuclear Power Plant.

    PubMed

    Nagataki, Shigenobu; Takamura, Noboru; Kamiya, Kenji; Akashi, Makoto

    2013-11-01

    At the outset of the accident at Fukushima Daiichi Nuclear Power Plant in March 2011, the radiation doses experienced by residents were calculated from the readings at monitoring posts, with several assumptions being made from the point of view of protection and safety. However, health effects should also be estimated by obtaining measurements of the individual radiation doses. The individual external radiation doses, determined by a behavior survey in the "evacuation and deliberate evacuation area" in the first 4 months, were <5 mSv in 97.4% of residents (maximum: 15 mSv). Doses in Fukushima Prefecture were <3 mSv in 99.3% of 386,572 residents analyzed. External doses in Fukushima City determined by personal dosimeters were <1 mSv/3 months (September-November, 2011) in 99.7% of residents (maximum: 2.7 mSv). Thyroid radiation doses, determined in March using a NaI (TI) scintillation survey meter in children in the evacuation and deliberate evacuation area, were <10 mSv in 95.7% of children (maximum: 35 mSv). Therefore, all doses were less than the intervention level of 50 mSv proposed by international organizations. Internal radiation doses determined by cesium-134 ((134)C) and cesium-137 ((137)C) whole-body counters (WBCs) were <1 mSv in 99% of the residents, and the maximum thyroid equivalent dose by iodine-131 WBCs was 20 mSv. The exploratory committee of the Fukushima Health Management Survey mentions on its website that radiation from the accident is unlikely to be a cause of adverse health effects in the future. In any event, sincere scientific efforts must continue to obtain individual radiation doses that are as accurate as possible. However, observation of the health effects of the radiation doses described above will require reevaluation of the protocol used for determining adverse health effects. The dose-response relationship is crucial, and the aim of the survey should be to collect sufficient data to confirm the presence or absence of radiation health

  16. Recent developments at TRISTAN: nuclear structure studies of neutron-rich nuclei

    SciTech Connect

    Gill, R.L.

    1985-01-01

    The nuclear physics program at the fission product mass separator, TRISTAN, has greatly expanded, both in the types of experiments possible and in the range of nuclei available. Surface ionization, FEBIAD, high-temperature thermal, high-temperature plasma, and negative surface ionization ion sources are routinely available. Experimental facilities developed to further expand the capabilities of TRISTAN include a superconducting magnet for g-factor and Q/sub ..beta../ measurements, a windowless Si(Li) detector for conversion electron measurements, and a colinear fast-beam dye laser system for hyperfine interaction studies. This combination of ion sources, experimental apparatus, and the long running time available at a reactor makes TRISTAN a powerful tool for nuclear structure studies of neutron-rich nuclei. The effect of these developments on the nuclear physics program at TRISTAN will be discussed and recent results from some of these facilities will be presented. 6 refs., 3 figs.

  17. Using magnetic moments to study the nuclear structure of I{>=} 2 states

    SciTech Connect

    Torres, D. A.

    2013-05-06

    The experimental study of magnetic moments for nuclear states near the ground state, I{>=} 2, provides a powerful tool to test nuclear structure models. Traditionally, the use of Coulomb excitation reactions have been utilized to study low spin states, mostly I= 2. The use of alternative reaction channels, such as {alpha} transfer, for the production of radioactive species that, otherwise, will be only produced in future radioactive beam facilities has proved to be an alternative to measure not only excited states with I > 2, but to populate and study long-live radioactive nuclei. This contribution will present the experimental tools and challenges for the use of the transient field technique for the measurement of g factors in nuclear states with I{>=} 2, using Coulomb excitation and {alpha}-transfer reactions. Recent examples of experimental results near the N= 50 shell closure, and the experimental challenges for future implementations with radioactive beams, will be discussed.

  18. Response of sheep lymphocytes to PHA: quantitation by nuclear volume measurement and cell counts (40764)

    SciTech Connect

    Chandra, P.; Chanana, A.D.; Joel, D.D.

    1980-03-01

    Phytohemagglutinin response of peripheral blood lymphocytes (PBL) of sheep was studied. Assessment of proliferative response was performed by determination of nuclear volumes and cell counts in cultures from 14 sheep and by incorporation of tritiated thymidine in cultures in four additional sheep. PBL of sheep were found to transform and proliferate with PHA similarly to human peripheral blood lymphocytes with minor differences. Quantitation of the proliferative response by determining the cell count and nuclear volumes provided more information on cell kinetics in culture than the commonly used isotope-labeled thymidine incorporation method.

  19. Measurement of changes in high-energy phosphates in the cardiac cycle using gated 31P nuclear magnetic renonance.

    PubMed Central

    Fossel, E T; Morgan, H E; Ingwall, J S

    1980-01-01

    Levels of the high-energy phosphate-containing compounds, ATP and creatine phosphate, and of inorganic phosphate (Pi) were measured as a function of position in the cardiac cycle. Measurements were made on isolated, perfused, working rat hearts through the use of gated 31P nuclear magnetic resonance spectroscopy. Levels of ATP and creatine phosphate were found to vary during the cardiac cycle and were maximal at minimal aortic pressure and minimal at maximal aortic pressure. Pi varied inversely with the high-energy phosphates. PMID:6932041

  20. Measured Nuclear Recoil Discrimination for HPGS, a Proposed Ton-Scale Dark Matte r Search in Room Temperature Gas

    NASA Astrophysics Data System (ADS)

    Martin, C.; Barton, D.; Dion, M. P.; Esterline, J. H.; Howell, C. R.; Martoff, C. J.; Smith, P. F.; Tornow, W.

    2009-05-01

    The HPGS dark matter proposal is for a simple, room-temperature, ton-scale, 5-10 bar gas scintillation array with nuclear recoil discrimination by pulse-shape, aided by electric fields to suppress wall events. The first experimental confirmation of nuclear recoil discrimination by Xe gas scintillation pulse shape is reported here. Pulse shapes for γ- and x-rays, neutrons, and α particles were measured using highly purified Xe gas at 1-6 bar with a UV-sensitive photomultiplier. Nuclear recoil and α pulses were dominated by recombination scintillation with time constant 250 ns, while gamma and x-ray scintillation was completely contained within 15 ns. We will present detailed comparison of our nuclear recoil pulse shape discrimination to liquid Xe, and discuss the outlook for simpler and lower cost room temperature ton-scale dark matter detectors. (We heartily thank A. Bolotnikov for access to high-purity Xe in his lab at Brookhaven National Laboratory.)

  1. A nonintrusive nuclear monitor for measuring liquid contents in sealed vessels

    NASA Technical Reports Server (NTRS)

    Singh, J. J.; Mall, G. H.

    1984-01-01

    A nonintrusive nuclear technique for monitoring fluid contents in sealed vessels, regardless of the fluid distribution inside the vessels is described. The technique is applicable to all-g environments. It is based on the differences in Cesium-137 gamma ray attenuation coefficients in air and the test liquids.

  2. Helium diffusion coefficient measurements in R7T7 nuclear glass by 3He(d,α) 1H nuclear reaction analysis

    NASA Astrophysics Data System (ADS)

    Chamssedine, F.; Sauvage, T.; Peuget, S.; Fares, T.; Martin, G.

    2010-05-01

    The immobilization of fission products and minor actinides by vitrification is the reference process for industrial management of high-level radioactive wastes generated by spent fuel reprocessing. Radiation damage and radiogenic helium accumulation must be specifically studied to evaluate the effects of minor actinide alpha decay on the glass long-term behavior under repository conditions. A specific experimental study was conducted for a comprehensive evaluation of the behavior of helium and its diffusion mechanisms in borosilicate nuclear waste glass. Helium production was simulated by external implantation with 3He ions at a concentration (≈1 at.%) 30 times higher than obtained after 10,000 years of storage. Helium diffusion coefficients as a function of temperature were extracted from the depth profiles after annealing. The 3He(d,α) 1H nuclear reaction analysis (NRA) technique was successfully adopted for low-temperature in situ measurements of depth profiles. Its high depth resolution revealed helium mobility at temperatures as low as 253 K and the presence of a trapped helium fraction. The diffusion coefficients of un-trapped helium atoms follow an Arrhenius law between 253 K and 323 K. An activation energy of 0.55 ± 0.03 eV was determined, which is consistent with a process controlled by diffusion in the glass free volume.

  3. Neutron measurements in the Vandellòs II nuclear power plant with a Bonner sphere system.

    PubMed

    Fernández, F; Bakali, M; Tomás, M; Muller, H; Pochat, J L

    2004-01-01

    In some Spanish nuclear power plants of pressurised water reactor (PWR) type, albedo thermoluminescence dosemeters are used for personal dosimetry while survey meters, based on a thermal-neutron detector inside a cylindrical or spherical moderator, are used for dose rate assessment in routine monitoring. The response of both systems is highly dependent on the energy of the existing neutron fields. They are usually calibrated by means of ISO neutron sources with energy distributions quite different from those encountered at these installations. Spectrometric measurements with a Bonner sphere system (BSS) allow us to determine the reference dosimetric values. The UAB group, under request from the National Coordinated Research Action, was in charge of characterising the neutron fields and evaluating the response of personal dosemeters at several measurement points inside the containment building of the Catalan Nuclear Power Plant Vandellòs II. The neutron fields were characterised at five places using the UAB-BSS and a home made unfolding code called MITOM. The results obtained confirm the presence of low-energy components in the neutron field in most of the selected points. Moreover, we have found no influence of the nuclear fuel burning on the shape of the spectrum. PMID:15353701

  4. Measurements and Observations of 134Cs and 137Cs around a Nuclear Power Plant in Busan, South Korea

    NASA Astrophysics Data System (ADS)

    Chong, H. Y.; Park, J. N.; Kim, J. S.

    2015-12-01

    The purpose of this study is to know the change of representative species 134Cs and 137Cs of artificial radionuclides from the nuclear power station nearby for the last five years(2010~2014). The Kori Nuclear Power Plant, nuclear power facility located near Busan, is located in the south-east coast of Korea and about 21km north-east away from the Haeundae and about 25km south away from the Ulsan. An administrative district is Jangan-eup, Gijang-gun, Busan, Korea. A point was selected on the basis of the "Environmental Radiation Monitoring Plan around Nuclear Power Plants" and periodically samples were collected and analyzed. The samples were collected from the soils of the surface in the Wolnae area (NW, 1.7km). The soil samples were analyzed by gamma spectrometer with High Purity Germanium detector (HPGe) of 40% relative efficiency and were measured for 80,000 sec. As a results of soil analysis, 137Cs were detected in samples only selected in March 2013. The activity concentration of 137Cs founded in the soil sample was 0.513±0.052Bq/kg-dry. In the other hands, the concentration of 137Cs in the year 2010, 2011, 2012, and 2014 were below the minimum detectable activity (MDA). 40K, natural radionuclides which is widely present, was detected in the soil samples and other artificial radionuclides were not detected. The result of overall comparison of the environmental radioactivity survey around Kori Nuclear Power Plant for the last five years is that radioactivity levels are within average range. However, it is necessary to continue to carefully observe a fine change in regional or the monthly radiation concentration.

  5. A simple double quantum coherence ESR sequence that minimizes nuclear modulations in Cu2+-ion based distance measurements

    NASA Astrophysics Data System (ADS)

    Ruthstein, Sharon; Ji, Ming; Shin, Byong-kyu; Saxena, Sunil

    2015-08-01

    Double quantum coherence (DQC) ESR is a sensitive method to measure magnetic dipolar interactions between spin labels. However, the DQC experiment on Cu2+ centers presents a challenge at X-band. The Cu2+ centers are usually coordinated to histidine residues in proteins. The electron-nuclear interaction between the Cu2+ ion and the remote nitrogen in the imidazole ring can interfere with the electron-electron dipolar interaction. Herein, we report on a modified DQC experiment that has the advantage of reduced contributions from electron-nuclear interactions, which enhances the resolution of the DQC signal to the electron-electron dipolar modulations. The modified pulse-sequence is verified on Cu2+-NO system in a polyalanine-based peptide and on a coupled Cu2+ system in a polyproline-based peptide. The modified DQC data were compared with the DEER data and good agreement was found.

  6. Direct observation of an isomeric state in 98Rb and nuclear properties of exotic rubidium isotopes measured by laser spectroscopy

    NASA Astrophysics Data System (ADS)

    Procter, T. J.; Behr, J. A.; Billowes, J.; Buchinger, F.; Cheal, B.; Crawford, J. E.; Dilling, J.; Garnsworthy, A. B.; Leary, A.; Levy, C. D. P.; Mané, E.; Pearson, M. R.; Shelbaya, O.; Stolz, M.; Al Tamimi, W.; Voss, A.

    2015-02-01

    Fast-beam collinear laser spectroscopy experiments on rubidium have been performed at the ISAC radioactive ion beam facility at TRIUMF. Most recently, the neutron-rich 98Rb isotope has been studied for the investigation of shape coexistence. Two long-lived nuclear states in 98Rb have been clearly observed for the first time: a low-spin state, assigned a spin of I = 0, and a high-spin state. The high-spin state is tentatively assigned a spin of I = 3 based on this analysis in combination with gamma decay results. The measured nuclear properties of the two states are presented, alongside unpublished values of the neutron-deficient isotopes investigated previously. The mean-square charge radii of both states in 98Rb are observed to continue along the isodeformation line present after the N = 60 onset of deformation.

  7. Recent Improvement of Measurement Instrumentation to Supervise Nuclear Operations and to Contribute Input Data to 3D Simulation Code - 13289

    SciTech Connect

    Mahe, Charly; Chabal, Caroline

    2013-07-01

    The CEA has developed many compact characterization tools to follow sensitive operations in a nuclear environment. Usually, these devices are made to carry out radiological inventories, to prepare nuclear interventions or to supervise some special operations. These in situ measurement techniques mainly take place at different stages of clean-up operations and decommissioning projects, but they are also in use to supervise sensitive operations when the nuclear plant is still operating. In addition to this, such tools are often associated with robots to access very highly radioactive areas, and thus can be used in accident situations. Last but not least, the radiological data collected can be entered in 3D calculation codes used to simulate the doses absorbed by workers in real time during operations in a nuclear environment. Faced with these ever-greater needs, nuclear measurement instrumentation always has to involve on-going improvement processes. Firstly, this paper will describe the latest developments and results obtained in both gamma and alpha imaging techniques. The gamma camera has been used by the CEA since the 1990's and several changes have made this device more sensitive, more compact and more competitive for nuclear plant operations. It is used to quickly identify hot spots, locating irradiating sources from 50 keV to 1500 keV. Several examples from a wide field of applications will be presented, together with the very latest developments. The alpha camera is a new camera used to see invisible alpha contamination on several kinds of surfaces. The latest results obtained allow real time supervision of a glove box cleaning operation (for {sup 241}Am contamination). The detection principle as well as the main trials and results obtained will be presented. Secondly, this paper will focus on in situ gamma spectrometry methods developed by the CEA with compact gamma spectrometry probes (CdZnTe, LaBr{sub 3}, NaI, etc.). The radiological data collected is used

  8. Measures of the Environmental Footprint of the Front End of the Nuclear Fuel Cycle

    SciTech Connect

    Brett Carlsen; Emily Tavrides; Erich Schneider

    2010-08-01

    Previous estimates of environmental impacts associated with the front end of the nuclear fuel cycle have focused primarily on energy consumption and CO2 emissions. Results have varied widely. Section 2 of this report provides a summary of historical estimates. This study revises existing empirical correlations and their underlying assumptions to fit to a more complete set of existing data. This study also addresses land transformation, water withdrawals, and occupational and public health impacts associated with the processes of the front end of the once-through nuclear fuel cycle. These processes include uranium mining, milling, refining, conversion, enrichment, and fuel fabrication. Metrics are developed to allow environmental impacts to be summed across the full set of front end processes, including transportation and disposition of the resulting depleted uranium.

  9. A new fast scanning system for the measurement of large angle tracks in nuclear emulsions

    NASA Astrophysics Data System (ADS)

    Alexandrov, A.; Buonaura, A.; Consiglio, L.; D'Ambrosio, N.; De Lellis, G.; Di Crescenzo, A.; Di Marco, N.; Galati, G.; Lauria, A.; Montesi, M. C.; Pupilli, F.; Shchedrina, T.; Tioukov, V.; Vladymyrov, M.

    2015-11-01

    Nuclear emulsions have been widely used in particle physics to identify new particles through the observation of their decays thanks to their unique spatial resolution. Nevertheless, before the advent of automatic scanning systems, the emulsion analysis was very demanding in terms of well trained manpower. Due to this reason, they were gradually replaced by electronic detectors, until the '90s, when automatic microscopes started to be developed in Japan and in Europe. Automatic scanning was essential to conceive large scale emulsion-based neutrino experiments like CHORUS, DONUT and OPERA. Standard scanning systems have been initially designed to recognize tracks within a limited angular acceptance (θ lesssim 30°) where θ is the track angle with respect to a line perpendicular to the emulsion plane. In this paper we describe the implementation of a novel fast automatic scanning system aimed at extending the track recognition to the full angular range and improving the present scanning speed. Indeed, nuclear emulsions do not have any intrinsic limit to detect particle direction. Such improvement opens new perspectives to use nuclear emulsions in several fields in addition to large scale neutrino experiments, like muon radiography, medical applications and dark matter directional detection.

  10. Measurement of the 19F(α,n)22Na Cross Section for Nuclear Safeguards Science

    NASA Astrophysics Data System (ADS)

    Lowe, Marcus; Smith, M. S.; Pain, S.; Febbraro, M.; Pittman, S.; Chipps, K. A.; Thompson, S. J.; Grinder, M.; Grzywacz, R.; Smith, K.; Thornsberry, C.; Thompson, P.; Peters, W. A.; Waddell, D.; Blanchard, R.; Carls, A.; Shadrick, S.; Engelhardt, A.; Hertz-Kintish, D.; Allen, N.; Sims, H.

    2015-10-01

    Enriched uranium is commonly stored in fluoride matrices such as UF6. Alpha decays of uranium in UF6 will create neutrons via the 19F(α,n)22Na reaction. An improved cross section for this reaction will enable improved nondestructive assays of uranium content in storage cylinders at material enrichment facilities. To determine this reaction cross section, we have performed experiments using both forward and inverse kinematic techniques at the University of Notre Dame (forward) and Oak Ridge National Laboratory (inverse). Both experiments utilized the Versatile Array of Neutron Detectors at Low Energy (VANDLE) for neutron detection. The ORNL experiment also used a new ionization chamber for 22Na particle identification. Gating on the 22Na nuclei detected drastically reduced the background counts in the neutron time-of-flight spectra. The latest analysis and results will be presented for 19F beam energies ranging from 20-37 MeV. This work is funded in part by the DOE Office of Nuclear Physics, the National Nuclear Security Administration's Office of Defense Nuclear Nonproliferation R&D, and the NSF.

  11. J/{Psi} production in nuclear collisions: Theoretical approach to measuring the transport coefficient

    SciTech Connect

    Kopeliovich, B. Z.; Potashnikova, I. K.; Schmidt, Ivan

    2010-08-15

    The observed p{sub T} dependence of nuclear effects for J/{Psi} produced in heavy-ion collisions at Brookhaven's Relativistic Heavy-Ion Collider (RHIC) might look puzzling, because the nuclear suppression seems to fade at large p{sub T}. We explain this by the interplay of three mechanisms: (i) attenuation of J/{Psi} in the hot medium created in the nuclear collision; (ii) initial-state shadowing of charmed quarks and attenuation of a c-barc dipole propagating through the colliding nuclei; (iii) a strong Cronin effect for J/{Psi} caused by saturation of gluons in the colliding nuclei. All three effects are well under control and calculated in a parameter-free way, except for the transport coefficient q{sub 0} characterizing the medium. This is adjusted to the J/{Psi} data and found to be in good agreement with the pQCD prediction, but more than an order of magnitude smaller than what was extracted from jet quenching data within the energy loss scenario.

  12. The molecular mechanism of nuclear transport revealed by atomic-scale measurements

    PubMed Central

    Hough, Loren E; Dutta, Kaushik; Sparks, Samuel; Temel, Deniz B; Kamal, Alia; Tetenbaum-Novatt, Jaclyn; Rout, Michael P; Cowburn, David

    2015-01-01

    Nuclear pore complexes (NPCs) form a selective filter that allows the rapid passage of transport factors (TFs) and their cargoes across the nuclear envelope, while blocking the passage of other macromolecules. Intrinsically disordered proteins (IDPs) containing phenylalanyl-glycyl (FG)-rich repeats line the pore and interact with TFs. However, the reason that transport can be both fast and specific remains undetermined, through lack of atomic-scale information on the behavior of FGs and their interaction with TFs. We used nuclear magnetic resonance spectroscopy to address these issues. We show that FG repeats are highly dynamic IDPs, stabilized by the cellular environment. Fast transport of TFs is supported because the rapid motion of FG motifs allows them to exchange on and off TFs extremely quickly through transient interactions. Because TFs uniquely carry multiple pockets for FG repeats, only they can form the many frequent interactions needed for specific passage between FG repeats to cross the NPC. DOI: http://dx.doi.org/10.7554/eLife.10027.001 PMID:26371551

  13. A New Contribution for WYP 2005: The Golden Ratio, Bohr Radius, Planck's Constant, Fine-Structure Constant and g-Factors

    NASA Astrophysics Data System (ADS)

    Heyrovska, R.; Narayan, S.

    2005-10-01

    Recently, the ground state Bohr radius (aB) of hydrogen was shown to be divided into two Golden sections, aB,p = aB/ø2 and aB,e = aB/ø at the point of electrical neutrality, where ø = 1.618 is the Golden ratio (R. Heyrovska, Molecular Physics 103: 877-882, and the literature cited therein). The origin of the difference of two energy terms in the Rydberg equation was thus shown to be in the ground state energy itself, as shown below: EH = (1/2)e2/(κaB) = (1/2)(e2/κ) [(1/aB,p - (1/aB,e)] (1). This work brings some new results that 1) a unit charge in vacuum has a magnetic moment, 2) (e2/2κ) in eq. (1) is an electromagnetic condenser constant, 3) the de Broglie wavelengths of the proton and electron correspond to the Golden arcs of a circle with the Bohr radius, 4) the fine structure constant (α) is the ratio of the Planck's constants without and with the interaction of light with matter, 5) the g-factors of the electron and proton, ge/2 and gp/2 divide the Bohr radius at the magnetic center and 6) the ``mysterious'' value (137.036) of α -1 = (360/ø2) - (2/ø3), where (2/ø3) arises from the difference, (gp - ge).

  14. Enhanced anisotropic effective g factors of an Al0.25Ga0.75N/GaN heterostructure based quantum point contact.

    PubMed

    Lu, Fangchao; Tang, Ning; Huang, Shaoyun; Larsson, Marcus; Maximov, Ivan; Graczyk, Mariusz; Duan, Junxi; Liu, Sidong; Ge, Weikun; Xu, Fujun; Shen, Bo

    2013-10-01

    Gate-defined quantum point contacts (QPCs) were fabricated with Al0.25Ga0.75N/GaN heterostructures grown by metal-organic chemical vapor deposition (MOCVD). In the transport study of the Zeeman effect, greatly enhanced effective g factors (g*) were obtained. The in-plane g* is found to be 5.5 ± 0.6, 4.8 ± 0.4, and 4.2 ± 0.4 for the first to the third subband, respectively. Similarly, the out-of-plane g* is 8.3 ± 0.6, 6.7 ± 0.7, and 5.1 ± 0.7. Increasing g* with the population of odd-numbered spin-splitted subbands are obtained at 14 T. This portion of increase is assumed to arise from the exchange interaction in one-dimensional systems. A careful analysis shows that not only the exchange interaction but the spin-orbit interaction (SOI) in the strongly confined QPC contributes to the enhancement and anisotropy of g* in different subbands. An approach to distinguish the respective contributions from the SOI and exchange interaction is therefore proposed. PMID:24041238

  15. Application of Solid State Nuclear Track Detectors in TEXTOR Experiment for Measurements of Fusion-Reaction Protons

    SciTech Connect

    Szydlowski, A.; Malinowska, A.; Jaskola, M.; Korman, A.; Sadowski, M. J.; Wassenhove, G. van; Galkowski, A.

    2008-03-19

    The paper reports on measurements of the space distribution of fusion protons of energy equal to about 3-MeV, originating from the D(d, p)T reactions. The measurements were carried out on the TEXTOR facility by means of a small ion pinhole camera, which was equipped with a solid-state nuclear track detector of the PM-355 type. The results obtained in two series of successive discharges are compared. The first series was performed with an additional heating of TEXTOR plasmas with NBI of fast deuterons, whereas in the second series plasma was heated by ICRF and NBI of hydrogen neutrals. Computer simulations of different trajectories of charged particles have been performed with the Gourdon code and the detection efficiency has been calculated for various orientations of the measuring assembly.

  16. Review of geochemical measurement techniques for a nuclear waste repository in bedded salt

    SciTech Connect

    Knauss, K.G.; Steinborn, T.L.

    1980-05-22

    A broad, general review is presented of geochemical measurement techniques that can provide data necessary for site selection and repository effectiveness assessment for a radioactive waste repository in bedded salt. The available measurement techniques are organized according to the parameter measured. The list of geochemical parameters include all those measurable geochemical properties of a sample whole values determine the geochemical characteristics or behavior of the system. For each technique, remarks are made pertaining to the operating principles of the measurement instrument and the purpose for which the technique is used. Attention is drawn to areas where further research and development are needed.

  17. Measuring radioactive noble gases by absorption in polycarbonates and other organics: From radon indoors to nuclear safety

    NASA Astrophysics Data System (ADS)

    Pressyanov, Dobromir S.

    2013-07-01

    The report summarizes recent research and practice of using materials with high absorption ability to noble gases to measure their radioactive isotopes. Most of the studies employ bisphenol-A based polycarbonates, because of their remarkably high absorption ability to noble gases. This is the material of which commercial CDs/DVDs are made and they may serve as serendipitous, already available in dwellings, radon and thoron detectors. We present the essence of the gathered experimental evidence that the CD/DVD method can successfully address some long-lasted problems in radon dosimetry: The first is making sufficiently precise retrospective 222Rn dosimetry for the purposes of epidemiological studies and risk estimation. The second is rapid identification of buildings with radon problem. We demonstrate how this can be used to develop an integrated approach to the radon problem. Within this approach detection, diagnostic and mitigation are considered as an unified whole, and the interval between the decision to provide disks for analysis and the complete mitigation of the building, if radon problem is identified, is short. Besides radon and thoron, bisphenol-A based polycarbonates were successfully used to measure 85Kr and 133Xe for the purposes of the effluents control and nuclear safety of nuclear installations. The perspectives to employ other organic materials in which noble gases are highly soluble for measurement of their radioactive isotopes are also discussed.

  18. On the combination of delayed neutron and delayed gamma techniques for fission rate measurement in nuclear fuel

    SciTech Connect

    Perret, G.; Jordan, K. A.

    2011-07-01

    Novel techniques to measure newly induced fissions in spent fuel after re-irradiation at low power have been developed and tested at the Proteus zero-power research reactor. The two techniques are based on the detection of high energy gamma-rays emitted by short-lived fission products and delayed neutrons. The two techniques relate the measured signals to the total fission rate, the isotopic composition of the fuel, and nuclear data. They can be combined to derive better estimates on each of these parameters. This has potential for improvement in many areas. Spent fuel characterisation and safeguard applications can benefit from these techniques for non-destructive assay of plutonium content. Another application of choice is the reduction of uncertainties on nuclear data. As a first application of the combination of the delayed neutron and gamma measurement techniques, this paper shows how to reduce the uncertainties on the relative abundances of the longest delayed neutron group for thermal fissions in {sup 235}U, {sup 239}Pu and fast fissions in {sup 238}U. The proposed experiments are easily achievable in zero-power research reactors using fresh UO{sub 2} and MOX fuel and do not require fast extraction systems. The relative uncertainties (1{sigma}) on the relative abundances are expected to be reduced from 13% to 4%, 16% to 5%, and 38% to 12% for {sup 235}U, {sup 238}U and {sup 239}Pu, respectively. (authors)

  19. [Radiation measures and trend after the Fukushima Daiichi Nuclear Power Plant accident].

    PubMed

    Okazaki, Ryuji

    2014-02-01

    The radioactive materials spread by the Fukushima Daiichi Nuclear Power Plant (NPP) accident in March, 2011 caused NPP workers to be exposed to radiation above ordinance limits. The number of workers exposed to radiation within ordinance limits is increasing. Decontamination began at many places in Fukushima, although new laws were enforced in the decontamination work, in the current situation, medical examinations for radiation are limited due to a shortage of doctors. In this paper, I introduce the ordinances on the prevention of ionizing radiation hazards and the revised points about radiation exposure doses of the NPP workers, as well as the new ordinance for decontamination. PMID:24605520

  20. Evolution of nuclear ground-state properties of neutron-deficient isotopes around Z =82 from precision mass measurements

    NASA Astrophysics Data System (ADS)

    Böhm, Ch.; Borgmann, Ch.; Audi, G.; Beck, D.; Blaum, K.; Breitenfeldt, M.; Cakirli, R. B.; Cocolios, T. E.; Eliseev, S.; George, S.; Herfurth, F.; Herlert, A.; Kowalska, M.; Kreim, S.; Lunney, D.; Manea, V.; Minaya Ramirez, E.; Naimi, S.; Neidherr, D.; Rosenbusch, M.; Schweikhard, L.; Stanja, J.; Wang, M.; Wolf, R. N.; Zuber, K.

    2014-10-01

    High-precision mass measurements of neutron-deficient Tl (A =184, 186, 190, 193-195, 198) isotopes as well as Pb (A =202,208), Fr (A =207,208), and Ra (A =224) are performed with the Penning-trap mass spectrometer ISOLTRAP at ISOLDE/CERN. The improved precision of the mass data now allows the study of subtle odd-even effects. The gradual development of collectivity with the removal of protons from the magic Z =82 core is analyzed by combining the new mass results with nuclear charge-radii data and mean-field model predictions.

  1. Evaluation of hybrid algorithm for analysis of scattered light using ex vivo nuclear morphology measurements of cervical epithelium.

    PubMed

    Ho, Derek; Drake, Tyler K; Bentley, Rex C; Valea, Fidel A; Wax, Adam

    2015-08-01

    We evaluate a new hybrid algorithm for determining nuclear morphology using angle-resolved low coherence interferometry (a/LCI) measurements in ex vivo cervical tissue. The algorithm combines Mie theory based and continuous wavelet transform inverse light scattering analysis. The hybrid algorithm was validated and compared to traditional Mie theory based analysis using an ex vivo tissue data set. The hybrid algorithm achieved 100% agreement with pathology in distinguishing dysplastic and non-dysplastic biopsy sites in the pilot study. Significantly, the new algorithm performed over four times faster than traditional Mie theory based analysis. PMID:26309741

  2. Analysis of Round Robin Test for Ultrasonic Thickness Measurement of Wall Thinned Pipe in Nuclear Power Plant

    NASA Astrophysics Data System (ADS)

    Lee, Dae-Hoon; Lee, Seung-Joon; Lee, Joon-Hyun; Lee, Sung-Ho

    2008-02-01

    It is well recognized that one of the most serious problems on the maintenance of piping system in Nuclear Power Plants (NPPs) is the wall thinning of carbon steel pipe components. The objective of this research is to verify confidence of wall thinning measurement system by conducting Round Robin Test (RRT). 23 specimens with different size and shape of pipe were used according to standard practice in RRT. The gage R&R analysis was introduced for each sigma quality level, so that repeatability and reproducibility can be estimated from RRT results.

  3. Measurement of partonic nuclear effects in deep-inelastic neutrino scattering using MINERvA

    DOE PAGESBeta

    Mousseau, J.

    2016-04-19

    Here, the MINERvA Collaboration reports a novel study of neutrino-nucleus charged-current deep inelastic scattering (DIS) using the same neutrino beam incident on targets of polystyrene, graphite, iron, and lead. Results are presented as ratios of C, Fe, and Pb to CH. The ratios of total DIS cross sections as a function of neutrino energy and flux-integrated differential cross sections as a function of the Bjorken scaling variable x are presented in the neutrino-energy range of 5–50 GeV. Based on the predictions of charged-lepton scattering ratios, good agreement is found between the data and prediction at medium x and low neutrino energy.more » However, the ratios appear to be below predictions in the vicinity of the nuclear shadowing region, x < 0.1. This apparent deficit, reflected in the DIS cross-section ratio at high Eν, is consistent with previous MINERvA observations [B. Tice (MINERvA Collaboration), Phys. Rev. Lett. 112, 231801 (2014).] and with the predicted onset of nuclear shadowing with the axial-vector current in neutrino scattering.« less

  4. Measurement of partonic nuclear effects in deep-inelastic neutrino scattering using MINERvA

    NASA Astrophysics Data System (ADS)

    Mousseau, J.; Wospakrik, M.; Aliaga, L.; Altinok, O.; Bellantoni, L.; Bercellie, A.; Betancourt, M.; Bodek, A.; Bravar, A.; Budd, H.; Cai, T.; Carneiro, M. F.; Christy, M. E.; Chvojka, J.; da Motta, H.; Devan, J.; Dytman, S. A.; Díaz, G. A.; Eberly, B.; Felix, J.; Fields, L.; Fine, R.; Gago, A. M.; Galindo, R.; Gallagher, H.; Ghosh, A.; Golan, T.; Gran, R.; Harris, D. A.; Higuera, A.; Hurtado, K.; Kiveni, M.; Kleykamp, J.; Kordosky, M.; Le, T.; Maher, E.; Manly, S.; Mann, W. A.; Marshall, C. M.; Martinez Caicedo, D. A.; McFarland, K. S.; McGivern, C. L.; McGowan, A. M.; Messerly, B.; Miller, J.; Mislivec, A.; Morfín, J. G.; Naples, D.; Nelson, J. K.; Norrick, A.; Nuruzzaman; Osta, J.; Paolone, V.; Park, J.; Patrick, C. E.; Perdue, G. N.; Rakotondravohitra, L.; Ramirez, M. A.; Ransome, R. D.; Ray, H.; Ren, L.; Rimal, D.; Rodrigues, P. A.; Ruterbories, D.; Schellman, H.; Schmitz, D. W.; Solano Salinas, C. J.; Tagg, N.; Tice, B. G.; Valencia, E.; Walton, T.; Wolcott, J.; Zavala, G.; Zhang, D.; Minerν A Collaboration

    2016-04-01

    The MINERvA Collaboration reports a novel study of neutrino-nucleus charged-current deep inelastic scattering (DIS) using the same neutrino beam incident on targets of polystyrene, graphite, iron, and lead. Results are presented as ratios of C, Fe, and Pb to CH. The ratios of total DIS cross sections as a function of neutrino energy and flux-integrated differential cross sections as a function of the Bjorken scaling variable x are presented in the neutrino-energy range of 5-50 GeV. Based on the predictions of charged-lepton scattering ratios, good agreement is found between the data and prediction at medium x and low neutrino energy. However, the ratios appear to be below predictions in the vicinity of the nuclear shadowing region, x <0.1 . This apparent deficit, reflected in the DIS cross-section ratio at high Eν, is consistent with previous MINERvA observations [B. Tice et al. (MINERvA Collaboration), Phys. Rev. Lett. 112, 231801 (2014).] and with the predicted onset of nuclear shadowing with the axial-vector current in neutrino scattering.

  5. Spectroscopic and physicochemical measurements for on-line monitoring of used nuclear fuel separation processes

    SciTech Connect

    Nee, Ko; Nilsson, M.; Bryan, S.; Levitskaia, T.

    2013-07-01

    Separation processes for used nuclear fuel are often complicated and challenging due to the high constraints in purity of the products and safeguards of the process streams. In order to achieve a safe, secure and efficient separation process, the liquid streams in the separation process require close monitoring. Due to the high radiation environment, sampling of the materials is difficult. Availability of a detection technique that is remote, non-destructive and can avoid time-delay caused by retrieving samples would be beneficial and could minimize the exposure to personnel and provide material accountancy to avoid diversion (non-proliferation). For example, Ultra Violet (UV), Visible (Vis), Near-Infrared (NIR) and Raman spectroscopy that detect and quantify elements present in used nuclear fuel, e.g. lanthanides, actinides and molecules such as nitrate, can be used. In this work, we have carried out NIR and Raman spectroscopy to study aqueous solutions composed of different concentrations of nitric acid, sodium nitrate, and neodymium at varied temperatures. A chemometric model for online monitoring based on the PLS-Toolbox (MATLAB) software has been developed and validated to provide chemical composition of process streams based on spectroscopic data. In conclusion, both of our NIR and Raman spectra were useful for H{sup +} and NO{sub 3} prediction, and only NIR was helpful for the Nd{sup 3+} prediction.

  6. CDMS detector fabrication improvements and low energy nuclear recoil measurements in germanium

    NASA Astrophysics Data System (ADS)

    Jastram, Andrew Karl

    As the CDMS (Cryogenic Dark Matter Search) experiment is scaled up to tackle new dark matter parameter spaces (lower masses and cross-sections), detector production efficiency and repeatability becomes ever more important. A dedicated facility has been commissioned for SuperCDMS detector fabrication at Texas A&M University (TAMU). The fabrication process has been carefully tuned using this facility and its equipment. Production of successfully tested detectors has been demonstrated. Significant improvements in detector performance have been made using new fabrication methods, equipment, and tuning of process parameters. This work has demonstrated the capability for production of next generation CDMS SNOLAB detectors. Additionally, as the dark matter parameter space is probed further, careful calibrations of detector response to nuclear recoil interactions must be performed in order to extract useful information (in relation to dark matter particle characterizations) from experimental results. A neutron beam of tunable energy is used in conjunction with a commercial radiation detector to characterize ionization energy losses in germanium during nuclear recoil events. Data indicates agreement with values predicted by the Lindhard equation, providing a best-fit k-value of 0.146.

  7. [Measurement of left atrial and ventricular volumes in real-time 3D echocardiography. Validation by nuclear magnetic resonance

    NASA Technical Reports Server (NTRS)

    Bauer, F.; Shiota, T.; Qin, J. X.; White, R. D.; Thomas, J. D.

    2001-01-01

    The measurement of the left ventricular ejection fraction is important for the evaluation of cardiomyopathy and depends on the measurement of left ventricular volumes. There are no existing conventional echocardiographic means of measuring the true left atrial and ventricular volumes without mathematical approximations. The aim of this study was to test anew real time 3-dimensional echocardiographic system of calculating left atrial and ventricular volumes in 40 patients after in vitro validation. The volumes of the left atrium and ventricle acquired from real time 3-D echocardiography in the apical view, were calculated in 7 sections parallel to the surface of the probe and compared with atrial (10 patients) and ventricular (30 patients) volumes calculated by nuclear magnetic resonance with the simpson method and with volumes of water in balloons placed in a cistern. Linear regression analysis showed an excellent correlation between the real volume of water in the balloons and volumes given in real time 3-dimensional echocardiography (y = 0.94x + 5.5, r = 0.99, p < 0.001, D = -10 +/- 4.5 ml). A good correlation was observed between real time 3-dimensional echocardiography and nuclear magnetic resonance for the measurement of left atrial and ventricular volumes (y = 0.95x - 10, r = 0.91, p < 0.001, D = -14.8 +/- 19.5 ml and y = 0.87x + 10, r = 0.98, P < 0.001, D = -8.3 +/- 18.7 ml, respectively. The authors conclude that real time three-dimensional echocardiography allows accurate measurement of left heart volumes underlying the clinical potential of this new 3-D method.

  8. Nuclear astrophysics from neutron cross-section measurements on radiactive samples

    SciTech Connect

    Koehler, P.E.; O'Brien, H.A.

    1988-01-01

    Reaction rates for both big-bang and stellar nucleosynthesis calculations can be obtained from the measurement of (n,p) (n, ..cap alpha..) and (n,..gamma..) cross sections for radioactive nuclei. In the past, large backgrounds associated with the sample activity limited these types of measurements to radioisotopes with very long half lives. The advent of the high-intensity neutron source at the Los Alamos Neutron Scattering CEnter (LANSCE) has greatly increased the number of nuclei which can be studied. Results of recent measurements on samples with half lives as short as fifty-three days are given. Plans for future measurements are discussed. 32 refs., 3 figs.

  9. C++ OPPS, a new software for the interpretation of protein dynamics from nuclear magnetic resonance measurements

    NASA Astrophysics Data System (ADS)

    Zerbetto, Mirco; Polimeno, Antonino; Meirovitch, Eva

    Nuclear magnetic resonance (NMR) is a powerful tool for elucidating protein dynamics because of the possibility to interpret nuclear spin relaxation properties in terms of microdynamic parameters. Magnetic relaxation times T1, T2, and NOE depend on dipolar and quadrupolar interactions, on chemical shift anisotropy and cross-correlation effects. Within the framework of given motional model, it is possible to express the NMR relaxation times as functions of spectral densities (Abragam, The Principles of Nuclear Magnetism; Oxford University Press: Clarendon, London, 1961), obtaining the connection between macroscopic observables and microscopic properties. In this context, recently Meirovitch et al. (Shapiro et al., Biochemistry 2002, 41, 6271, Meirovitch et al., J Phys Chem B 2006, 110, 20615, Meirovitch et al., J Phys Chem B 2007, 111, 12865) applied the dynamical model introduced by Polimeno and Freed (Polimeno and Freed, Adv Chem Phys 1993, 83, 89, Polimeno and Freed, J Phys Chem 1995, 99, 10995), known as the slowly relaxing local structure (SRLS) model, to the study of NMR data. The program C++OPPS (http://www.chimica.unipd.it/licc/), developed in our laboratory, implements the SRLS model in an user-friendly way with a graphical user interface (GUI), introduced to simplify the work to users who do not feel at ease with the complex mathematics of the model and the difficulties of command line based programs. The program is an evolution of the old FORTRAN 77 implementation COPPS (COupled Protein Probe Smoluchowski) and presents a number of new features: the presence of an easy to use GUI written in JAVA; high calculation performance thanks to features of C++ language, employment of BLAS (basic linear algebra subprograms) library (Blackford et al., Trans Math Soft 2002, 28, 135) in handling matrix-vector operations and parallelization of the code under the MPI (message passing interface) paradigm (Gropp et al., Parallel Comput 1996, 22, 789, Gropp and Lusk, User

  10. Comparison of (90)Y activity measurements in nuclear medicine in Germany.

    PubMed

    Kossert, Karsten; Bokeloh, Karen; Ehlers, Marion; Nähle, Ole; Scheibe, Olaf; Schwarz, Uwe; Thieme, Klaus

    2016-03-01

    In 2014, PTB and the company Eckert & Ziegler organized a national comparison exercise to determine the activity of a (90)Y solution. One aim of the comparison was to assess the measurement capability of hospitals and medical practices in Germany. P6-type vials were filled with aliquots of a radioactive (90)Y solution and then sent to 19 participants who were asked to measure the activity in the ampoules as well as in their own standard geometry using syringes. Most of the submitted results have a deviation of less than ±10% from the PTB reference activity when measured in the P6-type vials. The spread is somewhat larger when measured in a syringe geometry. The comparison revealed that some participants have difficulties in applying decay corrections and only a few participants were capable of estimating realistic measurement uncertainties. PMID:26597654

  11. Flux measurements in a nuclear research reactor by using an aluminum nitride detector

    NASA Astrophysics Data System (ADS)

    Moon, B. S.; Yoo, D. S.; Hwang, I. K.; Chung, C. E.; Holcomb, D. E.

    2007-08-01

    A small polycrystalline aluminium nitride detector with a thickness of 381 μm was used to measure a 200,000 Ci Co 60 source and to measure the flux in a research reactor where the neutron flux is about 10 14/cm 2 s, which is nearly the same order as in the commercial power plant. If the applied voltage is greater than or equal to 2000 V and if the measurements are done in a short period of time so that the heat energy does not build up in the aluminium nitride, then the measured electric current is linearly proportional to the input flux. It is assumed of course that the energy spectrum of the input flux remains constant. This linearity relation is illustrated by the results of a measurement in which the reactor power has been controlled so that the flux becomes a step function.

  12. Measurement of the nucleon structure function F2 in the nuclear medium and evaluation of its moments

    DOE PAGESBeta

    Osipenko, M.

    2010-06-01

    We report on the measurement of inclusive electron scattering off a carbon target performed with CLAS at Jefferson Laboratory. A combination of three different beam energies 1.161, 2.261 and 4.461 GeV allowed us to reach an invariant mass of the final-state hadronic system W ≈ 2.4 GeV with four-momentum transfers Q2 ranging from 0.2 to 5 GeV2. These data, together with previous measurements of the inclusive electron scattering off proton and deuteron, which cover a similar continuous two-dimensional region of Q2 and Bjorken variable x, permit the study of nuclear modifications of the nucleon structure. By using these, as wellmore » as other world data, we evaluated the F2 structure function and its moments. Using an OPE-based twist expansion, we studied the Q2-evolution of the moments, obtaining a separation of the leading-twist and the total higher-twist terms. The carbon-to-deuteron ratio of the leading-twist contributions to the F2 moments exhibits the well known EMC effect, compatible with that discovered previously in x-space. The total higher-twist term in the carbon nucleus appears, although with large systematic uncertainites, to be smaller with respect to the deuteron case for n < 7, suggesting partial parton deconfinement in nuclear matter. Lastly, we speculate that the spatial extension of the nucleon is changed when it is immersed in the nuclear medium.« less

  13. Impact of an external radiation field on handheld XRF measurements for nuclear forensics applications

    SciTech Connect

    Steeb, Jennifer L.; Mertz, Carol J.; Finck, Martha R.; Engelstad, Gary; Carney, Kevin P.; Chamberlain, David B.

    2015-03-28

    X-ray fluorescence (XRF) is an attractive technique for nuclear forensics applications. We evaluated a handheld, portable XRF device by applying an external radiation field (10 mR/h to 17 R/h) using two types of radiography sources: a 60Co radiography camera to observe effects from high-energy gamma emissions and an 192Ir radiography camera to observe effects from several low-energy gamma (0.604, 0.468, and 0.317 MeV) and decay daughter x-ray emissions. External radiation tests proved that radiation, in general, has a significant effect on the dead time or background at dose rates over 1 R/hr for both the 192Ir and 60Co sources.

  14. Density dependence of the nuclear symmetry energy from measurements of neutron radii in nuclei

    SciTech Connect

    Viñas, X.; Centelles, M.; Roca-Maza, X.; Warda, M.

    2014-07-23

    We study the density dependence of the nuclear symmetry energy, characterized by its slope parameter L, by means of the information provided by the neutron radius and the neutron skin thickness in finite nuclei. These quantities are extracted from the analysis of data obtained in antiprotonic atoms, from the parity-violating asymmetry at low-momentum transfer in polarized electron scattering in {sup 208}Pb, and from the electric dipole polarizability obtained via polarized proton inelastic scattering at forward angles in {sup 208}Pb. All these experiments provide different constraints on the slope L of the symmetry energy but the corresponding values have a considerable overlap in a range around 50 MeV ≤ L ≤ 70 MeV, in a reasonable agreement with other estimates that use different observables and methods to extract L.

  15. Measurements of hadron mean free path for the particle-producing collisions in nuclear matter

    NASA Technical Reports Server (NTRS)

    Strugalski, Z.

    1985-01-01

    It is not obvious a priority that the cross-section for a process in hadron collisions with free nucleons is the same as that for the process in hadron collisions with nucleons inside a target nucleus. The question arises: what is the cross-section for a process in a hadron collision with nucleon on inside the atomic nucleus. The answer to it must be found in experiments. The mean free path for particle-producing collisions of pions in nuclear matter is determined experimentally using pion-xenon nucleus collisions at 3.5 GeV/c momentum. Relation between the mean free path in question lambda sub in nucleons fm squared and the cross-section in units of fm squared/nucleon for collisions of the hadron with free nucleon is: lambda sub i = k/cross section sub i, where k = 3.00 plus or minus 0.26.

  16. Beta spectrum measurements for steam generators at the Sequoyah Nuclear Plant

    SciTech Connect

    Farrell, W.E.; Hudson, C.G. )

    1985-04-01

    This paper reports on a study performed during two consecutive outages at the Sequoyah Nuclear Plant to determine the relative responses of instruments and dosimeters to the beta-gamma radiation fields in the steam generators. Eberline RO-7-BM and Ro-2A ion chamber survey instruments were used in the study along with standard and modified Panasonic UD-802 thermoluminescent dosimeters (TLDs) and three types of extremity TLDs. The average and maximum beta energies present in the steam generators were estimated by three separate methods. TLD responses to irradiations with steam generator diaphragms were compared to survey instrument responses, and the use of instrument beta correction factors was evaluated. Extremity TLDs were also exposed to a steam generator diaphragm, and apparent beta correction factors were determined. The overall conclusion of the study was that the average beta energy in the steam generators was bout 100 keV and, as a result, normal protective clothing was adequate to protect workers.

  17. Tomographic gamma scanning (TGS) to measure inhomogeneous nuclear material matrices from future fuel cycles

    SciTech Connect

    Estep, R.J.; Prettyman, T.H.; Sheppard, G.A.

    1993-06-01

    Current methods for the non-destructive assay (NDA) of special nuclear materials (SNM) in 208-L drums can give assay errors of 100% or more when the drum matrix and/or radionuclide distribution is nonuniform. To address this problem, we have developed the tomographic-gamma-scanner (TGS) method for assaying heterogeneous drummed SNM. TGS improves on the well-established segmented-gamma-scanner (SGS) method by performing low-resolution tomographic emission and transmission scans on the drum, yielding coarse three-dimensional images of the matrix density and radionuclide distributions. The images are used to make accurate, point-to-point attenuation corrections. The TGS geometric counting efficiency is 60% that of a typical SGS device, allowing a TGS assay time of only 28 min per drum with a one-detector system. TGS may also be useful for non-destructive examination (NDE). Currently, TGS is the only practical method of imaging SNM in drums.

  18. Low-frequency electromagnetic measurements as a zero-time discriminant of nuclear and chemical explosions -- OSI research final report

    SciTech Connect

    Sweeney, J. J.

    1996-12-01

    This is the final report on a series of investigations of low frequency (1-40 Hz) electromagnetic signals produced by above ground and underground chemical explosions and their use for confidence building under the Comprehensive Test-Ban Treaty. I conclude that low frequency electromagnetic measurements can be a very powerful tool for zero-time discrimination of chemical and nuclear explosions for yields of 1 Kt or greater, provided that sensors can be placed within 1-2 km of the suspected detonation point in a tamper-proof, low noise environment. The report includes descriptions and analyses of low frequency electromagnetic measurements associated with chemical explosions carried out in a variety of settings (shallow borehole, open pit mining, underground mining). I examine cavity pressure data from the Non-Proliferation Experiment (underground chemical explosion) and present the hypothesis that electromagnetic signals produced by underground chemical explosions could be produced during rock fracturing. I also review low frequency electromagnetic data from underground nuclear explosions acquired by Lawrence Livermore National Laboratory during the late 1980s.

  19. Recent analysis of magnetic field and beta particle measurements of the Starfish nuclear burst plasma expansion and collapse.

    NASA Astrophysics Data System (ADS)

    Dyal, P.

    2004-12-01

    Five spacecraft located 100 to 1000 kilometers around the Starfish nuclear burst measured the expansion and collapse of the plasma bubble produced in the geomagnetic field and early time injection into the inner Van Allen radiation belt. The bubble evolved into an elongated shape 2400 km along the magnetic field lines and 700 km across in 1.2 seconds and required approximately 15 seconds to collapse. After the magnetic bubble reached its maximum size instabilities and fluting permitted the beta emitting fission fragments to continue to expand. This process injected a flux measuring 2.5x1010 beta/cm2sec into the most intense region of the artificial belt mapped by the Injun I spacecraft 10 hours later.

  20. Measurements of proton-proton and proton-antiproton elastic scattering at the European Center for Nuclear Research Intersecting Storage Rings

    NASA Astrophysics Data System (ADS)

    Amos, N. A.

    Proton-proton and proton-anitproton elastic scattering were measured at the CERN Intersecting Storage rings. Using the optical theorem, the total nuclear cross sections was extracted for these collisions. By measuring the interference between the Coulomb amplitude and the nuclear amplitude rho, the ratio of the real part to the imaginary part of the forward nuclear elastic scattering amplitude was found. Further, the nuclear slope parameter was extracted in the forward direction. The elastic scattering measurements were made at small scattering angles (approx. 1 milliradian), demanding that the detectors be placed close to the beams. Normalization of the data was performed by two methods: Van der Meer calibrations were performed on sets of luminosity monitor counters, the known Coulomb differential scattering cross section fixed the normalization scale.

  1. Development of Neutron Polarization Measurement System for Studying NN interaction in Nuclear Medium

    NASA Astrophysics Data System (ADS)

    Yasuda, J.; Wakasa, T.; Dozono, M.; Fukunaga, T.; Gotanda, S.; Hatanaka, K.; Kanaya, Y.; Maeda, Y.; Maeda, Y.; Miki, K.; Nishio, Y.; Noro, T.; Ohnaka, K.; Sakaguchi, S.; Sakemi, Y.; Sekiguchi, K.; Tamii, A.; Taguchi, T.; Wada, Y.

    2016-02-01

    We have developed the neutron polarization measurement system to perform the first polarization-transfer measurement for the exclusive (p,np) reaction. For the neutron polarization measurement, we have reconstructed the neutron polarimeter NPOL3. The NPOL3 system has been calibrated by using the polarized neutron from the 2H(p→,n→) reaction, and the resulting effective analyzing power is Ay:eff = 0.127. For the exclusive measurement, the Large Acceptance Spectrometer (LAS) has been used for the recoil proton detection. The energy resolution of 6 MeV is achieved for separation energy, which is sufficient to separate the 1s and 1p orbits for light nuclei.

  2. Nuclear-accident dosimetry: measurements at the Los Alamos SHEBA critical assembly

    SciTech Connect

    Vasilik, D.G.; Martin, R.W.; Fuller, D.

    1981-07-01

    Criticality dosimeters were exposed to different degraded neutron and gamma-ray energy spectra from the Los Alamos Solution High Energy Burst Assembly (SHEBA). The liquid critical test assembly was operated in the continuous mode to provide a mixed source of neutron and gamma-ray radiation for the evaluation of Los Alamos criticality detector systems. Different neutron and gamma-ray spectra were generated by operating the reactor (a) shielded by 12 cm of Lucite, (b) unshielded, (c) shielded by 20 cm of concrete, and (d) shielded by 15 cm of steel. This report summarizes the dosimetry measurements conducted for these different configurations. In-air measurements were conducted with shielded and unshielded area and personnel dosimeters. Phantom measurements were made using personnel dosimeters. Combined blood-sodium and hair sulfur activation measurements of absorbed dose were also made. In addition, indium foils placed on phantoms were evaluated for the purpose of screening personnel for radiation exposure.

  3. Nuclear Targets for a Precision Measurement of the Neutral Pion Radiative Width

    SciTech Connect

    Martel, Philippe; Clinton, Eric; McWilliams, R.; Lawrence, Dave; Miskimen, Rory; Ahmidouch, Abdellah; Ambrozewicz, Pawel; Asaturyan, Arshak; Baker, O.; Benton, LaRay; Bernstein, Aron; Cole, Philip; Collins, Patrick; Dale, Daniel; Danagoulian, Samuel; Davidenko, G.; Demirchyan, Raphael; Deur, Alexandre; DOLGOLENKO, A.; Dzyubenko, Georgiy; Evdokimov, Anatoly; Feng, JIng; Gabrielyan, Marianna; Gan, Liping; Gasparian, Ashot; Glamazdin, Oleksandr; Goryachev, Vladimir; Gyurjyan, Vardan; Hardy, K.; Ito, Mark; Khandaker, Mahbubul; Kingsberry, Paul; Kolarkar, Ameya; Konchatnyi, Mykhailo; Korchin, O.; Korsch, Wolfgang; Kowalski, Stanley; Kubantsev, Mikhail; Kubarovsky, Valery; LARIN, Ilya; MATVEEV, V.; McNulty, Dustin; Milbrath, Brian; Minehart, Ralph; Mochalov, Vasiliy; Mtingwa, Sekazi; Nakagawa, Itaru; Overby, Steven; Pasyuk, Evgueni; Payen, Marvin; Pedroni, Ronald; Prok, Yelena; Ritchie, Barry; Salgado, Carlos; Sitnikov, Anatoly; Sober, Daniel; Stephens, W.; Teymurazyan, Aram; Underwood, Jarreas; VASILIEV, A.; VEREBRYUSOV, V.; Vishnyakov, Vladimir; Wood, Michael

    2009-12-01

    A technique is presented for precision measurements of the area densities, density * T, of approximately 5% radiation length carbon and 208Pb targets used in an experiment at Jefferson Laboratory to measure the neutral pion radiative width. The precision obtained in the area density for the carbon target is +/- 0.050%, and that obtained for the lead target through an x-ray attenuation technique is +/- 0.43%.

  4. Nuclear targets for a precision measurement of the neutral pion radiative width

    NASA Astrophysics Data System (ADS)

    Martel, P.; Clinton, E.; McWilliams, R.; Lawrence, D.; Miskimen, R.; Ahmidouch, A.; Ambrozewicz, P.; Asratyan, A.; Baker, K.; Benton, L.; Bernstein, A.; Cole, P.; Collins, P.; Dale, D.; Danagoulian, S.; Davidenko, G.; Demirchyan, R.; Deur, A.; Dolgolenko, A.; Dzyubenko, G.; Evdokimov, A.; Feng, J.; Gabrielyan, M.; Gan, L.; Gasparian, A.; Glamazdin, O.; Goryachev, V.; Gyurjyan, V.; Hardy, K.; Ito, M.; Khandaker, M.; Kingsberry, P.; Kolarkar, A.; Konchatnyi, M.; Korchin, O.; Korsch, W.; Kowalski, S.; Kubantsev, M.; Kubarovsky, V.; Larin, I.; Matveev, V.; McNulty, D.; Milbrath, B.; Minehart, R.; Mochalov, V.; Mtingwa, S.; Nakagawa, I.; Overby, S.; Pasyuk, E.; Payen, M.; Pedroni, R.; Prok, Y.; Ritchie, B.; Salgado, C.; Sitnikov, A.; Sober, D.; Stephens, W.; Teymurazyan, A.; Underwood, J.; Vasiliev, A.; Verebryusov, V.; Vishnyakov, V.; Wood, M.

    2009-12-01

    A technique is presented for precision measurements of the area densities, ρT, of approximately 5% radiation length carbon and 208Pb targets used in an experiment at Jefferson Laboratory to measure the neutral pion radiative width. The precision obtained in the area density for the carbon target is ±0.050%, and that obtained for the lead target through an X-ray attenuation technique is ±0.43%.

  5. Gross Gamma Dose Rate Measurements for TRIGA Spent Nuclear Fuel Burnup Validation

    SciTech Connect

    Winston, Philip Lon; Sterbentz, James William

    2001-04-01

    Gross gamma-ray dose rates from six spent TRIGA fuel elements were measured and compared to calculated values as a means to validate the reported element burnups. A newly installed and functional gamma-ray detection subsystem of the In-Cell Examination System was used to perform the measurements and is described in some detail. The analytical methodology used to calculate the corresponding dose rates is presented along with the calculated values. Comparison of the measured and calculated dose rates for the TRIGA fuel elements indicates good agreement (less than a factor of 2 difference). The intent of the subsystem is to measure the gross gamma dose rate and correlate the measurement to a calculated dose rate based on the element s known burnup and other pertinent spent fuel information. Although validation of the TRIGA elements’ burnup is of primary concern in this paper, the measurement and calculational techniques can be used to either validate an element’s reported burnup or provide a burnup estimate for an element with an unknown burnup.

  6. Gross Gamma Dose Rate Measurements for TRIGA Spent Nuclear Fuel Burnup Validation

    SciTech Connect

    Winston, P.L.; Sterbentz, J.W.

    2002-07-01

    Gross gamma-ray dose rates from six spent TRIGA fuel elements were measured and compared to calculated values as a means to validate the reported element burnups. A newly installed and functional gamma-ray detection subsystem of the In-Cell Examination System was used to perform the measurements and is described in some detail. The analytical methodology used to calculate the corresponding dose rates is presented along with the calculated values. Comparison of the measured and calculated dose rates for the TRIGA fuel elements indicates good agreement (less than a factor of 2 difference). The intent of the subsystem is to measure the gross gamma dose rate and correlate the measurement to a calculated dose rate based on the element s known burnup and other pertinent spent fuel information. Although validation of the TRIGA elements' burnup is of primary concern in this paper, the measurement and calculational techniques can be used to either validate an element's reported burnup or provide a burnup estimate for an element with an unknown burnup. (authors)

  7. Nuclear Heating Measurement in Critical Facilities and Experimental Validation of Code and Libraries - An Application to Prompt and Delayed γ Nuclear Data Needs

    NASA Astrophysics Data System (ADS)

    Blaise, P.; Di Salvo, J.; Vaglio-Gaudard, C.; Bernard, D.; Amharrak, H.; Lemaire, M.; Ravaux, S.

    Energy from prompt and delayed gammas in actual and future nuclear systems are more and more taken into account into design studies as they play an important role in the assessment of performance and safety concerns. Their incomplete knowledge (both prompt and delayed) require to take conservative design margins on local dimensioning parameters, thus reducing the awaited performances or flexibility of these facilities, with costs that are far from being negligible. The local energy photon deposit must be accurately known for Generation-III (Gen-III), Generation-IV (Gen-IV) or the new MTR Jules Horowitz Reactor (JHR). The last 2 decades has seen the realization, in Zero Power Reactors (ZPR), of several programs partially devoted to γ-heating measurements. Experimental programs were and are still conducted in different Cadarache facilities such as MASURCA (for SFR), and later in MINERVE and EOLE (for JHR and Gen-III reactors). The adequacy of the γ-heating calculation was compared to experimental data using thermo-luminescent (TL) detectors and γ-fission chambers. Inconsistencies in C/E and associated uncertainties led to improvement of both libraries and experimental techniques. For these last one, characterization for TL and optically stimulated (OSL) detectors (calibration, individual response), and Monte Carlo calculation of charge repartition in those detectors and their environment were carefully checked and optimized. This step enabled to reduce the associated experimental uncertainty by a factor of 2 (8% at 2σ). Nevertheless, interpretation of integral experiment with updated calculation schemes and improved experimental techniques still tend to prove that there are some nuclei for which there are missing or erroneous data, mainly in structural and absorbing materials. New integral and differential measurements are needed to guide new evaluation efforts, which could benefit from consolidated theoretical and experimental modeling techniques.

  8. Measurements of gamma-ray production cross sections for shielding materials of space nuclear systems

    NASA Technical Reports Server (NTRS)

    Orphan, V. J.; John, J.; Hoot, C. G.

    1972-01-01

    Measurements of secondary gamma ray production from neutron interactions have been made over the entire energy range of interest in shielding applications. The epithermal capture gamma ray yields for both resolved gamma ray lines and continuum have been measured from thermal energies to 100 KeV for natural tungsten and U-238, two important candidate shield materials in SNAP reactor systems. Data are presented to illustrate the variation of epithermal capture gamma ray yields with neutron energy. The gamma ray production cross sections from (n,xy) reactions have been measured for Fe and Al from the threshold energies for inelastic scattering to approximately 16 MeV. Typical Fe and Al cross sections obtained with high-neutron energy resolution and averaged over broad neutron-energy groups are presented.

  9. Feasibility of a nuclear gauge for fuel quantity measurement aboard aircraft

    NASA Technical Reports Server (NTRS)

    Signh, J. J.; Mall, G. H.; Sprinkle, D. R.; Chegini, H.

    1986-01-01

    Capacitance fuel gauges have served as the basis for fuel quantity indicating systems in aircraft for several decades. However, there have been persistent reports by the airlines that these gauges often give faulty indications due to microbial growth and other contaminants in the fuel tanks. This report describes the results of a feasibility study of using gamma ray attenuation as the basis for measuring fuel quantity in the tanks. Studies with a weak Am-241 59.5-keV radiation source indicate that it is possible to continuously monitor the fuel quantity in the tanks to an accuracy of better than 1 percent. These measurements also indicate that there are easily measurable differences in the physical properties and resultant attenuation characteristics of JP-4, JP-5, and Jet A fuels. The experimental results, along with a suggested source-detector geometrical configuration are described.

  10. Assessment of uncertainties in measurement of pH in hostile environments characteristic of nuclear repositories

    SciTech Connect

    Kreider, K.G.; Tarlov, M.J.; Huang, P.H. )

    1991-10-01

    This report focuses on evaluation and characteristics of sputtered thin film pH electrodes which can be used to assess the corrosivity of hot (100{degree}C) aqueous solutions present in nuclear repositories. Sputtered thin films have the advantages of high temperature capability, ruggedness, and low cost. The iridium oxide films were found to have a linear, 58 mV/pH, response to changes in pH. They had little hysteresis but drifted approximately 0.2 V over a period of two days exposure to pH 2--12 solutions. The films were found to be insensitive to interference from most ions such as alkali ions but had redox sensitivity to ferri-/ferrocyanide ions. Although special surface treatments were needed for the films for good adherence at 200{degree}C the films were not degraded after 20 hours exposure at pH 4, 7, and 10 at 200{degree}C. Ruthenium oxide sputtered films performed equally well to the iridium oxide films in parallel tests. The report also contains information on electrochemistry and testing of thin film electrodes and the characterization of the thin films by x-ray photoemission spectroscopy, ultraviolet photoemission spectroscopy, and ion scattering spectroscopy. 123 refs., 29 figs., 7 tabs.

  11. MEASUREMENTS OF THE CONFINEMENT LEAKTIGHTNESS AT THE KOLA NUCLEAR POWER STATION (UNIT 2) IN RUSSIA

    SciTech Connect

    GREENE,G.A.; GUPPY,J.G.

    1998-08-01

    This is the final report on the INSP project entitled, ``Kola Confinement Leaktightness'' conducted by BNL under the authorization of Project Work Plan WBS 1.2.2.1. This project was initiated in February 1993 to assist the Russians to reduce risks associated with the continued operation of older Soviet-designed nuclear power plants, specifically the Kola VVER-440/230 Units 1 and 2, through upgrades in the confinement performance to reduce the uncontrolled leakage rate. The major technical objective of this-project was to improve the leaktightness of the Kola NPP VVER confinement boundaries, through the application of a variety of sealants to penetrations, doors and hatches, seams and surfaces, to the extent that current technology permitted. A related objective was the transfer, through training of Russian staff, of the materials application procedures to the staff of the Kola NPP. This project was part of an overall approach to minimizing uncontrolled releases from the Kola NPP VVER440/230s in the event of a serious accident, and to thereby significantly mitigate the consequences of such an accident. The US provided materials, application technology, and applications equipment for application of sealant materials, surface coatings, potting materials and gaskets, to improve the confinement leaktightness of the Kola VVER-440/23Os. The US provided for training of Russian personnel in the applications technology.

  12. Distributed Raman temperature measurement system for monitoring of nuclear power plant coolant loops

    NASA Astrophysics Data System (ADS)

    Jensen, Fredrik B. H.; Takada, Eiji; Nakazawa, Masaharu; Kakuta, Tsunemi; Yamamoto, Satoshi

    1996-09-01

    A distributed temperature sensor based on Raman scattering in optical fibers has been tested for use as coolant loop monitor in nuclear power plants. Different types of pure- silica-core, polyimide-coated fibers have been subjected to 60Co-gamma-ray and fission-reactor irradiation at varying temperatures. 60Co-gamma-ray irradiations at dose rates from 4.8 kR/h up to 1 MR/h were done. Simultaneous gamma-ray and high temperature experiments up to 300 degrees Celsius have also been performed. The induced loss of the tested fibers was found to saturate with increasing dose at the anti-Stokes and Stokes wavelengths. This feature was then made use of to develop a model for radiation induced loss which was used to make system lifetime predictions. It has also been demonstrated that the induced loss of the optical fibers is favorably affected by high-temperature use. A 10-fold decrease in the radiation- induced loss levels when the system was operated at 300 degrees Celsius was observed, as compared with room- temperature operation. The experiments have shown that with a pure-silica-core, polyimide-coated fiber the temperature sensing capabilities of the RDTS will not be degraded excessively if used at primary coolant loops with an expected upper radiation level of 200 R/hr.

  13. Evidence of neutron leakage at the Fukushima nuclear plant from measurements of radioactive 35S in California.

    PubMed

    Priyadarshi, Antra; Dominguez, Gerardo; Thiemens, Mark H

    2011-08-30

    A recent earthquake and the subsequent tsunami have extensively damaged the Fukushima nuclear power plant, releasing harmful radiation into the environment. Despite the obvious implication for human health and the surrounding ecology, there are no quantitative estimates of the neutron flux leakage during the weeks following the earthquake. Here, using measurements of radioactive (35)S contained in sulfate aerosols and SO(2) gas at a coastal site in La Jolla, California, we show that nearly 4 × 10(11) neutrons per m(2) leaked at the Fukushima nuclear power plant before March 20, 2011. A significantly higher (35)SO(2-)(4) activity as measured on March 28 is in accord with neutrons escaping the reactor core and being absorbed by the coolant seawater (35)Cl to produce (35)S by a (n, p) reaction. Once produced, (35)S oxidizes to (35)SO(2) and (35)SO(2-)(4) and was then transported to Southern California due to the presence of strong prevailing westerly winds at this time. Based on a moving box model, we show that the observed activity enhancement in (35)SO(2-)(4) is compatible with long-range transport of the radiation plume from Fukushima. Our model predicts that (35)SO(2-)(4), the concentration in the marine boundary layer at Fukushima, was approximately 2 × 10(5) atoms per m(3), which is approximately 365 times above expected natural concentrations. These measurements and model calculations imply that approximately 0.7% of the total radioactive sulfate present at the marine boundary layer at Fukushima reached Southern California as a result of the trans-Pacific transport. PMID:21844372

  14. Evidence of neutron leakage at the Fukushima nuclear plant from measurements of radioactive 35S in California

    PubMed Central

    Priyadarshi, Antra; Dominguez, Gerardo; Thiemens, Mark H.

    2011-01-01

    A recent earthquake and the subsequent tsunami have extensively damaged the Fukushima nuclear power plant, releasing harmful radiation into the environment. Despite the obvious implication for human health and the surrounding ecology, there are no quantitative estimates of the neutron flux leakage during the weeks following the earthquake. Here, using measurements of radioactive 35S contained in sulfate aerosols and SO2 gas at a coastal site in La Jolla, California, we show that nearly 4 × 1011 neutrons per m2 leaked at the Fukushima nuclear power plant before March 20, 2011. A significantly higher activity as measured on March 28 is in accord with neutrons escaping the reactor core and being absorbed by the coolant seawater 35Cl to produce 35S by a (n, p) reaction. Once produced, 35S oxidizes to and and was then transported to Southern California due to the presence of strong prevailing westerly winds at this time. Based on a moving box model, we show that the observed activity enhancement in is compatible with long-range transport of the radiation plume from Fukushima. Our model predicts that , the concentration in the marine boundary layer at Fukushima, was approximately 2 × 105 atoms per m3, which is approximately 365 times above expected natural concentrations. These measurements and model calculations imply that approximately 0.7% of the total radioactive sulfate present at the marine boundary layer at Fukushima reached Southern California as a result of the trans-Pacific transport. PMID:21844372

  15. Measurements of nuclear reaction cross sections for 183, 184W + 238U near the interaction barrier

    NASA Astrophysics Data System (ADS)

    Himmele, G.; Backe, H.; Butler, P. A.; Habs, D.; Metag, V.; Specht, H. J.; Wilhelmy, J. B.

    1983-08-01

    The cross sections for inelastic scattering, nucleon transfer and transfer-induced fission have been measured for 184W + 238U as a function of bombarding energy near the interaction barrier. The inelastic scattering cross section for 183W + 238U has also been measured at one energy. The two- nucleon and one-nucleon transfer cross sections, for neutron stripping at least, are similar in magnitude which suggests a substantial enhancement for the two-nucleon transfers. The probabilities for fission following the transfer reactions show in some cases strong dependence on bombarding energy, which demonstrates that simultaneous Coulomb excitation plays an important part in transfer reactions between very heavy ions.

  16. Ambient Dose Equivalent measured at the Instituto Nacional de Cancerología Department of Nuclear Medicine

    NASA Astrophysics Data System (ADS)

    Ávila, O.; Torres-Ulloa, C. L.; Medina, L. A.; Trujillo-Zamudio, F. E.; de Buen, I. Gamboa; Buenfil, A. E.; Brandan, M. E.

    2010-12-01

    Ambient dose equivalent values were determined in several sites at the Instituto Nacional de Cancerología, Departmento de Medicina Nuclear, using TLD-100 and TLD-900 thermoluminescent dosemeters. Additionally, ambient dose equivalent was measured at a corridor outside the hospitalization room for patients treated with 137Cs brachytherapy. Dosemeter calibration was performed at the Instituto Nacional de Investigaciones Nucleares, Laboratorio de Metrología, to known 137Cs gamma radiation air kerma. Radionuclides considered for this study are 131I, 18F, 67Ga, 99mTc, 111In, 201Tl and 137Cs, with main gamma energies between 93 and 662 keV. Dosemeters were placed during a five month period in the nuclear medicine rooms (containing gamma-cameras), injection corridor, patient waiting areas, PET/CT study room, hot lab, waste storage room and corridors next to the hospitalization rooms for patients treated with 131I and 137Cs. High dose values were found at the waste storage room, outside corridor of 137Cs brachytherapy patients and PET/CT area. Ambient dose equivalent rate obtained for the 137Cs brachytherapy corridor is equal to (18.51±0.02)×10-3 mSv/h. Sites with minimum doses are the gamma camera rooms, having ambient dose equivalent rates equal to (0.05±0.03)×10-3 mSv/h. Recommendations have been given to the Department authorities so that further actions are taken to reduce doses at high dose sites in order to comply with the ALARA principle (as low as reasonably achievable).

  17. Field experiment provides ground truth for surface nuclear magnetic resonance measurement

    USGS Publications Warehouse

    Knight, R.; Grunewald, E.; Irons, T.; Dlubac, K.; Song, Y.; Bachman, H.N.; Grau, B.; Walsh, D.; Abraham, J.D.; Cannia, J.

    2012-01-01

    The need for sustainable management of fresh water resources is one of the great challenges of the 21st century. Since most of the planet's liquid fresh water exists as groundwater, it is essential to develop non-invasive geophysical techniques to characterize groundwater aquifers. A field experiment was conducted in the High Plains Aquifer, central United States, to explore the mechanisms governing the non-invasive Surface NMR (SNMR) technology. We acquired both SNMR data and logging NMR data at a field site, along with lithology information from drill cuttings. This allowed us to directly compare the NMR relaxation parameter measured during logging, T 2, to the relaxation parameter T 2 * measured using the SNMR method. The latter can be affected by inhomogeneity in the magnetic field, thus obscuring the link between the NMR relaxation parameter and the hydraulic conductivity of the geologic material. When the logging T 2 data were transformed to pseudo-T 2 * data, by accounting for inhomogeneity in the magnetic field and instrument dead time, we found good agreement with T 2 * obtained from the SNMR measurement. These results, combined with the additional information about lithology at the site, allowed us to delineate the physical mechanisms governing the SNMR measurement. Such understanding is a critical step in developing SNMR as a reliable geophysical method for the assessment of groundwater resources. Copyright 2012 by the American Geophysical Union.

  18. Comparison of measured and calculated dose rates near nuclear medicine patients.

    PubMed

    Yi, Y; Stabin, M G; McKaskle, M H; Shone, M D; Johnson, A B

    2013-08-01

    Widely used release criteria for patients receiving radiopharmaceuticals (NUREG-1556, Vol. 9, Rev.1, Appendix U) are known to be overly conservative. The authors measured external exposure rates near patients treated with I, Tc, and F and compared the measurements to calculated values using point and line source models. The external exposure dose rates for 231, 11, and 52 patients scanned or treated with I, Tc, and F, respectively, were measured at 0.3 m and 1.0 m shortly after radiopharmaceutical administration. Calculated values were always higher than measured values and suggested the application of "self-shielding factors," as suggested by Siegel et al. in 2002. The self-shielding factors of point and line source models for I at 1 m were 0.60 ± 0.16 and 0.73 ± 0.20, respectively. For Tc patients, the self-shielding factors for point and line source models were 0.44 ± 0.19 and 0.55 ± 0.23, and the values were 0.50 ± 0.09 and 0.60 ± 0.12, respectively, for F (all FDG) patients. Treating patients as unshielded point sources of radiation is clearly inappropriate. In reality, they are volume sources, but treatment of their exposures using a line source model with appropriate self-shielding factors produces a more realistic, but still conservative, approach for managing patient release. PMID:23799503

  19. Development of self-interrogation neutron resonance densitometry (sinrd) to measure the fissile content in nuclear fuel

    NASA Astrophysics Data System (ADS)

    LaFleur, Adrienne Marie

    The development of non-destructive assay (NDA) capabilities to directly measure the fissile content in spent fuel is needed to improve the timely detection of the diversion of significant quantities of fissile material. Currently, the International Atomic Energy Agency (IAEA) does not have effective NDA methods to verify spent fuel and recover continuity of knowledge in the event of a containment and surveillance systems failure. This issue has become increasingly critical with the worldwide expansion of nuclear power, adoption of enhanced safeguards criteria for spent fuel verification, and recent efforts by the IAEA to incorporate an integrated safeguards regime. In order to address these issues, the use of Self-Interrogation Neutron Resonance Densitometry (SINRD) has been developed to improve existing nuclear safeguards and material accountability measurements. The following characteristics of SINRD were analyzed: (1) ability to measure the fissile content in Light Water Reactors (LWR) fuel assemblies and (2) sensitivity and penetrability of SINRD to the removal of fuel pins from an assembly. The Monte Carlo Neutral Particle eXtended (MCNPX) transport code was used to simulate SINRD for different geometries. Experimental measurements were also performed with SINRD and were compared to MCNPX simulations of the experiment to verify the accuracy of the MCNPX model of SINRD. Based on the results from these simulations and measurements, we have concluded that SINRD provides a number of improvements over current IAEA verification methods. These improvements include: (1) SINRD provides absolute measurements of burnup independent of the operator's declaration. (2) SINRD is sensitive to pin removal over the entire burnup range and can verify the diversion of 6% of fuel pins within 3o from LWR spent LEU and MOX fuel. (3) SINRD is insensitive to the boron concentration and initial fuel enrichment and can therefore be used at multiple spent fuel storage facilities. (4) The

  20. Detection of the water level in fractured phreatic aquifers using nuclear magnetic resonance (NMR) geophysical measurements

    NASA Astrophysics Data System (ADS)

    Gev, Israel; Goldman, Mark; Rabinovich, Boris; Rabinovich, Michael; Issar, Arie

    1996-06-01

    Correlation of geophysical data collected using the NMR method in the Negev Desert, Israel, with hydrogeological data from nearby observation wells is presented. The experiment was conducted near Kibbutz Revivim in the Besor drainage system (Fig. 1). The objective of the survey was to detect groundwater layers in the Quaternary cover filling and Eocene fractured aquifers down to a depth of 100 m. The experiment was performed using a combination of two different geophysical techniques, namely the NMR and time domain electromagnetic (TDEM) methods. The geophysical results were verified by measuring the water level in three observation wells, two of which were drilled several months after the geophysical survey was carried out. The water level measured in these follow-up observation wells shortly after drilling did not coincide with the geophysical data. However, it settled over a period of time and finally stabilized at a depth very similar to that obtained from the NMR measurements. This phenomenon is caused by the fractured nature of the phreatic aquifer. Since the flow of water in such aquifers is confined by the fractures, the appearance of water in the well during or shortly after drilling is determined solely by the intersection of the well and the fracture. Our experiments showed that geophysical measurements in fractured phreatic aquifers may have a distinct advantage over direct borehole measurements, since the former average the depth to the water table over large areas (several thousand square meters) while the latter are limited by the area of the borehole cross-section (several tens of square centimeters).

  1. Identification of a Debris Cloud from the Nuclear Powered SNAPSHOT Satellite with Haystack Radar Measurements

    NASA Technical Reports Server (NTRS)

    Stokely, C.; Stansbery, E.

    2006-01-01

    Data from the MIT Lincoln Laboratory (MIT/LL) Long Range Imaging Radar (known as the Haystack radar) have been used in the past to examine families of objects from individual satellite breakups or families of orbiting objects that can be isolated in altitude and inclination. This is possible because for some time after a breakup, the debris cloud of particles can remain grouped together in similar orbit planes. This cloud will be visible to the radar, in fixed staring mode, for a short time twice each day, as the orbit plane moves through the field of view. There should be a unique three-dimensional pattern in observation time, range, and range rate which can identify the cloud. Eventually, through slightly differing precession rates of the right ascension of ascending node of the debris cloud, the observation time becomes distributed so that event identification becomes much more difficult. Analyses of the patterns in observation time, range, and range rate have identified good debris candidates released from the polar orbiting SNAPSHOT satellite (International Identifier: 1965-027A). For orbits near 90o inclination, there is essentially no precession of the orbit plane. The SNAPSHOT satellite is a well known nuclear powered satellite launched in 1965 to a near circular 1300 km orbit with an inclination of 90.3o. This satellite began releasing debris in 1979 with new pieces being discovered and cataloged over the years. 51 objects are still being tracked by the United States Space Surveillance Network. An analysis of the Haystack data has identified at least 60 pieces of debris separate from the 51 known tracked debris pieces, where all but 2 of the 60 pieces have a size less than 10cm. The altitude and inclination (derived from range-rate with a circular orbit assumption) are consistent with the SNAPSHOT satellite and its tracked debris cloud.

  2. Measurement and modelling of reactive transport in geological barriers for nuclear waste containment.

    PubMed

    Xiong, Qingrong; Joseph, Claudia; Schmeide, Katja; Jivkov, Andrey P

    2015-11-11

    Compacted clays are considered as excellent candidates for barriers to radionuclide transport in future repositories for nuclear waste due to their very low hydraulic permeability. Diffusion is the dominant transport mechanism, controlled by a nano-scale pore system. Assessment of the clays' long-term containment function requires adequate modelling of such pore systems and their evolution. Existing characterisation techniques do not provide complete pore space information for effective modelling, such as pore and throat size distributions and connectivity. Special network models for reactive transport are proposed here using the complimentary character of the pore space and the solid phase. This balances the insufficient characterisation information and provides the means for future mechanical-physical-chemical coupling. The anisotropy and heterogeneity of clays is represented using different length parameters and percentage of pores in different directions. Resulting networks are described as mathematical graphs with efficient discrete calculus formulation of transport. Opalinus Clay (OPA) is chosen as an example. Experimental data for the tritiated water (HTO) and U(vi) diffusion through OPA are presented. Calculated diffusion coefficients of HTO and uranium species are within the ranges of the experimentally determined data in different clay directions. This verifies the proposed pore network model and validates that uranium complexes are diffusing as neutral species in OPA. In the case of U(vi) diffusion the method is extended to account for sorption and convection. Rather than changing pore radii by coarse grained mathematical formula, physical sorption is simulated in each pore, which is more accurate and realistic. PMID:26524292

  3. Validating mass spectrometry measurements of nuclear materials via a non-contact volume analysis method of ion sputter craters

    SciTech Connect

    Willingham, David G.; Naes, Benjamin E.; Fahey, Albert J.

    2015-01-01

    A combination of secondary ion mass spectrometry, optical profilometry and a statistically-driven algorithm was used to develop a non-contact volume analysis method to validate the useful yields of nuclear materials. The volume analysis methodology was applied to ion sputter craters created in silicon and uranium substrates sputtered by 18.5 keV O- and 6.0 keV Ar+ ions. Sputter yield measurements were determined from the volume calculations and were shown to be comparable to Monte Carlo calculations and previously reported experimental observations. Additionally, the volume calculations were used to determine the useful yields of Si+, SiO+ and SiO2+ ions from the silicon substrate and U+, UO+ and UO2+ ions from the uranium substrate under 18.5 keV O- and 6.0 keV Ar+ ion bombardment. This work represents the first steps toward validating the interlaboratory and cross-platform performance of mass spectrometry for the analysis of nuclear materials.

  4. Measurement of the nuclear multiplicity ratio or image hadronization K0s at CLAS

    SciTech Connect

    Daniel, A.; Hicks, K.; Brooks, W. K.; Hakobyan, H.; Adhikari, K. P.; Adikaram, D.; Aghasyan, M.; Amarian, M.; Anghinolfi, M.; Avakian, H.; Baghdasaryan, H.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Bennett, R. P.; Biselli, A. S.; Bookwalter, C.; Briscoe, W. J.; Burkert, V. D.; Carman, D. S.; Casey, L.; Celentano, A.; Chandavar, S.; Cole, P. L.; Contalbrigo, M.; Crede, V.; DʼAngelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Dey, B.; Dickson, R.; Djalali, C.; Dodge, G. E.; Doughty, D.; Egiyan, H.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Gabrielyan, M. Y.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guo, L.; Hanretty, C.; Heddle, D.; Holtrop, M.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jawalkar, S. S.; Jo, H. S.; Joo, K.; Kalantarians, N.; Keller, D.; Khandaker, M.; Khetarpal, P.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Kubarovsky, V.; Kuleshov, S. V.; Kuznetsov, V.; Lu, H. Y.; MacGregor, I. J. D.; Mao, Y.; Markov, N.; Mayer, M.; McAndrew, J.; McKinnon, B.; Meyer, C. A.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Moutarde, H.; Munevar, E.; Nadel-Turonski, P.; Ni, A.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Paolone, M.; Pappalardo, L.; Paremuzyan, R.; Park, K.; Park, S.; Pasyuk, E.; Anefalos Pereira, S.; Phelps, E.; Pisano, S.; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Procureur, S.; Protopopescu, D.; Raue, B. A.; Ricco, G.; Rimal, D.; Ripani, M.; Rosner, G.; Rossi, P.; Sabatié, F.; Saini, M. S.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seraydaryan, H.; Sharabian, Y. G.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Stepanyan, S. S.; Stepanyan, S.; Strauch, S.; Taiuti, M.; Tang, W.; Taylor, C. E.; Tkachenko, S.; Ungaro, M.; Vernarsky, B.; Vineyard, M. F.; Voskanyan, H.; Voutier, E.; Watts, D. P.; Weinstein, L. B.; Weygand, D. P.; Wood, M. H.; Zana, L.; Zachariou, N.; Zhao, B.; Zhao, Z. W.

    2011-11-01

    The influence of cold nuclear matter on lepto-production of hadrons in semi-inclusive deep inelastic scattering is measured using the CLAS detector in Hall B at Jefferson Lab and a 5.014 GeV electron beam. We report the K0s multiplicity ratios for targets of C, Fe, and Pb relative to deuterium as a function of the fractional virtual photon energy z transferred to the K0sand the transverse momentum squared p2T of the K0s. We find that the multiplicity ratios for K0s are reduced in the nuclear medium at high z and low p2T, with a trend for the K0s transverse momentum to be broadened in the nucleus for large p2T.

  5. Application of dosimetry measurements to analyze the neutron activation of a stainless steel sample in a training nuclear reactor

    NASA Astrophysics Data System (ADS)

    Ródenas, J.; Gallardo, S.; Weirich, F.; Hansen, W.

    2014-11-01

    All materials present in the core of a nuclear reactor are activated by neutron irradiation. The activity so generated produces a dose around the material. This dose is a potential risk for workers in the surrounding area when materials are withdrawn from the reactor. Therefore, it is necessary to assess the activity generated and the dose produced. In previous works, neutron activation of control rods and doses around the storage pool where they are placed have been calculated for a Boiling Water Reactor using the MCNP5 code based on the Monte Carlo method. Most of the activation is produced indeed in stainless steel components of the nuclear reactor core not only control rods. In this work, a stainless steel sample is irradiated in the Training Reactor AKR-2 of the Technical University Dresden. Dose measurements around the sample have been performed for different times after the irradiation. Experimental dosimetric values are compared with results of Monte Carlo simulation of the irradiation. Comparison shows a good agreement. Hence, the activation Monte Carlo model can be considered as validated.

  6. Measurement of the 19F(α,n) Cross Section for Nuclear Safeguards Science

    NASA Astrophysics Data System (ADS)

    Reingold, C. S.; Cizewski, J. A.; Peters, W. A.; Clement, R. R. C.; Bardayan, D. W.; Smith, M. S.; Stech, E.; Strauss, S.; Tan, W. P.; Wiescher, M.; Madurga, M.; Vandle Collaboration

    2013-10-01

    A precise measurement of the 19F(α,n) cross section will improve Non Destructive Assays (NDA) of UF6 and other actinide-fluoride samples via neutron detection techniques. We will determine the cross section with two complementary approaches. First, we will bombard a LaF3 target with a pulsed 4He beam from the Notre Dame FN tandem accelerator; second, we will send a fluorine beam from the ORNL tandem through a pure helium gas target. The neutron spectra from both of these reactions will be measured using the Versatile Array of Neutron Detectors at Low Energy (VANDLE), and coincident γ rays with a HPGe detector. We report here on data taken with VANDLE and a HPGe detector on a LaF3 target. My poster outlines the motivation for this experiment, explains the stages of this experiment, the current experimental setup, and preliminary data. This work is supported by the NNSA.

  7. Thermal analysis of thermo-gravimetric measurements of spent nuclear fuel oxidation rates

    SciTech Connect

    Cramer, E.R.

    1997-10-09

    A detailed thermal analysis was completed of the sample temperatures in the Thermo-Gravimetric Analysis (TGA) system used to measure irradiated N Reactor fuel oxidation rates. Sample temperatures during the oxidation process did not show the increase which was postulated as a result of the exothermic reactions. The analysis shows the axial conduction of heat in the sample holder effectively removes the added heat and only a very small, i.e., <10 C, increase in temperature is calculated. A room temperature evaporation test with water showed the sample thermocouple sensitivity to be more than adequate to account for a temperature change of approximately 5 C. Therefore, measured temperatures in the TGA are within approximately 10 C of the actual sample temperatures and no adjustments to reported data to account for the heat input from the oxidation process are necessary.

  8. High-precision Penning-trap mass measurements of heavy xenon isotopes for nuclear structure studies

    SciTech Connect

    Neidherr, D.; Cakirli, R. B.; Audi, G.; Lunney, D.; Minaya-Ramirez, E.; Naimi, S.; Beck, D.; Herfurth, F.; Blaum, K.; Boehm, Ch.; George, S.; Breitenfeldt, M.; Rosenbusch, M.; Schweikhard, L.; Casten, R. F.; Herlert, A.; Kowalska, M.; Kellerbauer, A.; Schwarz, S.

    2009-10-15

    With the double Penning-trap mass spectrometer ISOLTRAP at ISOLDE/CERN the masses of the neutron-rich isotopes {sup 136-146}Xe were measured with a relative uncertainty of the order of 10{sup -8} to 10{sup -7}. In particular, the masses of {sup 144-146}Xe were measured for the first time. These new mass values allow one to extend calculations of the mass surface in this region. Proton-Neutron interaction strength, obtained from double differences of binding energies, relate to subtle structural effects, such as the onset of octupole correlations, the growth of collectivity, and its relation to the underlying shell model levels. In addition, they provide a test of density functional calculations.

  9. Precise Lifetime Measurements in Light Nuclei for Benchmarking Modern Ab-initio Nuclear Structure Models

    SciTech Connect

    Lister, C.J.; McCutchan, E.A.

    2014-06-15

    A new generation of ab-initio calculations, based on realistic two- and three-body forces, is having a profound impact on our view of how nuclei work. To improve the numerical methods, and the parameterization of 3-body forces, new precise data are needed. Electromagnetic transitions are very sensitive to the dynamics which drive mixing between configurations. We have made a series of precise (< 3%) measurements of electromagnetic transitions in the A=10 nuclei {sup 10}C and {sup 10}Be by using the Doppler Shift Attenuation method carefully. Many interesting features can be reproduced including the strong α clustering. New measurements on {sup 8}Be and {sup 12}Be highlight the interplay between the alpha clusters and their valence neutrons.

  10. Measurement of the 19F(α,n) Cross Section for Nuclear Safeguards Science

    NASA Astrophysics Data System (ADS)

    Reingold, C. S.; Cizewski, J. A.; Burcher, S.; Manning, B.; Peters, W. A.; Clement, R. R. C.; Smith, M. S.; Bardayan, D. W.; Stech, E.; Tan, W. P.; Madurga, M.; Ilyushkin, S.; Thompson, S.; Vandle Collaboration

    2014-09-01

    A precise measurement of the 19F(α,n) cross section will improve Non Destructive Assays (NDA) of UF6 and other actinide-fluoride samples via neutron detection techniques. The cross section will be determined with two complementary approaches. We have already bombarded a LaF3 target with a pulsed 4He beam from the Notre Dame FN tandem accelerator; next, we will send a fluorine beam from the ORNL tandem through a pure helium gas target. The neutron spectra from both of these reactions will be measured using the Versatile Array of Neutron Detectors at Low Energy (VANDLE), and coincident γ rays with a HPGe detector. We report here on data taken with VANDLE and a HPGe detector on a LaF3 target. This poster outlines the motivation for this experiment, explains the stages of this experiment, and presents both of our experimental setups and preliminary data. A precise measurement of the 19F(α,n) cross section will improve Non Destructive Assays (NDA) of UF6 and other actinide-fluoride samples via neutron detection techniques. The cross section will be determined with two complementary approaches. We have already bombarded a LaF3 target with a pulsed 4He beam from the Notre Dame FN tandem accelerator; next, we will send a fluorine beam from the ORNL tandem through a pure helium gas target. The neutron spectra from both of these reactions will be measured using the Versatile Array of Neutron Detectors at Low Energy (VANDLE), and coincident γ rays with a HPGe detector. We report here on data taken with VANDLE and a HPGe detector on a LaF3 target. This poster outlines the motivation for this experiment, explains the stages of this experiment, and presents both of our experimental setups and preliminary data. This work is supported by the NNSA, NSF, and DOE.

  11. Inferring Nuclear Structure Trends of r-PROCESS Nuclei from β-DECAY Measurements

    NASA Astrophysics Data System (ADS)

    Pereira, J.

    2013-03-01

    The present paper reports on several r-process motivated β-decay experiments undertaken at the National Superconducting Cyclotron Laboratory. β-decay half-lives and β-delayed neutron-emission probabilities were measured for neutron-rich nuclei in the region A=80-110. The data are discussed on the basis of quasi-random phase approximation calculations. The emphasis is made on the impact of these data upon calculations of r-process abundances.

  12. Shock tube technique for measuring opacities at high pressures for gaseous-core nuclear rockets.

    NASA Technical Reports Server (NTRS)

    Patch, R. W.

    1971-01-01

    A new method of opacity determination is described that uses an improved shock tube design and is applicable to measurements of Planck and Rosseland mean opacities in hydrogen or seeded hydrogen at hydrogen partial pressures of 500 atm, at temperatures from 2300 to 8000 K. The selection of seed materials to be added to the gases to make them semiopaque is discussed. Currently favored seeds are silicon and carbon or graphite for reactive seeds, and depleted uranium and tungsten 184 for nonreactive seeds.

  13. The effect of diffusion in internal gradients on nuclear magnetic resonance transverse relaxation measurements

    SciTech Connect

    Muncaci, S.; Ardelean, I.; Boboia, S.

    2013-11-13

    In the present work we study the internal gradient effects on diffusion attenuation of the echo train appearing in the well-known Carr-Purcell-Meiboom-Gill (CPMG) technique, extensively used for transverse relaxation measurements. Our investigations are carried out on two porous ceramics, prepared with the same amount of magnetic impurities (Fe{sub 2}O{sub 3}) but different pore sizes. It is shown that diffusion effects on the CPMG echo train attenuation are strongly influenced by the pore size for the same magnetic susceptibility of the two samples. The experimental results were compared with a theoretical model taking into account the limit of free or restricted diffusion on echo train attenuation. The NMR experiments were performed on water filled samples using a low-field NMR instrument. The porous ceramics were prepared using both the replica technique and the powder compression technique. Magnetic susceptibility measurements indicated close values of the susceptibility constant for the two samples whereas the SEM images indicated different pore sizes. The results reported here may have impact in the interpretation of NMR relaxation measurements of water in soils or concrete samples.

  14. Precise Nuclear Data Measurements Possible with the NIFFTE fissionTPC for Advanced Reactor Designs

    NASA Astrophysics Data System (ADS)

    Towell, Rusty; Niffte Collaboration

    2015-10-01

    The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) Collaboration has applied the proven technology of Time Projection Chambers (TPC) to the task of precisely measuring fission cross sections. With the NIFFTE fission TPC, precise measurements have been made during the last year at the Los Alamos Neutron Science Center from both U-235 and Pu-239 targets. The exquisite tracking capabilities of this device allow the full reconstruction of charged particles produced by neutron beam induced fissions from a thin central target. The wealth of information gained from this approach will allow systematics to be controlled at the level of 1%. The fissionTPC performance will be presented. These results are critical to the development of advanced uranium-fueled reactors. However, there are clear advantages to developing thorium-fueled reactors such as Liquid Fluoride Thorium Reactors over uranium-fueled reactors. These advantages include improved reactor safety, minimizing radioactive waste, improved reactor efficiency, and enhanced proliferation resistance. The potential for using the fissionTPC to measure needed cross sections important to the development of thorium-fueled reactors will also be discussed.

  15. The effect of diffusion in internal gradients on nuclear magnetic resonance transverse relaxation measurements

    NASA Astrophysics Data System (ADS)

    Muncaci, S.; Boboia, S.; Ardelean, I.

    2013-11-01

    In the present work we study the internal gradient effects on diffusion attenuation of the echo train appearing in the well-known Carr-Purcell-Meiboom-Gill (CPMG) technique, extensively used for transverse relaxation measurements. Our investigations are carried out on two porous ceramics, prepared with the same amount of magnetic impurities (Fe2O3) but different pore sizes. It is shown that diffusion effects on the CPMG echo train attenuation are strongly influenced by the pore size for the same magnetic susceptibility of the two samples. The experimental results were compared with a theoretical model taking into account the limit of free or restricted diffusion on echo train attenuation. The NMR experiments were performed on water filled samples using a low-field NMR instrument. The porous ceramics were prepared using both the replica technique and the powder compression technique. Magnetic susceptibility measurements indicated close values of the susceptibility constant for the two samples whereas the SEM images indicated different pore sizes. The results reported here may have impact in the interpretation of NMR relaxation measurements of water in soils or concrete samples.

  16. Contribution of Recently Measured Nuclear Data to Reactor Antineutrino Energy Spectra Predictions

    SciTech Connect

    Estienne, M.; Bui, V.M.; Cucoanes, A.; Elnimr, M.; Giot, L.; Martino, J.; Onillon, A.; Porta, A.; Pronost, G.; Remoto, A.; Yermia, F.; Zakari-Issoufou, A.-A.

    2014-06-15

    The aim of this work is to study the impact of the inclusion of the recently measured β decay properties of the {sup 102,104,105,106,107}Tc, {sup 105}Mo, and {sup 101}Nb nuclei in the calculation of the antineutrino (anti-ν) energy spectra arising after the fissions of the four main fissile isotopes {sup 235,238}U, and {sup 239,241}Pu in PWRs. These β feeding probabilities, measured using the Total Absorption Technique (TAS) at the JYFL facility of Jyväskylä, have been found to play a major role in the γ component of the decay heat for {sup 239}Pu in the 4-3000 s range. Following the fission product summation method, the calculation was performed using the MCNP Utility Reactor Evolution code (MURE) coupled to the experimental spectra built from β decay properties of the fission products taken from evaluated databases. These latest TAS data are found to have a significant effect on the Pu isotope energy spectra and on the spectrum of {sup 238}U showing the importance of their measurement for a better assessment of the reactor anti-ν energy spectrum, as well as importance for fundamental neutrino physics experiments and neutrino applied physics.

  17. Contribution of Recently Measured Nuclear Data to Reactor Antineutrino Energy Spectra Predictions

    NASA Astrophysics Data System (ADS)

    Estienne, M.; Fallot, M.; Cormon, S.; Algora, A.; Bui, V. M.; Cucoanes, A.; Elnimr, M.; Giot, L.; Jordan, D.; Martino, J.; Onillon, A.; Porta, A.; Pronost, G.; Remoto, A.; Taín, J. L.; Yermia, F.; Zakari-Issoufou, A.-A.

    2014-06-01

    The aim of this work is to study the impact of the inclusion of the recently measured β decay properties of the 102,104,105,106,107Tc, 105Mo, and 101Nb nuclei in the calculation of the antineutrino (anti-ν) energy spectra arising after the fissions of the four main fissile isotopes 235,238U, and 239,241Pu in PWRs. These β feeding probabilities, measured using the Total Absorption Technique (TAS) at the JYFL facility of Jyväskylä, have been found to play a major role in the γ component of the decay heat for 239Pu in the 4-3000 s range. Following the fission product summation method, the calculation was performed using the MCNP Utility Reactor Evolution code (MURE) coupled to the experimental spectra built from β decay properties of the fission products taken from evaluated databases. These latest TAS data are found to have a significant effect on the Pu isotope energy spectra and on the spectrum of 238U showing the importance of their measurement for a better assessment of the reactor anti-ν energy spectrum, as well as importance for fundamental neutrino physics experiments and neutrino applied physics.

  18. Conversion electron measurements of 195Au using ICEBall for Nuclear Structure and Astrophysics at the University of Notre Dame

    NASA Astrophysics Data System (ADS)

    Battaglia, Anthony; Tan, Wanpeng; Aprahamian, Ani; Bauder, William; Casarella, Clark; Gurdal, Gulhan; Long, Alexander; Nystrom, Andrew; Siegl, Kevin; Smith, Karl; Smith, Mallory

    2013-10-01

    The Internal Conversion Electron Ball Array (ICEBall) consists of six Si(Li) detectors and it was recently re-comissioned at the University of Notre Dame Nuclear Science Laboratory for spectroscopic studies of heavy nuclei. For the commissioning experiment, a 16 MeV bunched proton beam was used from the FN Tandem for a (p,2n) reaction to populate low spin states of 195Au. Both conversion electrons and gamma-rays were detected in coincidence between ICEBall and a single high-purity germanium detector. A total of 14 conversion coeffcients were measured. The results will be presented and compared to previous results. This work was supported by the National Science Foundation under contract number NSF PHY-1068192. M.P. Metlay, J.X. Saladin, I.Y. Lee, and O. Dietzsch, Nucl. Instrum. Meth. A, 336, 162 (1993).

  19. A critical assembly designed to measure neutronic benchmarks in support of the Space Nuclear Thermal Propulsion program

    NASA Astrophysics Data System (ADS)

    Parma, E. J.; Ball, R. M.; Hoovler, G. S.; Selcow, E. C.; Cerbone, R. J.

    1992-10-01

    A reactor designed to perform criticality experiments in support of the Space Nuclear Thermal Propulsion program is currently in operation at the Sandia National Laboratories' reactor facility. The reactor is a small, water-moderated system that uses highly enriched uranium particle fuel in a 19-element configuration. Its purpose is to obtain neutronic measurements under a variety of experimental conditions that are subsequently used to benchmark reactor-design computer codes. Brookhaven National Laboratory, Babcock & Wilcox, and Sandia National Laboratories participated in determining the reactor's performance requirements, design, follow on experimentation, and in obtaining the licensing approvals. Brookhaven National Laboratory is primarily responsible for the analytical support, Babcock & Wilcox the hardware design, and Sandia National Laboratories the operational safety. All of the team members participate in determining the experimentation requirements, performance, and data reduction. Initial criticality was achieved in October 1989. An over-all description of the reactor is presented along with key design features and safety-related aspects.

  20. Nuclear stopping in heavy-ion collisions at 100 MeV/nucleon from inclusive and exclusive neutral pion measurements

    SciTech Connect

    Badala, A.; Barbera, R.; Palmeri, A.; Pappalardo, G.S.; Riggi, F.; Russo, A.C.; Russo, G.; Turrisi, R. ||

    1996-04-01

    Inclusive and exclusive measurements of neutral pions in heavy-ion collisions around 100 MeV/nucleon, carried out in a near 4{pi} geometry, have been analyzed to obtain information on the nuclear stopping of the projectile. Stopping of the projectile has been investigated by the analysis of the source velocity, of the distribution of the energetic products of the collisions, and of the associated rapidity distribution of the baryon matter. Collisions were classified according to their centrality by the charged particle multiplicity. Clear evidence for this phenomenon has been obtained by the study of different observables. Both stopping and reabsorption effects play an essential role in the interpretation of the results. {copyright} {ital 1996 The American Physical Society.}

  1. Simultaneous measurements of plasma parameters in the Saha Institute of Nuclear Physics Tokamak using a new low cost optoisolator

    NASA Astrophysics Data System (ADS)

    Ghosh, J.; Chattopadhyay, P. K.; Pal, R.; Bal, B.; Bhattacharya, P. S.

    2000-09-01

    In the Saha Institute of Nuclear Physics Tokamak (SINP-TOKAMAK), simultaneous measurement of signals from some diagnostics, like, electrostatic probes, etc., is not possible because pickup noises due to the formation of ground and other loops affect them quite severely. To avoid these loops and also to isolate some diagnostics from the ground, we developed a new type of optical isolator using a very low cost optical isolator chip (MC2TE made by Motorola) in a novel configuration. We continuously kept the light emitting diode on and used a feedback arrangement at the receiving side of the photoemitted signal for achieving good isolation for very low signals with reasonably high frequency response and good linearity. The method is highly cost effective in low budget tokamak experiments.

  2. Final Report for Nuclear Resonance Fluorescence Measurements of 239Pu above 2.5 MeV

    SciTech Connect

    Johnson, M S; McNabb, D P

    2009-01-07

    Nuclear Resonance Fluorescence measurements were performed at the free electron laser facility at UC Santa Barbara using a bremsstrahlung beam. Three endpoint energies were chosen for the bremsstrahlung to cover as much area above 2.5 MeV as possible. We were able to set an upper limit of NRF state strengths between 2.5 and 3.8 MeV at roughly 38(5) eV barns at the 4-sigma level and 9(2) eV barns at the 1-sigma level. Published results on states near 2.4 MeV indicate strengths about 10(2) eV barns. Details of the results are presented in this report.

  3. Laser spectroscopy of atoms in superfluid helium for the measurement of nuclear spins and electromagnetic moments of radioactive atoms

    NASA Astrophysics Data System (ADS)

    Fujita, T.; Furukawa, T.; Imamura, K.; Yang, X. F.; Hatakeyama, A.; Kobayashi, T.; Ueno, H.; Asahi, K.; Shimoda, T.; Matsuo, Y.

    2015-11-01

    A new laser spectroscopic method named "OROCHI (Optical RI-atom Observation in Condensed Helium as Ion catcher)" has been developed for deriving the nuclear spins and electromagnetic moments of low-yield exotic nuclei. In this method, we observe atomic Zeeman and hyperfine structures using laser-radio-frequency/microwave double-resonance spectroscopy. In our previous works, double-resonance spectroscopy was performed successfully with laser-sputtered stable atoms including non-alkali Au atoms as well as alkali Rb and Cs atoms. Following these works, measurements with 84-87Rb energetic ion beams were carried out in the RIKEN projectile fragment separator (RIPS). In this paper, we report the present status of OROCHI and discuss its feasibility, especially for low-yield nuclei such as unstable Au isotopes.

  4. Development of an energy discriminate CR-39(®) nuclear track etch dosimeter for Radon-220 gas measurements.

    PubMed

    Brown, J M C; Solomon, S; Tinker, R A

    2011-10-01

    An energy discriminate CR-39(®) nuclear track etch dosimeter for use in a (220)Rn and (222)Rn gas monitor has been developed and experimentally assessed. It utilises a thin film of Mylar(®) C to attenuate the alpha particle energies to allow only the damage tracks created by the 8.785 MeV alpha particles emitted from (212)Po of the (232)Th decay chain to be registered in the CR-39(®) plaque, allowing for the direct measurement of (220)Rn gas concentrations. The dosimeter was developed through a combination of experimental investigations and theoretical simulations using the Monte Carlo ion transport modelling program Stopping and Range of Ions in Materials (SRIM 2008). A film thickness of 54 μm has been shown to attenuate all alpha energies less then 7.7 MeV. PMID:20980083

  5. Basalt identification by interpreting nuclear and electrical well logging measurements using fuzzy technique (case study from southern Syria).

    PubMed

    Asfahani, J; Abdul Ghani, B; Ahmad, Z

    2015-11-01

    Fuzzy analysis technique is proposed in this research for interpreting the combination of nuclear and electrical well logging data, which include natural gamma ray, density and neutron-porosity, while the electrical well logging include long and short normal. The main objective of this work is to describe, characterize and establish the lithology of the large extended basaltic areas in southern Syria. Kodana well logging measurements have been used and interpreted for testing and applying the proposed technique. The established lithological cross section shows the distribution and the identification of four kinds of basalt, which are hard massive basalt, hard basalt, pyroclastic basalt and the alteration basalt products, clay. The fuzzy analysis technique is successfully applied on the Kodana well logging data, and can be therefore utilized as a powerful tool for interpreting huge well logging data with higher number of variables required for lithological estimations. PMID:26275816

  6. Feasibility study for the in vivo measurement of silicon and beryllium by nuclear techniques

    SciTech Connect

    Ettinger, K V; Morgan, W D; Miola, U; Vartsky, D; Ellis, K J; Wielopolski, L; Cohn, S H

    1980-01-01

    Experiments were performed to assess the feasibility of measuring silicon in vivo by means of the prompt neutron inelastic scattering reaction /sup 28/Si(n,n'..gamma..)/sup 28/Si. The optimum neutron energy in terms of counts per dose delivered to a liquid tissue-equivalent phantom was found to be in the range 5 to 8 MeV. By pulsing the neutron beam and counting only in the on period it was possible to substantially reduce the background both from thermal neutron interactions in the phantom and also from the fast interfering reaction /sup 31/P(n,..cap alpha..)/sup 28/Al. In final measurements with a realistic chest phantom no interferences from other prompt inelastic scattering reactions were observed. With one Ge(Li) detector of 19% relative efficiency, a detection limit of 0.6g silicon per rem was obtained. A system comprising six 25% efficient detectors would be capable of measuring normal lung silicon contents of about 0.1g. Berylliosis, a granulomatous lung disease, has been observed in persons with lung contents ranging from micrograms to tens of milligrams (a normal value is 1-2 ..mu..g).. For gamma photons between 1.665 MeV and 2.225 MeV (the beryllium and deuterium photonuclear thresholds respectively), the production of neutrons is a unique property of beryllium which might be exploited for analysis in vivo. Experiments with a Pb-filtered /sup 124/Sb source and an enriched /sup 10/BF/sub 3/ counter provided data from which it was projected that a 72-detector array might yield a detection limit of 3.4 mg Be for a lung dose of 2.5 rads. Possible methods for improving this result are discussed.

  7. Measurements of electrical conductivity for characterizing and monitoring nuclear waste repositories

    SciTech Connect

    Morrison, H.F.; Becker, A.; Lee, K.H.

    1986-11-01

    The detection of major fractures is one topic of this study but another equally important problem is to develop quantitative relationships between large scale resistivity and fracture systems in rock. There has been very little work done on this central issue. Empirical relations between resistivity and porosity have been derived on the basis of laboratory samples or from well logging, but there are no comparable 'laws' for rock masses with major fracture or joint patterns. Hydrologic models for such rocks have been recently been derived but the corresponding resistivity models have not been attempted. Resistivity due to fracture distributions with preferred orientation could be determined with such models, as could quantitative interpretation of changes as fracture aperature varies with load. This study is not only important for the assessment of a repository site, but has far ranging implications in reservoir studies for oil, gas, and geothermal resources. The electrical conductivity can be measured in two ways. Current can be injected into the ground through pairs of electrodes and corresponding voltage drops can be measured in the vicinity with other pairs of electrodes. The electrical conductivity can also be measured inductively. Instead of injecting current into the ground as described in the dc resistivity method, currents can be induced to flow by a changing magnetic field. In these inductive or electromagnetic (em) methods the interpretation depends both on transmitter-receiver geometry and frequency of operation. In principle the interpretation should be more definitive than with the dc resistivity methods. Rigorous confirmation of this statement in inhomogeneous media awaits the development of generalized inversion techniques for em methods.

  8. A system for the measurement of delayed neutrons and gammas from special nuclear materials

    SciTech Connect

    Andrews, M. T.; Corcoran, E. C.; Goorley, J. T.; Kelly, D. G.

    2014-11-27

    The delayed neutron counting (DNC) system at the Royal Military College of Canada has been upgraded to accommodate concurrent delayed neutron and gamma measurements. This delayed neutron and gamma counting (DNGC) system uses a SLOWPOKE-2 reactor to irradiate fissile materials before their transfer to a counting arrangement consisting of six ³He and one HPGe detector. The application of this system is demonstrated in an example where delayed neutron and gamma emissions are used in complement to examine ²³³U content and determine fissile mass with an average relative error and accuracy of -2.2 and 1.5 %, respectively.

  9. A system for the measurement of delayed neutrons and gammas from special nuclear materials

    DOE PAGESBeta

    Andrews, M. T.; Corcoran, E. C.; Goorley, J. T.; Kelly, D. G.

    2015-03-01

    The delayed neutron counting (DNC) system at the Royal Military College of Canada has been upgraded to accommodate concurrent delayed neutron and gamma measurements. This delayed neutron and gamma counting (DNGC) system uses a SLOWPOKE-2 reactor to irradiate fissile materials before their transfer to a counting arrangement consisting of six ³He and one HPGe detector. The application of this system is demonstrated in an example where delayed neutron and gamma emissions are used in complement to examine ²³³U content and determine fissile mass with an average relative error and accuracy of -2.2 and 1.5 %, respectively.

  10. Bedfast and floating ice lake talik properties measured using surface nuclear magnetic resonance on the North Slope, Alaska

    NASA Astrophysics Data System (ADS)

    Parsekian, A.; Jones, B. M.; Arp, C. D.; Creighton, A.; Daanen, R. P.; Gaedeke, A.; Bondurant, A.

    2015-12-01

    Lakes within permafrost regions have been identified as a source of carbon gas emissions, however the geometry of the thawed sediments and water content below these lakes that hold the carbon-rich source sediment remains difficult to measure. Surface nuclear magnetic resonance (NMR) is a geophysical measurement that is unambiguously sensitive to liquid water and therefore is well suited to discriminating between the sub-lake talik (thaw bulb) and surrounding permafrost. Here we report on talik thickness, water content, and pore scale properties observed using surface NMR in lakes located on the Arctic Coastal Plain of northern Alaska. The study lakes range in size from 0.5 km - 2 km in diameter. They have formed within a Pleistocene sand sheet deposit where permafrost extends 200 to 300 m below the surface. Lake depth ranges from less than 1 m (bedfast ice) to 5 m (floating ice); drained lake basins with no water or water ice were also measured for comparison. Floating ice lakes are interpreted to have a talik between 20 - 25 m below the surface. Bedfast ice lakes had either no measureable talik, a talik to < 20 m, or an isolated talik. Drained lake basins had either no measureable talik or an isolated talik. The presence of isolated taliks below some bedfast ice lakes and drained lake basins was a surprising result, suggesting that zones of unfrozen sediment may be present in the region even when the surface conditions suggest otherwise. These results of talik presence/absence and geometry bring new insight into permafrost-influenced lake subsurface hydrology and provide value data for validating hydrological modeling outputs. Our application of using surface NMR on Arctic Lakes will be extended to the region with numerous thermokarst lakes and drained lake basins north of Teshekpuk Lake next April.

  11. Nuclear magnetic resonance measurement of skeletal muscle: anisotrophy of the diffusion coefficient of the intracellular water.

    PubMed Central

    Cleveland, G G; Chang, D C; Hazlewood, C F; Rorschach, H E

    1976-01-01

    The anisotropy of the spin-diffusion coefficient Ds of water protons in skeletal muscle has been studied by pulsed NMR methods. The mid-portion of the tibialis anterior muscle of mature male rats was placed in a special sample holder by means of which the muscle fiber orientation theta relative to the diffusion direction could be varied over the range 0 degrees less than or equal to theta less than or equal to 90 degrees. The value of Ds(theta) was determined for theta = 0 degrees, 45 degrees, and 90 degrees. The measured anisotropy Ds(0)/Ds(90) was 1.39, and the value of Ds(0) was 1.39 X 10(-5) cm2/s. These results are interpreted within the framework of a model calculation in which the diffusion equation is solved for a regular hexagonal network similar to the actin-myosin filament network. The large anisotropy, and the large reduction in the value of Ds measured parallel to the filament axes lead to two major conclusions: (a) interpretations in which the reduction in Ds is ascribed to the effect of geometrical obstructions on the diffusion of "free" water are ruled out; and, (b) there is a large fraction of the cellular water associated with the proteins in such a way that its diffusion coefficient is substantially reduced. PMID:963204

  12. First Measurement of the {rho} Spectral Function in High-Energy Nuclear Collisions

    SciTech Connect

    Arnaldi, R.; Colla, A.; Cortese, P.; Ferretti, A.; Oppedisano, C.; Scomparin, E.; Averbeck, R.; Drees, A.; Banicz, K.; Specht, H.J.; Castor, J.; Devaux, A.; Fargeix, J.; Force, P.; Manso, F.; Chaurand, B.; Cicalo, C.; De Falco, A.; Floris, M.; Masoni, A.

    2006-04-28

    We report on a precision measurement of low-mass muon pairs in 158 AGeV indium-indium collisions at the CERN SPS. A significant excess of pairs is observed above the yield expected from neutral meson decays. The unprecedented sample size of 360 000 dimuons and the good mass resolution of about 2% allow us to isolate the excess by subtraction of the decay sources. The shape of the resulting mass spectrum is consistent with a dominant contribution from {pi}{sup +}{pi}{sup -}{yields}{rho}{yields}{mu}{sup +}{mu}{sup -} annihilation. The associated space-time averaged {rho} spectral function shows a strong broadening, but essentially no shift in mass. This may rule out theoretical models linking hadron masses directly to the chiral condensate.

  13. Development of a time-variable nuclear pulser for half life measurements

    SciTech Connect

    Zahn, Guilherme S.; Domienikan, Claudio; Carvalhaes, Roberto P. M.; Genezini, Frederico A.

    2013-05-06

    In this work a time-variable pulser system with an exponentially-decaying pulse frequency is presented, which was developed using the low-cost, open-source Arduino microcontroler plataform. In this system, the microcontroller produces a TTL signal in the selected rate and a pulse shaper board adjusts it to be entered in an amplifier as a conventional pulser signal; both the decay constant and the initial pulse rate can be adjusted using a user-friendly control software, and the pulse amplitude can be adjusted using a potentiometer in the pulse shaper board. The pulser was tested using several combinations of initial pulse rate and decay constant, and the results show that the system is stable and reliable, and is suitable to be used in half-life measurements.

  14. Considerations for Possible Light Impact of Spent Nuclear Fuel for Safeguards Measurements

    SciTech Connect

    Brian K. Castle; Kelly D. Ellis

    2012-09-01

    This effort is designed to be a preliminary study to determine the appropriateness of lightly contacting SNF with zirconium-based cladding, in wet storage, for the purpose of taking safeguards measurements. Contact will likely consist of an initial impact followed by a light tensile load on the exterior surface of the SNF cladding. In the past, concerns have been raised that contacting SNF cladding could result in a loss of long-term mechanical integrity due to crack initiation, uncontrolled crack propagation, and a mechanical exfoliation of the protective oxide layer. The mechanical integrity concerns are addressed with an analytic model that evaluates the threshold impact limits for degraded, but undamaged SNF cladding. Aqueous corrosion concerns, associated with exfoliation of the protective oxide layer, are addressed with a qualitative argument, focusing on the possible corrosion mechanisms of zirconium-based cladding.

  15. Progress and goals for INMM ASC N15 consensus standard ""Administrative practices for the determination and reporting of results of non-destructive assay measurements of nuclear material in situ for safeguards nuclear criticality safety and other purposes

    SciTech Connect

    Bracken, David S; Lamb, Frank W

    2009-01-01

    This paper will discuss the goals and progress to date on the development of INMM Accredited Standard Committee (ASC) N15 consensus standard Administrative Practices for the Determination and Reporting of Results of Non-Destructive Assay Measurements of Nuclear Material in situ for Safeguards, Nuclear Criticality Safety, and Other Purposes. This standard will define administrative practices in the areas of data generation and reporting of NDA assay of holdup deposits with consideration of the stakeholders of the reported results. These stakeholders may include nuclear material accounting and safeguards, nuclear criticality safety, waste management, health physics, facility characterization, authorization basis, radiation safety, and site licensing authorities. Stakeholder input will be solicited from interested parties and incorporated during the development of the document. Currently only one consensus standard exists that explicitly deals with NDA holdup measurements: ASTM C1455 Standard Test Method for Nondestructive Assay of Special Nuclear Material Holdup Using Gamma-Ray Spectroscopic Methods. The ASTM International standard emphasizes the activities involved in actually making measurements, and was developed by safeguards and NDA experts. This new INMM ASC N15 standard will complement the existing ASTM international standard. One of the largest driving factors for writing this new standard was the recent emphasis on in situ NDA measurements by the safeguards community due to the Defense Nuclear Facility Safety Board (DNFSB) recommendation 2007-1 on in situ NDA measurements. Specifically, DNFSB recommendation 2007-1 referenced the lack of programmatic requirements for accurate in situ measurements and the use of measurement results for compliance with safety based requirements. That being the case, this paper will also discuss the progress made on the Implementation Plan for Defense Nuclear Facilities Safety Board Recommendation 2007-1 Safety-Related In Situ

  16. Fissile and fertile nuclear material measurements using a new differential die-away self-interrogation technique

    SciTech Connect

    Menlove, Howard O; Tobin, Stephen J; Menlove, S H

    2008-01-01

    This paper presents a new technique for the measurement of fissile and fertile nuclear materials in spent fuel and plutonium laden materials such as mixed oxide (MOX) fuel. The technique, called differential die-away self-interrogation, is similar to traditional differential die-away analysis, but it does not require a pulsed neutron generator or pulsed beam accelerator, and it can measure the fertile mass in addition to the fissile mass. The new method uses the spontaneous fission neutrons from {sup 244}Cm in spent fuel and {sup 240}Pu effective neutrons in MOX as the 'pulsed' neutron source with an average of {approx} 2.7 neutrons per pulse. The time correlated neutrons from the spontaneous fission and the subsequent induced fissions are analyzed as a function of time to determine the spontaneous fission rate, the induced fast-neutron fissions, and the induced thermal-neutron fissions. The fissile mass is determined from the induced thermal-neutron fissions that are produced by reflected thermal neutrons that originated from the spontaneous fission reaction. The sensitivity of the fissile mass measurement is enhanced by the use of two measurements, with and without a cadmium liner between the sample and the hydrogenous moderator. The fertile mass is determined from the multiplicity analysis of the neutrons detected soon after the initial triggering neutron is detected. The method obtains good sensitivity by the optimal design of two different neutron die-away regions: a short die-away for the neutron detector region and a longer die-away for the sample interrogation region.

  17. Pore space characterization in carbonate rocks - Approach to combine nuclear magnetic resonance and elastic wave velocity measurements

    NASA Astrophysics Data System (ADS)

    Müller-Huber, Edith; Schön, Jürgen; Börner, Frank

    2016-04-01

    Pore space features influence petrophysical parameters such as porosity, permeability, elastic wave velocity or nuclear magnetic resonance (NMR). Therefore they are essential to describe the spatial distribution of petrophysical parameters in the subsurface, which is crucial for efficient reservoir characterization especially in carbonate rocks. While elastic wave velocity measurements respond to the properties of the solid rock matrix including pores or fractures, NMR measurements are sensitive to the distribution of pore-filling fluids controlled by rock properties such as the pore-surface-to-pore-volume ratio. Therefore a combination of both measurement principles helps to investigate carbonate pore space using complementary information. In this study, a workflow is presented that delivers a representative average semi-axis length of ellipsoidal pores in carbonate rocks based on the pore aspect ratio received from velocity interpretation and the pore-surface-to-pore-volume ratio Spor as input parameters combined with theoretical calculations for ellipsoidal inclusions. A novel method to calculate Spor from NMR data based on the ratio of capillary-bound to movable fluids and the thickness of the capillary-bound water film is used. To test the workflow, a comprehensive petrophysical database was compiled using micritic and oomoldic Lower Muschelkalk carbonates from Germany. The experimental data indicate that both mud-dominated and grain-dominated carbonates possess distinct ranges of petrophysical parameters. The agreement between the predicted and measured surface-to-volume ratio is satisfying for oomoldic and most micritic samples, while pyrite or significant sample heterogeneity may lead to deviations. Selected photo-micrographs and scanning electron microscope images support the validity of the estimated representative pore dimensions.

  18. Assaying of targets for nuclear measurements with a gridded ionization chamber

    NASA Astrophysics Data System (ADS)

    Budtz-Jørgensen, C.; Knitter, H. H.; Bortels, G.

    1985-06-01

    An ionization chamber with a Frisch grid is used to determine both the energy ( E) of the charge particles emitted from the sample positioned coplanar with the cathode, and the cosine of the emission angle (ϑ) with respect to the normal of the cathode Using the combined information on cosϑ and E, problems in particle counting due to sample absoprtion and scattering effect can be circumvented and sample source strengths are readily determined to an accurary of 0.3%. However, it is emphasized that the source strength can be determined from the particles emitted in a large solid angle close to 2τ sr, which means a considerable higher efficiency than for the conventional low geometry counting techniques. Moreover the present method, within reasonable limits is insensitive to source shape and thickness homogeneity. The technique will be illustrated by measurements of alpha particles and fission fragments emitted from a set of four vacuum evaporated UF 4, three electrodeposited and one suspension-sprayed 235U 3O 8 layers. The energy and angular distributions of alpha particles and of the heavy alpha recoils emitted from a self transferred 224Ra source will be discussed. The low energetic alpha recoils might be useful as probes for the investigation of ultrathin ( < 400 Å) layers.

  19. Nuclear emulsion measurements of the astronauts' radiation exposures on Skylab missions 2, 3, and 4

    NASA Technical Reports Server (NTRS)

    Schaefer, H. J.; Sullivan, J. J.

    1975-01-01

    On the Skylab missions, Ilford G.5 and K.2 emulsions were flown as part of passive dosimeter packs carried by the astronauts on their wrists. Due to the long mission times, latent image fading and track crowing imposed limitations on a quantitative track and grain count analysis. For Skylab 2, the complete proton energy spectrum was determined within reasonable error limits. A combined mission dose equivalent of 2,490 millirems from protons, tissue stars and neutrons was measured on Skylab 2. A stationary emulsion stack, kept in a film vault drawer on the same mission, displayed a highly structured directional distribution of the fluence of low-energy protons (enders) reflecting the local shield distribution. On the 59 and 84-day mission 3 and 4, G.5 emulsions had to be cut on the microtom to 5-7 microns for microscopic examination. Even so, the short track segments in such thin layers precluded a statistically reliable grain count analysis. However, the K.2 emulsions still allowed accurate proton ender counts without special provisions.

  20. Critical-Point Boundary for the Nuclear Quantum Phase Transition Near A=100 from Mass Measurements of {sup 96,97}Kr

    SciTech Connect

    Naimi, S.; Audi, G.; Lunney, D.; Beck, D.; Herfurth, F.; Blaum, K.; Boehm, Ch.; Borgmann, Ch.; George, S.; Kowalska, M.; Kreim, S.; Breitenfeldt, M.; Rosenbusch, M.; Schweikhard, L.; Herlert, A.; Neidherr, D.; Schwarz, S.; Zuber, K.

    2010-07-16

    Mass measurements of {sup 96,97}Kr using the ISOLTRAP Penning-trap spectrometer at CERN-ISOLDE are reported, extending the mass surface beyond N=60 for Z=36. These new results show behavior in sharp contrast to the heavier neighbors where a sudden and intense deformation is present. We interpret this as the establishment of a nuclear quantum phase transition critical-point boundary. The new masses confirm findings from nuclear mean-square charge-radius measurements up to N=60 but are at variance with conclusions from recent gamma-ray spectroscopy.