Science.gov

Sample records for alice time-of-flight detector

  1. Particle identification with the ALICE Time-Of-Flight detector at the LHC

    NASA Astrophysics Data System (ADS)

    Alici, A.

    2014-12-01

    High performance Particle Identification system (PID) is a distinguishing characteristic of the ALICE experiment at the CERN Large Hadron Collider (LHC). Charged particles in the intermediate momentum range are identified in ALICE by the Time-Of-Flight (TOF) detector. The TOF exploits the Multi-gap Resistive Plate Chamber (MRPC) technology, capable of an intrinsic time resolution at the level of few tens of ps with an overall efficiency close to 100% and a large operation plateau. The full system is made of 1593 MRPC chambers with a total area of 141 m2, covering the pseudorapidity interval [-0.9,+0.9] and the full azimuthal angle. The ALICE TOF system has shown very stable operation during the first 3 years of collisions at the LHC. In this paper a summary of the system performance as well as main results with data from collisions will be reported.

  2. The MRPC-based ALICE time-of-flight detector: Status andperformance

    NASA Astrophysics Data System (ADS)

    Alici, A.; ALICE Collaboration

    2013-04-01

    The large time-of-flight (TOF) array is one of the main detectors devoted to charged hadron identification in the mid-rapidity region of the ALICE experiment at the LHC. It allows separation among pions, kaons and protons up to a few GeV/c, covering the full azimuthal angle and -0.9<η<0.9. The TOF exploits the innovative MRPC technology capable of an intrinsic time resolution better than 50 ps with an efficiency close to 100% and a large operational plateau; the full array consists of 1593 MRPCs covering a cylindrical surface of 141 m2. The TOF detector has been efficiently taking data since the first pp collisions recorded in ALICE in December 2009. In this report, the status of the TOF detector and the performance achieved for both pp and Pb-Pb collisions aredescribed.

  3. Status and performance of the ALICE MRPC-based Time-Of-Flight detector

    NASA Astrophysics Data System (ADS)

    Alici, A.

    2012-10-01

    ALICE is the dedicated heavy-ion experiment at the CERN LHC. One of the main detectors devoted to charged hadron identification in the ALICE central barrel is a large Time-Of-Flight (TOF) array; it allows separation among pions, kaons and protons up to a few GeV/c, covering the full azimuthal angle and -0.9 < η < 0.9. The very good performance required for such a system has been achieved by means of the Multigap Resistive Plate Chamber (MRPC) whose intrinsic time resolution is better than 50 ps with an overall efficiency close to 100% and a large operational plateau; the full array consists of 1593 MRPCs covering a cylindrical surface of 141 m2. In this report, the status of the TOF detector and the performance achieved during the 2010 and 2011 data taking periods are reported together with selected physics results obtained with pp and Pb-Pb collisions.

  4. The CDF Time of Flight Detector

    SciTech Connect

    S. Cabrera et al.

    2004-01-06

    A new Time of Flight (TOF) detector based on scintillator bars with fine-mesh photomultipliers at both ends has been in operation since 2001 in the CDF experiment. With a design resolution of 100 ps, the TOF can provide separation between K{sup +-} and {pi}{sup +-} in p{bar p} collisions at the 2{omega} level for low momentum, which enhances b flavor tagging capabilities. Because of its very fast response, the TOF is an excellent triggering device, and it is used to trigger on highly ionizing particles, multiple minimum ionizing particles and cosmic rays. Particle identification is achieved by comparing the time-of-flight of the particle measured by the TOF to the time expected for a given mass hypothesis. In order to obtain the resolution necessary for particle ID, optimal calibrations are critical. This paper describes the TOF detector, its calibration procedure, the achieved resolution, the long term operation performances and some of the first results from data analysis using this detector.

  5. The TORCH time-of-flight detector

    NASA Astrophysics Data System (ADS)

    Harnew, N.; Brook, N.; Castillo García, L.; Cussans, D.; Föhl, K.; Forty, R.; Frei, C.; Gao, R.; Gys, T.; Piedigrossi, D.; Rademacker, J.; Ros Garcia, A.; van Dijk, M.

    2016-07-01

    The TORCH time-of-flight detector is being developed to provide particle identification between 2 and 10 GeV/c momentum over a flight distance of 10 m. TORCH is designed for large-area coverage, up to 30 m2, and has a DIRC-like construction. The goal is to achieve a 15 ps time-of-flight resolution per incident particle by combining arrival times from multiple Cherenkov photons produced within quartz radiator plates of 10 mm thickness. A four-year R&D programme is underway with an industrial partner (Photek, UK) to produce 53×53 mm2 Micro-Channel Plate (MCP) detectors for the TORCH application. The MCP-PMT will provide a timing accuracy of 40 ps per photon and it will have a lifetime of up to at least 5 Ccm-2 of integrated anode charge by utilizing an Atomic Layer Deposition (ALD) coating. The MCP will be read out using charge division with customised electronics incorporating the NINO chipset. Laboratory results on prototype MCPs are presented. The construction of a prototype TORCH module and its simulated performance are also described.

  6. Recipes for high resolution time-of-flight detectors

    SciTech Connect

    Anz, S.J. |; Felter, T.E.; Hess, B.V.; Daley, R.S.; Roberts, M.L.; Williams, R.S.

    1995-01-01

    The authors discuss the dynamics, construction, implementation and benefits of a time-of-flight (TOF) detector with count rates an order of magnitude higher and resolution three to four times better than that obtainable with a surface barrier detector. The propose use of design criteria for a time-of-flight detector is outlined, and the determination of a TOF detector`s total relative timing error and how this value determines the mass resolution are illustrated using a graphical analysis. They present simulation and experimental examples employing light ions and discuss advantages and pitfalls of medium-energy heavy ion TOF spectrometry.

  7. Beam Test of a Time-of-Flight Detector Prototype

    SciTech Connect

    Va'vra, J.; Leith, D.W.G.S.; Ratcliff, B.; Ramberg, E.; Albrow, M.; Ronzhin, A.; Ertley, C.; Natoli, T.; May, E.; Byrum, K.; /Argonne

    2009-04-01

    We report on results of a Time-of-Flight, TOF, counter prototype in beam tests at SLAC and Fermilab. Using two identical 64-pixel Photonis Microchannel Plate Photomultipliers, MCP-PMTs, to provide start and stop signals, each having a 1 cm-long quartz Cherenkov radiator, we have achieved a timing resolution of {sigma}{sub Single{_}detector} {approx} 14 ps.

  8. The Time Of Flight Scintillators For The Blast Detector

    NASA Astrophysics Data System (ADS)

    Sindile, A. T.

    2001-10-01

    The testing procedures for the time-of-flight scintillators of the Bates Large Acceptance Spectrometer Toroid are presented. The manufacturing process is described and the results for the time resolution and efficiency tests are shown, with details of the hardware and sofware used.

  9. The ALICE Forward Multiplicity Detector

    NASA Astrophysics Data System (ADS)

    Christensen, Christian Holm; Gaardhøje, Jens Jørgen; Gulbrandsen, Kristján; Nielsen, Børge Svane; Søgaard, Carsten

    The ALICE Forward Multiplicity Detector (FMD) is a silicon strip detector with 51,200 strips arranged in 5 rings, covering the range -3.4 < η < 5.1. It is placed around the beam pipe at small angles to extend the charged particle acceptance of ALICE into the forward regions, not covered by the central barrel detectors.

  10. Analysis of inelastic neutron scattering spectra from a time-of-flight spectrometer with filter detector

    SciTech Connect

    Vorderwisch, P.; Mezei, F.; Eckert, J.; Goldstone, J.A.

    1986-01-01

    Inelastic neutron scattering spectra obtained from time-of-flight spectrometers with filter detector suffer in energy resolution from a long time-of-flight tail in the filter response function. A mathematical method is described which removes this tail in measured spectra. The energy resolution can thereby be adapted for each part of the spectrum. Applications of the method to data taken at the LANSCE pulsed spallation source are presented.

  11. Comparison of detector materials for time-of-flight positron tomography

    SciTech Connect

    Derenzo, S.E.

    1982-06-01

    Knowledge of detection efficiency and timing resolution is essential when comparing detector materials for time-of-flight positron tomography. We present results of Monte Carlo calculations of the detection efficiency of plastic, lead loaded plastic, NaI(T1), liquid xenon, bismuth germanate (BGO), CsF, BaF/sub 2/, Ge, and HgI/sub 2/ for 511 keV photons. We also use recently published values of timing resolution for these detector materials to tabulate the quantity (efficiency)/sup 2//(time resolution) which is a measure of the relative sensitivity for time of flight positron tomography.

  12. Microsphere plate detectors used with a compact Mott polarimeter for time-of-flight studies

    SciTech Connect

    Snell, G.; Viefhaus, J.; Dunning, F. B.; Berrah, N.

    2000-06-01

    A compact retarding-potential Mott polarimeter combined with microsphere plates (MSP) as electron detectors was built to perform spin-resolved time-of-flight electron spectroscopy. The comparison of the performance of MSP and channeltron detectors shows that the MSP detector has a better time resolution but a lower efficiency. The overall time resolution of the system was determined to be 350 ps using synchrotron radiation pulses. (c) 2000 American Institute of Physics.

  13. The ALICE forward multiplicity detector

    NASA Astrophysics Data System (ADS)

    Gulbrandsen, K.; Bearden, I.; Bertelsen, P. H.; Christensen, C. H.; Gaardhøje, J. J.; Nielsen, B. S.; Alice Collaboration

    2006-08-01

    The ALICE experiment is designed to study the properties of hadron and nucleus collisions in a new energy regime at the Large Hadron Collider at CERN. A fundamental observable in such collisions is the multiplicity distribution of charged particles. A forward multiplicity detector has been designed to extend the charged particle multiplicity coverage of the ALICE experiment to pseudorapidities of -3.4<η<-1.7 and 1.7<η<5.0. This detector consists of five rings, each containing 10240 Si strips, divided into sectors comprised of Si sensors bonded and glued to hybrid PC boards equipped with radiation hard preamplifiers. The output of these preamplifiers is multiplexed into custom-made fast ADC chips located directly behind the Si sensors on the detector frame. These ADCs are read out, via optical fibers, to a data acquisition farm of commodity PCs. The design and characteristics of the ALICE Forward Multiplicity Detector will be discussed.

  14. Testing a new NIF neutron time-of-flight detector with a bibenzyl scintillator on OMEGA

    SciTech Connect

    Glebov, V. Yu.; Forrest, C.; Knauer, J. P.; Pruyne, A.; Romanofsky, M.; Sangster, T. C.; Shoup, M. J. III; Stoeckl, C.; Caggiano, J. A.; Carman, M. L.; Clancy, T. J.; Hatarik, R.; McNaney, J.; Zaitseva, N. P.

    2012-10-15

    A new neutron time-of-flight (nTOF) detector with a bibenzyl crystal as a scintillator has been designed and manufactured for the National Ignition Facility (NIF). This detector will replace a nTOF20-Spec detector with an oxygenated xylene scintillator currently operational on the NIF to improve the areal-density measurements. In addition to areal density, the bibenzyl detector will measure the D-D and D-T neutron yield and the ion temperature of indirect- and direct-drive-implosion experiments. The design of the bibenzyl detector and results of tests on the OMEGA Laser System are presented.

  15. Testing a new NIF neutron time-of-flight detector with a bibenzyl scintillator on OMEGAa)

    NASA Astrophysics Data System (ADS)

    Glebov, V. Yu.; Forrest, C.; Knauer, J. P.; Pruyne, A.; Romanofsky, M.; Sangster, T. C.; Shoup, M. J.; Stoeckl, C.; Caggiano, J. A.; Carman, M. L.; Clancy, T. J.; Hatarik, R.; McNaney, J.; Zaitseva, N. P.

    2012-10-01

    A new neutron time-of-flight (nTOF) detector with a bibenzyl crystal as a scintillator has been designed and manufactured for the National Ignition Facility (NIF). This detector will replace a nTOF20-Spec detector with an oxygenated xylene scintillator currently operational on the NIF to improve the areal-density measurements. In addition to areal density, the bibenzyl detector will measure the D-D and D-T neutron yield and the ion temperature of indirect- and direct-drive-implosion experiments. The design of the bibenzyl detector and results of tests on the OMEGA Laser System are presented.

  16. Testing a new NIF neutron time-of-flight detector with a bibenzyl scintillator on OMEGA.

    PubMed

    Glebov, V Yu; Forrest, C; Knauer, J P; Pruyne, A; Romanofsky, M; Sangster, T C; Shoup, M J; Stoeckl, C; Caggiano, J A; Carman, M L; Clancy, T J; Hatarik, R; McNaney, J; Zaitseva, N P

    2012-10-01

    A new neutron time-of-flight (nTOF) detector with a bibenzyl crystal as a scintillator has been designed and manufactured for the National Ignition Facility (NIF). This detector will replace a nTOF20-Spec detector with an oxygenated xylene scintillator currently operational on the NIF to improve the areal-density measurements. In addition to areal density, the bibenzyl detector will measure the D-D and D-T neutron yield and the ion temperature of indirect- and direct-drive-implosion experiments. The design of the bibenzyl detector and results of tests on the OMEGA Laser System are presented. PMID:23126836

  17. The ALICE Pixel Detector

    NASA Astrophysics Data System (ADS)

    Mercado-Perez, Jorge

    2002-07-01

    The present document is a brief summary of the performed activities during the 2001 Summer Student Programme at CERN under the Scientific Summer at Foreign Laboratories Program organized by the Particles and Fields Division of the Mexican Physical Society (Sociedad Mexicana de Fisica). In this case, the activities were related with the ALICE Pixel Group of the EP-AIT Division, under the supervision of Jeroen van Hunen, research fellow in this group. First, I give an introduction and overview to the ALICE experiment; followed by a description of wafer probing. A brief summary of the test beam that we had from July 13th to July 25th is given as well.

  18. Detector response in time-of-flight mass spectrometry at high pulse repetition frequencies

    NASA Technical Reports Server (NTRS)

    Gulcicek, Erol E.; Boyle, James G.

    1993-01-01

    Dead time effects in chevron configured dual microchannel plates (MCPs) are investigated. Response times are determined experimentally for one chevron-configured dual MCP-type detector and two discrete dynode-type electron multipliers with 16 and 23 resistively divided stages. All of these detectors are found to be suitable for time-of-flight mass spectrometry (TOF MS), yielding 3-6-ns (FWHM) response times triggered on a single ion pulse. It is concluded that, unless there are viable solutions to overcome dead time disadvantages for continuous dynode detectors, suitable discrete dynode detectors for TOF MS appear to have a significant advantage for high repetition rate operation.

  19. Calibration of time of flight detectors using laser-driven neutron source

    SciTech Connect

    Mirfayzi, S. R.; Kar, S. Ahmed, H.; Green, A.; Alejo, A.; Jung, D.; Krygier, A. G.; Freeman, R. R.; Clarke, R.; Fuchs, J.; Vassura, L.; Kleinschmidt, A.; Roth, M.; Morrison, J. T.; Najmudin, Z.; Nakamura, H.; Norreys, P.; Oliver, M.; Zepf, M.; Borghesi, M.

    2015-07-15

    Calibration of three scintillators (EJ232Q, BC422Q, and EJ410) in a time-of-flight arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub-MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors is shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

  20. Calibration of time of flight detectors using laser-driven neutron source.

    PubMed

    Mirfayzi, S R; Kar, S; Ahmed, H; Krygier, A G; Green, A; Alejo, A; Clarke, R; Freeman, R R; Fuchs, J; Jung, D; Kleinschmidt, A; Morrison, J T; Najmudin, Z; Nakamura, H; Norreys, P; Oliver, M; Roth, M; Vassura, L; Zepf, M; Borghesi, M

    2015-07-01

    Calibration of three scintillators (EJ232Q, BC422Q, and EJ410) in a time-of-flight arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub-MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors is shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil. PMID:26233373

  1. ALICE detector in construction phase

    NASA Astrophysics Data System (ADS)

    Peryt, Wiktor S.

    2005-09-01

    ALICE1 collaboration, which prepares one of the biggest physics experiments in the history, came into production phase of its detector. The experiment will start at LHC2 at CERN in 2007/2008. In the meantime about 1000 people from ~70 institutions are involved in this enterprise. ALICE detector consists of many sub-detectors, designed and manufactured in many laboratories and commercial firms, located mainly in Europe, but also in U.S., India, China and Korea. To assure appropriate working environment for such a specific task, strictly related to tests of particular components, measurements and assembly procedures Detector Construction Database system has been designed and implemented at CERN and at some labs involved in these activities. In this paper special attention is paid to this topic not only due to fact of innovative approach to the problem. Another reason is the group of young computer scientists (mainly students) from the Warsaw University of Technology, leaded by the author, has designed and developed the system for the whole experiment3. Another very interesting subject is the Data Acquisition System which has to fulfill very hard requirements concerning speed and high bandwidth. Required technical performance is achieved thanks to using PCI bus (usually in previous high energy physics experiments VME standard has been used) and optical links. Very general overview of the whole detector and physics goals of ALICE experiment will also be given.

  2. A position sensitive time of flight detector for heavy ion ERD

    NASA Astrophysics Data System (ADS)

    Eschbaumer, S.; Bergmaier, A.; Dollinger, G.

    2016-03-01

    A new 2D position sensitive time of flight detector for heavy ion ERD has been developed. The detector features separate time and position measurement in a straight geometry. An electrostatic lens focuses the secondary electrons ejected from a carbon foil onto a channel plate stack maintaining the position information despite the electron momentum distribution. For position readout a 2D Backgammon anode is used. A position resolution of <0.6 mm (FWHM) and a time resolution of 96 ps (FWHM) is demonstrated.

  3. A new neutron time-of-flight detector for fuel-areal-density measurements on OMEGA

    NASA Astrophysics Data System (ADS)

    Glebov, V. Yu.; Forrest, C. J.; Marshall, K. L.; Romanofsky, M.; Sangster, T. C.; Shoup, M. J.; Stoeckl, C.

    2014-11-01

    A new neutron time-of-flight (nTOF) detector for fuel-areal-density measurements in cryogenic DT implosions was installed on the OMEGA Laser System. The nTOF detector has a cylindrical thin-wall, stainless-steel, 8-in.-diam, 4-in.-thick cavity filled with an oxygenated liquid xylene scintillator. Four gated photomultiplier tubes (PMTs) with different gains are used to measure primary DT and D2 neutrons, down-scattered neutrons in nT and nD kinematic edge regions, and to study tertiary neutrons in the same detector. The nTOF detector is located 13.4 m from target chamber center in a well-collimated line of sight. The design details of the nTOF detector, PMT optimization, and test results on OMEGA will be presented.

  4. A new neutron time-of-flight detector for fuel-areal-density measurements on OMEGA

    SciTech Connect

    Glebov, V. Yu. Forrest, C. J.; Marshall, K. L.; Romanofsky, M.; Sangster, T. C.; Shoup, M. J.; Stoeckl, C.

    2014-11-15

    A new neutron time-of-flight (nTOF) detector for fuel-areal-density measurements in cryogenic DT implosions was installed on the OMEGA Laser System. The nTOF detector has a cylindrical thin-wall, stainless-steel, 8-in.-diam, 4-in.-thick cavity filled with an oxygenated liquid xylene scintillator. Four gated photomultiplier tubes (PMTs) with different gains are used to measure primary DT and D{sub 2} neutrons, down-scattered neutrons in nT and nD kinematic edge regions, and to study tertiary neutrons in the same detector. The nTOF detector is located 13.4 m from target chamber center in a well-collimated line of sight. The design details of the nTOF detector, PMT optimization, and test results on OMEGA will be presented.

  5. A new neutron time-of-flight detector for fuel-areal-density measurements on OMEGA.

    PubMed

    Glebov, V Yu; Forrest, C J; Marshall, K L; Romanofsky, M; Sangster, T C; Shoup, M J; Stoeckl, C

    2014-11-01

    A new neutron time-of-flight (nTOF) detector for fuel-areal-density measurements in cryogenic DT implosions was installed on the OMEGA Laser System. The nTOF detector has a cylindrical thin-wall, stainless-steel, 8-in.-diam, 4-in.-thick cavity filled with an oxygenated liquid xylene scintillator. Four gated photomultiplier tubes (PMTs) with different gains are used to measure primary DT and D2 neutrons, down-scattered neutrons in nT and nD kinematic edge regions, and to study tertiary neutrons in the same detector. The nTOF detector is located 13.4 m from target chamber center in a well-collimated line of sight. The design details of the nTOF detector, PMT optimization, and test results on OMEGA will be presented. PMID:25430281

  6. Design and performance of a high spatial resolution, time-of-flight PET detector

    PubMed Central

    Krishnamoorthy, Srilalan; LeGeyt, Benjamin; Werner, Matthew E.; Kaul, Madhuri; Newcomer, F. M.; Karp, Joel S.; Surti, Suleman

    2014-01-01

    This paper describes the design and performance of a high spatial resolution PET detector with time-of-flight capabilities. With an emphasis on high spatial resolution and sensitivity, we initially evaluated the performance of several 1.5 × 1.5 and 2.0 × 2.0 mm2 and 12–15 mm long LYSO crystals read out by several appropriately sized PMTs. Experiments to evaluate the impact of reflector on detector performance were performed and the final detector consisted of a 32 × 32 array of 1.5 × 1.5 × 15 mm3 LYSO crystals packed with a diffuse reflector and read out by a single Hamamatsu 64 channel multi-anode PMT. Such a design made it compact, modular and offered a cost-effective solution to obtaining excellent energy and timing resolution. To minimize the number of readout signals, a compact front-end readout electronics that summed anode signals along each of the orthogonal directions was also developed. Experimental evaluation of detector performance demonstrates clear discrimination of the crystals within the detector. An average energy resolution (FWHM) of 12.7 ± 2.6% and average coincidence timing resolution (FWHM) of 348 ps was measured, demonstrating suitability for use in the development of a high spatial resolution time-of-flight scanner for dedicated breast PET imaging. PMID:25246711

  7. The CDFII Time-of-Flight detector and impact on beauty flavor tagging

    NASA Astrophysics Data System (ADS)

    Giagu, Stefano

    2003-06-01

    The new CDFII detector incorporates a Time-of-Flight detector (TOF), employing plastic scintillator bars and fine-mesh photomultipliers. Since August 2001 the TOF system has been fully instrumented and integrated into the CDFII data acquisition system. With a design goal of 100 ps resolution the TOF system will provide at least two standard deviations separation between K± and π± for momenta p < 1.6 GeV/ c, complementing low momentum particle identification by means of the specific ionization energy loss measured in the drift chamber. We describe the design of the TOF detector and discuss the current status of its calibration and initial performances. Finally we review the expected impact of the TOF detector in the flavor tagging of neutral Bs0 meson.

  8. Time-of-flight calibration of a 6Li glass epithermal neutron detector

    PubMed

    Livingston; Saleh; Block; Brand

    2000-10-01

    The curing of Portland cement concrete involves the conversion of water from a free to a bound state. The process can be monitored nondestructively by measuring the shift in the neutron energy spectrum in the epithermal range (0.025-1 eV). A tuned array of 6Li glass detectors has been constructed with varying efficiencies over the epithermal energy range. To determine the efficiency of each detector as a function of neutron energy, it is necessary to calibrate it against a reference neutron spectrum. This was accomplished using a time-of-flight approach with a pulsed neutron beam produced at the Gaerttner LINAC Laboratory at Rensselaer Polytechnic Institute. With a neutron flight path of 25 m it was possible to determine the neutron detector efficiencies to an energy resolution of 11 microeV. The data showed good agreement with the detector design calculations. PMID:11003519

  9. A silicon photomultiplier readout for time of flight neutron spectroscopy with {gamma}-ray detectors

    SciTech Connect

    Pietropaolo, A.; Gorini, G.; Festa, G.; Andreani, C.; De Pascale, M. P.; Reali, E.; Grazzi, F.; Schooneveld, E. M.

    2009-09-15

    The silicon photomultiplier (SiPM) is a recently developed photosensor used in particle physics, e.g., for detection of minimum ionizing particles and/or Cherenkov radiation. Its performance is comparable to that of photomultiplier tubes, but with advantages in terms of reduced volume and magnetic field insensitivity. In the present study, the performance of a gamma ray detector made of an yttrium aluminum perovskite scintillation crystal and a SiPM-based readout is assessed for use in time of flight neutron spectroscopy. Measurements performed at the ISIS pulsed neutron source demonstrate the feasibility of {gamma}-detection based on the new device.

  10. TORCH - Cherenkov and Time-of-Flight PID Detector for the LHCb Upgrade at CERN

    NASA Astrophysics Data System (ADS)

    Föhl, K.; Brook, N.; Castillo García, L.; Conneely, T.; Cussans, D.; Forty, R.; Frei, C.; Gao, R.; Gys, T.; Harnew, N.; Milnes, J.; Piedigrossi, D.; Rademacker, J.; Ros Garcì a, A.; van Dijk, M.

    2016-05-01

    TORCH is a large-area precision time-of-flight detector, based on Cherenkov light production and propagation in a quartz radiator plate, which is read out at its edges. TORCH is proposed for the LHCb experiment at CERN to provide positive particle identification for kaons, and is currently in the Research-and-Development phase. A brief overview of the micro-channel plate photon sensor development, the custom-made electronics, and an introduction to the current test beam activities is given. Optical readout solutions are presented for the potential use of BaBar DIRC bar boxes as part of the TORCH configuration in LHCb.

  11. The CDFII time-of-flight detector and impact on beauty flavor tagging

    SciTech Connect

    C. Grozis et al.

    2002-12-03

    Following the successful RunI from 1992 to 1996, the CDF detector has undergone a major upgrade [1] for the RunII which begun in March 2001. The approval for the addition of a Time-of-Flight detector was granted in January 1999. The installation of the TOF detector was completed in August 2001 and its data has been included in the CDFII readout since then. The primary physics motivation for TOF is to complement and enhance the particle identification capability provided by the central drift chamber (COT) since it distinguishes K{sup {+-}} and {pi}{sup {+-}} in the momentum region of their cross-over in dE=dX. With an expected time-of-flight resolution of 100 ps, the TOF system will be capable of identifying charged kaons from pions by their flight time difference with at least two standard deviation separation up to kaon momenta of 1.6 GeV/c. Such an addition results in an enhancement of the b flavor identification power, crucial to improve the statistical precision in CP violation and B{sub s} mixing measurements.

  12. Central Time-Of-Flight detector for CLAS12 Hall-B upgrade

    NASA Astrophysics Data System (ADS)

    Baturin, Vitaly

    2013-10-01

    The time-of-flight system for CLAS12 at Hall-B of the Thomas Jefferson National Accelerator Facility will have a refurbished forward-angle detector and a new barrel scintillation detector for the time-of-flight measurements in the central region inside the superconducting 5 T-solenoid. The 92 cm-long barrel with the inner diameter 50 cm is formed by 48 scintillators of a trapezoidal cross-section about 3×3 cm2. Each scintillator is readout by R2083 PMTs from both upstream and downstream sides via a novel focusing light guides 1 m- and 1.6 m-long respectively. Both PMTs of each counter are enclosed into a novel dynamical magnetic shield that allows PMT performance at 1000 G-solenoid fringe fields. The expected timing resolution of this detector is 60 ps that allows pion-kaon and pion-proton separation at 3.3. sigma level up to 0.64 GeV/c and 1.25 GeV/c respectively. Thomas Jefferson National Accelerator Facility. Done...processed 770 records...10:56:06

  13. A Novel Time of Flight Detector for the Pioneering High Energy Nuclear Interaction eXperiment

    NASA Astrophysics Data System (ADS)

    Dix, Richard; Drummond, Kirk; Powell, William; Chiu, Mickey

    2010-11-01

    Time-of Flight (TOF) detectors allow one to identify particles created in collider experiments. The Pioneering High Energy Nuclear Interaction eXperiment (PHENIX) at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory is proposing new forward timing detectors to measure the TOF with a 10 picosecond (ps) timing resolution. A prototype of the detector electronics system was tested by using Cherenkov signals from cosmic rays and translating them into digital signals. Each signal was split and delivered to two analog-to-digital-converters (ADCs). C++ and ROOT were used to write programs to compare voltage readings reported by the two ADC channels and determine the time difference between them, which was 76 ps. Using new ADCs, which run 17 times faster, the timing resolution will be 5 ps. This will allow PHENIX to probe the meson-baryon anomaly at intermediate, transverse momentum by making detailed measurements in a psuedorapidity region which has not been well measured.

  14. A fault location system for a time of flight detector array

    NASA Astrophysics Data System (ADS)

    Hall, D. E.; Agogino, A.; Greiman, W. H.; Johnston, W. F.; Olson, D.; Paasch, R.; Padgaonkar, A.; Robertson, D. W.

    1989-12-01

    We describe a fault location system currently under development at Lawrence Berkeley Laboratory for the HISS Time of Flight Wall. The system identifies malfunctioning components by monitoring the detector output channels. For single component failures, a fast simple, lookup procedure reduces the number of suspected components to at most three out of 2500 possible. The system remembers failed components, so that it continues to locate new failures even when several components are in a failed state. The system can also handle partial component failures such as might be caused by the partial failure of a large power supply module. The approach shows promise for more complex detector systems. Plans for a rule-based, "expert system", analysis to further narrow the list of suspected components are presented.

  15. An improvement of isochronous mass spectrometry: Velocity measurements using two time-of-flight detectors

    NASA Astrophysics Data System (ADS)

    Shuai, P.; Xu, X.; Zhang, Y. H.; Xu, H. S.; Litvinov, Yu. A.; Wang, M.; Tu, X. L.; Blaum, K.; Zhou, X. H.; Yuan, Y. J.; Yan, X. L.; Chen, X. C.; Chen, R. J.; Fu, C. Y.; Ge, Z.; Huang, W. J.; Xing, Y. M.; Zeng, Q.

    2016-06-01

    Isochronous mass spectrometry (IMS) in storage rings is a powerful tool for mass measurements of exotic nuclei with very short half-lives down to several tens of microseconds, using a multicomponent secondary beam separated in-flight without cooling. However, the inevitable momentum spread of secondary ions limits the precision of nuclear masses determined by using IMS. Therefore, the momentum measurement in addition to the revolution period of stored ions is crucial to reduce the influence of the momentum spread on the standard deviation of the revolution period, which would lead to a much improved mass resolving power of IMS. One of the proposals to upgrade IMS is that the velocity of secondary ions could be directly measured by using two time-of-flight (double TOF) detectors installed in a straight section of a storage ring. In this paper, we outline the principle of IMS with double TOF detectors and the method to correct the momentum spread of stored ions.

  16. Photo-Detectors for Time of Flight Positron Emission Tomography (ToF-PET)

    PubMed Central

    Spanoudaki, Virginia Ch.; Levin⋆, Craig S.

    2010-01-01

    We present the most recent advances in photo-detector design employed in time of flight positron emission tomography (ToF-PET). PET is a molecular imaging modality that collects pairs of coincident (temporally correlated) annihilation photons emitted from the patient body. The annihilation photon detector typically comprises a scintillation crystal coupled to a fast photo-detector. ToF information provides better localization of the annihilation event along the line formed by each detector pair, resulting in an overall improvement in signal to noise ratio (SNR) of the reconstructed image. Apart from the demand for high luminosity and fast decay time of the scintillation crystal, proper design and selection of the photo-detector and methods for arrival time pick-off are a prerequisite for achieving excellent time resolution required for ToF-PET. We review the two types of photo-detectors used in ToF-PET: photomultiplier tubes (PMTs) and silicon photo-multipliers (SiPMs) with a special focus on SiPMs. PMID:22163482

  17. Laser Testing for the ATLAS Forward Proton Time of Flight Detector

    NASA Astrophysics Data System (ADS)

    Howley, Ian; Brandt, Andrew

    2009-10-01

    In 10 trillionths of a second light travels 3mm. Our group at UTA is currently developing the most precise time of flight (TOF) detector ever deployed in a collider experiment, with a resolution on this 10 picosecond scale. In conjunction with several other universities we have proposed to install a fast timing system as part of a proton detector upgrade to the main ATLAS detector at the Large Hadron Collider (LHC) . Precise measurement of the timing of proton tracks will allow rejection of background to the physics processes of interest, which include the elusive Higgs Boson. Laser based tests at UTA allow us to measure the response of our detectors downstream electronics including constant fraction discriminators, amplifiers and most importantly the microchannel plate photomultiplier tubes, which are at the heart of this fast-timing system. By isolating the individual components of the detector in this fashion, we can fully characterize each device's response. My research is part of the ongoing data analysis using the CERN analysis package ROOT. By closely examining the pulse height, time difference distributions, and transit time spread (TTS) we are be able to understand the performance of the detectors and electronics in laser and beam tests to better prepare ourselves for future test beams and eventually full scale installation and operation. I will present the latest performance test results from data I have analyzed.

  18. Laser Testing for the ATLAS Forward Proton Time of Flight Detector

    NASA Astrophysics Data System (ADS)

    Howley, Ian; Brandt, Andrew

    2010-02-01

    In 10 trillionths of a second light travels 3mm. Our group at UTA is currently developing the most precise time of flight (TOF) detector ever deployed in a collider experiment, with a resolution on this 10 picosecond scale. In conjunction with several other universities we have proposed to install a fast timing system as part of a proton detector upgrade to the main ATLAS detector at the Large Hadron Collider (LHC) . Precise measurement of the timing of proton tracks will allow rejection of background to the physics processes of interest, which include the elusive Higgs Boson. Laser based tests at UTA allow us to measure the response of our detectors downstream electronics including constant fraction discriminators, amplifiers and most importantly the microchannel plate photomultiplier tubes, which are at the heart of this fast-timing system. By isolating the individual components of the detector in this fashion, we can fully characterize each device's response. My research is part of the ongoing data analysis using the CERN analysis package ROOT. By closely examining the pulse height, time difference distributions, and transit time spread (TTS) we are be able to understand the performance of the detectors and electronics in laser and beam tests to better prepare ourselves for future test beams and eventually full scale installation and operation. I will present the latest performance test results from data I have analyzed. )

  19. Barrel time-of-flight detector for the PANDA experiment at FAIR

    NASA Astrophysics Data System (ADS)

    Gruber, L.; Brunner, S. E.; Marton, J.; Orth, H.; Suzuki, K.

    2016-07-01

    The barrel time-of-flight detector for the PANDA experiment at FAIR is foreseen as a Scintillator Tile (SciTil) Hodoscope based on several thousand small plastic scintillator tiles read-out with directly attached Silicon Photomultipliers (SiPMs). The main tasks of the system are an accurate determination of the time origin of particle tracks to avoid event mixing at high collision rates, relative time-of-flight measurements as well as particle identification in the low momentum regime. The main requirements are the use of a minimum material amount and a time resolution of σ < 100 ps. We have performed extensive optimization studies and prototype tests to prove the feasibility of the SciTil design and finalize the R&D phase. In a 2.7 GeV/c proton beam at Forschungszentrum Jülich a time resolution of about 80 ps has been achieved using SiPMs from KETEK and Hamamatsu with an active area of 3 × 3mm2. Employing the Digital Photon Counter from Philips a time resolution of about 30 ps has been reached.

  20. Development of scalable electronics for the TORCH time-of-flight detector

    NASA Astrophysics Data System (ADS)

    Gao, R.; Brook, N.; Castillo García, L.; Cowie, E. N.; Cussans, D.; Forty, R.; Frei, C.; Gys, T.; Harnew, N.; Piedigrossi, D.; Van Dijk, M.

    2015-02-01

    The TORCH detector is proposed for the low-momentum particle identification upgrade of the LHCb experiment. It combines Time-Of-Flight and Cherenkov techniques to achieve charged particle separation up to 10 GeV/c. This requires a time resolution of 70 ps for single photons. Existing electronics has already demonstrated a 26 ps intrinsic time resolution; however the channel count and density need improvements for future micro-channel plate devices. This paper will report on a scalable design using custom ASICs (NINO-32 and HPTDC). The system provides up to 8 × 64 channels for a single micro-channel plate device. It is also designed to read out micro-channel plate tubes with charge-sharing technique.

  1. First isochronous mass measurements with two time-of-flight detectors at CSRe

    NASA Astrophysics Data System (ADS)

    Xing, Y. M.; Wang, M.; Zhang, Y. H.; Shuai, P.; Xu, X.; Chen, R. J.; Yan, X. L.; Tu, X. L.; Zhang, W.; Fu, C. Y.; Xu, H. S.; Litvinov, Yu A.; Blaum, K.; Chen, X. C.; Ge, Z.; Gao, B. S.; Huang, W. J.; Litvinov, S. A.; Liu, D. W.; Ma, X. W.; Mao, R. S.; Xiao, G. Q.; Yang, J. C.; Yuan, Y. J.; Zeng, Q.; Zhou, X. H.

    2015-11-01

    Isochronous mass spectrometry (IMS) established in heavy-ion storage rings has proven to be a powerful tool for mass measurements of short-lived nuclides. In IMS, the revolution times of stored ions should be independent of their velocity spread. However, this isochronous condition is fulfilled only in the first order and in a small range of revolution times. To correct for non-isochronicity, an additional measure of the velocity or magnetic rigidity of each stored ion is required. For this purpose two new time-of-flight (TOF) detectors were installed in one of the straight sections of the experimental cooler storage ring in Lanzhou. It is expected that the resolving power of the IMS will significantly be improved with such a double-TOF arrangement. The double-TOF system was tested in a recent experiment with the 78Kr fragments. Some of the experimental results are presented in this contribution.

  2. Time-of-flight measurement of fast neutrons with Timepix detectors

    NASA Astrophysics Data System (ADS)

    Bergmann, B.; Nelson, R. O.; O'Donnell, J. M.; Pospisil, S.; Solc, J.; Takai, H.; Vykydal, Z.

    2014-05-01

    Timepix pixel detectors have been used to study the response of silicon hybrid pixel detectors to fast neutrons from a pulsed neutron beam at WNR FP30R, a 14 m long flight path, in the Los Alamos Neutron Science Center. Neutrons with kinetic energies up to 600 MeV were available. In order to enhance the conversion of neutrons to energetic charged particles, several converter foils and filters were attached to the 300 μm thick silicon sensor, i.e. polyethylene, polyethylene with aluminum, 6LiF, 6LiF with aluminum, aluminum. The Time-of-Arrival mode of the Timepix detectors has permitted the application of the Time-of-Flight (TOF) technique for the assignment of the detected interactions in the form of clusters (groups of adjacent pixels) in the pixel matrix, to the kinetic energies of the incident neutrons. It was found that, for lower neutron energies ( ~ MeV range) the cluster rates below the polyethylene and the polyethylene and aluminum region, produced by recoil protons, are a good measure for the mean kinetic energies of neutrons. For energies above 50 MeV nuclear reactions in the silicon dominate the detector response. In this energy range the shape of the clusters indicates the neutron kinetic energy.

  3. A time-of-flight detector for thermal neutrons from radiotherapy Linacs

    NASA Astrophysics Data System (ADS)

    Conti, V.; Bartesaghi, G.; Bolognini, D.; Mascagna, V.; Perboni, C.; Prest, M.; Scazzi, S.; Mozzanica, A.; Cappelletti, P.; Frigerio, M.; Gelosa, S.; Monti, A.; Ostinelli, A.; Giannini, G.; Vallazza, E.

    2007-10-01

    Boron Neutron Capture Therapy (BNCT) is a therapeutic technique exploiting the release of dose inside the tumour cell after a fission of a 10B nucleus following the capture of a thermal neutron. BNCT could be the treatment for extended tumors (liver, stomach, lung), radio-resistant ones (melanoma) or tumours surrounded by vital organs (brain). The application of BNCT requires a high thermal neutron flux (>5×108 n cm-2 s-1) with the correct energy spectrum (neutron energy <10 keV), two requirements that for the moment are fulfilled only by nuclear reactors. The INFN PhoNeS (Photo Neutron Source) project is trying to produce such a neutron beam with standard radiotherapy Linacs, maximizing with a dedicated photo-neutron converter the neutrons produced by Giant Dipole Resonance by a high energy ( >8 MeV) photon beam. In this framework, we have developed a real-time detector to measure the thermal neutron time-of -flight to compute the flux and the energy spectrum. Given the pulsed nature of Linac beams, the detector is a single neutron counting system made of a scintillator detecting the photon emitted after the neutron capture by the hydrogen nuclei. The scintillator signal is sampled by a dedicated FPGA clock thus obtaining the exact arrival time of the neutron itself. The paper will present the detector and its electronics, the feasibility measurements with a Varian Clinac 1800/2100CD and comparison with a Monte Carlo simulation.

  4. CVD Diamond Detectors for Current Mode Neutron Time-of-Flight Spectroscopy at OMEGA/NIF

    SciTech Connect

    Schmid, G J; Friensehner, A F; Glebov, V Y; Hargrove, D R; Hatchett, S P; Izumi, N; Lerche, R A; Phillips, T W; Sangster, T C; Sibernagel, C; Stoeckl, C

    2001-06-19

    As part of a laser fusion diagnostic development program, we have performed pulsed neutron and pulsed laser tests of a CVD diamond detector manufactured from DIAFILM, a commercial grade of CVD diamond. The laser tests were performed at the short pulse UV laser at Bechtel Nevada in Livermore, CA. The pulsed neutrons were provided by DT capsule implosions at the OMEGA laser fusion facility in Rochester, NY. From these tests, we have determined the impulse response to be 250 ps fwhm for an applied E-field of 500 V/mm. Additionally, we have determined the sensitivity to be 2.8 mA/W at 500 V/mm and 4.5 mA/W at 1000 V/mm (2 to 6x times higher than reported values for natural Type IIa diamond). These detector characteristics allow us to conceive of a neutron time-of-flight current mode spectrometer based on CVD diamond. Such an instrument would sit inside the laser fusion target chamber close to TCC, and would record neutron spectra fast enough such that backscattered neutrons and y rays from the target chamber wall would not be a concern. However, the data we have taken show that the Electromagnetic Pulse (EMP) noise could be a limiting factor in performance. Determining the degree to which this noise can be shielded will be an important subject of future tests.

  5. A laser diode based system for calibration of fast time-of-flight detectors

    NASA Astrophysics Data System (ADS)

    Bertoni, R.; Bonesini, M.; de Bari, A.; Rossella, M.

    2016-05-01

    A system based on commercially available items, such as a laser diode, emitting in the visible range ~ 400 nm, and multimode fiber patches, fused fiber splitters and optical switches may be assembled, for time calibration of multi-channels time-of-flight (TOF) detectors with photomultipliers' (PMTs') readout. As available laser diode sources have unfortunately limited peak power, the main experimental problem is the tight light power budget of such a system. In addition, while the technology for fused fiber splitters is common in the Telecom wavelength range (λ ~ 850, 1300–1500 nm), it is not easily available in the visible one. Therefore, extensive laboratory tests had to be done on purpose, to qualify the used optical components, and a full scale timing calibration prototype was built. Obtained results show that with such a system, a calibration resolution (σ) in the range 20–30 ps may be within reach. Therefore, fast multi-channels TOF detectors, with timing resolutions in the range 50–100 ps, may be easily calibrated in time. Results on tested optical components may be of interest also for time calibration of different light detection systems based on PMTs, as the ones used for detection of the vacuum ultraviolet scintillation light emitted by ionizing particles in large LAr TPCs.

  6. Characterization studies of silicon photomultipliers and crystals matrices for a novel time of flight PET detector

    NASA Astrophysics Data System (ADS)

    Auffray, E.; Ben Mimoun Bel Hadj, F.; Cortinovis, D.; Doroud, K.; Garutti, E.; Lecoq, P.; Liu, Z.; Martinez, R.; Paganoni, M.; Pizzichemi, M.; Silenzi, A.; Xu, C.; Zvolský, M.

    2015-06-01

    This paper describes the characterization of crystal matrices and silicon photomultiplier arrays for a novel Positron Emission Tomography (PET) detector, namely the external plate of the EndoTOFPET-US system. The EndoTOFPET-US collaboration aims to integrate Time-Of-Flight PET with ultrasound endoscopy in a novel multimodal device, capable to support the development of new biomarkers for prostate and pancreatic tumors. The detector consists in two parts: a PET head mounted on an ultrasound probe and an external PET plate. The challenging goal of 1 mm spatial resolution for the PET image requires a detector with small crystal size, and therefore high channel density: 4096 LYSO crystals individually readout by Silicon Photomultipliers (SiPM) make up the external plate. The quality and properties of these components must be assessed before the assembly. The dark count rate, gain, breakdown voltage and correlated noise of the SiPMs are measured, while the LYSO crystals are evaluated in terms of light yield and energy resolution. In order to effectively reduce the noise in the PET image, high time resolution for the gamma detection is mandatory. The Coincidence Time Resolution (CTR) of all the SiPMs assembled with crystals is measured, and results show a value close to the demanding goal of 200 ps FWHM. The light output is evaluated for every channel for a preliminary detector calibration, showing an average of about 1800 pixels fired on the SiPM for a 511 keV interaction. Finally, the average energy resolution at 511 keV is about 13 %, enough for effective Compton rejection.

  7. CVD Diamond Detectors for Current Mode Neutron Time-of-Flight Spectroscopy at OMEGA/NIF

    SciTech Connect

    G. J. Schmid; V. Yu. Glebov; A. V. Friensehner; D. R. Hargrove; S. P. Hatchett; N. Izumi; R. A. Lerche; T. W. Phillips; T. C. Sangster; C. Silbernagel; C. Stoecki

    2001-07-01

    We have performed pulsed neutron and pulsed laser tests of a CVD diamond detector manufactured from DIAFILM, a commercial grade of CVD diamond. The laser tests were performed at the short pulse UV laser at Bechtel Nevada in Livermore, CA. The pulsed neutrons were provided by DT capsule implosions at the OMEGA laser fusion facility in Rochester, NY. From these tests, we have determined the impulse response to be 250 ps fwhm for an applied E-field of 500 V/mm. Additionally, we have determined the sensitivity to be 2.4 mA/W at 500 V/mm and 4.0 mA/W at 1000 V/mm. These values are approximately 2 to 5x times higher than those reported for natural Type IIa diamond at similar E-field and thickness (1mm). These characteristics allow us to conceive of a neutron time-of-flight current mode spectrometer based on CVD diamond. Such an instrument would sit inside the laser fusion target chamber close to target chamber center (TCC), and would record neutron spectra fast enough such that backscattered neutrons and x-rays from the target chamber wall would not be a concern. The acquired neutron spectra could then be used to extract DD fuel areal density from the downscattered secondary to secondary ratio.

  8. A fast preamplifier concept for SiPM-based time-of-flight PET detectors

    NASA Astrophysics Data System (ADS)

    Huizenga, J.; Seifert, S.; Schreuder, F.; van Dam, H. T.; Dendooven, P.; Löhner, H.; Vinke, R.; Schaart, D. R.

    2012-12-01

    Silicon photomultipliers (SiPMs) offer high gain and fast response to light, making them interesting for fast timing applications such as time-of-flight (TOF) PET. To fully exploit the potential of these photosensors, dedicated preamplifiers that do not deteriorate the rise time and signal-to-noise ratio are crucial. Challenges include the high sensor capacitance, typically >300 pF for a 3 mm×3 mm SiPM sensor, as well as oscillation issues. Here we present a preamplifier concept based on low noise, high speed transistors, designed for optimum timing performance. The input stage consists of a transimpedance common-base amplifier with a very low input impedance even at high frequencies, which assures a good linearity and avoids that the high detector capacitance affects the amplifier bandwidth. The amplifier has a fast timing output as well as a 'slow' energy output optimized for determining the total charge content of the pulse. The rise time of the amplifier is about 300 ps. The measured coincidence resolving time (CRT) for 511 keV photon pairs using the amplifiers in combination with 3 mm×3 mm SiPMs (Hamamatsu MPPC-S10362-33-050C) coupled to 3 mm×3 mm×5 mm LaBr3:Ce and LYSO:Ce crystals equals 95 ps FWHM and 138 ps FWHM, respectively.

  9. A gas ionisation detector in the axial (Bragg) geometry used for the time-of-flight elastic recoil detection analysis

    SciTech Connect

    Siketić, Zdravko; Skukan, Natko; Bogdanović Radović, Iva

    2015-08-15

    In this paper, time-of-flight elastic recoil detection analysis spectrometer with a newly constructed gas ionization detector for energy detection is presented. The detector is designed in the axial (Bragg) geometry with a 3 × 3 array of 50 nm thick Si{sub 3}N{sub 4} membranes as an entrance window. 40 mbar isobutane gas was sufficient to stop a 30 MeV primary iodine beam as well as all recoils in the detector volume. Spectrometer and detector performances were determined showing significant improvement in the mass and energy resolution, respectively, comparing to the spectrometer with a standard silicon particle detector for an energy measurement.

  10. Signal encoding method for a time-of-flight PET detector using a silicon photomultiplier array

    NASA Astrophysics Data System (ADS)

    Kwon, Sun Il; Lee, Jae Sung

    2014-10-01

    The silicon photomultiplier (SiPM) is a promising photosensor for magnetic resonance (MR) compatible time-of-flight (TOF) positron emission tomography (PET) scanners. The compact size of the SiPM allows direct one-to-one coupling between the scintillation crystal and the photosensor, yielding better timing and energy resolutions than the light sharing methods that have to be used in photomultiplier tube (PMT) PET systems. However, the one-to-one coupling scheme requires a huge volume of readout and processing electronics if no electric signal multiplexing or encoding scheme is properly applied. In this paper, we develop an electric signal encoding scheme for SiPM array based TOF PET detector blocks with the aim of reducing the complexity and volume of the signal readout and processing electronics. In an M×N SiPM array, the output signal of each channel in the SiPM array is divided into two signal lines. These output lines are then tied together in row and column lines. The row and column signals are used to measure the energy and timing information (or vice versa) of each incident gamma-ray event, respectively. Each SiPM channel was directly coupled to a 3×3×20 mm3 LGSO crystal. The reference detector, which was used to measure timing, consisted of an R9800 PMT and a 4×4×10 mm3 LYSO crystal and had a single time resolution of ~200 ps (FWHM). Leading edge discriminators were used to determine coincident events. Dedicated front-end electronics were developed, and the timing and energy resolutions of SiPM arrays with different array sizes (4×4, 8×8, and 12×12) were compared. Breakdown voltage of each SiPM channel was measured using energy spectra within various bias voltages. Coincidence events were measured using a 22Na point source. The average coincidence time resolution of 4×4, 8×8, and 12×12 SiPM arrays were 316 ps, 320 ps, and 335 ps (FWHM), respectively. The energy resolution of 4×4, 8×8, and 12×12 SiPM arrays were 11.8%, 12.5%, and 12.8% (FWHM

  11. The Silicon Pixel Detector for ALICE Experiment

    SciTech Connect

    Fabris, D.; Bombonati, C.; Dima, R.; Lunardon, M.; Moretto, S.; Pepato, A.; Bohus, L. Sajo; Scarlassara, F.; Segato, G.; Shen, D.; Turrisi, R.; Viesti, G.; Anelli, G.; Boccardi, A.; Burns, M.; Campbell, M.; Ceresa, S.; Conrad, J.; Kluge, A.; Kral, M.

    2007-10-26

    The Inner Tracking System (ITS) of the ALICE experiment is made of position sensitive detectors which have to operate in a region where the track density may be as high as 50 tracks/cm{sup 2}. To handle such densities detectors with high precision and granularity are mandatory. The Silicon Pixel Detector (SPD), the innermost part of the ITS, has been designed to provide tracking information close to primary interaction point. The assembly of the entire SPD has been completed.

  12. A new Time-of-Flight mass measurement project for exotic nuclei and ultra-high precision detector development

    NASA Astrophysics Data System (ADS)

    Sun, Bao-Hua; Zhao, Jian-Wei; Yan, Wen-Qi; Le, X. Y.; Lin, Wen-Jian; Song, C. Y.; Tanihata, Isao; Terashima, S.; Wang, T. F.; Zhang, S. S.; Zhu, L. H.

    2016-02-01

    The time-of-flight (TOF) mass spectrometry (MS), a high-resolution magnetic spectrometer equipped with a fast particle tracking system, is well recognized by its ability in weighing the most exotic nuclei. Currently such TOF-MS can achieve a mass resolution power of about 2×10-4. We show that the mass resolution can be further improved by one order of magnitude with augmented timing and position detectors. We report the progress in developing ultra-fast detectors to be used in TOF-MS.

  13. Investigating ion-surface collisions with a niobium superconducting tunnel junction detector in a time-of-flight mass spectrometer

    PubMed

    Westmacott; Zhong; Frank; Friedrich; Labov; Benner

    2000-01-01

    The performance of an energy sensitive, niobium superconducting tunnel junction (STJ) detector is investigated by measuring the pulse height produced by impacting molecular and atomic ions at different kinetic energies. Ions are produced by laser desorption and matrix-assisted laser desorption in a time-of-flight mass spectrometer. Our results show that the STJ detector pulse height decreases for increasing molecular ion mass, passes through a minimum at around 2000 Da, and then increases with increasing mass of molecular ions above 2000 Da. The detector does not show a decline in sensitivity for high mass ions as is observed with microchannel plate ion detectors. These detector plus height measurements are discussed in terms of several physical mechanisms involved in an ion-surface collision. PMID:10775095

  14. Investigating ion-surface collisions with a niobium superconducting tunnel junction detector in a time-of-flight mass spectrometer

    SciTech Connect

    Westmacott, G.; Zhong, F.; Frank, M.; Friedrich, S.; Labov, S.; Benner, W.H.

    1999-12-01

    The performance of an energy sensitive, niobium superconducting tunnel junction detector is investigated by measuring the pulse height produced by impacting molecular and atomic ions at different kinetic energies. Ions are produced by laser resorption and matrix-assisted laser desorption in a time-of-flight mass spectrometer. Results show that the STJ detector pulse height decreases for increasing molecular ion mass, passes through a minimum at around 2000 Da, and the increases with increasing mass of molecular ions above 2000Da. The detector does not show a decline in sensitivity for high mass ions as is observed with microchannel plate ion detectors. These detector plus height measurements are discussed in terms of several physical mechanisms involved in an ion-surface collision.

  15. Use of a large time-compensated scintillation detector in neutron time-of-flight measurements

    DOEpatents

    Goodman, Charles D.

    1979-01-01

    A scintillator for neutron time-of-flight measurements is positioned at a desired angle with respect to the neutron beam, and as a function of the energy thereof, such that the sum of the transit times of the neutrons and photons in the scintillator are substantially independent of the points of scintillations within the scintillator. Extrapolated zero timing is employed rather than the usual constant fraction timing. As a result, a substantially larger scintillator can be employed that substantially increases the data rate and shortens the experiment time.

  16. Parallel Configuration For Fast Superconducting Strip Line Detectors With Very Large Area In Time Of Flight Mass Spectrometry

    SciTech Connect

    Casaburi, A.; Zen, N.; Suzuki, K.; Ohkubo, M.; Ejrnaes, M.; Cristiano, R.; Pagano, S.

    2009-12-16

    We realized a very fast and large Superconducting Strip Line Detector based on a parallel configuration of nanowires. The detector with size 200x200 {mu}m{sup 2} recorded a sub-nanosecond pulse width of 700 ps in FWHM (400 ps rise time and 530 ps relaxation time) for lysozyme monomers/multimers molecules accelerated at 175 keV in a Time of Flight Mass Spectrometer. This record is the best in the class of superconducting detectors and comparable with the fastest NbN superconducting single photon detector of 10x10 {mu}m{sup 2}. We succeeded in acquiring mass spectra as the first step for a scale-up to {approx}mm pixel size for high throughput MS analysis, while keeping a fast response.

  17. Design of Cherenkov bars for the optical part of the time-of-flight detector in Geant4.

    PubMed

    Nozka, L; Brandt, A; Rijssenbeek, M; Sykora, T; Hoffman, T; Griffiths, J; Steffens, J; Hamal, P; Chytka, L; Hrabovsky, M

    2014-11-17

    We present the results of studies devoted to the development and optimization of the optical part of a high precision time-of-flight (TOF) detector for the Large Hadron Collider (LHC). This work was motivated by a proposal to use such a detector in conjunction with a silicon detector to tag and measure protons from interactions of the type p + p → p + X + p, where the two outgoing protons are scattered in the very forward directions. The fast timing detector uses fused silica (quartz) bars that emit Cherenkov radiation as a relativistic particle passes through and the emitted Cherenkov photons are detected by, for instance, a micro-channel plate multi-anode Photomultiplier Tube (MCP-PMT). Several possible designs are implemented in Geant4 and studied for timing optimization as a function of the arrival time, and the number of Cherenkov photons reaching the photo-sensor. PMID:25402137

  18. Fusion neutron detector for time-of-flight measurements in z-pinch and plasma focus experiments.

    PubMed

    Klir, D; Kravarik, J; Kubes, P; Rezac, K; Litseva, E; Tomaszewski, K; Karpinski, L; Paduch, M; Scholz, M

    2011-03-01

    We have developed and tested sensitive neutron detectors for neutron time-of-flight measurements in z-pinch and plasma focus experiments with neutron emission times in tens of nanoseconds and with neutron yields between 10(6) and 10(12) per one shot. The neutron detectors are composed of a BC-408 fast plastic scintillator and Hamamatsu H1949-51 photomultiplier tube (PMT). During the calibration procedure, a PMT delay was determined for various operating voltages. The temporal resolution of the neutron detector was measured for the most commonly used PMT voltage of 1.4 kV. At the PF-1000 plasma focus, a novel method of the acquisition of a pulse height distribution has been used. This pulse height analysis enabled to determine the single neutron sensitivity for various neutron energies and to calibrate the neutron detector for absolute neutron yields at about 2.45 MeV. PMID:21456735

  19. Deuterium-tritium neutron yield measurements with the 4.5 m neutron-time-of-flight detectors at NIF

    SciTech Connect

    Moran, M. J.; Bond, E. J.; Clancy, T. J.; Eckart, M. J.; Khater, H. Y.; Glebov, V. Yu.

    2012-10-15

    The first several campaigns of laser fusion experiments at the National Ignition Facility (NIF) included a family of high-sensitivity scintillator/photodetector neutron-time-of-flight (nTOF) detectors for measuring deuterium-deuterium (DD) and DT neutron yields. The detectors provided consistent neutron yield (Y{sub n}) measurements from below 10{sup 9} (DD) to nearly 10{sup 15} (DT). The detectors initially demonstrated detector-to-detector Y{sub n} precisions better than 5%, but lacked in situ absolute calibrations. Recent experiments at NIF now have provided in situ DT yield calibration data that establish the absolute sensitivity of the 4.5 m differential tissue harmonic imaging (DTHI) detector with an accuracy of {+-}10% and precision of {+-}1%. The 4.5 m nTOF calibration measurements also have helped to establish improved detector impulse response functions and data analysis methods, which have contributed to improving the accuracy of the Y{sub n} measurements. These advances have also helped to extend the usefulness of nTOF measurements of ion temperature and downscattered neutron ratio (neutron yield 10-12 MeV divided by yield 13-15 MeV) with other nTOF detectors.

  20. Time-of-flight ERD with a 200 mm2 Si3N4 window gas ionization chamber energy detector

    NASA Astrophysics Data System (ADS)

    Julin, Jaakko; Laitinen, Mikko; Sajavaara, Timo

    2014-08-01

    Low energy heavy ion elastic recoil detection work has been carried out in Jyväskylä since 2009 using home made timing detectors, a silicon energy detector and a timestamping data acquisition setup forming a time-of-flight-energy telescope. In order to improve the mass resolution of the setup a new energy detector was designed to replace the silicon solid state detector, which suffered from radiation damage and had poor resolution for heavy recoils. In this paper the construction and operation of an isobutane filled gas ionization chamber with a 14 × 14 mm2 100 nm thick silicon nitride window are described. In addition to greatly improved energy resolution for heavy ions, the detector is also able to detect hydrogen recoils simultaneously in the energy range of 100-1000 keV. Additionally the detector has position sensitivity by means of timing measurement, which can be performed without compromising the performance of the detector in any other way. The achieved position sensitivity improves the depth resolution near the surface.

  1. V0L detector at ALICE

    NASA Astrophysics Data System (ADS)

    Alfaro, Ruben; Becerril, Ana; Belmont-Moreno, Ernesto; Martinez-Davalos, Arnulfo; Menchaca-Rocha, Arturo

    2003-04-01

    The V0 system is part of the FMD in the ALICE experiment. This system consist of two sub-detectors: V0L and V0R located on both sides of the collision vertex. The system must provide information about: minimum bias trigger and multiplicity. It also plays an important role at level 0 trigger. Therefore, besides the mechanical constrains, timing and good light collection are important issues in the design and construction of both sub-detectors. Mechanical construction and results of the beam test performed to V0L prototype, being built at the UNAM, are presented. Improvements and alternative designs will be discussed.

  2. A technique for verifying the input response function of neutron time-of-flight scintillation detectors using cosmic rays.

    PubMed

    Bonura, M A; Ruiz, C L; Fehl, D L; Cooper, G W; Chandler, G; Hahn, K D; Nelson, A J; Styron, J D; Torres, J A

    2014-11-01

    An accurate interpretation of DD or DT fusion neutron time-of-flight (nTOF) signals from current mode detectors employed at the Z-facility at Sandia National Laboratories requires that the instrument response functions (IRF's) be deconvolved from the measured nTOF signals. A calibration facility that produces detectable sub-ns radiation pulses is typically used to measure the IRF of such detectors. This work, however, reports on a simple method that utilizes cosmic radiation to measure the IRF of nTOF detectors, operated in pulse-counting mode. The characterizing metrics reported here are the throughput delay and full-width-at-half-maximum. This simple approach yields consistent IRF results with the same detectors calibrated in 2007 at a LINAC bremsstrahlung accelerator (Idaho State University). In particular, the IRF metrics from these two approaches and their dependence on the photomultipliers bias agree to within a few per cent. This information may thus be used to verify if the IRF for a given nTOF detector employed at Z has changed since its original current-mode calibration and warrants re-measurement. PMID:25430209

  3. A technique for verifying the input response function of neutron time-of-flight scintillation detectors using cosmic rays

    SciTech Connect

    Bonura, M. A.; Cooper, G. W.; Nelson, A. J.; Styron, J. D.; Ruiz, C. L. Fehl, D. L.; Chandler, G.; Hahn, K. D.; Torres, J. A.

    2014-11-15

    An accurate interpretation of DD or DT fusion neutron time-of-flight (nTOF) signals from current mode detectors employed at the Z-facility at Sandia National Laboratories requires that the instrument response functions (IRF’s) be deconvolved from the measured nTOF signals. A calibration facility that produces detectable sub-ns radiation pulses is typically used to measure the IRF of such detectors. This work, however, reports on a simple method that utilizes cosmic radiation to measure the IRF of nTOF detectors, operated in pulse-counting mode. The characterizing metrics reported here are the throughput delay and full-width-at-half-maximum. This simple approach yields consistent IRF results with the same detectors calibrated in 2007 at a LINAC bremsstrahlung accelerator (Idaho State University). In particular, the IRF metrics from these two approaches and their dependence on the photomultipliers bias agree to within a few per cent. This information may thus be used to verify if the IRF for a given nTOF detector employed at Z has changed since its original current-mode calibration and warrants re-measurement.

  4. A New Neutron Time-of-Flight Detector for DT Yield and Ion-Temperature Measurements on OMEGA

    NASA Astrophysics Data System (ADS)

    Glebov, V. Yu.; Forrest, C. J.; Knauer, J. P.; Regan, S. P.; Sangster, T. C.; Stoeckl, C.

    2015-11-01

    A new neutron time-of-flight (nTOF) detector for DT yield and ion-temperature measurements in DT implosions on the OMEGA Laser System was designed, fabricated, tested, and calibrated. The goal of this detector is to provide a second line of sight for DT yield and ion-temperature measurements in the 1 ×1012 to 1014 yield range. The nTOF detector consists of a 40-mm-diam, 20-mm-thick BC-422Q(1%) scintillator coupled with a one-stage Photek PMT-140 photomultiplier tube. To avoid PMT saturation at high yields a neutral density filter ND1 is inserted between the scintillator and PMT. Both the scintillator and PMT are shielded from hard x rays by 5 mm of lead on all sides and 10 mm in the direction of the target. The nTOF detector is located at 15.8 m from target chamber center in the OMEGA Target Bay. The design details and calibration results of this nTOF detector in DT implosions on OMEGA will be presented. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  5. A technique for verifying the input response function of neutron time-of-flight scintillation detectors using cosmic raysa)

    NASA Astrophysics Data System (ADS)

    Bonura, M. A.; Ruiz, C. L.; Fehl, D. L.; Cooper, G. W.; Chandler, G.; Hahn, K. D.; Nelson, A. J.; Styron, J. D.; Torres, J. A.

    2014-11-01

    An accurate interpretation of DD or DT fusion neutron time-of-flight (nTOF) signals from current mode detectors employed at the Z-facility at Sandia National Laboratories requires that the instrument response functions (IRF's) be deconvolved from the measured nTOF signals. A calibration facility that produces detectable sub-ns radiation pulses is typically used to measure the IRF of such detectors. This work, however, reports on a simple method that utilizes cosmic radiation to measure the IRF of nTOF detectors, operated in pulse-counting mode. The characterizing metrics reported here are the throughput delay and full-width-at-half-maximum. This simple approach yields consistent IRF results with the same detectors calibrated in 2007 at a LINAC bremsstrahlung accelerator (Idaho State University). In particular, the IRF metrics from these two approaches and their dependence on the photomultipliers bias agree to within a few per cent. This information may thus be used to verify if the IRF for a given nTOF detector employed at Z has changed since its original current-mode calibration and warrants re-measurement.

  6. A highly efficient neutron time-of-flight detector for inertial confinement fusion experiments

    NASA Astrophysics Data System (ADS)

    Izumi, N.; Yamaguchi, K.; Yamagajo, T.; Nakano, T.; Kasai, T.; Urano, T.; Azechi, H.; Nakai, S.; Iida, T.

    1999-01-01

    We have developed the highly efficient neutron detector system MANDALA for the inertial-confinement-fusion experiment. The MANDALA system consists of 842 elements plastic scintillation detectors and data acquisition electronics. The detection level is the yield of 1.2×105 for 2.5 MeV and 1×105 for 14.1 MeV neutrons (with 100 detected hits). We have calibrated the intrinsic detection efficiencies of the detector elements using a neutron generator facility. Timing calibration and integrity test of the system were also carried out with a 60Co γ ray source. MANDALA system was applied to the implosion experiments at the GEKKO XII laser facility. The integrity test was carried out by implosion experiments.

  7. Mechanical Modulation of Phonon-Assisted Field Emission in a Silicon Nanomembrane Detector for Time-of-Flight Mass Spectrometry

    PubMed Central

    Park, Jonghoo; Blick, Robert H.

    2016-01-01

    We demonstrate mechanical modulation of phonon-assisted field emission in a free-standing silicon nanomembrane detector for time-of-flight mass spectrometry of proteins. The impacts of ion bombardment on the silicon nanomembrane have been explored in both mechanical and electrical points of view. Locally elevated lattice temperature in the silicon nanomembrane, resulting from the transduction of ion kinetic energy into thermal energy through the ion bombardment, induces not only phonon-assisted field emission but also a mechanical vibration in the silicon nanomembrane. The coupling of these mechanical and electrical phenomenon leads to mechanical modulation of phonon-assisted field emission. The thermal energy relaxation through mechanical vibration in addition to the lateral heat conduction and field emission in the silicon nanomembrane offers effective cooling of the nanomembrane, thereby allowing high resolution mass analysis. PMID:26861329

  8. Characterization of a scintillating mini-detector for time-of-flight positron emission tomography with depth-of-interaction

    NASA Astrophysics Data System (ADS)

    Cosentino, Luigi; Finocchiaro, Paolo; Pappalardo, Alfio; Garibaldi, Franco

    2012-08-01

    By exploiting a suitable treatment of the scintillator surfaces, along with silicon photomultiplier photodetectors and specific algorithms for raw data analysis, we achieved a remarkable tradeoff between energy, time, and depth-of-interaction (DOI) resolution, thus supporting the feasibility of a prostate time-of-flight positron emission tomography probe, magnetic resonance imaging compatible, with the required features and performance. In numbers this means a detector element of 1.5 mm × 1.5 mm × 10 mm, promising to achieve at the same time energy resolution around 11.5%, coincidence resolving time around 300 ps corresponding to a space resolution <5 cm along the line of response, and DOI resolution even below 1 mm. We stress that such a time resolution allows to increase significantly the noise equivalent counting rate, and consequently improve the image quality and the lesion detection capability.

  9. Mechanical Modulation of Phonon-Assisted Field Emission in a Silicon Nanomembrane Detector for Time-of-Flight Mass Spectrometry.

    PubMed

    Park, Jonghoo; Blick, Robert H

    2016-01-01

    We demonstrate mechanical modulation of phonon-assisted field emission in a free-standing silicon nanomembrane detector for time-of-flight mass spectrometry of proteins. The impacts of ion bombardment on the silicon nanomembrane have been explored in both mechanical and electrical points of view. Locally elevated lattice temperature in the silicon nanomembrane, resulting from the transduction of ion kinetic energy into thermal energy through the ion bombardment, induces not only phonon-assisted field emission but also a mechanical vibration in the silicon nanomembrane. The coupling of these mechanical and electrical phenomenon leads to mechanical modulation of phonon-assisted field emission. The thermal energy relaxation through mechanical vibration in addition to the lateral heat conduction and field emission in the silicon nanomembrane offers effective cooling of the nanomembrane, thereby allowing high resolution mass analysis. PMID:26861329

  10. Assessment of a high-resolution candidate detector for prostate time-of-flight positron emission tomography

    NASA Astrophysics Data System (ADS)

    Cosentino, Luigi; Finocchiaro, Paolo; Pappalardo, Alfio; Garibaldi, Franco

    2012-11-01

    We report on the measurements performed using a 22Na source on a detector element for a magnetic resonance imaging-compatible time-of-flight-positron emission tomography endorectal prostate probe, with depth-of-interaction sensitivity. It is made from a LYSO scintillator crystal, wrapped with Lumirror, readout at both ends by means of silicon photomultipliers. With a detailed description of the data analysis procedure, we show that our results point to a 400 ps coincidence resolving time and, at the same time, to a depth-of-interaction resolution of 1 mm. These appealing features, along with the tiny 1.5 mm × 1.5 mm × 10 mm crystal size, are quite promising in view of the realization of a prototype probe.

  11. Characterization of a scintillating mini-detector for time-of-flight positron emission tomography with depth-of-interaction.

    PubMed

    Cosentino, Luigi; Finocchiaro, Paolo; Pappalardo, Alfio; Garibaldi, Franco

    2012-08-01

    By exploiting a suitable treatment of the scintillator surfaces, along with silicon photomultiplier photodetectors and specific algorithms for raw data analysis, we achieved a remarkable tradeoff between energy, time, and depth-of-interaction (DOI) resolution, thus supporting the feasibility of a prostate time-of-flight positron emission tomography probe, magnetic resonance imaging compatible, with the required features and performance. In numbers this means a detector element of 1.5 mm × 1.5 mm × 10 mm, promising to achieve at the same time energy resolution around 11.5%, coincidence resolving time around 300 ps corresponding to a space resolution <5 cm along the line of response, and DOI resolution even below 1 mm. We stress that such a time resolution allows to increase significantly the noise equivalent counting rate, and consequently improve the image quality and the lesion detection capability. PMID:22938315

  12. A novel grid geometry of long detector modules for a time-of-flight system

    NASA Astrophysics Data System (ADS)

    Daskalakis, G.; Panagiotou, A. D.; Ioannidis, G. S.

    1993-05-01

    We present a novel geometry for a large area TOF system, consisting of long detector modules arranged in X- Y directions in two planes. Such a GRID geometry has many advantages, including better particle identification and fewer modules (channels) for the same number of identified particles, compared to a single plane geometry, i.e. a TILE arrangement. We also present the mathematical algorithm for the general case of an n-plane GRID geometry and discuss its applicability.

  13. Determining time resolution of microchannel plate detectors for electron time-of-flight spectrometers.

    PubMed

    Zhang, Qi; Zhao, Kun; Chang, Zenghu

    2010-07-01

    The temporal resolution of a 40 mm diameter chevron microchannel plate (MCP) detector followed by a constant fraction discriminator and a time-to-digital converter was determined by using the third order harmonic of 25 fs Ti:sapphire laser pulses. The resolution was found to deteriorate from 200 to 300 ps as the total voltage applied on the two MCPs increased from 1600 to 2000 V. This was likely due to a partial saturation of the MCP and/or the constant fraction discriminator working with signals beyond its optimum range of pulse width and shape. PMID:20687710

  14. Measurement of time resolution of thermoregulated SiPM for time of flight detectors

    NASA Astrophysics Data System (ADS)

    Cavazza, D.; D'Antone, I.; Foschi, E.; Guandalini, C.; Lax, I.; Levi, G.; Quadrani, L.; Sbarra, C.; Zuffa, M.

    2012-11-01

    Silicon Photomultipliers (SiPM) are considered very promising in many application where high timing performances, low cost, hardness to radiation damage and single photon counting are requested. Such applications go from astrophysics, high energy accelerator physics to medical physics. A group of SiPM from Hamamatsu has been tested with a low noise fast amplifier based on a hetero-junction FET, mounted on a proper front end board. A first telescope prototype has been used to test the electronics and results are shown. The SiPM time resolution has been measured to be σ∼30 ps, in agreement with other studies reported in literature. The SiPM gain depends critically on temperature and a thermoelectric module to control the circuit was also studied in order to use the system for space detectors.

  15. Single-Photon Detectors for Time-of-Flight Range Imaging

    NASA Astrophysics Data System (ADS)

    Stoppa, David; Simoni, Andrea

    We live in a three-dimensional (3D) world and thanks to the stereoscopic vision provided by our two eyes, in combination with the powerful neural network of the brain we are able to perceive the distance of the objects. Nevertheless, despite the huge market volume of digital cameras, solid-state image sensors can capture only a two-dimensional (2D) projection, of the scene under observation, losing a variable of paramount importance, i.e., the scene depth. On the contrary, 3D vision tools could offer amazing possibilities of improvement in many areas thanks to the increased accuracy and reliability of the models representing the environment. Among the great variety of distance measuring techniques and detection systems available, this chapter will treat only the emerging niche of solid-state, scannerless systems based on the TOF principle and using a detector SPAD-based pixels. The chapter is organized into three main parts. At first, TOF systems and measuring techniques will be described. In the second part, most meaningful sensor architectures for scannerless TOF distance measurements will be analyzed, focusing onto the circuital building blocks required by time-resolved image sensors. Finally, a performance summary is provided and a perspective view for the near future developments of SPAD-TOF sensors is given.

  16. Electronic Microchannel Plate Particle Detector Design for a CubeSat Time-of-Flight Reflectron Mass Spectrometer

    NASA Astrophysics Data System (ADS)

    Pyle, M. L.; Davidson, R.; Swenson, C.; Syrstad, E. A.

    2015-12-01

    Variations of gas density and composition in Earth's thermosphere and ionosphere are key indicators of interactions between different layers of Earth's atmosphere. The nature of interactions between neutral and ion species in the upper atmosphere is an active area of study in Heliophysics and there is much to learn about the dynamic relationship between the ionosphere and neutral thermosphere. Mass Spectrometers are among an array of instruments used to explore Earth's upper atmosphere and other space environments. Normally, these instruments are substantial in size and deployed on larger satellites. Data from these larger instruments generally provides information from a specific point in time at a single location. Studies of atmospheric density and composition with multiple locations for each time point could be performed by CubeSat swarms if proper instrumentation were available to fit CubeSat payload restrictions. The proposed miniaturized time-of-flight (TOF) mass spectrometer (MS) will have a mass resolution and range sufficient for measuring the composition of Earth's thermosphere and ionosphere while operating within the power and space constraints of a CubeSat. The capabilities of this instrument would potentially dramatically reduce the cost of future missions while simultaneously enhancing the science return. The design employs miniaturization of TOF-MS technology, including resolution refinement techniques used for larger instruments and standard concepts for TOF-MS components such as acceleration grids, a Bradbury-Nielsen wire gate, a gridless ion mirror, and microchannel plate detector (MCP). The quality of particle detection is known to have a significant impact on the instrument performance. A signal collector for an MCP detector is being designed to maximize the detection performance and enable the transmission of density and composition data back to Earth.

  17. A method for in situ absolute DD yield calibration of neutron time-of-flight detectors on OMEGA using CR-39-based proton detectors

    SciTech Connect

    Waugh, C. J.; Rosenberg, M. J.; Zylstra, A. B.; Frenje, J. A.; Seguin, F. H.; Petrasso, R. D.; Glebov, V. Yu.; Sangster, T. C.; Stoeckl, C.

    2015-05-27

    Neutron time of flight (nTOF) detectors are used routinely to measure the absolute DD neutron yield at OMEGA. To check the DD yield calibration of these detectors, originally calibrated using indium activation systems, which in turn were cross-calibrated to NOVA nTOF detectors in the early 1990s, a direct in situ calibration method using CR-39 range filter proton detectors has been successfully developed. By measuring DD neutron and proton yields from a series of exploding pusher implosions at OMEGA, a yield calibration coefficient of 1.09 ± 0.02 (relative to the previous coefficient) was determined for the 3m nTOF detector. In addition, comparison of these and other shots indicates that significant reduction in charged particle flux anisotropies is achieved when bang time occurs significantly (on the order of 500 ps) after the trailing edge of the laser pulse. This is an important observation as the main source of the yield calibration error is due to particle anisotropies caused by field effects. The results indicate that the CR-39-nTOF in situ calibration method can serve as a valuable technique for calibrating and reducing the uncertainty in the DD absolute yield calibration of nTOF detector systems on OMEGA, the National Ignition Facility, and laser megajoule.

  18. A method for in situ absolute DD yield calibration of neutron time-of-flight detectors on OMEGA using CR-39-based proton detectors

    DOE PAGESBeta

    Waugh, C. J.; Rosenberg, M. J.; Zylstra, A. B.; Frenje, J. A.; Seguin, F. H.; Petrasso, R. D.; Glebov, V. Yu.; Sangster, T. C.; Stoeckl, C.

    2015-05-27

    Neutron time of flight (nTOF) detectors are used routinely to measure the absolute DD neutron yield at OMEGA. To check the DD yield calibration of these detectors, originally calibrated using indium activation systems, which in turn were cross-calibrated to NOVA nTOF detectors in the early 1990s, a direct in situ calibration method using CR-39 range filter proton detectors has been successfully developed. By measuring DD neutron and proton yields from a series of exploding pusher implosions at OMEGA, a yield calibration coefficient of 1.09 ± 0.02 (relative to the previous coefficient) was determined for the 3m nTOF detector. In addition,more » comparison of these and other shots indicates that significant reduction in charged particle flux anisotropies is achieved when bang time occurs significantly (on the order of 500 ps) after the trailing edge of the laser pulse. This is an important observation as the main source of the yield calibration error is due to particle anisotropies caused by field effects. The results indicate that the CR-39-nTOF in situ calibration method can serve as a valuable technique for calibrating and reducing the uncertainty in the DD absolute yield calibration of nTOF detector systems on OMEGA, the National Ignition Facility, and laser megajoule.« less

  19. A method for in situ absolute DD yield calibration of neutron time-of-flight detectors on OMEGA using CR-39-based proton detectors

    SciTech Connect

    Waugh, C. J. Zylstra, A. B.; Frenje, J. A.; Séguin, F. H.; Petrasso, R. D.; Rosenberg, M. J.; Glebov, V. Yu.; Sangster, T. C.; Stoeckl, C.

    2015-05-15

    Neutron time of flight (nTOF) detectors are used routinely to measure the absolute DD neutron yield at OMEGA. To check the DD yield calibration of these detectors, originally calibrated using indium activation systems, which in turn were cross-calibrated to NOVA nTOF detectors in the early 1990s, a direct in situ calibration method using CR-39 range filter proton detectors has been successfully developed. By measuring DD neutron and proton yields from a series of exploding pusher implosions at OMEGA, a yield calibration coefficient of 1.09 ± 0.02 (relative to the previous coefficient) was determined for the 3m nTOF detector. In addition, comparison of these and other shots indicates that significant reduction in charged particle flux anisotropies is achieved when bang time occurs significantly (on the order of 500 ps) after the trailing edge of the laser pulse. This is an important observation as the main source of the yield calibration error is due to particle anisotropies caused by field effects. The results indicate that the CR-39-nTOF in situ calibration method can serve as a valuable technique for calibrating and reducing the uncertainty in the DD absolute yield calibration of nTOF detector systems on OMEGA, the National Ignition Facility, and laser megajoule.

  20. A method for in situ absolute DD yield calibration of neutron time-of-flight detectors on OMEGA using CR-39-based proton detectors.

    PubMed

    Waugh, C J; Rosenberg, M J; Zylstra, A B; Frenje, J A; Séguin, F H; Petrasso, R D; Glebov, V Yu; Sangster, T C; Stoeckl, C

    2015-05-01

    Neutron time of flight (nTOF) detectors are used routinely to measure the absolute DD neutron yield at OMEGA. To check the DD yield calibration of these detectors, originally calibrated using indium activation systems, which in turn were cross-calibrated to NOVA nTOF detectors in the early 1990s, a direct in situ calibration method using CR-39 range filter proton detectors has been successfully developed. By measuring DD neutron and proton yields from a series of exploding pusher implosions at OMEGA, a yield calibration coefficient of 1.09 ± 0.02 (relative to the previous coefficient) was determined for the 3m nTOF detector. In addition, comparison of these and other shots indicates that significant reduction in charged particle flux anisotropies is achieved when bang time occurs significantly (on the order of 500 ps) after the trailing edge of the laser pulse. This is an important observation as the main source of the yield calibration error is due to particle anisotropies caused by field effects. The results indicate that the CR-39-nTOF in situ calibration method can serve as a valuable technique for calibrating and reducing the uncertainty in the DD absolute yield calibration of nTOF detector systems on OMEGA, the National Ignition Facility, and laser megajoule. PMID:26026524

  1. A method for in situ absolute DD yield calibration of neutron time-of-flight detectors on OMEGA using CR-39-based proton detectors

    NASA Astrophysics Data System (ADS)

    Waugh, C. J.; Rosenberg, M. J.; Zylstra, A. B.; Frenje, J. A.; Séguin, F. H.; Petrasso, R. D.; Glebov, V. Yu.; Sangster, T. C.; Stoeckl, C.

    2015-05-01

    Neutron time of flight (nTOF) detectors are used routinely to measure the absolute DD neutron yield at OMEGA. To check the DD yield calibration of these detectors, originally calibrated using indium activation systems, which in turn were cross-calibrated to NOVA nTOF detectors in the early 1990s, a direct in situ calibration method using CR-39 range filter proton detectors has been successfully developed. By measuring DD neutron and proton yields from a series of exploding pusher implosions at OMEGA, a yield calibration coefficient of 1.09 ± 0.02 (relative to the previous coefficient) was determined for the 3m nTOF detector. In addition, comparison of these and other shots indicates that significant reduction in charged particle flux anisotropies is achieved when bang time occurs significantly (on the order of 500 ps) after the trailing edge of the laser pulse. This is an important observation as the main source of the yield calibration error is due to particle anisotropies caused by field effects. The results indicate that the CR-39-nTOF in situ calibration method can serve as a valuable technique for calibrating and reducing the uncertainty in the DD absolute yield calibration of nTOF detector systems on OMEGA, the National Ignition Facility, and laser megajoule.

  2. A novel method for modeling the neutron time of flight detector response in current mode to inertial confinement fusion experiments (invited)

    SciTech Connect

    Nelson, A. J.; Cooper, G. W.; Ruiz, C. L.; Chandler, G. A.; Fehl, D. L.; Hahn, K. D.; Leeper, R. J.; Smelser, R.; Torres, J. A.

    2012-10-15

    A novel method for modeling the neutron time of flight (nTOF) detector response in current mode for inertial confinement fusion experiments has been applied to the on-axis nTOF detectors located in the basement of the Z-Facility. It will be shown that this method can identify sources of neutron scattering, and is useful for predicting detector responses in future experimental configurations, and for identifying potential sources of neutron scattering when experimental set-ups change. This method can also provide insight on how much broadening neutron scattering contributes to the primary signals, which is then subtracted from them. Detector time responses are deconvolved from the signals, allowing a transformation from dN/dt to dN/dE, extracting neutron spectra at each detector location; these spectra are proportional to the absolute yield.

  3. The Silicon Drift Detector of the ALICE Experiment

    SciTech Connect

    Batigne, G.

    2005-10-12

    The ALICE experiment studies the properties of quark-gluon plasma and requires a good tracking system. This document presents the silicon drift detector which is part of the Inner Tracking System. Its principle and main features are given, especially its sensitivity to temperature variation and the effect of parasitic fields on measurement. Finally, the typical spatial resolution of this detector, which has been measured during beam tests, is shown.

  4. Readout strategy of an electro-optical coupled PET detector for time-of-flight PET/MRI.

    PubMed

    Bieniosek, M F; Olcott, P D; Levin, C S

    2013-10-21

    Combining PET with MRI in a single system provides clinicians with complementary molecular and anatomical information. However, existing integrated PET/MRI systems do not have time-of-flight (ToF) PET capabilities. This work describes an MRI-compatible front-end electronic system with ToF capabilities. The approach employs a fast arrival-time pickoff comparator to digitize the timing information, and a laser diode to drive a 10 m fiber-optic cable to optically transmit asynchronous timing information to a photodiode receiver readout system. The FWHM jitter of the comparator and this electo-optical link is 11.5 ps in response to a fast digital pulse. When configured with LYSO scintillation crystals and Hamamatsu MPPC silicon photo-multipliers the comparator and electro-optical link achieved a 511 keV coincidence time resolution of 254.7 ps +/- 8.0 ps FWHM with 3 × 3 × 20 mm(3) crystals and 166.5 +/- 2.5 ps FWHM with 3 × 3 × 5 mm(3) crystals. PMID:24061218

  5. Readout Strategy of an Electro-optical Coupled PET Detector for Time-of-Flight PET/MRI

    PubMed Central

    Bieniosek, M F; Olcott, P D; Levin, C S

    2013-01-01

    Combining PET with MRI in a single system provides clinicians with complementary molecular and anatomical information. However, existing integrated PET/MRI systems do not have time-of-flight PET capabilities. This work describes an MRI-compatible front-end electronic system with ToF capabilities. The approach employs a fast arrival-time pickoff comparator to digitize the timing information, and a laser diode to drive a 10m fiber-optic cable to optically transmit asynchronous timing information to a photodiode receiver readout system. The comparator and this electo-optical link show a combined 11.5ps fwhm jitter in response to a fast digital pulse. When configured with LYSO scintillation crystals and Hamamatsu MPPC silicon photo-multipliers the comparator and electro-optical link achieved a 511keV coincidence time resolution of 254.7ps +/− 8.0ps fwhm with 3×3×20mm crystals and 166.5 +/− 2.5ps fwhm with 3×3×5mm crystals. PMID:24061218

  6. Monte Carlo Simulation Study on the Time Resolution of a PMT-Quadrant-Sharing LSO Detector Block for Time-of-Flight PET.

    PubMed

    Liu, Shitao; Li, Hongdi; Zhang, Yuxuan; Ramirez, Rocio A; Baghaei, Hossain; An, Shaohui; Wang, Chao; Liu, Jiguo; Wong, Wai-Hoi

    2009-01-01

    We developed a detailed Monte Carlo simulation method to study the time resolution of detectors for time-of-flight positron emission tomography (TOF PET). The process of gamma ray interaction in detectors, scintillation light emission and transport inside the detectors, the photoelectron generation and anode signal generation in the photomultiplier tube (PMT), and the electronics process of discriminator are simulated. We tested this simulation method using published experimental data, and found that it can generate reliable results. Using this method, we simulated the time resolution for a 13 × 13 detector block of 4 × 4 × 20 mm(3) lutetium orthosilicate (LSO) crystals coupled to four 2-inch PMTs using PMT-quadrant-sharing (PQS) technology. We analyzed the effects of several factors, including the number of photoelectrons, light transport, transit time spread (TTS), and the depth of interaction (DOI). The simulation results indicated that system time resolution of 360 ps should be possible with currently available fast PMTs. This simulation method can also be used to simulate the time resolution of other detector design method. PMID:20559457

  7. Efficiency and rate capability studies of the time-of-flight detector for isochronous mass measurements of stored short-lived nuclei with the FRS-ESR facility

    NASA Astrophysics Data System (ADS)

    Kuzminchuk-Feuerstein, Natalia; Fabian, Benjamin; Diwisch, Marcel; Plaß, Wolfgang R.; Geissel, Hans; Ayet San Andrés, Samuel; Dickel, Timo; Knöbel, Ronja; Scheidenberger, Christoph; Sun, Baohua; Weick, Helmut

    2016-06-01

    A time-of-flight (TOF) detector is used for Isochronous Mass Spectrometry (IMS) with the projectile fragment separator FRS and the heavy-ion storage ring ESR. Exotic nuclei are spatially separated in flight with the FRS at about 70% of the speed of light and are injected into the ESR. The revolution times of the stored ions circulating in the ESR are measured with a thin transmission foil detector. When the ions penetrate the thin detector foil, secondary electrons (SEs) are emitted from the surface and provide the timing information in combination with microchannel plate (MCP) detectors. The isochronous transport of the SEs is performed by perpendicular superimposed electric and magnetic fields. The detection efficiency and the rate capability of the TOF detector have been studied in simulations and experiments. As a result the performance of the TOF detector has been improved substantially: (i) The SE collection efficiency was doubled by use of an optimized set of electric and magnetic field values; now SEs from almost the full area of the foil are transmitted to the MCP detectors. (ii) The rate capability of the TOF detector was improved by a factor of four by the use of MCPs with 5 μm pore size. (iii) With these MCPs and a carbon foil with a reduced thickness of 10 μg/cm2 the number of recorded revolutions in the ESR has been increased by nearly a factor of 10. The number of recorded revolutions determine the precision of the IMS experiments. Heavy-ion measurements were performed with neon ions at 322 MeV/u and uranium fission fragments at about 370 MeV/u. In addition, measurements with an alpha source were performed in the laboratory with a duplicate of the TOF detector.

  8. Experiences and evolutions of the ALICE DAQ Detector Algorithms framework

    NASA Astrophysics Data System (ADS)

    Chapeland, Sylvain; Carena, Franco; Carena, Wisla; Chibante Barroso, Vasco; Costa, Filippo; Denes, Ervin; Divia, Roberto; Fuchs, Ulrich; Grigore, Alexandru; Simonetti, Giuseppe; Soos, Csaba; Telesca, Adriana; Vande Vyvre, Pierre; von Haller, Barthelemy

    2012-12-01

    ALICE (A Large Ion Collider Experiment) is the heavy-ion detector studying the physics of strongly interacting matter and the quark-gluon plasma at the CERN LHC (Large Hadron Collider). The 18 ALICE sub-detectors are regularly calibrated in order to achieve most accurate physics measurements. Some of these procedures are done online in the DAQ (Data Acquisition System) so that calibration results can be directly used for detector electronics configuration before physics data taking, at run time for online event monitoring, and offline for data analysis. A framework was designed to collect statistics and compute calibration parameters, and has been used in production since 2008. This paper focuses on the recent features developed to benefit from the multi-cores architecture of CPUs, and to optimize the processing power available for the calibration tasks. It involves some C++ base classes to effectively implement detector specific code, with independent processing of events in parallel threads and aggregation of partial results. The Detector Algorithm (DA) framework provides utility interfaces for handling of input and output (configuration, monitored physics data, results, logging), and self-documentation of the produced executable. New algorithms are created quickly by inheritance of base functionality and implementation of few ad-hoc virtual members, while the framework features are kept expandable thanks to the isolation of the detector calibration code. The DA control system also handles unexpected processes behaviour, logs execution status, and collects performance statistics.

  9. Note: A large open ratio, time, and position sensitive detector for time of flight measurements in UHV

    SciTech Connect

    Lupone, S.; Damoy, S.; Husseen, A.; Briand, N.; Debiossac, M.; Tall, S.; Roncin, P.

    2015-12-15

    We report on the construction of an UHV compatible 40 mm active diameter detector based on micro channel plates and assembled directly on the feed-throughs of a DN63CF flange. It is based on the charge division technique and uses a standard 2 inch Si wafer as a collector. The front end electronic is placed directly on the air side of the flange allowing excellent immunity to noise and a very good timing signal with reduced ringing. The important aberrations are corrected empirically providing an absolute positioning accuracy of 500 μm while a 150 μm resolution is measured in the center.

  10. Monolithic single-photon detectors and time-to-digital converters for picoseconds time-of-flight ranging

    NASA Astrophysics Data System (ADS)

    Markovic, Bojan; Tisa, Simone; Tosi, Alberto; Zappa, Franco

    2011-03-01

    We present a novel "smart-pixel" able to measure and record in-pixel the time delay (photon timing) between a START (e.g. given by laser excitation, cell stimulus, or LIDAR flash) and a STOP (e.g. arrival of the first returning photon from the fluorescence decay signal or back reflection from an object). Such smart-pixel relies of a SPAD detector and a Timeto- Digital Converter monolithically designed and manufactured in the same chip. Many pixels can be laid out in a rows by columns architecture, to give birth to expandable 2D imaging arrays for picoseconds-level single-photon timing applications. Distance measurements, by means of direct TOF detection (used in LIDAR systems) provided by each pixel, can open the way to the fabrication of single-chip 3D ranging arrays for scene reconstruction and intelligent object recognition. We report on the design and characterization of prototype circuits, fabricated in a 0.35 μm standard CMOS technology containing complete conversion channels, "smart-pixel" and ancillary electronics with 20 μm active area diameter SPAD detector and related quenching circuitry. With a 100 MHz reference clock, the TDC provides timeresolution of 10 ps, dynamic range of 160 ns and very high conversion linearity.

  11. Development of large area diamond detectors for time-of-flight measurements of relativistic heavy ions for the super-FRS

    NASA Astrophysics Data System (ADS)

    Schirru, F.; Nociforo, C.; Kiš, M.; Ciobanu, M.; Frühauf, J.; Kratz, A.; Kurz, N.; Szczepanczyk, B.; Träger, M.; Visinka, R.

    2016-06-01

    Time-of-flight (ToF) performances of large area diamond detectors based on polycrystalline samples of dimensions 20 mm  ×  20 mm and thickness of 0.3 mm are presented. The devices that feature segmented Cr/Au electrodes in a sandwich configuration were irradiated with a heavy ions 197Au beam of 1 GeV u‑1 showing, when mounted with a separation distance of 2 cm, a ToF resolution \\barσ of 37.5 ps averaged on 16 strip pairs. When ToF measurements were performed over a particle path of 30 m, a resolution σ of 45 ps was achieved. The detectors were mounted on high-vacuum compatible printed circuit boards (PCBs) with integrated processing electronics. This is the first time that ToF measurements have been performed using integrated electronics with such a large separation distance between the diamond detectors.

  12. Time resolution of time-of-flight detector based on multiple scintillation counters readout by SiPMs

    NASA Astrophysics Data System (ADS)

    Cattaneo, P. W.; De Gerone, M.; Gatti, F.; Nishimura, M.; Ootani, W.; Rossella, M.; Shirabe, S.; Uchiyama, Y.

    2016-08-01

    A new timing detector measuring ∼ 50 MeV / c positrons is under development for the MEG II experiment, aiming at a time resolution σt ∼ 30 ps. The resolution is expected to be achieved by measuring each positron time with multiple counters made of plastic scintillator readout by silicon photomultipliers (SiPMs). The purpose of this work is to demonstrate the time resolution for ∼ 50 MeV / c positrons using prototype counters. Counters with dimensions of 90 × 40 × 5mm3 readout by six SiPMs (three on each 40 × 5mm2 plane) were built with SiPMs from Hamamatsu Photonics and AdvanSiD and tested in a positron beam at the DAΦNE Beam Test Facility. The time resolution was found to improve nearly as the square root of the number of counter hits. A time resolution σt = 26.2 ± 1.3 ps was obtained with eight counters with Hamamatsu SiPMs. These results suggest that the design resolution is achievable in the MEG II experiment.

  13. A novel method for the line-of-response and time-of-flight reconstruction in TOF-PET detectors based on a library of synchronized model signals

    NASA Astrophysics Data System (ADS)

    Moskal, P.; Zoń, N.; Bednarski, T.; Białas, P.; Czerwiński, E.; Gajos, A.; Kamińska, D.; Kapłon, Ł.; Kochanowski, A.; Korcyl, G.; Kowal, J.; Kowalski, P.; Kozik, T.; Krzemień, W.; Kubicz, E.; Niedźwiecki, Sz.; Pałka, M.; Raczyński, L.; Rudy, Z.; Rundel, O.; Salabura, P.; Sharma, N. G.; Silarski, M.; Słomski, A.; Smyrski, J.; Strzelecki, A.; Wieczorek, A.; Wiślicki, W.; Zieliński, M.

    2015-03-01

    A novel method of hit time and hit position reconstruction in scintillator detectors is described. The method is based on comparison of detector signals with results stored in a library of synchronized model signals registered for a set of well-defined positions of scintillation points. The hit position is reconstructed as the one corresponding to the signal from the library which is most similar to the measurement signal. The time of the interaction is determined as a relative time between the measured signal and the most similar one in the library. A degree of similarity of measured and model signals is defined as the distance between points representing the measurement- and model-signal in the multi-dimensional measurement space. Novelty of the method lies also in the proposed way of synchronization of model signals enabling direct determination of the difference between time-of-flights (TOF) of annihilation quanta from the annihilation point to the detectors. The introduced method was validated using experimental data obtained by means of the double strip prototype of the J-PET detector and 22Na sodium isotope as a source of annihilation gamma quanta. The detector was built out from plastic scintillator strips with dimensions of 5 mm×19 mm×300 mm, optically connected at both sides to photomultipliers, from which signals were sampled by means of the Serial Data Analyzer. Using the introduced method, the spatial and TOF resolution of about 1.3 cm (σ) and 125 ps (σ) were established, respectively.

  14. Performance of timing RPC detectors for relativistic ions and design of a time-of-flight detector (iToF) for the R3B-FAIR experiment for fission and spallation reactions

    SciTech Connect

    Casarejos, E.; Ayyad, Y.; Benlliure, J.; Duran, I.; Paradela, C.; Lopez-Lago, M.; Segade, A.; Vilan, J. A.

    2011-07-01

    Resistive-plate-chambers (RPCs) were proposed to be used to build a time-of-flight detector for relativist heavy ions of the R3B-FAIR experiment, as well as other applications. State-of-the-art reaction codes allow for evaluating the requirements of the detector. The specific needs that working with heavy ions impose about material thicknesses are solved with new design concepts. We built prototypes and investigated the behaviour of RPCs tested with relativistic heavy ions. We measured the efficiency and streamer presence for ions with atomic numbers up to 38. Electron beams were used to study the timing capabilities of the prototypes. (authors)

  15. Demonstration of single-flux-quantum readout circuits for time-of-flight mass spectrometry systems using superconducting strip ion detectors

    NASA Astrophysics Data System (ADS)

    Sano, Kyosuke; Takahashi, Yoshihiro; Yamanashi, Yuki; Yoshikawa, Nobuyuki; Zen, Nobuyuki; Ohkubo, Masataka

    2015-07-01

    We have been developing a superconducting time-of-flight mass spectrometry (TOF-MS) system that consists of a superconducting strip ion detector (SSID) and a single-flux-quantum (SFQ) time-to-digital converter. In this study, we implement a prototype TOF-MS system using an SSID and an SFQ readout circuit in which output signals from the SSID are read out by the SFQ readout circuit and output to room-temperature electronics. The SFQ readout circuit, which consists of a current discriminator, a Josephson transmission line and an SFQ/dc converter, was fabricated using the AIST Nb standard process (STP2), and installed in a 4.2 K cryostat with a meander-shaped NbN SSID measuring 200 μm square. The dark count rate for the SSID was measured as increasing exponentially with the increase in the bias current of the SSID by using the SFQ readout circuit. Mass spectrum measurements of biomolecules, Angiotensin I, which has a molecular weight of 1296 Da, were demonstrated by using the matrix-assisted laser desorption/ionization method, and a clear corresponding peak was observed in the mass spectrum.

  16. A novel method for modeling the neutron time of flight (nTOF) detector response in current mode to inertial confinement fusion experiments.

    SciTech Connect

    Nelson, Alan J.; Cooper, Gary Wayne; Ruiz, Carlos L.; Chandler, Gordon Andrew; Fehl, David Lee; Hahn, Kelly Denise; Leeper, Ramon Joe; Smelser, Ruth Marie; Torres, Jose A.

    2013-09-01

    There are several machines in this country that produce short bursts of neutrons for various applications. A few examples are the Zmachine, operated by Sandia National Laboratories in Albuquerque, NM; the OMEGA Laser Facility at the University of Rochester in Rochester, NY; and the National Ignition Facility (NIF) operated by the Department of Energy at Lawrence Livermore National Laboratory in Livermore, California. They all incorporate neutron time of flight (nTOF) detectors which measure neutron yield, and the shapes of the waveforms from these detectors contain germane information about the plasma conditions that produce the neutrons. However, the signals can also be %E2%80%9Cclouded%E2%80%9D by a certain fraction of neutrons that scatter off structural components and also arrive at the detectors, thereby making analysis of the plasma conditions more difficult. These detectors operate in current mode - i.e., they have no discrimination, and all the photomultiplier anode charges are integrated rather than counted individually as they are in single event counting. Up to now, there has not been a method for modeling an nTOF detector operating in current mode. MCNPPoliMiwas developed in 2002 to simulate neutron and gammaray detection in a plastic scintillator, which produces a collision data output table about each neutron and photon interaction occurring within the scintillator; however, the postprocessing code which accompanies MCNPPoliMi assumes a detector operating in singleevent counting mode and not current mode. Therefore, the idea for this work had been born: could a new postprocessing code be written to simulate an nTOF detector operating in current mode? And if so, could this process be used to address such issues as the impact of neutron scattering on the primary signal? Also, could it possibly even identify sources of scattering (i.e., structural materials) that

  17. Managing operational documentation in the ALICE Detector Control System

    NASA Astrophysics Data System (ADS)

    Lechman, M.; Augustinus, A.; Bond, P.; Chochula, P.; Kurepin, A.; Pinazza, O.; Rosinsky, P.

    2012-12-01

    ALICE (A Large Ion Collider Experiment) is one of the big LHC (Large Hadron Collider) experiments at CERN in Geneve, Switzerland. The experiment is composed of 18 sub-detectors controlled by an integrated Detector Control System (DCS) that is implemented using the commercial SCADA package PVSSII. The DCS includes over 1200 network devices, over 1,000,000 monitored parameters and numerous custom made software components that are prepared by over 100 developers from all around the world. This complex system is controlled by a single operator via a central user interface. One of his/her main tasks is the recovery of anomalies and errors that may occur during operation. Therefore, clear, complete and easily accessible documentation is essential to guide the shifter through the expert interfaces of different subsystems. This paper describes the idea of the management of the operational documentation in ALICE using a generic repository that is built on a relational database and is integrated with the control system. The experience gained and the conclusions drawn from the project are also presented.

  18. Time of flight mass spectrometer

    DOEpatents

    Ulbricht, Jr., William H.

    1984-01-01

    A time-of-flight mass spectrometer is described in which ions are desorbed from a sample by nuclear fission fragments, such that desorption occurs at the surface of the sample impinged upon by the fission fragments. This configuration allows for the sample to be of any thickness, and eliminates the need for complicated sample preparation.

  19. Performance of the High Momentum Particle Identification Detector in ALICE at Lhc

    NASA Astrophysics Data System (ADS)

    de Cataldo, Giacinto

    2008-06-01

    The ALICE High Momentum Particle Identification Detector (HMPID) is a proximity focusing ring imaging Cherenkov detector (RICH), 10 m2 of active area for the hadron identification at high transverse momenta: 1 < pt < 3 GeV/c for charged π and K, 1 < pt < 5 GeV/c for p. It has been installed in ALICE since September 2006 in view of the first collisions expected mid-2008. After a short description of the detector and the online data quality monitoring this paper focuses on the HMPID particle identification (PID) capabilities even in the higher expected track multiplicity dNch/dη = 6000, simulated in central Pb-Pb ALICE events.

  20. Readout system of the ALICE Muon tracking detector

    NASA Astrophysics Data System (ADS)

    Rousseau, Sylvain

    2010-11-01

    A Large Ion Collider Experiment (ALICE) will be aimed at studying heavy ion collisions at the extreme energy densities accessible at the CERN's Large Hadron Collider (LHC), where the formation of the Quark Gluon Plasma is expected. The ALICE muon forward spectrometer will identify muons with momentum above 4 GeV/c, allowing the study of quarkonia and heavy flavors in the pseudorapidity range -4.0< η<-2.5 with 2 π azimuthal coverage. The muon tracking system consists of 10 Cathode Pad Chambers (CPC) with 1.1 million of pads that represent the total number of acquisition channels to manage. In this article, we will give an overview of the ALICE Muon Spectrometer. Afterward, we will focus on tracking system Front end Electronics (FEE) and readout system. We will show that the Digital Signal Processor (DSP) architecture fulfills all the requirements, including radiation hardness against neutrons. Finally, real-time performances are discussed.

  1. Readout electronics upgrade on ALICE/PHOS detector for Run 2 of LHC

    NASA Astrophysics Data System (ADS)

    Wang, D.; Zhang, F.; Feng, W.; Huang, G.; Song, Z.; Yin, Z.; Zhou, D.

    2015-02-01

    The ALICE/PHOS detector is carrying out a major upgrade of its readout electronics for the RUN 2 of LHC (2015-2017). A new architecture based on the point to point link is developed. The event readout rate can achieve 30 kHz by replacing the old parallel GTL bus with DTC links. The communication stability of the interface between front-end electronic boards and readout concentrators is significantly improved. A new FPGA firmware is designed to be compatible with the upgraded ALICE trigger system and DATE software.

  2. R&D on a Detector for Very High Momentum Charged Hadron Identification in ALICE

    NASA Astrophysics Data System (ADS)

    Gallas, A.

    2006-04-01

    The latest theoretical and experimental results from experiments at RHIC suggest investigating a physics domain in heavy ion collisions for pt higher than the one planned to be covered at present by the Particle Identification (PID) system of the ALICE experiment. We present here a possible upgrade of the High Momentum Particle Identification Detector (HMPID) based on the idea of the Threshold Imaging Cherenkov (TIC) detector operated for the first time by the NA44 experiment.

  3. Simulations on time-of-flight ERDA spectrometer performance.

    PubMed

    Julin, Jaakko; Arstila, Kai; Sajavaara, Timo

    2016-08-01

    The performance of a time-of-flight spectrometer consisting of two timing detectors and an ionization chamber energy detector has been studied using Monte Carlo simulations for the recoil creation and ion transport in the sample and detectors. The ionization chamber pulses have been calculated using Shockley-Ramo theorem and the pulse processing of a digitizing data acquisition setup has been modeled. Complete time-of-flight-energy histograms were simulated under realistic experimental conditions. The simulations were used to study instrumentation related effects in coincidence timing and position sensitivity, such as background in time-of-flight-energy histograms. Corresponding measurements were made and simulated results are compared with data collected using the digitizing setup. PMID:27587115

  4. Event Plane Resolution Simulations for The Fast Interaction Trigger Detector of ALICE at the LHC

    NASA Astrophysics Data System (ADS)

    Sulaimon, Isiaka; Harton, Austin; Garcia, Edmundo; Alice-Fit Collaboration

    2016-03-01

    CERN (European Center for Nuclear Research) is a global laboratory that studies proton and heavy ion collisions at the Large Hadron Collider (LHC). ALICE (A Large Ion Collider Experiment) is one of four large experiments of the LHC. ALICE is dedicated to the study of the transition of matter to Quark Gluon Plasma in heavy ion collisions. In the present ALICE detector there are two sub-detectors, (the T0 and V0), that provide minimum bias trigger, multiplicity trigger, beam-gas event rejection, collision time for other sub detectors, on line multiplicity and event plane determination. In order to adapt these functionalities to the collision rates expected for the LHC upgrade after 2020, it is planned to replace these systems by a single detector system, called the Fast Interaction Trigger (FIT). In this presentation we describe the performance parameters of the FIT upgrade; show the proposed characteristics of the T0-Plus and the simulations that support the conceptual design of this detector. In particular we describe the performance simulations of the event plane resolution. This material is based upon work supported by the National Science Foundation under Grants NSF-PHY-0968903 and NSF-PHY-1305280.

  5. Time-of-flight measurements

    SciTech Connect

    Atwood, W.B.

    1980-10-01

    Time of flight (TOF) measurements are used in high energy particle physics experiments to: (1) distinguish background from events and (2) identify particle types. An example of background separation is shown. These data come from a coincidence electro-production experiment performed at SLAC. The reaction being studied was e + p ..-->.. e' + p' + X where the e(p) stand for an initial and detected electron (proton) and X is a produced but undetected final state with a mass in the rho meson region. The relative time between the detection of an electron and a proton in two of the spectrometers in End Station A is plotted. Data for two different kinematic settings taken in the experiment are shown. The time resolution has been partially corrected for the various flight paths through the instruments and the difference in time resolutions between the two settings results mainly from the incompleteness of this correction. The signal height above the background depends on the time resolution, ..delta.. tau. The chance background is proportional to the product of the electron counting rate, the proton counting rate, and ..delta.. tau. Smaller ..delta.. tau means that higher electron and proton counting rates may be tolerated and result in a similar signal-to-noise ratio.

  6. Development of a 10 picosecond time-of-flight Counter

    SciTech Connect

    Brandt, Andrew G

    2010-03-18

    This Advanced Detector Research proposal presented a plan to develop an extremely fast time-of-flight detector for measuring the arrival time of beam protons scattered at small angles in high energy hadron colliders, such as the Large Hadron Collider (LHC). The proposed detectors employ a gas or quartz Cerenkov radiator which produce light when a proton passes through them, coupled to a micro-channel plate photomultiplier tube (MCP-PMT) that converts the light to an electrical pulse. The very small jitter of the pulse time provided by the MCP-PMT, combined with downstream electronics that accurately measure the pulse time results in a time-of-flight measurement of unprecedented accuracy. This ADR proposal was extremely successful, culminating in the development of a 10 ps resolution time-of-flight system, about an order of magnitude better than any time-of-flight system previously deployed at a collider experiment. The primary areas of advance were the usage of new radiator geometries providing fast detector signals, using multiple measurements to obtain a superior system resolution, and development of an electronics readout system tuned to maintain the excellent timing afforded by the detector. Test beam and laser tests have improved the knowledge of MCP-PMT’s and enabled the evaluation of the new detector concepts. In addition to being a generally useful detector concept, these fast timing detectors are a major component of proposed upgrades to the LHC ATLAS and CMS detectors, and if deployed could significantly enhance the discovery potential of these detectors, including contributions to the measurement of the properties of the Higgs Boson. In addition to the potential for furthering fundamental understanding of nature, the knowledge gained on MCP-PMT’s could be useful in developing improved versions of these devices which have promise in diverse fields such as biological and medical imaging.

  7. Evaluation of a pulsed glow discharge time-of-flight mass spectrometer as a detector for gas chromatography and the influence of the glow discharge source parameters on the information volume in chemical speciation analysis.

    PubMed

    Fliegel, Daniel; Fuhrer, Katrin; Gonin, Marc; Günther, Detlef

    2006-09-01

    The figures of merit of a pulsed glow discharge time-of-flight mass spectrometer (GD-TOFMS) as a detector for gas chromatography (GC) analysis were evaluated. The mass resolution for the GD-TOFMS was determined on FWHM in the high mass range (208Pb+) as high as 5,500. Precision of 400 subsequent analyses was calculated on 63Cu+ to be better than 1% RSD with no significant drift over the time of the analysis. Isotope precision based on the 63Cu+/65Cu+ ratio over 400 analyses was 1.5% RSD. The limits of detection for gaseous analytes (toluene in methanol as solvent) were determined to be as low as several hundred ppb or several hundred pg absolute without using any pre-concentration technique. Furthermore, the different GD source parameters like capillary distance, cathode-anode spacing, and GD source pressure with regards to the accessible elemental, structural, and molecular information were evaluated. It was demonstrated that each of these parameters has severe influence on the ratio of elemental, structural, and parent molecular information in chemical speciation analysis. PMID:16773303

  8. A Very High Momentum Particle Identification Detector for the ALICE experiment

    SciTech Connect

    Mayani, Daniel

    2011-04-26

    The main purpose of the ALICE experiment at CERN is to identify and study the quark-gluon plasma (QGP) in heavy ion collisions at the LHC. Among others, hadrochemistry allows for a detailed insight into the characteristics of the high temperature and density system created in these events. It is therefore important to be able to identify charged particles on a track by track basis. Moreover, results from high energy nucleus-nucleus collisions obtained by other experiments (e.g. at RHIC) indicate that it is imperative to extend the detection capability of ALICE to higher momenta. To meet these challenges, we propose the construction of the Very High Momentum Particle Identification Detector (VHMPID), which aims to identify charged pions, kaons, protons and antiprotons in the momentum range of 10 GeV/cdetector proposal based on a RICH (Ring Imaging Cherenkov) detector with a C{sub 4}F{sub 10} radiator and a MWPC based CsI photon counter. In addition, we will present the advances in the development of an alternative multi-THGEM based CsI photon detector.

  9. Jet-underlying event studies with ALICE detector at the LHC

    NASA Astrophysics Data System (ADS)

    Abelev, Betty

    2011-10-01

    Relativistic heavy ion collisions produce a state of strongly interacting matter of quarks and gluons, called the Quark Gluon Plasma (QGP). Measuring particle production via fragmentation (specifically in jets) and understanding parton energy loss in the QGP enables one to directly probe the medium. One of the necessary components in studying jets in heavy ion events is the ability to isolate jets from the soft physics background, i.e., the underlying event. Thus it is important to understand the underlying event properties, in particular, energy fluctuations. This presentation will address the initial studies done to map out the underlying event in √{ s} = 7 TeV pp collisions measured with the ALICE detector at the LHC, as preparation for extending these studies to Pb-Pb collisions. The focus will be on the analyses performed with the ALICE Electro-Magnetic Calorimeter (EMCal). EMCal is especially well-suited for the measurement of high-momentum particles which are produced predominantly in jets and therefore is a useful tool in subtracting the jet cone from the underlying event. For the ALICE Collaboration.

  10. Quantitative analysis of nitrogen containing compounds in microalgae based bio-oils using comprehensive two-dimensional gas-chromatography coupled to nitrogen chemiluminescence detector and time of flight mass spectrometer.

    PubMed

    Toraman, Hilal E; Franz, Kristina; Ronsse, Frederik; Van Geem, Kevin M; Marin, Guy B

    2016-08-19

    Insight in the composition of the algae derived bio-oils is crucial for the development of efficient conversion processes and better upgrading strategies for microalgae. Comprehensive two-dimensional gas chromatography (GC×GC) coupled to nitrogen chemiluminescence detector (NCD) and time-of-flight mass spectrometer (TOF-MS) allows to obtain the detailed quantitative composition of the nitrogen containing compounds in the aqueous and the organic fraction of fast pyrolysis bio-oils from microalgae. Normal phase (apolar×mid-polar) and reverse phase column (polar×apolar) combination are investigated to optimize the separation of the detected nitrogen containing compounds. The reverse phase column combination gives the most detailed information in terms of the nitrogen containing compounds. The combined information from the GC×GC-TOF-MS (qualitative) and GC×GC-NCD (quantitative) with the use of a well-chosen internal standard, i.e. caprolactam, enables the identification and quantification of nitrogen containing compounds belonging to 13 different classes: amines, imidazoles, amides, imides, nitriles, pyrazines, pyridines, indoles, pyrazoles, pyrimidines, quinolines, pyrimidinediones and other nitrogen containing compounds which were not assigned to a specific class. The aqueous fraction mostly consists of amines (4.0wt%) and imidazoles (2.8wt%) corresponding to approximately 80wt% of the total identified nitrogen containing compounds. On the other hand, the organic fraction shows a more diverse distribution of nitrogen containing compounds with the majority of the compounds quantified as amides (3.0wt%), indoles (2.0wt%), amines (1.7wt%) and imides (1.3wt%) corresponding to approximately 65wt% of the total identified nitrogen containing compounds. PMID:27432785

  11. Inexpensive Time-of-Flight Velocity Measurements.

    ERIC Educational Resources Information Center

    Everett, Glen E.; Wild, R. L.

    1979-01-01

    Describes a circuit designed to measure time-of-flight velocity and shows how to use it to determine bullet velocity in connection with the ballistic pendulum demonstration of momentum conservation. (Author/GA)

  12. ALICE electromagnetic calorimeter prototype test

    SciTech Connect

    Awes, Terry; /Oak Ridge

    2005-09-01

    individually read out towers. The fibers from an individual tower are grouped together to form readout tower bundles. These are each optically coupled to an avalanche photodiode (APO) via a short light guide to provide some spatial optical mixing and to match the fiber bundle to the APO. The module assembly is indicated in Figure l. The supermodules weigh about 9.6 tons and are the basic units handled during installation. Each supermodule is roughly I45cm wide at the front surface by 350cm long with an active depth of 24.5cm (at {eta} = 0) plus an additional 6.6 cm of depth in structural plates. The physical characteristics of the ALICE EMCal are summarized in Table 1. The EMCal test beam measurements at FNAL will utilize a stacked 4 x 4 array of prototype EMCal modules (8 x 8 towers). All towers will be instrumented with the same model APO and preamplifier as will be used in the ALICE experiment and all channels will be readout with existing prototype front end electronics intended for use in ALICE. The goals of the test beam measurements are: To investigate the energy resolution, linearity, uniformity, and position resolution, using electron beams; To study the energy dependence of the response to electrons and hadrons to determine the particle identification capabilities of the EMCal by shower shape; And to investigate the timing characteristics of the energy signal for crude time-of-flight measurement ({approx} 1ns) for use for anti-neutron rejection. Measurements will be made for comparison with different signal shaping times in the front end electronics.

  13. Time-of-flight radio location system

    DOEpatents

    McEwan, Thomas E.

    1996-01-01

    A bi-static radar configuration measures the direct time-of-flight of a transmitted RF pulse and is capable of measuring this time-of-flight with a jitter on the order of about one pico-second, or about 0.01 inch of free space distance for an electromagnetic pulse over a range of about one to ten feet. A transmitter transmits a sequence of electromagnetic pulses in response to a transmit timing signal, and a receiver samples the sequence of electromagnetic pulses with controlled timing in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the sequence of electromagnetic pulses such that the time between transmission of pulses in the sequence and sampling by the receiver sweeps over a range of delays. The receive timing signal sweeps over the range of delays in a sweep cycle such that pulses in the sequence are sampled at the pulse repetition rate, and with different delays in the range of delays to produce a sample signal representing magnitude of a received pulse in equivalent time. Automatic gain control circuitry in the receiver controls the magnitude of the equivalent time sample signal. A signal processor analyzes the sample signal to indicate the time-of-flight of the electromagnetic pulses in the sequence.

  14. Time-of-flight radio location system

    DOEpatents

    McEwan, T.E.

    1996-04-23

    A bi-static radar configuration measures the direct time-of-flight of a transmitted RF pulse and is capable of measuring this time-of-flight with a jitter on the order of about one pico-second, or about 0.01 inch of free space distance for an electromagnetic pulse over a range of about one to ten feet. A transmitter transmits a sequence of electromagnetic pulses in response to a transmit timing signal, and a receiver samples the sequence of electromagnetic pulses with controlled timing in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the sequence of electromagnetic pulses such that the time between transmission of pulses in the sequence and sampling by the receiver sweeps over a range of delays. The receive timing signal sweeps over the range of delays in a sweep cycle such that pulses in the sequence are sampled at the pulse repetition rate, and with different delays in the range of delays to produce a sample signal representing magnitude of a received pulse in equivalent time. Automatic gain control circuitry in the receiver controls the magnitude of the equivalent time sample signal. A signal processor analyzes the sample signal to indicate the time-of-flight of the electromagnetic pulses in the sequence. 7 figs.

  15. The Time-of-Flight trigger at CDF

    SciTech Connect

    Bauer, G.; Mulhearn, M.J.; Paus, Ch.; Schieferdecker, P.; Tether, S.; Lewis, J.D.; Shaw, T.; Acosta, D.; Konigsberg, J.; Madorsky, A.; /Florida U.

    2006-05-01

    The Time-of-Flight (TOF) detector measures the arrival time and deposited energy of charged particles reaching scintillator bars surrounding the central tracking region of the CDF detector. Requiring high ionization in the TOF system provides a unique trigger capability, which has been used for a magnetic monopole search. Other uses, with smaller pulse height thresholds, include a high-multiplicity charged-particle trigger useful for QCD studies and a much improved cosmic ray trigger for calibrating other detector components. Although not designed as input to CDF's global Level 1 trigger, the TOF system has been easily adapted to this role by the addition of 24 cables, new firmware, and four custom TOF trigger boards (TOTRIBs). This article describes the TOF trigger.

  16. Time of flight fast neutron radiography

    NASA Astrophysics Data System (ADS)

    Loveman, R.; Bendahan, J.; Gozani, T.; Stevenson, J.

    1995-05-01

    Neutron radiography with fast or thermal neutrons is a standard technique for non-destructive testing (NDT). Here we report results for fast neutron radiography both as an adjunct to pulsed fast neutron analysis (PFNA) and as a stand-alone method for NDT. PFNA is a new technique for utilizing a collimated pulsed neutron beam to interrogate items and determine their elemental composition. By determining the time of flight for gamma-rays produced by (n,n' gamma X) reactions, a three dimensional image can be produced. Neutron radiography data taken with the same beam provides an important constraint for image reconstruction, and in particular is important in inferring the amount of hydrogen within the interrogated item. As a stand-alone device, the radiography measurement can be used to image items as large as cargo containers as long as their density is not too high. The use of a pulsed beam gives the further advantage of a time of flight measurement on the transmitted neutrons. By gating the radiography signal on the time of flight appropriate to the energy of the primary neutrons, most build-up from scattered neutrons can be eliminated. The pulsed beam also greatly improves the signal to background and extends the range of the neutron radiography. Simulation results will be presented which display the advantage of this constraint in particular for statistically limited data. Experimental results will be presented which show some of the limitations likely in a PFNA system utilizing neutron radiography data. Experimental and simulation results will demonstrate possible uses for this type of radiographic data in identifying contraband substances such as drugs.

  17. Time-of-flight radio location system

    DOEpatents

    McEwan, Thomas E.

    1997-01-01

    A bi-static radar configuration measures the direct time-of-flight of a transmitted RF pulse and is capable of measuring this time-of-flight with a jitter on the order of about one pico-second, or about 0.01 inch of free space distance for an electromagnetic pulse over a range of about one to ten feet. A transmitter transmits a sequence of electromagnetic pulses in response to a transmit timing signal, and a receiver samples the sequence of electromagnetic pulses with controlled timing in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the sequence of electromagnetic pulses such that the time between transmission of pulses in the sequence and sampling by the receiver sweeps over a range of delays. The receive timing signal sweeps over the range of delays in a sweep cycle such that pulses in the sequence are sampled at the pulse repetition rate, and with different delays in the range of delays to produce a sample signal representing magnitude of a received pulse in equivalent time. Automatic gain control circuitry in the receiver controls the magnitude of the equivalent time sample signal. A signal processor analyzes the sample signal to indicate the time-of-flight of the electromagnetic pulses in the sequence. The sample signal in equivalent time is passed through an envelope detection circuit, formed of an absolute value circuit followed by a low pass filter, to convert the sample signal to a unipolar signal to eliminate effects of antenna misorientation.

  18. Time-of-flight radio location system

    DOEpatents

    McEwan, T.E.

    1997-08-26

    A bi-static radar configuration measures the direct time-of-flight of a transmitted RF pulse and is capable of measuring this time-of-flight with a jitter on the order of about one pico-second, or about 0.01 inch of free space distance for an electromagnetic pulse over a range of about one to ten feet. A transmitter transmits a sequence of electromagnetic pulses in response to a transmit timing signal, and a receiver samples the sequence of electromagnetic pulses with controlled timing in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the sequence of electromagnetic pulses such that the time between transmission of pulses in the sequence and sampling by the receiver sweeps over a range of delays. The receive timing signal sweeps over the range of delays in a sweep cycle such that pulses in the sequence are sampled at the pulse repetition rate, and with different delays in the range of delays to produce a sample signal representing magnitude of a received pulse in equivalent time. Automatic gain control circuitry in the receiver controls the magnitude of the equivalent time sample signal. A signal processor analyzes the sample signal to indicate the time-of-flight of the electromagnetic pulses in the sequence. The sample signal in equivalent time is passed through an envelope detection circuit, formed of an absolute value circuit followed by a low pass filter, to convert the sample signal to a unipolar signal to eliminate effects of antenna misorientation. 8 figs.

  19. Time-of-flight Fourier UCN spectrometer

    NASA Astrophysics Data System (ADS)

    Kulin, G. V.; Frank, A. I.; Goryunov, S. V.; Kustov, D. V.; Geltenbort, P.; Jentschel, M.; Lauss, B.; Schmidt-Wellenburg, P.

    2016-05-01

    We describe a new time-of-flight Fourier spectrometer for investigation of UCN diffraction by a moving grating. The device operates in the regime of a discrete set of modulation frequencies. The results of the first experiments show that the spectrometer may be used for obtaining UCN energy spectra in the energy range of 60 - 200 neV with a resolution of about 5 neV. The accuracy of determination of the line position was estimated to be several units of 10-10 eV.

  20. Prototyping of Silicon Strip Detectors for the Inner Tracker of the ALICE Experiment

    NASA Astrophysics Data System (ADS)

    Sokolov, Oleksiy

    2006-04-01

    The ALICE experiment at CERN will study heavy ion collisions at a center-of-mass energy 5.5˜TeV per nucleon. Particle tracking around the interaction region at radii r<45 cm is done by the Inner Tracking System (ITS), consisting of six cylindrical layers of silicon detectors. The outer two layers of the ITS use double-sided silicon strip detectors. This thesis focuses on testing of these detectors and performance studies of the detector module prototypes at the beam test. Silicon strip detector layers will require about 20 thousand HAL25 front-end readout chips and about 3.5 thousand hybrids each containing 6 HAL25 chips. During the assembly procedure, chips are bonded on a patterned TAB aluminium microcables which connect to all the chip input and output pads, and then the chips are assembled on the hybrids. Bonding failures at the chip or hybrid level may either render the component non-functional or deteriorate its the performance such that it can not be used for the module production. After each bonding operation, the component testing is done to reject the non-functional or poorly performing chips and hybrids. The LabView-controlled test station for this operation has been built at Utrecht University and was successfully used for mass production acceptance tests of chips and hybrids at three production labs. The functionality of the chip registers, bonding quality and analogue functionality of the chips and hybrids are addressed in the test. The test routines were optimized to minimize the testing time to make sure that testing is not a bottleneck of the mass production. For testing of complete modules the laser scanning station with 1060 nm diode laser has been assembled at Utrecht University. The testing method relies of the fact that a response of the detector module to a short collimated laser beam pulse resembles a response to a minimum ionizing particle. A small beam spot size (˜7 μm ) allows to deposit the charge in a narrow region and measure the

  1. Miniature Focusing Time-of-Flight Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    Kanik, Isik; Srivastava, Santosh

    2005-01-01

    -particle detector. The output of the detector is fed to a counting circuit to obtain data on the counting rate as a function of time. Inasmuch as time of flight is directly proportional to the ion mass, a plot of the counting rate versus time of flight is equivalent to a mass spectrum (see Figure 2).

  2. Avalanche photodiode based time-of-flight mass spectrometry

    SciTech Connect

    Ogasawara, Keiichi Livi, Stefano A.; Desai, Mihir I.; Ebert, Robert W.; McComas, David J.; Walther, Brandon C.

    2015-08-15

    This study reports on the performance of Avalanche Photodiodes (APDs) as a timing detector for ion Time-of-Flight (TOF) mass spectroscopy. We found that the fast signal carrier speed in a reach-through type APD enables an extremely short timescale response with a mass or energy independent <2 ns rise time for <200 keV ions (1−40 AMU) under proper bias voltage operations. When combined with a microchannel plate to detect start electron signals from an ultra-thin carbon foil, the APD comprises a novel TOF system that successfully operates with a <0.8 ns intrinsic timing resolution even using commercial off-the-shelf constant-fraction discriminators. By replacing conventional total-energy detectors in the TOF-Energy system, APDs offer significant power and mass savings or an anti-coincidence background rejection capability in future space instrumentation.

  3. High-Performance Liquid Chromatography with Diode Array Detector and Electrospray Ionization Ion Trap Time-of-Flight Tandem Mass Spectrometry to Evaluate Ginseng Roots and Rhizomes from Different Regions.

    PubMed

    Wang, Hong-Ping; Zhang, You-Bo; Yang, Xiu-Wei; Yang, Xin-Bao; Xu, Wei; Xu, Feng; Cai, Shao-Qing; Wang, Ying-Ping; Xu, Yong-Hua; Zhang, Lian-Xue

    2016-01-01

    Ginseng, Panax ginseng C. A. Meyer, is an industrial crop in China and Korea. The functional components in ginseng roots and rhizomes are characteristic ginsenosides. This work developed a new high-performance liquid chromatography coupled with electrospray ionization ion trap time-of-flight multistage mass spectrometry (LC-ESI-IT-TOF-MS(n)) method to identify the triterpenoids. Sixty compounds (1-60) including 58 triterpenoids were identified from the ginseng cultivated in China. Substances 1, 2, 7, 15-20, 35, 39, 45-47, 49, 55-57, 59, and 60 were identified for the first time. To evaluate the quality of ginseng cultivated in Northeast China, this paper developed a practical liquid chromatography-diode array detection (LC-DAD) method to simultaneously quantify 14 interesting ginsenosides in ginseng collected from 66 different producing areas for the first time. The results showed the quality of ginseng roots and rhizomes from different sources was different due to growing environment, cultivation technology, and so on. The developed LC-ESI-IT-TOF-MS(n) method can be used to identify many more ginsenosides and the LC-DAD method can be used not only to assess the quality of ginseng, but also to optimize the cultivation conditions for the production of ginsenosides. PMID:27171066

  4. Characterization and determination of isomers in plants using trace matrix solid phase dispersion via ultrahigh performance liquid chromatography coupled with an ultraviolet detector and quadrupole time-of-flight tandem mass spectrometry.

    PubMed

    Xu, Jing-Jing; Cao, Jun; Peng, Li-Qing; Cao, Wan; Zhu, Qiong-Yao; Zhang, Qian-Yun

    2016-03-01

    Here, a novel β-cyclodextrin (β-CD) based trace matrix solid-phase dispersion (MSPD) method was developed to extract isomers from different honeysuckle samples using ultrahigh performance liquid chromatography. The structures of the analytes were characterized and determined via quadrupole time-of-flight tandem mass spectrometry and nuclear magnetic resonance. Under optimum conditions, 25mg of sample was dispersed with 75mg of β-CD, and 0.5mL of methanol was used as the elution solvent. The proposed method produced a good linearity (r(2)>0.99) for the isomers, with limits of detection ranging from 1.62 to 3.33ng/mL. The average recovery values that were obtained from analyzing the spiked samples were calculated to be in the range of 87.04-105.20%. Moreover, the trace MSPD method required less reagents and a shorter extraction time in comparison with the traditional pharmacopoeia method and other reported approaches. The developed method was successfully applied for the determination of three real honeysuckle samples that were collected from different cultivated areas. PMID:26830637

  5. Electrochemical time-of-flight experiment

    SciTech Connect

    Feldman, B.J.; Feldberg, S.W.; Murray, R.W.

    1987-12-17

    A novel experiment to measure electron diffusion rates in polymers is based on the time of flight of electrons across a 2.5-..mu..m film of electroactive material sandwiched between generator and collector electrodes in a lithographically defined interdigitated electrode array. The electrons are generated as a concentration pulse of donor or acceptor states at the generator electrode (by transiently manipulating its potential), cross the polymer film by electron self-exchanges, and are detected as a current at the opposing collector electrode. A digital simulation model is used to account for the electron flight time in terms of the electron diffusion rate in the polymeric film and the array geometry.

  6. Time of flight system on a chip

    NASA Technical Reports Server (NTRS)

    Paschalidis, Nicholas P. (Inventor)

    2006-01-01

    A CMOS time-of-flight TOF system-on-a-chip SoC for precise time interval measurement with low power consumption and high counting rate has been developed. The analog and digital TOF chip may include two Constant Fraction Discriminators CFDs and a Time-to-Digital Converter TDC. The CFDs can interface to start and stop anodes through two preamplifiers and perform signal processing for time walk compensation (110). The TDC digitizes the time difference with reference to an off-chip precise external clock (114). One TOF output is an 11-bit digital word and a valid event trigger output indicating a valid event on the 11-bit output bus (116).

  7. Compact time-of-flight mass spectrometer

    SciTech Connect

    Belov, A.S.; Kubalov, S.A.; Kuzik, V.F.; Yakushev, V.P.

    1986-02-01

    This paper describes a time-of-flight mass spectrometer developed for measuring the parameters of a pulsed hydrogen beam. The duration of an electron-beam current pulse in the ionizer of the mass spectrometer can be varied within 2-20 usec, the pulse electron current is 0.6 mA, and the electron energy is 250 eV. The time resolution of the mass spectrometer is determined by the repetition period of the electron-beam current pulses and is 40 usec. The mass spectrometer has 100% transmission in the direction of motion of molecular-beam particles. The dimension of the mass spectrometer is 7 cm in this direction. The mass resolution is sufficient for determination of the composition of the hydrogen beam.

  8. Miniature Time-of-Flight Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    Potember, Richard S.

    1999-01-01

    Major advances must occur to protect astronauts from prolonged periods in near-zero gravity and high radiation associated with extended space travel. The dangers of living in space must be thoroughly understood and methods developed to reverse those effects that cannot be avoided. Six of the seven research teams established by the National Space Biomedical Research Institute (NSBRI) are studying biomedical factors for prolonged space travel to deliver effective countermeasures. To develop effective countermeasures, each of these teams require identification of and quantitation of complex pharmacological, hormonal, and growth factor compounds (biomarkers) in humans and in experimental animals to develop an in-depth knowledge of the physiological changes associated with space travel. At present, identification of each biomarker requires a separate protocol. Many of these procedures are complicated and the identification of each biomarker requires a separate protocol and associated laboratory equipment. To carry all of this equipment and chemicals on a spacecraft would require a complex clinical laboratory; and it would occupy much of the astronauts time. What is needed is a small, efficient, broadband medical diagnostic instrument to rapidly identify important biomarkers for human space exploration. The Miniature Time-Of- Flight Mass Spectrometer Project in the Technology Development Team is developing a small, high resolution, time-of-flight mass spectrometer (TOFMS) to quantitatively measure biomarkers for human space exploration. Virtues of the JHU/APL TOFMS technologies reside in the promise for a small (less than one cubic ft), lightweight (less than 5 kg), low-power (less than 50 watts), rugged device that can be used continuously with advanced signal processing diagnostics. To date, the JHU/APL program has demonstrated mass capability from under 100 to beyond 10,000 atomic mass units (amu) in a very small, low power prototype for biological analysis. Further

  9. Detection system for high-resolution gamma radiation spectroscopy with neutron time-of-flight filtering

    DOEpatents

    Dioszegi, Istvan; Salwen, Cynthia; Vanier, Peter

    2014-12-30

    A .gamma.-radiation detection system that includes at least one semiconductor detector such as HPGe-Detector, a position-sensitive .alpha.-Detector, a TOF Controller, and a Digitizer/Integrator. The Digitizer/Integrator starts to process the energy signals of a .gamma.-radiation sent from the HPGe-Detector instantly when the HPGe-Detector detects the .gamma.-radiation. Subsequently, it is determined whether a coincidence exists between the .alpha.-particles and .gamma.-radiation signal, based on a determination of the time-of-flight of neutrons obtained from the .alpha.-Detector and the HPGe-Detector. If it is determined that the time-of-flight falls within a predetermined coincidence window, the Digitizer/Integrator is allowed to continue and complete the energy signal processing. If, however, there is no coincidence, the Digitizer/Integrator is instructed to be clear and reset its operation instantly.

  10. The ALICE Electromagnetic Calorimeter

    SciTech Connect

    Awes, Terry C; ALICE, Collaboration

    2010-05-01

    ALICE is the general purpose experiment at the LHC dedicated to the study of heavy-ion collisions. The electromagnetic calorimeter (EMCal) is a late addition to the ALICE suite of detectors with first modules installed in ALICE this year. The EMCal is designed to trigger on high energy gamma-rays and jets, and to enhance the capabilities of ALICE for these measurements. The EMCal is a Pb/scintillator sampling shish-kebab type calorimeter. The EMCal construction, readout, and performance in beam tests at the CERN SPS and PS are described.

  11. The ALICE Electromagnetic Calorimeter

    SciTech Connect

    Awes, Terry C; ALICE, Collaboration

    2010-01-01

    ALICE is the general purpose experiment at the LHC dedicated to the study of heavy-ion collisions. The electromagnetic calorimeter (EMCal) is a late addition to the ALICE suite of detectors with first modules installed in ALICE this year. The EMCal is designed to trigger on high energy gamma-rays and jets, and to enhance the capabilities of ALICE for these measurements. The EMCal is a Pb/scintillator sampling shish-kebab type calorimeter. The EMCal construction, readout, and performance in beam tests at the CERN SPS and PS are described.

  12. Linear electronic field time-of-flight ion mass spectrometers

    DOEpatents

    Funsten, Herbert O.

    2010-08-24

    Time-of-flight mass spectrometer comprising a first drift region and a second drift region enclosed within an evacuation chamber; a means of introducing an analyte of interest into the first drift region; a pulsed ionization source which produces molecular ions from said analyte of interest; a first foil positioned between the first drift region and the second drift region, which dissociates said molecular ions into constituent atomic ions and emits secondary electrons; an electrode which produces secondary electrons upon contact with a constituent atomic ion in second drift region; a stop detector comprising a first ion detection region and a second ion detection region; and a timing means connected to the pulsed ionization source, to the first ion detection region, and to the second ion detection region.

  13. Highly charged ion based time of flight emission microscope

    DOEpatents

    Barnes, Alan V.; Schenkel, Thomas; Hamza, Alex V.; Schneider, Dieter H.; Doyle, Barney

    2001-01-01

    A highly charged ion based time-of-flight emission microscope has been designed, which improves the surface sensitivity of static SIMS measurements because of the higher ionization probability of highly charged ions. Slow, highly charged ions are produced in an electron beam ion trap and are directed to the sample surface. The sputtered secondary ions and electrons pass through a specially designed objective lens to a microchannel plate detector. This new instrument permits high surface sensitivity (10.sup.10 atoms/cm.sup.2), high spatial resolution (100 nm), and chemical structural information due to the high molecular ion yields. The high secondary ion yield permits coincidence counting, which can be used to enhance determination of chemical and topological structure and to correlate specific molecular species.

  14. A Time-of-Flight System for Low Energy Charged Particles

    NASA Astrophysics Data System (ADS)

    Giordano, Micheal; Sadwick, Krystalyn; Fletcher, Kurt; Padalino, Stephen

    2013-10-01

    A time-of-flight system has been developed to measure the energy of charged particles in the keV range. Positively charged ions passing through very thin carbon films mounted on grids generate secondary electrons. These electrons are accelerated by a -2000 V grid bias towards a grounded channeltron electron multiplier (CEM) which amplifies the signal. Two CEM detector assemblies are mounted 23.1 cm apart along the path of the ions. An ion generates a start signal by passing through the first CEM and a stop signal by passing through the second. The start and stop signals generate a time-of-flight spectrum via conventional electronics. Higher energy alpha particles from radioactive sources have been used to test the system. This time-of-flight system will be deployed to measure the energies of 15 to 30 keV ions produced by a duoplasmatron ion source that is used to characterize ICF detectors.

  15. Time-of-Flight Microwave Camera

    NASA Astrophysics Data System (ADS)

    Charvat, Gregory; Temme, Andrew; Feigin, Micha; Raskar, Ramesh

    2015-10-01

    Microwaves can penetrate many obstructions that are opaque at visible wavelengths, however microwave imaging is challenging due to resolution limits associated with relatively small apertures and unrecoverable “stealth” regions due to the specularity of most objects at microwave frequencies. We demonstrate a multispectral time-of-flight microwave imaging system which overcomes these challenges with a large passive aperture to improve lateral resolution, multiple illumination points with a data fusion method to reduce stealth regions, and a frequency modulated continuous wave (FMCW) receiver to achieve depth resolution. The camera captures images with a resolution of 1.5 degrees, multispectral images across the X frequency band (8 GHz-12 GHz), and a time resolution of 200 ps (6 cm optical path in free space). Images are taken of objects in free space as well as behind drywall and plywood. This architecture allows “camera-like” behavior from a microwave imaging system and is practical for imaging everyday objects in the microwave spectrum.

  16. Time-of-Flight Microwave Camera

    PubMed Central

    Charvat, Gregory; Temme, Andrew; Feigin, Micha; Raskar, Ramesh

    2015-01-01

    Microwaves can penetrate many obstructions that are opaque at visible wavelengths, however microwave imaging is challenging due to resolution limits associated with relatively small apertures and unrecoverable “stealth” regions due to the specularity of most objects at microwave frequencies. We demonstrate a multispectral time-of-flight microwave imaging system which overcomes these challenges with a large passive aperture to improve lateral resolution, multiple illumination points with a data fusion method to reduce stealth regions, and a frequency modulated continuous wave (FMCW) receiver to achieve depth resolution. The camera captures images with a resolution of 1.5 degrees, multispectral images across the X frequency band (8 GHz–12 GHz), and a time resolution of 200 ps (6 cm optical path in free space). Images are taken of objects in free space as well as behind drywall and plywood. This architecture allows “camera-like” behavior from a microwave imaging system and is practical for imaging everyday objects in the microwave spectrum. PMID:26434598

  17. Advances in time-of-flight PET.

    PubMed

    Surti, Suleman; Karp, Joel S

    2016-01-01

    This paper provides a review and an update on time-of-flight PET imaging with a focus on PET instrumentation, ranging from hardware design to software algorithms. We first present a short introduction to PET, followed by a description of TOF PET imaging and its history from the early days. Next, we introduce the current state-of-art in TOF PET technology and briefly summarize the benefits of TOF PET imaging. This is followed by a discussion of the various technological advancements in hardware (scintillators, photo-sensors, electronics) and software (image reconstruction) that have led to the current widespread use of TOF PET technology, and future developments that have the potential for further improvements in the TOF imaging performance. We conclude with a discussion of some new research areas that have opened up in PET imaging as a result of having good system timing resolution, ranging from new algorithms for attenuation correction, through efficient system calibration techniques, to potential for new PET system designs. PMID:26778577

  18. Time-of-Flight Microwave Camera.

    PubMed

    Charvat, Gregory; Temme, Andrew; Feigin, Micha; Raskar, Ramesh

    2015-01-01

    Microwaves can penetrate many obstructions that are opaque at visible wavelengths, however microwave imaging is challenging due to resolution limits associated with relatively small apertures and unrecoverable "stealth" regions due to the specularity of most objects at microwave frequencies. We demonstrate a multispectral time-of-flight microwave imaging system which overcomes these challenges with a large passive aperture to improve lateral resolution, multiple illumination points with a data fusion method to reduce stealth regions, and a frequency modulated continuous wave (FMCW) receiver to achieve depth resolution. The camera captures images with a resolution of 1.5 degrees, multispectral images across the X frequency band (8 GHz-12 GHz), and a time resolution of 200 ps (6 cm optical path in free space). Images are taken of objects in free space as well as behind drywall and plywood. This architecture allows "camera-like" behavior from a microwave imaging system and is practical for imaging everyday objects in the microwave spectrum. PMID:26434598

  19. L0 Trigger for the EMCal Detector of the ALICE Experiment

    SciTech Connect

    Kral, Jiri; Awes, Terry C; Muller, Hans; Rak, Jan; Schambach, Joachim

    2012-01-01

    The ALICE experiment at the CERN Large Hadron Collider (LHC) accelerator was designed to study ultra-relativistic heavy-ion collisions. The ALICE Electromagnetic Calorimeter (EMCal) was built to provide measurement of photons, electrons, and jets, and trigger selection of hard-QCD events containing them. The EMCal single-shower L0 trigger, which triggers on large energy deposit within a 4 x 4 tower sliding window, became operational in 2010. The implementation of the real-time FPGA based algorithm optimized to provide a fast L0 decision is presented.

  20. Developments and tests of double-sided silicon strip detectors and read-out electronics for the Internal Tracking System of ALICE at LHC

    NASA Astrophysics Data System (ADS)

    Coffin, J. P.; Alice Collaboration

    1999-12-01

    The internal-tracking-system (ITS) of the ALICE detector at LHC, consists of six concentrical barrels of silicon detectors. The outmost two layers are made of double-sided strip detectors (SSD). In the framework of a R&D, the characteristics and performances of these devices, manufactured by two different companies, associated with their designed read-out electronics, have been studied off- and in-beam at the SPS (CERN). The results are presented and discussed.

  1. Proposed STAR Time of Flight Readout Electronics and DAQ

    NASA Astrophysics Data System (ADS)

    Schambach, Joachim

    2006-04-01

    A novel Time-of-Flight (TOF) subsystem is under design for the STAR detector at RHIC. A total of 3840 Multi-gap Resistive Plate Chambers (MRPC) of 6 pads each are distributed over 120 trays. The total number of channels is 23040. Each TOF tray consists of 192 detector channels and three different types of electronic circuit cards, called "TINO", "TDIG", and "TCPU", listed in order of the data flow. Every 30 trays send their data to a "THUB" card that interfaces to the STAR trigger and transmits the data over a fiber to a fiber receiver which is part of STAR DAQ. The TINO contains the analog front end electronics based on a custom IC called NINO. The output of TINO is passed to the TDIG, where the data are digitized (using the CERN HPTDC ASIC). The TCPU formats and buffers the digital detector information. This formatted data is passed to THUB, which transmits it over an optical fiber to a data receiver in the STAR DAQ room. The architecture of this readout chain and DAQ will be described, and first results from prototypes of the component boards will be discussed.

  2. (Multi-)strange hadron and light (anti-)nuclei production with ALICE at the LHC

    NASA Astrophysics Data System (ADS)

    Lea, Ramona

    2016-01-01

    Thanks to its excellent tracking performance and particle identification capabilities, the ALICE detector allows for the identification of light (anti-)(hyper)nuclei and for the measurement of (multi-)strange particles over a wide range of transverse momentum. Deuterons, 3He and 4He and their corresponding anti-nuclei are identified via their specific energy loss in the Time Projection Chamber and the velocity measurement provided by the Time-Of-Flight detector. Strange and multi-strange baryons and mesons as well as (anti-)hypertritons are reconstructed via their topological decays. Detailed measurements of (multi-)strange hadron production in pp, p-Pb and Pb-Pb collision and of light (anti-)nuclei and (anti-)hypertritons in Pb-Pb collisions with ALICE at the LHC are presented. The experimental results will be compared with the predictions of both statistical hadronization and coalescence models.

  3. Combined distance-of-flight and time-of-flight mass spectrometer

    DOEpatents

    Enke, Christie G; Ray, Steven J; Graham, Alexander W; Hieftje, Gary M; Barinaga, Charles J; Koppenaal, David W

    2014-02-11

    A combined distance-of-flight mass spectrometry (DOFMS) and time-of-flight mass spectrometry (TOFMS) instrument includes an ion source configured to produce ions having varying mass-to-charge ratios, a first detector configured to determine when each of the ions travels a predetermined distance, a second detector configured to determine how far each of the ions travels in a predetermined time, and a detector extraction region operable to direct portions of the ions either to the first detector or to the second detector.

  4. Measurement of reference cross sections in pp and Pb-Pb collisions at the LHC in van der Meer scans with the ALICE detector

    NASA Astrophysics Data System (ADS)

    Gagliardi, M.; Alice Collaboration

    2012-03-01

    Reference cross sections have been measured with the ALICE detector in both pp and Pb-Pb collisions, in dedicated luminosity calibration experiments (van der Meer scans) at the LHC. The results and their uncertainties are discussed, together with a few selected applications.

  5. Study of muon bundles from extensive air showers with the ALICE detector at CERN LHC

    NASA Astrophysics Data System (ADS)

    Shtejer, K.

    2016-05-01

    ALICE is one of four large experiments at the CERN Large Hadron Collider, specially designed to study particle production in ultra-relativistic heavy-ion collisions. Located 52 meters underground with 28 meters of overburden rock, it has also been used to detect muons produced by cosmic-ray interactions in the upper atmosphere. The large size and excellent tracking capability of the ALICE Time Projection Chamber are exploited to study the muonic component of extensive air showers. We present the multiplicity distribution of these atmospheric muons and its comparison with Monte Carlo simulations. The latest version of the QGSJET hadronic interaction model was used to simulate the development of the resulting air showers. High multiplicity events containing more than 100 reconstructed muons were also studied. Similar events have been studied in previous underground experiments such as ALEPH and DELPHI at LEP without satisfactory explanations for the frequency of the highest multiplicity events. We demonstrate that the high muon-multiplicity events observed in ALICE stem from primary cosmic rays with energies above 1016 eV and that the frequency of these events can be successfully described by assuming a heavy mass composition of primary cosmic rays in this energy range.

  6. 14 CFR 398.7 - Timing of flights.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Timing of flights. 398.7 Section 398.7 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) POLICY STATEMENTS GUIDELINES FOR INDIVIDUAL DETERMINATIONS OF BASIC ESSENTIAL AIR SERVICE § 398.7 Timing of flights. To qualify as essential air...

  7. Electronics for a Picosecond Time-of-flight Measurement

    SciTech Connect

    Brandt, Andrew Gerhart; Rijssenbeek, Michael

    2014-11-03

    TITLE: Electronics for a Picosecond Time-of-flight Measurement ABSTRACT: Time-of-flight (TOF) detectors have historically been used as part of the particle identification capability of multi-purpose particle physics detectors. An accurate time measurement, combined with a momentum measurement based on the curvature of the track in a magnetic field, is often sufficient to determine the particle's mass, and thus its identity. Such detectors typically have measured the particle flight time extremely precisely, with an uncertainty of one hundred trillionths of a second (also referred to as 100 picoseconds). To put this in perspective it would be like counting all the people on the Earth and getting it right within 1 person! Another use of TOFs is to measure the vertex of the event, which is the location along the beam line where the incoming particles (typically protons) collide. This vertex positon is a well measured quantity for events where the protons collide “head on” as the outgoing particles produced when you blast the proton apart can be used to trace back to a vertex point from which they originated. More frequently the protons just strike a glancing blow and remain intact—in this case they are nearly parallel to the beam and you cannot tell their vertex without this ability to precisely measure the time of flight of the protons. Occasionally both happen in the same event, that is, a central system and two protons are produced. But are they from the same collision, or just a boring background where more than one collision in the same bunch crossing conspire to fake the signal of interest? That’s where the timing of the protons comes into play. The main idea is to measure the time it takes for the two protons to reach TOF detectors positioned equidistant from the center of the main detector. If the vertex is displaced to one side than that detector will measure a shorter time while the other side detector will measure a correspondingly longer time

  8. Performance of the Tachyon Time-of-Flight PET Camera

    PubMed Central

    Peng, Q.; Choong, W.-S.; Vu, C.; Huber, J. S.; Janecek, M.; Wilson, D.; Huesman, R. H.; Qi, Jinyi; Zhou, Jian; Moses, W. W.

    2015-01-01

    We have constructed and characterized a time-of-flight Positron Emission Tomography (TOF PET) camera called the Tachyon. The Tachyon is a single-ring Lutetium Oxyorthosilicate (LSO) based camera designed to obtain significantly better timing resolution than the ~ 550 ps found in present commercial TOF cameras, in order to quantify the benefit of improved TOF resolution for clinically relevant tasks. The Tachyon’s detector module is optimized for timing by coupling the 6.15 × 25 mm2 side of 6.15 × 6.15 × 25 mm3 LSO scintillator crystals onto a 1-inch diameter Hamamatsu R-9800 PMT with a super-bialkali photocathode. We characterized the camera according to the NEMA NU 2-2012 standard, measuring the energy resolution, timing resolution, spatial resolution, noise equivalent count rates and sensitivity. The Tachyon achieved a coincidence timing resolution of 314 ps +/− ps FWHM over all crystal-crystal combinations. Experiments were performed with the NEMA body phantom to assess the imaging performance improvement over non-TOF PET. The results show that at a matched contrast, incorporating 314 ps TOF reduces the standard deviation of the contrast by a factor of about 2.3. PMID:26594057

  9. Positron Emission Tomography (PET): Towards Time of Flight

    SciTech Connect

    Karp, Joel

    2004-09-29

    PET is a powerful imaging tool that is being used to study cancer, using a variety of tracers to measure physiological processes including glucose metabolism, cell proliferation, and hypoxia in tumor cells. As the utilization of PET has grown in the last several years, it has become clear that improved lesion detection and quantification are critical goals for cancer studies. Although physical performance of the current generation of PET scanners has improved recently, there are limitations especially for heavy patients where attenuation and scatter effects are increased. We are investigating new scintillation detectors, scanner designs, and image processing algorithms in order to overcome these limitations and improve performance. In particular, we are studying scanner designs that would incorporate scintillators with improved energy and timing resolution. Improved energy resolution helps to reduce scattered radiation, and improved timing resolution makes it feasible to incorporate the time-of-flight information between the two coincident gamma rays into the image reconstruction algorithm, a technique that improves signal-to-noise. Results of recent experiments and computer simulations will be shown to demonstrate these potential improvements.

  10. Performance of the Tachyon Time-of-Flight PET Camera

    DOE PAGESBeta

    Peng, Q.; Choong, W. -S.; Vu, C.; Huber, J. S.; Janecek, M.; Wilson, D.; Huesman, R. H.; Qi, Jinyi; Zhou, Jian; Moses, W. W.

    2015-01-23

    We have constructed and characterized a time-of-flight Positron Emission Tomography (TOF PET) camera called the Tachyon. The Tachyon is a single-ring Lutetium Oxyorthosilicate (LSO) based camera designed to obtain significantly better timing resolution than the ~ 550 ps found in present commercial TOF cameras, in order to quantify the benefit of improved TOF resolution for clinically relevant tasks. The Tachyon's detector module is optimized for timing by coupling the 6.15 ×25 mm2 side of 6.15 ×6.15 ×25 mm3 LSO scintillator crystals onto a 1-inch diameter Hamamatsu R-9800 PMT with a super-bialkali photocathode. We characterized the camera according to the NEMAmore » NU 2-2012 standard, measuring the energy resolution, timing resolution, spatial resolution, noise equivalent count rates and sensitivity. The Tachyon achieved a coincidence timing resolution of 314 ps +/- 20 ps FWHM over all crystal-crystal combinations. Experiments were performed with the NEMA body phantom to assess the imaging performance improvement over non-TOF PET. We find that the results show that at a matched contrast, incorporating 314 ps TOF reduces the standard deviation of the contrast by a factor of about 2.3.« less

  11. Performance of the Tachyon Time-of-Flight PET Camera

    SciTech Connect

    Peng, Q.; Choong, W. -S.; Vu, C.; Huber, J. S.; Janecek, M.; Wilson, D.; Huesman, R. H.; Qi, Jinyi; Zhou, Jian; Moses, W. W.

    2015-01-23

    We have constructed and characterized a time-of-flight Positron Emission Tomography (TOF PET) camera called the Tachyon. The Tachyon is a single-ring Lutetium Oxyorthosilicate (LSO) based camera designed to obtain significantly better timing resolution than the ~ 550 ps found in present commercial TOF cameras, in order to quantify the benefit of improved TOF resolution for clinically relevant tasks. The Tachyon's detector module is optimized for timing by coupling the 6.15 ×25 mm2 side of 6.15 ×6.15 ×25 mm3 LSO scintillator crystals onto a 1-inch diameter Hamamatsu R-9800 PMT with a super-bialkali photocathode. We characterized the camera according to the NEMA NU 2-2012 standard, measuring the energy resolution, timing resolution, spatial resolution, noise equivalent count rates and sensitivity. The Tachyon achieved a coincidence timing resolution of 314 ps +/- 20 ps FWHM over all crystal-crystal combinations. Experiments were performed with the NEMA body phantom to assess the imaging performance improvement over non-TOF PET. We find that the results show that at a matched contrast, incorporating 314 ps TOF reduces the standard deviation of the contrast by a factor of about 2.3.

  12. Particle identification in ALICE: a Bayesian approach

    NASA Astrophysics Data System (ADS)

    Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, S.; Ahn, S. U.; Aiola, S.; Akindinov, A.; Alam, S. N.; Albuquerque, D. S. D.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Almaraz, J. R. M.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Andrei, C.; Andronic, A.; Anguelov, V.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Arnaldi, R.; Arnold, O. W.; Arsene, I. C.; Arslandok, M.; Audurier, B.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Balasubramanian, S.; Baldisseri, A.; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Barth, K.; Bartke, J.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bello Martinez, H.; Bellwied, R.; Belmont, R.; Belmont-Moreno, E.; Belyaev, V.; Benacek, P.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biro, G.; Biswas, R.; Biswas, S.; Bjelogrlic, S.; Blair, J. T.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Bossú, F.; Botta, E.; Bourjau, C.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Butt, J. B.; Buxton, J. T.; Cabala, J.; Caffarri, D.; Cai, X.; Caines, H.; Calero Diaz, L.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Carena, F.; Carena, W.; Carnesecchi, F.; Castillo Castellanos, J.; Castro, A. J.; Casula, E. A. R.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Cerkala, J.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chauvin, A.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Cho, S.; Chochula, P.; Choi, K.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortés Maldonado, I.; Cortese, P.; Cosentino, M. R.; Costa, F.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danisch, M. C.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; De, S.; De Caro, A.; de Cataldo, G.; de Conti, C.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; Deisting, A.; Deloff, A.; Dénes, E.; Deplano, C.; Dhankher, P.; Di Bari, D.; Di Mauro, A.; Di Nezza, P.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Drozhzhova, T.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Endress, E.; Engel, H.; Epple, E.; Erazmus, B.; Erdemir, I.; Erhardt, F.; Espagnon, B.; Estienne, M.; Esumi, S.; Eum, J.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabbietti, L.; Fabris, D.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Feuillard, V. J. G.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Fleck, M. G.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fronze, G. G.; Fuchs, U.; Furget, C.; Furs, A.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Gasik, P.; Gauger, E. F.; Germain, M.; Gheata, A.; Gheata, M.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Gladysz-Dziadus, E.; Glässel, P.; Goméz Coral, D. M.; Gomez Ramirez, A.; Gonzalez, A. S.; Gonzalez, V.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Grabski, V.; Grachov, O. A.; Graczykowski, L. K.; Graham, K. L.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Gronefeld, J. M.; Grosse-Oetringhaus, J. F.; Grosso, R.; Guber, F.

    2016-05-01

    We present a Bayesian approach to particle identification (PID) within the ALICE experiment. The aim is to more effectively combine the particle identification capabilities of its various detectors. After a brief explanation of the adopted methodology and formalism, the performance of the Bayesian PID approach for charged pions, kaons and protons in the central barrel of ALICE is studied. PID is performed via measurements of specific energy loss ( d E/d x) and time of flight. PID efficiencies and misidentification probabilities are extracted and compared with Monte Carlo simulations using high-purity samples of identified particles in the decay channels K0S → π-π+, φ→ K-K+, and Λ→ p π- in p-Pb collisions at √{s_{NN}}=5.02 TeV. In order to thoroughly assess the validity of the Bayesian approach, this methodology was used to obtain corrected pT spectra of pions, kaons, protons, and D0 mesons in pp collisions at √{s}=7 TeV. In all cases, the results using Bayesian PID were found to be consistent with previous measurements performed by ALICE using a standard PID approach. For the measurement of D0 → K-π+, it was found that a Bayesian PID approach gave a higher signal-to-background ratio and a similar or larger statistical significance when compared with standard PID selections, despite a reduced identification efficiency. Finally, we present an exploratory study of the measurement of Λc+ → p K-π+ in pp collisions at √{s}=7 TeV, using the Bayesian approach for the identification of its decay products.

  13. Development of a three-electrode-lens drift tube for time-of-flight mass spectrometry.

    PubMed

    Sakamoto, H; Takakuwa, Y; Hori, T; Enta, Y; Kato, H; Miyamoto, N

    1998-05-01

    A three-electrode-lens drift tube for time-of-flight mass spectrometry (TOF-MS) has been developed for utilizing a detector to observe photon-stimulated desorption (PSD). In spite of a small detection area, the detector has a high detection efficiency and durability to reactive gas atmosphere at high pressure. The TOF-MS performance of the drift tube was examined for PSD using single-bunch-mode synchrotron radiation on a dichlorosilane (SiH(2)Cl(2))-saturated Si(001) surface. The measured acceleration and focusing-voltage dependences of the time of flight, intensity and full width at half-maximum for the peak of H(+) and Cl(+) PSD ions are discussed in terms of the numerical calculations of ion trajectories and focusing characteristic of the drift tube. PMID:15263595

  14. Digitizing data acquisition and time-of-flight pulse processing for ToF-ERDA

    NASA Astrophysics Data System (ADS)

    Julin, Jaakko; Sajavaara, Timo

    2016-01-01

    A versatile system to capture and analyze signals from multi channel plate (MCP) based time-of-flight detectors and ionization based energy detectors such as silicon diodes and gas ionization chambers (GIC) is introduced. The system is based on commercial digitizers and custom software. It forms a part of a ToF-ERDA spectrometer, which has to be able to detect recoil atoms of many different species and energies. Compared to the currently used analogue electronics the digitizing system provides comparable time-of-flight resolution and improved hydrogen detection efficiency, while allowing the operation of the spectrometer be studied and optimized after the measurement. The hardware, data acquisition software and digital pulse processing algorithms to suit this application are described in detail.

  15. Effect of different drying methods on the quality of Angelicae Sinensis Radix evaluated through simultaneously determining four types of major bioactive components by high performance liquid chromatography photodiode array detector and ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometry.

    PubMed

    Bai, Ying-Jia; Kong, Ming; Xu, Jin-Di; Zhang, Xiao-Lin; Zhou, Shan-Shan; Wang, Xiao-Ning; Liu, Li-Fang; Li, Song-Lin

    2014-06-01

    In the present study, the effect of drying methods on the quality of Angelicae Sinensis Radix (DG), was evaluated by newly developed high performance liquid chromatography photodiode array detector (HPLC-DAD) and ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS/MS). Ten major bioactive components including two phenolic acids, two hydroxyl phthalides, four alkyl phthalides and two phthalide dimers were selected as evaluation chemical markers and the newly-established method was qualitatively and quantitatively validated. DG slices and whole roots dried in shade, sun light, hot air, vacuum, microwave, far infrared ray and combination of microwave and far infrared ray as well as the fresh DG samples were determined by the established methods. DG slices dried in hot air kept the similar chemical composition to that of fresh DG, while DG whole roots dried in vacuum retained highest contents of the major components. Coniferyl ferulate and ligustilide degraded significantly in DG slices dried by microwave, far infrared ray and their combination. The influence of such chemical changes induced by different drying methods on the bioactivities of DG warrants further investigation, so that the optimal drying method can be obtained for the standardization of DG herb. PMID:24561333

  16. Multi-anode detection in electrospray ionization time-of-flight mass spectrometry.

    PubMed

    Barbacci, D C; Russell, D H; Schultz, J A; Holocek, J; Ulrich, S; Burton, W; Van Stipdonk, M

    1998-12-01

    An electrospray ionization ion source coupled to a time-of-flight mass analyzer incorporating a multi-anode time-to-digital converter is described. High-speed data acquisition (kHz mass spectral acquisition) rates are achieved. The four-anode detector produces a significant increase in detection/counting efficiency over that for a single-anode detector. In this work a 2.5 times increase in detection efficiency is demonstrated. The multi-anode detector is also used as a diagnostic tool to optimize transmission of the ion optics. PMID:9835077

  17. Parameters’ Covariance in Neutron Time of Flight Analysis – Explicit Formulae

    SciTech Connect

    Odyniec, M.; Blair, J.

    2014-12-01

    We present here a method that estimates the parameters’ variance in a parametric model for neutron time of flight (NToF). The analytical formulae for parameter variances, obtained independently of calculation of parameter values from measured data, express the variances in terms of the choice, settings, and placement of the detector and the oscilloscope. Consequently, the method can serve as a tool in planning a measurement setup.

  18. Neutron xyz - polarization analysis at a time-of-flight instrument

    SciTech Connect

    Ehlers, Georg; Stewart, John Ross; Andersen, Ken

    2015-01-01

    When implementing a dedicated polarization analysis setup at a neutron time-of-flight instrument with a large area detector, one faces enormous challenges. Nevertheless, significant progress has been made towards this goal over the last few years. This paper addresses systematic limitations of the traditional method that is used to make these measurements, and a possible strategy to overcome these limitations. This will be important, for diffraction as well as inelastic experiments, where the scattering occurs mostly out-of-plane.

  19. Analytical Properties of Time-of-Flight PET Data

    PubMed Central

    Cho, Sanghee; Ahn, Sangtae; Li, Quanzheng; Leahy, Richard M.

    2015-01-01

    We investigate the analytical properties of time-of-flight (TOF) positron emission tomography (PET) sinograms, where the data are modeled as line integrals weighted by a spatially invariant TOF kernel. First, we investigate the Fourier transform properties of 2D TOF data and extend the “bow-tie” property of the 2D Radon transform to the time of flight case. Second, we describe a new exact Fourier rebinning method, TOF-FOREX, based on the Fourier transform in the time-of-flight variable. We then combine TOF-FOREX rebinning with a direct extension of the projection slice theorem to TOF data, to perform fast 3D TOF PET image reconstruction. Finally, we illustrate these properties using simulated data. PMID:18460746

  20. Analytical properties of time-of-flight PET data.

    PubMed

    Cho, Sanghee; Ahn, Sangtae; Li, Quanzheng; Leahy, Richard M

    2008-06-01

    We investigate the analytical properties of time-of-flight (TOF) positron emission tomography (PET) sinograms, where the data are modeled as line integrals weighted by a spatially invariant TOF kernel. First, we investigate the Fourier transform properties of 2D TOF data and extend the 'bow-tie' property of the 2D Radon transform to the time-of-flight case. Second, we describe a new exact Fourier rebinning method, TOF-FOREX, based on the Fourier transform in the time-of-flight variable. We then combine TOF-FOREX rebinning with a direct extension of the projection slice theorem to TOF data, to perform fast 3D TOF PET image reconstruction. Finally, we illustrate these properties using simulated data. PMID:18460746

  1. Analytical properties of time-of-flight PET data

    NASA Astrophysics Data System (ADS)

    Cho, Sanghee; Ahn, Sangtae; Li, Quanzheng; Leahy, Richard M.

    2008-06-01

    We investigate the analytical properties of time-of-flight (TOF) positron emission tomography (PET) sinograms, where the data are modeled as line integrals weighted by a spatially invariant TOF kernel. First, we investigate the Fourier transform properties of 2D TOF data and extend the 'bow-tie' property of the 2D Radon transform to the time-of-flight case. Second, we describe a new exact Fourier rebinning method, TOF-FOREX, based on the Fourier transform in the time-of-flight variable. We then combine TOF-FOREX rebinning with a direct extension of the projection slice theorem to TOF data, to perform fast 3D TOF PET image reconstruction. Finally, we illustrate these properties using simulated data.

  2. Recent developments in time-of-flight PET.

    PubMed

    Vandenberghe, S; Mikhaylova, E; D'Hoe, E; Mollet, P; Karp, J S

    2016-12-01

    While the first time-of-flight (TOF)-positron emission tomography (PET) systems were already built in the early 1980s, limited clinical studies were acquired on these scanners. PET was still a research tool, and the available TOF-PET systems were experimental. Due to a combination of low stopping power and limited spatial resolution (caused by limited light output of the scintillators), these systems could not compete with bismuth germanate (BGO)-based PET scanners. Developments on TOF system were limited for about a decade but started again around 2000. The combination of fast photomultipliers, scintillators with high density, modern electronics, and faster computing power for image reconstruction have made it possible to introduce this principle in clinical TOF-PET systems. This paper reviews recent developments in system design, image reconstruction, corrections, and the potential in new applications for TOF-PET. After explaining the basic principles of time-of-flight, the difficulties in detector technology and electronics to obtain a good and stable timing resolution are shortly explained. The available clinical systems and prototypes under development are described in detail. The development of this type of PET scanner also requires modified image reconstruction with accurate modeling and correction methods. The additional dimension introduced by the time difference motivates a shift from sinogram- to listmode-based reconstruction. This reconstruction is however rather slow and therefore rebinning techniques specific for TOF data have been proposed. The main motivation for TOF-PET remains the large potential for image quality improvement and more accurate quantification for a given number of counts. The gain is related to the ratio of object size and spatial extent of the TOF kernel and is therefore particularly relevant for heavy patients, where image quality degrades significantly due to increased attenuation (low counts) and high scatter fractions. The

  3. Time-of-Flight Experiments of Vortex Rings Propagating from Turbulent Region of Superfluid 4He at High Temperature

    NASA Astrophysics Data System (ADS)

    Nago, Y.; Ogawa, T.; Obara, K.; Yano, H.; Ishikawa, O.; Hata, T.

    2011-02-01

    We report the time-of-flight of quantized vortex rings generated by a vibrating wire in superfluid 4He which contains normal fluid component. A cover box of vibrating wires and slow cooling of superfluid reduce the number of vortices attached to wire surfaces, enabling us to study vortex rings propagating from a turbulent region. Using two vibrating wires as a generator and a detector of vortices, the time-of-flight of vortices propagating a distance of 0.88 mm was measured at 1.25 K. We find that the time-of-flights distribute from 0.06 s to 27.4 s, much larger than the lifetimes of circular vortex rings limited in the size of a generator amplitude. These results imply that large vortex rings with non-circular shape or vortex tangles are created by the generator, propagating slowly and colliding with the detector before complete disappearance.

  4. Electrochemical time of flight method for determination of diffusion coefficients of glucose in solutions and gels.

    PubMed

    Varga, Agnes; Gyetvai, Gergely; Nagy, Lívia; Nagy, Géza

    2009-08-01

    The diffusion coefficient of glucose in different media is an important parameter in life sciences, as well as in biotechnology and microbiology. In this work a simple, fast method is proposed that is based on the electrochemical time of flight principle. In most of the earlier time of flight experiments performed, a constant flight distance was applied. In the present work a scanning electrochemical microscope (SECM) was applied as a measuring tool. With use of the SECM, the flying distance could be changed with high precision, making measurements with several flight distances more accurate and reliable values could be obtained for solutions as well as for gels. The conventional voltammetric methods are not applicable for glucose detection. In our work electrocatalytic copper oxide coated copper microelectrodes and micro-sized amperometric enzyme sensors were used as detectors, while microdroplet-ejecting pneumatically driven micropipettes were used as a source. PMID:19517100

  5. Time-of-flight x-ray photoconductivity of HgI2

    NASA Astrophysics Data System (ADS)

    Kurtz, S. R.; Hughes, R. C.; Ortale, C.; Schnepple, W. F.

    1987-11-01

    Time-of-flight photoconductivity measurements were performed on HgI2 using a penetrating, pulsed x-ray source, simulating the operation of photoconductive x-ray detectors. By examining a variety of HgI2 samples, a wide range of electron and hole mobilities were observed, but in all cases hole transport was highly localized, limiting the collection of the photocarriers in HgI2 detectors. The intrinsic photocarrier generation and recombination processes differed from classical Onsager and Langevin mechanisms observed in low-mobility photoconductors.

  6. A composition analyzer for microparticles using a spark ion source. [using time of flight spectrometers

    NASA Technical Reports Server (NTRS)

    Auer, S. O.; Berg, O. E.

    1975-01-01

    Iron microparticles were fired onto a capacitor-type microparticle detector which responded to an impact with a spark discharge. Ion currents were extracted from the spark and analyzed in a time-of-flight mass spectrometer. The mass spectra showed the element of both detector and particle materials. The total extracted ion currents was typically 10A within a period of 100ns, indicating very efficient vaporization of the particle and ionization of the vapor. Potential applications include research on cosmic dust, atmospheric aerosols and cloud droplets, particles ejected by rocket or jet engines, by machining processes, or by nuclear bomb explosions.

  7. Particle identification using time-of-flight technology for the ALICE experiment

    SciTech Connect

    Schmidt, H.R.

    1995-07-15

    The large multiplicities expected for LHC Pb+Pb collisions require new development in particle identification techniques. Presently, Pestov Spark Counters, low pressure Parallel Plate Chambers and scintillators with photo multiplier readout are under consideration.

  8. Compensation of Motion Artifacts for Time-of-Flight Cameras

    NASA Astrophysics Data System (ADS)

    Lindner, Marvin; Kolb, Andreas

    During the last years, Time-of-Flight sensors achieved a significant impact onto research fields in computer vision. For dynamic scenes however, most sensor’s working principles lead to significant artifacts in respect to sensor or object motion - artifacts that commonly affect distance reliability and thus affect downstream processing tasks in a negative way.

  9. Rocket-borne time-of-flight mass spectrometry

    NASA Technical Reports Server (NTRS)

    Reiter, R. F.

    1976-01-01

    Theoretical and numerical analyses are made of planar, cylindrical and spherical-electrode two-field time-of-flight mass spectrometers in order to optimize their operating conditions. A method is introduced which can improve the resolving power of these instruments by a factor of 7.5. Potential barrier gating in time-of-flight mass spectrometers is also analyzed. Experimental studies of a miniature cylindrical-electrode and a hemispherical-electrode time-of-flight mass spectrometer are presented. Their sensitivity and ability to operate at D-region pressures with an open source make them ideal instruments for D-region ion composition measurements. A sounding rocket experiment package carrying a cylindrical electrode time-of-flight mass spectrometer was launched. The data indicate that essentially 100% of the positive electric charge on positive ions is carried by ions with mass-to-charge ratios greater than 500 below an altitude of 92 km. These heavy charge carriers were present at altitudes up to about 100 km.

  10. Time-of-flight imaging of invisibility cloaks.

    PubMed

    Halimeh, Jad C; Wegener, Martin

    2012-01-01

    As invisibility cloaking has recently become experimental reality, it is interesting to explore ways to reveal remaining imperfections. In essence, the idea of most invisibility cloaks is to recover the optical path lengths without an object (to be made invisible) by a suitable arrangement around that object. Optical path length is proportional to the time of flight of a light ray or to the optical phase accumulated by a light wave. Thus, time-of-flight images provide a direct and intuitive tool for probing imperfections. Indeed, recent phase-sensitive experiments on the carpet cloak have already made early steps in this direction. In the macroscopic world, time-of-flight images could be measured directly by light detection and ranging (LIDAR). Here, we show calculated time-of-flight images of the conformal Gaussian carpet cloak, the conformal grating cloak, the cylindrical free-space cloak, and of the invisible sphere. All results are obtained by using a ray-velocity equation of motion derived from Fermat's principle. PMID:22274329

  11. Highly segmented, high resolution time-of-flight system

    SciTech Connect

    Nayak, T.K.; Nagamiya, S.; Vossnack, O.; Wu, Y.D.; Zajc, W.A.; Miake, Y.; Ueno, S.; Kitayama, H.; Nagasaka, Y.; Tomizawa, K.; Arai, I.; Yagi, K

    1991-12-31

    The light attenuation and timing characteristics of time-of-flight counters constructed of 3m long scintillating fiber bundles of different shapes and sizes are presented. Fiber bundles made of 5mm diameter fibers showed good timing characteristics and less light attenuation. The results for a 1.5m long scintillator rod are also presented.

  12. Identified-particle production at high-momentum with the HMPID detector in the ALICE experiment at the LHC in proton-proton collisions at √ {s} = 2.76 TeV

    NASA Astrophysics Data System (ADS)

    Barlle, F.

    2012-08-01

    The ALICE experiment is devoted to the study of heavy-ion collisions at LHC energies. ALICE is also studying proton-proton collisions both as a comparison with lead-lead collisions and in physics areas where ALICE is competitive with other LHC experiments. The ALICE-HMPID detector performs charged particle track-by-track identification (π and K in the momentum range of 1 < p < 3 GeV/c and p in 1.5 < p < 5 GeV/c) by means of measurement of Cherenkov angle and momentum information provided by the tracking devices. The current results on hadron transverse momentum spectra measured by the HMPID detector in pp collisions at √ {s} = 2.76 TeV, are shown.

  13. The ALICE-HMPID Detector Control System: Its evolution towards an expert and adaptive system

    NASA Astrophysics Data System (ADS)

    De Cataldo, G.; Franco, A.; Pastore, C.; Sgura, I.; Volpe, G.

    2011-05-01

    The High Momentum Particle IDentification (HMPID) detector is a proximity focusing Ring Imaging Cherenkov (RICH) for charged hadron identification. The HMPID is based on liquid C 6F 14 as the radiator medium and on a 10 m 2 CsI coated, pad segmented photocathode of MWPCs for UV Cherenkov photon detection. To ensure full remote control, the HMPID is equipped with a detector control system (DCS) responding to industrial standards for robustness and reliability. It has been implemented using PVSS as Slow Control And Data Acquisition (SCADA) environment, Programmable Logic Controller as control devices and Finite State Machines for modular and automatic command execution. In the perspective of reducing human presence at the experiment site, this paper focuses on DCS evolution towards an expert and adaptive control system, providing, respectively, automatic error recovery and stable detector performance. HAL9000, the first prototype of the HMPID expert system, is then presented. Finally an analysis of the possible application of the adaptive features is provided.

  14. Time-of-flight technique for particle identification at energies from 2 to 400 keV/nucleon

    NASA Technical Reports Server (NTRS)

    Gloeckler, G.; Hsieh, K. C.

    1979-01-01

    The time of flight technique for particle identification was extended to 2 keV/nucleon and the size of the start-time detector was reduced considerably by the use of carbon foils of few micrograms/cm square in thickness combined with microchannel plates for detecting secondary electrons. Time of flight telescopes incorporating this start-time device were used to measure the stopping power of a number of low energy heavy ions in thin carbon foils and the charge states of these ions emerging from such foils. Applications for the detection and identification of low energy interplanetary and magnetospheric particles are suggested.

  15. National Ignition Facility neutron time-of-flight measurements (invited)a)

    NASA Astrophysics Data System (ADS)

    Lerche, R. A.; Glebov, V. Yu.; Moran, M. J.; McNaney, J. M.; Kilkenny, J. D.; Eckart, M. J.; Zacharias, R. A.; Haslam, J. J.; Clancy, T. J.; Yeoman, M. F.; Warwas, D. P.; Sangster, T. C.; Stoeckl, C.; Knauer, J. P.; Horsfield, C. J.

    2010-10-01

    The first 3 of 18 neutron time-of-flight (nTOF) channels have been installed at the National Ignition Facility (NIF). The role of these detectors includes yield, temperature, and bang time measurements. This article focuses on nTOF data analysis and quality of results obtained for the first set of experiments to use all 192 NIF beams. Targets produced up to 2×1010 2.45 MeV neutrons for initial testing of the nTOF detectors. Differences in neutron scattering at the OMEGA laser facility where the detectors were calibrated and at NIF result in different response functions at the two facilities. Monte Carlo modeling shows this difference. The nTOF performance on these early experiments indicates that the nTOF system with its full complement of detectors should perform well in future measurements of yield, temperature, and bang time.

  16. National Ignition Facility (NIF) Neutron time-of-flight (nTOF) Measurements

    SciTech Connect

    Lerche, R A; Glebov, V Y; Moran, M J; McNaney, J M; Kilkenny, J D; Eckart, M; Zacharias, R A; Haslam, J J; Clancy, T J; Yeoman, M F; Warwas, D P; Sangster, T C; Stoeckl, C; Knauer, J; Horsfield, C J

    2010-05-13

    The first three of eighteen neutron time-of-flight (nTOF) channels have been installed at the National Ignition Facility (NIF). The role of these detectors includes yield, temperature, and bang time measurements. This article focuses on nTOF data analysis and quality of results obtained for the first set of experiments to use all 192 NIF beams. Targets produced up to 2 x 10{sup 10} 2.45-MeV neutrons for initial testing of the nTOF detectors. Differences in neutron scattering at the OMEGA laser facility where the detectors were calibrated and at NIF result in different response functions at the two facilities. Monte Carlo modeling shows this difference. The nTOF performance on these early experiments indicates the nTOF system with its full complement of detectors should perform well in future measurements of yield, temperature, and bang time.

  17. The ALICE Electromagnetic Calorimeter

    SciTech Connect

    Gadrat, S.

    2010-06-01

    ALICE (A Large Ion Collider Experiment) is the only LHC experiment at CERN fully dedicated to the study of the quark and gluon plasma. Driven by the RHIC results on jet quenching, the ALICE collaboration has proposed to extend the capabilities of the ALICE detector for the study of high momentum photons and jets by adding a large acceptance calorimeter. This EMCal (ElectroMagnetic Calorimeter) is designed to provide an unbiased fast high-p{sub T} trigger and to measure the neutral energy of jets and photons up to 200 GeV. Four over ten supermodules of the calorimeter have been installed and commissioned at CERN in 2009 which represents 40% of the full acceptance.

  18. Application of the Monte Carlo methods and variational procedure for optimizing time-of-flight neutron diffractometer characteristics

    NASA Astrophysics Data System (ADS)

    Khrushchinsky, A. A.; Kuten, S. A.; Viarenich, K. A.; Speransky, P. A.

    2016-05-01

    Based on variational calculus, a procedure for the optimal approximation of detector surface of the time-of-flight neutron diffractometer has been suggested. The exact solution for a point sample and zero thickness detector has been obtained. Using the shape of the detector surface, an optimized Monte Carlo simulation has been performed for the parameters of the spectrometer depending on the sample size and detector thickness, its azimuthal and Bragg's angular dimensions, and taking into account the neutron absorption in the sample and detector.

  19. Time-of-flight spectroscopy: energy calibration and consistensy check

    NASA Astrophysics Data System (ADS)

    Stunault, A.; Andersen, K. H.; Blanc, Y.; Fåk, B.; Godfrin, H.; Guckelsberger, K.; Scherm, R.

    1992-06-01

    A method for calibration of the energy transfers at a time-of-flight (TOF) spectrometer is presented: flight pamths and wavelength are determined to 10 -3 using the arrival times of neutron pulses and prompt capture γs from the sample. We also developed a method to check the reproducibility of a series of TFO data sets, each with over 50 000 data points.

  20. Time-of-flight direct recoil ion scattering spectrometer

    DOEpatents

    Krauss, A.R.; Gruen, D.M.; Lamich, G.J.

    1994-09-13

    A time-of-flight direct recoil and ion scattering spectrometer beam line is disclosed. The beam line includes an ion source which injects ions into pulse deflection regions and separated by a drift space. A final optics stage includes an ion lens and deflection plate assembly. The ion pulse length and pulse interval are determined by computerized adjustment of the timing between the voltage pulses applied to the pulsed deflection regions. 23 figs.

  1. A Segmented Time-of-Flight Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    Srivastava, S. K.; Iga, I.; Rao, M. V. V. S.

    1995-01-01

    The present paper describes the design of a time-of-flight mass spectrometer (TOFMS) in which the single flight tube of a conventional TOFMS has been replaced by several cylindrical electrostatic lenses in tandem. By a judicious choice of voltages on these lenses, an improved TOFMS has been realized which has a superior mass and energy resolution, shorter flight lengths, excellent signal-to-noise ratio and less stringent requirements on the bias voltages.

  2. Time-of-flight direct recoil ion scattering spectrometer

    DOEpatents

    Krauss, Alan R.; Gruen, Dieter M.; Lamich, George J.

    1994-01-01

    A time of flight direct recoil and ion scattering spectrometer beam line (10). The beam line (10) includes an ion source (12) which injects ions into pulse deflection regions (14) and (16) separated by a drift space (18). A final optics stage includes an ion lens and deflection plate assembly (22). The ion pulse length and pulse interval are determined by computerized adjustment of the timing between the voltage pulses applied to the pulsed deflection regions (14) and (16).

  3. KELVIN rare gas time-of-flight program

    SciTech Connect

    Vernon, M.

    1981-03-01

    The purpose of this appendix is to explain in detail the procedure for performing time-of-flight (TOF) calibration measurements. The result of the calibration measurements is to assign a correct length (L) to the path the molecules travel in a particular experimental configuration. In conjunction with time information (t) a velocity distribution (L/t) can then be determined. The program KELVIN is listed.

  4. Integration of neutron time-of-flight single-crystal Bragg peaks in reciprocal space

    SciTech Connect

    Schultz, Arthur J; Joergensen, Mads; Wang, Xiaoping; Mikkelson, Ruth L; Mikkelson, Dennis J; Lynch, Vickie E; Peterson, Peter F; Green, Mark L; Hoffmann, Christina

    2014-01-01

    The intensity of single crystal Bragg peaks obtained by mapping neutron time-of-flight event data into reciprocal space and integrating in various ways are compared. These include spherical integration with a fixed radius, ellipsoid fitting and integrating of the peak intensity and one-dimensional peak profile fitting. In comparison to intensities obtained by integrating in real detector histogram space, the data integrated in reciprocal space results in better agreement factors and more accurate atomic parameters. Furthermore, structure refinement using integrated intensities from one-dimensional profile fitting is demonstrated to be more accurate than simple peak-minus-background integration.

  5. Biomark/Organic Analysis with Time-of-Flight Mass Spectrometry

    NASA Technical Reports Server (NTRS)

    Waite, J. Hunter, Jr.

    2004-01-01

    The concept of a Comprehensive 2-Dimensional Gas Chromatography coupled with Time-of-Flight Mass Spectrometry (GCxGC-TOWS) for the analysis of organic compounds has been proven with commercially available instrumentation (LECO Corp). The performance of a GCxGC instrument has been characterized in various stages using two independent breadboard systems. The GCxGC separation systems, including the thermal modulator, have been miniaturized to the size of a benchtop configuration. One breadboard system employs a Flame Ionization Detector (FID), whereas the second breadboard system employs a Time-of-Fight mass spectrometer (TOFWS) as a detection system.

  6. Multivariate Sensitivity Analysis of Time-of-Flight Sensor Fusion

    NASA Astrophysics Data System (ADS)

    Schwarz, Sebastian; Sjöström, Mårten; Olsson, Roger

    2014-09-01

    Obtaining three-dimensional scenery data is an essential task in computer vision, with diverse applications in various areas such as manufacturing and quality control, security and surveillance, or user interaction and entertainment. Dedicated Time-of-Flight sensors can provide detailed scenery depth in real-time and overcome short-comings of traditional stereo analysis. Nonetheless, they do not provide texture information and have limited spatial resolution. Therefore such sensors are typically combined with high resolution video sensors. Time-of-Flight Sensor Fusion is a highly active field of research. Over the recent years, there have been multiple proposals addressing important topics such as texture-guided depth upsampling and depth data denoising. In this article we take a step back and look at the underlying principles of ToF sensor fusion. We derive the ToF sensor fusion error model and evaluate its sensitivity to inaccuracies in camera calibration and depth measurements. In accordance with our findings, we propose certain courses of action to ensure high quality fusion results. With this multivariate sensitivity analysis of the ToF sensor fusion model, we provide an important guideline for designing, calibrating and running a sophisticated Time-of-Flight sensor fusion capture systems.

  7. A Compact Liquid Xenon Compton Telescope with High Energy Resolution and Time-of-Flight

    NASA Astrophysics Data System (ADS)

    Oberlack, Uwe; Gomez, R.; Olsen, C.; Shagin, P.; Aprile, E.; Giboni, K.; Plante, G.; Santorelli, R.

    2006-09-01

    Two recent developments have led us to propose a new type of Compton telescope in compact geometry with time-of-flight, for gamma-ray astronomy in the energy regime of 0.2 - 10 MeV. First, the technology of vacuum ultraviolet photosensors for efficient and fast readout of liquid xenon (LXe) scintillation light has improved dramatically over the last few years, and new developments are underway. A LXe Advanced Compton Telescope would consist of two detector arrays of LXe time projection chambers in compact geometry, with time-of-flight (ToF) between detector modules at a resolution of order 100 ps. Second, the previously achieved moderate energy resolution in LXe, a significant draw-back for gamma-ray line spectroscopy, has been found to be largely due to a strong anti-correlation of ionization and scintillation in LXe. Efficient measurement of both charge and light enables us to improve energy resolution greatly. A factor of three improvement over a previous prototype, LXeGRIT, has already been achieved, and the measured underlying physics indicate the possibility of achievng energy resolution below 1% FWHM at 1 MeV. We are vigorously working on improving light and charge readout to realize this potential in a practical detector. We report on the status and prospects of our current research and development program. This work is supported by NASA grant NNG05WC24G.

  8. A Fast Pulsed Neutron Source for Time-of-Flight Detection of Nuclear Materials and Explosives

    SciTech Connect

    Krishnan, Mahadevan; Bures, Brian; James, Colt; Madden, Robert; Hennig, Wolfgang; Breus, Dimitry; Asztalos, Stephen; Sabourov, Konstantin; Lane, Stephen

    2011-12-13

    AASC has built a fast pulsed neutron source based on the Dense Plasma Focus (DPF). The more current version stores only 100 J but fires at {approx}10-50 Hz and emits {approx}10{sup 6}n/pulse at a peak current of 100 kA. Both sources emit 2.45{+-}0.1 MeV(DD) neutron pulses of {approx}25-40 ns width. Such fast, quasi-monoenergetic pulses allow time-of-flight detection of characteristic emissions from nuclear materials or high explosives. A test is described in which iron targets were placed at different distances from the point neutron source. Detectors such as Stilbene and LaBr3 were used to capture inelastically induced, 847 keV gammas from the iron target. Shielding of the source and detectors eliminated most (but not all) of the source neutrons from the detectors. Gated detection, pulse shape analysis and time-of-flight discrimination enable separation of gamma and neutron signatures and localization of the target. A Monte Carlo simulation allows evaluation of the potential of such a fast pulsed source for a field-portable detection system. The high rep-rate source occupies two 200 liter drums and uses a cooled DPF Head that is <500 cm{sup 3} in volume.

  9. Lanthanum halide scintillators for time-of-flight 3-D pet

    DOEpatents

    Karp, Joel S.; Surti, Suleman

    2008-06-03

    A Lanthanum Halide scintillator (for example LaCl.sub.3 and LaBr.sub.3) with fast decay time and good timing resolution, as well as high light output and good energy resolution, is used in the design of a PET scanner. The PET scanner includes a cavity for accepting a patient and a plurality of PET detector modules arranged in an approximately cylindrical configuration about the cavity. Each PET detector includes a Lanthanum Halide scintillator having a plurality of Lanthanum Halide crystals, a light guide, and a plurality of photomultiplier tubes arranged respectively peripherally around the cavity. The good timing resolution enables a time-of-flight (TOF) PET scanner to be developed that exhibits a reduction in noise propagation during image reconstruction and a gain in the signal-to-noise ratio. Such a PET scanner includes a time stamp circuit that records the time of receipt of gamma rays by respective PET detectors and provides timing data outputs that are provided to a processor that, in turn, calculates time-of-flight (TOF) of gamma rays through a patient in the cavity and uses the TOF of gamma rays in the reconstruction of images of the patient.

  10. Analysis of megadalton ions using cryodetection MALDI time-of-flight mass spectrometry.

    PubMed

    Wenzel, Ryan J; Matter, Urs; Schultheis, Lothar; Zenobi, Renato

    2005-07-15

    Presented are initial results from the first commercially available matrix-assisted laser desorption/ionization time-of-flight mass spectrometer specifically designed for the sensitive detection of very high mass ions (macromizer, Comet AG). This new instrument utilizes a 16-element superconducting tunnel junction detector coupled with a fully adjustable gimbal-mounted ion source/focusing region that allows unparalleled sensitivity for detection of singly charged high molecular weight ions. Using this new technology, the singly charged ions in the megadalton region are detected from immunoglobulin M and von Willebrand factor proteins. This detector technology also measures the kinetic energy of the particles impacting the detector, which can be correlated to the charge of the particles. Immunoglobulin G and streptavidin were used to demonstrate the ability of the macromizer instrument to detect high-mass ions and to discern the charge state of the ions. PMID:16013843

  11. Background optimization for the neutron time-of-flight spectrometer NEAT

    NASA Astrophysics Data System (ADS)

    Günther, G.; Russina, M.

    2016-08-01

    The neutron time-of-flight spectrometer NEAT at BER II is currently undergoing a major upgrade where an important aspect is the prevention of parasitic scattering to enhance the signal-to-noise ratio. Here, we discuss the impact of shielding to suppress parasitic scattering from two identified sources of background: the sample environment and detector tubes. By means of Monte Carlo simulations and a modification of the analytical model of Copley et al. [Copley and Cook, 1994], the visibility functions of instrument parts are computed for different shielding configurations. According to three selection criteria, namely suppression of background, transmission and detection limit, the parameters of an oscillating radial collimator are optimized for NEAT's default setup. Moreover, different configurations of detector shielding are discussed to prevent cross-talk within the radial detector system.

  12. ALICE Collaboration

    NASA Astrophysics Data System (ADS)

    Abelev, B.; Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agostinelli, A.; Agrawal, N.; Ahammed, Z.; Ahmad, N.; Ahmed, I.; Ahn, S. U.; Ahn, S. A.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Alam, S. N.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baltasar Dos Santos Pedrosa, F.; Baral, R. C.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Baumann, C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont, R.; Belmont-Moreno, E.; Belyaev, V.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Berger, M. E.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Bjelogrlic, S.; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Böhmer, F. V.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Bossú, F.; Botje, M.; Botta, E.; Böttger, S.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Calero Diaz, L.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Carena, F.; Carena, W.; Castillo Castellanos, J.; Casula, E. A. R.; Catanescu, V.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortese, P.; Cortés Maldonado, I.; Cosentino, M. R.; Costa, F.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dainese, A.; Danu, A.; Das, D.; Das, I.; Das, K.; Das, S.; Dash, A.; Dash, S.; De, S.; Delagrange, H.; Deloff, A.; Dénes, E.; D'Erasmo, G.; De Caro, A.; de Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; de Rooij, R.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Di Bari, D.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Dørheim, S.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Dutta Majumdar, A. K.; Hilden, T. E.; Ehlers, R. J.; Elia, D.; Engel, H.; Erazmus, B.; Erdal, H. A.; Eschweiler, D.; Espagnon, B.; Esposito, M.; Estienne, M.; Esumi, S.; Evans, D.; Evdokimov, S.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fehlker, D.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Floratos, E.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Furs, A.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Garishvili, I.; Gerhard, J.; Germain, M.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Gladysz-Dziadus, E.; Glässel, P.; Gomez Ramirez, A.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Graczykowski, L. K.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Guilbaud, M.; Gulbrandsen, K.; Gulkanyan, H.; Gumbo, M.; Gunji, T.; Gupta, A.; Gupta, R.; Khan, K. H.; Haake, R.; Haaland, Ø.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.

    2014-11-01

    The ALICE Collaboration would like to thank all its engineers and technicians for their invaluable contributions to the construction of the experiment and the CERN accelerator teams for the outstanding performance of the LHC complex.

  13. MAD - Monitoring ALICE Dataflow

    NASA Astrophysics Data System (ADS)

    Chibante Barroso, V.; Costa, F.; Grigoras, C.; Wegrzynek, A.

    2015-12-01

    ALICE (A Large Ion Collider Experiment) is the heavy-ion detector designed to study the physics of strongly interacting matter and the quark-gluon plasma at the CERN Large Hadron Collider (LHC). Following a successful Run 1, which ended in February 2013, the ALICE data acquisition (DAQ) entered a consolidation phase to prepare for Run 2 which will start in the beginning of 2015. A new software tool has been developed by the data acquisition project to improve the monitoring of the experiment's dataflow, from the data readout in the DAQ farm up to its shipment to CERN's main computer centre. This software, called ALICE MAD (Monitoring ALICE Dataflow), uses the MonALISA framework as core module to gather, process, aggregate and distribute monitoring values from the different processes running in the distributed DAQ farm. Data are not only pulled from the data sources to MAD but can also be pushed by dedicated data collectors or the data source processes. A large set of monitored metrics (from the backpressure status on the readout links to event counters in each of the DAQ nodes and aggregated data rates for the whole data acquisition) is needed to provide a comprehensive view of the DAQ status. MAD also injects alarms in the Orthos alarm system whenever abnormal conditions are detected. The MAD web-based GUI uses WebSockets to provide dynamic and on-time status displays for the ALICE shift crew. Designed as a widget-based system, MAD supports an easy integration of new visualization blocks and also customization of the information displayed to the shift crew based on the ALICE activities.

  14. Continuous time-of-flight ion mass spectrometer

    DOEpatents

    Funsten, Herbert O.; Feldman, William C.

    2004-10-19

    A continuous time-of-flight mass spectrometer having an evacuated enclosure with means for generating an electric field located in the evacuated enclosure and means for injecting a sample material into the electric field. A source of continuous ionizing radiation injects ionizing radiation into the electric field to ionize atoms or molecules of the sample material, and timing means determine the time elapsed between arrival of a secondary electron out of said ionized atoms or molecules at a first predetermined location and arrival of a sample ion out of said ionized atoms or molecules at a second predetermined location.

  15. The Berlin time-of-flight ERDA setupe

    NASA Astrophysics Data System (ADS)

    Bohne, W.; Röhrich, J.; Röschert, G.

    1998-03-01

    The new mass and energy dispersive Elastic Recoil Detection Analysis (ERDA) spectrometer located at a high-energy target position of the heavy-ion-beam laboratory (ISL) of the Hahn-Meitner-Institut Berlin is presented. Many different projectile ions from hydrogen to xenon with variable energies up to several MeV/u are available. The recoil identification is done by means of a time-of-flight (TOF) energy setup with a relatively large solid angle of 1.57 msr. Due to the long flight path of 123 cm and a time resolution of about 180 ps, a good mass and depth resolution can be achieved.

  16. Time-of-Flight Tip-Clearance Measurements

    NASA Technical Reports Server (NTRS)

    Dhadwal, H. S.; Kurkov, A. P.; Janetzke, D. C.

    1999-01-01

    In this paper a time-of-flight probe system incorporating the two integrated fiber optic probes which are tilted equally relative to the probe holder centerline, is applied for the first time to measure the tip clearance of an advanced fan prototype. Tip clearance is largely independent of the signal amplitude and it relies on timing measurement. This work exposes optical effects associated with the fan blade stagger angle that were absent during the original spin-rig experiment on the zero stagger rotor. Individual blade tip clearances were measured with accuracy of +/- 127-mm (+/- 0.005-in). Probe features are discussed and improvements to the design are suggested.

  17. Time-of-flight flow imaging using NMR remote detection

    SciTech Connect

    Granwehr, Josef; Harel, Elad; Han, Song-I; Garcia, Sandra; Pines,Alex; Sen, Pabitra N.; Song, Yi-Qiao

    2005-05-05

    A time-of-flight imaging technique is introduced to visualize fluid flow and dispersion through porous media using NMR. As the fluid flows through a sample, the nuclear spin magnetization is modulated by RF pulses and magnetic field gradients to encode the spatial coordinates of the fluid. When the fluid leaves the sample, its magnetization is recorded by a second RF coil. This scheme not only facilitates a time-dependent imaging of fluid flow, it also allows a separate optimization of encoding and detection subsystems to enhance overall sensitivity. The technique is demonstrated by imaging gas flow through a porous rock.

  18. Central diffraction at ALICE

    NASA Astrophysics Data System (ADS)

    Lämsä, J. W.; Orava, R.

    2011-02-01

    The ALICE experiment is shown to be well suited for studies of exclusive final states from central diffractive reactions. The gluon-rich environment of the central system allows detailed QCD studies and searches for exotic meson states, such as glueballs, hybrids and new charmonium-like states. It would also provide a good testing ground for detailed studies of heavy quarkonia. Due to its central barrel performance, ALICE can accurately measure the low-mass central systems with good purity. The efficiency of the Forward Multiplicity Detector (FMD) and the Forward Shower Counter (FSC) system for detecting rapidity gaps is shown to be adequate for the proposed studies. With this detector arrangement, valuable new data can be obtained by tagging central diffractive processes.

  19. Time of flight Laue fiber diffraction studies of perdeuterated DNA

    SciTech Connect

    Forsyth, V.T.; Whalley, M.A.; Mahendrasingam, A.; Fuller, W.

    1994-12-31

    The diffractometer SXD at the Rutherford Appleton Laboratory ISIS pulsed neutron source has been used to record high resolution time-of-flight Laue fiber diffraction data from DNA. These experiments, which are the first of their kind, were undertaken using fibers of DNA in the A conformation and prepared using deuterated DNA in order to minimis incoherent background scattering. These studies complement previous experiments on instrument D19 at the Institute Laue Langevin using monochromatic neutrons. Sample preparation involved drawing large numbers of these deuterated DNA fibers and mounting them in a parallel array. The strategy of data collection is discussed in terms of camera design, sample environment and data collection. The methods used to correct the recorded time-of-flight data and map it into the final reciprocal space fiber diffraction dataset are also discussed. Difference Fourier maps showing the distribution of water around A-DNA calculated on the basis of these data are compared with results obtained using data recorded from hydrogenated A-DNA on D19. Since the methods used for sample preparation, data collection and data processing are fundamentally different for the monochromatic and Laue techniques, the results of these experiments also afford a valuable opportunity to independently test the data reduction and analysis techniques used in the two methods.

  20. Inductively Coupled Plasma Zoom-Time-of-Flight Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Dennis, Elise A.; Ray, Steven J.; Enke, Christie G.; Hieftje, Gary M.

    2016-03-01

    A zoom-time-of-flight mass spectrometer has been coupled to an inductively coupled plasma (ICP) ionization source. Zoom-time-of-flight mass spectrometry (zoom-TOFMS) combines two complementary types of velocity-based mass separation. Specifically, zoom-TOFMS alternates between conventional, constant-energy acceleration (CEA) TOFMS and energy-focused, constant-momentum acceleration (CMA) (zoom) TOFMS. The CMA mode provides a mass-resolution enhancement of 1.5-1.7× over CEA-TOFMS in the current, 35-cm ICP-zoom-TOFMS instrument geometry. The maximum resolving power (full-width at half-maximum) for the ICP-zoom-TOFMS instrument is 1200 for CEA-TOFMS and 1900 for CMA-TOFMS. The CMA mode yields detection limits of between 0.02 and 0.8 ppt, depending upon the repetition rate and integration time—compared with single ppt detection limits for CEA-TOFMS. Isotope-ratio precision is shot-noise limited at approximately 0.2% relative-standard deviation (RSD) for both CEA- and CMA-TOFMS at a 10 kHz repetition rate and an integration time of 3-5 min. When the repetition rate is increased to 43.5 kHz for CMA, the shot-noise limited, zoom-mode isotope-ratio precision is improved to 0.09% RSD for the same integration time.

  1. Quasi-dynamic mode of nanomembranes for time-of-flight mass spectrometry of proteins.

    PubMed

    Park, Jonghoo; Kim, Hyunseok; Blick, Robert H

    2012-04-21

    Mechanical resonators realized on the nano-scale by now offer applications in mass-sensing of biomolecules with extraordinary sensitivity. The general idea is that perfect mechanical biosensors should be of extremely small size to achieve zeptogram sensitivity in weighing single molecules similar to a balance. However, the small scale and long response time of weighing biomolecules with a cantilever restrict their usefulness as a high-throughput method. Commercial mass spectrometry (MS) such as electro-spray ionization (ESI)-MS and matrix-assisted laser desorption/ionization (MALDI)-time of flight (TOF)-MS are the gold standards to which nanomechanical resonators have to live up to. These two methods rely on the ionization and acceleration of biomolecules and the following ion detection after a mass selection step, such as time-of-flight (TOF). Hence, the spectrum is typically represented in m/z, i.e. the mass to ionization charge ratio. Here, we describe the feasibility and mass range of detection of a new mechanical approach for ion detection in time-of-flight mass spectrometry, the principle of which is that the impinging ion packets excite mechanical oscillations in a silicon nitride nanomembrane. These mechanical oscillations are henceforth detected via field emission of electrons from the nanomembrane. Ion detection is demonstrated in MALDI-TOF analysis over a broad range with angiotensin, bovine serum albumin (BSA), and an equimolar protein mixture of insulin, BSA, and immunoglobulin G (IgG). We find an unprecedented mass range of operation of the nanomembrane detector. PMID:22378023

  2. Development of an ion time-of-flight spectrometer for neutron depth profiling

    NASA Astrophysics Data System (ADS)

    Cetiner, Mustafa Sacit

    Ion time-of-flight spectrometry techniques are investigated for applicability to neutron depth profiling. Time-of-flight techniques are used extensively in a wide range of scientific and technological applications including energy and mass spectroscopy. Neutron depth profiling is a near-surface analysis technique that gives concentration distribution versus depth for certain technologically important light elements. The technique uses thermal or sub-thermal neutrons to initiate (n, p) or (n, alpha) reactions. Concentration versus depth distribution is obtained by the transformation of the energy spectrum into depth distribution by using stopping force tables of the projectiles in the substrate, and by converting the number of counts into concentration using a standard sample of known dose value. Conventionally, neutron depth profiling measurements are based on charged particle spectrometry, which employs semiconductor detectors such as a surface barrier detector (SBD) and the associated electronics. Measurements with semiconductor detectors are affected by a number of broadening mechanisms, which result from the interactions between the projectile ion and the detector material as well as fluctuations in the signal generation process. These are inherent features of the detection mechanism that involve the semiconductor detectors and cannot be avoided. Ion time-of-flight spectrometry offers highly precise measurement capabilities, particularly for slow particles. For high-energy low-mass particles, measurement resolution tends to degrade with all other parameters fixed. The threshold for more precise ion energy measurements with respect to conventional techniques, such as direct energy measurement by a surface barrier detector, is directly related to the design and operating parameters of the device. Time-of-flight spectrometry involves correlated detection of two signals by a coincidence unit. In ion time-of-flight spectroscopy, the ion generates the primary input

  3. Preparing the ALICE DAQ upgrade

    NASA Astrophysics Data System (ADS)

    Carena, F.; Carena, W.; Chapeland, S.; Chibante Barroso, V.; Costa, F.; Dénes, E.; Divià, R.; Fuchs, U.; Grigore, A.; Kiss, T.; Rauch, W.; Rubin, G.; Simonetti, G.; Soós, C.; Telesca, A.; Vande Vyvre, P.; Von Haller, B.

    2012-12-01

    In November 2009, after 15 years of design and installation, the ALICE experiment started to detect and record the first collisions produced by the LHC. It has been collecting hundreds of millions of events ever since with both proton and heavy ion collisions. The future scientific programme of ALICE has been refined following the first year of data taking. The physics targeted beyond 2018 will be the study of rare signals. Several detectors will be upgraded, modified, or replaced to prepare ALICE for future physics challenges. An upgrade of the triggering and readout systems is also required to accommodate the needs of the upgraded ALICE and to better select the data of the rare physics channels. The ALICE upgrade will have major implications in the detector electronics and controls, data acquisition, event triggering and offline computing and storage systems. Moreover, the experience accumulated during more than two years of operation has also lead to new requirements for the control software. We will review all these new needs and the current R&D activities to address them. Several papers of the same conference present in more details some elements of the ALICE online system.

  4. Study of cosmic ray events with high muon multiplicity using the ALICE detector at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    The ALICE Collaboration

    2016-01-01

    ALICE is one of four large experiments at the CERN Large Hadron Collider near Geneva, specially designed to study particle production in ultra-relativistic heavy-ion collisions. Located 52 meters underground with 28 meters of overburden rock, it has also been used to detect muons produced by cosmic ray interactions in the upper atmosphere. In this paper, we present the multiplicity distribution of these atmospheric muons and its comparison with Monte Carlo simulations. This analysis exploits the large size and excellent tracking capability of the ALICE Time Projection Chamber. A special emphasis is given to the study of high multiplicity events containing more than 100 reconstructed muons and corresponding to a muon areal density ρμ > 5.9 m-2. Similar events have been studied in previous underground experiments such as ALEPH and DELPHI at LEP. While these experiments were able to reproduce the measured muon multiplicity distribution with Monte Carlo simulations at low and intermediate multiplicities, their simulations failed to describe the frequency of the highest multiplicity events. In this work we show that the high multiplicity events observed in ALICE stem from primary cosmic rays with energies above 1016 eV and that the frequency of these events can be successfully described by assuming a heavy mass composition of primary cosmic rays in this energy range. The development of the resulting air showers was simulated using the latest version of QGSJET to model hadronic interactions. This observation places significant constraints on alternative, more exotic, production mechanisms for these events.

  5. Studies for dimuon measurement with ALICE

    SciTech Connect

    Jouan, D.

    1995-07-15

    The idea of measuring dimuon in the ALICE detector is not new, since it already appeared in the Aachen Conference. In the meantime studies were aiming at the use of the two detectors of LHC p-p physics, CMS and ATLAS, already dedicated to dimuon measurement, for these same measurements in heavy ion collisions, whereas the detector dedicated to heavy ions physics at LHC, ALICE, was considering all the other observables. Recently, the interest for dimuon measurements in ALICE was renewed by demands from LHC committee, stiring the activities of a working group in the ALICE collaboration, also associated to a more recent move from new groups. In the following the author briefly describes the interest of measuring dimuons in heavy ion collisions, particularly in ALICE, then the experimental strategy and first estimates of the performances that could be reached with the proposed system.

  6. Data acquisition schemes for continuous two-particle time-of-flight coincidence experiments.

    PubMed

    Bodi, Andras; Sztáray, Bálint; Baer, Tomas; Johnson, Melanie; Gerber, Thomas

    2007-08-01

    Three data acquisition schemes for two-particle coincidence experiments with a continuous source are discussed. The single-start/single-stop technique, implemented with a time-to-pulse-height converter, results in a complicated spectrum and breaks down severely at high count rates. The single-start/multiple-stop setup, based on a time-to-digital converter and the first choice in today's similar coincidence experiments, performs significantly better at high count rates, but its performance is still hampered if the time-of-flight range is large, and the false coincidence background is variable if the event frequency and the collection efficiency of the starts are both high. A straightforward, multistart/multistop setup is proposed for coincidence experiments. By collecting all detector data, it ensures the highest signal-to-noise ratio, constant background, and fast data acquisition and can now be easily constructed with commercially available time-to-digital converters. Analytical and numerically evaluated formulas are derived to characterize the performance of each setup in a variety of environments. Computer simulated spectra are presented to illustrate the analytically predicted features of the various raw time-of-flight distributions obtained with each technique. PMID:17764338

  7. Determination of phenylalanine isotope ratio enrichment by liquid chromatography/time- of-flight mass spectrometry.

    PubMed

    Wu, Zhanpin; Zhang, Xiao-Jun; Cody, Robert B; Wolfe, Robert R

    2004-01-01

    The application of time-of-flight mass spectrometry to isotope ratio measurements has been limited by the relatively low dynamic range of the time-to-digital converter detectors available on commercial LC/ToF-MS systems. Here we report the measurement of phenylalanine isotope ratio enrichment by using a new LC/ToF-MS system with wide dynamic range. Underivatized phenylalanine was injected onto a C18 column directly with 0.1% formic acid/acetonitrile as the mobile phase. The optimal instrument parameters for the time-of-flight mass spectrometer were determined by tuning the instrument with a phenylalanine standard. The accuracy of the isotope enrichment measurement was determined by the injection of standard solutions with known isotope ratios ranging from 0.02% to 9.2%. A plot of the results against the theoretical values gave a linear curve with R2 of 0.9999. The coefficient of variation for the isotope ratio measurement was below 2%. The method is simple, rapid, and accurate and presents an attractive alternative to traditional GC/MS applications. PMID:15531795

  8. Time-of-flight Extreme Environment Diffractometer at the Helmholtz-Zentrum Berlin

    SciTech Connect

    Prokhnenko, Oleksandr Stein, Wolf-Dieter; Bleif, Hans-Jürgen; Fromme, Michael; Bartkowiak, Maciej; Wilpert, Thomas

    2015-03-15

    The Extreme Environment Diffractometer (EXED) is a new neutron time-of-flight instrument at the BER II research reactor at the Helmholtz-Zentrum Berlin, Germany. Although EXED is a special-purpose instrument, its early construction made it available for users as a general-purpose diffractometer. In this respect, EXED became one of the rare examples, where the performance of a time-of-flight diffractometer at a continuous source can be characterized. In this paper, we report on the design and performance of EXED with an emphasis on the unique instrument capabilities. The latter comprise variable wavelength resolution and wavelength band, control of the incoming beam divergence, the possibility to change the angular positions of detectors and their distance to the sample, and use of event recording and offline histogramming. These features combined make EXED easily tunable to the requirements of a particular problem, from conventional diffraction to small angle neutron scattering. The instrument performance is demonstrated by several reference measurements and user experiments.

  9. Neutron Inelastic Scattering Mechanism and Measurement of Neutron Asymmetry Using Time of Flight Technique

    NASA Astrophysics Data System (ADS)

    Al Azzawe, A. J. M.

    2007-02-01

    Inelastic scattering is an essential reaction for other nuclear reactions to detect the optical model and compound nucleus formation within the range of (0.4- 5.0) MeV neutron incident energy by using time of flight technique. The time of flight system (TOFS) installed on the horizontal channel reactor RRA has been used to measure the asymmetry of scattered fast neutrons, when data acquisition and system control were recorded event by event by HP — computer via CAMAC system. Eight NE 213 neutron counters were used in order to detect neutron inelastic scattering in the forward direction (4 neutron counters at 0° angle) and in the backward direction (4 neutron counters at 180° angle) to measure the asymmetry of fast neutron. Each neutron counter was 50cm in length and 8cm in diameter, viewed by two (58 — DVP) photomultiplier tubes. The contribution of direct interaction to the compound nucleus formation was deduced from the asymmetry in the neutron detection at the same direction of these eight neutron counters. A time resolution of 8.2 ns between the eight neutron counters and one of the two Ge(Li) detectors has been obtained.

  10. Time-of-flight Extreme Environment Diffractometer at the Helmholtz-Zentrum Berlin.

    PubMed

    Prokhnenko, Oleksandr; Stein, Wolf-Dieter; Bleif, Hans-Jürgen; Fromme, Michael; Bartkowiak, Maciej; Wilpert, Thomas

    2015-03-01

    The Extreme Environment Diffractometer (EXED) is a new neutron time-of-flight instrument at the BER II research reactor at the Helmholtz-Zentrum Berlin, Germany. Although EXED is a special-purpose instrument, its early construction made it available for users as a general-purpose diffractometer. In this respect, EXED became one of the rare examples, where the performance of a time-of-flight diffractometer at a continuous source can be characterized. In this paper, we report on the design and performance of EXED with an emphasis on the unique instrument capabilities. The latter comprise variable wavelength resolution and wavelength band, control of the incoming beam divergence, the possibility to change the angular positions of detectors and their distance to the sample, and use of event recording and offline histogramming. These features combined make EXED easily tunable to the requirements of a particular problem, from conventional diffraction to small angle neutron scattering. The instrument performance is demonstrated by several reference measurements and user experiments. PMID:25832206

  11. Time-of-flight MeV-SIMS with beam induced secondary electron trigger

    NASA Astrophysics Data System (ADS)

    Schulte-Borchers, Martina; Döbeli, Max; Müller, Arnold Milenko; George, Matthias; Synal, Hans-Arno

    2016-08-01

    A new Time-of-flight MeV Secondary Ion Mass Spectrometry (MeV-SIMS) setup was developed to be used with a capillary microprobe for molecular imaging with heavy primary ions at MeV energies. Due to the low output current of the ion collimating capillary a Time-of-flight (ToF) measurement method with high duty cycle is necessary. Secondary electrons from the sample surface and transmitted ions were studied as start signals. They enable measurements with a continuous primary beam and unpulsed ToF spectrometer. Tests with various primary ion beams and sample types have shown that a secondary electron signal is obtained from 30% to 40% of incident MeV particles. This provides a ToF start signal with considerably better time resolution than the one obtained from transmitted primary ions detected in a radiation hard gas ionization detector. Beam induced secondary electrons therefore allow for MeV-SIMS measurements with reasonable mass resolution at primary ion beam currents in the low fA range.

  12. Contribution of time-of-flight information to limited-angle positron tomography

    SciTech Connect

    Macdonald, B.; Perez-Mendez, V.; Tam, K.C.

    1981-10-01

    Limited-angle emission tomography was investigated using a two-dimensional phantom to generate positron events simulating a camera with two opposed parallel position-sensitive detectors collecting data within a 90/sup 0/ cone. The data, backprojected onto lines passing through the phantom volume, is used with a matrix reconstruction method to provide two-dimensional images. Image quality was measured using the standard deviation of the reconstructions with respect to the original phantom. The application of Phillips-Twomey smoothing to the deconvolution matrices has substantially improved the original reconstructions, a factor of 1.9 in signal to noise ratio, giving S/N = 3.4 for a phantom having an average of 150 events/pixel. Using photon time-of-flight to restrict the reconstruction volume a further considerable improvement is made. When the time-of-flight limited the contributing volume to 4 lines out of 11 the improvement was another factor of 1.9 giving S/N = 6.0 for the same phantom. Comparable increases in signal to noise ratios are expected for three-dimensional reconstructions.

  13. Fast neutron measurements at the nELBE time-of-flight facility

    NASA Astrophysics Data System (ADS)

    Junghansa, A. R.; Beyer, R.; Grosse, E.; Hannaske, R.; Kögler, T.; Massarczyk, R.; Schwengner, R.; Wagner, A.

    2015-05-01

    The compact neutron-time-of-flight facility nELBE at the superconducting electron accelerator ELBE of Helmholtz-Zentrum Dresden-Rossendorf has been rebuilt. A new enlarged experimental hall with a flight path of up to 10 m is available for neutron time-of-flight experiments in the fast energy range from about 50 keV to 10 MeV. nELBE is intended to deliver nuclear data of fast neutron nuclear interactions e.g. for the transmutation of nuclear waste and improvement of neutron physical simulations of innovative nuclear systems. The experimental programme consists of transmission measurements of neutron total cross sections, elastic and inelastic scattering cross section measurements, and neutron induced fission cross sections. The inelastic scattering to the first few excited states in 56Fe was investigated by measuring the gamma production cross section with an HPGe detector. The neutron induced fission of 242Pu was studied using fast ionisation chambers with large homogeneous actinide deposits.

  14. A time-of-flight spectrometer for detection of low-energy hydrogen atoms

    NASA Astrophysics Data System (ADS)

    van Toledo, W.; de Bree, A. R.; van Buuren, R.; de Kluiver, H.; Donné, A. J. H.

    1990-01-01

    This article deals with an application of the technique of converting hydrogen atoms into negative ions on a low-work-function surface, which is similar to the method nowadays utilized in H- surface sources. This conversion technique is the basis for a time-of-flight spectrometer, for which a proof of principle has recently been established. The conversion takes place on a tungsten (110) crystal target that is covered with cesium. By mounting this target in the detector part of the spectrometer, this apparatus is made sensitive to hydrogen atoms that have energy in the range 10-1000 eV. This feature makes the spectrometer a very powerful and unique tool for detection of low-energy hydrogen atoms. It is, for instance, capable of detecting low-energy hydrogen atoms that are emitted from the edge of a tokamak plasma, and therefore it can yield information on the hydrogen recycling inside the tokamak and hence on the energy balance of the plasma. In the paper we discuss the principle of the detection method, along with a presentation of some time-of-flight spectra that have been obtained from a tokamak plasma.

  15. Chern numbers hiding in time-of-flight images

    SciTech Connect

    Zhao Erhai; Satija, Indubala I.; Bray-Ali, Noah; Williams, Carl J.; Spielman, I. B.

    2011-12-15

    We present a technique for detecting topological invariants--Chern numbers--from time-of-flight images of ultracold atoms. We show that the Chern numbers of integer quantum Hall states of lattice fermions leave their fingerprints in the atoms' momentum distribution. We analytically demonstrate that the number of local maxima in the momentum distribution is equal to the Chern number in two limiting cases, for large hopping anisotropy and in the continuum limit. In addition, our numerical simulations beyond these two limits show that these local maxima persist for a range of parameters. Thus, an everyday observable in cold atom experiments can serve as a useful tool to characterize and visualize quantum states with nontrivial topology.

  16. Accurate Fiber Length Measurement Using Time-of-Flight Technique

    NASA Astrophysics Data System (ADS)

    Terra, Osama; Hussein, Hatem

    2016-06-01

    Fiber artifacts of very well-measured length are required for the calibration of optical time domain reflectometers (OTDR). In this paper accurate length measurement of different fiber lengths using the time-of-flight technique is performed. A setup is proposed to measure accurately lengths from 1 to 40 km at 1,550 and 1,310 nm using high-speed electro-optic modulator and photodetector. This setup offers traceability to the SI unit of time, the second (and hence to meter by definition), by locking the time interval counter to the Global Positioning System (GPS)-disciplined quartz oscillator. Additionally, the length of a recirculating loop artifact is measured and compared with the measurement made for the same fiber by the National Physical Laboratory of United Kingdom (NPL). Finally, a method is proposed to relatively correct the fiber refractive index to allow accurate fiber length measurement.

  17. Inverse time-of-flight spectrometer for beam plasma research

    SciTech Connect

    Yushkov, Yu. G. Zolotukhin, D. B.; Tyunkov, A. V.; Oks, E. M.

    2014-08-15

    The paper describes the design and principle of operation of an inverse time-of-flight spectrometer for research in the plasma produced by an electron beam in the forevacuum pressure range (5–20 Pa). In the spectrometer, the deflecting plates as well as the drift tube and the primary ion beam measuring system are at high potential with respect to ground. This provides the possibility to measure the mass-charge constitution of the plasma created by a continuous electron beam with a current of up to 300 mA and electron energy of up to 20 keV at forevacuum pressures in the chamber placed at ground potential. Research results on the mass-charge state of the beam plasma are presented and analyzed.

  18. Time-of-flight neutral particle analyzer and calibration

    SciTech Connect

    Harris, W. S.; Garate, E. P.; Heidbrink, W. W.; McWilliams, R.; Roche, T.; Trask, E.; Zhang Yang

    2008-10-15

    A time-of-flight diagnostic has been implemented on the Irvine field reversed configuration (IFRC) to obtain an energy distribution function from charge-exchanged neutral hydrogen. The diagnostic includes a 13 cm radius slotted disk rotating at 165 Hz in vacuum which chops the emitted neutrals at a rate of 26 kHz. In situ timing verification was performed with a dc xenon discharge lamp with an uncertainty less than 100 ns for a 38 {mu}s chopping period. Energy calibration was accomplished with a singly ionized lithium source in the range of 300-1500 eV, achieving an average energy uncertainty, {delta}E/E, of 0.11. The diagnostic has measured neutrals in the range of 20-80 eV from the IFRC and the corresponding energy distribution function has been obtained.

  19. Multi-strange baryon elliptic flow in Pb-Pb collisions at sqrt {s_{NN} } = 2.76 TeV measured with the ALICE detector

    NASA Astrophysics Data System (ADS)

    Yin, Zhongbao

    2012-12-01

    We present the results on elliptic flow with multi-strange baryons produced in Pb-Pb collisions at sqrt {s_{NN} } = 2.76 TeV. The analysis is performed with the ALICE detector at LHC. Multi-strange baryons are reconstructed via their decay topologies and the v 2 measurements are analyzed with the two-particle scalar product method. The p T differential v 2 values are compared to the viscous hydrodynamical (VISH2+1) model calculation and to the STAR measurements in Au-Au collisions at sqrt {s_{NN} } = 200 GeV. We found that the model describes ≡ and Ωv 2 measurements within uncertainties. The differential v 2 of ≡ and Ω is similar to the STAR measurements at 200 GeV in Au-Au collisions.

  20. Multi-strange baryon elliptic flow in Pb-Pb collisions at sqrt {s_{NN} } = 2.76 TeV measured with the ALICE detector

    NASA Astrophysics Data System (ADS)

    Yin, Zhongbao

    2012-12-01

    We present the results on elliptic flow with multi-strange baryons produced in Pb-Pb collisions at sqrt {s_{NN} } = 2.76 TeV. The analysis is performed with the ALICE detector at LHC. Multi-strange baryons are reconstructed via their decay topologies and the v 2 measurements are analyzed with the two-particle scalar product method. The p T differential v 2 values are compared to the viscous hydrodynamical (VISH2+1) model calculation and to the STAR measurements in Au-Au collisions at sqrt {s_{NN} } = 200 GeV. We found that the model describes ≡ and Ω v 2 measurements within uncertainties. The differential v 2 of ≡ and Ω is similar to the STAR measurements at 200 GeV in Au-Au collisions.

  1. Time-of-Flight Measurements of Single-Electron Wave Packets in Quantum Hall Edge States

    NASA Astrophysics Data System (ADS)

    Kataoka, M.; Johnson, N.; Emary, C.; See, P.; Griffiths, J. P.; Jones, G. A. C.; Farrer, I.; Ritchie, D. A.; Pepper, M.; Janssen, T. J. B. M.

    2016-03-01

    We report time-of-flight measurements on electrons traveling in quantum Hall edge states. Hot-electron wave packets are emitted one per cycle into edge states formed along a depleted sample boundary. The electron arrival time is detected by driving a detector barrier with a square wave that acts as a shutter. By adding an extra path using a deflection barrier, we measure a delay in the arrival time, from which the edge-state velocity v is deduced. We find that v follows 1 /B dependence, in good agreement with the E →×B → drift. The edge potential is estimated from the energy dependence of v using a harmonic approximation.

  2. An Improvement on Space Focusing Resolution in Two-Field Time-of-Flight Mass Spectrometers

    SciTech Connect

    Yildirim, M.; Aydin, R.; Akin, U.; Kilic, H. S.; Sise, O.; Ulu, M.; Dogan, M.

    2007-04-23

    Time-of-Flight Mass Spectrometer (TOFMS) is a sophisticated device for the mass selective analysis of a variety of samples. The main limitation on TOFMS technique is the obtainable resolution where the two main limiting factors are the initial space and energy spread of particles created in ionization region. Similar charged particles starting at different points will reach the detector at different times. So, this problem makes space focusing is very important subject. We have presented principles of two-fields TOFMS with second-order space focusing both using analytical methods and ray-tracing simulation. This work aims understanding of ion optical system clearly and gives hint of expectation for future developments.

  3. Video Guidance Sensor and Time-of-Flight Rangefinder

    NASA Technical Reports Server (NTRS)

    Bryan, Thomas; Howard, Richard; Bell, Joseph L.; Roe, Fred D.; Book, Michael L.

    2007-01-01

    A proposed video guidance sensor (VGS) would be based mostly on the hardware and software of a prior Advanced VGS (AVGS), with some additions to enable it to function as a time-of-flight rangefinder (in contradistinction to a triangulation or image-processing rangefinder). It would typically be used at distances of the order of 2 or 3 kilometers, where a typical target would appear in a video image as a single blob, making it possible to extract the direction to the target (but not the orientation of the target or the distance to the target) from a video image of light reflected from the target. As described in several previous NASA Tech Briefs articles, an AVGS system is an optoelectronic system that provides guidance for automated docking of two vehicles. In the original application, the two vehicles are spacecraft, but the basic principles of design and operation of the system are applicable to aircraft, robots, objects maneuvered by cranes, or other objects that may be required to be aligned and brought together automatically or under remote control. In a prior AVGS system of the type upon which the now-proposed VGS is largely based, the tracked vehicle is equipped with one or more passive targets that reflect light from one or more continuous-wave laser diode(s) on the tracking vehicle, a video camera on the tracking vehicle acquires images of the targets in the reflected laser light, the video images are digitized, and the image data are processed to obtain the direction to the target. The design concept of the proposed VGS does not call for any memory or processor hardware beyond that already present in the prior AVGS, but does call for some additional hardware and some additional software. It also calls for assignment of some additional tasks to two subsystems that are parts of the prior VGS: a field-programmable gate array (FPGA) that generates timing and control signals, and a digital signal processor (DSP) that processes the digitized video images. The

  4. An improved method for calibrating time-of-flight Laue single-crystal neutron diffractometers

    PubMed Central

    Bull, Craig L.; Johnson, Michael W.; Hamidov, Hayrullo; Komatsu, Kazuki; Guthrie, Malcolm; Gutmann, Matthias J.; Loveday, John S.; Nelmes, Richard J.

    2014-01-01

    A robust and comprehensive method for determining the orientation matrix of a single-crystal sample using the neutron Laue time-of-flight (TOF) technique is described. The new method enables the measurement of the unit-cell parameters with an uncertainty in the range 0.015–0.06%, depending upon the crystal symmetry and the number of reflections measured. The improved technique also facilitates the location and integration of weak reflections, which are often more difficult to discern amongst the increased background at higher energies. The technique uses a mathematical model of the relative positions of all the detector pixels of the instrument, together with a methodology that establishes a reproducible reference frame and a method for determining the parameters of the instrument detector model. Since all neutron TOF instruments require precise detector calibration for their effective use, it is possible that the method described here may be of use on other instruments where the detector calibration cannot be determined by other means. PMID:24904244

  5. A real time scintillating fiber Time of Flight spectrometer for LINAC photoproduced neutrons

    NASA Astrophysics Data System (ADS)

    Maspero, M.; Berra, A.; Conti, V.; Giannini, G.; Ostinelli, A.; Prest, M.; Vallazza, E.

    2015-03-01

    The use of high-energy (> 8 MeV) LINear ACcelerators (LINACs) for medical cancer treatments causes the photoproduction of secondary neutrons, whose unwanted dose to the patient has to be calculated. The characterization of the neutron spectra is necessary to allow the dosimetric evaluation of the neutron beam contamination. The neutron spectrum in a hospital environment is usually measured with integrating detectors such as bubble dosimeters, Thermo Luminescent Dosimeters (TLDs) or Bonner Spheres, which integrate the information over a time interval and an energy one. This paper presents the development of a neutron spectrometer based on the Time of Flight (ToF) technique in order to perform a real time characterization of the neutron contamination. The detector measures the neutron spectrum exploiting the fact that the LINAC beams are pulsed and arranged in bunches with a rate of 100-300 Hz depending on the beam type and energy. The detector consists of boron loaded scintillating fibers readout by a MultiAnode PhotoMultiplier Tube (MAPMT). A detailed description of the detector and the acquisition system together with the results in terms of ToF spectra and number of neutrons with a Varian Clinac iX are presented.

  6. Development of EndoTOFPET-US, a multi-modal endoscope for ultrasound and time of flight positron emission tomography

    NASA Astrophysics Data System (ADS)

    Pizzichemi, M.

    2014-02-01

    The EndoTOFPET-US project aims at delevoping a multi-modal imaging device that combines Ultrasound with Time-Of-Flight Positron Emission Tomography into an endoscopic imaging device. The goal is to obtain a coincidence time resolution of about 200 ps FWHM and sub-millimetric spatial resolution for the PET head, integrating the components in a very compact detector suitable for endoscopic use. The scanner will be exploited for the clinical test of new bio-markers especially targeted for prostate and pancreatic cancer as well as for diagnostic and surgical oncology. This paper focuses on the status of the Time-Of-Flight Positron Emission Tomograph under development for the EndoTOFPET-US project.

  7. A novel double-focusing time-of-flight mass spectrometer for absolute recoil ion cross sections measurements.

    PubMed

    Sigaud, L; de Jesus, V L B; Ferreira, Natalia; Montenegro, E C

    2016-08-01

    In this work, the inclusion of an Einzel-like lens inside the time-of-flight drift tube of a standard mass spectrometer coupled to a gas cell-to study ionization of atoms and molecules by electron impact-is described. Both this lens and a conical collimator are responsible for further focalization of the ions and charged molecular fragments inside the spectrometer, allowing a much better resolution at the time-of-flight spectra, leading to a separation of a single mass-to-charge unit up to 100 a.m.u. The procedure to obtain the overall absolute efficiency of the spectrometer and micro-channel plate detector is also discussed. PMID:27587105

  8. Design of a magnetic shielding system for the time of flight enhanced diagnostics neutron spectrometer at Experimental Advanced Superconducting Tokamak

    SciTech Connect

    Cui, Z. Q.; Chen, Z. J.; Xie, X. F.; Peng, X. Y.; Hu, Z. M.; Du, T. F.; Ge, L. J.; Zhang, X.; Yuan, X.; Fan, T. S.; Chen, J. X.; Li, X. Q. E-mail: guohuizhang@pku.edu.cn; Zhang, G. H. E-mail: guohuizhang@pku.edu.cn; Xia, Z. W.; Hu, L. Q.; Zhong, G. Q.; Lin, S. Y.; Wan, B. N.

    2014-11-15

    The novel neutron spectrometer TOFED (Time of Flight Enhanced Diagnostics), comprising 90 individual photomultiplier tubes coupled with 85 plastic scintillation detectors through light guides, has been constructed and installed at Experimental Advanced Superconducting Tokamak. A dedicated magnetic shielding system has been constructed for TOFED, and is designed to guarantee the normal operation of photomultiplier tubes in the stray magnetic field leaking from the tokamak device. Experimental measurements and numerical simulations carried out employing the finite element method are combined to optimize the design of the magnetic shielding system. The system allows detectors to work properly in an external magnetic field of 200 G.

  9. Design of a magnetic shielding system for the time of flight enhanced diagnostics neutron spectrometer at Experimental Advanced Superconducting Tokamak.

    PubMed

    Cui, Z Q; Chen, Z J; Xie, X F; Peng, X Y; Hu, Z M; Du, T F; Ge, L J; Zhang, X; Yuan, X; Xia, Z W; Hu, L Q; Zhong, G Q; Lin, S Y; Wan, B N; Fan, T S; Chen, J X; Li, X Q; Zhang, G H

    2014-11-01

    The novel neutron spectrometer TOFED (Time of Flight Enhanced Diagnostics), comprising 90 individual photomultiplier tubes coupled with 85 plastic scintillation detectors through light guides, has been constructed and installed at Experimental Advanced Superconducting Tokamak. A dedicated magnetic shielding system has been constructed for TOFED, and is designed to guarantee the normal operation of photomultiplier tubes in the stray magnetic field leaking from the tokamak device. Experimental measurements and numerical simulations carried out employing the finite element method are combined to optimize the design of the magnetic shielding system. The system allows detectors to work properly in an external magnetic field of 200 G. PMID:25430242

  10. Measurement of DT and DD components in neutron spectrum with a double-crystal time-of-flight spectrometer

    NASA Astrophysics Data System (ADS)

    Okada, K.; Kondo, K.; Ochiai, K.; Sato, S.; Nishitani, T.; Konno, C.; Okamoto, A.; Kitajima, S.; Sasao, M.

    2008-03-01

    To investigate the deuteron and triton density ratio in core plasmas, a new methodology with measurement of tritium (DT) and deuterium (DD) neutron count rate ratio using a double-crystal time-of-flight (TOF) spectrometer is proposed. Multi-discriminator electronic circuits for the first and second detectors are used in addition to the TOF technique. The optimum arrangement of the detectors and discrimination window were examined considering the relations between the geometrical arrangement and deposited energy using a Monte Carlo Code, PHITS (Particle and Heavy Ion Transport Code System). An experiment to verify the calculations was performed using DD neutrons from an accelerator.

  11. Design of a magnetic shielding system for the time of flight enhanced diagnostics neutron spectrometer at Experimental Advanced Superconducting Tokamak

    NASA Astrophysics Data System (ADS)

    Cui, Z. Q.; Chen, Z. J.; Xie, X. F.; Peng, X. Y.; Hu, Z. M.; Du, T. F.; Ge, L. J.; Zhang, X.; Yuan, X.; Xia, Z. W.; Hu, L. Q.; Zhong, G. Q.; Lin, S. Y.; Wan, B. N.; Fan, T. S.; Chen, J. X.; Li, X. Q.; Zhang, G. H.

    2014-11-01

    The novel neutron spectrometer TOFED (Time of Flight Enhanced Diagnostics), comprising 90 individual photomultiplier tubes coupled with 85 plastic scintillation detectors through light guides, has been constructed and installed at Experimental Advanced Superconducting Tokamak. A dedicated magnetic shielding system has been constructed for TOFED, and is designed to guarantee the normal operation of photomultiplier tubes in the stray magnetic field leaking from the tokamak device. Experimental measurements and numerical simulations carried out employing the finite element method are combined to optimize the design of the magnetic shielding system. The system allows detectors to work properly in an external magnetic field of 200 G.

  12. Time-of-flight observation of electron swarm in methane

    NASA Astrophysics Data System (ADS)

    Hasegawa, H.; Date, H.; Yoshida, K.; Shimozuma, M.

    2009-06-01

    This paper reports on the evolution of an isolated electron swarm, which is experimentally observed as spatial distributions at every moment. This observation is assumed to directly correspond to the conventional time-of-flight theory. We have measured the spatial distribution of electrons using a double-shutter technique in the drift tube, where a shutter electrode to collect electrons can be slid along the field (E /N) direction in order to capture a relative electron number at a certain range of location. As a typical parameter defined by this spatial distribution, the center-of-mass drift velocity (Wr) is determined for methane gas. The result is compared with the mean-arrival-time drift velocity (Wm) defined from the arriving electron number at fixed positions. We have also performed a theoretical analysis in which a Fourier transformed Boltzmann equation is solved to deduce both of the drift velocities from a dispersion relationship. The difference between Wr and Wm at high E /Ns (above 200 Td) is clearly ascertained in the experimental and theoretical investigations, which is attributable to the occurrence of ionization events.

  13. Analysis of Trap Distribution Using Time-of-Flight Spectroscopy

    NASA Astrophysics Data System (ADS)

    Ohno, Akira; Hanna, Jun-ichi; Dunlap, David H.

    2008-02-01

    A new analytical method for determining trap distribution from a transient photocurrent in time-of-flight (TOF) measurements has been proposed in the context of convection diffusion equation with multiple-trapping and detrapping processes. The method does not need, in principle, data on temperature dependence and any initial assumption about the form of trap distribution. A trap distribution is directly extracted from time profiles of transient photocurrents on assuming the Einstein relation between mobility and diffusion constant. To demonstrate the validity of the method, we first applied photocurrents that were prepared in advance by random walk simulation for some typical trap distributions assumed. Then, we attempt to determine a trap distribution for a particular mesophase of a liquid crystal of phenylnaphthalene derivative, for which the temperature dependence of carrier transport properties is hardly available. Indeed, we have obtained an extrinsic shallow trap distribution at about 200 meV in depth together with a tail-shaped Gaussian-type density-of-states distribution. Thus, we conclude that the method may be a powerful tool to analyze a trap distribution for a system that exhibits temperature-sensitive conformational changes and/or whose carrier transport properties are not available as a function of temperature.

  14. Laser Time-of-Flight Mass Spectrometry for Space

    NASA Technical Reports Server (NTRS)

    Brinckerhoff, W. B.; Managadze, G. G.; McEntire, R. W.; Cheng, A. F.; Green, W. J.

    2000-01-01

    A miniature reflection time-of-flight mass spectrometer for in situ planetary surface analysis is described. The laser ablation mass spectrometer (LAMS) measures the regolith's elemental and isotopic composition without high-voltage source extraction or sample preparation. The compact size (< 2 x 10(exp 3) cubic cm) and low mass (approximately 2 kg) of LAMS, due to its fully coaxial design and two-stage reflectron, fall within the strict resource limitations of landed science missions to solar system bodies. A short-pulse laser focused to a spot with a diameter approximately 30-50 micrometers is used to obtain microscopic surface samples. Assisted by a microimager, LAMS can interactively select and analyze a range of compositional regions (with lateral motion) and with repeated pulses can access unweathered, subsurface materials. The mass resolution is calibrated to distinguish isotopic peaks at unit masses, and detection limits are on resolved to a few ppm. The design and calibration method of a prototype LAMS device is described, which include the development of preliminary relative sensitivity coefficients for major element bulk abundance measurements.

  15. Time-of-Flight Mass Measurements of Exotic Nuclei

    SciTech Connect

    Matos, M.; Famiano, M.; Gade, A.; George, S.; Lynch, W. G.; Rogers, A.; Stolz, A.; Wallace, M.; Yurkon, J.

    2012-01-01

    Atomic masses play an important role in nuclear physics and astrophysics. The need of experimental mass values for unstable nuclides has triggered the development of a wide range of mass measurement techniques, with devices installed at many laboratories around the world. We have implemented a time-of-flight magnetic-rigidity (TOF-B ) technique at the National Superconducting Cyclotron Laboratory (NSCL) that includes a position measurement for magnetic rigidity corrections and uses the A1900 separator and the S800 spectrograph. We performed a successful first experiment measuring masses of neutron-rich isotopes in the region of Z 20 30, important for calculations of processes occurring in the crust of accreting neutron stars. The masses of 16 nuclei were determined, for 61V, 63Cr, 66Mn, and 74Ni for the first time, with atomic mass excesses of 30.510(890) MeV, 35.280(650) MeV, 36.900(790) MeV, and 49.210(990) MeV, respectively. The mass resolution achieved was 1.8 10 4.

  16. The high-resolution time-of-flight spectrometer TOFTOF

    NASA Astrophysics Data System (ADS)

    Unruh, Tobias; Neuhaus, Jürgen; Petry, Winfried

    2007-10-01

    The TOFTOF spectrometer is a multi-disc chopper time-of-flight spectrometer for cold neutrons at the research neutron source Heinz Maier-Leibnitz (FRM II). After five reactor cycles of routine operation the characteristics of the instrument are reported in this article. The spectrometer features an excellent signal to background ratio due to its remote position in the neutron guide hall, an elaborated shielding concept and an s-shaped curved primary neutron guide which acts i.a. as a neutron velocity filter. The spectrometer is fed with neutrons from the undermoderated cold neutron source of the FRM II leading to a total neutron flux of ˜1010n/cm2/s in the continuous white beam at the sample position distributed over a continuous and particularly broad wavelength spectrum. A high energy resolution is achieved by the use of high speed chopper discs made of carbon-fiber-reinforced plastic. In the combination of intensity, resolution and signal to background ratio the spectrometer offers new scientific prospects in the fields of inelastic and quasielastic neutron scattering.

  17. Fast Analysis of Potential Scintillators Using Ion Time Of Flight

    NASA Astrophysics Data System (ADS)

    Milbrath, Brian; Zhang, Yanwen

    2008-05-01

    The development of scintillators for radiation applications such as national security, medical imaging, and experimental nuclear/particle physics has historically been rather slow, principally due to the developmental time necessary for large crystal growth. Scintillator crystals must achieve dimensions of a few mm before important characterizations, such as gamma ray energy resolution, can be performed. In order to facilitate accelerated discovery, we developed a time of flight (TOF) telescope for use on an ion beam. This allows individual determination of the ion energies prior to impinging the crystal, which may be a very thin prototype material. With such a technique, the scintillator performance in terms of energy resolution, light yield, decay time, and spectrum, can be determined quickly over a broad energy range. Though the analysis is performed using ions rather than the gamma-rays whose detection is the ultimate aim of the materials investigated, we have found useful correlations between the ion and gamma responses of the materials we have investigated (CaF2:Eu, YAP:Ce, BGO, CsI:Tl, and plastic scintillator). The technique appears to be able to rapidly determine whether a scintillator material has promise for further development.

  18. The Cherenkov radiator system of the high momentum particle identification detector of the ALICE experiment at CERN-LHC

    NASA Astrophysics Data System (ADS)

    Pastore, C.; Sgura, I.; De Cataldo, G.; Franco, A.; Fratino, U.

    2011-05-01

    The aim of this paper is to present the design, the implementation and the operational modes of the Liquid Circulation System (LCS) built to circulate, purify and monitor the liquid perfluorohexane (C 6F 14) in the ALICE HMPID. The HMPID RICH uses C 6F 14 as Cherenkov radiator medium circulating in 21 quartz trays. LCS features a pressure-regulated closed circuit, ensuring the C 6F 14 highest transparency to ultraviolet light. Intrinsically safe working conditions are obtained, thanks to a novel liquid distribution "cascade" system. Moreover the system is protected against anomalous working conditions by a dedicated Control System, which operates it in both automatic and manual mode, locally and remotely, safeguarding the quartz radiator vessels.

  19. Development of the FoCal-E PAD detector and its electronics for the ALICE experiment at the LHC

    NASA Astrophysics Data System (ADS)

    Inaba, Motoi; Chujo, Tatsuya; Hirano, Masahiro

    2016-07-01

    In order to study the initial state of high-energy heavy-ion collisions, a forward calorimeter as an upgrade to the ALICE experiment is in the planning stage. The first beam test of the forward electro-magnetic calorimeter (FoCal-E) prototype was carried out in 2014 at the CERN PS and SPS accelerators. With the aim of reading out a signal from the low-granularity silicon pad sensors of FoCal-E, electronic circuits such as a temperature monitor, a trigger-signal converting-circuit, a trigger-signal processor, an independent regulated power circuit and an isolated high-voltage generator were developed. The electric noise problem was solved by means of both the power circuit and the high-voltage generator, and the signal was successfully read out.

  20. Development of position-sensitive time-of-flight spectrometer for fission fragment research

    DOE PAGESBeta

    Arnold, C. W.; Tovesson, F.; Meierbachtol, K.; Bredeweg, T.; Jandel, M.; Jorgenson, H. J.; Laptev, A.; Rusev, G.; Shields, D. W.; White, M.; et al

    2014-07-09

    A position-sensitive, high-resolution time-of-flight detector for fission fragments has been developed. The SPectrometer for Ion DEtermination in fission Research (SPIDER) is a 2E–2v spectrometer designed to measure the mass of light fission fragments to a single mass unit. The time pick-off detector pairs to be used in SPIDER have been tested with α-particles from 229Th and its decay chain and α-particles and spontaneous fission fragments from 252Cf. Each detector module is comprised of thin electron conversion foil, electrostatic mirror, microchannel plates, and delay-line anodes. Particle trajectories on the order of 700 mm are determined accurately to within 0.7 mm. Flightmore » times were measured with 250 ps resolution FWHM. Computed particle velocities are accurate to within 0.06 mm/ns corresponding to a precision of 0.5%. As a result, an ionization chamber capable of 400 keV energy resolution coupled with the velocity measurements described here will pave the way for modestly efficient measurements of light fission fragments with unit mass resolution.« less

  1. Development of position-sensitive time-of-flight spectrometer for fission fragment research

    SciTech Connect

    Arnold, C. W.; Tovesson, F.; Meierbachtol, K.; Bredeweg, T.; Jandel, M.; Jorgenson, H. J.; Laptev, A.; Rusev, G.; Shields, D. W.; White, M.; Blakeley, R. E.; Mader, D. M.; Hecht, A. A.

    2014-07-09

    A position-sensitive, high-resolution time-of-flight detector for fission fragments has been developed. The SPectrometer for Ion DEtermination in fission Research (SPIDER) is a 2E–2v spectrometer designed to measure the mass of light fission fragments to a single mass unit. The time pick-off detector pairs to be used in SPIDER have been tested with α-particles from 229Th and its decay chain and α-particles and spontaneous fission fragments from 252Cf. Each detector module is comprised of thin electron conversion foil, electrostatic mirror, microchannel plates, and delay-line anodes. Particle trajectories on the order of 700 mm are determined accurately to within 0.7 mm. Flight times were measured with 250 ps resolution FWHM. Computed particle velocities are accurate to within 0.06 mm/ns corresponding to a precision of 0.5%. As a result, an ionization chamber capable of 400 keV energy resolution coupled with the velocity measurements described here will pave the way for modestly efficient measurements of light fission fragments with unit mass resolution.

  2. Measurement of prompt fission neutron spectrum using a gamma tag double time-of-flight setup

    NASA Astrophysics Data System (ADS)

    Blain, Ezekiel

    Current uncertainties in the prompt fission neutron spectrum have a significant effect of up to 4% on keff for reactor criticality and safety calculations. Therefore, a method was developed at RPI to improve the accuracy of the measurement of the prompt fission neutron spectrum. This method involves using an array of BaF2 gamma detectors to tag that a fission event has occurred, and a double time-of-flight setup to obtain the prompt fission neutron spectrum as a function of incident neutron energy. The gamma tagging method improves upon conventional fission chambers by allowing for much larger sample sizes to be utilized while not suffering from effects of discriminator level on the shape of the prompt fission neutron spectrum. A coincidence requirement on an array of 4 BaF2 gamma detectors is used to determine the timing of the fission event. Furthermore, a method is under development for the use of thin plastic scintillators for measurement of the prompt fission neutron spectrum with low energies. Measurements with spontaneous fission of . {252} Cf show good agreement with previous datasets and current evaluations as well as providing accurate data down to 50 keV with the plastic scintillator detector. Preliminary incident neutron beam analysis was performed with 238U and shows good agreement with the current evaluations demonstrating the feasibility of the gamma tagging method for in beam prompt fission neutron spectrum measurements of various isotopes.

  3. Dynamically Multiplexed Ion Mobility Time-of-Flight Mass Spectrometry

    PubMed Central

    Belov, Mikhail E.; Clowers, Brian H.; Prior, David C.; Danielson, William F.; Liyu, Andrei V.; Petritis, Brianne O.; Smith, Richard D.

    2010-01-01

    Ion Mobility Spectrometry–Time-of-Flight Mass Spectrometry (IMS-TOFMS) has been increasingly used in analysis of complex biological samples. A major challenge is to transform IMS-TOFMS to a high-sensitivity high-throughput platform for e.g. proteomics applications. In this work, we have developed and integrated three advanced technologies, including efficient ion accumulation in the ion funnel trap prior to IMS separation, multiplexing (MP) of ion packet introduction into the IMS drift tube and signal detection with an analog-to-digital converter (ADC), into the IMS-TOFMS system for the high-throughput analysis of highly complex proteolytic digests of e.g. blood plasma. To better address variable sample complexity, we have developed and rigorously evaluated a novel dynamic MP approach that ensures correlation of the analyzer performance with an ion source function, and provides the improved dynamic range and sensitivity throughout the experiment. The MP IMS-TOF MS instrument has been shown to reliably detect peptides at a concentration of 1 nM in the presence of highly complex matrix, as well as to provide a three orders of magnitude dynamic range and a mass measurement accuracy of better than 5 ppm. When matched against human blood plasma database, the detected IMS-TOF features were found to yield ~ 700 unique peptide identifications at a false discovery rate (FDR) of ~ 7.5 %. Accounting for IMS information gave rise to a projected FDR of ~ 4 %. Signal reproducibility was found to be greater than 80 %, while the variations in the number of unique peptide identifications were < 15 %. A single sample analysis was completed in 15 min that constitutes almost an order of magnitude improvement compared to a more conventional LC-MS approach. PMID:18582088

  4. Sensors for Using Times of Flight to Measure Flow Velocities

    NASA Technical Reports Server (NTRS)

    Fralick, Gutave; Wrbanek, John D.; Hwang, Danny; Turso, James

    2006-01-01

    Thin-film sensors for measuring flow velocities in terms of times of flight are undergoing development. These sensors are very small and can be mounted flush with surfaces of airfoils, ducts, and other objects along which one might need to measure flows. Alternatively or in addition, these sensors can be mounted on small struts protruding from such surfaces for acquiring velocity measurements at various distances from the surfaces for the purpose of obtaining boundary-layer flow-velocity profiles. These sensors are related to, but not the same as, hot-wire anemometers. Each sensor includes a thin-film, electrically conductive loop, along which an electric current is made to flow to heat the loop to a temperature above that of the surrounding fluid. Instantaneous voltage fluctuations in segments of the loop are measured by means of electrical taps placed at intervals along the loop. These voltage fluctuations are caused by local fluctuations in electrical resistance that are, in turn, caused by local temperature fluctuations that are, in turn, caused by fluctuations in flow-induced cooling and, hence, in flow velocity. The differential voltage as a function of time, measured at each pair of taps, is subjected to cross-correlation processing with the corresponding quantities measured at other pairs of taps at different locations on the loop. The cross-correlations yield the times taken by elements of fluid to travel between the pairs of taps. Then the component of velocity along the line between any two pairs of taps is calculated simply as the distance between the pairs of taps divided by the travel time. Unlike in the case of hot-wire anemometers, there is no need to obtain calibration data on voltage fluctuations versus velocity fluctuations because, at least in principle, the correlation times are independent of the calibration data.

  5. LVGEMS Time-of-Flight Mass Spectrometry on Satellites

    NASA Technical Reports Server (NTRS)

    Herrero, Federico

    2013-01-01

    NASA fs investigations of the upper atmosphere and ionosphere require measurements of composition of the neutral air and ions. NASA is able to undertake these observations, but the instruments currently in use have their limitations. NASA has extended the scope of its research in the atmosphere and now requires more measurements covering more of the atmosphere. Out of this need, NASA developed multipoint measurements using miniaturized satellites, also called nanosatellites (e.g., CubeSats), that require a new generation of spectrometers that can fit into a 4 4 in. (.10 10 cm) cross-section in the upgraded satellites. Overall, the new mass spectrometer required for the new depth of atmospheric research must fulfill a new level of low-voltage/low-power requirements, smaller size, and less risk of magnetic contamination. The Low-Voltage Gated Electrostatic Mass Spectrometer (LVGEMS) was developed to fulfill these requirements. The LVGEMS offers a new spectrometer that eliminates magnetic field issues associated with magnetic sector mass spectrometers, reduces power, and is about 1/10 the size of previous instruments. LVGEMS employs the time of flight (TOF) technique in the GEMS mass spectrometer previously developed. However, like any TOF mass spectrometer, GEMS requires a rectangular waveform of large voltage amplitude, exceeding 100 V -- that means that the voltage applied to one of the GEMS electrodes has to change from 0 to 100 V in a time of only a few nanoseconds. Such electronic speed requires more power than can be provided in a CubeSat. In the LVGEMS, the amplitude of the rectangular waveform is reduced to about 1 V, compatible with digital electronics supplies and requiring little power.

  6. Dynamically multiplexed ion mobility time-of-flight mass spectrometry.

    PubMed

    Belov, Mikhail E; Clowers, Brian H; Prior, David C; Danielson, William F; Liyu, Andrei V; Petritis, Brianne O; Smith, Richard D

    2008-08-01

    Ion mobility spectrometry-time-of-flight mass spectrometry (IMS-TOFMS) has been increasingly used in analysis of complex biological samples. A major challenge is to transform IMS-TOFMS to a high-sensitivity, high-throughput platform, for example, for proteomics applications. In this work, we have developed and integrated three advanced technologies, including efficient ion accumulation in an ion funnel trap prior to IMS separation, multiplexing (MP) of ion packet introduction into the IMS drift tube, and signal detection with an analog-to-digital converter, into the IMS-TOFMS system for the high-throughput analysis of highly complex proteolytic digests of, for example, blood plasma. To better address variable sample complexity, we have developed and rigorously evaluated a novel dynamic MP approach that ensures correlation of the analyzer performance with an ion source function and provides the improved dynamic range and sensitivity throughout the experiment. The MP IMS-TOFMS instrument has been shown to reliably detect peptides at a concentration of 1 nM in the presence of a highly complex matrix, as well as to provide a 3 orders of magnitude dynamic range and a mass measurement accuracy of better than 5 ppm. When matched against human blood plasma database, the detected IMS-TOF features were found to yield approximately 700 unique peptide identifications at a false discovery rate (FDR) of approximately 7.5%. Accounting for IMS information gave rise to a projected FDR of approximately 4%. Signal reproducibility was found to be greater than 80%, while the variations in the number of unique peptide identifications were <15%. A single sample analysis was completed in 15 min that constitutes almost 1 order of magnitude improvement compared to a more conventional LC-MS approach. PMID:18582088

  7. Dynamically Multiplexed Ion Mobility Time-of-Flight Mass Spectrometry

    SciTech Connect

    Belov, Mikhail E.; Clowers, Brian H.; Prior, David C.; Danielson, William F.; Liyu, Andrei V.; Petritis, Brianne O.; Smith, Richard D.

    2008-08-01

    Ion Mobility Spectrometry–Time-of-Flight Mass Spectrometry (IMS-TOFMS) has been increasingly used in analysis of complex biological samples. A major challenge is to transform IMS-TOFMS to a high-sensitivity high-throughput platform for e.g. proteomics applications. In this work, we have developed and integrated three advanced technologies, enabling (1) efficient ion accumulation in the ion funnel trap prior to IMS separation, (2) multiplexing (MP) of ion packet introduction into the IMS drift tube and (3) signal detection with an analog-to-digital converter (ADC), into the IMS-TOFMS system for the high-throughput analysis of highly complex proteolytic digests of e.g. blood plasma. To better address variable sample complexity, we have additionally developed and rigorously evaluated a new dynamic MP approach that ensures correlation of the analyzer performance with an ion source function, and provides the improved dynamic range and sensitivity. The MP IMS-TOF MS instrument has been shown to reliably detect peptides at a concentration of 1 nM in a highly complex matrix, as well as to provide a four orders of magnitude dynamic range and a mass measurement accuracy of better than 5 ppm. When matched against human blood plasma database, the detected IMS-TOF features yielded ~ 700 unique peptide identifications at a false discovery rate (FDR) of ~ 7.5 %. Accounting for IMS information gave rise to a projected FDR of ~ 4 %. Signal reproducibility was found to be greater than 80 %, while the variations in the number of unique peptide identifications were < 15 %. A single sample analysis was completed in 15 min, corresponding to approximately an order of magnitude improvement compared to a more conventional LC-MS approach.

  8. Development of grazing incidence devices for space-borne time of flight mass spectrometry

    NASA Astrophysics Data System (ADS)

    Cadu, A.; Devoto, P.; Louarn, P.; Sauvaud, J.-A.

    2012-04-01

    Time of flight mass spectrometer is widely used to study space plasmas in planetary and solar missions. This space-borne instrument selects ions in function of their energy through an electrostatic analyzer. Particles are then post-accelerated to energies in the range of 20 keV to cross a carbon foil. At the foil exit, electrons are emitted and separated from ion beam in the time of flight section. A first detector (a Micro-Channel Plate or MCP) emits a start signal at electron arrival and a second one emits a stop signal at incident ion end of path. The time difference gives the speed of the particle and its mass can be calculated, knowing its initial energy. However, current instruments suffer from strong limitations. The post acceleration needs very high voltage power supplies which are heavy, have a high power consumption and imply technical constraints for the development. A typical instrument weighs from 5 to 6 kg, includes a 20 kV power supply, consumes a least 5 W and encounters corona effect and electrical breakdown problems. Moreover, despite the particle high energy range, scattering and straggling phenomena in the carbon foil significantly reduce the instrument overall resolution. Some methods, such as electrostatic focus lenses or reflectrons, really improve mass separation but global system efficiency remains very low because of the charge state dependence of such devices. The main purpose of our work is to replace carbon foil by grazing incidence MCP's - also known as MPO's, for Micro Pore Optics - for electron emission. Thus, incident particles would back-scatter onto the channel inner surface with an angle of a few degrees. With this solution, we can decrease dispersion sources and lower the power supplies to post accelerate ions. The result would be a lighter and simpler instrument with a substantial resolution improvement. We have first simulated MPO's behavior with TRIM and MARLOWE Monte-Carlo codes. Energy scattering and output angle computed

  9. High-speed digitization readout of silicon photomultipliers for time of flight positron emission tomography

    SciTech Connect

    Ronzhin, A.; Los, S.; Martens, M.; Ramberg, E.; Kim, H.; Chen, C.; Kao, C.; Niessen, K.; Zatserklyaniy, A.; Mazzillo, M.; Carbone, B.; /SGS Thomson, Catania

    2011-02-01

    We report on work to develop a system with about 100 picoseconds (ps) time resolution for time of flight positron emission tomography [TOF-PET]. The chosen photo detectors for the study were Silicon Photomultipliers (SiPM's). This study was based on extensive experience in studying timing properties of SiPM's. The readout of these devices used the commercial high speed digitizer DRS4. We applied different algorithms to get the best time resolution of 155 ps Guassian (sigma) for a LYSO crystal coupled to a SiPM. We consider the work as a first step in building a prototype TOF-PET module. The field of positron-emission-tomography (PET) has been rapidly developing. But there are significant limitations in how well current PET scanners can reconstruct images, related to how fast data can be acquired, how much volume they can image, and the spatial and temporal resolution of the generated photons. Typical modern scanners now include multiple rings of detectors, which can image a large volume of the patient. In this type of scanner, one can treat each ring as a separate detector and require coincidences only within the ring, or treat the entire region viewed by the scanner as a single 3 dimensional volume. This 3d technique has significantly better sensitivity since more photon pair trajectories are accepted. However, the scattering of photons within the volume of the patient, and the effect of random coincidences limits the technique. The advent of sub-nanosecond timing resolution detectors means that there is potentially much better rejection of scattered photon events and random coincidence events in the 3D technique. In addition, if the timing is good enough, then the origin of photons pairs can be determined better, resulting in improved spatial resolution - so called 'Time-of-Flight' PET, or TOF-PET. Currently a lot of activity has occurred in applications of SiPMs for TOF-PET. This is due to the devices very good time resolution, low profile, lack of high voltage

  10. Pulse processing routines for neutron time-of-flight data

    NASA Astrophysics Data System (ADS)

    Žugec, P.; Weiß, C.; Guerrero, C.; Gunsing, F.; Vlachoudis, V.; Sabate-Gilarte, M.; Stamatopoulos, A.; Wright, T.; Lerendegui-Marco, J.; Mingrone, F.; Ryan, J. A.; Warren, S. G.; Tsinganis, A.; Barbagallo, M.

    2016-03-01

    A pulse shape analysis framework is described, which was developed for n_TOF-Phase3, the third phase in the operation of the n_TOF facility at CERN. The most notable feature of this new framework is the adoption of generic pulse shape analysis routines, characterized by a minimal number of explicit assumptions about the nature of pulses. The aim of these routines is to be applicable to a wide variety of detectors, thus facilitating the introduction of the new detectors or types of detectors into the analysis framework. The operational details of the routines are suited to the specific requirements of particular detectors by adjusting the set of external input parameters. Pulse recognition, baseline calculation and the pulse shape fitting procedure are described. Special emphasis is put on their computational efficiency, since the most basic implementations of these conceptually simple methods are often computationally inefficient.

  11. Sensitivity estimation in time-of-flight list-mode positron emission tomography

    SciTech Connect

    Herraiz, J. L.; Sitek, A.

    2015-11-15

    Purpose: An accurate quantification of the images in positron emission tomography (PET) requires knowing the actual sensitivity at each voxel, which represents the probability that a positron emitted in that voxel is finally detected as a coincidence of two gamma rays in a pair of detectors in the PET scanner. This sensitivity depends on the characteristics of the acquisition, as it is affected by the attenuation of the annihilation gamma rays in the body, and possible variations of the sensitivity of the scanner detectors. In this work, the authors propose a new approach to handle time-of-flight (TOF) list-mode PET data, which allows performing either or both, a self-attenuation correction, and self-normalization correction based on emission data only. Methods: The authors derive the theory using a fully Bayesian statistical model of complete data. The authors perform an initial evaluation of algorithms derived from that theory and proposed in this work using numerical 2D list-mode simulations with different TOF resolutions and total number of detected coincidences. Effects of randoms and scatter are not simulated. Results: The authors found that proposed algorithms successfully correct for unknown attenuation and scanner normalization for simulated 2D list-mode TOF-PET data. Conclusions: A new method is presented that can be used for corrections for attenuation and normalization (sensitivity) using TOF list-mode data.

  12. The 27.3 meter neutron time-of-flight system for the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Grim, G. P.; Morgan, G. L.; Aragonez, R.; Archuleta, T. N.; Bower, D. E.; Danly, C. R.; Drury, O. B.; Dzenitis, J. M.; Fatherley, V. E.; Felker, B.; Fittinghoff, D. N.; Guler, N.; Merrill, F. E.; Oertel, J. A.; Wilde, C. H.; Wilke, M. D.

    2013-09-01

    One of the scientific goals of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory, Livermore CA, is to obtain thermonuclear ignition by compressing 2.2 mm diameter capsules filed with deuterium and tritium to densities approaching 1000 g/cm3 and temperatures in excess of 4 keV. Thefusion reaction d + t --> n + a results in a 14.03 MeV neutron providing a source of diagnostic particles to characterize the implosion. The spectrum of neutrons emanating from the assembly may be used to infer the fusion yield, plasma ion temperature, and fuel areal density, all key diagnostic quantities of implosion quality. The neutron time-of-flight (nToF) system co-located along the Neutron Imaging System line-of-site, (NIToF), is a set of 4 scintillation detectors located approximately 27.3 m from the implosion source. Neutron spectral information is inferred using arrival time at the detector. The NIToF system is described below, including the hardware elements, calibration data, analysis methods, and an example of its basic performance characteristics.

  13. Time-of-Flight Measurements of Vortices Emitted from Quantum Turbulence in Superfluid 4He

    NASA Astrophysics Data System (ADS)

    Kubo, H.; Nago, Y.; Nishijima, A.; Obara, K.; Yano, H.; Ishikawa, O.; Hata, T.

    2013-06-01

    An oscillating obstacle generates quantum turbulence in superfluids, when vortices remained attached to obstacle surfaces or vortex rings collided with it during oscillation. Turbulence provides a source of vortices; however, the characteristics of these vortices are not clear. In the present work, we report the flight of vortices emitted from quantum turbulence in superfluid 4He at low temperatures, using vibrating wires as a generator and a detector of vortices. A vortex-free vibrating wire can detect only the first colliding vortex ring, though it will be refreshed after low vibration and be able to detect a vortex ring again. By measuring a period from the start of turbulence generation to the vortex detection repeatedly, we find an exponential distribution of time-of-flights with a non-detection period t 0 and a mean detection period t 1, suggesting a Poisson process. Both periods t 0 and t 1 increase with increasing distance between a generator and a detector. A vortex flight velocity estimated from period t 0 suggests that the sizes of the emitted vortex rings distribute to a range smaller than a generator thickness or a generator vibration amplitude. Vortices are emitted radially from a turbulence region, at least in the direction of oscillator vibration.

  14. Indigenous design and development of multiPSD array for time of flight neutron spectrometer

    NASA Astrophysics Data System (ADS)

    Desai, Shraddha S.; Devan, Shylaja; Das, Amrita; Patkar, S. M.; Rao, Mala N.

    2016-05-01

    Time of Flight neutron Spectrometer for inelastic neutron scattering studies is being commissioned at Dhruva reactor. Neutron pulse tagging is carried out using the Fermi chopper. Scattered neutrons at maximum possible scattered solid angle are needed to be detected along with the time information at detector. Precise and efficient detection system is essential for measurement of spatial and temporal distribution. Detection area is optimized to cover an angle of 70° in horizontal direction and 23° in vertical direction. Position sensitive detectors (PSDs) are designed with judicial use of precious 3He gas and a few PSDs with BF3 gas as suitable alternative for 3He gas. An array of vertically arranged 1 m long, 50 PSDs, covers the arc length of 2.5 m and detection area 2.5 m2. The design of the BF3 PSDs is supported by investigations on the gas purity, fill gas pressure, drift region, drift field and neutron absorption in cathode wall. Design details and performance of the PSDs are presented in the paper.

  15. SYNCHROTRON RADIATION, FREE ELECTRON LASER, APPLICATION OF NUCLEAR TECHNOLOGY, ETC. Physical design of positronium time of flight spectroscopy apparatus

    NASA Astrophysics Data System (ADS)

    Jiang, Xiao-Pan; Zhang, Zi-Liang; Qin, Xiu-Bo; Yu, Run-Sheng; Wang, Bao-Yi

    2010-12-01

    Positronium time of flight spectroscopy (Ps-TOF) is an effective technique for porous material research. It has advantages over other techniques for analyzing the porosity and pore tortuosity of materials. This paper describes a design for Ps-TOF apparatus based on the Beijing intense slow positron beam, supplying a new material characterization technique. In order to improve the time resolution and increase the count rate of the apparatus, the detector system is optimized. For 3 eV o-Ps, the time broadening is 7.66 ns and the count rate is 3 cps after correction.

  16. Design of the radiation shielding for the time of flight enhanced diagnostics neutron spectrometer at Experimental Advanced Superconducting Tokamak

    SciTech Connect

    Du, T. F.; Chen, Z. J.; Peng, X. Y.; Yuan, X.; Zhang, X.; Hu, Z. M.; Cui, Z. Q.; Xie, X. F.; Ge, L. J.; Li, X. Q.; Zhang, G. H.; Chen, J. X.; Fan, T. S.; Gorini, G.; Nocente, M.; Tardocchi, M.; Hu, L. Q.; Zhong, G. Q.; Lin, S. Y.; Wan, B. N.

    2014-11-15

    A radiation shielding has been designed to reduce scattered neutrons and background gamma-rays for the new double-ring Time Of Flight Enhanced Diagnostics (TOFED). The shielding was designed based on simulation with the Monte Carlo code MCNP5. Dedicated model of the EAST tokamak has been developed together with the emission neutron source profile and spectrum; the latter were simulated with the Nubeam and GENESIS codes. Significant reduction of background radiation at the detector can be achieved and this satisfies the requirement of TOFED. The intensities of the scattered and direct neutrons in the line of sight of the TOFED neutron spectrometer at EAST are studied for future data interpretation.

  17. High-performance electronics for time-of-flight PET systems.

    PubMed

    Choong, W-S; Peng, Q; Vu, C Q; Turko, B T; Moses, W W

    2013-01-01

    We have designed and built a high-performance readout electronics system for time-of-flight positron emission tomography (TOF PET) cameras. The electronics architecture is based on the electronics for a commercial whole-body PET camera (Siemens/CPS Cardinal electronics), modified to improve the timing performance. The fundamental contributions in the electronics that can limit the timing resolution include the constant fraction discriminator (CFD), which converts the analog electrical signal from the photo-detector to a digital signal whose leading edge is time-correlated with the input signal, and the time-to-digital converter (TDC), which provides a time stamp for the CFD output. Coincident events are identified by digitally comparing the values of the time stamps. In the Cardinal electronics, the front-end processing electronics are performed by an Analog subsection board, which has two application-specific integrated circuits (ASICs), each servicing a PET block detector module. The ASIC has a built-in CFD and TDC. We found that a significant degradation in the timing resolution comes from the ASIC's CFD and TDC. Therefore, we have designed and built an improved Analog subsection board that replaces the ASIC's CFD and TDC with a high-performance CFD (made with discrete components) and TDC (using the CERN high-performance TDC ASIC). The improved Analog subsection board is used in a custom single-ring LSO-based TOF PET camera. The electronics system achieves a timing resolution of 60 ps FWHM. Prototype TOF detector modules are read out with the electronics system and give coincidence timing resolutions of 259 ps FWHM and 156 ps FWHM for detector modules coupled to LSO and LaBr3 crystals respectively. PMID:24575149

  18. High-performance electronics for time-of-flight PET systems

    PubMed Central

    Choong, W.-S.; Peng, Q.; Vu, C.Q.; Turko, B.T.; Moses, W.W.

    2014-01-01

    We have designed and built a high-performance readout electronics system for time-of-flight positron emission tomography (TOF PET) cameras. The electronics architecture is based on the electronics for a commercial whole-body PET camera (Siemens/CPS Cardinal electronics), modified to improve the timing performance. The fundamental contributions in the electronics that can limit the timing resolution include the constant fraction discriminator (CFD), which converts the analog electrical signal from the photo-detector to a digital signal whose leading edge is time-correlated with the input signal, and the time-to-digital converter (TDC), which provides a time stamp for the CFD output. Coincident events are identified by digitally comparing the values of the time stamps. In the Cardinal electronics, the front-end processing electronics are performed by an Analog subsection board, which has two application-specific integrated circuits (ASICs), each servicing a PET block detector module. The ASIC has a built-in CFD and TDC. We found that a significant degradation in the timing resolution comes from the ASIC’s CFD and TDC. Therefore, we have designed and built an improved Analog subsection board that replaces the ASIC’s CFD and TDC with a high-performance CFD (made with discrete components) and TDC (using the CERN high-performance TDC ASIC). The improved Analog subsection board is used in a custom single-ring LSO-based TOF PET camera. The electronics system achieves a timing resolution of 60 ps FWHM. Prototype TOF detector modules are read out with the electronics system and give coincidence timing resolutions of 259 ps FWHM and 156 ps FWHM for detector modules coupled to LSO and LaBr3 crystals respectively. PMID:24575149

  19. EndoTOFPET-US - A Miniaturised Calorimeter for Endoscopic Time-of-Flight Positron Emission Tomography

    NASA Astrophysics Data System (ADS)

    Zvolský, Milan; EndoTOFPET-US Collaboration

    2015-02-01

    In the scope of the EndoTOFPET-US project, a novel multimodal device for Ultrasound (US) Endoscopy and Positron Emission Tomography (PET) is being developed. The project aims at detecting and quantifying morphologic and functional markers and developing new biomarkers for pancreas and prostate oncology. Exploiting the Time-of-Flight (TOF) information of the gamma rays allows for a more sensitive, more precise and lower radiation- dose imaging and intervention on small internal structures. The detection of the gamma rays is realised with the help of scintillator crystals with Silicon Photomultiplier (SiPM) read-out, aiming at a coincidence time resolution of 200 ps and a spatial resolution of ≈ 1 mm. For the endoscopic detector, digital SiPMs are utilised for the first time in an instrument planned for clinical applications. The functionality of the instrument as well as the challenges that accompany the high miniaturisation of the endoscopic detector and the asymmetric and variable geometry of the system, are presented. The demands on the system involve the fields of scintillating crystallography, ultra-fast photon detection, highly integrated electronics, system integration as well as image reconstruction. The single detector components have been fully characterised and are performing up to specifications. Two dedicated ASIC chips have been developed for the project. The first PET images have been acquired with a test setup that consists solely of hardware and software developed within the collaboration and demonstrate that the data acquisition and reconstruction chain is operational. In this talk, the characterisation of the single components and the status of the detector integration and comissioning is presented.

  20. The National Ignition Facility neutron time-of-flight system and its initial performance (invited)a)

    NASA Astrophysics Data System (ADS)

    Glebov, V. Yu.; Sangster, T. C.; Stoeckl, C.; Knauer, J. P.; Theobald, W.; Marshall, K. L.; Shoup, M. J.; Buczek, T.; Cruz, M.; Duffy, T.; Romanofsky, M.; Fox, M.; Pruyne, A.; Moran, M. J.; Lerche, R. A.; McNaney, J.; Kilkenny, J. D.; Eckart, M. J.; Schneider, D.; Munro, D.; Stoeffl, W.; Zacharias, R.; Haslam, J. J.; Clancy, T.; Yeoman, M.; Warwas, D.; Horsfield, C. J.; Bourgade, J.-L.; Landoas, O.; Disdier, L.; Chandler, G. A.; Leeper, R. J.

    2010-10-01

    The National Ignition Facility (NIF) successfully completed its first inertial confinement fusion (ICF) campaign in 2009. A neutron time-of-flight (nTOF) system was part of the nuclear diagnostics used in this campaign. The nTOF technique has been used for decades on ICF facilities to infer the ion temperature of hot deuterium (D2) and deuterium-tritium (DT) plasmas based on the temporal Doppler broadening of the primary neutron peak. Once calibrated for absolute neutron sensitivity, the nTOF detectors can be used to measure the yield with high accuracy. The NIF nTOF system is designed to measure neutron yield and ion temperature over 11 orders of magnitude (from 108 to 1019), neutron bang time in DT implosions between 1012 and 1016, and to infer areal density for DT yields above 1012. During the 2009 campaign, the three most sensitive neutron time-of-flight detectors were installed and used to measure the primary neutron yield and ion temperature from 25 high-convergence implosions using D2 fuel. The OMEGA yield calibration of these detectors was successfully transferred to the NIF.

  1. A high resolving power multiple reflection matrix-assisted laser desorption/ionization time-of-flight mass spectrometer.

    PubMed

    Piyadasa, C K; Håkansson, P; Ariyaratne, T R

    1999-01-01

    Two electrostatic mirrors, mounted symmetrically on the same optical axis facing each other, are used to increase the time-of-flight of molecular ions produced in matrix-assisted laser desorption/ionization (MALDI). The mirrors, which are used in the non-compensating mode, are located between a MALDI ion source and a stop detector. The source is operated at 10.5 kV acceleration voltage using the delayed extraction technique. The high voltage for the mirror arrangement is switched on after the desorption event when the molecular ions have drifted into the region between the mirrors. The ions are trapped by successive reflections of the opposite electrostatic fields in the mirrors until the electric fields are switched off. The number of reflections depends on the speed of the ions when they enter the mirror trap and the ontime of the mirrors. When the electric fields are removed during the motion of the ions towards the stop detector, the ions penetrate the grids of the mirror and reach that detector. The extension of the flight path due to the number of reflections is used to increase the resolving power in time-of-flight spectra. Values of 55,000 for substance-P (MW 1346.7) and 31,000 for bovine insulin (MW 5734) were obtained for single laser shot spectra. PMID:10230069

  2. Reconstruction of Time-Resolved Neutron Energy Spectra in Z-Pinch Experiments Using Time-of-flight Method

    SciTech Connect

    Rezac, K.; Klir, D.; Kubes, P.; Kravarik, J.

    2009-01-21

    We present the reconstruction of neutron energy spectra from time-of-flight signals. This technique is useful in experiments with the time of neutron production in the range of about tens or hundreds of nanoseconds. The neutron signals were obtained by a common hard X-ray and neutron fast plastic scintillation detectors. The reconstruction is based on the Monte Carlo method which has been improved by simultaneous usage of neutron detectors placed on two opposite sides from the neutron source. Although the reconstruction from detectors placed on two opposite sides is more difficult and a little bit inaccurate (it followed from several presumptions during the inclusion of both sides of detection), there are some advantages. The most important advantage is smaller influence of scattered neutrons on the reconstruction. Finally, we describe the estimation of the error of this reconstruction.

  3. SENJU: a new time-of-flight single-crystal neutron diffractometer at J-PARC

    PubMed Central

    Ohhara, Takashi; Kiyanagi, Ryoji; Oikawa, Kenichi; Kaneko, Koji; Kawasaki, Takuro; Tamura, Itaru; Nakao, Akiko; Hanashima, Takayasu; Munakata, Koji; Moyoshi, Taketo; Kuroda, Tetsuya; Kimura, Hiroyuki; Sakakura, Terutoshi; Lee, Chang-Hee; Takahashi, Miwako; Ohshima, Ken-ichi; Kiyotani, Tamiko; Noda, Yukio; Arai, Masatoshi

    2016-01-01

    SENJU is a new single-crystal time-of-flight neutron diffractometer installed at BL18 at the Materials and Life Science Experimental Facility of the Japan Accelerator Research Complex (J-PARC). The diffractometer was designed for precise crystal and magnetic structure analyses under multiple extreme sample environments such as low temperature, high pressure and high magnetic field, and for diffraction measurements of small single crystals down to 0.1 mm3 in volume. SENJU comprises three choppers, an elliptical shape straight supermirror guide, a vacuum sample chamber and 37 scintillator area detectors. The moderator-to-sample distance is 34.8 m, and the sample-to-detector distance is 800 mm. The wavelength of incident neutrons is 0.4–4.4 Å (first frame). Because short-wavelength neutrons are available and the large solid angle around the sample position is covered by the area detectors, a large reciprocal space can be simultaneously measured. Furthermore, the vacuum sample chamber and collimator have been designed to produce a very low background level. Thus, the measurement of a small single crystal is possible. As sample environment devices, a newly developed cryostat with a two-axis (ω and φ axes) goniometer and some extreme environment devices, e.g. a vertical-field magnet, high-temperature furnace and high-pressure cell, are available. The structure analysis of a sub-millimetre size (0.1 mm3) single organic crystal, taurine, and a magnetic structure analysis of the antiferromagnetic phase of MnF2 have been performed. These results demonstrate that SENJU can be a powerful tool to promote materials science research. PMID:26937237

  4. Upgrade of the time-of-flight diffractometer EPSILON

    NASA Astrophysics Data System (ADS)

    Ulyanov, V.; Walther, K.; Kuznetsov, I.; Frischbutter, A.; Medvedev, E.; Scheffzük, Ch.; Schebetov, A.

    At beam line 7A of the pulsed reactor IBR-2 (JINR Dubna) the strain diffractometer EPSILON has been working for several years. Due to a flight path of 102m a good resolution (Δd/d<3×10-3) was achieved. Nevertheless, further improvements of the instrument were required because of intended studies on geological samples. The modernisation of EPSILON is a renewal of the whole recording system, including collimators and detectors. The two previously used Soller collimators are replaced by nine radial collimators. Each collimator consists of 48 gadolinium oxide coated mylar foils with an angular distance of about 20' of arc to each other and therefore covers a range of nearly 16° for 2Θ. In the other direction a range of about 18° is covered. Three collimators in each case are grouped into a unit covering 66° in the plane perpendicular to the incident beam. Single 3He counter tubes with a diameter of 10mm and an active length of 120mm are used. Each collimator/detector block is mounted on a ring carrier with its surface perpendicular to the incident neutron beam. All blocks have the possibility of adjustment in three directions. The transparency of the collimators is about 90-95%.

  5. Development and Applications of Time of Flight Neutron Depth Profiling

    SciTech Connect

    Bingham Cady; Kenan Unlu

    2005-03-17

    The depth profiles of intentional or intrinsic constituents of a sample provide valuable information for the characterization of materials. For example, the subtle differences in spatial distribution and composition of many chemical species in the near surface region and across interfacial boundaries can significantly alter the electronic and optical properties of materials. A number of analytical techniques for depth profiling have been developed during the last two decades. neutron Depth Profiling (NDP) is one of the leading analytical techniques. The NDP is a nondestructive near surface technique that utilizes thermal/cold neutron beam to measure the concentration of specific light elements versus their depth in materials. The depth is obtained from the energy loss of protons, alphas or recoil atoms in substrate materials. Since the charged particle energy determination using surface barrier detector is used for NDP, the depth resolution is highly dependent on the detectors an d detection instruments. The depth resolutions of a few tens of nm are achieved with available NDP facilities in the world. However, the performance of NDP needs to be improved in order to obtain a few A depth resolutions.

  6. Neutron time-of-flight spectroscopy measurement using a waveform digitizer

    NASA Astrophysics Data System (ADS)

    Liu, Long-Xiang; Wang, Hong-Wei; Ma, Yu-Gang; Cao, Xi-Guang; Cai, Xiang-Zhou; Chen, Jin-Gen; Zhang, Gui-Lin; Han, Jian-Long; Zhang, Guo-Qiang; Hu, Ji-Feng; Wang, Xiao-He

    2016-05-01

    The photoneutron source (PNS, phase 1), an electron linear accelerator (linac)-based pulsed neutron facility that uses the time-of-flight (TOF) technique, was constructed for the acquisition of nuclear data from the Thorium Molten Salt Reactor (TMSR) at the Shanghai Institute of Applied Physics (SINAP). The neutron detector signal used for TOF calculation, with information on the pulse arrival time, pulse shape, and pulse height, was recorded by using a waveform digitizer (WFD). By using the pulse height and pulse-shape discrimination (PSD) analysis to identify neutrons and γ-rays, the neutron TOF spectrum was obtained by employing a simple electronic design, and a new WFD-based DAQ system was developed and tested in this commissioning experiment. The DAQ system developed is characterized by a very high efficiency with respect to millisecond neutron TOF spectroscopy. Supported by Strategic Priority Research Program of the Chinese Academy of Science(TMSR) (XDA02010100), National Natural Science Foundation of China(NSFC)(11475245,No.11305239), Shanghai Key Laboratory of Particle Physics and Cosmology (11DZ2260700)

  7. TOF (time-of-flight) measurements of pulsed neutrons for texture analysis of low symmetry materials

    SciTech Connect

    Larson, A.C.; Vergamini, P.J.; Lujan, M. Jr. ); Wenk, H.R. . Dept. of Geology and Geophysics)

    1989-01-01

    The single crystal diffractometer at LANSCE, SCD, provides and ideal capability for the study of preferred orientation in geological samples by time-of flight (TOF) measurement of pulsed neutrons. The 2-d position sensitive neutron detector with the large wave length range allows one to measure the complete distribution of intensities for several poles very quickly. Each histogram covers about {pi}{sup 2}/16 radians of reciprocal space and contains information from all possible poles visible with the wave length range used, usually about 0.5 to 5.0{Angstrom}. With this method complete pole figures of many lattice planes can be constructed from only 12 to 20 sample orientations as compared to over 1000 sample settings per lattice plane using conventional diffractometers. Pole figures from measurements of experimentally deformed standard samples of calcite and quartzite with known history of deformation provide information about deformation mechanisms and their temperature/strain history. This information can be applied to interpret preferred orientation of naturally deformed rocks. 6 refs., 10 figs.

  8. Time-of-flight measurement in the DZero Central Fiber Tracker

    SciTech Connect

    Juan Estrada et al.

    2003-12-19

    We continue evaluation of the new electronics developed for the Central Fiber Tracker and Preshower detectors. With the custom TriP chip and MCM II we have measured the position of the hits along the fiber by comparing the time of arrival of the photons at the VLPC with the expected timing relative to the beam. The measured rms resolution at the center of the fibers is 46cm for hits with more than 8 photo-electrons and is dominated by the statistics of photon arrival time. The corresponding resolution near the ends of the fibers (where more photoelectrons are collected) is calculated to be of order 27cm. With a second submission of the TriP chip to add the time-of-flight measuring capability we will effectively double the number of channels in the central fiber tracker. This capability will increase the maximum luminosity at which D0 can do tracking from {approx} 100 {center_dot} 10{sup 30}cm{sup -2}s{sup -1} to {approx} 200 {center_dot} 10{sup 30} cm{sup -2}s{sup -1} (at a bench mark tracking specification). The cost of replacing the electronics is of order $500K and the necessary lead time is 1.5 years.

  9. Combining endoscopic ultrasound with Time-Of-Flight PET: The EndoTOFPET-US Project

    NASA Astrophysics Data System (ADS)

    Frisch, Benjamin

    2013-12-01

    The EndoTOFPET-US collaboration develops a multimodal imaging technique for endoscopic exams of the pancreas or the prostate. It combines the benefits of high resolution metabolic imaging with Time-Of-Flight Positron Emission Tomography (TOF PET) and anatomical imaging with ultrasound (US). EndoTOFPET-US consists of a PET head extension for a commercial US endoscope and a PET plate outside the body in coincidence with the head. The high level of miniaturization and integration creates challenges in fields such as scintillating crystals, ultra-fast photo-detection, highly integrated electronics, system integration and image reconstruction. Amongst the developments, fast scintillators as well as fast and compact digital SiPMs with single SPAD readout are used to obtain the best coincidence time resolution (CTR). Highly integrated ASICs and DAQ electronics contribute to the timing performances of EndoTOFPET. In view of the targeted resolution of around 1 mm in the reconstructed image, we present a prototype detector system with a CTR better than 240 ps FWHM. We discuss the challenges in simulating such a system and introduce reconstruction algorithms based on graphics processing units (GPU).

  10. Novel time-of-flight spectrometer for the analysis of positron annihilation induced Auger electrons

    SciTech Connect

    Hugenschmidt, Christoph; Legl, Stefan

    2006-10-15

    Positron annihilation induced Auger-electron spectroscopy (PAES) has several advantages over conventional Auger-electron spectroscopy such as extremely high surface sensitivity and outstanding signal-to-noise ratio at the Auger-transition energy. In order to benefit from these prominent features a low-energy positron beam of high intensity is required for surface sensitive PAES studies. In addition, an electron energy analyzer is required, which efficiently detects the Auger electrons with acceptable energy resolution. For this reason a novel time-of-flight (TOF) spectrometer has been developed at the intense positron source NEPOMUC that allows PAES studies within short measurement time. This TOF-PAES setup combines a trochoidal filter and a flight tube in a Faraday cage in order to achieve an improved energy resolution of about 1 eV at high electron energies up to E{approx_equal}1000 eV. The electron flight time is the time between the annihilation radiation at the sample and when the electron hits a microchannel plate detector at the end of the flight tube.

  11. Enhancing MALDI Time-Of-Flight Mass Spectrometer Performance through Spectrum Averaging

    PubMed Central

    Mitchell, Morgan; Mali, Sujina; King, Charles C.; Bark, Steven J.

    2015-01-01

    Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometers are simple and robust mass spectrometers used for analysis of biologically relevant molecules in diverse fields including pathogen identification, imaging mass spectrometry, and natural products chemistry. Despite high nominal resolution and accuracy, we have observed significant variability where 30–50% of individual replicate measurements have errors in excess of 5 parts-per-million, even when using 5-point internal calibration. Increasing the number of laser shots for each spectrum did not resolve this observed variability. What is responsible for our observed variation? Using a modern MALDI-TOF/TOF instrument, we evaluated contributions to variability. Our data suggest a major component of variability is binning of the raw flight time data by the electronics and clock speed of the analog-to-digital (AD) detection system, which requires interpolation by automated peak fitting algorithms and impacts both calibration and the observed mass spectrum. Importantly, the variation observed is predominantly normal in distribution, which implies multiple components contribute to the observed variation and suggests a method to mitigate this variability through spectrum averaging. Restarting the acquisition impacts each spectrum within the electronic error of the AD detector system and defines a new calibration function. Therefore, averaging multiple independent spectra and not a larger number of laser shots leverages this inherent binning error to mitigate variability in accurate MALDI-TOF mass measurements. PMID:25798583

  12. The Time of Flight Upgrade for CLAS at 12 GeV

    SciTech Connect

    Graham, Lewis

    2007-10-26

    The Time of Flight (TOF) system is a detection system within the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson National Accelerator Facility. CLAS, being a magnetic toroidal multi-gap spectrometer, is used in the detection of particles and their varying properties. Jefferson National Accelerator Facility is providing an incoming electron beam of energy 6 GeV that is used to probe the structure and production of these particles. The CLAS detector is currently adapted to energies of up to 6 GeV, but with recent approval it will now upgrade to energies of 12 GeV. CLAS consists of drift chambers to determine the charged particle paths, gas Cherenkov counters for electron discrimination, TOF scintillators for particle identification, and an electromagnetic calorimeter for identifying showering electrons and photons. The TOF system, which is our focus, is composed of scintillation counters at the forward angle, and covers an area of 206 meters squared. Therefore, we look to upgrade and construct the TOF system of CLAS and outline strategies of current construction, purpose for design, and outlook for the TOF system upgrade.

  13. Electron stimulated desorption of negative ions: A time-of-flight experiment

    NASA Astrophysics Data System (ADS)

    Goeden, C.; Dollinger, G.

    2002-08-01

    We present a setup for stimulated desorption experiments of negative ions using low energy incident electrons and time-of-flight identification of the desorbed ions. It consists of a pulsed electron gun, an electrostatic focusing system, and a channel plate detector setup. Electron beams down to sub-eV energies can be used due to electrostatic shielding and the compensation of the earth's magnetic field by a set of Helmholtz coils. The main advantage is the large acceptance for ions of all masses, energies, and desorption angles at the same time, which keeps measuring time reasonably short and allows us to gain information before degeneration of the irradiated sample occurs, even if weak desorption channels are investigated. We demonstrate the power of our setup with first results from a boron doped, (100)-oriented diamond sample, which is partly oxidized and partly hydrogenated with some water contaminations on it. Different binding states of oxygen are disclosed clearly by different desorption thresholds. The C-O binding on oxidized diamond forms a carbonyl group. The 1b2 orbital of water can be seen in a O desorption threshold. The yield of negative hydrogen desorption shows a linear increase for incident electron energies higher than 13 eV. It results from a dipolar dissociation as has been published previously.

  14. The Time of Flight Upgrade for CLAS at 12 GeV

    SciTech Connect

    Lewis Graham

    2007-10-01

    The Time of Flight (TOF) system is a detection system within the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson National Accelerator Facility. CLAS, being a magnetic toroidal multi-gap spectrometer, is used in the detection of particles and their varying properties. Jefferson National Accelerator Facility is providing an incoming electron beam of energy 6 GeV that is used to probe the structure and production of these particles. The CLAS detector is currently adapted to energies of up to 6 GeV, but with recent approval it will now upgrade to energies of 12 GeV. CLAS consists of drift chambers to determine the charged particle paths, gas Cherenkov counters for electron discrimination, TOF scintillators for particle identification, and an electromagnetic calorimeter for identifying showering electrons and photons. The TOF system, which is our focus, is composed of scintillation counters at the forward angle, and covers an area of 206 meters squared. Therefore, we look to upgrade and construct the TOF system of CLAS and outline strategies of current construction, purpose for design, and outlook for the TOF system upgrade

  15. Crystal timing offset calibration method for time of flight PET scanners

    NASA Astrophysics Data System (ADS)

    Ye, Jinghan; Song, Xiyun

    2016-03-01

    In time-of-flight (TOF) positron emission tomography (PET), precise calibration of the timing offset of each crystal of a PET scanner is essential. Conventionally this calibration requires a specially designed tool just for this purpose. In this study a method that uses a planar source to measure the crystal timing offsets (CTO) is developed. The method uses list mode acquisitions of a planar source placed at multiple orientations inside the PET scanner field-of-view (FOV). The placement of the planar source in each acquisition is automatically figured out from the measured data, so that a fixture for exactly placing the source is not required. The expected coincidence time difference for each detected list mode event can be found from the planar source placement and the detector geometry. A deviation of the measured time difference from the expected one is due to CTO of the two crystals. The least squared solution of the CTO is found iteratively using the list mode events. The effectiveness of the crystal timing calibration method is evidenced using phantom images generated by placing back each list mode event into the image space with the timing offset applied to each event. The zigzagged outlines of the phantoms in the images become smooth after the crystal timing calibration is applied. In conclusion, a crystal timing calibration method is developed. The method uses multiple list mode acquisitions of a planar source to find the least squared solution of crystal timing offsets.

  16. Enhancing MALDI time-of-flight mass spectrometer performance through spectrum averaging.

    PubMed

    Mitchell, Morgan; Mali, Sujina; King, Charles C; Bark, Steven J

    2015-01-01

    Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometers are simple and robust mass spectrometers used for analysis of biologically relevant molecules in diverse fields including pathogen identification, imaging mass spectrometry, and natural products chemistry. Despite high nominal resolution and accuracy, we have observed significant variability where 30-50% of individual replicate measurements have errors in excess of 5 parts-per-million, even when using 5-point internal calibration. Increasing the number of laser shots for each spectrum did not resolve this observed variability. What is responsible for our observed variation? Using a modern MALDI-TOF/TOF instrument, we evaluated contributions to variability. Our data suggest a major component of variability is binning of the raw flight time data by the electronics and clock speed of the analog-to-digital (AD) detection system, which requires interpolation by automated peak fitting algorithms and impacts both calibration and the observed mass spectrum. Importantly, the variation observed is predominantly normal in distribution, which implies multiple components contribute to the observed variation and suggests a method to mitigate this variability through spectrum averaging. Restarting the acquisition impacts each spectrum within the electronic error of the AD detector system and defines a new calibration function. Therefore, averaging multiple independent spectra and not a larger number of laser shots leverages this inherent binning error to mitigate variability in accurate MALDI-TOF mass measurements. PMID:25798583

  17. Measurement of the Spatial Distribution of Ultracold Cesium Rydberg Atoms by Time-of-Flight Spectroscopy

    NASA Astrophysics Data System (ADS)

    Li, Jingkui; Zhang, Linjie; Zhang, Hao; Zhao, Jianming; Jia, Suotang

    2015-09-01

    We prepare nS (n = 49) cesium Rydberg atoms by two-photon excitation in a standard magnetooptical trap to obtain the spatial distribution of the Rydberg atoms by measuring the time-of-flight (TOF) spectra in the case of a low Rydberg density. We analyze the time evolution of the ultracold nS Rydberg atoms distribution by changing the delay time of the pulsed ionization field, defined as the duration from the moment of switching off the excitation lasers to the time of switching on the ionization field. TOF spectra of Rydberg atoms are observed as a function of the delay time and initial Rydberg atomic density. The corresponding full widths at half maximum (FWHMs) are obtained by fitting the spectra with a Gaussian profile. The FWHM decreases with increasing delay time at a relatively high Rydberg atom density (>5 × 107/cm3) because of the decreasing Coulomb interaction between released charges during their flight to the detector. The temperature of the cold atoms is deduced from the dependence of the TOF spectra on the delay time under the condition of low Rydberg atom density.

  18. Simple peak shift analysis of time-of-flight data with a slow instrumental response function.

    PubMed

    Nishimura, Goro; Tamura, Mamoru

    2005-01-01

    Analysis of time-of-flight (TOF) data is sometimes limited by the instrumental response function, and optical parameters are extracted from the observed response curve by several mathematical methods, such as deconvolution. In contrast to this, we demonstrate that a method using shifts of the peak time of the response curve with different source-detector separations can yield the average path length of the light traveling in a tissue-like sample without deconvolution. In addition, combining the intensity information allows us to separate the scattering and absorption coefficients. This simple method is more robust in signal-to-noise ratio than the moment analysis, which also does not require the deconvolution procedure, because the peak position is not significantly dependent on the baseline fluctuation and the contamination of the scattering. The analysis is demonstrated by TOF measurements of an Intralipid solution at 800 nm, and is applied to the measurements at 1.29 microm, where the temporal response of photomultiplier tubes is not sufficiently good. PMID:15847597

  19. STiC — a mixed mode silicon photomultiplier readout ASIC for time-of-flight applications

    NASA Astrophysics Data System (ADS)

    Harion, T.; Briggl, K.; Chen, H.; Fischer, P.; Gil, A.; Kiworra, V.; Ritzert, M.; Schultz-Coulon, H.-C.; Shen, W.; Stankova, V.

    2014-02-01

    STiC is an application specific integrated circuit (ASIC) for the readout of silicon photomultipliers. The chip has been designed to provide a very high timing resolution for time-of-flight applications in medical imaging and particle physics. It is dedicated in particular to the EndoToFPET-US project, which is developing an endoscopic PET detector combined with ultrasound imaging for early pancreas and prostate cancer detection. This PET system aims to provide a spatial resolution of 1 mm and a time-of-flight resolution of 200 ps FWHM. The analog frontend of STiC can use either a differential or single ended connection to the SiPM. The time and energy information of the detector signal is encoded into two time stamps. A special linearized time-over-threshold method is used to obtain a linear relation between the signal charge and the measured signal width, improving the energy resolution. The trigger signals are digitized by an integrated TDC module with a resolution of less than 20 ps. The TDC data is stored in an internal memory and transfered over a 160 MBit/s serial link using 8/10 bit encoding. First coincidence measurements using a 3.1 × 3.1 × 15 mm3 LYSO crystal and a S10362-33-50 Hamamtsu MPPC show a coincidence time resolution of less than 285 ps. We present details on the chip design as well as first characterization measurements.

  20. Potential of monitoring isotopologues by quantitative gas chromatography with time-of-flight mass spectrometry for metabolomic assay.

    PubMed

    Wang, Yi; Hu, Haiyan; Su, Yue; Zhang, Fang; Guo, Yinlong

    2016-03-01

    Because of the extreme complexity of metabolomic samples, the effectiveness of quantitative gas chromatography with time-of-flight mass spectrometry depends substantially on the expansion of the linear dynamic range. Facing the existence of numerous saturated detector signals, a data processing method based on monitoring isotopologues has been developed. The monoisotopic ion kept the high mass spectrometry sensitivity, and the less abundant isotopologue ions extended the linear dynamic range. This alternative method was proved to extend the linear dynamic range to five orders of magnitude successfully and overcome the quantitative problems induced by the ion detector saturation. Finally, to validate the applicability, the method was applied to a metabolomic assay of Alzheimer's disease. Comparing with the traditional monoisotopic method, the use of monitoring isotopologues helped us to discover an additional eight metabolites with significant difference and to conduct a more reliable principal component analysis as well. The results demonstrated that monitoring isotopologues in quantitative gas chromatography with time-of-flight mass spectrometry could improve the authenticity of metabolomic analysis. PMID:26763370

  1. Development of analytically capable time-of-flight mass spectrometer with continuous ion introduction

    NASA Astrophysics Data System (ADS)

    Hárs, György; Dobos, Gábor

    2010-03-01

    The present article describes the results and findings explored in the course of the development of the analytically capable prototype of continuous time-of-flight (CTOF) mass spectrometer. Currently marketed pulsed TOF (PTOF) instruments use ion introduction with a 10 ns or so pulse width, followed by a waiting period roughly 100 μs. Accordingly, the sample is under excitation in 10-4 part of the total measuring time. This very low duty cycle severely limits the sensitivity of the PTOF method. A possible approach to deal with this problem is to use linear sinusoidal dual modulation technique (CTOF) as described in this article. This way the sensitivity of the method is increased, due to the 50% duty cycle of the excitation. All other types of TOF spectrometer use secondary electron multiplier (SEM) for detection, which unfortunately discriminates in amplification in favor of the lighter ions. This discrimination effect is especially undesirable in a mass spectrometric method, which targets high mass range. In CTOF method, SEM is replaced with Faraday cup detector, thus eliminating the mass discrimination effect. Omitting SEM is made possible by the high ion intensity and the very slow ion detection with some hundred hertz detection bandwidth. The electrometer electronics of the Faraday cup detector operates with amplification 1010 V/A. The primary ion beam is highly monoenergetic due to the construction of the ion gun, which made possible to omit any electrostatic mirror configuration for bunching the ions. The measurement is controlled by a personal computer and the intelligent signal generator Type Tabor WW 2571, which uses the direct digital synthesis technique for making arbitrary wave forms. The data are collected by a Labjack interface board, and the fast Fourier transformation is performed by the software. Noble gas mixture has been used to test the analytical capabilities of the prototype setup. Measurement presented proves the results of the mathematical

  2. Development of analytically capable time-of-flight mass spectrometer with continuous ion introduction

    SciTech Connect

    Hars, Gyoergy; Dobos, Gabor

    2010-03-15

    The present article describes the results and findings explored in the course of the development of the analytically capable prototype of continuous time-of-flight (CTOF) mass spectrometer. Currently marketed pulsed TOF (PTOF) instruments use ion introduction with a 10 ns or so pulse width, followed by a waiting period roughly 100 {mu}s. Accordingly, the sample is under excitation in 10{sup -4} part of the total measuring time. This very low duty cycle severely limits the sensitivity of the PTOF method. A possible approach to deal with this problem is to use linear sinusoidal dual modulation technique (CTOF) as described in this article. This way the sensitivity of the method is increased, due to the 50% duty cycle of the excitation. All other types of TOF spectrometer use secondary electron multiplier (SEM) for detection, which unfortunately discriminates in amplification in favor of the lighter ions. This discrimination effect is especially undesirable in a mass spectrometric method, which targets high mass range. In CTOF method, SEM is replaced with Faraday cup detector, thus eliminating the mass discrimination effect. Omitting SEM is made possible by the high ion intensity and the very slow ion detection with some hundred hertz detection bandwidth. The electrometer electronics of the Faraday cup detector operates with amplification 10{sup 10} V/A. The primary ion beam is highly monoenergetic due to the construction of the ion gun, which made possible to omit any electrostatic mirror configuration for bunching the ions. The measurement is controlled by a personal computer and the intelligent signal generator Type Tabor WW 2571, which uses the direct digital synthesis technique for making arbitrary wave forms. The data are collected by a Labjack interface board, and the fast Fourier transformation is performed by the software. Noble gas mixture has been used to test the analytical capabilities of the prototype setup. Measurement presented proves the results of

  3. Concept for a time-of-flight Small Angle Neutron Scattering instrument at the European Spallation Source

    NASA Astrophysics Data System (ADS)

    Jaksch, S.; Martin-Rodriguez, D.; Ostermann, A.; Jestin, J.; Duarte Pinto, S.; Bouwman, W. G.; Uher, J.; Engels, R.; Frielinghaus, H.

    2014-10-01

    A new Small Angle Neutron Scattering instrument is proposed for the European Spallation Source. The pulsed source requires a time-of-flight analysis of the gathered neutrons at the detector. The optimal instrument length is found to be rather large, which allows for a polarizer and a versatile collimation. The polarizer allows for studying magnetic samples and incoherent background subtraction. The wide collimation will host VSANS and SESANS options that increase the resolution of the instrument towards μm and tens of μm, respectively. Two 1 m2 area detectors will cover a large solid angle simultaneously. The expected gains for this new instrument will lie in the range between 20 and 36, depending on the assessment criteria, when compared to up-to-date reactor based instruments. This will open new perspectives for fast kinetics, weakly scattering samples, and multi-dimensional contrast variation studies.

  4. Research and development on a sub 100 PICO second time-of-flight system based on silicon avalanche diodes

    SciTech Connect

    Choi, Y.; Hirsch, A.; Hauger, A.; Scharenberg, R.; Tincknell, M.; Rai, G.

    1991-12-31

    Particle identification requires a momentum measurement and a second independent determination either energy loss (dE/dx) or time of flight (TOF). To cover a momentum range from 0.1 GeV/c to 1.5 GeV/c in the STAR detector requires both the dE/dx and TOF techniques. This research is designed to develop the avalanche diode (AVD) detectors for TOF systems and evaluate their performance. The test of a small prototype system would be carried out at Purdue and at accelerator test beam sites. The Purdue group has developed a complete test setup for evaluating the time resolution of the AVD`s which includes fast-slow electronic channels, CAMAC based electronic modules and a temperature controlled environment. The AVDs also need to be tested in a 0.5 tesla magnetic field. The Purdue group would augment this test set up to include a magnetic field.

  5. Changing Images of Alice.

    ERIC Educational Resources Information Center

    Cleaver, Betty P.; Erdman, Barbara

    This paper examines the depiction of Alice in illustrated versions of "Alice in Wonderland" by Lewis Carroll. The primary concern was to determine if the character of Alice had changed historically through the interpretation of different illustrators and to determine what the changes were and what their impact might have on the interpretation of…

  6. High-performance multiple-reflection time-of-flight mass spectrometers for research with exotic nuclei and for analytical mass spectrometry

    NASA Astrophysics Data System (ADS)

    Plaß, Wolfgang R.; Dickel, Timo; Ayet San Andres, Samuel; Ebert, Jens; Greiner, Florian; Hornung, Christine; Jesch, Christian; Lang, Johannes; Lippert, Wayne; Majoros, Tamas; Short, Devin; Geissel, Hans; Haettner, Emma; Reiter, Moritz P.; Rink, Ann-Kathrin; Scheidenberger, Christoph; Yavor, Mikhail I.

    2015-11-01

    A class of multiple-reflection time-of-flight mass spectrometers (MR-TOF-MSs) has been developed for research with exotic nuclei at present and future accelerator facilities such as GSI and FAIR (Darmstadt), and TRIUMF (Vancouver). They can perform highly accurate mass measurements of exotic nuclei, serve as high-resolution, high-capacity mass separators and be employed as diagnostics devices to monitor the production, separation and manipulation of beams of exotic nuclei. In addition, a mobile high-resolution MR-TOF-MS has been developed for in situ applications in analytical mass spectrometry ranging from environmental research to medicine. Recently, the MR-TOF-MS for GSI and FAIR has been further developed. A novel RF quadrupole-based ion beam switchyard has been developed that allows merging and splitting of ion beams as well as transport of ions into different directions. It efficiently connects a test and reference ion source and an auxiliary detector to the system. Due to an increase in the kinetic energy of the ions in the time-of-flight analyzer of the MR-TOF-MS, a given mass resolving power is now achieved in less than half the time-of-flight. Conversely, depending on the time-of-flight, the mass resolving power has been increased by a factor of more than two.

  7. Rapid screening of transferrin-binders in the flowers of Bauhinia blakeana Dunn by on-line high-performance liquid chromatography-diode-array detector-electrospray ionization-ion-trap-time-of-flight-mass spectrometry-transferrin-fluorescence detection system.

    PubMed

    Liu, Meixian; Dong, Jing; Lin, Zongtao; Niu, Yanyan; Zhang, Xiaotian; Jiang, Haixiu; Guo, Ning; Li, Wei; Wang, Hong; Chen, Shizhong

    2016-06-10

    Transferrin (Transferrin, TRF, TF) has drawn increasing attention in cancer therapy due to its potential applications in drug delivery. TF receptor, highly expressed in tumor cells, recognizes and transports Fe(3+)-TF into cells to release iron into cytoplasm. Thus, discovering TF-binding compounds has become an active research area and is of great importance for target therapy. In this study, an on-line analysis method was established for screening TF-binding compounds from the flowers of Bauhinia blakeana Dunn using a high-performance liquid chromatography-diode-array detector-multi-stage mass spectrometry-transferrin-fluorescence detector (HPLC-DAD-MS(n)-TF-FLD) method. As a result, 33 of 80 identified or tentatively characterized compounds in the sample were TF-binding active. Twenty-five flavonol glycosides and eight phenolic acids were identified as TF-binders. Twelve of these active compounds together with six standard compounds were used to study the dose-response effects and structure-activity relationships of flavonoids and phenolic acids. The method was validated by vitexin with a good linearity in the range of concentrations used in the study. The limit of detection for vitexin was 0.1596 nmol. Our study indicated that the established method is simple, rapid and sensitive for screening TF-binding active compounds in the extract of Bauhinia blakeana Dunn, and therefore is important for discovering potential anti-cancer ingredients from complex samples for TF related drug delivery. PMID:27178150

  8. Measurement of identified charged hadron spectra in proton-proton collisions using the Inner Tracking System of the ALICE experiment at the LHC

    SciTech Connect

    Biolcati, Emanuele

    2011-05-23

    The measurement of the identified charged hadron p{sub t} spectra using the ITS energy loss signal in the pp data at {radical}(s) = 900 GeV collected by the ALICE experiment at LHC will be discussed. It is performed using the Inner Tracking System (ITS) in stand-alone mode, both for track reconstruction and particle identification, allowing one to detect low momentum particles with p{sub t} below 200 MeV/c. A second method using the tracks reconstructed by both the ITS and the Time Projection Chamber (TPC) has also been developed. The obtained results will be compared with the ones obtained from the TPC and from the Time Of Flight detector and used to extract the mean p{sub t} value.

  9. ALICE and The state of matter at LHC

    ScienceCinema

    None

    2011-10-06

    Assembly and installation of ALICE, the LHC heavy ion experiment dedicated to the study of matter at extreme temperature and pressure, is nearing completion and the commissioning of the detector is well under way. A good time to look back, to the making of ALICE, and to look forward, to the first physics with proton and heavy ion beams.

  10. A weighted optimization approach to time-of-flight sensor fusion.

    PubMed

    Schwarz, Sebastian; Sjostrom, Marten; Olsson, Roger

    2014-01-01

    Acquiring scenery depth is a fundamental task in computer vision, with many applications in manufacturing, surveillance, or robotics relying on accurate scenery information. Time-of-flight cameras can provide depth information in real-time and overcome short-comings of traditional stereo analysis. However, they provide limited spatial resolution and sophisticated upscaling algorithms are sought after. In this paper, we present a sensor fusion approach to time-of-flight super resolution, based on the combination of depth and texture sources. Unlike other texture guided approaches, we interpret the depth upscaling process as a weighted energy optimization problem. Three different weights are introduced, employing different available sensor data. The individual weights address object boundaries in depth, depth sensor noise, and temporal consistency. Applied in consecutive order, they form three weighting strategies for time-of-flight super resolution. Objective evaluations show advantages in depth accuracy and for depth image based rendering compared with state-of-the-art depth upscaling. Subjective view synthesis evaluation shows a significant increase in viewer preference by a factor of four in stereoscopic viewing conditions. To the best of our knowledge, this is the first extensive subjective test performed on time-of-flight depth upscaling. Objective and subjective results proof the suitability of our approach to time-of-flight super resolution approach for depth scenery capture. PMID:24184728

  11. The ALICE Central Trigger Processor (CTP) upgrade

    NASA Astrophysics Data System (ADS)

    Krivda, M.; Alexandre, D.; Barnby, L. S.; Evans, D.; Jones, P. G.; Jusko, A.; Lietava, R.; Pospíšil, J.; Villalobos Baillie, O.

    2016-03-01

    The ALICE Central Trigger Processor (CTP) at the CERN LHC has been upgraded for LHC Run 2, to improve the Transition Radiation Detector (TRD) data-taking efficiency and to improve the physics performance of ALICE. There is a new additional CTP interaction record sent using a new second Detector Data Link (DDL), a 2 GB DDR3 memory and an extension of functionality for classes. The CTP switch has been incorporated directly onto the new LM0 board. A design proposal for an ALICE CTP upgrade for LHC Run 3 is also presented. Part of the development is a low latency high bandwidth interface whose purpose is to minimize an overall trigger latency.

  12. Photon Physics Potential at ALICE

    NASA Astrophysics Data System (ADS)

    Torii, Hisayuki

    2009-10-01

    The ALICE detector has been designed to study the strongly interacting matter created in nucleus-nucleus collisions at the Large Hadron Collider (LHC). In heavy-ion collisions, it is very critical to measure thermal photons, which are known to carry the temperature information of hot created matter. The thermal photon measurements at RHIC are suggesting the systematic study with better photon detectors at LHC. Furthermore, the suppression of high pT hadrons has provided the first strong signature of hot and dense partonic matter created in heavy-ion collisions at RHIC. Therefore, the suppression behavior of various particle species, including photons, up to LHC energy, is a key observable for the study of the hot matter dynamics. The ALICE PHOton Spectrometer (PHOS) consists of 17920 PWO crystals and Avalanche Photo Diode (APD) covering a rapidity range of ±0.3 and an azimuthal range of 100^o. The fine segment structure and small Moliere radius allow to separate two photons from 0̂ decay at pT=30GeV/c with about 100% efficiency and at even higher pT with smaller efficiency. The decay photons from lower pT 0̂ is the largest background in measuring the thermal photons and can be tagged in a very efficient way with a good energy resolution (3%/√E(GeV)). The ALICE EMCAL consists of shashlik lead-scintillator sampling units covering a rapidity range of ±0.7 and an azimuthal range of 110^ o and sits in the opposite coverage azimuthally to PHOS. The jet measurements by EMCAL and other tracking detectors, especially when tagged by a direct photon in the opposite PHOS detector, represent a key probe for investigating jet quenching effects. In this presentation, physics potential with photon detectors at ALICE during the first physics run of LHC will be discussed. The construction and installation status of the photon detectors as well as their expected physics will be presented.

  13. Status of the ALICE experiment at the LHC

    SciTech Connect

    Herrera Corral, G.

    2008-11-13

    The Large Hadron Collider will provide soon, beams of protons and collisions at high energy to the experiments. ALICE stands for A Large Ion Collider Experiment. It is one of the experiments at the Large Hadron Collider. ALICE will be dedicated to the study of heavy ion collisions. The main goal of ALICE is the observation of the transition of ordinary matter into a plasma of quarks and gluons. ALICE consists of 16 systems of detection. Two of them were designed and constructed in Mexico: i) The V0A detector, located at 3.2 mts. from the interaction point and ii) The cosmic ray detector on the top of the magnet. After a quick review of the LHC and the ALICE experiment we will focus on the description of these systems.

  14. Second generation fusion neutron time-of-flight spectrometer at optimized rate for fully digital data acquisition

    SciTech Connect

    Zhang, X. E-mail: jnke1@icloud.com Fan, T.; Yuan, X.; Xie, X.; Chen, Z.; Källne, J.; Gorini, G.; Nocente, M.

    2014-04-15

    The progress on high-rate event recording of data is taken as starting point to revisit the design of fusion neutron spectrometers based on the TOF (time-of-flight) technique. The study performed was aimed at how such instruments for optimized rate (TOFOR) can be further developed to enhance the plasma diagnostic capabilities based on measurement of the 2.5 MeV dd neutron emission from D plasmas, especially the weak spectral components that depend on discrimination of extraneous events. This paper describes a design (TOFOR II) adapted for use with digital wave form recording of all detector pulses providing information on both amplitude (pulse height) and timing. The results of simulations are presented and the performance enhancement is assessed in comparison to the present.

  15. Design of a backscatter 14-MeV neutron time-of-flight spectrometer for experiments at ITER

    SciTech Connect

    Dzysiuk, N.; Hellesen, C.; Conroy, S.; Ericsson, G.; Hjalmarsson, A.; Skiba, M.

    2014-08-21

    Neutron energy spectrometry diagnostics play an important role in present-day experiments related to fusion energy research. Measurements and thorough analysis of the neutron emission from the fusion plasma give information on a number of basic fusion performance quantities, on the condition of the neutron source and plasma behavior. Here we discuss the backscatter Time-of-Flight (bTOF) spectrometer concept as a possible instrument for performing high resolution measurements of 14 MeV neutrons. The instrument is based on two sets of scintillators, a first scatterer exposed to a collimated neutron beam and a second detector set placed in the backward direction. The scintillators of the first set are enriched in deuterium to achieve neutron backscattering. The energy resolution and efficiency of a bTOF instrument have been determined for various geometrical configurations. A preliminary design of optimal geometry for the two scintillator sets has been obtained by Monte Carlo simulations based on the MCNPX code.

  16. Time of flight and the MUSE experiment in the PIM1 Channel at the Paul Sherrer Institute

    NASA Astrophysics Data System (ADS)

    Lin, Wan; MUSE Collaboration

    2015-10-01

    The MUSE experiment in the PIM1 Channel at the Paul Sherrer Institute in Villigen, Switzerland, measures scattering of electrons and muons from a liquid hydrogen target. The intent of the experiment is to deduce from the scattering probabilities whether the radius of the proton is the same when determined from the scattering of the two different particle types. An important technique for the experiment is precise timing measurements, using high precision scintillators and a beam Cerenkov counter. We will describe the motivations for the precise timing measurement. We will present results for the timing measurements from prototype experimental detectors. We will also present results from a simulation program, Geant4, that was used to calculate energy loss corrections to the time of flight determined between the beam Cherenkov counter and the scintillator. This work is supported in part by the U.S. National Science Foundation Grant PHY 1306126 and the Douglass Project for Women in Math, Science, and Engineering.

  17. Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

    SciTech Connect

    Jacobsen, A. S. Salewski, M.; Korsholm, S. B.; Leipold, F.; Nielsen, S. K.; Rasmussen, J.; Stejner, M.; Eriksson, J.; Ericsson, G.; Hjalmarsson, A.

    2014-11-15

    The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR.

  18. Robust real time extraction of plane segments from time-of-flight camera images

    NASA Astrophysics Data System (ADS)

    Dalbah, Yosef; Koltermann, Dirk; Wahl, Friedrich M.

    2014-04-01

    We present a method that extracts plane segments from images of a time-of-flight camera. Future driver assistance systems rely on an accurate description of the vehicle's environment. Time-of-flight cameras can be used for environment perception and for the reconstruction of the environment. Since most structures in urban environments are planar, extracted plane segments from single camera images can be used for the creation of a global map. We present a method for real time detection of planar surface structures from time-of-flight camera data. The concept is based on a planar surface segmentation that serves as the fundament for a subsequent global planar surface extraction. The evaluation demonstrates the ability of the described algorithm to detect planar surfaces form depth data of complex scenarios in real time. We compare our methods to state of the art planar surface extraction algorithms.

  19. ALICE physics --- Theoretical overview

    SciTech Connect

    Alessandro, B.; Aurenche, P.; Baier, R.; Becattini, F.; Botje, M.; Csorgo, T.; de Cataldo, G.; Foka, Y.; Giovannini, A.; Giubellino, P.; Guillet, J.Ph.; Heinz, U.; Hencken, K.; Iancu, E.; Kaidalov, A.B.; Kajantie, K.; Karsch, F.; Koch, V.; Kopeliovich, B.Z.; Kurepin, A.B.; Laine, M.; Lednicky, R.; Mangano, M.; Monteno, M.; Paic, G.; Pilon, E.; Pshenichnov, I.A.; Redlich, K.; Revol, J.-P.; Riggi, F.; Safarik, K.; Salgado, C.A.; Schukraft, J.; Sinyukov, Y.; Tomasik, B.; Treleani, D.; Ugoccioni, R.; Venugopalan, R.; Vogt, R.; Wiedemann, U.A.

    2002-09-15

    ALICE is the dedicated heavy ion experiment at the LHC. This note summarizes theoretical developments in the field of hot and dense matter and their relevance for observables accessible to ALICE in nucleus-nucleus, proton-nucleus and proton-proton collisions. In addition, aspects of specific interest for proton-proton, proton-nucleus, ultraperipheral collisions and cosmic ray physics, which can be addressed by ALICE, are also discussed.

  20. Single-photon pulsed-light indirect time-of-flight 3D ranging.

    PubMed

    Bellisai, S; Bronzi, D; Villa, F A; Tisa, S; Tosi, A; Zappa, F

    2013-02-25

    "Indirect" time-of-flight is one technique to obtain depth-resolved images through active illumination that is becoming more popular in the recent years. Several methods and light timing patterns are used nowadays, aimed at improving measurement precision with smarter algorithms, while using less and less light power. Purpose of this work is to present an indirect time-of-flight imaging camera based on pulsed-light active illumination and a 32 × 32 single-photon avalanche diode array with an improved illumination timing pattern, able to increase depth resolution and to reach single-photon level sensitivity. PMID:23482043

  1. Deconvolution method for recovering the photon time-of-flight distribution from time-resolved measurements.

    PubMed

    Diop, Mamadou; St Lawrence, Keith

    2012-06-15

    A nonparametric deconvolution algorithm for recovering the photon time-of-flight distribution (TOFD) from time-resolved (TR) measurements is described. The algorithm combines wavelet denoising and a two-stage deconvolution method based on generalized singular value decomposition and Tikhonov regularization. The efficacy of the algorithm was tested on simulated and experimental TR data and the results show that it can recover the photon TOFD with high fidelity. Combined with the microscopic Beer-Lambert law, the algorithm enables accurate quantification of absorption changes from arbitrary time-of-flight windows, thereby optimizing the depth sensitivity provided by TR measurements. PMID:22739907

  2. Optimisation of the design parameters of a reflection geometry time-of-flight mass spectrometer

    SciTech Connect

    Sankari, M.; Suryanarayana, M.V.

    1996-12-31

    Optimisation of the design parameters for a reflectron geometry time-of-flight mass spectrometer (RTOFMS) has been done by a simplex optimisation method based on a Nelder-Mead Algorithm. The space and energy resolutions obtained are 6100 and 7400, respectively, for mass 200 amu. The resolution is quite adequate for all the applications of RIMS. A high resolution reflectron geometry time-of-flight mass spectrometer (RTOFMS) for resonance ionisation mass spectrometer (RIMS) is being fabricated, based on these optimised design parameters. 19 refs., 9 figs., 2 tabs.

  3. Time of flight estimation for breast cancer margin thickness using embedded tumors

    NASA Astrophysics Data System (ADS)

    Bowman, Tyler; El-Shenawee, Magda; Campbell, Lucas

    2016-03-01

    This work aims to enact a quick and reasonable estimation of breast cancer margin thickness using time of flight analysis of embedded breast cancer tissue. A pulsed terahertz system is used to obtain reflection imaging scans from breast cancer tumors that are formalin-fixed and embedded in paraffin blocks. Time of flight analysis is then used to compare the reflection patterns seen within the block to pathology sections and paraffin-embedded sections that are taken throughout the depth of the tumor in order to estimate the three-dimensional boundaries of the tumor.

  4. Strangeness detection in ALICE experiment at LHC

    SciTech Connect

    Safarik, K.

    1995-07-15

    The authors present some parameters of the ALICE detector which concern the detection of strange particles. The results of a simulation for neutral strange particles and cascades, together with estimated rates are presented. They also briefly discuss the detection of charged K-mesons. Finally, they mention the possibility of open charm particle detection.

  5. The time-of-flight system on the Goddard medium energy gamma-ray telescope

    NASA Technical Reports Server (NTRS)

    Ross, R. W.; Chesney, J. R.

    1979-01-01

    A scintillation counter time of flight system, incorporated into the Goddard 50 cm by 50 cm spark chamber gamma ray telescope is described. The system, which utilizes constant fractions timing and particle position compensation and digitizes up to 10 ns time differences to six bit accuracy in less than 500 ns is analyzed. The performance of this system during balloon flight is discussed.

  6. Time-of-Flight Measurement of the Speed of Sound in Water

    ERIC Educational Resources Information Center

    Ganci, Salvatore

    2016-01-01

    A simple setup is designed to investigate a "time-of-flight" measurement of the speed of sound in water. This experiment only requires low cost components and is also very simple to understand by students. It could be easily used as a demonstration experiment.

  7. Time-of-Flight Measurement of the Speed of Sound in a Metal Bar

    ERIC Educational Resources Information Center

    Ganci, Salvatore

    2016-01-01

    A simple setup was designed for a "time-of-flight" measurement of the sound speed in a metal bar. The experiment requires low cost components and is very simple to understand by students. A good use of it is as a demonstration experiment.

  8. Incident spectrum determination for time-of-flight neutron powder diffraction data analysis.

    SciTech Connect

    Hodges, J. P.

    1998-08-27

    Accurate characterization of the incident neutron spectrum is an important requirement for precise Rietveld analysis of time-of-flight powder neutron diffraction data. Without an accurate incident spectrum the calculated model for the measured relative intensities of individual Bragg reflections will possess systematic errors. We describe a method for obtaining an accurate numerical incident spectrum using data from a transmitted beam monitor.

  9. Sensitivity Upgrades to the Idaho Accelerator Center Neutron Time of Flight Spectrometer

    SciTech Connect

    Thompson, S. J.; Kinlaw, M. T.; Harmon, J. F.; Wells, D. P.; Hunt, A. W.

    2007-10-26

    Past experiments have shown that discrimination between between fissionable and non-fissionable materials is possible using an interrogation technique that monitors for high energy prompt fission neutrons. Several recent upgrades have been made to the neutron time of flight spectrometer at the Idaho Accelerator Center with the intent of increasing neutron detection sensitivity, allowing for system use in nonproliferation and security applications.

  10. Four-Spot Time-Of-Flight Laser Anemometer For Turbomachinery

    NASA Technical Reports Server (NTRS)

    Wernet, Mark P.; Skoch, Gary J.

    1995-01-01

    Two-color, four-spot time-of-flight laser anemometer designed for measuring flow velocity within narrow confines of small centrifugal compressor. Apparatus well suited for measuring fast (typical speeds 160 to 700 m/s), highly turbulent gas flows in turbomachinery. Other potential applications include measurement of gas flows in pipelines and in flows from explosions.

  11. Identification of Bacteria Using Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry

    ERIC Educational Resources Information Center

    Kedney, Mollie G.; Strunk, Kevin B.; Giaquinto, Lisa M.; Wagner, Jennifer A.; Pollack, Sidney; Patton, Walter A.

    2007-01-01

    Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS or simply MALDI) has become ubiquitous in the identification and analysis of biomacromolecules. As a technique that allows for the molecular weight determination of otherwise nonvolatile molecules, MALDI has had a profound impact in the molecular…

  12. Laser desorption time-of-flight mass spectrometer DNA analyzer. Final report

    SciTech Connect

    Chen, C.H.W.; Martin, S.A.

    1997-02-01

    The objective of this project is the development of a laser desorption time-of-flight mass spectrometer DNA analyzer which can be broadly used for biomedical research. Tasks include: pulsed ion extraction to improve resolution; two-component matrices to enhance ionization; and solid phase DNA purification.

  13. Compensation of the volume charge of ions in a time-of-flight mass analyzer

    NASA Astrophysics Data System (ADS)

    Hashimov, A. M.; Nuruyev, K. Z.; Gurbanov, K. B.; Nurubeyli, Z. K.; Nurubeyli, T. K.

    2007-11-01

    A method of forced compensation of the volume charge of ions leading to considerable deterioration of the dispersion characteristics of a time-of-flight mass analyzer with a sector electrostatic field is described. It is shown that recompensation of the voluem charge also deteriorates the resolution of the instrument.

  14. Proceedings of the 1986 workshop on advanced time-of-flight neutron powder diffraction

    SciTech Connect

    Lawson, A.C.; Smith, K.

    1986-09-01

    This report contains abstracts of talks and summaries of discussions from a small workshop held to discuss the future of time-of-flight neutron powder diffraction and its implementation at the Los Alamos Neutron Scattering Center. 47 refs., 3 figs.

  15. TIME-OF-FLIGHT AEROSOL BEAM SPECTROMETER FOR PARTICLE SIZE MEASUREMENTS

    EPA Science Inventory

    A time-of-flight aerosol beam spectrometer (TOFABS) is described. The instrument has been designed and constructed to perform in situ real time measurements of the aerodynamic size of individual aerosol particles in the range 0.3 to 10 micrometers diameter. The measurement method...

  16. Time-of-flight measurement of the speed of sound in water

    NASA Astrophysics Data System (ADS)

    Ganci, Salvatore

    2016-05-01

    A simple setup is designed to investigate a time-of-flight measurement of the speed of sound in water. This experiment only requires low cost components and is also very simple to understand by students. It could be easily used as a demonstration experiment.

  17. Design Features and Mutual Compatibility Studies of the Time-of-Flight PET Capable GE SIGNA PET/MR System.

    PubMed

    Levin, Craig S; Maramraju, Sri Harsha; Khalighi, Mohammad Mehdi; Deller, Timothy W; Delso, Gaspar; Jansen, Floris

    2016-08-01

    A recent entry into the rapidly evolving field of integrated PET/MR scanners is presented in this paper: a whole body hybrid PET/MR system (SIGNA PET/MR, GE Healthcare) capable of simultaneous acquisition of both time-of-flight (TOF) PET and high resolution MR data. The PET ring was integrated into an existing 3T MR system resulting in a (patient) bore opening of 60 cm diameter, with a 25 cm axial FOV. PET performance was evaluated both on the standalone PET ring and on the same detector integrated into the MR system, to assess the level of mutual interference between both subsystems. In both configurations we obtained detector performance data. PET detector performance was not significantly affected by integration into the MR system. The global energy resolution was within 2% (10.3% versus 10.5%), and the system coincidence time resolution showed a maximum change of < 3% (385 ps versus 394 ps) when measured outside MR and during simultaneous PET/MRI acquisitions, respectively. To evaluate PET image quality and resolution, the NEMA IQ phantom was acquired with MR idle and with MR active. Impact of PET on MR IQ was assessed by comparing SNR with PET acquisition on and off. B0 and B1 homogeneities were acquired before and after the integration of the PET ring inside the magnet. In vivo brain and whole body head-to-thighs data were acquired to demonstrate clinical image quality. PMID:26978664

  18. Optimizing light transport in scintillation crystals for time-of-flight PET: an experimental and optical Monte Carlo simulation study

    PubMed Central

    Berg, Eric; Roncali, Emilie; Cherry, Simon R.

    2015-01-01

    Achieving excellent timing resolution in gamma ray detectors is crucial in several applications such as medical imaging with time-of-flight positron emission tomography (TOF-PET). Although many factors impact the overall system timing resolution, the statistical nature of scintillation light, including photon production and transport in the crystal to the photodetector, is typically the limiting factor for modern scintillation detectors. In this study, we investigated the impact of surface treatment, in particular, roughening select areas of otherwise polished crystals, on light transport and timing resolution. A custom Monte Carlo photon tracking tool was used to gain insight into changes in light collection and timing resolution that were observed experimentally: select roughening configurations increased the light collection up to 25% and improved timing resolution by 15% compared to crystals with all polished surfaces. Simulations showed that partial surface roughening caused a greater number of photons to be reflected towards the photodetector and increased the initial rate of photoelectron production. This study provides a simple method to improve timing resolution and light collection in scintillator-based gamma ray detectors, a topic of high importance in the field of TOF-PET. Additionally, we demonstrated utility of our Monte Carlo simulation tool to accurately predict the effect of altering crystal surfaces on light collection and timing resolution. PMID:26114040

  19. A multichannel time-of-flight system for observation of energetic ions of multispecies generated from relativistic laser plasma

    SciTech Connect

    Matsukado, K.; Fujimoto, M.; Takahashi, H.; Kawada, Y.; Ohsuka, S.; Aoshima, S.

    2010-02-15

    A multichannel time-of-flight (TOF) system was constructed to observe the ions generated from relativistic laser plasma, where the ions have polychromatic energies and multiple species. The TOF system is composed of a ten-channel scintillation detector array and an electromagnet that generates a magnetic field of 0-1.24 T. The magnet field enables us to analyze protons, deuterons, and full-stripped carbon ions to 50, 25, and 150 MeV, respectively. The system experimentally identified protons of 0.27-1.6 MeV energy and ions of a half specific charge (deuterons of 0.3-0.8 MeV and full-stripped carbons of 1.8-4.8 MeV). The measured TOF values agree well with the calculated values within the designed accuracy; {+-}2.5 ns for protons and {+-}5 ns for the others (d or C{sup 6+}) on each detector channel. Comparison of ion numbers detected by a track detector (CR-39) and the TOF system enabled us to obtain the number of ions detected on each scintillation counter with less than 16% error.

  20. Time-of-flight direct recoil spectrometry: Application to liquid surfaces and steps toward quantification

    NASA Astrophysics Data System (ADS)

    Tassotto, Michael

    2001-08-01

    Liquid surfaces are very abundant in nature. Despite the importance of the liquid interface in general, experimental molecular-level data was almost completely lacking prior to the last decade and a half. The intent of this work is to provide a means by which experimental data on the composition of liquid surfaces and the average orientation of their constituent molecules can be obtained in order to supplement data from molecular dynamics and related computational techniques. To this end, a unique time-of-flight (TOF) spectrometer, which constitutes the backbone of a new method to study liquid surfaces, was constructed and commissioned. The performance of the spectrometer is demonstrated in a number of exemplary TOF spectra obtained from liquid glycerol. Moving from mere qualitative to quantitative surface analysis necessitates the ability to relate physical quantities such as detection efficiencies, accurate signal intensities, and interaction cross-sections for all elements to one another. As a first step, the absolute detection efficiency of a channel electron multiplier, used as particle detector in the spectrometer, was measured for the noble gas ions He+, Ar+, and Xe +. The data obtained led to an empirically derived, general expression of the detection efficiency that is applicable to particles of any atomic number. The results also show that the threshold velocity, below which a multiplier does not respond to impinging ions, cannot be regarded as independent of the ion's atomic number as previously reported in the literature. The second step involved a comprehensive investigation of ion-atom interactions and spectral features that are crucial for the processing of experimental signal intensities for quantitative analysis. For this purpose, the binary collision code MARLOWE was used in extensive trajectory calculations simulating TOF spectra. The simulation results confirm the high surface sensitivity of the technique and reveal the strong dependence of the

  1. Imaging objects behind a partially reflective surface with a modified time-of-flight sensor

    NASA Astrophysics Data System (ADS)

    Geerardyn, D.; Kuijk, M.

    2014-05-01

    Time-of-Flight (ToF) methods are used in different applications for depth measurements. There are mainly 2 types of ToF measurements, Pulsed Time-of-Flight and Continuous-Wave Time-of-Flight. Pulsed Time-of-Flight (PToF) techniques are mostly used in combination with a scanning mirror, which makes them not well suited for imaging purposes. Continuous-wave Time-of-Flight (CWToF) techniques are mostly used wide-field, hence they are much faster and more suited for imaging purposes but cannot be used behind partially-reflective surfaces. In commercial applications, both ToF methods require specific hardware, which cannot be exchanged. In this paper, we discuss the transformation of a CWToF sensor to a PToF camera, which is able to make images and measure the distances of objects behind a partially-reflective surface, like the air-water interface in swimming pools when looking from above. We first created our own depth camera which is suitable for both CWToF and PToF. We describe the necessary hardware components for a normal ToF camera and compare it with the adapted components which make it a range-gating depth imager. Afterwards, we modeled the distances and images of one or more objects positioned behind a partially-reflective surface and combine it with measurement data of the optical pulse. A scene was virtualized and the rays from a raytracing software tool were exported to Matlab™. Subsequently, pulse deformations were calculated for every pixel, which resulted in the calculation of the depth information.

  2. ALICE moves into warp drive

    NASA Astrophysics Data System (ADS)

    Carena, F.; Carena, W.; Chapeland, S.; Chibante Barroso, V.; Costa, F.; Dénes, E.; Divià, R.; Fuchs, U.; Grigore, A.; Simonetti, G.; Soós, C.; Telesca, A.; Vande Vyvre, P.; von Haller, B.

    2012-12-01

    A Large Ion Collider Experiment (ALICE) is the heavy-ion detector designed to study the physics of strongly interacting matter and the quark-gluon plasma at the CERN Large Hadron Collider (LHC). Since its successful start-up in 2010, the LHC has been performing outstandingly, providing to the experiments long periods of stable collisions and an integrated luminosity that greatly exceeds the planned targets. To fully explore these privileged conditions, we aim at maximizing the experiment's data taking productivity during stable collisions. We present in this paper the evolution of the online systems towards helping us understand reasons of inefficiency and address new requirements. This paper describes the features added to the ALICE Electronic Logbook (eLogbook) to allow the Run Coordination team to identify, prioritize, fix and follow causes of inefficiency in the experiment. Thorough monitoring of the data taking efficiency provides reports for the collaboration to portray its evolution and evaluate the measures (fixes and new features) taken to increase it. In particular, the eLogbook helps decision making by providing quantitative input, which can be used to better balance risks of changes in the production environment against potential gains in quantity and quality of physics data. It will also present the evolution of the Experiment Control System (ECS) to allow on-the-fly error recovery actions of the detector apparatus while limiting as much as possible the loss of integrated luminosity. The paper will conclude with a review of the ALICE efficiency so far and the future plans to improve its monitoring.

  3. ALICE: Physics Performance Report, Volume II

    NASA Astrophysics Data System (ADS)

    ALICE Collaboration; Alessandro, B.; Antinori, F.; Belikov, J. A.; Blume, C.; Dainese, A.; Foka, P.; Giubellino, P.; Hippolyte, B.; Kuhn, C.; Martínez, G.; Monteno, M.; Morsch, A.; Nayak, T. K.; Nystrand, J.; López Noriega, M.; Paic, G.; Pluta, J.; Ramello, L.; Revol, J.-P.; Safarík, K.; Schukraft, J.; Schutz, Y.; Scomparin, E.; Snellings, R.; Villalobos Baillie, O.; Vercellin, E.

    2006-09-01

    ALICE is a general-purpose heavy-ion experiment designed to study the physics of strongly interacting matter and the quark gluon plasma in nucleus nucleus collisions at the LHC. It currently involves more than 900 physicists and senior engineers, from both the nuclear and high-energy physics sectors, from over 90 institutions in about 30 countries. The ALICE detector is designed to cope with the highest particle multiplicities above those anticipated for Pb Pb collisions (dNch/dy up to 8000) and it will be operational at the start-up of the LHC. In addition to heavy systems, the ALICE Collaboration will study collisions of lower-mass ions, which are a means of varying the energy density, and protons (both pp and pA), which primarily provide reference data for the nucleus nucleus collisions. In addition, the pp data will allow for a number of genuine pp physics studies. The detailed design of the different detector systems has been laid down in a number of Technical Design Reports issued between mid-1998 and the end of 2004. The experiment is currently under construction and will be ready for data taking with both proton and heavy-ion beams at the start-up of the LHC. Since the comprehensive information on detector and physics performance was last published in the ALICE Technical Proposal in 1996, the detector, as well as simulation, reconstruction and analysis software have undergone significant development. The Physics Performance Report (PPR) provides an updated and comprehensive summary of the performance of the various ALICE subsystems, including updates to the Technical Design Reports, as appropriate. The PPR is divided into two volumes. Volume I, published in 2004 (CERN/LHCC 2003-049, ALICE Collaboration 2004 J. Phys. G: Nucl. Part. Phys. 30 1517 1763), contains in four chapters a short theoretical overview and an extensive reference list concerning the physics topics of interest to ALICE, the experimental conditions at the LHC, a short summary and update of

  4. Measuring time of flight of fusion products in an inertial electrostatic confinement fusion device for spatial profiling of fusion reactions

    NASA Astrophysics Data System (ADS)

    Donovan, D. C.; Boris, D. R.; Kulcinski, G. L.; Santarius, J. F.; Piefer, G. R.

    2013-03-01

    A new diagnostic has been developed that uses the time of flight (TOF) of the products from a nuclear fusion reaction to determine the location where the fusion reaction occurred. The TOF diagnostic uses charged particle detectors on opposing sides of the inertial electrostatic confinement (IEC) device that are coupled to high resolution timing electronics to measure the spatial profile of fusion reactions occurring between the two charged particle detectors. This diagnostic was constructed and tested by the University of Wisconsin-Madison Inertial Electrostatic Confinement Fusion Group in the IEC device, HOMER, which accelerates deuterium ions to fusion relevant energies in a high voltage (˜100 kV), spherically symmetric, electrostatic potential well [J. F. Santarius, G. L. Kulcinski, R. P. Ashley, D. R. Boris, B. B. Cipiti, S. K. Murali, G. R. Piefer, R. F. Radel, T. E. Radel, and A. L. Wehmeyer, Fusion Sci. Technol. 47, 1238 (2005)]. The TOF diagnostic detects the products of D(d,p)T reactions and determines where along a chord through the device the fusion event occurred. The diagnostic is also capable of using charged particle spectroscopy to determine the Doppler shift imparted to the fusion products by the center of mass energy of the fusion reactants. The TOF diagnostic is thus able to collect spatial profiles of the fusion reaction density along a chord through the device, coupled with the center of mass energy of the reactions occurring at each location. This provides levels of diagnostic detail never before achieved on an IEC device.

  5. Towards arrays of smart-pixels for time-correlated single photon counting and time of flight application

    NASA Astrophysics Data System (ADS)

    Markovic, Bojan; Tisa, Simone; Tosi, Alberto; Zappa, Franco

    2011-01-01

    We present a novel "smart-pixel" able to detect single photons and to measure and record in-pixel the time delay between a START pulse (e.g., laser excitation, cell stimulus, or LIDAR flash) and a STOP pulse given by the detection of a single photon (e. g., fluorescence decay signal or back reflection from an object). This smart-pixel represents the basic building block of SPAD arrays aimed at time-correlated single photon counting (TCSPC) applications (like FLIM, FCS, FRET), but also at photon timing and direct Time-of-Flight (dTOF) measurements for 3D ranging applications (e.g., in LIDAR systems). The pixel comprises a Single-Photon Avalanche Diode (SPAD) detector, an analog sensing and driving electronics, and a Time-to-Digital Converter monolithically designed and manufactured into the same chip. We report on the design and characterization of prototype circuits, fabricated in a 0.35 μm standard CMOS technology containing complete conversion channels, smart-pixels and ancillary electronics with 20 μm active area diameter SPAD detectors and related quenching circuitry. With a 100 MHz reference clock, the TDC provides a time-resolution of 10 ps, a dynamic range of 160 ns and very high conversion linearity.

  6. Measuring time of flight of fusion products in an inertial electrostatic confinement fusion device for spatial profiling of fusion reactions

    SciTech Connect

    Donovan, D. C.; Boris, D. R.; Kulcinski, G. L.; Santarius, J. F.; Piefer, G. R.

    2013-03-15

    A new diagnostic has been developed that uses the time of flight (TOF) of the products from a nuclear fusion reaction to determine the location where the fusion reaction occurred. The TOF diagnostic uses charged particle detectors on opposing sides of the inertial electrostatic confinement (IEC) device that are coupled to high resolution timing electronics to measure the spatial profile of fusion reactions occurring between the two charged particle detectors. This diagnostic was constructed and tested by the University of Wisconsin-Madison Inertial Electrostatic Confinement Fusion Group in the IEC device, HOMER, which accelerates deuterium ions to fusion relevant energies in a high voltage ({approx}100 kV), spherically symmetric, electrostatic potential well [J. F. Santarius, G. L. Kulcinski, R. P. Ashley, D. R. Boris, B. B. Cipiti, S. K. Murali, G. R. Piefer, R. F. Radel, T. E. Radel, and A. L. Wehmeyer, Fusion Sci. Technol. 47, 1238 (2005)]. The TOF diagnostic detects the products of D(d,p)T reactions and determines where along a chord through the device the fusion event occurred. The diagnostic is also capable of using charged particle spectroscopy to determine the Doppler shift imparted to the fusion products by the center of mass energy of the fusion reactants. The TOF diagnostic is thus able to collect spatial profiles of the fusion reaction density along a chord through the device, coupled with the center of mass energy of the reactions occurring at each location. This provides levels of diagnostic detail never before achieved on an IEC device.

  7. Ambient aerosol analysis using aerosol-time-of-flight mass spectrometry

    SciTech Connect

    Prather, K.A.; Noble, C.A.; Liu, D.Y.; Silva, P.J.; Fergenson, D.F.

    1996-10-01

    We have recently developed a technique, Aerosol-Time-of-Flight Mass Spectrometry (ATOFMS), which is capable of real-time determination of the aerodynamic size and chemical composition of individual aerosol particles. In order to obtain such information, the techniques of aerodynamic particle sizing and time-of-flight mass spectrometry are combined in a single instrument. ATOFMS is being used for the direct analysis of ambient aerosols with the goal of establishing correlations between particle size and chemical composition. Currently, measurements are being made to establish potential links between the presence of particular types of particles with such factors as the time of day, weather conditions, and concentration levels of gaseous smog components such as NO{sub x} and ozone. This data will be used to help establish a better understanding of tropospheric gas-aerosol processes. This talk will discuss the operating principles of ATOFMS as well as present the results of ambient analysis studies performed in our laboratory.

  8. A compact time-of-flight mass spectrometer for ion source characterization.

    PubMed

    Chen, L; Wan, X; Jin, D Z; Tan, X H; Huang, Z X; Tan, G B

    2015-03-01

    A compact time-of-flight mass spectrometer with overall dimension of about 413 × 250 × 414 mm based on orthogonal injection and angle reflection has been developed for ion source characterization. Configuration and principle of the time-of-flight mass spectrometer are introduced in this paper. The mass resolution is optimized to be about 1690 (FWHM), and the ion energy detection range is tested to be between about 3 and 163 eV with the help of electron impact ion source. High mass resolution and compact configuration make this spectrometer useful to provide a valuable diagnostic for ion spectra fundamental research and study the mass to charge composition of plasma with wide range of parameters. PMID:25832275

  9. Invited Article: Characterization of background sources in space-based time-of-flight mass spectrometers

    SciTech Connect

    Gilbert, J. A.; Gershman, D. J.; Gloeckler, G.; Lundgren, R. A.; Zurbuchen, T. H.; Orlando, T. M.; McLain, J.; Steiger, R. von

    2014-09-15

    For instruments that use time-of-flight techniques to measure space plasma, there are common sources of background signals that evidence themselves in the data. The background from these sources may increase the complexity of data analysis and reduce the signal-to-noise response of the instrument, thereby diminishing the science value or usefulness of the data. This paper reviews several sources of background commonly found in time-of-flight mass spectrometers and illustrates their effect in actual data using examples from ACE-SWICS and MESSENGER-FIPS. Sources include penetrating particles and radiation, UV photons, energy straggling and angular scattering, electron stimulated desorption of ions, ion-induced electron emission, accidental coincidence events, and noise signatures from instrument electronics. Data signatures of these sources are shown, as well as mitigation strategies and design considerations for future instruments.

  10. A compact time-of-flight mass spectrometer for ion source characterization

    SciTech Connect

    Chen, L. Wan, X.; Jin, D. Z.; Tan, X. H.; Huang, Z. X.; Tan, G. B.

    2015-03-15

    A compact time-of-flight mass spectrometer with overall dimension of about 413 × 250 × 414 mm based on orthogonal injection and angle reflection has been developed for ion source characterization. Configuration and principle of the time-of-flight mass spectrometer are introduced in this paper. The mass resolution is optimized to be about 1690 (FWHM), and the ion energy detection range is tested to be between about 3 and 163 eV with the help of electron impact ion source. High mass resolution and compact configuration make this spectrometer useful to provide a valuable diagnostic for ion spectra fundamental research and study the mass to charge composition of plasma with wide range of parameters.

  11. New Converging Collimator for Cold Neutrons Time-Of-Flight Measurements

    NASA Astrophysics Data System (ADS)

    Naguib, K.; Sallam, O. H.; Salama, Mohamed

    An idea to design a new converging collimator for cold neutron time-of-flight measurements is presented. Using this new facility in combination with a neutron time-of-flight spectrometer, we may have neutron intensity gain factors about three times that obtained using the conventional straight slit collimators. Expressions for calculating the collimators dimensions as well as the intensity gain and the time resolution broading were presented.Translated AbstractEin neuer, konvergierender Kollimator für Flugzeitmessungen mit langsamen NeutronenDie Idee der Konstruktion eines neuen, konvergierenden Kollimators für Flugzeitmessungen mit langsamen Neutronen wird vorgestellt. Mit diesem neuen Gerät in Kombination mit einem Neutronenflugzeitspektrometer sollte sich ein Intensitätsgewinn von drei gegenüber konventionellen Anordnungen ergeben. Die Kollimatordimensionen, der Intensitätsgewinn und die Verbreiterung der Zeitauflösung werden berechnet.

  12. Speciation of arsenic oxides using laser desorption/ionization time-of-flight mass spectrometry.

    PubMed

    Allen, T M; Bezabeh, D Z; Smith, C H; McCauley, E M; Jones, A D; Chang, D P; Kennedy, I M; Kelly, P B

    1996-11-15

    Positive and negative ion mass spectra of arsenic trioxide (As2O3) and arsenic pentaoxide (As2O5) have been obtained by single-step laser desorption/ionization time-of-flight mass spectrometry. Pulsed UV radiation at 266 nm was used for the simultaneous desorption and ionization of the solid sample. High-mass cluster ions that are unique to the oxidation state of each oxide sample appear in the negative ion mass spectra. The As2O3 produces As3O5-, while the As2O5 yields As3O8-. The formation of unique negative cluster ions presents the capability for arsenic oxidation state speciation by laser desorption/ionization mass spectrometry. The ability of time-of-flight mass spectrometry to examine the relative amounts of each arsenic oxide present in a series of mixtures is discussed. Application of our speciation technique to a model incinerator sample is demonstrated. PMID:8916457

  13. Rietveld refinement with time-of-flight powder diffraction data from pulsed neutron sources

    SciTech Connect

    David, W.I.F. ); Jorgensen, J.D. )

    1990-10-01

    The recent development of accelerator-based pulsed neutron sources has led to the widespread use of the time-of-flight technique for neutron powder diffraction. The properties of the pulsed source make possible unusually high resolution over a wide range of d spacings, high count rates, and the ability to collect complete data at fixed scattering angles. The peak shape and other instrument characteristics can be accurately modelled, which make Rietveld refinement possible for complex structures. In this paper we briefly review the development of the Rietveld method for time-of-flight diffraction data from pulsed neutron sources and discuss the latest developments in high resolution instrumentation and advanced Rietveld analysis methods. 50 refs., 12 figs., 14 tabs.

  14. Beam derived trigger system for multibunch time-of-flight measurement

    SciTech Connect

    Fox, J.; Pellegrin, J.L.

    1981-01-01

    Particle time-of-flight measurement requires accurate triggers in synchronism with each bunch, and occurring in a sequence which depends on the position of the observer around the storage ring. A system has been devised for tagging the colliding bunches at each interaction point; it allows one to record which pair of bunches is colliding at any time and any location around the machine. Besides bunch identification, the time-of-flight triggers are also expected to have a time stability better than the bunch length itself. A system is presented here which exhibits time variations of less than 80 psec over a 20 to 1 range of beam current, while the jitter is at least an order of magnitude smaller. 4 refs., 4 figs.

  15. Study of ultrasonic thermometry based on ultrasonic time-of-flight measurement

    NASA Astrophysics Data System (ADS)

    Jia, Ruixi; Xiong, Qingyu; Wang, Lijie; Wang, Kai; Shen, Xuehua; Liang, Shan; Shi, Xin

    2016-03-01

    Ultrasonic thermometry is a kind of acoustic pyrometry and it has been evolving as a new temperature measurement technology for various environment. However, the accurate measurement of the ultrasonic time-of-flight is the key for ultrasonic thermometry. In this paper, we study the ultrasonic thermometry technique based on ultrasonic time-of-flight measurement with a pair of ultrasonic transducers for transmitting and receiving signal. The ultrasonic transducers are installed in a single path which ultrasonic travels. In order to validate the performance of ultrasonic thermometry, we make a contrast about the absolute error between the measured temperature value and the practical one. With and without heater source, the experimental results indicate ultrasonic thermometry has high precision of temperature measurement.

  16. Near-infrared photon time-of-flight spectroscopy of turbid materials up to 1400 nm.

    PubMed

    Svensson, Tomas; Alerstam, Erik; Khoptyar, Dmitry; Johansson, Jonas; Folestad, Staffan; Andersson-Engels, Stefan

    2009-06-01

    Photon time-of-flight spectroscopy (PTOFS) is a powerful tool for analysis of turbid materials. We have constructed a time-of-flight spectrometer based on a supercontinuum fiber laser, acousto-optical tunable filtering, and an InP/InGaAsP microchannel plate photomultiplier tube. The system is capable of performing PTOFS up to 1400 nm, and thus covers an important region for vibrational spectroscopy of solid samples. The development significantly increases the applicability of PTOFS for analysis of chemical content and physical properties of turbid media. The great value of the proposed approach is illustrated by revealing the distinct absorption features of turbid epoxy resin. Promising future applications of the approach are discussed, including quantitative assessment of pharmaceuticals, powder analysis, and calibration-free near-infrared spectroscopy. PMID:19566194

  17. Neutron-induced fission measurements at the time-of-flight facility nELBE

    DOE PAGESBeta

    Kögler, T.; Beyer, R.; Junghans, A. R.; Massarczyk, R.; Schwengner, R.; Wagner, A.

    2015-05-18

    Neutron-induced fission of ²⁴²Pu is studied at the photoneutron source nELBE. The relative fast neutron fission cross section was determined using actinide fission chambers in a time-of-flight experiment. A good agreement of present nuclear data with evalua- tions has been achieved in the range of 100 keV to 10 MeV.

  18. Protein mixture analysis by MALDI/mobility/time-of-flight mass spectrometry

    NASA Astrophysics Data System (ADS)

    Russell, David H.; Gillig, Kent J.; Stone, Earle; Park, Zee-Yong; Fuhrer, K.; Gonon, M.; Schultz, A. J.

    2000-03-01

    Progress in the development of ion mobility (IM) orthogonal time-of-flight (oTOF) mass spectrometry for rapid analysis of biological samples is presented. The IM-oTOF apparatus described consists of a short drift tube (1 to 15 cm) designed for ion mobility measurement in the low-field limit and a low resolution linear (20 cm) TOF mass spectrometer. Proof of concept is demonstrated by analysis of peptide mixtures generated by proteolytic digestion of proteins.

  19. Fully digital data acquisition system for the neutron time-of-flight spectrometer TOFOR at JET

    SciTech Connect

    Skiba, M.; Weiszflog, M.; Hjalmarsson, A.; Ericsson, G.; Hellesen, C.; Conroy, S.; Andersson-Sunden, E.; Eriksson, J.; Binda, F.; Collaboration: JET-EFDA Contributors

    2012-10-15

    A prototype of a fully digital data acquisition system based on 1 Gsps 12 bit digitizers for the TOFOR fusion neutron spectrometer at JET is assessed. The prototype system enables the use of geometry-based background discrimination techniques, which are modeled, evaluated, and compared to experimental data. The experimental results are in line with the models and show a significant improvement in signal-to-background ratio in measured time-of-flight spectrum compared to the existing data acquisition system.

  20. Semen quality detection using time of flight and acoustic wave sensors

    NASA Astrophysics Data System (ADS)

    Newton, M. I.; Evans, C. R.; Simons, J. J.; Hughes, D. C.

    2007-04-01

    The authors report a real-time technique for assessing the number of motile sperm in a semen sample. The time of flight technique uses a flow channel with detection at the end of the channel using quartz crystal microbalances. Data presented suggest that a simple rigid mass model may be used in interpreting the change in resonant frequency using an effective mass for the sperm.

  1. The time-of-flight spectrometer with cold neutrons at the FRM-II

    NASA Astrophysics Data System (ADS)

    Zirkel, A.; Roth, S.; Schneider, W.; Neuhaus, J.; Petry, W.

    2000-03-01

    We are presenting a design study of the new cold-time-of-flight spectrometer to be built at the FRM-II. Monte Carlo techniques were used to optimize the flux at the sample position and to calculate the elastic energy resolution. A doubly focusing neutron guide is used to enhance the intensity on the sample. Magnetic bearings and carbon fiber composite disks will give access to very high chopper speeds, thereby considerably increasing the overall performance of the instrument.

  2. Contactless flow measurement in liquid metal using electromagnetic time-of-flight method

    NASA Astrophysics Data System (ADS)

    Dubovikova, Nataliia; Resagk, Christian; Karcher, Christian; Kolesnikov, Yuri

    2016-05-01

    Measuring flow rates of liquid metal flows is of utmost importance in industrial applications such as metal casting, in order to ensure process efficiency and product quality. A non-contact method for flow rate control is described here. The method is known as time-of-flight Lorentz force velocimetry (LFV) and determines flow rate through measurement of Lorentz force that act on magnet systems that are placed close to the flow. In this method, a vortex generator is used to generate an eddy in the flow, with two magnet systems separated by a known distance placed downstream of the vortex generator. Each of the magnet systems has a force sensor attached to them which detects the passing of the eddy through its magnetic field as a significant perturbation in the force signal. The flow rate is estimated from the time span between the perturbations in the two force signals. In this paper, time-of-flight LFV technique is demonstrated experimentally for the case of liquid metal flow in a closed rectangular duct loop that is driven by an electromagnetic pump. A liquid metal alloy of gallium (Ga), indium (In) and tin (Sn)—GaInSn—is used as the working fluid. In contrast to prior works, for the first time, three-dimensional strain gauge force sensors were used for measuring Lorentz force to investigate the effect of flow disturbances in different directions for flow measurements by the time-of-flight LFV method. A prototype time-of-flight LFV flowmeter is developed, the operation of which in laboratory conditions is characterised by different experiments.

  3. Semen quality detection using time of flight and acoustic wave sensors

    SciTech Connect

    Newton, M. I.; Evans, C. R.; Simons, J. J.; Hughes, D. C.

    2007-04-09

    The authors report a real-time technique for assessing the number of motile sperm in a semen sample. The time of flight technique uses a flow channel with detection at the end of the channel using quartz crystal microbalances. Data presented suggest that a simple rigid mass model may be used in interpreting the change in resonant frequency using an effective mass for the sperm.

  4. [Time of flight mass spectrometry of DNA for rapid sequence determination

    SciTech Connect

    Not Available

    1992-01-01

    The objective of this project is to develop a time-of-flight mass spectrometric approach to ordering Sanger sequence fragments, replacing electrophoresis and removing the electrophoresis bottleneck to rapid DNA sequencing, When the project was funded, we had demonstrated that massive DNA molecules could be volatilized, substantially intact, by a process involving pulsed laser ablation of a frozen film of a DNA solution. Using a crude time-of-flight mass spectrometer, we had demonstrated that ions of the ablated DNA could be formed, and that mass spectra were obtainable which appeared to contain only the parent molecular ion. The laser used was a dye laser which we tuned to match sodium atom resonances to increase the ionization efficiency. By pulsed laser ablation of frozen aqueous DNA solution films we have produced mass spectra of DNA mixtures which largely fulfil the simple requirement for DNA mixture analysis: one peak per DNA segment The peaks are clean and free of the fragment or adduct tails which characteristically degrade mass spectra obtained by UV laser ablation using UV chromophore matrices. To date, our approach has been characterized by extremely poor reproducibility; however the high quality of the mass spectra suggest that when better control of the ionization process is achieved, the use of an aqueous matrix offers an extremely promising approach to time-of-flight mass spectrometric sorting of DNA sequence mixtures.

  5. Accurate time-of-flight measurement of particle based on ECL-TTL Timer

    NASA Astrophysics Data System (ADS)

    Li, Deping; Liu, Jianguo; Huang, Shuhua; Gui, Huaqiao; Cheng, Yin; Wang, Jie; Lu, Yihuai

    2014-11-01

    Because of its aerodynamic diameter of the aerosol particles are stranded in different parts of different human respiratory system, thus affecting human health. Therefore, how to continue to effectively monitor the aerosol particles become increasingly concerned about. Use flight time of aerosol particle beam spectroscopy of atmospheric aerosol particle size distribution is the typical method for monitoring atmospheric aerosol particle size and particle concentration measurement , and it is the key point to accurate measurement of aerosol particle size spectra that measurement of aerosol particle flight time. In order to achieve accurate measurements of aerosol particles in time-of-flight, this paper design an ECL-TTL high-speed timer with ECL counter and TTL counter. The high-speed timer includes a clock generation, high-speed timer and the control module. Clock Generation Module using a crystal plus multiplier design ideas, take advantage of the stability of the crystal to provide a stable 500MHz clock signal is high counter. High count module design using ECL and TTL counter mix design, timing accuracy while effectively maintaining , expanding the timing range, and simplifies circuit design . High-speed counter control module controls high-speed counter start, stop and reset timely based on aerosol particles time-of-flight, is a key part of the high-speed counting. The high-speed counting resolution of 4ns, the full scale of 4096ns, has been successfully applied Aerodynamic Particle Sizer, to meet the precise measurement of aerosol particles time-of-flight.

  6. Nanometer scale elemental analysis in the helium ion microscope using time of flight spectrometry.

    PubMed

    Klingner, N; Heller, R; Hlawacek, G; von Borany, J; Notte, J; Huang, J; Facsko, S

    2016-03-01

    Time of flight backscattering spectrometry (ToF-BS) was successfully implemented in a helium ion microscope (HIM). Its integration introduces the ability to perform laterally resolved elemental analysis as well as elemental depth profiling on the nm scale. A lateral resolution of ≤54nm and a time resolution of Δt≤17ns(Δt/t≤5.4%) are achieved. By using the energy of the backscattered particles for contrast generation, we introduce a new imaging method to the HIM allowing direct elemental mapping as well as local spectrometry. In addition laterally resolved time of flight secondary ion mass spectrometry (ToF-SIMS) can be performed with the same setup. Time of flight is implemented by pulsing the primary ion beam. This is achieved in a cost effective and minimal invasive way that does not influence the high resolution capabilities of the microscope when operating in standard secondary electron (SE) imaging mode. This technique can thus be easily adapted to existing devices. The particular implementation of ToF-BS and ToF-SIMS techniques are described, results are presented and advantages, difficulties and limitations of this new techniques are discussed. PMID:26725148

  7. Acetazolamide challenge for three-dimensional time-of-flight MR angiography of the brain

    SciTech Connect

    Mandai, Kenji; Sueyoshi, Kenji; Fukunaga, Ryuzo; Nukada, Masaru; Ohtani, Fumio; Araki, Yutaka; Tsukaguchi, Isao; Abe, Hiroshi )

    1994-04-01

    We compared three-dimensional time-of-flight MR angiograms obtained before and after acetazolamide administration to evaluate whether use of this drug could improve visualization of small peripheral intracranial arteries and atherosclerotic stenosis. For evaluation of small peripheral arteries, 10 patients with clinical diagnosis of ischemic cerebrovascular disease and 10 healthy volunteers were investigated, and for evaluation of stenosis, another 6 patients were investigated. Vascular images were obtained by three-dimensional time-of-flight MR angiography. After a baseline scan, 17 mg/kg acetazolamide was injected intravenously and the second scan was performed 20 minutes later. Several small peripheral arteries that had not been seen on the baseline images were visible on the acetazolamide images without any augmentation of the background signals. Stenotic lesions in the main trunks of the major cerebral arteries were detected more clearly on acetazolamide images. Acetazolamide improves visualization of small peripheral intracranial arteries and sensitivity in detecting atherosclerotic stenosis in the main trunk of major cerebral artery by three-dimensional time-of-flight MR angiography without changing MR apparatus and software. 15 refs., 5 figs., 2 tabs.

  8. Alice Occultation - Gladstone

    NASA Video Gallery

    This animation shows how the count rate observed by New Horizons’ Alice instrument decreases as Pluto’s atmosphere passes in front of the sun. The decreasing count rate is due to the ultraviolet s...

  9. First Proton-Proton Collisions at the LHC as Observed with the ALICE Detector: Measurement of the Charged Particle Pseudorapidity Density at s = 900 GeV

    SciTech Connect

    Aamodt, K.; Awes, Terry C; Enokizono, Akitomo; Read Jr, Kenneth F; Silvermyr, David O; Collaboration, The ALICE

    2010-01-01

    On 23rd November 2009, during the early commissioning of the CERN Large Hadron Collider (LHC), two counter-rotating proton bunches were circulated for the first time concurrently in the machine, at the LHC injection energy of 450 GeV per beam. Although the proton intensity was very low, with only one pilot bunch per beam, and no systematic attempt was made to optimize the collision optics, all LHC experiments reported a number of collision candidates. In the ALICE experiment, the collision region was centred very well in both the longitudinal and transverse directions and 284 events were recorded in coincidence with the two passing proton bunches. The events were immediately reconstructed and analyzed both online and offline. We have used these events to measure the pseudorapidity density of charged primary particles in the central region. In the range |{eta}|<0.5, we obtain dN{sub ch}/d{eta} = 3.10 {+-} 0.13(stat.) {+-} 0.22(syst.) for all inelastic interactions, and dN{sub ch}/d{eta} = 3.51 {+-} 0.15(stat.) {+-} 0.25(syst.) for non-single diffractive interactions. These results are consistent with previous measurements in proton-antiproton interactions at the same centre-of-mass energy at the CERN Sp {bar p} S collider. They also illustrate the excellent functioning and rapid progress of the LHC accelerator, and of both the hardware and software of the ALICE experiment, in this early start-up phase.

  10. Performance of the ALICE experiment at the CERN LHC

    NASA Astrophysics Data System (ADS)

    Alice Collaboration

    2014-09-01

    ALICE is the heavy-ion experiment at the CERN Large Hadron Collider. The experiment continuously took data during the first physics campaign of the machine from fall 2009 until early 2013, using proton and lead-ion beams. In this paper we describe the running environment and the data handling procedures, and discuss the performance of the ALICE detectors and analysis methods for various physics observables.

  11. ALICE: Physics Performance Report, Volume I

    NASA Astrophysics Data System (ADS)

    ALICE Collaboration; Carminati, F.; Foka, P.; Giubellino, P.; Morsch, A.; Paic, G.; Revol, J.-P.; Safarík, K.; Schutz, Y.; Wiedemann, U. A.

    2004-11-01

    ALICE is a general-purpose heavy-ion experiment designed to study the physics of strongly interacting matter and the quark-gluon plasma in nucleus-nucleus collisions at the LHC. It currently includes more than 900 physicists and senior engineers, from both nuclear and high-energy physics, from about 80 institutions in 28 countries. The experiment was approved in February 1997. The detailed design of the different detector systems has been laid down in a number of Technical Design Reports issued between mid-1998 and the end of 2001 and construction has started for most detectors. Since the last comprehensive information on detector and physics performance was published in the ALICE Technical Proposal in 1996, the detector as well as simulation, reconstruction and analysis software have undergone significant development. The Physics Performance Report (PPR) will give an updated and comprehensive summary of the current status and performance of the various ALICE subsystems, including updates to the Technical Design Reports, where appropriate, as well as a description of systems which have not been published in a Technical Design Report. The PPR will be published in two volumes. The current Volume I contains: a short theoretical overview and an extensive reference list concerning the physics topics of interest to ALICE, relevant experimental conditions at the LHC, a short summary and update of the subsystem designs, and a description of the offline framework and Monte Carlo generators. Volume II, which will be published separately, will contain detailed simulations of combined detector performance, event reconstruction, and analysis of a representative sample of relevant physics observables from global event characteristics to hard processes.

  12. Auxiliary probe design adaptable to existing probes for remote detection NMR, MRI, and time-of-flight tracing.

    PubMed

    Han, Songi; Granwehr, Josef; Garcia, Sandra; McDonnell, Erin E; Pines, Alexander

    2006-10-01

    A versatile, detection-only probe design is presented that can be adapted to any existing NMR or MRI probe with the purpose of making the remote detection concept generally applicable. Remote detection suggests freeing the NMR experiment from the confinement of using the same radio frequency (RF) coil and magnetic field for both information encoding and signal detection. Information is stored during the encoding step onto a fluid sensor medium whose magnetization is later measured in a different location. The choice of an RF probe and magnetic field for encoding can be made based solely on the size and characteristics of the sample and the desired information quality without considering detection sensitivity, as this aspect is dealt with by a separate detector. While early experiments required building probes that included two resonant circuits, one for encoding and one for detection, a modular approach with a detection-only probe as presented here can be used along with any existing NMR probe of choice for encoding. The design of two different detection-only probes is presented, one with a saddle coil for milliliter-sized detection volumes, and the other one with a microsolenoid coil for sub-microliter fluid quantities. As example applications, we present time-of-flight (TOF) tracing of hyperpolarized (129)Xe spins in a gas mixture through coiled tubing using the microsolenoid coil detector and TOF flow imaging through a nested glass container where the gas flow changes its direction twice between inlet and outlet using the saddle coil detector. PMID:16875855

  13. A generalized deconvolution algorithm for image reconstruction in positron emission tomography with time-of-flight information (TOFPET)

    SciTech Connect

    Chen, C.T.; Metz, C.E.

    1984-01-01

    Positron emission tomographic systems capable of time-of-flight measurements open new avenues for image reconstruction. Three algorithms have been proposed previously: the most-likely position method (MLP), the confidence weighting method (CW) and the estimated posterior-density weighting method (EPDW). While MLP suffers from poorer noise properties, both CW and EPDW require substantially more computer processing time. Mathematically, the TOFPET image data at any projection angle represents a 2D image blurred by different TOF and detector spatial resolutions in two perpendicular directions. The integration of TOFPET images over all angles produces a preprocessed 2D image which is the convolution of the true image and a rotationally symmetric point spread function (PSF). Hence the tomographic reconstruction problem for TOFPET can be viewed as nothing more than a 2D image processing task to compensate for a known PSF. A new algorithm based on a generalized iterative deconvolution method and its equivalent filters (''Metz filters'') developed earlier for conventional nuclear medicine image processing is proposed for this purpose. The algorithm can be carried out in a single step by an equivalent filter in the frequency domain; therefore, much of the computation time necessary for CW and EPDW is avoided. Results from computer simulation studies show that this new approach provides excellent resolution enhancement at low frequencies, good noise suppression at high frequencies, a reduction of Gibbs' phenomenon due to sharp filter cutoff, and better quantitative measurements than other methods.

  14. First spatial separation of a heavy ion isomeric beam with a multiple-reflection time-of-flight mass spectrometer

    NASA Astrophysics Data System (ADS)

    Dickel, T.; Plaß, W. R.; Ayet San Andres, S.; Ebert, J.; Geissel, H.; Haettner, E.; Hornung, C.; Miskun, I.; Pietri, S.; Purushothaman, S.; Reiter, M. P.; Rink, A.-K.; Scheidenberger, C.; Weick, H.; Dendooven, P.; Diwisch, M.; Greiner, F.; Heiße, F.; Knöbel, R.; Lippert, W.; Moore, I. D.; Pohjalainen, I.; Prochazka, A.; Ranjan, M.; Takechi, M.; Winfield, J. S.; Xu, X.

    2015-05-01

    211Po ions in the ground and isomeric states were produced via 238U projectile fragmentation at 1000 MeV/u. The 211Po ions were spatially separated in flight from the primary beam and other reaction products by the fragment separator FRS. The ions were energy-bunched, slowed-down and thermalized in a gas-filled cryogenic stopping cell (CSC). They were then extracted from the CSC and injected into a high-resolution multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS). The excitation energy of the isomer and, for the first time, the isomeric-to-ground state ratio were determined from the measured mass spectrum. In the subsequent experimental step, the isomers were spatially separated from the ions in the ground state by an ion deflector and finally collected with a silicon detector for decay spectroscopy. This pioneering experimental result opens up unique perspectives for isomer-resolved studies. With this versatile experimental method new isomers with half-lives longer than a few milliseconds can be discovered and their decay properties can be measured with highest sensitivity and selectivity. These experiments can be extended to studies with isomeric beams in nuclear reactions.

  15. A simple electron time-of-flight spectrometer for ultrafast vacuum ultraviolet photoelectron spectroscopy of liquid solutions

    SciTech Connect

    Arrell, C. A. Ojeda, J.; Mourik, F. van; Chergui, M.; Sabbar, M.; Gallmann, L.; Keller, U.; Okell, W. A.; Witting, T.; Siegel, T.; Diveki, Z.; Hutchinson, S.; Tisch, J. W.G.; Marangos, J. P.; Chapman, R. T.; Cacho, C.; Rodrigues, N.; Turcu, I. C.E.; Springate, E.

    2014-10-01

    We present a simple electron time of flight spectrometer for time resolved photoelectron spectroscopy of liquid samples using a vacuum ultraviolet (VUV) source produced by high-harmonic generation. The field free spectrometer coupled with the time-preserving monochromator for the VUV at the Artemis facility of the Rutherford Appleton Laboratory achieves an energy resolution of 0.65 eV at 40 eV with a sub 100 fs temporal resolution. A key feature of the design is a differentially pumped drift tube allowing a microliquid jet to be aligned and started at ambient atmosphere while preserving a pressure of 10⁻¹ mbar at the micro channel plate detector. The pumping requirements for photoelectron (PE) spectroscopy in vacuum are presented, while the instrument performance is demonstrated with PE spectra of salt solutions in water. The capability of the instrument for time resolved measurements is demonstrated by observing the ultrafast (50 fs) vibrational excitation of water leading to temporary proton transfer.

  16. Understanding inelastically scattered neutrons from water on a time-of-flight small-angle neutron scattering (SANS) instrument

    NASA Astrophysics Data System (ADS)

    Do, Changwoo; Heller, William T.; Stanley, Christopher; Gallmeier, Franz X.; Doucet, Mathieu; Smith, Gregory S.

    2014-02-01

    It is generally assumed by most of the small-angle neutron scattering (SANS) user community that a neutron's energy is unchanged during SANS measurements. Here, the scattering from water, specifically light water, was measured on the EQ-SANS instrument, a time-of-flight (TOF) SANS instrument located at the Spallation Neutron Source of Oak Ridge National Laboratory. A significant inelastic process was observed in the TOF spectra of neutrons scattered from water. Analysis of the TOF spectra from the sample showed that the scattered neutrons have energies consistent with room-temperature thermal energies (~20 meV) regardless of the incident neutron's energy. With the aid of Monte Carlo particle transport simulations, we conclude that the thermalization process within the sample results in faster neutrons that arrive at the detector earlier than expected based on the incident neutron energies. This thermalization process impacts the measured SANS intensities in a manner that will ultimately be sample- and temperature-dependent, necessitating careful processing of the raw data into the SANS cross-section.

  17. Physical and clinical performance of the mCT time-of-flight PET/CT scanner

    NASA Astrophysics Data System (ADS)

    Jakoby, B. W.; Bercier, Y.; Conti, M.; Casey, M. E.; Bendriem, B.; Townsend, D. W.

    2011-04-01

    Time-of-flight (TOF) measurement capability promises to improve PET image quality. We characterized the physical and clinical PET performance of the first Biograph mCT TOF PET/CT scanner (Siemens Medical Solutions USA, Inc.) in comparison with its predecessor, the Biograph TruePoint TrueV. In particular, we defined the improvements with TOF. The physical performance was evaluated according to the National Electrical Manufacturers Association (NEMA) NU 2-2007 standard with additional measurements to specifically address the TOF capability. Patient data were analyzed to obtain the clinical performance of the scanner. As expected for the same size crystal detectors, a similar spatial resolution was measured on the mCT as on the TruePoint TrueV. The mCT demonstrated modestly higher sensitivity (increase by 19.7 ± 2.8%) and peak noise equivalent count rate (NECR) (increase by 15.5 ± 5.7%) with similar scatter fractions. The energy, time and spatial resolutions for a varying single count rate of up to 55 Mcps resulted in 11.5 ± 0.2% (FWHM), 527.5 ± 4.9 ps (FWHM) and 4.1 ± 0.0 mm (FWHM), respectively. With the addition of TOF, the mCT also produced substantially higher image contrast recovery and signal-to-noise ratios in a clinically-relevant phantom geometry. The benefits of TOF were clearly demonstrated in representative patient images.

  18. A simple electron time-of-flight spectrometer for ultrafast vacuum ultraviolet photoelectron spectroscopy of liquid solutions

    NASA Astrophysics Data System (ADS)

    Arrell, C. A.; Ojeda, J.; Sabbar, M.; Okell, W. A.; Witting, T.; Siegel, T.; Diveki, Z.; Hutchinson, S.; Gallmann, L.; Keller, U.; van Mourik, F.; Chapman, R. T.; Cacho, C.; Rodrigues, N.; Turcu, I. C. E.; Tisch, J. W. G.; Springate, E.; Marangos, J. P.; Chergui, M.

    2014-10-01

    We present a simple electron time of flight spectrometer for time resolved photoelectron spectroscopy of liquid samples using a vacuum ultraviolet (VUV) source produced by high-harmonic generation. The field free spectrometer coupled with the time-preserving monochromator for the VUV at the Artemis facility of the Rutherford Appleton Laboratory achieves an energy resolution of 0.65 eV at 40 eV with a sub 100 fs temporal resolution. A key feature of the design is a differentially pumped drift tube allowing a microliquid jet to be aligned and started at ambient atmosphere while preserving a pressure of 10-1 mbar at the micro channel plate detector. The pumping requirements for photoelectron (PE) spectroscopy in vacuum are presented, while the instrument performance is demonstrated with PE spectra of salt solutions in water. The capability of the instrument for time resolved measurements is demonstrated by observing the ultrafast (50 fs) vibrational excitation of water leading to temporary proton transfer.

  19. Stopping power measurements of He ions in Si and SiC by time-of-flight spectrometry

    SciTech Connect

    Zhang, Yanwen; Jensen, Jens; Possnert, Goran; Grove, David A.; Bae, In-Tae; Weber, William J.

    2007-08-01

    Electronic energy loss is the fundamental mechanism accountable for the response of materials to ions. Helium particles are a product from alpha decay in nuclear waste materials, and helium ions are widely used as projectiles in ion beam analysis. Current work introduces a straightforward approach to determine electronic stopping powers of He ions in Si and SiC over a continuous range of energies. In transmission geometry, the energy loss of He ions in self-supporting stopping foils of Si and SiC is measured using a Time-of-Flight (TOF) set-up. The energy of individual heavy ions prior to impingement on the foil is determined from its TOF data; the exit energy after the stopping foil is essentially measured using the Si detector, for which every channel has been calibrated using TOF data without the stopping foil present. The measured stopping powers demonstrate excellent repeatability of this experimental approach and good reliability as compared with pervious data from the literature and theoretical predictions.

  20. Tandem time-of-flight mass spectrometer (TOF-TOF) with a quadratic-field ion mirror

    NASA Astrophysics Data System (ADS)

    Giannakopulos, Anastassios E.; Thomas, Benjamin; Colburn, Alex W.; Reynolds, David J.; Raptakis, Emmanuel N.; Makarov, Alexander A.; Derrick, Peter J.

    2002-05-01

    A tandem time-of-flight (TOF-TOF) mass spectrometer comprised of two ion mirrors is described. The first ion mirror, which is a linear-field, single-stage mirror (MS1) with an intermediate collision cell, has been designed to provide the temporal focus necessary for the second, quadratic-field ion mirror (MS2) to function effectively. Due to the wide energy-range focusing capabilities of the quadratic field employed in the second ion mirror all the fragment ions can be collected in one spectrum without the need to step the reflecting working voltage of the MS2. The size of the active area of the microchannel plate detector used in the preliminary experiments was the limiting factor governing the collection efficiently of fragment ions. The use of the first ion mirror to provide temporal focusing of the precursor ion packet at the first focal point of the quadratic mirror used as the MS2 requires no alteration of the focusing conditions for different masses, in contrast to delayed extraction or postsource pulsed focusing. Precursor ions formed by matrix-assisted laser desorption/ionization were mass-selected with an ion gate located before the collision cell and the fragment ions were mass analyzed using the quadratic-field ion mirror. Experimental results demonstrating effective high-energy collision-induced dissociation of polymer and fullerene molecule-ions are presented.

  1. Development of an ion trap/multi-turn time-of-flight mass spectrometer with potential- lift.

    PubMed

    Iwamoto, Kenichi; Nagao, Hirofumi; Toyoda, Michisato

    2009-01-01

    An ion trap/multi-turn time-of-flight (ToF) mass spectrometer with potential-lift has been developed. This system consists of an external ion source, a lens system, an ion trap, a potential-lift, a multi-turn ToF mass spectrometer and a detector. The ion trap consists of hyperbolic electrode cross-sections (Paul trap) and is used as an ion storage device. The potential-lift, which is part of the flight tube, was attached between the ion trap and the multi-turn ToF mass spectrometer. The potential-lift is known to be useful for increasing the kinetic energy of the ions. In order to check the ability of the potential-lift, mass distributions of [(CsI)(n) Cs]+ clusters (n = 1-9) were measured. The relative intensity ratios of the [(CsI)(n)Cs]+ clusters were consistent with the results obtained using other apparatus. To check the properties of the new apparatus, Xe+ isotopes were analyzed using either a linear or multi-turn ToF mass spectrometer. In the linear mode, the mass resolution was 500. In the multi-turn mode, the resolution depended on the number of cycles of the multi-turn ToF mass spectrometer; the mass resolution was 4400 (FWHM) after nine cycles. This new apparatus with a high resolution will be useful for measurements of ion-molecule reactions and photodissociations. PMID:19423910

  2. Evaluation of Inductively Couple Plasma-time-of-Flight Mass Spectrometry for Laser Ablation Analyses

    SciTech Connect

    S.J. Bajic; D.B. Aeschliman; D.P. Baldwin; R.S. Houk

    2003-09-30

    The purpose of this trip to LECO Corporation was to test the non-matrix matched calibration method and the principal component analysis (PCA) method on a laser ablation-inductively coupled plasma-time of flight mass spectrometry (LA-ICP-TOFMS) system. An LA-ICP-TOFMS system allows for multielement single-shot analysis as well as spatial analysis on small samples, because the TOFMS acquires an entire mass spectrum for all ions extracted simultaneously from the ICP. The TOFMS system differs from the double-focusing mass spectrometer, on which the above methods were developed, by having lower sensitivity and lower mass resolution.

  3. Evaluation of anisotropic charge carrier mobility of perylene single crystals by time-of-flight method

    NASA Astrophysics Data System (ADS)

    Kougo, Junichi; Ishikawa, Ken

    2016-03-01

    The charge carrier mobilities along the vertical and lateral directions of perylene platelet single crystals were measured by the time-of-flight (TOF) method. In the lateral directional measurement, the entire region between electrodes was irradiated to obtain measurable signals. The transient photocurrent was different from the conventional TOF measurements; hence, we developed an analytic method for lateral directional measurement. The electron mobilities along the thickness and lateral directions were 0.33 and 2.0 cm2·V-1·s-1 and the hole mobilities were 0.12 and 0.6 cm2·V-1·s-1, respectively.

  4. Resolution of time-of-flight mass spectrometers evaluated for secondary neutral mass spectrometry

    NASA Astrophysics Data System (ADS)

    Kato, Makoto; Mogami, Akinori; Naito, Motohiro; Ichimura, Shingo; Shimizu, Hazime

    1988-09-01

    Mass resolution of a time-of-flight mass spectrometer with a two-stage electrostatic reflector is calculated for secondary neutral mass spectrometry. The instrument parameters are optimized for energy and space focusing: correcting the flight time difference due to the energy width ΔE of sputtered particles and the spatial width Δs of an ionizing laser beam. The effect of Δs can be compensated by applying an acceleration field to the ionizing region, and the maximum resolution becomes about 1000 for ΔE=10 eV and Δs=1.0 mm.

  5. Note: A novel dual-channel time-of-flight mass spectrometer for photoelectron imaging spectroscopy

    SciTech Connect

    Qin Zhengbo; Wu Xia; Tang Zichao

    2013-06-15

    A novel dual-channel time-of-flight mass spectrometer (D-TOFMS) has been designed to select anions in the photoelectron imaging measurements. In this instrument, the radiation laser can be triggered precisely to overlap with the selected ion cloud at the first-order space focusing plane. Compared with that of the conventional single channel TOFMS, the in situ mass selection performance of D-TOFMS is significantly improved. Preliminary experiment results are presented for the mass-selected photodetachment spectrum of F{sup -} to demonstrate the capability of the instrument.

  6. Revealing Single-Trap Condensate Fragmentation by Measuring Density-Density Correlations after Time of Flight

    NASA Astrophysics Data System (ADS)

    Kang, Myung-Kyun; Fischer, Uwe R.

    2014-10-01

    We consider ultracold bosonic atoms in a single trap in the Thomas-Fermi regime, forming many-body states corresponding to stable macroscopically fragmented two-mode condensates. It is demonstrated that upon free expansion of the gas, the spatial dependence of the density-density correlations at late times provides a unique signature of fragmentation. This hallmark of fragmented condensate many-body states in a single trap is due to the fact that the time of flight modifies the correlation signal such that two opposite points in the expanding cloud become uncorrelated, in distinction to a nonfragmented Bose-Einstein condensate, where they remain correlated.

  7. Stopping power measurements with the Time-of-Flight (ToF) technique

    DOE PAGESBeta

    Fontana, Cristiano L.; Chen, Chien-Hung; Crespillo, Miguel L.; Graham, Joseph T.; Xue, Haizhou; Zhang, Yanwen; Weber, William J.

    2015-11-10

    In our review of measurements of the stopping power of ions in matter is presented along with new measurements of the stopping powers of O, Si, Ti, and Au ions in self-supporting thin foils of SiO2, Nb2O5, and Ta2O5. Moreover, a Time-of-Flight system at the Ion Beam Materials Laboratory at the University of Tennessee, Knoxville, was used in transmission geometry in order to reduce experimental uncertainties. Finally, the resulting stopping powers show good precision and accuracy and corroborate previously quoted values in the literature. New stopping data are determined.

  8. Time-of-flight velocity analysis of atomic and molecular beams

    NASA Technical Reports Server (NTRS)

    Hagena, O. F.; Varma, A. K.

    1968-01-01

    Conditions required for resolving a given beam speed distribution were evaluated by calculating the time-of-flight (TOF) signal for a finite open time of the beam shutter. Design criteria for a beam chopper and detection system are discussed in terms of the resolution, the range of speeds to be measured, and the optimum signal to noise ratio. A TOF system for detection of high intensity molecular beams with large speed ratios, as well as for low intensity scattered beams, is described. Experimental results are presented.

  9. A time-of-flight backscattering spectrometer at the Spallation Neutron Source, BASIS

    SciTech Connect

    Mamontov, E.; Herwig, K. W.

    2011-08-15

    We describe the design and current performance of the backscattering silicon spectrometer (BASIS), a time-of-flight backscattering spectrometer built at the spallation neutron source (SNS) of the Oak Ridge National Laboratory (ORNL). BASIS is the first silicon-based backscattering spectrometer installed at a spallation neutron source. In addition to high intensity, it offers a high-energy resolution of about 3.5 {mu}eV and a large and variable energy transfer range. These ensure an excellent overlap with the dynamic ranges accessible at other inelastic spectrometers at the SNS.

  10. Effect of trapped ions in a gated time-of-flight apparatus

    NASA Technical Reports Server (NTRS)

    Martus, K. E.; Orient, O. J.; Chutjian, A.

    1993-01-01

    A three-mesh gate is used in a time-of-flight (TOF) apparatus to analyze the velocity of positive ions. Test results and a theoretical description are presented of an effect arising from trapping ions between meshes of a two-gate TOF velocity analyzer. The entrapped ions produce a side peak in the TOF spectra corresponding to faster ions. The onset and relative height of the side peak is dependent on the gating voltage and risetime of the pulsing electronics, while the relative intensity depends upon the velocity being sampled and the ratio of the gate width to duration.

  11. Analysis of the neutron time-of-flight spectra from inertial confinement fusion experiments

    DOE PAGESBeta

    Hatarik, R.; Sayre, D. B.; Caggiano, J. A.; Phillips, T.; Eckart, M. J.; Bond, E. J.; Cerjan, C.; Grim, G. P.; Hartouni, E. P.; Knauer, J. P.; et al

    2015-11-12

    For a long time, neutron time-of-flight diagnostics been used to characterize the neutron spectrum produced by inertial confinement fusion experiments. The primary diagnostic goals are to extract the d+t→n+α (DT) and d+d→n+³He (DD) neutron yields and peak widths, and the amount DT scattering relative to its unscattered yield, which is also known as the down-scatter ratio (DSR). These quantities are used to infer yield weighted plasma conditions, such as ion temperature (Tion) and cold fuel areal density. We explain such novel methodologies used to determine neutron yield, apparent Tion and DSR.

  12. Analysis of the neutron time-of-flight spectra from inertial confinement fusion experiments

    SciTech Connect

    Hatarik, R.; Sayre, D. B.; Caggiano, J. A.; Phillips, T.; Eckart, M. J.; Bond, E. J.; Cerjan, C.; Grim, G. P.; Hartouni, E. P.; Knauer, J. P.; Mcnaney, J. M.; Munro, D. H.

    2015-11-12

    For a long time, neutron time-of-flight diagnostics been used to characterize the neutron spectrum produced by inertial confinement fusion experiments. The primary diagnostic goals are to extract the d+t→n+α (DT) and d+d→n+³He (DD) neutron yields and peak widths, and the amount DT scattering relative to its unscattered yield, which is also known as the down-scatter ratio (DSR). These quantities are used to infer yield weighted plasma conditions, such as ion temperature (Tion) and cold fuel areal density. We explain such novel methodologies used to determine neutron yield, apparent Tion and DSR.

  13. Time-of-flight detection of ultra-cold atoms using resonant frequency modulation imaging.

    PubMed

    Hardman, K S; Wigley, P B; Everitt, P J; Manju, P; Kuhn, C C N; Robins, N P

    2016-06-01

    Resonant frequency modulation imaging is used to detect free falling ultra-cold atoms. A theoretical comparison of fluorescence imaging (FI) and frequency modulation imaging (FMI) is made, indicating that for low optical depth clouds, FMI accomplished a higher signal-to-noise ratio under conditions necessary for a 200 μm spatially resolved atom interferometer. A 750 ms time-of-flight measurement reveals near atom shot-noise limited number measurements of 2×106 Bose-condensed Rb87 atoms. The detection system is applied to high precision spinor BEC based atom interferometer. PMID:27244400

  14. Development of laser assisted nanometric resolution scanning tunneling microscopy time-of-flight mass analyzer system

    NASA Astrophysics Data System (ADS)

    Ding, Y.; Micheletto, R.; Hanada, H.; Nagamura, T.; Okazaki, S.

    2002-09-01

    This study describes a ground-breaking process that provides a direct highly localized measurement of the atomic mass on surfaces at room temperature. Employing an original system that joins a scanning tunneling microscopy (STM) device and a time-of-flight (TOF) mass analyzer, we could locally ionize surface atoms by the combination of an optical laser pulse and an appropriate voltage variation between the sample and the STM tip. Desorbed ions were accelerated and detected by a TOF chamber. Detection and discrimination of single atomic species from nanolocalized area have been demonstrated for the first time.

  15. Electron pair emission detected by time-of-flight spectrometers: Recent progress

    SciTech Connect

    Huth, Michael; Schumann, Frank O.; Chiang, Cheng-Tien; Trützschler, Andreas; Kirschner, Jürgen; Widdra, Wolf

    2014-02-10

    We present results for electron coincidence spectroscopy using two time-of-flight (ToF) spectrometers. Excited by electron impact, the energy and momentum distribution of electron pairs emitted from the Cu(111) surface are resolved and a spectral feature related to the Shockley surface state is identified. By combining the two ToF spectrometers with a high-order harmonic generation light source, we demonstrate double photoemission spectroscopy in the laboratory that required synchrotron radiation in the past. Utilizing this setup, we report results for (γ,2e) on NiO(001) on Ag(001) excited with light at 30 eV photon energy.

  16. Quantum time-of-flight measurements: Kicked clock versus continuous clock

    SciTech Connect

    Alonso, Daniel; Sala Mayato, R.; Muga, J.G.

    2003-03-01

    The measurement of time durations or instants of occurrence of events has been frequently modeled 'operationally' by coupling the system of interest to a ''clock.'' According to several of these models, the operational approach is limited at low energies because the perturbation of the clock does not allow to reproduce accurately the corresponding ideal time quantity, defined for the system in isolation. We show that, for a time-of-flight measurement model that can be set to measure dwell or arrival times, these limitations may be overcome by extending the range of energies where the clock works properly using pulsed couplings rather than continuous ones.

  17. Time of flight measurement of speed of sound in air with a computer sound card

    NASA Astrophysics Data System (ADS)

    Aljalal, Abdulaziz

    2014-11-01

    A computer sound card and freely available audio editing software are used to measure accurately the speed of sound in air using the time-of-flight method. In addition to speed of sound measurement, inversion behaviour upon reflection from an open and closed end of a pipe is demonstrated. Also, it is demonstrated that the reflection at an open end of a pipe occurs slightly outside the pipe. The equipment needed is readily available to any student with access to a microphone, loudspeaker and computer.

  18. WIDEBAND ULTRASONIC TIME OF FLIGHT DIFFRACTION COMBINING B-SCANS AND CROSS-SECTIONAL IMAGING

    SciTech Connect

    Petcher, P. A.; Dixon, S.

    2009-03-03

    Time of Flight Diffraction and Imaging (ToFDI) is a new technique utilizing a sparse array of transducers and signal processing to improve B-Scan output and create a cross-sectional image of a sample. This paper describes preliminary work demonstrating the concept, including; Finite Element Modelling (FEM), basic processing, likely applications. The eventual aim is for fast and automated detection, identification, positioning and sizing for all defects in a sample with known basic characteristics, such as bulk and shear elastic moduli.

  19. Solid Phase Microextraction and Miniature Time-of-Flight Mass Spectrometer

    SciTech Connect

    Hiller, j.m.

    1999-01-26

    A miniature mass spectrometer, based on the time-of-flight principle, has been developed for the detection of chemical warfare agent precursor molecules. The instrument, with minor modifications, could fulfill many of the needs for sensing organic molecules in various Defense Programs, including Enhanced Surveillance. The basic footprint of the instrument is about that of a lunch box. The instrument has a mass range to about 300, has parts-per-trillion detection limits, and can return spectra in less than a second. The instrument can also detect permanent gases and is especially sensitive to hydrogen. In volume, the device could be manufactured for under $5000.

  20. Waveform-Sampling Electronics for a Whole-Body Time-of-Flight PET Scanner

    PubMed Central

    Ashmanskas, W. J.; LeGeyt, B. C.; Newcomer, F. M.; Panetta, J. V.; Ryan, W. A.; Van Berg, R.; Wiener, R. I.; Karp Fellow, J. S.

    2014-01-01

    Waveform sampling is an appealing technique for instruments requiring precision time and pulse-height measurements. Sampling each PMT waveform at oscilloscope-like rates of several gigasamples per second enables one to process PMT signals digitally, which in turn makes it straightforward to optimize timing resolution and amplitude (energy and position) resolution in response to calibration effects, pile-up effects, and other systematic sources of waveform variation. We describe a system design and preliminary implementation that neatly maps waveform-sampling technology onto the LaPET prototype whole-body time-of-flight PET scanner that serves as the platform for testing this new technology. PMID:25484379

  1. A radial collimator for a time-of-flight neutron spectrometer

    SciTech Connect

    Stone, M. B.; Abernathy, D. L.; Niedziela, J. L.; Loguillo, M. J.; Overbay, M. A.

    2014-08-15

    We have engineered and installed a radial collimator for use in the scattered beam of a neutron time-of-flight spectrometer at a spallation neutron source. The radial collimator may be used with both thermal and epithermal neutrons, reducing the detected scattering intensity due to material outside of the sample region substantially. The collimator is located inside of the sample chamber of the instrument, which routinely cycles between atmospheric conditions and cryogenic vacuum. The oscillation and support mechanism of the collimator allow it to be removed from use without breaking vacuum. We describe here the design and characterization of this radial collimator.

  2. A radial collimator for a time-of-flight neutron spectrometer.

    PubMed

    Stone, M B; Niedziela, J L; Loguillo, M J; Overbay, M A; Abernathy, D L

    2014-08-01

    We have engineered and installed a radial collimator for use in the scattered beam of a neutron time-of-flight spectrometer at a spallation neutron source. The radial collimator may be used with both thermal and epithermal neutrons, reducing the detected scattering intensity due to material outside of the sample region substantially. The collimator is located inside of the sample chamber of the instrument, which routinely cycles between atmospheric conditions and cryogenic vacuum. The oscillation and support mechanism of the collimator allow it to be removed from use without breaking vacuum. We describe here the design and characterization of this radial collimator. PMID:25173306

  3. A radial collimator for a time-of-flight neutron spectrometer

    SciTech Connect

    Stone, Matthew B; Niedziela, Jennifer L; Loguillo, Mark; Overbay, Mark A; Abernathy, Douglas L

    2013-01-01

    We have engineered and installed a radial collimator for use in the scattered beam of a neutron time-of-flight spectrometer at a spallation neutron source. The radial collimator may be used with both thermal and epithermal neutrons, reducing the detected scattering intensity due to material outside of the sample region substantially. The collimator is located inside of the sample chamber of the instrument, which routinely cycles between atmospheric conditions and cryogenic vacuum. The oscillation and support mechanism of the collimator allow it to be removed from use without breaking vacuum. We describe here the design and characterization of this radial collimator.

  4. Reply to 'Comment on 'Quantum time-of-flight distribution for cold trapped atoms''

    SciTech Connect

    Ali, Md. Manirul; Home, Dipankar; Pan, Alok K.; Majumdar, A. S.

    2008-02-15

    In their comment Gomes et al. [Phys. Rev. A 77, 026101 (2008)] have questioned the possibility of empirically testable differences existing between the semiclassical time of flight distribution for cold trapped atoms and a quantum distribution discussed by us recently [Ali et al., Phys. Rev. A 75, 042110 (2007).]. We argue that their criticism is based on a semiclassical treatment having restricted applicability for a particular trapping potential. Their claim does not preclude, in general, the possibility of differences between the semiclassical calculations and fully quantum results for the arrival time distribution of freely falling atoms.

  5. Revealing single-trap condensate fragmentation by measuring density-density correlations after time of flight.

    PubMed

    Kang, Myung-Kyun; Fischer, Uwe R

    2014-10-01

    We consider ultracold bosonic atoms in a single trap in the Thomas-Fermi regime, forming many-body states corresponding to stable macroscopically fragmented two-mode condensates. It is demonstrated that upon free expansion of the gas, the spatial dependence of the density-density correlations at late times provides a unique signature of fragmentation. This hallmark of fragmented condensate many-body states in a single trap is due to the fact that the time of flight modifies the correlation signal such that two opposite points in the expanding cloud become uncorrelated, in distinction to a nonfragmented Bose-Einstein condensate, where they remain correlated. PMID:25325623

  6. Stopping power measurements with the Time-of-Flight (ToF) technique

    NASA Astrophysics Data System (ADS)

    Fontana, Cristiano L.; Chen, Chien-Hung; Crespillo, Miguel L.; Graham, Joseph T.; Xue, Haizhou; Zhang, Yanwen; Weber, William J.

    2016-01-01

    A review of measurements of the stopping power of ions in matter is presented along with new measurements of the stopping powers of O, Si, Ti, and Au ions in self-supporting thin foils of SiO2, Nb2O5, and Ta2O5. A Time-of-Flight system at the Ion Beam Materials Laboratory at the University of Tennessee, Knoxville, was used in transmission geometry in order to reduce experimental uncertainties. The resulting stopping powers show good precision and accuracy and corroborate previously quoted values in the literature. New stopping data are determined.

  7. Upgrade of the ALICE Inner Tracking System

    NASA Astrophysics Data System (ADS)

    Keil, M.

    2015-03-01

    ALICE (A Large Ion Collider Experiment) is studying heavy-ion collisions at the CERN LHC, with the aim of forming, under extreme conditions of temperature and energy density, a Quark-Gluon Plasma (QGP) and studying its properties. The ALICE Collaboration is preparing a major upgrade of the experimental apparatus, planned for installation in the second long LHC shutdown in the years 2018-2019. A key element of the ALICE upgrade is the construction of a new, ultra-light, high-resolution Inner Tracking System (ITS) . The primary focus of the new ITS is on improving the performance for detection of heavy-flavour hadrons, and of thermal photons and low-mass di-electrons emitted by the QGP . With respect to the current detector, the new ITS will significantly enhance the determination of the distance of closest approach of a track to the primary vertex, the tracking efficiency at low transverse momenta, and the read-out rate capabilities. This will be achieved by seven concentric detector layers based on a 50 μm thick CMOS pixel sensor with a pixel pitch of about 30× 30 μm2. A key feature of the new ITS, which is optimized for high tracking accuracy at low transverse momenta, is the very low mass of the three innermost layers, which feature a material thickness of 0.3% X0 per layer. This contribution describes the design goals and layout of the new ALICE ITS, a summary of the R&D activities, with focus on the technical implementation of the main detector components, and the projected detector performance.

  8. Overview of anisotropic flow measurements from ALICE

    NASA Astrophysics Data System (ADS)

    Zhou, You

    2016-05-01

    Anisotropic flow is an important observable to study the properties of the hot and dense matter, the Quark Gluon Plasma (QGP), created in heavy-ion collisions. Measurements of anisotropic flow for inclusive and identified charged hadrons are reported in Pb-Pb, p-Pb and pp collisions with the ALICE detector. The comparison of experimental measurements to various theoretical calculations are also presented in these proceedings.

  9. Status of Fast Interaction Trigger for ALICE Upgrade

    NASA Astrophysics Data System (ADS)

    Karavicheva, T. L.; Kurepin, A. B.; Trzaska, W. H.

    2015-06-01

    As a result of the LHC upgrade after the Long Shutdown 2, the expected luminosity and collision rate during the so called Run 3 will considerably exceed the design parameters for several of the key ALICE detectors systems including the forward trigger detectors. Furthermore, the introduction of a new Muon Forward Tracker significantly reduces the space envelope available for the upgraded Fast Interaction Trigger (FIT) detector on the muon spectrometer side. At the same time, FIT is expected to match and even exceed the functionality and performance currently secured by three ALICE sub-detectors: the time zero detector (T0), the VZERO system, and the Forward Multiplicity Detector (FMD). The harsh conditions of Run 3 would accelerate the ageing and radiation damage (detectable already during Run 1) of the FIT detector if we were to use standard PMTs. The solution came thanks to the latest developments in MCP-PMT technology providing compact photo sensors with excellent characteristics and stability.

  10. Accurate estimation of airborne ultrasonic time-of-flight for overlapping echoes.

    PubMed

    Sarabia, Esther G; Llata, Jose R; Robla, Sandra; Torre-Ferrero, Carlos; Oria, Juan P

    2013-01-01

    In this work, an analysis of the transmission of ultrasonic signals generated by piezoelectric sensors for air applications is presented. Based on this analysis, an ultrasonic response model is obtained for its application to the recognition of objects and structured environments for navigation by autonomous mobile robots. This model enables the analysis of the ultrasonic response that is generated using a pair of sensors in transmitter-receiver configuration using the pulse-echo technique. This is very interesting for recognizing surfaces that simultaneously generate a multiple echo response. This model takes into account the effect of the radiation pattern, the resonant frequency of the sensor, the number of cycles of the excitation pulse, the dynamics of the sensor and the attenuation with distance in the medium. This model has been developed, programmed and verified through a battery of experimental tests. Using this model a new procedure for obtaining accurate time of flight is proposed. This new method is compared with traditional ones, such as threshold or correlation, to highlight its advantages and drawbacks. Finally the advantages of this method are demonstrated for calculating multiple times of flight when the echo is formed by several overlapping echoes. PMID:24284774

  11. Beam transport and polarization at TOPAS, the thermal time-of-flight spectrometer with polarization analysis

    NASA Astrophysics Data System (ADS)

    Voigt, J.; Babcock, E.; Brückel, T.

    2010-02-01

    We present the design for the polarization analysis of the future thermal time-of-flight spectrometer at the Juelich Centre for Neutron Science (JCNS) at the FRM II. TOPAS is a time-of-flight spectrometer covering a range of incident energies 20 meV < Ei < 160 meV and an angular range -3° < 2θ < 150°. A set of Fermi choppers selects the incoming energy Ei with a resolution up to 3 %. The instrument is optimized for a high flux on small samples using an elliptical neutron guide. The special feature of TOPAS is the polarization analysis. The incident polarization will be realized by means of a 3He continuously pumped polarizer, which is a downscaled version of the device developed for small angle applications at JCNS. The polarization analysis over a wide angular range demands either short distances between the sample and the analyzer or a large volume of polarized 3He. Here we propose the latter alternative to allow the study of magnetic samples and modest magnetic fields at the sample position.

  12. Evaluating the capability of time-of-flight cameras for accurately imaging a cyclically loaded beam

    NASA Astrophysics Data System (ADS)

    Lahamy, Hervé; Lichti, Derek; El-Badry, Mamdouh; Qi, Xiaojuan; Detchev, Ivan; Steward, Jeremy; Moravvej, Mohammad

    2015-05-01

    Time-of-flight cameras are used for diverse applications ranging from human-machine interfaces and gaming to robotics and earth topography. This paper aims at evaluating the capability of the Mesa Imaging SR4000 and the Microsoft Kinect 2.0 time-of-flight cameras for accurately imaging the top surface of a concrete beam subjected to fatigue loading in laboratory conditions. Whereas previous work has demonstrated the success of such sensors for measuring the response at point locations, the aim here is to measure the entire beam surface in support of the overall objective of evaluating the effectiveness of concrete beam reinforcement with steel fibre reinforced polymer sheets. After applying corrections for lens distortions to the data and differencing images over time to remove systematic errors due to internal scattering, the periodic deflections experienced by the beam have been estimated for the entire top surface of the beam and at witness plates attached. The results have been assessed by comparison with measurements from highly-accurate laser displacement transducers. This study concludes that both the Microsoft Kinect 2.0 and the Mesa Imaging SR4000s are capable of sensing a moving surface with sub-millimeter accuracy once the image distortions have been modeled and removed.

  13. Identification of rolling circulating tumor cells using photoacoustic time-of-flight method

    NASA Astrophysics Data System (ADS)

    Sarimollaoglu, Mustafa; Nedosekin, Dmitry A.; Galanzha, Ekaterina I.; Zharov, Vladimir P.

    2013-03-01

    Existing optical techniques for in vivo measurement of blood flow velocity are not quite applicable for determination of velocity of individual cells or nanoparticles. A time-of-flight photoacoustic (PA) technique can solve this problem by measuring the transient PA signal width, which is related to the cell velocity passing the laser beam. This technique was demonstrated in vivo using an animal (mouse) model by estimating the velocity of nanoparticles, and red and white blood cells labeled with conjugated gold nanorods (GNRs) in the bloodstream. Here we describe the features and the parameters of novel modifications to the PA time-of-flight method and its new application for real-time monitoring of circulating tumor cells (CTCs), such as B16F10 melanoma. This method provided, for the first time, identification of rolling CTCs in analogy to rolling white blood cells and CTC aggregates. Specifically, monitoring of PA signal widths from CTCs in mouse ear microvessels revealed double maxima in peak-width histograms associated with the fast moving portion of CTCs in central flow and slowly rolling CTCs in analogy to white blood cells. We also developed a two-parameter plot representing PA peak amplitude and peak widths. This method allowed identification of fast-moving individual CTCs, CTC aggregates, and rolling CTCs. The discovery of rolling CTCs in relatively large blood vessels indicates a higher probability of CTC extravasations, further increasing the possibility of metastasis through rolling mechanism in addition to mechanical capturing of CTCs in small vessels.

  14. Accurate Estimation of Airborne Ultrasonic Time-of-Flight for Overlapping Echoes

    PubMed Central

    Sarabia, Esther G.; Llata, Jose R.; Robla, Sandra; Torre-Ferrero, Carlos; Oria, Juan P.

    2013-01-01

    In this work, an analysis of the transmission of ultrasonic signals generated by piezoelectric sensors for air applications is presented. Based on this analysis, an ultrasonic response model is obtained for its application to the recognition of objects and structured environments for navigation by autonomous mobile robots. This model enables the analysis of the ultrasonic response that is generated using a pair of sensors in transmitter-receiver configuration using the pulse-echo technique. This is very interesting for recognizing surfaces that simultaneously generate a multiple echo response. This model takes into account the effect of the radiation pattern, the resonant frequency of the sensor, the number of cycles of the excitation pulse, the dynamics of the sensor and the attenuation with distance in the medium. This model has been developed, programmed and verified through a battery of experimental tests. Using this model a new procedure for obtaining accurate time of flight is proposed. This new method is compared with traditional ones, such as threshold or correlation, to highlight its advantages and drawbacks. Finally the advantages of this method are demonstrated for calculating multiple times of flight when the echo is formed by several overlapping echoes. PMID:24284774

  15. Slow light and chromatic temporal dispersion in photonic crystal waveguides using femtosecond time of flight.

    PubMed

    Finlayson, C E; Cattaneo, F; Perney, N M B; Baumberg, J J; Netti, M C; Zoorob, M E; Charlton, M D B; Parker, G J

    2006-01-01

    We report time-of-flight experiments on photonic-crystal waveguide structures using optical Kerr gating of a femtosecond white-light supercontinuum. These photonic-crystal structures, based on engineered silicon-nitride slab waveguides, possess broadband low-loss guiding properties, allowing the group velocity dispersion of optical pulses to be directly tracked as a function of wavelength. This dispersion is shown to be radically disrupted by the spectral band gaps associated with the photonic-crystal periodicity. Increased time-of-flight effects, or "slowed light," are clearly observed at the edges of band gaps in agreement with two-dimensional plane-wave theoretical models of group velocity dispersion. A universal model for slow light in such photonic crystals is proposed, which shows that slow light is controlled predominantly by the detuning from, and the size of, the photonic band gaps. Slowed light observed up to time delays of approximately 1 ps, corresponds to anomalous dispersion of approximately 3.5 ps/nm per mm of the photonic crystal structure. From the decreasing intensity of time-gated slow light as a function of time delay, we estimate the characteristic losses of modes which are guided in the spectral proximity of the photonic band gaps. PMID:16486307

  16. Electron field emission from freestanding Diamond nanomembranes and Application to time-of-flight mass spectrometry

    NASA Astrophysics Data System (ADS)

    Kim, Hyunseok; Park, Jonghoo; Shin, Hyuncheol; Blick, Robert H.

    2013-03-01

    We introduce a prototype of a freestanding diamond nanomembrane for large protein detection in time-of-flight mass spectrometry. Doped diamond as a material for mass spectroscopy is extremely interesting due to its mechanical and electrical properties. The freestanding diamond nanomembranes we are able to fabricate have lateral extensions of 400 μm × 400 μm with a thickness of 100nm. We employ optical lithography and a Buffered Oxide Etch (BOE) of SiO2 followed by anisotropic etching of the substrate silicon using TMAH solution and finally removing SiO2. The electron field emission from the surface of the membrane is traced in the IV characteristics at room temperature. The membrane is then applied for detection of the large ionized proteins using time-of-flight mass spectrometry. Ion detection is demonstrated in our nanomembrane MALDI-TOF analysis of Insulin (5,735 Da). That is when the ions with a large kinetic energy bombard the nanomembrane, their energy is thermalized upon impact into phonons. The phonons give a thermal energy to the electrons with the membrane, which are then excited to higher energetic states. Given an extraction voltage this leads to electron field emission from the membrane which we labeled phonon-assisted field emission (PAFE). In other words, the MALDI mass spectra are obtained by exploiting ballistic phonon propagation and quasi-diffusive phonon propagation.

  17. Femtosecond melting and ablation of semiconductors studied with time of flight mass spectroscopy

    NASA Astrophysics Data System (ADS)

    Cavalleri, Andrea; Sokolowski-Tinten, Klaus; Bialkowski, Joerg; Schreiner, Michaela; von der Linde, Dietrich

    1999-03-01

    Using time-of-flight mass spectroscopy, we have investigated melting and ablation of gallium arsenide and silicon irradiated by femtosecond pulses. Below the ablation threshold the maximum surface temperature is obtained from the collisionless time-of-flight distributions of evaporated or sublimated particles. At the melting threshold, we estimate a temperature for the silicon surface which is approximately 500 K higher than the equilibrium melting temperature. In the fluence regime where melting is known to be a nonthermal process, we measure maximum surface temperatures in excess of 2500 K for both silicon and gallium arsenide, indicating rapid thermalization after nonthermal melting. At the ablation threshold, we estimated for both materials surface temperatures between 3000 and 4000 K. We observed a clear threshold-like effect in the number of detected particles, indicating the occurrence of a bulk effect. The flow parameters above the ablation threshold are discussed and compared to the different models of collisional expansion. For Fabl2Fabl, we find evidence that expansion takes place at temperatures that are higher than the critical temperature. Plasma formation appears only at fluences above 1 J/cm2 (F>5Fabl).

  18. The multipurpose time-of-flight neutron reflectometer “Platypus” at Australia's OPAL reactor

    NASA Astrophysics Data System (ADS)

    James, M.; Nelson, A.; Holt, S. A.; Saerbeck, T.; Hamilton, W. A.; Klose, F.

    2011-03-01

    In this manuscript we describe the major components of the Platypus time-of-flight neutron reflectometer at the 20 MW OPAL reactor in Sydney, Australia. Platypus is a multipurpose spectrometer for the characterisation of solid thin films, materials adsorbed at the solid-liquid interface and free-liquid surfaces. It also has the capacity to study magnetic thin films using spin-polarised neutrons. Platypus utilises a white neutron beam ( λ=2-20 Å) that is pulsed using boron-coated disc chopper pairs; thus providing the capacity to tailor the wavelength resolution of the pulses to suit the system under investigation. Supermirror optical components are used to focus, deflect or spin-polarise the broad bandwidth neutron beams, and typical incident spectra are presented for each configuration. A series of neutron reflectivity datasets are presented, indicating the quality and flexibility of this spectrometer. Minimum reflectivity values of <10 -7 are observed; while maximum thickness values of 325 nm have been measured for single-component films and 483 nm for a multilayer system. Off-specular measurements have also been made to investigate in-plane features as opposed to those normal to the sample surface. Finally, the first published studies conducted using the Platypus time-of-flight neutron reflectometer are presented.

  19. Time-of-Flight Polarized Neutron Reflectometry on PLATYPUS: Status and Future Developments

    NASA Astrophysics Data System (ADS)

    Saerbeck, T.; Cortie, D. L.; Brück, S.; Bertinshaw, J.; Holt, S. A.; Nelson, A.; James, M.; Lee, W. T.; Klose, F.

    Time-of-flight (ToF) polarized neutron reflectometry enables the detailed investigation of depth-resolved magnetic structures in thin film and multilayer magnetic systems. The general advantage of the time-of-flight mode of operation over monochromatic instruments is a decoupling of spectral shape and polarization of the neutron beam with variable resolution. Thus, a wide Q-range can be investigated using a single angle of incidence, with resolution and flux well-adjusted to the experimental requirement. Our paper reviews the current status of the polarization equipment of the ToF reflectometer PLATYPUS and presents first results obtained on stratified Ni80Fe20/α-Fe2O3 films, revealing the distribution of magnetic moments in an exchange bias system. An outlook on the future development of the PLATYPUS polarization system towards the implementation of a polarized 3He cell is presented and discussed with respect to the efficiency and high Q-coverage up to 1 Å-1 and 0.15 Å-1 in the vertical and lateral momentum transfer, respectively.

  20. Absolutely referenced distance measurement by combination of time-of-flight and digital holographic methods

    NASA Astrophysics Data System (ADS)

    Fratz, Markus; Weimann, Claudius; Wölfelschneider, Harald; Koos, Christian; Höfler, Heinrich

    2014-03-01

    We present a novel optical system for distance measurement based on the combination of optical time-of-flight metrology and digital holography. In addition absolute calibration of the measurement results is performed by a sideband modulation technique. For the time-of-flight technique a diode laser (1470 nm) is modulated sinusoidally (128 MHz). The light reflected and scattered by an object is detected by an avalanche-photo-diode. The phase difference between the sent and detected modulation is a measure for the distance between the sensor and the object. This allows for distance measurements up to 1.17 m with resolutions of ~2 mm. The interferometric setup uses 4 whispering-gallery-mode lasers to perform multiwavelengths-holographic distance measurements. The four wavelengths span the range from 1547 nm to 1554 nm. The unambiguous measurement measurement-range of the interferometric setup is approx. 7 mm while resolutions of 0.6 μm are observed. Both setups are integrated into one setup and perform measurements synchronously. Exact knowledge of the frequency differences of hundreds of GHz between the four lasers is crucial for the interferometric fine scale measurement. For this aim the light of the lasers is phase-modulated with frequencies of 36 GHz and 40 GHz to produce optical sidebands of higher order, thus generating beat signals in the hundreds-of-MHz regime, which can be measured electronically. The setup shows a way to measure distances in the meter range with sub-micron resolution.

  1. TOFPET 2: A high-performance circuit for PET time-of-flight

    NASA Astrophysics Data System (ADS)

    Di Francesco, Agostino; Bugalho, Ricardo; Oliveira, Luis; Rivetti, Angelo; Rolo, Manuel; Silva, Jose C.; Varela, Joao

    2016-07-01

    We present a readout and digitization ASIC featuring low-noise and low-power for time-of flight (TOF) applications using SiPMs. The circuit is designed in standard CMOS 110 nm technology, has 64 independent channels and is optimized for time-of-flight measurement in Positron Emission Tomography (TOF-PET). The input amplifier is a low impedance current conveyor based on a regulated common-gate topology. Each channel has quad-buffered analogue interpolation TDCs (time binning 20 ps) and charge integration ADCs with linear response at full scale (1500 pC). The signal amplitude can also be derived from the measurement of time-over-threshold (ToT). Simulation results show that for a single photo-electron signal with charge 200 (550) fC generated by a SiPM with (320 pF) capacitance the circuit has 24 (30) dB SNR, 75 (39) ps r.m.s. resolution, and 4 (8) mW power consumption. The event rate is 600 kHz per channel, with up to 2 MHz dark counts rejection.

  2. Breath Analysis Using a Time-of-Flight Camera and Pressure Belts.

    PubMed

    Zalud, Ludek; Kotova, Marketa; Kocmanová, Petra; Dobsak, Petr; Kolarova, Jana

    2016-06-01

    The proper way of breathing is important for everyone. Healthy people often do not follow respiration until breathing problems start-during stress or during sport activity in physiological cases. More serious cases are stroke, injury, or surgery of the chest and others. So, learning to breathe correctly and/or breathing diagnosis is considerable for many reasons. Two novel methods of breath analysis suitable for diagnostics and rehabilitation are presented. The first technique utilizes pressure belts fastened to the patient's belly and chest, and the second method relies on a SwissRanger SR-4000 time-of-flight camera. The measurement principles are described together with the advantages and disadvantages of the applied techniques. The SwissRanger camera depth calibration is proposed to facilitate better results during the breath analysis. The methods are tested on a group of students to provide a comparison of their individual performances. As it was demonstrated, presented methods proved to work reliably. The method based on time-of-flight camera seems to be more suitable for diagnosis, while the method based on pressure belts is more suitable for rehabilitation and biofeedback applications. PMID:26527126

  3. Resolving multiple propagation paths in time of flight range cameras using direct and global separation methods

    NASA Astrophysics Data System (ADS)

    Whyte, Refael; Streeter, Lee; Cree, Michael J.; Dorrington, Adrian A.

    2015-11-01

    Time of flight (ToF) range cameras illuminate the scene with an amplitude-modulated continuous wave light source and measure the returning modulation envelopes: phase and amplitude. The phase change of the modulation envelope encodes the distance travelled. This technology suffers from measurement errors caused by multiple propagation paths from the light source to the receiving pixel. The multiple paths can be represented as the summation of a direct return, which is the return from the shortest path length, and a global return, which includes all other returns. We develop the use of a sinusoidal pattern from which a closed form solution for the direct and global returns can be computed in nine frames with the constraint that the global return is a spatially lower frequency than the illuminated pattern. In a demonstration on a scene constructed to have strong multipath interference, we find the direct return is not significantly different from the ground truth in 33/136 pixels tested; where for the full-field measurement, it is significantly different for every pixel tested. The variance in the estimated direct phase and amplitude increases by a factor of eight compared with the standard time of flight range camera technique.

  4. Codif: A 3-d Plasma Analyzer With Time-of-flight Mass Discrimination

    NASA Astrophysics Data System (ADS)

    Klecker, B.; Möbius, E.; Kistler, L. M.; Popecki, M. A.; Sauvaud, J.-A.; Reme, H.; Korth, A.; McFadden, J. P.; McCarthy, M. P.; Balsiger, H.

    The development of CODIF (COmposition and DIstribution Function Analyzer) for the CLUSTER mission started in 1988, shortly after the pioneering application of the secondary-electron-emission time-of-flight technique on several missions, includ- ing AMPTE and Giotto. CODIF consists of a toroidal top-hat electrostatic analyzer (ESA), subdivided into 2 halves with geometric factors different by a factor of 100 to cope with the large dynamic range of ion fluxes in the Earth's magnetosphere. Post acceleration of the incoming ions by up to 20 kV, and a time-of-flight mass spectro- graph provide velocity measurements from eV (spacecraft potential) to 40 keV/e and, together with the E/q measurement of the ESA system, a resolution sufficient to sep- arate the most abundant ions H+, He2+, He+, and O+ by onboard analysis. Similar versions of CODIF have now been successfully flown onboard FAST, Equator-S, and CLUSTER-II. The CODIF sensor concept presently serves also as the basis for a new development for the Plasma and Suprathermal Ion Composition (PLASTIC) sensor onboard STEREO. We will discuss the in-flight performance of the CODIF sensor using recent measurements in various regions of the Earth's magnetosphere.

  5. Unenhanced Time-of-Flight MR Angiography versus Gadolinium-Enhanced Time-of-Flight MR Angiography in the Follow-Up of Coil-Embolized Aneurysms.

    PubMed

    Behme, D; Malinova, V; Kallenberg, K; Knauth, M; Mohr, A

    2016-09-01

    Background and Purpose Coil embolization of ruptured and unruptured aneurysms has emerged as a widely accepted alternative to clipping. Unfortunately, coil-embolized aneurysms need a long-term imaging follow-up to confirm the stability of the occlusion status. We investigated whether contrast-enhanced time-of-flight (ToF) magnetic resonance angiography (MRA) (gadolinium [Gd]-ToF) provides any diagnostic benefit over conventional ToF MRA (nonenhanced [NE]-ToF) in this context. Material and Methods From October 2013 to January 2015, all patients who were regularly scheduled for their follow-up after coil embolization were examined with Gd-ToF and NE-ToF angiography. The general visibility of the occlusion result was compared between the two MRAs as well as with the last digital subtraction angiography (DSA) available. Subgroups of interest (follow-up after stent-assisted coil embolization, cases with already known aneurysm remnants) were also analyzed. Results A total of 70 patients (44 female) harboring 74 treated aneurysms were examined. The reproducibility of the DSA result in terms of therapeutic relevance was 100%. In 10 of 74 cases (14%), the aneurysm status was more difficult to judge in the NE-ToF images (p = 0.02), and the visualization of small vessels was significantly better in the Gd-ToF (p = 0.003). NE-ToF did not fail to show any aneurysm remnants but were more difficult to depict in 35% of the cases (p = 0.09). Regarding the aneurysms that were coiled with stent assistance, there was no significant difference in terms of the visualization (p = 0.1). Conclusion Gd-ToF angiography is in general not superior to NE- ToF for the follow-up of coil-embolized aneurysms. PMID:27168318

  6. Time-frequency energy density precipitation method for time-of-flight extraction of narrowband Lamb wave detection signals

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Huang, S. L.; Wang, S.; Zhao, W.

    2016-05-01

    The time-of-flight of the Lamb wave provides an important basis for defect evaluation in metal plates and is the input signal for Lamb wave tomographic imaging. However, the time-of-flight can be difficult to acquire because of the Lamb wave dispersion characteristics. This work proposes a time-frequency energy density precipitation method to accurately extract the time-of-flight of narrowband Lamb wave detection signals in metal plates. In the proposed method, a discrete short-time Fourier transform is performed on the narrowband Lamb wave detection signals to obtain the corresponding discrete time-frequency energy density distribution. The energy density values at the center frequency for all discrete time points are then calculated by linear interpolation. Next, the time-domain energy density curve focused on that center frequency is precipitated by least squares fitting of the calculated energy density values. Finally, the peak times of the energy density curve obtained relative to the initial pulse signal are extracted as the time-of-flight for the narrowband Lamb wave detection signals. An experimental platform is established for time-of-flight extraction of narrowband Lamb wave detection signals, and sensitivity analysis of the proposed time-frequency energy density precipitation method is performed in terms of propagation distance, dispersion characteristics, center frequency, and plate thickness. For comparison, the widely used Hilbert-Huang transform method is also implemented for time-of-flight extraction. The results show that the time-frequency energy density precipitation method can accurately extract the time-of-flight with relative error of <1% and thus can act as a universal time-of-flight extraction method for narrowband Lamb wave detection signals.

  7. Deuterated-xylene (xylene-d10; EJ301D): A new, improved deuterated liquid scintillator for neutron energy measurements without time-of-flight

    NASA Astrophysics Data System (ADS)

    Becchetti, F. D.; Raymond, R. S.; Torres-Isea, R. O.; Di Fulvio, A.; Clarke, S. D.; Pozzi, S. A.; Febbraro, M.

    2016-06-01

    In conjunction with Eljen Technology, Inc. (Sweetwater,TX) we have designed, constructed, and evaluated a 3 in. ×3 in. deuterated-xylene organic liquid scintillator (C8D10; EJ301D) as a fast neutron detector. Similar to deuterated benzene (C6D6; NE230, BC537, and EJ315) this scintillator can provide good pulse-shape discrimination between neutrons and gamma rays, has good timing characteristics, and can provide a light spectrum with peaks corresponding to discrete neutron energy groups up to ca. 20 MeV. Unlike benzene-based detectors, deuterated xylene is less volatile, less toxic, is not known to be carcinogenic, has a higher flashpoint, and hence is much safer for many applications. In addition EJ301D can provide slightly more light output and better PSD than deuterated-benzene scintillators. We show that, as with deuterated-benzene scintillators, the light-response spectra can be unfolded to provide useable neutron energy spectra without need for time-of-flight (ToF). An array of these detectors arranged at many angles close to a reaction target can be much more effective (×10 to ×100 or more) than an array of long-path ToF detectors which must utilize a narrowly-bunched and pulse-selected beam. As we demonstrate using a small Van de Graaff accelerator, measurements can thus be performed when a bunched and pulse-selected beam (as needed for time-of-flight) is not available.

  8. DDL, the ALICE data transmission protocol and its evolution from 2 to 6 Gb/s

    NASA Astrophysics Data System (ADS)

    Carena, F.; Carena, W.; Chibante Barroso, V.; Costa, F.; Chapeland, S.; Delort, C.; Dénes, E.; Divià, R.; Fuchs, U.; Grigore, A.; Ionita, C.; Kiss, T.; Simonetti, G.; Soós, C.; Telesca, A.; Vande Vyvre, P.; Von Haller, B.

    2015-04-01

    ALICE (A Large Ion Collider Experiment) is the detector system at the LHC (Large Hadron Collider) that studies the behaviour of strongly interacting matter and the quark gluon plasma. The information sent by the sub-detectors composing ALICE are read out by DATE (Data Acquisition and Test Environment), the ALICE data acquisition software, using hundreds of multi-mode optical links called DDL (Detector Data Link). To cope with the higher luminosity of the LHC, the bandwidth of the DDL links will be upgraded in 2015. This paper will describe the evolution of the DDL protocol from 2 to 6 Gbit/s.

  9. The ALICE experiment at the CERN LHC

    NASA Astrophysics Data System (ADS)

    ALICE Collaboration; Aamodt, K.; Abrahantes Quintana, A.; Achenbach, R.; Acounis, S.; Adamová, D.; Adler, C.; Aggarwal, M.; Agnese, F.; Aglieri Rinella, G.; Ahammed, Z.; Ahmad, A.; Ahmad, N.; Ahmad, S.; Akindinov, A.; Akishin, P.; Aleksandrov, D.; Alessandro, B.; Alfaro, R.; Alfarone, G.; Alici, A.; Alme, J.; Alt, T.; Altinpinar, S.; Amend, W.; Andrei, C.; Andres, Y.; Andronic, A.; Anelli, G.; Anfreville, M.; Angelov, V.; Anzo, A.; Anson, C.; Anticić, T.; Antonenko, V.; Antonczyk, D.; Antinori, F.; Antinori, S.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Aprodu, V.; Arba, M.; Arcelli, S.; Argentieri, A.; Armesto, N.; Arnaldi, R.; Arefiev, A.; Arsene, I.; Asryan, A.; Augustinus, A.; Awes, T. C.; Äysto, J.; Danish Azmi, M.; Bablock, S.; Badalà, A.; Badyal, S. K.; Baechler, J.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baldit, A.; Bán, J.; Barbera, R.; Barberis, P.-L.; Barbet, J. M.; Barnäfoldi, G.; Barret, V.; Bartke, J.; Bartos, D.; Basile, M.; Basmanov, V.; Bastid, N.; Batigne, G.; Batyunya, B.; Baudot, J.; Baumann, C.; Bearden, I.; Becker, B.; Belikov, J.; Bellwied, R.; Belmont-Moreno, E.; Belogianni, A.; Belyaev, S.; Benato, A.; Beney, J. L.; Benhabib, L.; Benotto, F.; Beolé, S.; Berceanu, I.; Bercuci, A.; Berdermann, E.; Berdnikov, Y.; Bernard, C.; Berny, R.; Berst, J. D.; Bertelsen, H.; Betev, L.; Bhasin, A.; Baskar, P.; Bhati, A.; Bianchi, N.; Bielčik, J.; Bielčiková, J.; Bimbot, L.; Blanchard, G.; Blanco, F.; Blanco, F.; Blau, D.; Blume, C.; Blyth, S.; Boccioli, M.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Boldizsár, L.; Bombara, M.; Bombonati, C.; Bondila, M.; Bonnet, D.; Bonvicini, V.; Borel, H.; Borotto, F.; Borshchov, V.; Bortoli, Y.; Borysov, O.; Bose, S.; Bosisio, L.; Botje, M.; Böttger, S.; Bourdaud, G.; Bourrion, O.; Bouvier, S.; Braem, A.; Braun, M.; Braun-Munzinger, P.; Bravina, L.; Bregant, M.; Bruckner, G.; Brun, R.; Bruna, E.; Brunasso, O.; Bruno, G. E.; Bucher, D.; Budilov, V.; Budnikov, D.; Buesching, H.; Buncic, P.; Burns, M.; Burachas, S.; Busch, O.; Bushop, J.; Cai, X.; Caines, H.; Calaon, F.; Caldogno, M.; Cali, I.; Camerini, P.; Campagnolo, R.; Campbell, M.; Cao, X.; Capitani, G. P.; Romeo, G. Cara; Cardenas-Montes, M.; Carduner, H.; Carena, F.; Carena, W.; Cariola, P.; Carminati, F.; Casado, J.; Casanova Diaz, A.; Caselle, M.; Castillo Castellanos, J.; Castor, J.; Catanescu, V.; Cattaruzza, E.; Cavazza, D.; Cerello, P.; Ceresa, S.; Černý, V.; Chambert, V.; Chapeland, S.; Charpy, A.; Charrier, D.; Chartoire, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chepurnov, V.; Chernenko, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chochula, P.; Chiavassa, E.; Chibante Barroso, V.; Choi, J.; Christakoglou, P.; Christiansen, P.; Christensen, C.; Chykalov, O. A.; Cicalo, C.; Cifarelli-Strolin, L.; Ciobanu, M.; Cindolo, F.; Cirstoiu, C.; Clausse, O.; Cleymans, J.; Cobanoglu, O.; Coffin, J.-P.; Coli, S.; Colla, A.; Colledani, C.; Combaret, C.; Combet, M.; Comets, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Contin, G.; Contreras, J.; Cormier, T.; Corsi, F.; Cortese, P.; Costa, F.; Crescio, E.; Crochet, P.; Cuautle, E.; Cussonneau, J.; Dahlinger, M.; Dainese, A.; Dalsgaard, H. H.; Daniel, L.; Das, I.; Das, T.; Dash, A.; Da Silva, R.; Davenport, M.; Daues, H.; DeCaro, A.; de Cataldo, G.; DeCuveland, J.; DeFalco, A.; de Gaspari, M.; de Girolamo, P.; de Groot, J.; DeGruttola, D.; DeHaas, A.; DeMarco, N.; DePasquale, S.; DeRemigis, P.; de Vaux, D.; Decock, G.; Delagrange, H.; DelFranco, M.; Dellacasa, G.; Dell'Olio, C.; Dell'Olio, D.; Deloff, A.; Demanov, V.; Dénes, E.; D'Erasmo, G.; Derkach, D.; Devaux, A.; Di Bari, D.; Di Bartelomen, A.; Di Giglio, C.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Dialinas, M.; Diaz, L.; Díaz Valdes, R.; Dietel, T.; Dima, R.; Ding, H.; Dinca, C.; Divià, R.; Dobretsov, V.; Dobrin, A.; Doenigus, B.; Dobrowolski, T.; Domínguez, I.; Dorn, M.; Drouet, S.; Dubey, A. E.; Ducroux, L.; Dumitrache, F.; Dumonteil, E.; Dupieux, P.; Duta, V.; Dutta Majumdar, A.; Dutta Majumdar, M.; Dyhre, Th; Efimov, L.; Efremov, A.; Elia, D.; Emschermann, D.; Engster, C.; Enokizono, A.; Espagnon, B.; Estienne, M.; Evangelista, A.; Evans, D.; Evrard, S.; Fabjan, C. W.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Farano, R.; Fearick, R.; Fedorov, O.; Fekete, V.; Felea, D.; Feofilov, G.; Férnandez Téllez, A.; Ferretti, A.; Fichera, F.; Filchagin, S.; Filoni, E.; Finck, C.; Fini, R.; Fiore, E. M.; Flierl, D.; Floris, M.; Fodor, Z.; Foka, Y.; Fokin, S.; Force, P.; Formenti, F.; Fragiacomo, E.; Fragkiadakis, M.; Fraissard, D.; Franco, A.; Franco, M.; Frankenfeld, U.; Fratino, U.; Fresneau, S.; Frolov, A.; Fuchs, U.; Fujita, J.; Furget, C.; Furini, M.; Fusco Girard, M.; Gaardhøje, J.-J.; Gabrielli, A.; Gadrat, S.; Gagliardi, M.; Gago, A.; Gaido, L.; Gallas Torreira, A.; Gallio, M.; Gandolfi, E.; Ganoti, P.; Ganti, M.; Garabatos, J.; Garcia Lopez, A.; Garizzo, L.; Gaudichet, L.; Gemme, R.; Germain, M.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Giolu, G.; Giraudo, G.; Giubellino, P.; Glasow, R.; Glässel, P.; Ferreiro, E. G.; Gonzalez Gutierrez, C.; Gonzales-Trueba, L. H.; Gorbunov, S.; Gorbunov, Y.; Gos, H.; Gosset, J.; Gotovac, S.; Gottschlag, H.; Gottschalk, D.; Grabski, V.; Grassi, T.; Gray, H.; Grebenyuk, O.; Grebieszkow, K.; Gregory, C.; Grigoras, C.; Grion, N.; Grigoriev, V.; Grigoryan, A.; Grigoryan, C.; Grigoryan, S.; Grishuk, Y.; Gros, P.; Grosse-Oetringhaus, J.; Grossiord, J.-Y.; Grosso, R.; Grynyov, B.; Guarnaccia, C.; Guber, F.; Guerin, F.; Guernane, R.; Guerzoni, M.; Guichard, A.; Guida, M.; Guilloux, G.; Gulkanyan, H.; Gulbrandsen, K.; Gunji, T.; Gupta, A.; Gupta, V.; Gustafsson, H.-A.; Gutbrod, H.; Hadjidakis, C.; Haiduc, M.; Hamar, G.; Hamagaki, H.; Hamblen, J.; Hansen, J. C.; Hardy, P.; Hatzifotiadou, D.; Harris, J. W.; Hartig, M.; Harutyunyan, A.; Hayrapetyan, A.; Hasch, D.; Hasegan, D.; Hehner, J.; Heine, N.; Heinz, M.; Helstrup, H.; Herghelegiu, A.; Herlant, S.; Herrera Corral, G.; Herrmann, N.; Hetland, K.; Hille, P.; Hinke, H.; Hippolyte, B.; Hoch, M.; Hoebbel, H.; Hoedlmoser, H.; Horaguchi, T.; Horner, M.; Hristov, P.; Hřivnáčová, I.; Hu, S.; Guo, C. Hu; Humanic, T.; Hurtado, A.; Hwang, D. S.; Ianigro, J. C.; Idzik, M.; Igolkin, S.; Ilkaev, R.; Ilkiv, I.; Imhoff, M.; Innocenti, P. G.; Ionescu, E.; Ippolitov, M.; Irfan, M.; Insa, C.; Inuzuka, M.; Ivan, C.; Ivanov, A.; Ivanov, M.; Ivanov, V.; Jacobs, P.; Jacholkowski, A.; Jančurová, L.; Janik, R.; Jasper, M.; Jena, C.; Jirden, L.; Johnson, D. P.; Jones, G. T.; Jorgensen, C.; Jouve, F.; Jovanović, P.; Junique, A.; Jusko, A.; Jung, H.; Jung, W.; Kadija, K.; Kamal, A.; Kamermans, R.; Kapusta, S.; Kaidalov, A.; Kakoyan, V.; Kalcher, S.; Kang, E.; Kapitan, J.; Kaplin, V.; Karadzhev, K.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Karpio, K.; Kazantsev, A.; Kebschull, U.; Keidel, R.; Mohsin Khan, M.; Khanzadeev, A.; Kharlov, Y.; Kikola, D.; Kileng, B.; Kim, D.; Kim, D. S.; Kim, D. W.; Kim, H. N.; Kim, J. S.; Kim, S.; Kinson, J. B.; Kiprich, S. K.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, T.; Kiworra, V.; Klay, J.; Klein Bösing, C.; Kliemant, M.; Klimov, A.; Klovning, A.; Kluge, A.; Kluit, R.; Kniege, S.; Kolevatov, R.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kornas, E.; Koshurnikov, E.; Kotov, I.; Kour, R.; Kowalski, M.; Kox, S.; Kozlov, K.; Králik, I.; Kramer, F.; Kraus, I.; Kravčáková, A.; Krawutschke, T.; Krivda, M.; Kryshen, E.; Kucheriaev, Y.; Kugler, A.; Kuhn, C.; Kuijer, P.; Kumar, L.; Kumar, N.; Kumpumaeki, P.; Kurepin, A.; Kurepin, A. N.; Kushpil, S.; Kushpil, V.; Kutovsky, M.; Kvaerno, H.; Kweon, M.; Labbé, J.-C.; Lackner, F.; Ladron de Guevara, P.; Lafage, V.; La Rocca, P.; Lamont, M.; Lara, C.; Larsen, D. T.; Laurenti, G.; Lazzeroni, C.; LeBornec, Y.; LeBris, N.; LeGailliard, C.; Lebedev, V.; Lecoq, J.; Lee, K. S.; Lee, S. C.; Lefévre, F.; Legrand, I.; Lehmann, T.; Leistam, L.; Lenoir, P.; Lenti, V.; Leon, H.; Monzon, I. Leon; Lévai, P.; Li, Q.; Li, X.; Librizzi, F.; Lietava, R.; Lindegaard, N.; Lindenstruth, V.; Lippmann, C.; Lisa, M.; Listratenko, O. M.; Littel, F.; Liu, Y.; Lo, J.; Lobanov, V.; Loginov, V.; López Noriega, M.; López-Ramírez, R.; López Torres, E.; Lorenzo, P. M.; Løvhøiden, G.; Lu, S.; Ludolphs, W.; Lunardon, M.; Luquin, L.; Lusso, S.; Lutz, J.-R.; Luvisetto, M.; Lyapin, V.; Maevskaya, A.; Magureanu, C.; Mahajan, A.; Majahan, S.; Mahmoud, T.; Mairani, A.; Mahapatra, D.; Makarov, A.; Makhlyueva, I.; Malek, M.; Malkiewicz, T.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manea, C.; Mangotra, L. K.; Maniero, D.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Marcel, A.; Marchini, S.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Marin, A.; Marin, J.-C.; Marras, D.; Martinengo, P.; Martínez, M. I.; Martinez-Davalos, A.; Martínez Garcia, G.; Martini, S.; Marzari Chiesa, A.; Marzocca, C.; Masciocchi, S.; Masera, M.; Masetti, M.; Maslov, N. I.; Masoni, A.; Massera, F.; Mast, M.; Mastroserio, A.; Matthews, Z. L.; Mayer, B.; Mazza, G.; Mazzaro, M. D.; Mazzoni, A.; Meddi, F.; Meleshko, E.; Menchaca-Rocha, A.; Meneghini, S.; Meoni, M.; Mercado Perez, J.; Mereu, P.; Meunier, O.; Miake, Y.; Michalon, A.; Michinelli, R.; Miftakhov, N.; Mignone, M.; Mikhailov, K.; Milosevic, J.; Minaev, Y.; Minafra, F.; Mischke, A.; Miśkowiec, D.; Mitsyn, V.; Mitu, C.; Mohanty, B.; Moisa, D.; Molnar, L.; Mondal, M.; Mondal, N.; Montaño Zetina, L.; Monteno, M.; Morando, M.; Morel, M.; Moretto, S.; Morhardt, Th; Morsch, A.; Moukhanova, T.; Mucchi, M.; Muccifora, V.; Mudnic, E.; Müller, H.; Müller, W.; Munoz, J.; Mura, D.; Musa, L.; Muraz, J. F.; Musso, A.; Nania, R.; Nandi, B.; Nappi, E.; Navach, F.; Navin, S.; Nayak, T.; Nazarenko, S.; Nazarov, G.; Nellen, L.; Nendaz, F.; Nianine, A.; Nicassio, M.; Nielsen, B. S.; Nikolaev, S.; Nikolic, V.; Nikulin, S.; Nikulin, V.; Nilsen, B.; Nitti, M.; Noferini, F.; Nomokonov, P.; Nooren, G.; Noto, F.; Nouais, D.; Nyiri, A.; Nystrand, J.; Odyniec, G.; Oeschler, H.; Oinonen, M.; Oldenburg, M.; Oleks, I.; Olsen, E. K.; Onuchin, V.; Oppedisano, C.; Orsini, F.; Ortiz-Velázquez, A.; Oskamp, C.; Oskarsson, A.; Osmic, F.; Österman, L.; Otterlund, I.; Ovrebekk, G.; Oyama, K.; Pachr, M.; Pagano, P.; Paić, G.; Pajares, C.; Pal, S.; Pal, S.; Pálla, G.; Palmeri, A.; Pancaldi, G.; Panse, R.; Pantaleo, A.; Pappalardo, G. S.; Pastirčák, B.; Pastore, C.; Patarakin, O.; Paticchio, V.; Patimo, G.; Pavlinov, A.; Pawlak, T.; Peitzmann, T.; Pénichot, Y.; Pepato, A.; Pereira, H.; Peresunko, D.; Perez, C.; Perez Griffo, J.; Perini, D.; Perrino, D.; Peryt, W.; Pesci, A.; Peskov, V.; Pestov, Y.; Peters, A. J.; Petráček, V.; Petridis, A.; Petris, M.; Petrov, V.; Petrov, V.; Petrovici, M.; Peyré, J.; Piano, S.; Piccotti, A.; Pichot, P.; Piemonte, C.; Pikna, M.; Pilastrini, R.; Pillot, P.; Pinazza, O.; Pini, B.; Pinsky, L.; Pinto Morais, V.; Pismennaya, V.; Piuz, F.; Platt, R.; Ploskon, M.; Plumeri, S.; Pluta, J.; Pocheptsov, T.; Podesta, P.; Poggio, F.; Poghosyan, M.; Poghosyan, T.; Polák, K.; Polichtchouk, B.; Polozov, P.; Polyakov, V.; Pommeresch, B.; Pompei, F.; Pop, A.; Popescu, S.; Posa, F.; Pospíšil, V.; Potukuchi, B.; Pouthas, J.; Prasad, S.; Preghenella, R.; Prino, F.; Prodan, L.; Prono, G.; Protsenko, M. A.; Pruneau, C. A.; Przybyla, A.; Pshenichnov, I.; Puddu, G.; Pujahari, P.; Pulvirenti, A.; Punin, A.; Punin, V.; Putschke, J.; Quartieri, J.; Quercigh, E.; Rachevskaya, I.; Rachevski, A.; Rademakers, A.; Radomski, S.; Radu, A.; Rak, J.; Ramello, L.; Raniwala, R.; Raniwala, S.; Rasmussen, O. B.; Rasson, J.; Razin, V.; Read, K.; Real, J.; Redlich, K.; Reichling, C.; Renard, C.; Renault, G.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Revol, J.-P.; Reygers, K.; Ricaud, H.; Riccati, L.; Ricci, R. A.; Richter, M.; Riedler, P.; Rigalleau, L. M.; Riggi, F.; Riegler, W.; Rindel, E.; Riso, J.; Rivetti, A.; Rizzi, M.; Rizzi, V.; Rodriguez Cahuantzi, M.; Røed, K.; Röhrich, D.; Román-López, S.; Romanato, M.; Romita, R.; Ronchetti, F.; Rosinsky, P.; Rosnet, P.; Rossegger, S.; Rossi, A.; Rostchin, V.; Rotondo, F.; Roukoutakis, F.; Rousseau, S.; Roy, C.; Roy, D.; Roy, P.; Royer, L.; Rubin, G.; Rubio, A.; Rui, R.; Rusanov, I.; Russo, G.; Ruuskanen, V.; Ryabinkin, E.; Rybicki, A.; Sadovsky, S.; Šafařík, K.; Sahoo, R.; Saini, J.; Saiz, P.; Salur, S.; Sambyal, S.; Samsonov, V.; Šándor, L.; Sandoval, A.; Sann, H.; Santiard, J.-C.; Santo, R.; Santoro, R.; Sargsyan, G.; Saturnini, P.; Scapparone, E.; Scarlassara, F.; Schackert, B.; Schiaua, C.; Schicker, R.; Schioler, T.; Schippers, J. D.; Schmidt, C.; Schmidt, H.; Schneider, R.; Schossmaier, K.; Schukraft, J.; Schutz, Y.; Schwarz, K.; Schweda, K.; Schyns, E.; Scioli, G.; Scomparin, E.; Snow, H.; Sedykh, S.; Segato, G.; Sellitto, S.; Semeria, F.; Senyukov, S.; Seppänen, H.; Serci, S.; Serkin, L.; Serra, S.; Sesselmann, T.; Sevcenco, A.; Sgura, I.; Shabratova, G.; Shahoyan, R.; Sharkov, E.; Sharma, S.; Shigaki, K.; Shileev, K.; Shukla, P.; Shurygin, A.; Shurygina, M.; Sibiriak, Y.; Siddi, E.; Siemiarczuk, T.; Sigward, M. H.; Silenzi, A.; Silvermyr, D.; Silvestri, R.; Simili, E.; Simion, V.; Simon, R.; Simonetti, L.; Singaraju, R.; Singhal, V.; Sinha, B.; Sinha, T.; Siska, M.; Sitár, B.; Sitta, M.; Skaali, B.; Skowronski, P.; Slodkowski, M.; Smirnov, N.; Smykov, L.; Snellings, R.; Snoeys, W.; Soegaard, C.; Soerensen, J.; Sokolov, O.; Soldatov, A.; Soloviev, A.; Soltveit, H.; Soltz, R.; Sommer, W.; Soos, C.; Soramel, F.; Sorensen, S.; Soyk, D.; Spyropoulou-Stassinaki, M.; Stachel, J.; Staley, F.; Stan, I.; Stavinskiy, A.; Steckert, J.; Stefanini, G.; Stefanek, G.; Steinbeck, T.; Stelzer, H.; Stenlund, E.; Stocco, D.; Stockmeier, M.; Stoicea, G.; Stolpovsky, P.; Strmeň, P.; Stutzmann, J. S.; Su, G.; Sugitate, T.; Šumbera, M.; Suire, C.; Susa, T.; Sushil Kumar, K.; Swoboda, D.; Symons, J.; Szarka, I.; Szostak, A.; Szuba, M.; Szymanski, P.; Tadel, M.; Tagridis, C.; Tan, L.; Tapia Takaki, D.; Taureg, H.; Tauro, A.; Tavlet, M.; Tejeda Munoz, G.; Thäder, J.; Tieulent, R.; Timmer, P.; Tolyhy, T.; Topilskaya, N.; Torcato de Matos, C.; Torii, H.; Toscano, L.; Tosello, F.; Tournaire, A.; Traczyk, T.; Tröger, G.; Tromeur, W.; Truesdale, D.; Trzaska, W.; Tsiledakis, G.; Tsilis, E.; Tsvetkov, A.; Turcato, M.; Turrisi, R.; Tuveri, M.; Tveter, T.; Tydesjo, H.; Tykarski, L.; Tywoniuk, K.; Ugolini, E.; Ullaland, K.; Urbán, J.; Urciuoli, G. M.; Usai, G. L.; Usseglio, M.; Vacchi, A.; Vala, M.; Valiev, F.; Vande Vyvre, P.; Van Den Brink, A.; Van Eijndhoven, N.; Van Der Kolk, N.; van Leeuwen, M.; Vannucci, L.; Vanzetto, S.; Vanuxem, J.-P.; Vargas, M. A.; Varma, R.; Vascotto, A.; Vasiliev, A.; Vassiliou, M.; Vasta, P.; Vechernin, V.; Venaruzzo, M.; Vercellin, E.; Vergara, S.; Verhoeven, W.; Veronese, F.; Vetlitskiy, I.; Vernet, R.; Victorov, V.; Vidak, L.; Viesti, G.; Vikhlyantsev, O.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Viyogi, Y.; Vodopianov, A.; Volpe, G.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Wabnitz, C.; Wagner, V.; Wallet, L.; Wan, R.; Wang, Y.; Wang, Y.; Wheadon, R.; Weis, R.; Wen, Q.; Wessels, J.; Westergaard, J.; Wiechula, J.; Wiesenaecker, A.; Wikne, J.; Wilk, A.; Wilk, G.; Williams, C.; Willis, N.; Windelband, B.; Witt, R.; Woehri, H.; Wyllie, K.; Xu, C.; Yang, C.; Yang, H.; Yermia, F.; Yin, Z.; Yin, Z.; Ky, B. Yun; Yushmanov, I.; Yuting, B.; Zabrodin, E.; Zagato, S.; Zagreev, B.; Zaharia, P.; Zalite, A.; Zampa, G.; Zampolli, C.; Zanevskiy, Y.; Zarochentsev, A.; Zaudtke, O.; Závada, P.; Zbroszczyk, H.; Zepeda, A.; Zeter, V.; Zgura, I.; Zhalov, M.; Zhou, D.; Zhou, S.; Zhu, G.; Zichichi, A.; Zinchenko, A.; Zinovjev, G.; Zoccarato, Y.; Zubarev, A.; Zucchini, A.; Zuffa, M.

    2008-08-01

    ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries. Its overall dimensions are 16 × 16 × 26 m3 with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This

  10. The C-RORC PCIe card and its application in the ALICE and ATLAS experiments

    NASA Astrophysics Data System (ADS)

    Borga, A.; Costa, F.; Crone, G. J.; Engel, H.; Eschweiler, D.; Francis, D.; Green, B.; Joos, M.; Kebschull, U.; Kiss, T.; Kugel, A.; Panduro Vazquez, J. G.; Soos, C.; Teixeira-Dias, P.; Tremblet, L.; Vande Vyvre, P.; Vandelli, W.; Vermeulen, J. C.; Werner, P.; Wickens, F. J.

    2015-02-01

    The ALICE and ATLAS DAQ systems read out detector data via point-to-point serial links into custom hardware modules, the ALICE RORC and ATLAS ROBIN. To meet the increase in operational requirements both experiments are replacing their respective modules with a new common module, the C-RORC. This card, developed by ALICE, implements a PCIe Gen 2 x8 interface and interfaces to twelve optical links via three QSFP transceivers. This paper presents the design of the C-RORC, its performance and its application in the ALICE and ATLAS experiments.

  11. The ALICE Electronic Logbook

    NASA Astrophysics Data System (ADS)

    Altini, V.; Carena, F.; Carena, W.; Chapeland, S.; Chibante Barroso, V.; Costa, F.; Divià, R.; Fuchs, U.; Makhlyueva, I.; Roukoutakis, F.; Schossmaier, K.; Soòs, C.; Vande Vyvre, P.; Von Haller, B.; ALICE Collaboration

    2010-04-01

    All major experiments need tools that provide a way to keep a record of the events and activities, both during commissioning and operations. In ALICE (A Large Ion Collider Experiment) at CERN, this task is performed by the Alice Electronic Logbook (eLogbook), a custom-made application developed and maintained by the Data-Acquisition group (DAQ). Started as a statistics repository, the eLogbook has evolved to become not only a fully functional electronic logbook, but also a massive information repository used to store the conditions and statistics of the several online systems. It's currently used by more than 600 users in 30 different countries and it plays an important role in the daily ALICE collaboration activities. This paper will describe the LAMP (Linux, Apache, MySQL and PHP) based architecture of the eLogbook, the database schema and the relevance of the information stored in the eLogbook to the different ALICE actors, not only for near real time procedures but also for long term data-mining and analysis. It will also present the web interface, including the different used technologies, the implemented security measures and the current main features. Finally it will present the roadmap for the future, including a migration to the web 2.0 paradigm, the handling of the database ever-increasing data volume and the deployment of data-mining tools.

  12. Alice in Debitland.

    ERIC Educational Resources Information Center

    Board of Governors of the Federal Reserve System, Washington, DC.

    Designed for the general public and possibly suitable also for high school economics students, this booklet examines the Electronic Fund Transfer Act (EFT), which protects consumers who use debit cards for the electronic transfer of funds. This commercially adapted version of the character in "Alice in Wonderland," uses a story-teller approach to…

  13. Upgrade of the ALICE Inner Tracking System

    NASA Astrophysics Data System (ADS)

    Kushpil, Svetlana; ALICE Collaboration

    2016-02-01

    ALICE detector was constructed to study the properties of hot and dense hadronic matter formed in relativistic nuclear collisions. During the second long LHC shutdown in 2019-2020, the collaboration plans to upgrade the current vertex detector, the Inner Tracking System (ITS), in order to increase the reconstruction accuracy of secondary vertices and to lower the threshold of particle transverse momentum measurement. The upgrade strategy of ITS is based on the application of new Monolithic Active Pixel Sensors (MAPS) designed in 0.18 μm CMOS technology. The 50 μm thick chip consists of a single silicon die incorporating a 0.18 μm high-resistivity silicon epitaxial layer (sensor active volume) and matrix of charge collection diodes (pixels) with readout electronics. Radiation hardness of the upgraded ITS is one of the crucial moments in the overall performance of the system. A wide set of MAPS structures with different read-out circuits was produced and is being studied by the ALICE collaboration to optimize the pixel sensor functionality. An overview of the ALICE ITS upgrade and the expected performance improvement will be presented together with selected results from a campaign that includes several irradiation and beam tests.

  14. Methodology for the neutron time of flight measurement of 120-GeV proton-induced reactions on a thick copper target

    DOE PAGESBeta

    Sanami, T.; Iwamoto, Y.; Kajimoto, T.; Shigyo, N.; Hagiwara, M.; Lee, H. S.; Ramberg, E.; Coleman, R.; Soha, A.; Jensen, D.; et al

    2011-12-06

    Our methodology for the time-of-flight measurement of the neutron energy spectrum for a high-energy proton-beam-induced reaction was established at the Fermilab Test Beam Facility of the Fermi National Accelerator Laboratory. The 120-GeV proton beam with 3 × 105 protons/spill was prepared for event-by-event counting of incident protons and emitted neutrons for time-of-flight energy determination. An NE213 organic liquid scintillator (12.7 cm in diameter by 12.7 cm in length) was employed with a veto plastic scintillator and a pulse-shape discrimination technique to identify neutrons. Raw waveforms of NE213, veto and beam detectors were recorded to discriminate the effects of multi-proton beammore » events by considering different time windows. The neutron energy spectrum ranging from 10 to 800 MeV was obtained for a 60-cm-long copper target at 90° with respect to the beam axis. Finally our obtained spectrum was consistent with that deduced employing the conventional unfolding technique as well as that obtained in a 40-GeV/c thin-target experiment.« less

  15. Methodology for the neutron time of flight measurement of 120-GeV proton-induced reactions on a thick copper target

    SciTech Connect

    Sanami, T.; Iwamoto, Y.; Kajimoto, T.; Shigyo, N.; Hagiwara, M.; Lee, H. S.; Ramberg, E.; Coleman, R.; Soha, A.; Jensen, D.; Leveling, A.; Mokhov, N. V.; Boehnlein, D.; Vaziri, K.; Ishibashi, K.; Sakamoto, Y.; Nakashima, H.

    2011-12-06

    Our methodology for the time-of-flight measurement of the neutron energy spectrum for a high-energy proton-beam-induced reaction was established at the Fermilab Test Beam Facility of the Fermi National Accelerator Laboratory. The 120-GeV proton beam with 3 × 105 protons/spill was prepared for event-by-event counting of incident protons and emitted neutrons for time-of-flight energy determination. An NE213 organic liquid scintillator (12.7 cm in diameter by 12.7 cm in length) was employed with a veto plastic scintillator and a pulse-shape discrimination technique to identify neutrons. Raw waveforms of NE213, veto and beam detectors were recorded to discriminate the effects of multi-proton beam events by considering different time windows. The neutron energy spectrum ranging from 10 to 800 MeV was obtained for a 60-cm-long copper target at 90° with respect to the beam axis. Finally our obtained spectrum was consistent with that deduced employing the conventional unfolding technique as well as that obtained in a 40-GeV/c thin-target experiment.

  16. Methodology for the neutron time of flight measurement of 120-GeV proton-induced reactions on a thick copper target

    NASA Astrophysics Data System (ADS)

    Sanami, T.; Iwamoto, Y.; Kajimoto, T.; Shigyo, N.; Hagiwara, M.; Lee, H. S.; Ramberg, E.; Coleman, R.; Soha, A.; Jensen, D.; Leveling, A.; Mokhov, N. V.; Boehnlein, D.; Vaziri, K.; Ishibashi, K.; Sakamoto, Y.; Nakashima, H.

    2012-03-01

    A methodology for the time-of-flight measurement of the neutron energy spectrum for a high-energy proton-beam-induced reaction was established at the Fermilab Test Beam Facility of the Fermi National Accelerator Laboratory. The 120-GeV proton beam with 3 × 105 protons/spill was prepared for event-by-event counting of incident protons and emitted neutrons for time-of-flight energy determination. An NE213 organic liquid scintillator (12.7 cm in diameter by 12.7 cm in length) was employed with a veto plastic scintillator and a pulse-shape discrimination technique to identify neutrons. Raw waveforms of NE213, veto and beam detectors were recorded to discriminate the effects of multi-proton beam events by considering different time windows. The neutron energy spectrum ranging from 10 to 800 MeV was obtained for a 60-cm-long copper target at 90° with respect to the beam axis. The obtained spectrum was consistent with that deduced employing the conventional unfolding technique as well as that obtained in a 40-GeV/c thin-target experiment.

  17. Light output function and assembly of the time-of-flight enhanced diagnostics neutron spectrometer plastic scintillators for background reduction by double kinematic selection at EAST

    SciTech Connect

    Peng, X. Y.; Chen, Z. J.; Zhang, X.; Hu, Z. M.; Du, T. F.; Cui, Z. Q.; Xie, X. F.; Ge, L. J.; Yuan, X.; Li, X. Q.; Zhang, G. H.; Chen, J. X.; Fan, T. S.; Gorini, G.; Nocente, M.; Tardocchi, M.; Hu, L. Q.; Zhong, G. Q.; Lin, S. Y.; Wan, B. N.

    2014-11-15

    The 2.5 MeV neutron spectrometer TOFED (Time-Of-Flight Enhanced Diagnostics) has been constructed to perform advanced neutron emission spectroscopy diagnosis of deuterium plasmas on EAST. The instrument has a double-ring structure which, in combination with pulse shape digitization, allows for a dual kinematic selection in the time-of-flight/recoil proton energy (tof/E{sub p}) space, thus improving the spectrometer capability to resolve fast ion signatures in the neutron spectrum, in principle up to a factor ≈100. The identification and separation of features from the energetic ions in the neutron spectrum depends on the detailed knowledge of the instrument response function, both in terms of the light output function of the scintillators and the effect of undesired multiple neutron scatterings in the instrument. This work presents the determination of the light output function of the TOFED plastic scintillator detectors and their geometrical assembly. Results from dedicated experiments with γ-ray sources and quasi-monoenergetic neutron beams are presented. Implications on the instrument capability to perform background suppression based on double kinematic selection are discussed.

  18. Light output function and assembly of the time-of-flight enhanced diagnostics neutron spectrometer plastic scintillators for background reduction by double kinematic selection at EAST.

    PubMed

    Peng, X Y; Chen, Z J; Zhang, X; Hu, Z M; Du, T F; Cui, Z Q; Xie, X F; Ge, L J; Yuan, X; Gorini, G; Nocente, M; Tardocchi, M; Hu, L Q; Zhong, G Q; Lin, S Y; Wan, B N; Li, X Q; Zhang, G H; Chen, J X; Fan, T S

    2014-11-01

    The 2.5 MeV neutron spectrometer TOFED (Time-Of-Flight Enhanced Diagnostics) has been constructed to perform advanced neutron emission spectroscopy diagnosis of deuterium plasmas on EAST. The instrument has a double-ring structure which, in combination with pulse shape digitization, allows for a dual kinematic selection in the time-of-flight/recoil proton energy (tof/Ep) space, thus improving the spectrometer capability to resolve fast ion signatures in the neutron spectrum, in principle up to a factor ≈100. The identification and separation of features from the energetic ions in the neutron spectrum depends on the detailed knowledge of the instrument response function, both in terms of the light output function of the scintillators and the effect of undesired multiple neutron scatterings in the instrument. This work presents the determination of the light output function of the TOFED plastic scintillator detectors and their geometrical assembly. Results from dedicated experiments with γ-ray sources and quasi-monoenergetic neutron beams are presented. Implications on the instrument capability to perform background suppression based on double kinematic selection are discussed. PMID:25430291

  19. Light scattering in paper measured with a time-of-flight lidar

    NASA Astrophysics Data System (ADS)

    Saarela, Juha; Myllyla, Risto A.

    2003-08-01

    This paper studies the correlation between the time-of-flight (TOF) of laser pulses and paper density, basis weight, thickness and the beating of pulp. Paper samples made from unbeaten and beaten pulp were compressed from 500kg/m3 to 1100kg/m3 and laser pulses were shot through them during pressing. Changes were observed in the thickness of the samples and in the TOF of the laser pulses. The results show that TOF decreases during comrpession. This indicates that distances between the various scattering surfaces decrease. This phenomenon becomes more pronounced as the basis weight increases. The beating of the pulp before papermaking increases the number of scattering surfaces, thus broadening the laser pulse and causing delay. These two effects cannot be separated with the equipment used. Papers made from different pulp types each have unique delay constants.

  20. Delayed bunching for multi-reflection time-of-flight mass separation

    NASA Astrophysics Data System (ADS)

    Rosenbusch, M.; Chauveau, P.; Delahaye, P.; Marx, G.; Schweikhard, L.; Wienholtz, F.; Wolf, R. N.

    2015-06-01

    Many experiments are handicapped when the ion sources do not only deliver the ions of interest but also contaminations, i.e., unwanted ions of similar mass. In the recent years, multi-reflection time-of-flight mass separation has become a promising method to isolate the ions of interest from the contaminants, in particular for measurements with low-energy short-lived nuclides. To further improve the performance of multi-reflection mass separators with respect to the limitations by space-charge effects, the simultaneously trapped ions are spatially widely distributed in the apparatus. Thus, the ions can propagate with reduced Coulomb interactions until, finally, they are bunched by a change in the trapping conditions for high-resolution mass separation. Proof-of-principle measurements are presented.

  1. Improved time-of-flight range acquisition technique in underwater lidar experiments.

    PubMed

    Cheng, Zao; Yang, Kecheng; Han, Jiefei; Zhou, Yiyu; Sun, Liying; Li, Wei; Xia, Min

    2015-06-20

    This paper presents an underwater lidar time-of-flight ranging system that combines the variable forgivable factor recursive least-squares (VFF-RLS) adaptive filter algorithm and the constant fraction discriminator (CFD) timing technology. The effectiveness of suppressing the backscattering and increasing timing accuracy is experimentally verified in the water basin under the different target distances, especially near the detection limit. The classical RLS is creatively transformed by introducing the VFF, which is highly correlated to the target echo at any distance. The improvement of the signal-to-backscatter ratio always exceeds 18.9 dB. The Monte Carlo simulation proves the applicability of the proposed method in the media of different turbidity. The influences of the selective timing methods on the walk error and time jitter are compared, and the optimum zero point of CFD is achieved by the slope analysis of leading (falling) edge in experimental target pulses. PMID:26193020

  2. Quantum fluctuations and condensate fraction during time-of-flight expansion

    SciTech Connect

    Fang Shiang; Lee, Ray-Kuang; Wang, Daw-Wei

    2010-09-15

    The quantum fluctuation effects in the time-of-flight (TOF) experiment for a condensate released from an optical-lattice potential is studied within the truncated Wigner approximation. By investigating both the spatial and momentum density distributions, we find that the condensate fraction decreases monotonically in time and hence cannot be measured in the standard TOF image. We then propose a semiquantitative analysis for such dynamical quantum-depletion process. Our study shows a universal algebraic decay of the true condensate fraction, and has a very good agreement with numerical results. We also discuss possible methods to determine the condensate fraction inside the optical lattice, and its implication to the TOF experiments in higher dimensional systems.

  3. Spin excitations in cubic maghemite nanoparticles studied by time-of-flight neutron spectroscopy

    NASA Astrophysics Data System (ADS)

    Disch, S.; Hermann, R. P.; Wetterskog, E.; Podlesnyak, A. A.; An, K.; Hyeon, T.; Salazar-Alvarez, G.; Bergström, L.; Brückel, Th.

    2014-02-01

    We have determined the field dependence of collective magnetic excitations in iron oxide nanoparticles of cubic shape with 8.42(2) nm edge length and a narrow log normal size distribution of 8.2(2)% using time-of-flight neutron spectroscopy. The energy dependence of the uniform precession modes was investigated up to 5 T applied field and yields a Landé factor g =2.05(2) as expected for maghemite (γ-Fe2O3) nanoparticles. A large effective anisotropy field of BA ,eff=0.45(16) T was determined, in excellent agreement with macroscopic measurements. This anisotropy is attributed to enhanced shape anisotropy in these monodisperse cubic nanoparticles. The combination of our results with macroscopic magnetization information provides a consistent view of the energy scales of superparamagnetic relaxation and collective magnetic excitations in magnetic nanoparticles.

  4. Phase-aware candidate selection for time-of-flight depth map denoising

    NASA Astrophysics Data System (ADS)

    Hach, Thomas; Seybold, Tamara; Böttcher, Hendrik

    2015-03-01

    This paper presents a new pre-processing algorithm for Time-of-Flight (TOF) depth map denoising. Typically, denoising algorithms use the raw depth map as it comes from the sensor. Systematic artifacts due to the measurement principle are not taken into account which degrades the denoising results. For phase measurement TOF sensing, a major artifact is observed as salt-and-pepper noise caused by the measurement's ambiguity. Our pre-processing algorithm is able to isolate and unwrap affected pixels deploying the physical behavior of the capturing system yielding Gaussian noise. Using this pre-processing method before applying the denoising step clearly improves the parameter estimation for the denoising filter together with its final results.

  5. Campaign 1.7 Pu Aging. Development of Time of Flight Secondary Ion Mass Spectroscopy

    SciTech Connect

    Venhaus, Thomas J.

    2015-09-09

    The first application of Time-of-Flight Secondary Ion Mass Spectroscopy (ToF-SIMS) to an aged plutonium surface has resulted in a rich set of surface chemistry data, as well as some unexpected results. FY15 was highlighted by not only the first mapping of hydrogen-containing features within the metal, but also a prove-in series of experiments using the system’s Sieverts Reaction Cell. These experiments involved successfully heating the sample to ~450 oC for nearly 24 hours while the sample was dosed several times with hydrogen, followed by an in situ ToF-SIMS analysis. During this year, the data allowed for better and more consistent identification of the myriad peaks that result from the SIMS sputter process. In collaboration with the AWE (U.K), the system was also fully aligned for sputter depth profiling for future experiments.

  6. Delayed bunching for multi-reflection time-of-flight mass separation

    SciTech Connect

    Rosenbusch, M.; Marx, G.; Schweikhard, L.; Wienholtz, F.; Chauveau, P.; Delahaye, P.

    2015-06-29

    Many experiments are handicapped when the ion sources do not only deliver the ions of interest but also contaminations, i.e., unwanted ions of similar mass. In the recent years, multi-reflection time-of-flight mass separation has become a promising method to isolate the ions of interest from the contaminants, in particular for measurements with low-energy short-lived nuclides. To further improve the performance of multi-reflection mass separators with respect to the limitations by space-charge effects, the simultaneously trapped ions are spatially widely distributed in the apparatus. Thus, the ions can propagate with reduced Coulomb interactions until, finally, they are bunched by a change in the trapping conditions for high-resolution mass separation. Proof-of-principle measurements are presented.

  7. Quantitative analysis of biomolecules by time-of-flight secondary-ion mass spectrometry: Fundamental considerations

    SciTech Connect

    Muddiman, D.C.; Nicola, A.J.; Proctor, A.

    1995-12-31

    Static Time-of-Flight Secondary-Ion Mass Spectrometry (TOF-SIMS) has been applied to investigate an extensive assortment of analytical systems; from semiconductors to DNA sequencing. Recently, the TOF-SIMS method has been successfully applied to real biological systems. This report focuses on some important aspects that must be taken into consideration when conducting measurements on biomaterials in order to observe the potential the TOF-SIMS method affords. The current data are presented using Cyclosporin A (CsA, 1202 Da) and cocaine (303 Da) as model compounds. CsA is observed in the TOF-SIMS mass spectrum predominately as a Ag-cationized species and cocaine as a protonated species; thus, they are complementary probe molecules.

  8. Stopping power measurements with the Time-of-Flight (ToF) technique

    SciTech Connect

    Fontana, Cristiano L.; Chen, Chien-Hung; Crespillo, Miguel L.; Graham, Joseph T.; Xue, Haizhou; Zhang, Yanwen; Weber, William J.

    2015-11-10

    In our review of measurements of the stopping power of ions in matter is presented along with new measurements of the stopping powers of O, Si, Ti, and Au ions in self-supporting thin foils of SiO2, Nb2O5, and Ta2O5. Moreover, a Time-of-Flight system at the Ion Beam Materials Laboratory at the University of Tennessee, Knoxville, was used in transmission geometry in order to reduce experimental uncertainties. Finally, the resulting stopping powers show good precision and accuracy and corroborate previously quoted values in the literature. New stopping data are determined.

  9. Objective Error Criterion for Evaluation of Mapping Accuracy Based on Sensor Time-of-Flight Measurements

    PubMed Central

    Barshan, Billur

    2008-01-01

    An objective error criterion is proposed for evaluating the accuracy of maps of unknown environments acquired by making range measurements with different sensing modalities and processing them with different techniques. The criterion can also be used for the assessment of goodness of fit of curves or shapes fitted to map points. A demonstrative example from ultrasonic mapping is given based on experimentally acquired time-of-flight measurements and compared with a very accurate laser map, considered as absolute reference. The results of the proposed criterion are compared with the Hausdorff metric and the median error criterion results. The error criterion is sufficiently general and flexible that it can be applied to discrete point maps acquired with other mapping techniques and sensing modalities as well.

  10. Depth profiling and imaging capabilities of an ultrashort pulse laser ablation time of flight mass spectrometer

    PubMed Central

    Cui, Yang; Moore, Jerry F.; Milasinovic, Slobodan; Liu, Yaoming; Gordon, Robert J.; Hanley, Luke

    2012-01-01

    An ultrafast laser ablation time-of-flight mass spectrometer (AToF-MS) and associated data acquisition software that permits imaging at micron-scale resolution and sub-micron-scale depth profiling are described. The ion funnel-based source of this instrument can be operated at pressures ranging from 10−8 to ∼0.3 mbar. Mass spectra may be collected and stored at a rate of 1 kHz by the data acquisition system, allowing the instrument to be coupled with standard commercial Ti:sapphire lasers. The capabilities of the AToF-MS instrument are demonstrated on metal foils and semiconductor wafers using a Ti:sapphire laser emitting 800 nm, ∼75 fs pulses at 1 kHz. Results show that elemental quantification and depth profiling are feasible with this instrument. PMID:23020378

  11. Time-of-flight detection of monoatomic ions generated by femtosecond laser ablation from large molecules

    NASA Astrophysics Data System (ADS)

    Kato, Toshiyuki; Kobayashi, Tohru; Kurata-Nishimura, Mizuki; Okamura-Oho, Yuko; Sano, Takuma; Oyama, Rieko; Matsumura, Yonehiro; Yamamoto, Hiroshi; Hayashizaki, Yoshihide; Matsuo, Yukari; Kawai, Jun

    2008-03-01

    Single-shot femtosecond laser ablation (fsLA) was applied to large molecules to analyze elemental composition through out wide range of mass-to-charge ratio. Molecular samples such as Eu-DNA and cosmetic powders were atomized and ionized simultaneously by the single-shot fsLA and positive atomic ions were detected using a reflectron time-of-flight (TOF) mass spectrometer. The ratios among the signal intensity of the detected stable isotopes including 151,153Eu and 182-184,186W were consistent with the respective natural abundances of the isotopes. The results demonstrate the feasibility of the fsLA-TOF method as a high-throughput analytical technique for elemental microanalysis of large molecular samples in small quantities.

  12. Encrypted Three-dimensional Dynamic Imaging using Snapshot Time-of-flight Compressed Ultrafast Photography.

    PubMed

    Liang, Jinyang; Gao, Liang; Hai, Pengfei; Li, Chiye; Wang, Lihong V

    2015-01-01

    Compressed ultrafast photography (CUP), a computational imaging technique, is synchronized with short-pulsed laser illumination to enable dynamic three-dimensional (3D) imaging. By leveraging the time-of-flight (ToF) information of pulsed light backscattered by the object, ToF-CUP can reconstruct a volumetric image from a single camera snapshot. In addition, the approach unites the encryption of depth data with the compressed acquisition of 3D data in a single snapshot measurement, thereby allowing efficient and secure data storage and transmission. We demonstrated high-speed 3D videography of moving objects at up to 75 volumes per second. The ToF-CUP camera was applied to track the 3D position of a live comet goldfish. We have also imaged a moving object obscured by a scattering medium. PMID:26503834

  13. Data acquisition system with pulse height capability for the TOFED time-of-flight neutron spectrometer

    SciTech Connect

    Chen, Z. J.; Peng, X. Y.; Zhang, X.; Du, T. F.; Hu, Z. M.; Cui, Z. Q.; Ge, L. J.; Xie, X. F.; Yuan, X.; Li, X. Q.; Zhang, G. H.; Chen, J. X.; Fan, T. S.; Gorini, G.; Nocente, M.; Tardocchi, M.; Hu, L. Q.; Zhong, G. Q.; Lin, S. Y.; Wan, B. N.

    2014-11-15

    A new time-of-flight neutron spectrometer TOFED has been constructed for installation at Experimental Advanced Superconducting Tokamak. A data acquisition system combining measurements of flight time and energy from the interaction of neutrons with the TOFED scintillators has been developed. The data acquisition system can provide a digitizing resolution better than 1.5% (to be compared with the >10% resolution of the recoil particle energy in the plastic scintillators) and a time resolution <1 ns. At the same time, it is compatible with high count rate event recording, which is an essential feature to investigate phenomena occurring on time scales faster than the slowing down time (≈100 ms) of the beam ions in the plasma. Implications of these results on the TOFED capability to resolve fast ion signatures in the neutron spectrum from EAST plasmas are discussed.

  14. Time of flight spectrometer for background-free positron annihilation induced Auger electron spectroscopy.

    PubMed

    Mukherjee, S; Shastry, K; Anto, C V; Joglekar, P V; Nadesalingam, M P; Xie, S; Jiang, N; Weiss, A H

    2016-03-01

    We describe a novel spectrometer designed for positron annihilation induced Auger electron spectroscopy employing a time-of-flight spectrometer. The spectrometer's new configuration enables us to implant monoenergetic positrons with kinetic energies as low as 1.5 eV on the sample while simultaneously allowing for the detection of electrons emitted from the sample surface at kinetic energies ranging from ∼500 eV to 0 eV. The spectrometer's unique characteristics made it possible to perform (a) first experiments demonstrating the direct transition of a positron from an unbound scattering state to a bound surface state and (b) the first experiments demonstrating that Auger electron spectra can be obtained down to 0 eV without the beam induced secondary electron background obscuring the low energy part of the spectra. Data are presented which show alternative means of estimating positron surface state binding energy and background-free Auger spectra. PMID:27036826

  15. A large-area time-of-flight system for a colliding beam machine

    NASA Astrophysics Data System (ADS)

    Basile, M.; Cara Romeo, G.; Cifarelli, L.; D'Ali, G.; Di Cesare, P.; Giusti, P.; Massam, T.; Palmonari, F.; Sartorelli, G.; Valenti, G.; Contin, A.; Favale, L.; Zichichi, A.; Esposito, B.

    1981-02-01

    We describe the performance of a large solid-angle (2 sr) time-of-flight system used in conjunction with the Split Field Magnet spectrometer of the CERN Intersecting Storage Rings (ISR). The system consists of a hodoscope of 67 scintillator counters, at a distance of about 5 m from the beam intersection. The ISR being a coasting beam machine, contrary to the tightly bunched e +e - machines, the event time is unknown and therefore a special analysis procedure for particle identification is required. We illustrate a powerful statistical method which allows the identification, with more than 90% efficiency, of pions up to about 1 GeV/c, kaons up to about 1.4 GeV/c, and protons up to about 2 GeV/c.

  16. Automated Gain Control Ion Funnel Trap for Orthogonal Time-of-Flight Mass Spectrometry

    PubMed Central

    Ibrahim, Yehia M.; Belov, Mikhail E.; Liyu, Andrei V.; Smith, Richard D.

    2009-01-01

    Time-of-flight mass spectrometry (TOF MS) is increasingly used in proteomics research. Herein, we report on the development and characterization of a TOF MS instrument with improved sensitivity equipped with an electrodynamic ion funnel trap (IFT) that employs an automated gain control (AGC) capability. The IFT-TOF MS was coupled to a reversed-phase capillary liquid chromatography (RPLC) separation and evaluated in experiments with complex proteolytic digests. When applied to a global tryptic digest of Shewanella oneidensis proteins, an order-of-magnitude increase in sensitivity compared to that of the conventional continuous mode of operation was achieved due to efficient ion accumulation prior to TOF MS analysis. As a result of this sensitivity improvement and related improvement in mass measurement accuracy, the number of unique peptides identified in the AGC-IFT mode was 5-fold greater than that obtained in the continuous mode. PMID:18512944

  17. Depth Imaging by Combining Time-of-Flight and On-Demand Stereo

    NASA Astrophysics Data System (ADS)

    Hahne, Uwe; Alexa, Marc

    In this paper we present a framework for computing depth images at interactive rates. Our approach is based on combining time-of-flight (TOF) range data with stereo vision. We use a per-frame confidence map extracted from the TOF sensor data in two ways for improving the disparity estimation in the stereo part: first, together with the TOF range data for initializing and constraining the disparity range; and, second, together with the color image information for segmenting the data into depth continuous areas, enabling the use of adaptive windows for the disparity search. The resulting depth images are more accurate than from either of the sensors. In an example application we use the depth map to initialize the z-buffer so that virtual objects can be occluded by real objects in an augmented reality scenario.

  18. Time-of-flight mobility and trapping results for ZnSe.

    NASA Technical Reports Server (NTRS)

    Heaton, J. L., III; Hammond, G. H.; Goldner, R. B.

    1972-01-01

    Results of measurements of time-of-flight mobility and trapping for zinc selenide. The data were obtained at room temperature for electric fields in the range from 30,000 to 800,000 V/cm. A relatively constant hole mobility (about 50 sq cm/V sec) was found for the entire range of investigated fields. The electron mobility was approximately constant (about 400 sq cm/V sec) up to approximately equal to 300,000 V/cm, above which the drift velocity remained constant. No obvious negative differential mobility was observed, even though the Gunn effect has been reported for the field range investigated. Trapping and detrapping times in the vicinity of 1 nsec are reported for both holes and electrons. The field dependence of the electron-trapping times is unusual and remains unexplained.

  19. Multiphoton Ionization Time-of-Flight Mass Spectrometry for the Detection of Bioactive Lignan.

    PubMed

    Uchimura, Tomohiro; Tokumoto, Goro; Batnyam, Onon; Chou, Chih-Wei; Fujita, Satoshi

    2016-01-01

    Multiphoton ionization time-of-flight mass spectrometry (MPI-TOFMS) combined with a pulsed laser for sample vaporization was developed for the detection of a low-volatile compound in a solution. A solution containing Taiwanin A ((3E,4E)-3,4-bis(1,3-benzodioxol-5-ylmethylene)dihydro-2(3H)-furanone), which is a lignan that has an anticancer effect, was employed in the present study. Consequently, Taiwanin A could be detected by irradiating a laser pulse for vaporization to an inlet nozzle, rather than by heating. Therefore, the present method could be effective for detecting compounds with lower volatilities in a liquid sample. PMID:26860576

  20. The new time-of-flight ERDA setup at the HMI-Berlin

    NASA Astrophysics Data System (ADS)

    Bohne, W.; Röhrich, J.; Röschert, G.

    1998-04-01

    The new time-of-flight ERDA (TOF ERDA) spectrometer of the Hahn-Meitner-Institut Berlin is presented. It is located at a high-energy target position of the ion-beam laboratory (ISL). The great variety of ions from helium to xenon with variable energies up to several MeV/amu allows the determination of the distribution of all elements in the samples up to a depth of some micrometer. The measurement of the hydrogen concentration is possible with high efficiency. With the relatively large solid angle of 1.57 msr fast measurements with low ion beam currents are possible. The long flight path of 123 cm and a time resolution of about 180 ps enable a good mass and depth resolution.

  1. Modeling of microsystem flow sensor based on thermal time-of-flight mode

    NASA Astrophysics Data System (ADS)

    Hariadi, Ihsan; Trieu, Hoc-Khiem; Vogt, Holger

    2002-04-01

    This paper reports the results of the modeling silicon microsystem flow sensor based on Thermal Time-Of-Flight (TTOF) mode. The basic heat transfer equations and the modeling approach are first presented. The problem domain is decomposed into two subdomains which represent the fluid and the sensor chip structure, respectively. The thermal boundary layer where the interaction between the two subdomains is taking place is modeled using flow-dependent equivalent thermal resistance elements. The two subdomains and the boundary layer are subsequently implemented using the combination of SPICE and analog HDL. An experimental chip of silicon thermal flow sensor is used to validate the present model. The model has been used to predict the behavior of the flow sensor in free-running TTOF mode and also in Thermal-Convection Delay-Line Oscillator (TC-DLO) mode. Both the agreement and discrepancy found between the model and the experiments are shown and discussed.

  2. High precision electric gate for time-of-flight ion mass spectrometers

    NASA Technical Reports Server (NTRS)

    Sittler, Edward C. (Inventor)

    2011-01-01

    A time-of-flight mass spectrometer having a chamber with electrodes to generate an electric field in the chamber and electric gating for allowing ions with a predetermined mass and velocity into the electric field. The design uses a row of very thin parallel aligned wires that are pulsed in sequence so the ion can pass through the gap of two parallel plates, which are biased to prevent passage of the ion. This design by itself can provide a high mass resolution capability and a very precise start pulse for an ion mass spectrometer. Furthermore, the ion will only pass through the chamber if it is within a wire diameter of the first wire when it is pulsed and has the right speed so it is near all other wires when they are pulsed.

  3. Time-of-flight diffraction at pulsed neutron sources: An introduction to the symposium

    SciTech Connect

    Jorgensen, J.D.

    1994-05-01

    In the 25 years since the first low-power demonstration experiments, pulsed neutron sources have become as productive as reactor sources for many types of diffraction experiments. The pulsed neutron sources presently operating in the United States, England, and Japan offer state of the art instruments for powder and single crystal diffraction, small angle scattering, and such specialized techniques as grazing-incidence neutron reflection, as well as quasielastic and inelastic scattering. In this symposium, speakers review the latest advances in diffraction instrumentation for pulsed neutron sources and give examples of some of the important science presently being done. In this introduction to the symposium, I briefly define the basic principles of pulsed neutron sources, review their development, comment in general terms on the development of time-of-flight diffraction instrumentation for these sources, and project how this field will develop in the next ten years.

  4. Spatial investigations of ion and electron time of flight in laser ablated ZnO plasma

    NASA Astrophysics Data System (ADS)

    Joshy, N. V.; Jayaraj, M. K.

    2010-02-01

    The time of flight (TOF) spectra of ions and electrons of laser ablated ZnO:Ga plasma plume were recorded. The laser fluence was varied from 2.55 Jcm-2 to 17.85 Jcm-2 and the ablation was carried out in vacuum and N2O ambient pressure ranging from 0.0001 mbar to 0.1 mbar. The TOF spectra were recorded at positions 10 mm to 50 mm from the target surface along the direction normal to the surface. Ion acceleration and corresponding electron deceleration were detected in the plasma due to the formation of electric double layer during plasma expansion. Twin peaks were recorded in the ion TOF spectra-corresponding to accelerated and thermal ions, while two categories of thermal electrons were detected in electron TOF spectra. The behaviour of these ions and electrons is studied as a function of laser fluence, ambient gas pressure and distance from the target surface.

  5. Porosity detection in ceramic armor tiles via ultrasonic time-of-flight

    SciTech Connect

    Margetan, Frank J.; Richter, Nathaniel; Jensen, Terrence

    2011-06-23

    Some multilayer armor panels contain ceramic tiles as one constituent, and porosity in the tiles can affect armor performance. It is well known that porosity in ceramic materials leads to a decrease in ultrasonic velocity. We report on a feasibility study exploring the use of ultrasonic time-of-flight (TOF) to locate and characterize porous regions in armor tiles. The tiles in question typically have well-controlled thickness, thus simplifying the translation of TOF data into velocity data. By combining UT velocity measurements and X-ray absorption measurements on selected specimens, one can construct a calibration curve relating velocity to porosity. That relationship can then be used to translate typical ultrasonic C-scans of TOF-versus-position into C-scans of porosity-versus-position. This procedure is demonstrated for pulse/echo, focused-transducer inspections of silicon carbide (SiC) ceramic tiles.

  6. Laser Time-of-Flight Mass Spectrometry for Future In Situ Planetary Missions

    NASA Technical Reports Server (NTRS)

    Getty, S. A.; Brinckerhoff, W. B.; Cornish, T.; Ecelberger, S. A.; Li, X.; Floyd, M. A. Merrill; Chanover, N.; Uckert, K.; Voelz, D.; Xiao, X.; Tawalbeh, R.; Glenar, D.; Elsila, J. E.; Callahan, M.

    2012-01-01

    Laser desorption/ionization time-of-flight mass spectrometry (LD-TOF-MS) is a versatile, low-complexity instrument class that holds significant promise for future landed in situ planetary missions that emphasize compositional analysis of surface materials. Here we describe a 5kg-class instrument that is capable of detecting and analyzing a variety of analytes directly from rock or ice samples. Through laboratory studies of a suite of representative samples, we show that detection and analysis of key mineral composition, small organics, and particularly, higher molecular weight organics are well suited to this instrument design. A mass range exceeding 100,000 Da has recently been demonstrated. We describe recent efforts in instrument prototype development and future directions that will enhance our analytical capabilities targeting organic mixtures on primitive and icy bodies. We present results on a series of standards, simulated mixtures, and meteoritic samples.

  7. A quadrupole/time-of-flight mass spectrometry study of Trp-cage's conformation.

    PubMed

    Lin, Mingxiang; Ahmed, Zeeshan; Taormina, Christopher R; Somayajula, Kasi V

    2007-02-01

    Trp-cage is a synthetic 20-residue miniprotein that uses tertiary contacts to stabilize its native conformation. NMR, circular dichroism (CD), and UV-resonance Raman spectroscopy were used to probe its energy landscape. In this quadrupole/time-of-flight study, electrospray ionization charge state distribution (CSD) and solution-phase H/D exchange are used to probe Trp-cage's tertiary structure. The CSDs of Trp-cage and its mutant provide spectra showing a pH-dependent conformation change. Solution-phase H/D exchange in 30% deuterated trifluoroethanol solution of the wild type shows increased protection of one labile hydrogen in the native state. Together, CSDs and solution-phase H/D exchange are demonstrated to constitute a simple but effective means to follow conformation changes in a small tertiary protein. PMID:17067814

  8. Time of flight spectrometer for background-free positron annihilation induced Auger electron spectroscopy

    NASA Astrophysics Data System (ADS)

    Mukherjee, S.; Shastry, K.; Anto, C. V.; Joglekar, P. V.; Nadesalingam, M. P.; Xie, S.; Jiang, N.; Weiss, A. H.

    2016-03-01

    We describe a novel spectrometer designed for positron annihilation induced Auger electron spectroscopy employing a time-of-flight spectrometer. The spectrometer's new configuration enables us to implant monoenergetic positrons with kinetic energies as low as 1.5 eV on the sample while simultaneously allowing for the detection of electrons emitted from the sample surface at kinetic energies ranging from ˜500 eV to 0 eV. The spectrometer's unique characteristics made it possible to perform (a) first experiments demonstrating the direct transition of a positron from an unbound scattering state to a bound surface state and (b) the first experiments demonstrating that Auger electron spectra can be obtained down to 0 eV without the beam induced secondary electron background obscuring the low energy part of the spectra. Data are presented which show alternative means of estimating positron surface state binding energy and background-free Auger spectra.

  9. Encrypted Three-dimensional Dynamic Imaging using Snapshot Time-of-flight Compressed Ultrafast Photography

    NASA Astrophysics Data System (ADS)

    Liang, Jinyang; Gao, Liang; Hai, Pengfei; Li, Chiye; Wang, Lihong V.

    2015-10-01

    Compressed ultrafast photography (CUP), a computational imaging technique, is synchronized with short-pulsed laser illumination to enable dynamic three-dimensional (3D) imaging. By leveraging the time-of-flight (ToF) information of pulsed light backscattered by the object, ToF-CUP can reconstruct a volumetric image from a single camera snapshot. In addition, the approach unites the encryption of depth data with the compressed acquisition of 3D data in a single snapshot measurement, thereby allowing efficient and secure data storage and transmission. We demonstrated high-speed 3D videography of moving objects at up to 75 volumes per second. The ToF-CUP camera was applied to track the 3D position of a live comet goldfish. We have also imaged a moving object obscured by a scattering medium.

  10. Time-of-flight electron spectrometer for a broad range of kinetic energies.

    PubMed

    Kothe, Alexander; Metje, Jan; Wilke, Martin; Moguilevski, Alexandre; Engel, Nicholas; Al-Obaidi, Ruba; Richter, Clemens; Golnak, Ronny; Kiyan, Igor Yu; Aziz, Emad F

    2013-02-01

    A newly constructed time-of-flight electron spectrometer of the magnetic bottle type is characterized for electron detection in a broad range of kinetic energies. The instrument is designed to measure the energy spectra of electrons generated from liquids excited by strong laser fields and photons in the range of extreme ultra violet and soft X-rays. Argon inner shell electrons were recorded to calibrate the spectrometer and investigate its characteristics, such as energy resolution and collection efficiency. Its energy resolution ΔE/E of 1.6% allows resolving the Ar 2p spin orbit structure at kinetic energies higher than 100 eV. The collection efficiency is determined and compared to that of the spectrometer in its field-free configuration. PMID:23464194

  11. Time-of-flight electron spectrometer for a broad range of kinetic energies

    NASA Astrophysics Data System (ADS)

    Kothe, Alexander; Metje, Jan; Wilke, Martin; Moguilevski, Alexandre; Engel, Nicholas; Al-Obaidi, Ruba; Richter, Clemens; Golnak, Ronny; Kiyan, Igor Yu.; Aziz, Emad F.

    2013-02-01

    A newly constructed time-of-flight electron spectrometer of the magnetic bottle type is characterized for electron detection in a broad range of kinetic energies. The instrument is designed to measure the energy spectra of electrons generated from liquids excited by strong laser fields and photons in the range of extreme ultra violet and soft X-rays. Argon inner shell electrons were recorded to calibrate the spectrometer and investigate its characteristics, such as energy resolution and collection efficiency. Its energy resolution ΔE/E of 1.6% allows resolving the Ar 2p spin orbit structure at kinetic energies higher than 100 eV. The collection efficiency is determined and compared to that of the spectrometer in its field-free configuration.

  12. Invited Article: Polarization ``Down Under'': The polarized time-of-flight neutron reflectometer PLATYPUS

    NASA Astrophysics Data System (ADS)

    Saerbeck, T.; Klose, F.; Le Brun, A. P.; Füzi, J.; Brule, A.; Nelson, A.; Holt, S. A.; James, M.

    2012-08-01

    This review presents the implementation and full characterization of the polarization equipment of the time-of-flight neutron reflectometer PLATYPUS at the Australian Nuclear Science and Technology Organisation (ANSTO). The functionality and efficiency of individual components are evaluated and found to maintain a high neutron beam polarization with a maximum of 99.3% through polarizing Fe/Si supermirrors. Neutron spin-flippers with efficiencies of 99.7% give full control over the incident and scattered neutron spin direction over the whole wavelength spectrum available in the instrument. The first scientific experiments illustrate data correction mechanisms for finite polarizations and reveal an extraordinarily high reproducibility for measuring magnetic thin film samples. The setup is now fully commissioned and available for users through the neutron beam proposal system of the Bragg Institute at ANSTO.

  13. Joint Temperature-Lasing Mode Compensation for Time-of-Flight LiDAR Sensors

    PubMed Central

    Alhashimi, Anas; Varagnolo, Damiano; Gustafsson, Thomas

    2015-01-01

    We propose an expectation maximization (EM) strategy for improving the precision of time of flight (ToF) light detection and ranging (LiDAR) scanners. The novel algorithm statistically accounts not only for the bias induced by temperature changes in the laser diode, but also for the multi-modality of the measurement noises that is induced by mode-hopping effects. Instrumental to the proposed EM algorithm, we also describe a general thermal dynamics model that can be learned either from just input-output data or from a combination of simple temperature experiments and information from the laser’s datasheet. We test the strategy on a SICK LMS 200 device and improve its average absolute error by a factor of three. PMID:26690445

  14. The distribution of "time of flight" in three dimensional stationary chaotic advection

    NASA Astrophysics Data System (ADS)

    Raynal, Florence; Carrière, Philippe

    2015-04-01

    The distributions of "time of flight" (time spent by a single fluid particle between two crossings of the Poincaré section) are investigated for five different three dimensional stationary chaotic mixers. Above all, we study the large tails of those distributions and show that mainly two types of behaviors are encountered. In the case of slipping walls, as expected, we obtain an exponential decay, which, however, does not scale with the Lyapunov exponent. Using a simple model, we suggest that this decay is related to the negative eigenvalues of the fixed points of the flow. When no-slip walls are considered, as predicted by the model, the behavior is radically different, with a very large tail following a power law with an exponent close to -3.

  15. Laser ranging by time-of-flight measurement of femtosecond light pulses

    NASA Astrophysics Data System (ADS)

    Kim, Young-Jin

    2014-04-01

    Time-of-flight (TOF) measurement of femtosecond light pulses was investigated for laser ranging of long distances with sub-micrometer precision in the air. The bandwidth limitation of the photo-detection electronics used in timing femtosecond pulses was overcome by adopting a type-II nonlinear second-harmonic crystal that permits producing the balanced optical cross-correlation signal between two overlapped light pulses. This method offered a sub-femtosecond timing resolution in determining the temporal offset between two pulses through lock-in control of the pulse repetition rate with reference to the atomic clock. The exceptional ranging capability was verified by measuring various distances from 1.5 m to 700 m. This method is found suited for terrestrial land surveying and space missions of formation-flying satellites.

  16. TOFwave: reproducibility in biomarker discovery from time-of-flight mass spectrometry data.

    PubMed

    Chierici, Marco; Albanese, Davide; Franceschi, Pietro; Furlanello, Cesare

    2012-11-01

    Many are the sources of variability that can affect reproducibility of disease biomarkers from time-of-flight (TOF) Mass Spectrometry (MS) data. Here we present TOFwave, a complete software pipeline for TOF-MS biomarker identification, that limits the impact of parameter tuning along the whole chain of preprocessing and model selection modules. Peak profiles are obtained by a preprocessing based on Continuous Wavelet Transform (CWT), coupled with a machine learning protocol aimed at avoiding selection bias effects. Only two parameters (minimum peak width and a signal to noise cutoff) have to be explicitly set. The TOFwave pipeline is built on top of the mlpy Python package. Examples on Matrix-Assisted Laser Desorption and Ionization (MALDI) TOF datasets are presented. Software prototype, datasets and details to replicate results in this paper can be found at http://mlpy.sf.net/tofwave/. PMID:22875362

  17. Matrix assisted laser desorption ionization-time of flight mass spectrometry analysis of hyaluronan oligosaccharides

    PubMed Central

    Sakai, Shinobu; Hirano, Kana; Toyoda, Hidenao; Linhardt, Robert J.; Toida, Toshihiko

    2014-01-01

    A new method is presented for the identification of oligosaccharides obtained by enzymatic digestion of hyaluronan (HA) with bacterial hyaluronidase (E.C. 4.2.2.1, from Streptomyces hyalurolyticus) using matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOFMS). Mixtures containing HA oligosaccharides of tetrasaccharide (4-mer)–34-mer were analyzed using this method. The carboxyl groups of the glucuronate residues in the prepared HA oligomers, were modified as the acidic form (—COOH), sodium salts (—COONa), organic ammonium salts, or methylesters before MALDI-TOFMS measurement. Among these samples, the methylester form of glucuronate residues in HA oligosaccharides, prepared by methylation using trimethylsilyl diazomethane, afforded high sensitivity for spectra. This simple modification method for carboxyl group methylation of acidic polysaccharides [Hirano et al., Carbohydr. Res., 340, (2005) 2297–2304] provides samples suitable for MALDI-TOF mass spectrometric analysis throughout a significantly enhanced range of masses. PMID:17543609

  18. Standardization of time-of-flight laser ionization mass spectrometry analysis of minerals

    NASA Astrophysics Data System (ADS)

    Dimov, S. S.; Chryssoulis, S. L.

    1998-03-01

    The standardization of the time-of-flight laser ionization mass spectrometry (TOF-LIMS) analysis of mineral surfaces is an important step towards providing reproducible quantitative data. This paper reports the search for experimental conditions and instrumental configurations that provide efficient ionization for all elements of the sample. For that purpose, an investigation of the neutral emission dynamics and the ion yields for the most important elements, as a function of laser power densities, the relative time delay between the ablation and postionization processes, and the sample matrix, was performed. In order to standardize the procedure, an empirical protocol was established, based on the use of optimized system parameters to monitor the ion yield from a library of standard reference samples.

  19. Electronics of an ion trap with integrated time-of-flight mass spectrometer

    NASA Astrophysics Data System (ADS)

    Schneider, Christian; Schowalter, Steven J.; Yu, Peter; Hudson, Eric R.

    2016-01-01

    Recently, we reported an ion trap experiment with an integrated time-of-flight mass spectrometer (TOFMS) [Phys. Rev. Appl. 2, 034013 (2014)] focussing on the improvement of mass resolution and detection limit due to sample preparation at millikelvin temperatures. The system utilizes a radio-frequency (RF) ion trap with asymmetric drive for storing and manipulating laser-cooled ions and features radial extraction into a compact $275$ mm long TOF drift tube. The mass resolution exceeds $m / \\Delta m = 500$, which provides isotopic resolution over the whole mass range of interest in current experiments and constitutes an improvement of almost an order of magnitude over other implementations. In this manuscript, we discuss the experimental implementation in detail, which is comprised of newly developed drive electronics for generating the required voltages to operate RF trap and TOFMS, as well as control electronics for regulating RF outputs and synchronizing the TOFMS extraction.

  20. Note: Ultrasonic gas flowmeter based on optimized time-of-flight algorithms

    NASA Astrophysics Data System (ADS)

    Wang, X. F.; Tang, Z. A.

    2011-04-01

    A new digital signal processor based single path ultrasonic gas flowmeter is designed, constructed, and experimentally tested. To achieve high accuracy measurements, an optimized ultrasound driven method of incorporation of the amplitude modulation and the phase modulation of the transmit-receive technique is used to stimulate the transmitter. Based on the regularities among the received envelope zero-crossings, different received signal's signal-to-noise ratio situations are discriminated and optional time-of-flight algorithms are applied to take flow rate calculations. Experimental results from the dry calibration indicate that the designed flowmeter prototype can meet the zero-flow verification test requirements of the American Gas Association Report No. 9. Furthermore, the results derived from the flow calibration prove that the proposed flowmeter prototype can measure flow rate accurately in the practical experiments, and the nominal accuracies after FWME adjustment are lower than 0.8% throughout the calibration range.

  1. Note: ultrasonic gas flowmeter based on optimized time-of-flight algorithms.

    PubMed

    Wang, X F; Tang, Z A

    2011-04-01

    A new digital signal processor based single path ultrasonic gas flowmeter is designed, constructed, and experimentally tested. To achieve high accuracy measurements, an optimized ultrasound driven method of incorporation of the amplitude modulation and the phase modulation of the transmit-receive technique is used to stimulate the transmitter. Based on the regularities among the received envelope zero-crossings, different received signal's signal-to-noise ratio situations are discriminated and optional time-of-flight algorithms are applied to take flow rate calculations. Experimental results from the dry calibration indicate that the designed flowmeter prototype can meet the zero-flow verification test requirements of the American Gas Association Report No. 9. Furthermore, the results derived from the flow calibration prove that the proposed flowmeter prototype can measure flow rate accurately in the practical experiments, and the nominal accuracies after FWME adjustment are lower than 0.8% throughout the calibration range. PMID:21529053

  2. Time-of-flight electron spectrometer for a broad range of kinetic energies

    SciTech Connect

    Kothe, Alexander; Metje, Jan; Wilke, Martin; Moguilevski, Alexandre; Engel, Nicholas; Al-Obaidi, Ruba; Richter, Clemens; Golnak, Ronny; Kiyan, Igor Yu.; Aziz, Emad F.

    2013-02-15

    A newly constructed time-of-flight electron spectrometer of the magnetic bottle type is characterized for electron detection in a broad range of kinetic energies. The instrument is designed to measure the energy spectra of electrons generated from liquids excited by strong laser fields and photons in the range of extreme ultra violet and soft X-rays. Argon inner shell electrons were recorded to calibrate the spectrometer and investigate its characteristics, such as energy resolution and collection efficiency. Its energy resolution {Delta}E/E of 1.6% allows resolving the Ar 2p spin orbit structure at kinetic energies higher than 100 eV. The collection efficiency is determined and compared to that of the spectrometer in its field-free configuration.

  3. Characterization of mustard seeds and paste by DART ionization with time-of-flight mass spectrometry.

    PubMed

    Prchalová, Jana; Kovařík, František; Ševčík, Rudolf; Čížková, Helena; Rajchl, Aleš

    2014-09-01

    Direct analysis in real time (DART) is a novel technique with great potential for rapid screening analysis. The DART ionization method coupled with high-resolution time-of-flight mass spectrometry (TOF-MS) has been used for characterization of mustard seeds and table mustard. The possibility to use DART to analyse glucosinolates was confirmed on determination of sinalbin (4-hydroxybenzyl glucosinolate). The DART-TOF-MS method was optimized and validated. A set of samples of mustard seeds and mustard products was analyzed. High-performance liquid chromatography and DART-TOF-MS were used to determine glucosinolates in mustard seeds and compared. The correlation equation between these methods was DART = 0.797*HPLC + 6.987, R(2)  = 0.972. The DART technique seems to be a suitable method for evaluation of the quality of mustard seeds and mustard products. PMID:25230177

  4. Encrypted Three-dimensional Dynamic Imaging using Snapshot Time-of-flight Compressed Ultrafast Photography

    PubMed Central

    Liang, Jinyang; Gao, Liang; Hai, Pengfei; Li, Chiye; Wang, Lihong V.

    2015-01-01

    Compressed ultrafast photography (CUP), a computational imaging technique, is synchronized with short-pulsed laser illumination to enable dynamic three-dimensional (3D) imaging. By leveraging the time-of-flight (ToF) information of pulsed light backscattered by the object, ToF-CUP can reconstruct a volumetric image from a single camera snapshot. In addition, the approach unites the encryption of depth data with the compressed acquisition of 3D data in a single snapshot measurement, thereby allowing efficient and secure data storage and transmission. We demonstrated high-speed 3D videography of moving objects at up to 75 volumes per second. The ToF-CUP camera was applied to track the 3D position of a live comet goldfish. We have also imaged a moving object obscured by a scattering medium. PMID:26503834

  5. A comparison of four direct geometry time-of-flight spectrometers at the Spallation Neutron Source

    SciTech Connect

    Stone, Matthew B; Niedziela, Jennifer L; Abernathy, Douglas L; Debeer-Schmitt, Lisa M; Garlea, Vasile O; Granroth, Garrett E; Graves-Brook, Melissa K; Ehlers, Georg; Kolesnikov, Alexander I; Podlesnyak, Andrey A; Winn, Barry L

    2014-04-01

    The Spallation Neutron Source at Oak Ridge National Laboratory now hosts four direct geometry time-of-flight chopper spectrometers. These instruments cover a range of wave vector and energy transfer space with varying degrees of neutron flux and resolution. The regions of reciprocal and energy space available to measure at these instruments is not exclusive and overlaps significantly. We present a direct comparison of the capabilities of this instrumentation, conducted by data mining the instrument usage histories, and specific scanning regimes. In addition, one of the common science missions for these instruments is the study of magnetic excitations in condensed matter systems. We have measured the powder averaged spin wave spectra in one particular sample using each of these instruments, and use these data in our comparisons.

  6. A comparison of four direct geometry time-of-flight spectrometers at the Spallation Neutron Source

    SciTech Connect

    Stone, M. B.; Abernathy, D. L.; Ehlers, G.; Garlea, O.; Podlesnyak, A.; Winn, B.; Niedziela, J. L.; DeBeer-Schmitt, L.; Graves-Brook, M.; Granroth, G. E.; Kolesnikov, A. I.

    2014-04-15

    The Spallation Neutron Source at Oak Ridge National Laboratory now hosts four direct geometry time-of-flight chopper spectrometers. These instruments cover a range of wave-vector and energy transfer space with varying degrees of neutron flux and resolution. The regions of reciprocal and energy space available to measure at these instruments are not exclusive and overlap significantly. We present a direct comparison of the capabilities of this instrumentation, conducted by data mining the instrument usage histories, and specific scanning regimes. In addition, one of the common science missions for these instruments is the study of magnetic excitations in condensed matter systems. We have measured the powder averaged spin wave spectra in one particular sample using each of these instruments, and use these data in our comparisons.

  7. A comparison of four direct geometry time-of-flight spectrometers at the Spallation Neutron Source.

    PubMed

    Stone, M B; Niedziela, J L; Abernathy, D L; DeBeer-Schmitt, L; Ehlers, G; Garlea, O; Granroth, G E; Graves-Brook, M; Kolesnikov, A I; Podlesnyak, A; Winn, B

    2014-04-01

    The Spallation Neutron Source at Oak Ridge National Laboratory now hosts four direct geometry time-of-flight chopper spectrometers. These instruments cover a range of wave-vector and energy transfer space with varying degrees of neutron flux and resolution. The regions of reciprocal and energy space available to measure at these instruments are not exclusive and overlap significantly. We present a direct comparison of the capabilities of this instrumentation, conducted by data mining the instrument usage histories, and specific scanning regimes. In addition, one of the common science missions for these instruments is the study of magnetic excitations in condensed matter systems. We have measured the powder averaged spin wave spectra in one particular sample using each of these instruments, and use these data in our comparisons. PMID:24784665

  8. A design for a high resolution very-low-Q time-of flight diffractometer.

    SciTech Connect

    Hjelm, R. P.

    1998-09-29

    The design of a high resolution view low-Q time of flight diffractometer was motivated by the anticipated need to perform small-angle neutron scattering measurements at far lower momentum transfer and higher precision than currently available at either pulsed or steady state sources. In addition, it was recognized that flexibility in the configuration of the instrument and ease in which data is acquired are important. The design offers two configurations, a high intensity/very low Q geometry employing a focusing mirror and a medium to high Q-precision/low Q configuration using standard pinhole collimation geometry. The quality of the mirror optics is very important to the performance of the high intensity/very low Q configuration. We believe that the necessary technology exists to fabricate the high quality mirror optics required for the instrument.

  9. Joint Temperature-Lasing Mode Compensation for Time-of-Flight LiDAR Sensors.

    PubMed

    Alhashimi, Anas; Varagnolo, Damiano; Gustafsson, Thomas

    2015-01-01

    We propose an expectation maximization (EM) strategy for improving the precision of time of flight (ToF) light detection and ranging (LiDAR) scanners. The novel algorithm statistically accounts not only for the bias induced by temperature changes in the laser diode, but also for the multi-modality of the measurement noises that is induced by mode-hopping effects. Instrumental to the proposed EM algorithm, we also describe a general thermal dynamics model that can be learned either from just input-output data or from a combination of simple temperature experiments and information from the laser's datasheet. We test the strategy on a SICK LMS 200 device and improve its average absolute error by a factor of three. PMID:26690445

  10. Development of picoseconds Time of Flight systems in Meson Test Beam Facility at Fermilab

    SciTech Connect

    Ronzhin, A.; Albrow, M.; Demarteau, M.; Los, S.; Malik, S.; Pronko, S.; Ramberg, E.; Zatserklyaniy, A.; /Puerto Rico U., Mayaguez

    2010-11-01

    The goal of the work is to develop time of flight (TOF) system with about 10 picosecond time resolution in real beam line when start and stop counters separated by some distance. We name the distance as 'base' for the TOF. This 'real' TOF setup is different from another one when start and stop counters located next to each other. The real TOF is sensitive to beam momentum spread, beam divergence, etc. Anyway some preliminary measurements are useful with close placement of start and stop counter. We name it 'close geometry'. The work started about 2 years ago at Fermilab Meson Test Beam Facility (MTBF). The devices tested in 'close geometry' were Microchannel Plate Photomultipliers (MCP PMT) with Cherenkov radiators. TOF counters based on Silicon Photomultipliers (SiPms) with Cherenkov radiators also in 'close geometry' were tested. We report here new results obtained with the counters in the MTBF at Fermilab, including beam line data.

  11. Atom-atom correlations in time-of-flight imaging of ultracold bosons in optical lattices

    SciTech Connect

    Zaleski, T. A.; Kopec, T. K.

    2011-11-15

    We study the spatial correlations of strongly interacting bosons in a ground state, confined in a two-dimensional square and a three-dimensional cubic lattice. Using the combined Bogoliubov method and the quantum rotor approach, we map the Hamiltonian of strongly interacting bosons onto U(1) phase action in order to calculate the atom-atom correlations' decay along the principal axis and a diagonal of the lattice-plane direction as a function of distance. Lower tunneling rates lead to quicker decays of the correlations, whose character becomes exponential. Finally, correlation functions allow us to calculate quantities that are directly bound to experimental outcomes, namely time-of-flight absorption images and resulting visibility. Our results contain all the characteristic features present in experimental data (transition from Mott insulating blob to superfluid peaks, etc.), emphasizing the usability of the proposed approach.

  12. Towards people detection from fused time-of-flight and thermal infrared images

    NASA Astrophysics Data System (ADS)

    Hoegner, L.; Hanel, A.; Weinmann, M.; Jutzi, B.; Hinz, S.; Stilla, U.

    2014-08-01

    Obtaining accurate 3d descriptions in the thermal infrared (TIR) is a quite challenging task due to the low geometric resolutions of TIR cameras and the low number of strong features in TIR images. Combining the radiometric information of the thermal infrared with 3d data from another sensor is able to overcome most of the limitations in the 3d geometric accuracy. In case of dynamic scenes with moving objects or a moving sensor system, a combination with RGB cameras of Time-of-Flight (TOF) cameras is suitable. As a TOF camera is an active sensor in the near infrared (NIR) and the thermal infrared camera captures the radiation emitted by the objects in the observed scene, the combination of these two sensors for close range applications is independent from external illumination or textures in the scene. This article is focused on the fusion of data acquired both with a time-of-flight (TOF) camera and a thermal infrared (TIR) camera. As the radiometric behaviour of many objects differs between the near infrared used by the TOF camera and the thermal infrared spectrum, a direct co-registration with feature points in both intensity images leads to a high number of outliers. A fully automatic workflow of the geometric calibration of both cameras and the relative orientation of the camera system with one calibration pattern usable for both spectral bands is presented. Based on the relative orientation, a fusion of the TOF depth image and the TIR image is used for scene segmentation and people detection. An adaptive histogram based depth level segmentation of the 3d point cloud is combined with a thermal intensity based segmentation. The feasibility of the proposed method is demonstrated in an experimental setup with different geometric and radiometric influences that show the benefit of the combination of TOF intensity and depth images and thermal infrared images.

  13. Secondary Electron Focusing to Retain High-Resolution Measurements in Linear-Electric- Field Time-of-Flight Telescopes

    NASA Astrophysics Data System (ADS)

    Gilbert, J. A.; Lundgren, R. A.; Panning, M. H.; Rogacki, S. A.; Zurbuchen, T. H.

    2008-12-01

    Linear-electric-field time-of-flight (LEF TOF) analyzers are useful for space applications of mass spectrometry. Particles pass through a thin Carbon foil and enter the analyzer with one of several charge states, typically different than that of the incident ion. High mass resolution (m/Δ m~ 100) is obtained for positive charge states whose isochronous flight times are not dependent on the particle's energy, while low mass resolution (m/Δ m~ 10) is recorded for charge states that travel straight through the analyzer and are affected by collisional scattering when passing through the Carbon foil. When the flight times of different masses and charge states are recorded by the same anode, it is sometimes difficult to extract the lower-count-rate isochronous measurements. We present a technique for overcoming this issue using a modified instrument geometry combined with a novel position-sensitive detector. This modified geometry of a cylindrically symmetric LEF TOF analyzer has inner electrostatic rings, which focus secondary electrons created by isochronous ion impact. Electrons are guided toward the central area of a position-sensitive serpentine delay line anode, and position and flight time information are processed by a time-to-digital converter in a field-programmable-gate-array chip. Neutrals and negative ions will impact the anode in regions other than the center, and can be separated out by their position. Using these advanced electronics with the modified design, the high-resolution measurement can be extracted from the data as a focused peak at the center of the anode, providing improved measurements without an increase in the instrument size. We report the results from simulations and laboratory measurements used to experimentally confirm the expected performance of this design.

  14. Study of the neutron pulse regularity of a small dense plasma focus device by time of flight measurements

    NASA Astrophysics Data System (ADS)

    Castillo, Fermín; Herrera, Julio; Rangel, José

    2002-11-01

    Plasma foci are well know to be efficient neutron generators, with a great potential for immediate applications. For this purpose, it is particularly important to assess the uniformity of their behaviour, which strongly depends on the geometry details and the materials used in their construction. It has been established that there are competing mechanisms in the neutron generation, that yield both isotropic and anisotropic components. However, the latter, which may be associated to the generation of axial ion-beams has been found to contribute no more than 30the total neutron yield, and less than 10particular device. As a matter of fact, measurements of the ratio of head-on and side-on neutron fluxes have been found to be grossly misleading, since they may be extremely large due to very pronounced anisotropic components, even though they may actually contribute less than 10neutron yield. The isotropic component, on the other hand, can be reasonably described by thermonuclear models, and within the experimental error, allowed by the regularity of the device behaviour, can be properly characterised by side-on measurements. The purpose of this work is to study the regularity of the neutron emissions from a small dense plasma focus (5kJ at 37kV) [1], analysing the time of flight signals from three, side-on, on-line, scintillation detectors. [1] F. Castillo, J.J.E. Herrera, J. Rangel, A. Alfaro, M.A. Maza, V. Sakaguchi, G. Espinosa and J.I. Golzarri, "Neutron Anisotropy and X-ray Production of the FN-II Dense Plasma Focus", Brazilian J. Phys. Vol.32 (2002) 3-12.

  15. An automated gas chromatography time-of-flight mass spectrometry instrument for the quantitative analysis of halocarbons in air

    NASA Astrophysics Data System (ADS)

    Obersteiner, F.; Bönisch, H.; Engel, A.

    2016-01-01

    We present the characterization and application of a new gas chromatography time-of-flight mass spectrometry instrument (GC-TOFMS) for the quantitative analysis of halocarbons in air samples. The setup comprises three fundamental enhancements compared to our earlier work (Hoker et al., 2015): (1) full automation, (2) a mass resolving power R = m/Δm of the TOFMS (Tofwerk AG, Switzerland) increased up to 4000 and (3) a fully accessible data format of the mass spectrometric data. Automation in combination with the accessible data allowed an in-depth characterization of the instrument. Mass accuracy was found to be approximately 5 ppm in mean after automatic recalibration of the mass axis in each measurement. A TOFMS configuration giving R = 3500 was chosen to provide an R-to-sensitivity ratio suitable for our purpose. Calculated detection limits are as low as a few femtograms by means of the accurate mass information. The precision for substance quantification was 0.15 % at the best for an individual measurement and in general mainly determined by the signal-to-noise ratio of the chromatographic peak. Detector non-linearity was found to be insignificant up to a mixing ratio of roughly 150 ppt at 0.5 L sampled volume. At higher concentrations, non-linearities of a few percent were observed (precision level: 0.2 %) but could be attributed to a potential source within the detection system. A straightforward correction for those non-linearities was applied in data processing, again by exploiting the accurate mass information. Based on the overall characterization results, the GC-TOFMS instrument was found to be very well suited for the task of quantitative halocarbon trace gas observation and a big step forward compared to scanning, quadrupole MS with low mass resolving power and a TOFMS technique reported to be non-linear and restricted by a small dynamical range.

  16. The Impact II, a Very High-Resolution Quadrupole Time-of-Flight Instrument (QTOF) for Deep Shotgun Proteomics*

    PubMed Central

    Beck, Scarlet; Michalski, Annette; Raether, Oliver; Lubeck, Markus; Kaspar, Stephanie; Goedecke, Niels; Baessmann, Carsten; Hornburg, Daniel; Meier, Florian; Paron, Igor; Kulak, Nils A.; Cox, Juergen; Mann, Matthias

    2015-01-01

    Hybrid quadrupole time-of-flight (QTOF) mass spectrometry is one of the two major principles used in proteomics. Although based on simple fundamentals, it has over the last decades greatly evolved in terms of achievable resolution, mass accuracy, and dynamic range. The Bruker impact platform of QTOF instruments takes advantage of these developments and here we develop and evaluate the impact II for shotgun proteomics applications. Adaption of our heated liquid chromatography system achieved very narrow peptide elution peaks. The impact II is equipped with a new collision cell with both axial and radial ion ejection, more than doubling ion extraction at high tandem MS frequencies. The new reflectron and detector improve resolving power compared with the previous model up to 80%, i.e. to 40,000 at m/z 1222. We analyzed the ion current from the inlet capillary and found very high transmission (>80%) up to the collision cell. Simulation and measurement indicated 60% transfer into the flight tube. We adapted MaxQuant for QTOF data, improving absolute average mass deviations to better than 1.45 ppm. More than 4800 proteins can be identified in a single run of HeLa digest in a 90 min gradient. The workflow achieved high technical reproducibility (R2 > 0.99) and accurate fold change determination in spike-in experiments in complex mixtures. Using label-free quantification we rapidly quantified haploid against diploid yeast and characterized overall proteome differences in mouse cell lines originating from different tissues. Finally, after high pH reversed-phase fractionation we identified 9515 proteins in a triplicate measurement of HeLa peptide mixture and 11,257 proteins in single measurements of cerebellum—the highest proteome coverage reported with a QTOF instrument so far. PMID:25991688

  17. Production of pions, kaons and protons in pp collisions at sqrt{s}= 900 GeV with ALICE at the LHC

    NASA Astrophysics Data System (ADS)

    Aamodt, K.; Abel, N.; Abeysekara, U.; Abrahantes Quintana, A.; Abramyan, A.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agocs, A. G.; Aguilar Salazar, S.; Ahammed, Z.; Ahmad, A.; Ahmad, N.; Ahn, S. U.; Akimoto, R.; Akindinov, A.; Aleksandrov, D.; Alessandro, B.; Alfaro Molina, R.; Alici, A.; Almaráz Aviña, E.; Alme, J.; Alt, T.; Altini, V.; Altinpinar, S.; Andrei, C.; Andronic, A.; Anelli, G.; Angelov, V.; Anson, C.; Antičić, T.; Antinori, F.; Antinori, S.; Antipin, K.; Antończyk, D.; Antonioli, P.; Anzo, A.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Arceo, R.; Arend, A.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Asryan, A.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Äystö, J.; Azmi, M. D.; Bablok, S.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baldit, A.; Bán, J.; Barbera, R.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Barile, F.; Basile, M.; Basmanov, V.; Bastid, N.; Bathen, B.; Batigne, G.; Batyunya, B.; Baumann, C.; Bearden, I. G.; Becker, B.; Belikov, I.; Bellwied, R.; Belmont-Moreno, E.; Belogianni, A.; Benhabib, L.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdermann, E.; Berdnikov, Y.; Betev, L.; Bhasin, A.; Bhati, A. K.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Bimbot, L.; Biolcati, E.; Blanc, A.; Blanco, F.; Blanco, F.; Blau, D.; Blume, C.; Boccioli, M.; Bock, N.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Bohm, J.; Boldizsár, L.; Bombara, M.; Bombonati, C.; Bondila, M.; Borel, H.; Borisov, A.; Bortolin, C.; Bose, S.; Bosisio, L.; Bossú, F.; Botje, M.; Böttger, S.; Bourdaud, G.; Boyer, B.; Braun, M.; Braun-Munzinger, P.; Bravina, L.; Bregant, M.; Breitner, T.; Bruckner, G.; Brun, R.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Calvo, E.; Camacho, E.; Camerini, P.; Campbell, M.; Canoa Roman, V.; Capitani, G. P.; Romeo, G. Cara; Carena, F.; Carena, W.; Carminati, F.; Casanova Díaz, A.; Caselle, M.; Castillo Castellanos, J.; Castillo Hernandez, J. F.; Catanescu, V.; Cattaruzza, E.; Cavicchioli, C.; Cerello, P.; Chambert, V.; Chang, B.; Chapeland, S.; Charpy, A.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chiavassa, E.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Choi, K.; Chojnacki, M.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chuman, F.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Cobanoglu, O.; Coffin, J.-P.; Coli, S.; Colla, A.; Conesa Balbastre, G.; Conesa del Valle, Z.; Conner, E. S.; Constantin, P.; Contin, G.; Contreras, J. G.; Corrales Morales, Y.; Cormier, T. M.; Cortese, P.; Cortés Maldonado, I.; Cosentino, M. R.; Costa, F.; Cotallo, M. E.; Crescio, E.; Crochet, P.; Cuautle, E.; Cunqueiro, L.; Cussonneau, J.; Dainese, A.; Dalsgaard, H. H.; Danu, A.; Das, I.; Dash, A.; Dash, S.; de Barros, G. O. V.; De Caro, A.; de Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gaspari, M.; de Groot, J.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; De Remigis, R.; de Rooij, R.; de Vaux, G.; Delagrange, H.; Delgado, Y.; Dellacasa, G.; Deloff, A.; Demanov, V.; Dénes, E.; Deppman, A.; D'Erasmo, G.; Derkach, D.; Devaux, A.; Di Bari, D.; Di Giglio, C.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Dialinas, M.; Díaz, L.; Díaz, R.; Dietel, T.; Divià, R.; Djuvsland, Ø.; Dobretsov, V.; Dobrin, A.; Dobrowolski, T.; Dönigus, B.; Domínguez, I.; Don, D. M. M.; Dordic, O.; Dubey, A. K.; Dubuisson, J.; Ducroux, L.; Dupieux, P.; Dutta Majumdar, A. K.; Dutta Majumdar, M. R.; Elia, D.; Emschermann, D.; Engel, H.; Enokizono, A.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evrard, S.; Eyyubova, G.; Fabjan, C. W.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fateev, O.; Fearick, R.; Fedunov, A.; Fehlker, D.; Fekete, V.; Felea, D.; Fenton-Olsen, B.; Feofilov, G.; Téllez, A. Fernández; Ferreiro, E. G.; Ferretti, A.; Ferretti, R.; Figueredo, M. A. S.; Filchagin, S.; Fini, R.; Fionda, F. M.; Fiore, E. M.; Floris, M.; Fodor, Z.; Foertsch, S.; Foka, P.; Fokin, S.; Formenti, F.; Fragiacomo, E.; Fragkiadakis, M.; Frankenfeld, U.; Frolov, A.; Fuchs, U.; Furano, F.; Furget, C.; Fusco Girard, M.; Gaardhøje, J. J.; Gadrat, S.; Gagliardi, M.; Gago, A.; Gallio, M.; Ganoti, P.; Ganti, M. S.; Garabatos, C.; García Trapaga, C.; Gebelein, J.; Gemme, R.; Germain, M.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Giraudo, G.; Giubellino, P.; Gladysz-Dziadus, E.; Glasow, R.; Glässel, P.; Glenn, A.; Jiménez, R. Gómez; González Santos, H.; González-Trueba, L. H.; González-Zamora, P.; Gorbunov, S.; Gorbunov, Y.; Gotovac, S.; Gottschlag, H.; Grabski, V.; Grajcarek, R.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Gros, P.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerra, C.; Guerzoni, B.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.; Gupta, A.; Gupta, R.; Gustafsson, H.-A.; Gutbrod, H.; Haaland, Ø.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hamblen, J.; Han, B. H.; Harris, J. W.; Hartig, M.; Harutyunyan, A.; Hasch, D.; Hasegan, D.; Hatzifotiadou, D.; Hayrapetyan, A.; Heide, M.; Heinz, M.; Helstrup, H.; Herghelegiu, A.; Hernández, C.; Herrera Corral, G.; Herrmann, N.; Hetland, K. F.; Hicks, B.; Hiei, A.; Hille, P. T.; Hippolyte, B.; Horaguchi, T.; Hori, Y.; Hristov, P.; Hřivnáčová, I.; Hu, S.; Huang, M.; Huber, S.; Humanic, T. J.; Hutter, D.; Hwang, D. S.; Ichou, R.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Innocenti, P. G.; Ippolitov, M.; Irfan, M.; Ivan, C.; Ivanov, A.; Ivanov, M.; Ivanov, V.; Iwasaki, T.; Jachołkowski, A.; Jacobs, P.; Jančurová, L.; Jangal, S.; Janik, R.; Jena, C.; Jena, S.; Jirden, L.; Jones, G. T.; Jones, P. G.; Jovanović, P.; Jung, H.; Jung, W.; Jusko, A.; Kaidalov, A. B.; Kalcher, S.; Kaliňák, P.; Kalisky, M.; Kalliokoski, T.; Kalweit, A.; Kamal, A.; Kamermans, R.; Kanaki, K.; Kang, E.; Kang, J. H.; Kapitan, J.; Kaplin, V.; Kapusta, S.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kazantsev, A.; Kebschull, U.; Keidel, R.; Khan, M. M.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Kikola, D.; Kileng, B.; Kim, D. J.; Kim, D. S.; Kim, D. W.; Kim, H. N.; Kim, J.; Kim, J. H.; Kim, J. S.; Kim, M.; Kim, M.; Kim, S. H.; Kim, S.; Kim, Y.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Klay, J. L.; Klein, J.; Klein-Bösing, C.; Kliemant, M.; Klovning, A.; Kluge, A.; Knichel, M. L.; Kniege, S.; Koch, K.; Kolevatov, R.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Konevskih, A.; Kornaś, E.; Kour, R.; Kowalski, M.; Kox, S.; Kozlov, K.; Kral, J.; Králik, I.; Kramer, F.; Kraus, I.; Kravčáková, A.; Krawutschke, T.; Krivda, M.; Krumbhorn, D.; Krus, M.; Kryshen, E.; Krzewicki, M.; Kucheriaev, Y.; Kuhn, C.; Kuijer, P. G.; Kumar, L.; Kumar, N.; Kupczak, R.; Kurashvili, P.; Kurepin, A.; Kurepin, A. N.; Kuryakin, A.; Kushpil, S.; Kushpil, V.; Kutouski, M.; Kvaerno, H.; Kweon, M. J.; Kwon, Y.; La Rocca, P.; Lackner, F.; de Guevara, P. Ladrón; Lafage, V.; Lal, C.; Lara, C.; Larsen, D. T.; Laurenti, G.; Lazzeroni, C.; Le Bornec, Y.; Le Bris, N.; Lee, H.; Lee, K. S.; Lee, S. C.; Lefèvre, F.; Lenhardt, M.; Leistam, L.; Lehnert, J.; Lenti, V.; León, H.; Monzón, I. León; Vargas, H. León; Lévai, P.; Li, X.; Li, Y.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Liu, L.; Loginov, V.; Lohn, S.; Lopez, X.; López Noriega, M.; López-Ramírez, R.; López Torres, E.; Løvhøiden, G.; Lozea Feijo Soares, A.; Lu, S.; Lunardon, M.; Luparello, G.; Luquin, L.; Lutz, J.-R.; Ma, K.; Ma, R.; Madagodahettige-Don, D. M.; Maevskaya, A.; Mager, M.; Mahapatra, D. P.; Maire, A.; Makhlyueva, I.; Mal'Kevich, D.; Malaev, M.; Malagalage, K. J.; Maldonado Cervantes, I.; Malek, M.; Malkiewicz, T.; Malzacher, P.; Mamonov, A.; Manceau, L.; Mangotra, L.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Marín, A.; Martashvili, I.; Martinengo, P.; Martínez Hernández, M. I.; Martínez Davalos, A.; Martínez García, G.; Maruyama, Y.; Marzari Chiesa, A.; Masciocchi, S.; Masera, M.; Masetti, M.; Masoni, A.; Massacrier, L.; Mastromarco, M.; Mastroserio, A.; Matthews, Z. L.; Matyja, A.; Mayani, D.; Mazza, G.; Mazzoni, M. A.; Meddi, F.; Menchaca-Rocha, A.; Mendez Lorenzo, P.; Meoni, M.; Mercado Pérez, J.; Mereu, P.; Miake, Y.; Michalon, A.; Miftakhov, N.; Milano, L.; Milosevic, J.; Minafra, F.; Mischke, A.; Miśkowiec, D.; Mitu, C.; Mizoguchi, K.; Mlynarz, J.; Mohanty, B.; Molnar, L.; Mondal, M. M.; Montaño Zetina, L.; Monteno, M.; Montes, E.; Morando, M.; Moretto, S.; Morsch, A.; Moukhanova, T.; Muccifora, V.; Mudnic, E.; Muhuri, S.; Müller, H.; Munhoz, M. G.; Munoz, J.; Musa, L.; Musso, A.; Nandi, B. K.; Nania, R.; Nappi, E.; Navach, F.; Navin, S.; Nayak, T. K.; Nazarenko, S.; Nazarov, G.; Nedosekin, A.; Nendaz, F.; Newby, J.; Nianine, A.; Nicassio, M.; Nielsen, B. S.; Nikolaev, S.; Nikolic, V.; Nikulin, S.; Nikulin, V.; Nilsen, B. S.; Nilsson, M. S.; Noferini, F.; Nomokonov, P.; Nooren, G.; Novitzky, N.; Nyatha, A.; Nygaard, C.; Nyiri, A.; Nystrand, J.; Ochirov, A.; Odyniec, G.; Oeschler, H.; Oinonen, M.; Okada, K.; Okada, Y.; Oldenburg, M.; Oleniacz, J.; Oppedisano, C.; Orsini, F.; Ortiz Velasquez, A.; Ortona, G.; Oskarsson, A.; Osmic, F.; Österman, L.; Ostrowski, P.; Otterlund, I.; Otwinowski, J.; Øvrebekk, G.; Oyama, K.; Ozawa, K.; Pachmayer, Y.; Pachr, M.; Padilla, F.; Pagano, P.; Paić, G.; Painke, F.; Pajares, C.; Pal, S.; Pal, S. K.; Palaha, A.; Palmeri, A.; Panse, R.; Papikyan, V.; Pappalardo, G. S.; Park, W. J.; Pastirčák, B.; Pastore, C.; Paticchio, V.; Pavlinov, A.; Pawlak, T.; Peitzmann, T.; Pepato, A.; Pereira, H.; Peressounko, D.; Pérez, C.; Perini, D.; Perrino, D.; Peryt, W.; Peschek, J.; Pesci, A.; Peskov, V.; Pestov, Y.; Peters, A. J.; Petráček, V.; Petridis, A.; Petris, M.; Petrov, P.; Petrovici, M.; Petta, C.; Peyré, J.; Piano, S.; Piccotti, A.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Pitz, N.; Piuz, F.; Platt, R.; Płoskoń, M.; Pluta, J.; Pocheptsov, T.; Pochybova, S.; Podesta Lerma, P. L. M.; Poggio, F.; Poghosyan, M. G.; Polák, K.; Polichtchouk, B.; Polozov, P.; Polyakov, V.; Pommeresch, B.; Pop, A.; Posa, F.; Pospíšil, V.; Potukuchi, B.; Pouthas, J.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puddu, G.; Pujahari, P.; Pulvirenti, A.; Punin, A.; Punin, V.; Putiš, M.; Putschke, J.; Quercigh, E.; Rachevski, A.; Rademakers, A.; Radomski, S.; Räihä, T. S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Ramírez Reyes, A.; Rammler, M.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rashevskaya, I.; Rath, S.; Read, K. F.; Real, J. S.; Redlich, K.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Rettig, F.; Revol, J.-P.; Reygers, K.; Ricaud, H.; Riccati, L.; Ricci, R. A.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Rivetti, A.; Cahuantzi, M. Rodriguez; Røed, K.; Röhrich, D.; López, S. Román; Romita, R.; Ronchetti, F.; Rosinský, P.; Rosnet, P.; Rossegger, S.; Rossi, A.; Roukoutakis, F.; Rousseau, S.; Roy, C.; Roy, P.; Rubio-Montero, A. J.; Rui, R.; Rusanov, I.; Russo, G.; Ryabinkin, E.; Rybicki, A.; Sadovsky, S.; Šafařík, K.; Sahoo, R.; Saini, J.; Saiz, P.; Sakata, D.; Salgado, C. A.; Salgueiro Domingues da Silva, R.; Salur, S.; Samanta, T.; Sambyal, S.; Samsonov, V.; Šándor, L.; Sandoval, A.; Sano, M.; Sano, S.; Santo, R.; Santoro, R.; Sarkamo, J.; Saturnini, P.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Schiaua, C.; Schicker, R.; Schindler, H.; Schmidt, C.; Schmidt, H. R.; Schossmaier, K.; Schreiner, S.; Schuchmann, S.; Schukraft, J.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, P. A.; Segato, G.; Semenov, D.; Senyukov, S.; Seo, J.; Serci, S.; Serkin, L.; Serradilla, E.; Sevcenco, A.; Sgura, I.; Shabratova, G.; Shahoyan, R.; Sharkov, G.; Sharma, N.; Sharma, S.; Shigaki, K.; Shimomura, M.; Shtejer, K.; Sibiriak, Y.; Siciliano, M.; Sicking, E.; Siddi, E.; Siemiarczuk, T.; Silenzi, A.; Silvermyr, D.; Simili, E.; Simonetti, G.; Singaraju, R.; Singh, R.; Singhal, V.; Sinha, B. C.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Skjerdal, K.; Smakal, R.; Smirnov, N.; Snellings, R.; Snow, H.; Søgaard, C.; Soloviev, A.; Soltveit, H. K.; Soltz, R.; Sommer, W.; Son, C. W.; Son, H.; Song, M.; Soos, C.; Soramel, F.; Soyk, D.; Spyropoulou-Stassinaki, M.; Srivastava, B. K.; Stachel, J.; Staley, F.; Stan, E.; Stefanek, G.; Stefanini, G.; Steinbeck, T.; Stenlund, E.; Steyn, G.; Stocco, D.; Stock, R.; Stolpovsky, P.; Strmen, P.; Suaide, A. A. P.; Subieta Vásquez, M. A.; Sugitate, T.; Suire, C.; Šumbera, M.; Susa, T.; Swoboda, D.; Symons, J.; Szanto de Toledo, A.; Szarka, I.; Szostak, A.; Szuba, M.; Tadel, M.; Tagridis, C.; Takahara, A.; Takahashi, J.; Tanabe, R.; Tapia Takaki, J. D.; Taureg, H.; Tauro, A.; Tavlet, M.; Tejeda Muñoz, G.; Telesca, A.; Terrevoli, C.; Thäder, J.; Tieulent, R.; Tlusty, D.; Toia, A.; Tolyhy, T.; Torcato de Matos, C.; Torii, H.; Torralba, G.; Toscano, L.; Tosello, F.; Tournaire, A.; Traczyk, T.; Tribedy, P.; Tröger, G.; Truesdale, D.; Trzaska, W. H.; Tsiledakis, G.; Tsilis, E.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Turvey, A.; Tveter, T. S.; Tydesjö, H.; Tywoniuk, K.; Ulery, J.; Ullaland, K.; Uras, A.; Urbán, J.; Urciuoli, G. M.; Usai, G. L.; Vacchi, A.; Vala, M.; Palomo, L. Valencia; Vallero, S.; van der Kolk, N.; Vyvre, P. Vande; van Leeuwen, M.; Vannucci, L.; Vargas, A.; Varma, R.; Vasiliev, A.; Vassiliev, I.; Vasileiou, M.; Vechernin, V.; Venaruzzo, M.; Vercellin, E.; Vergara, S.; Vernet, R.; Verweij, M.; Vetlitskiy, I.; Vickovic, L.; Viesti, G.; Vikhlyantsev, O.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Viyogi, Y. P.; Vodopianov, A.; Voloshin, K.; Voloshin, S.; Volpe, G.; von Haller, B.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Wagner, B.; Wagner, V.; Wallet, L.; Wan, R.; Wang, D.; Wang, Y.; Wang, Y.; Watanabe, K.; Wen, Q.; Wessels, J.; Westerhoff, U.; Wiechula, J.; Wikne, J.; Wilk, A.; Wilk, G.; Williams, M. C. S.; Willis, N.; Windelband, B.; Xu, C.; Yang, C.; Yang, H.; Yasnopolskiy, S.; Yermia, F.; Yi, J.; Yin, Z.; Yokoyama, H.; Yoo, I.-K.; Yuan, X.; Yurevich, V.; Yushmanov, I.; Zabrodin, E.; Zagreev, B.; Zalite, A.; Zampolli, C.; Zanevsky, Y.; Zaporozhets, S.; Zarochentsev, A.; Závada, P.; Zbroszczyk, H.; Zelnicek, P.; Zenin, A.; Zepeda, A.; Zgura, I.; Zhalov, M.; Zhang, X.; Zhou, D.; Zhou, S.; Zhu, J.; Zichichi, A.; Zinchenko, A.; Zinovjev, G.; Zoccarato, Y.; Zycháček, V.; Zynovyev, M.

    2011-06-01

    The production of π +, π -, K+, K-, p, and overline{p} at mid-rapidity has been measured in proton-proton collisions at sqrt{s} = 900 GeV with the ALICE detector. Particle identification is performed using the specific energy loss in the inner tracking silicon detector and the time projection chamber. In addition, time-of-flight information is used to identify hadrons at higher momenta. Finally, the distinctive kink topology of the weak decay of charged kaons is used for an alternative measurement of the kaon transverse momentum ( p t) spectra. Since these various particle identification tools give the best separation capabilities over different momentum ranges, the results are combined to extract spectra from p t=100 MeV/ c to 2.5 GeV/ c. The measured spectra are further compared with QCD-inspired models which yield a poor description. The total yields and the mean p t are compared with previous measurements, and the trends as a function of collision energy are discussed.

  18. Results from a 20 scintillator bar time-of-flight test system located inside the 1.4 T CDF solenoid

    NASA Astrophysics Data System (ADS)

    Ukegawa, F.; Heinrich, J. G.; Lockyer, N. S.; Long, O.; Kononenko, W.; Gao, T.; Newcomer, F. M.; Van Berg, R.; Kephart, R.; Mori, S.; Kondo, K.

    2000-01-01

    This paper reports on a test time-of-flight (TOF) system that operated in the Collider Detector at Fermilab (CDF) during pp¯ Tevatron collider operation at s=1.8 TeV in the fall 1995 running period. The TOF system consisted of 20 130×4×4 cm3 long Bicron BC408 scintillator bars, with each end of the bars fitted with a small compound parabolic concentrator and a 16-stage R5946 Hamamatsu fine-mesh photomultiplier. The electronics chain consisted of a custom designed preamplifier, constant fraction discriminator, and commercial TDC and ADC FASTBUS modules read out with the CDF data acquisition system. The counters were installed between the Central Tracking Chamber and the 1.4 T superconducting solenoid at a mean radius of 140 cm. We report a procedure for calculating the t0 time from all tracks in an event, the timing resolution, and the particle identification performance of this system.

  19. High mass resolution, high angular acceptance time-of-flight mass spectroscopy for planetary missions under the Planetary Instrument Definition and Development Program (PIDDP)

    NASA Technical Reports Server (NTRS)

    Young, David T.

    1991-01-01

    This final report covers three years and several phases of work in which instrumentation for the Planetary Instrument Definition and Development Program (PIDDP) were successfully developed. There were two main thrusts to this research: (1) to develop and test methods for electrostatically scanning detector field-of-views, and (2) to improve the mass resolution of plasma mass spectrometers to M/delta M approximately 25, their field-of-view (FOV) to 360 degrees, and their E-range to cover approximately 1 eV to 50 keV. Prototypes of two different approaches to electrostatic scanning were built and tested. The Isochronous time-of-flight (TOF) and the linear electric field 3D TOF devices were examined.

  20. Estimation of angular distribution of neutron dose using time-of-flight for 19F+Al system at 110 MeV

    NASA Astrophysics Data System (ADS)

    Nandy, Maitreyee; Sunil, C.; Maiti, Moumita; Palit, R.; Sarkar, P. K.

    2007-06-01

    We have reported measured angular and energy distributions of neutron dose from 110 MeV 19F projectiles bombarding a thick aluminum target. The measurements are carried out with BC501 liquid scintillator detector using the time-of-flight technique. We have measured neutron energy distributions at 0∘, 30∘, 60∘, 90∘, and 120∘ and converted them to dose distributions using the ICRP recommended fluence to ambient dose equivalent and absorbed dose conversion coefficients. Similar conversions to ambient dose equivalent are done for theoretically estimated distributions from the nuclear reaction model code EMPIRE-2.18. The experimental results are compared with calculated ambient dose equivalent from different empirical formulations proposed by earlier workers. Based on the comparison, we have attempted modifications of the parameters in these empirical expressions.

  1. HYSPEC : A CRYSTAL TIME OF FLIGHT HYBRID SPECTROMETER FOR THE SPALLATION NEUTRON SOURCE.

    SciTech Connect

    SHAPIRO,S.M.; ZALIZNYAK,I.A.

    2002-12-30

    This document lays out a proposal by the Instrument Development Team (IDT) composed of scientists from leading Universities and National Laboratories to design and build a conceptually new high-flux inelastic neutron spectrometer at the pulsed Spallation Neutron Source (SNS) at Oak Ridge. This instrument is intended to supply users of the SNS and scientific community, of which the IDT is an integral part, with a platform for ground-breaking investigations of the low-energy atomic-scale dynamical properties of crystalline solids. It is also planned that the proposed instrument will be equipped with a polarization analysis capability, therefore becoming the first polarized beam inelastic spectrometer in the SNS instrument suite, and the first successful polarized beam inelastic instrument at a pulsed spallation source worldwide. The proposed instrument is designed primarily for inelastic and elastic neutron spectroscopy of single crystals. In fact, the most informative neutron scattering studies of the dynamical properties of solids nearly always require single crystal samples, and they are almost invariably flux-limited. In addition, in measurements with polarization analysis the available flux is reduced through selection of the particular neutron polarization, which puts even more stringent limits on the feasibility of a particular experiment. To date, these investigations have mostly been carried out on crystal spectrometers at high-flux reactors, which usually employ focusing Bragg optics to concentrate the neutron beam on a typically small sample. Construction at Oak Ridge of the high-luminosity spallation neutron source, which will provide intense pulsed neutron beams with time-averaged fluxes equal to those at medium-flux reactors, opens entirely new opportunities for single crystal neutron spectroscopy. Drawing upon experience acquired during decades of studies with both crystal and time-of-flight (TOF) spectrometers, the IDT has developed a conceptual

  2. Characterization Of Nuclear Materials Using Time-Of-Flight ICP-MS

    SciTech Connect

    Buerger, Stefan; Riciputi, Lee R; Bostick, Debra A; Duckworth, Douglas {Doug} C

    2006-01-01

    The investigation of illicit trafficking of nuclear materials, nuclear safeguards analysis, and non-proliferation control requires sensitive and isotope-selective detection methods to gain crucial nuclear forensic information like isotope 'fingerprints' and multi-element signatures. The advantage of time-of-flight (TOF) mass spectrometry - quasi-simultaneous multi-mass analysis - combined with an inductively coupled plasma (ICP) ion source provides an analytical instrument with multi-element and multi-isotope capability and good detection limits. A TOF-ICP-MS system thus appears to be an advantageous choice for the investigation and characterization of nuclear materials. We present here results using a GBC OptiMass 8000 time-of-flight ICP-MS for the isotope screening of solid samples by laser ablation and the multi-element determination of impurities in uranium ore concentrates using matrix matched standards. A laser ablation system (New Wave Research, UP 213) coupled to the TOF-ICP-MS instrument has been used to optimize the system for analysis of non-radioactive metal samples of natural isotopic composition for a variety of elements including Cu, Sr, Zr, Mo, Cd, In, Ba, Ta, W, Re, Pt, and Pb in pure metals, alloys, and glasses to explore precision, accuracy, and detection limits. Similar methods were then applied to measure uranium. When the laser system is optimized, no mass bias correction is required. Precision and accuracy for the determination of the isotopic composition is typically 1 - 3% for elemental concentrations of as little as 50 ppm in the matrix, with no requirement for sample preparation. The laser ablation precision and accuracy are within ~10x of the instrumental limits for liquid analysis (0.1%). We have investigated the capabilities of the TOF-ICP-MS for the analysis of impurities in uranium matrices. Matrix matching has been used to develop calibration curves for a range of impurities (alkaline, earth-alkaline, transition metals, and rare

  3. Phase Separation and Development of a Scanning Time of Flight Microscope to Study Charge Transport in Structured Organic Semiconductors

    NASA Astrophysics Data System (ADS)

    Paul, Sanjoy; Tripathi, Suvagata; Singh, Gautam; Twieg, Robert; Kumar, Satyendra; Ellman, Brett

    2015-03-01

    A scanning time-of-flight microscope (STOFm) has been developed to study charge transport in liquid crystalline organic semiconductors (LCOSCs). The STOFm combines the well-known pulsed laser time-of-flight technique with simultaneous polarized light transmission measurements, both on length scales of ~ 10 μm. In parallel, we have fabricated devices via photopolymerization and phase separation of a monomer/LCOSC mixture. The resulting structure has the LCOSC confined to small regions separated by an insulating polymer. We will discuss fabrication of these systems, as well as their characterization using the STOFm. Finally, we will show results on position-dependent charge transport in various pure LCOSC samples.

  4. Time-of-flight accurate mass spectrometry identification of quinoline alkaloids in honey.

    PubMed

    Rodríguez-Cabo, Tamara; Moniruzzaman, Mohammed; Rodríguez, Isaac; Ramil, María; Cela, Rafael; Gan, Siew Hua

    2015-08-01

    Time-of-flight accurate mass spectrometry (TOF-MS), following a previous chromatographic (gas or liquid chromatography) separation step, is applied to the identification and structural elucidation of quinoline-like alkaloids in honey. Both electron ionization (EI) MS and positive electrospray (ESI+) MS spectra afforded the molecular ions (M(.+) and M+H(+), respectively) of target compounds with mass errors below 5 mDa. Scan EI-MS and product ion scan ESI-MS/MS spectra permitted confirmation of the existence of a quinoline ring in the structures of the candidate compounds. Also, the observed fragmentation patterns were useful to discriminate between quinoline derivatives having the same empirical formula but different functionalities, such as aldoximes and amides. In the particular case of phenylquinolines, ESI-MS/MS spectra provided valuable clues regarding the position of the phenyl moiety attached to the quinoline ring. The aforementioned spectral information, combined with retention times matching, led to the identification of quinoline and five quinoline derivatives, substituted at carbon number 4, in honey samples. An isomer of phenyquinoline was also noticed; however, its exact structure could not be established. Liquid-liquid microextraction and gas chromatography (GC) TOF-MS were applied to the screening of the aforementioned compounds in a total of 62 honeys. Species displaying higher occurrence frequencies were 4-quinolinecarbonitrile, 4-quinolinecarboxaldehyde, 4-quinolinealdoxime, and the phenylquinoline isomer. The Pearson test revealed strong correlations among the first three compounds. PMID:26041455

  5. Detection and quantification of pipe damage from change in time of flight and phase.

    PubMed

    Amjad, Umar; Yadav, Susheel K; Kundu, Tribikram

    2015-09-01

    The use of ultrasonic guided waves for damage detection in pipes is continuously increasing. Generally longitudinal (axial symmetric) modes are excited and detected by PZT (Lead Zirconate Titanate) transducers in transmission mode for this purpose. In most studies the change in the received signal strength with the extent of damage has been investigated while in this study the change in the phase and the time-of-flight (TOF) of the propagating wave modes with the damage size is investigated. The cross-correlation technique is used to record the small changes in the TOF as the damage size varies in steel pipes. Dispersion curves are calculated to carefully identify the propagating wave modes. Differential TOF is recorded and compared for different propagating wave modes. Feature extraction techniques are used for extracting phase and time-frequency information. The main advantage of this approach is that unlike the recorded signal strength the TOF and the phase are not affected by the bonding condition between the transducer and the pipe. Therefore, if the pipe is not damaged but the transducer-pipe bonding is deteriorated then although the received signal strength is altered the TOF and phase remain same avoiding the false positive alarms of damage. PMID:26096882

  6. Multiple-reflection time-of-flight mass spectrometry for in situ applications

    NASA Astrophysics Data System (ADS)

    Dickel, T.; Plaß, W. R.; Lang, J.; Ebert, J.; Geissel, H.; Haettner, E.; Jesch, C.; Lippert, W.; Petrick, M.; Scheidenberger, C.; Yavor, M. I.

    2013-12-01

    Multiple-reflection time-of-flight mass spectrometers (MR-TOF-MS) have recently been installed at different low-energy radioactive ion beam facilities. They are used as isobar separators with high ion capacity and as mass spectrometers with high mass resolving power and accuracy for short-lived nuclei. Furthermore, MR-TOF-MS have a huge potential for applications in other fields, such as chemistry, biology, medicine, space science, and homeland security. The development, commissioning and results of an MR-TOF-MS is presented, which serves as proof-of-principle to show that very high mass resolving powers (∼105) can be achieved in a compact device (length ∼30 cm). Based on this work, an MR-TOF-MS for in situ application has been designed. For the first time, this device combines very high mass resolving power (>105), mobility, and an atmospheric pressure inlet in one instrument. It will enable in situ measurements without sample preparation at very high mass accuracy. Envisaged applications of this mobile MR-TOF-MS are discussed.

  7. LSO background radiation as a transmission source using time of flight.

    PubMed

    Rothfuss, Harold; Panin, Vladimir; Moor, Andrew; Young, John; Hong, Inki; Michel, Christian; Hamill, James; Casey, Michael

    2014-09-21

    LSO scintillators (Lu2Sio5:Ce) have a background radiation which originates from the isotope Lu-176 that is present in natural occurring lutetium. The decay that occurs in this isotope is a beta decay that is in coincidence with cascade gamma emissions with energies of 307,202 and 88 keV. The coincidental nature of the beta decay with the gamma emissions allow for separation of emission data originating from a positron annihilation event from transmission type data from the Lu-176 beta decay. By using the time of flight information, and information of the chord length between two LSO pixels in coincidence as a result of a beta emission and emitted gamma, a second time window can be set to observe transmission events simultaneously to emission events. Using the time when the PET scanner is not actively acquiring positron emission data, a continuous blank can be acquired and used to reconstruct a transmission image. With this blank and the measured transmission data, a transmission image can be reconstructed. This reconstructed transmission image can be used to perform emission data corrections such as attenuation correction and scatter corrections or starting images for algorithms that estimate emission and attenuation simultaneously. It is observed that the flux of the background activity is high enough to create useful transmission images with an acquisition time of 10 min. PMID:25163423

  8. Time of flight measurements based on FPGA using a breast dedicated PET

    NASA Astrophysics Data System (ADS)

    Aguilar, A.; García-Olcina, R.; Martos, J.; Soret, J.; Torres, J.; Benlloch, J. M.; González, A. J.; Sánchez, F.

    2014-05-01

    In this work the implementation of a Time-to-Digital Converter (TDC) using a Nutt delay line FPGA-based and applied on a Positron Emission Tomography (PET) device is going to be presented in order to check the system's suitability for Time of Flight (TOF) measurements. In recent years, FPGAs have shown great advantages for precise time measurements in PET. The architecture employed for these measurements is described in detail. The system developed was tested on a dedicated breast PET prototype, composed of LYSO crystals and Positive Sensitive Photomultipliers (PSPMTs). Two distinct experiments were carried out for this purpose. In the first test, system linearity was evaluated in order to calibrate the time measurements, providing a linearity error of less than 2% and an average time resolution of 1.4 ns FWHM. The second set of measurements tested system resolution, resulting in a FWHM as good as 1.35 ns. The results suggest that the coincidence window for the current PET can be reduced in order to minimize the random events and thus, achieve better image quality.

  9. Development of a Portable Single Photon Ionization-Photoelectron Ionization Time-of-Flight Mass Spectrometer

    PubMed Central

    Huang, Yunguang; Li, Jinxu; Tang, Bin; Zhu, Liping; Hou, Keyong; Li, Haiyang

    2015-01-01

    A vacuum ultraviolet lamp based single photon ionization- (SPI-) photoelectron ionization (PEI) portable reflecting time-of-flight mass spectrometer (TOFMS) was designed for online monitoring gas samples. It has a dual mode ionization source: SPI for analyte with ionization energy (IE) below 10.6 eV and PEI for IE higher than 10.6 eV. Two kinds of sampling inlets, a capillary inlet and a membrane inlet, are utilized for high concentration and trace volatile organic compounds, respectively. A mass resolution of 1100 at m/z 64 has been obtained with a total size of 40 × 31 × 29 cm, the weight is 27 kg, and the power consumption is only 70 W. A mixture of benzene, toluene, and xylene (BTX), SO2, and discharging products of SF6 were used to test its performance, and the result showed that the limit of quantitation for BTX is as low as 5 ppbv (S/N = 10 : 1) with linear dynamic ranges greater than four orders of magnitude. The portable TOFMS was also evaluated by analyzing volatile organic compounds from wine and decomposition products of SF6 inside of a gas-insulated switchgear. PMID:26587023

  10. Studies of Oxide Glass Structure Using Laser Ionization Time of Flight Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Affatigato, Mario

    2004-03-01

    We report on our work determining the structure of glass systems using a new technique, laser photoionization time of flight mass spectroscopy. This technique uses gentle laser desorption from nitrogen (337.1 nm, 100 µJ pulse) or Nd:YAG (266 nm, 100 µJ/pulse) lasers to remove structural units from the glass sample, and is especially well suited for looking at the intermediate range structures present in the glass. We will present our results on the lead borates, lead silicates, lead borosilicates, bismuth borates and gallates, and others where we have observed mesostructural units. We will focus on the insights the technique has yielded regarding question on the sharing of alkali, the mixing of borate- and silicate- networks, the presence of clusters and crystalline units, and the identification and compositional persistence of larger mesostructural units. Complementary work on laser damage from nitrogen and Nd:YAG lasers to our samples and doping with chromophores to aid the technique will also be presented. Given the novelty of the instrument, we will also discuss how our results match those of other, more established techniques such as NMR, Raman, FTIR, and neutron scattering, and also the limitations of the instrument. This work was supported by the National Science Foundation under grant DMR-CER-PECASE 9733724, and by Coe College.

  11. Detection of brake wear aerosols by aerosol time-of-flight mass spectrometry

    NASA Astrophysics Data System (ADS)

    Beddows, D. C. S.; Dall'Osto, M.; Olatunbosun, O. A.; Harrison, Roy M.

    2016-03-01

    Brake dust particles were characterised using an Aerosol Time-of-Flight Mass Spectrometer (ATOFMS) operated using two inlet configurations, namely the aerodynamic lens (AFL) inlet and countersunk nozzle inlet. Laboratory studies show that dust particles are characterised by mass spectra containing ions deriving from Fe and Ba and although highly correlated to each other, the Fe and Ba signals were mostly detected using the nozzle inlet with relatively high laser desorption energies. When using the AFL, only [56Fe] and [-88FeO2] ions were observed in brake dust spectra generated using lower laser desorption pulse energies, and only above 0.75 mJ was the [138Ba] ion detected. When used with the preferred nozzle inlet configuration, the [-88FeO2] peak was considered to be the more reliable tracer peak, because it is not present in other types of dust (mineral, tyre, Saharan etc). As shown by the comparison with ambient data from a number of locations, the aerodynamic lens is not as efficient in detecting brake wear particles, with less than 1% of sampled particles attributed to brake wear. Five field campaigns within Birmingham (background, roadside (3) and road tunnel) used the nozzle inlet and showed that dust particles (crustal and road) accounted for between 3.1 and 65.9% of the particles detected, with the remaining particles being made up from varying percentages of other constituents.

  12. Shock tube/time-of-flight mass spectrometer for high temperature kinetic studies

    SciTech Connect

    Tranter, Robert S.; Giri, Binod R.; Kiefer, John H.

    2007-03-15

    A shock tube (ST) with online, time-of-flight mass spectrometric (TOF-MS) detection has been constructed for the study of elementary reactions at high temperature. The ST and TOF-MS are coupled by a differentially pumped molecular beam sampling interface, which ensures that the samples entering the TOF-MS are not contaminated by gases drawn from the cold end wall thermal boundary layer in the ST. Additionally, the interface allows a large range of postshock pressures to be used in the shock tube while maintaining high vacuum in the TOF-MS. The apparatus and the details of the sampling system are described along with an analysis in which cooling of the sampled gases and minimization of thermal boundary layer effects are discussed. The accuracy of kinetic measurements made with the apparatus has been tested by investigating the thermal unimolecular dissociation of cyclohexene to ethylene and 1,3-butadiene, a well characterized reaction for which considerable literature data that are in good agreement exist. The experiments were performed at nominal reflected shock wave pressures of 600 and 1300 Torr, and temperatures ranging from 1260 to 1430 K. The rate coefficients obtained are compared with the earlier shock tube studies and are found to be in very good agreement. As expected no significant difference is observed in the rate constant between pressures of 600 and 1300 Torr.

  13. Effect of Coulomb interaction on time of flight of cold antiprotons launched from an ion trap

    NASA Technical Reports Server (NTRS)

    Camp, J. B.; Witteborn, F. C.

    1993-01-01

    Time-of-flight spectra for Maxwell-Boltzman (MB) distributions of antiprotons initially held in an ion trap and detected after being launched through a 50-cm-long shielding drift tube have been calculated. The distributions used are of temperature 0.4-40 K, cubic length 0.003-3.0 cm, and number 10-100 particles. The mutual Coulomb repulsion of the particles causes a reduction in the number of late arrival particles expected from the MB velocity distribution. The Coulomb energy is not equally divided among the particles during the expansion. The energy is transferred preferentially to the outer particles so that the reduction in the number of slow particles is not necessarily large. The reduction factor is found to be greater than unity when the potential energy of the trapped ions is greater than about 5 percent of the ions' kinetic energy and is about 2 for the launch parameters of the Los Alamos antiproton gravity experiment.

  14. Development and investigation of a long-range time-of-flight and color imaging system.

    PubMed

    Langmann, Benjamin; Weihs, Wolfgang; Hartmann, Klaus; Loffeld, Otmar

    2014-08-01

    Time-of-flight (Tof) imaging based on the photonic mixer device (PMD) or similar ToF imaging solutions has been limited to short distances in the past, due to limited lighting devices and low sensitivity of ToF imaging chips. Long-range distance measurements are typically the domain of laser scanning systems. In this paper, PMD based medium- and long-range lighting devices working together with a 2-D/3-D camera are presented and several measurement results are discussed. The proposed imaging systems suffer from two systematic limitations in addition to problems due to wind and insufficient lighting: a low lateral resolution of the depth imaging chip and ambiguities in the distance measurements. In order to provide a robust and flexible system, we introduce algorithms to obtain unambiguous depth values (phase unwrapping) and to perform a joint motion compensation and super-resolution. Several experiments were conducted in order to evaluate the components of the multimodal imaging system. PMID:24235261

  15. X-ray laser-induced time-of-flight photoelectron spectroscopy

    NASA Astrophysics Data System (ADS)

    Nelson, Art J.; Dunn, James; van Buuren, Tony W.; Hunter, Jim; Smith, Ray F.; Hemmers, Oliver; Lindle, Dennis W.

    2003-12-01

    X-ray laser induced time-of-flight photoelectron spectroscopy has been used to probe the core-level and valence band electronic structure of room-temperature bulk materials with picosecond time resolution. The LLNL COMET compact tabletop x-ray laser source provides the necessary high photon flux, high energy, monochromaticity, picosecond pulse duration, and coherence for probing ultrafast changes in the chemical and electronic structure of these materials. Valence band and core-level spectra were recorded for transition metal surfaces. In situ sputter etching with Ar ions at 30° incidence will be implemented to improve the surface purity and consequently increase core-level and valence-band photoemission intensity. This work demonstrates a powerful new technique for probing reaction dynamics and for probing changes of local order on surfaces on their fundamental timescales. Future work will include the study of fundamental phenomena such as non-thermal melting, chemical bond formation, intermediate reaction steps, and the existence of transient reaction products.

  16. Acoustic tweezers via sub–time-of-flight regime surface acoustic waves

    PubMed Central

    Collins, David J.; Devendran, Citsabehsan; Ma, Zhichao; Ng, Jia Wei; Neild, Adrian; Ai, Ye

    2016-01-01

    Micrometer-scale acoustic waves are highly useful for refined optomechanical and acoustofluidic manipulation, where these fields are spatially localized along the transducer aperture but not along the acoustic propagation direction. In the case of acoustic tweezers, such a conventional acoustic standing wave results in particle and cell patterning across the entire width of a microfluidic channel, preventing selective trapping. We demonstrate the use of nanosecond-scale pulsed surface acoustic waves (SAWs) with a pulse period that is less than the time of flight between opposing transducers to generate localized time-averaged patterning regions while using conventional electrode structures. These nodal positions can be readily and arbitrarily positioned in two dimensions and within the patterning region itself through the imposition of pulse delays, frequency modulation, and phase shifts. This straightforward concept adds new spatial dimensions to which acoustic fields can be localized in SAW applications in a manner analogous to optical tweezers, including spatially selective acoustic tweezers and optical waveguides. PMID:27453940

  17. Robot navigation and obstacle detection in pipelines using time-of-flight imagery

    NASA Astrophysics Data System (ADS)

    Thielemann, Jens T.; Breivik, Gøril M.; Berge, Asbjørn

    2010-02-01

    Range imagery provided by time-of-flight (TOF) cameras has been shown to be useful to facilitate robot navigation in several applications. Visual navigation for autonomous pipeline inspection robots is a special case of such a task, where the cramped operating environment influences the range measurements in a detrimental way. Inherent in the imaging system are also several defects that will lead to a smearing of range measurements. This paper sketches an approach for using TOF cameras as a visual navigation aid in pipelines, and addresses the challenges concerning the inherent defects in the imaging system and the impact of the operating environment. New results on our previously proposed strategy for detecting and tracking possible landmarks and obstacles in pipelines are presented. We consider an explicit model for correcting lens distortions, and use this to explain why the cylindrical pipe is perceived as a cone. A simplified model, which implicitly handles the combined effects of the environment and the camera on the measured ranges by adjusting for the conical shape, is used to map the robot's environment into an along-axis-view relative to the pipe, which facilitates obstacle traversal. Experiments using a model pipeline and a prototype camera rig are presented.

  18. Intracranial aneurysms: Diagnostics accuracy of three-dimensional, fourier transform, time-of-flight MR angiography

    SciTech Connect

    Korogi, Yukunori; Takahashi, Mutsumasa; Mabuchi, Nobuhisa; Miki, Hitoshi; Fujiwara, Satoru; Horikawa, Yoshiharu; Nakagawa, Toshio; O`Uchi, Toshihiro; Watabe, Tsuneya; Shiga, Hayao

    1994-10-01

    To assess the accuracy of three-dimensional, Fourier transform, time-of-flight magnetic resonance (MR) angiography in the identification of intracranial aneurysms. MR angiograms of 126 patients (59 male and 67 female patients, aged 12-77 years) with various intracranial vascular lesions were evaluated. Seventy-eight aneurysms, including 60 less than 5 mm in diameter, in 61 patients were depicted at conventional angiography. Eight projection images, as well as one axial collapsed MR angiogram obtained with a maximum-intensity projection algorithm, were used for evaluation. Sensitivity for the five observers ranged from 58% to 68% (mean, 63%). Higher sensitivity was achieved for anterior communicating and middle cerebral artery aneurysms, while that for internal carotid artery aneurysms was poor. Sensitivities for small and medium aneurysms ranged from 50% to 60% (mean, 56%) and from 77% to 94% (mean, 85%), respectively. MR angiography can depict intracranial aneurysms 5 mm or larger with good accuracy but is less useful for the identification of smaller aneurysms. 12 refs., 5 figs., 5 tabs.

  19. A novel method for digital ultrasonic time-of-flight measurement

    NASA Astrophysics Data System (ADS)

    Wang, X. F.; Tang, Z. A.

    2010-10-01

    Most ultrasonic ranging measurements are based on the determination of the ultrasonic time-of-flight (TOF). This paper develops a novel method for the TOF measurement which combines both the improved self-interference driving technique and the optional optimization signal processing algorithms. By stimulating the transmitter with the amplitude modulation and the phase modulation envelope square waveforms (APESWs), the proposed system can effectively reduce the errors caused by inertia delay and amplitude attenuation. In addition, based on different signal-to-noise ratio test conditions, the resultant received zero-crossing samples, which are deteriorated by noise, can be precisely inspected and calculated with two optimized algorithms named zero-crossing tracking (ZCT) and time-shifted superposition (TSS) method. The architecture of the designed system is divided into two parts. The novel APESW driving module, the received envelope zero-crossings phase detection module, and the ZCT method processing module are designed in a complex programable logic device. The TSS signal processing module and the optimization algorithm discrimination program module are integrated in a digital signal processor. The TOF measurements calibrated in ultrasonic ranging experiments indicate that the relative errors of the method are limited in ±0.8%. Therefore, a feasible method is provided with the advantages of high noise immunity, accuracy, low cost, and ease of implementation.

  20. Multi-capillary-column proton-transfer-reaction time-of-flight mass spectrometry☆

    PubMed Central

    Ruzsanyi, Veronika; Fischer, Lukas; Herbig, Jens; Ager, Clemes; Amann, Anton

    2013-01-01

    Proton-transfer-reaction time-of-flight mass-spectrometry (PTR-TOFMS) exhibits high selectivity with a resolution of around 5000 m/Δm. While isobars can be separated with this resolution, discrimination of isomeric compounds is usually not possible. The coupling of a multi-capillary column (MCC) with a PTR-TOFMS overcomes these problems as demonstrated in this paper for the ketone isomers 3-heptanone and 2-methyl-3-hexanone and for different aldehydes. Moreover, fragmentation of compounds can be studied in detail which might even improve the identification. LODs for compounds tested are in the range of low ppbv and peak positions of the respective separated substances show good repeatability (RSD of the peak positions <3.2%). Due to its special characteristics, such as isothermal operation, compact size, the MCC setup is suitable to be installed inside the instrument and the overall retention time for a complete spectrum is only a few minutes: this allows near real-time measurements in the optional MCC mode. In contrast to other methods that yield additional separation, such as the use of pre-cursor ions other than H3O+, this method yields additional information without increasing complexity. PMID:24119758