DOCSLIB.ORG

Optimizing Tracking Software for a Time Projection Chamber Wilson H

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Optimizing Tracking Software for a Time Projection Chamber Wilson H Journal of the Arkansas Academy of Science Volume 49 Article 18 1995 Optimizing Tracking Software for a Time Projection Chamber Wilson H. Howe University of Arkansas at Little Rock Christine A. Byrd University of Arkansas at Little Rock Amber D. Climer University of Arkansas at Little Rock Wilfred J. Braithwaite University of Arkansas at Little Rock Jeffrey T. Mitchell Brookhaven National Laboratory Follow this and additional works at: http://scholarworks.uark.edu/jaas Part of the Nuclear Commons Recommended Citation Howe, Wilson H.; Byrd, Christine A.; Climer, Amber D.; Braithwaite, Wilfred J.; and Mitchell, Jeffrey T. (1995) "Optimizing Tracking Software for a Time Projection Chamber," Journal of the Arkansas Academy of Science: Vol. 49 , Article 18. Available at: http://scholarworks.uark.edu/jaas/vol49/iss1/18 This article is available for use under the Creative Commons license: Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0). Users are able to read, download, copy, print, distribute, search, link to the full texts of these articles, or use them for any other lawful purpose, without asking prior permission from the publisher or the author. This Article is brought to you for free and open access by ScholarWorks@UARK. It has been accepted for inclusion in Journal of the Arkansas Academy of Science by an authorized editor of ScholarWorks@UARK. For more information, please contact [email protected], [email protected]. Journal of the Arkansas Academy of Science, Vol. 49 [1995], Art. 18 a Time Projection Chamber Wilson H. Howe, Christine A.Byrd, Amber D. Climer, W.J. Braithwaite Department of Physics and Astronomy University of Arkansas at Little Rock LittleRock, Ar 72204 Jeffrey T.Mitchell Brookhaven National Laboratory Upton, NY11973 Abstract International research collaborations willbe using accelerators in the U.S. and Europe to produce and detect t5 phase transition in high-density nuclear matter called the Quark-Gluon Plasma, formed in collisions between pairs < A=200 nuclei, for projectiles with kinetic energies large compared to their rest mass energies. Each collaboration willus time projection chambers (TPC) to track thousands of secondary charged particles formed in the aftermath of each cen- tral primary collision. Creating and optimizing TPC tracking software is difficultin such a highmultiplicity environment, particularly for particles with a low momentum (below 300 MeV/C). Athigh momenta, energy loss is low enough for par- ticle-tracking to use unchanging helix parameters. However, at low momenta, tracking requires changing helix parameters as energy is lost along the path. Tracking software, written flOrparticles of high momenta, may identify the track of a sin- gle low momentum particle as two or three separate tracks. This tracking problem was corrected by changing the main tracking algorithm to merge together these two-or-three fragmented, low-momentum particle tracks. Event displays were found exceedingly helpful indiagnosing the problems and optimizing the algorithms. Introduction (Pb) beams on a fixed lead target. The second effort is planned at Brookhaven National Laboratory using RHIC Within the first microsecond after the big bang, the (the Relativistic Heavy Ion Collider), where heavy nuclei Standard Model predicts that mass-energy densities were willcollide inpairs. RHIC and its detectors are on sched- so high, the dominant form of matter in the universe was ule for completion by the end of the century (Schukraft, the quark-gluon plasma or QGP (Schukraft, 1993). QGP 1993). is a state in which quarks and gluons move freely at a RHIC is expected to provide the energy necessary to much higher mass-energy density than that of nuclear produce the QGP by colliding gold nuclei, where each is matter. At lower mass-energy density, quarks and gluons moving within 1 part in 20,000 light speed. At such are usually bound together in particles such as protons, speeds, the kinetic energy of each colliding gold nucleus neutrons, pions, etc. Except, possibly, in the cores of neu- is over 100 times its rest mass energy. The Standard tron stars, densities and temperatures do not rise high Model predicts the QGP willbe formed at these high enough to permit quarks and gluons to break free from energy densities, so even ifthe QGP is not formed, these protons and neutrons, so QGP is not readily observed in efforts willprovide a significant test of the Standard nature (Schukraft, 1993). Attempts to produce QGP have Model. been made using the SPS (Super Proton Synchrotron) at AtRHIC, the effort to observe the QGP willbe car- CERN and using the AGS (Alternating Gradient ried out by analyzing the particles emerging from the Synchrotron) at Brookhaven National Laboratory. In aftermath ofcentral collisions between relativistic pairs of each case relativistic nuclei collide with stationary nuclei gold nuclei. Thousands of charged secondary particles, in fixed targets. None of these experiments have reported produced ineach primary collision, willbe used to inves- the detection of the QGP (Schmidt, 1993). tigate the physics of the primary collision. Detectors at Two distinct attempts are now being made to pro- RHIC are being built to track charged particles generated duce the phase transition from normal nuclear matter to in the aftermath of each central primary collision. Several QGP, using relativistic beams of heavy nuclei. One effort, thousand charged secondary particles (called a high mul- which is underway, uses the SPS at CERN to provide lead tiplicity environment) make tracking a difficult experi- Proceedings Arkansas Academy of Science, Vol.49, 1995 75 Published by Arkansas Academy of Science, 1995 75 ? Journal of the Arkansas Academy of Science, Vol. 49 [1995], Art. 18 mental problem. The TPC is a coaxial cylinder, 4.2 meters long, with The Solenoidal Tracker (STAR) is one of two large an outside diameter of 4 meters and an inside diameter instruments located at RHIC at one of its six colliding- of 2 meters. The cylinder is located within the Solenoidal beam crossover points. Secondary charged particles pro- Magnet and around the vertex tracking detector. Particles duced at RHIC are observed using different sub-dectors with momenta greater than 125 MeV / c can make it of STAR, which is made up of a solenoidal magnet con- through the TPC geometry, but tracking lower-momen- taining these sub-detectors. The solenoidal magnet sur- tum particles is left to the vertex detector. The TPC miss- rounds the beam pipe of RHIC, creating a magnetic field es some high momentum particles due to its geometry, (0.5 T) along the beam line. Charged particles willbend but overall it tracks about 50% of the secondary charged in this B-field, and the charge and momentum of these particles created in each central collider event (STAR, particles willbe determined by measuring the curvature 1992). The TPC cylinder is divided inhalf by a high volt- of their tracks. The STAR sub-detectors are being built to age membrane which creates an electric field (130 V / determine pixel-by-pixel coordinates of each particle's tra- cm). The endcaps are made up of rows of pads at low jectory, so all can be tracked simultaneously. potential (1265 V), where the signals for tracking parti- The main sub-detector in STAR is the Time cles are induced. The track density is great near the ver- Projection Chamber (TPC), which measures the trajecto- tex; thus, pads close to the vertex are small (2.85 x 11.5 ries of charged particles in three spatial dimensions. The mm) providing good track separation. TPC pads farther TPC is complemented by several other detectors; these from the vertex are larger (6.2 x 19.5 mm), providing bet- include: a tracker near the collider vertex responsible for ter particle identification (STAR, 1992). measuring all charged particle tracks, especially those The TPC is designed to detect charged particles, with low transverse momentum (below 150 MeV / c) or identify them, and obtain the momentum and charge of short half-lives; trigger detectors for measuring when and each. The TPC can be viewed as electronically "taking a where each gold on gold event occurs; and an three-dimensional picture of the particle trajectories" as Electromagnetic Calorimeter used to measure particle the particles ionize its gas, as seen in Fig. 1. The electric energies (STAR, 1992). field causes the ionization electrons to drift toward the Fig. 1. Ionization electrons are shown drifting toward the endcaps of a Time Projection Chamber, lhe size or the beam pipe is exaggerated. Proceedings Arkansas Academy of Science, Vol.49, 1995 ? ? 76 http://scholarworks.uark.edu/jaas/vol49/iss1/18 76 Journal of the Arkansas Academy of Science, Vol. 49 [1995], Art. 18 ends of the TPC chamber. There the signal from each difficult since their tracks can start anywhere in the TPC electron is amplified at a thin anode wire; a signal is then instead of starting at the vertex. Allparticle tracks do induced on a pad under the wire. The placement of the have common characteristics, and these characteristics signal on the pad gives two coordinates of the track, and are used in designing tracking software. For instance, the drift time gives the third coordinate. Up to 45 (x,y,z) charged particles follow helical paths inmagnetic fields, pixel coordinates may be associated with a single track; so the tracking algorithm uses a helix to link hits into par- tracking software groups these three-dimensional coordi- ticle tracks. nates into particle tracks. The tracking algorithm starts by making groups out Measuring charged particle tracks is important of all the hits on the outside of the TPC. Because of the because these tracks can be used to infer fundamental lower track density, this algorithm begins with the outer- information about the primary central collision which most hit and moves inward toward the vertex.
Load more

Recommended publications
  • Development of a Liquid Xenon Time Projection Chamber for the XENON Dark Matter Search
    Development of a Liquid Xenon Time Projection Chamber for the XENON Dark Matter Search Kaixuan Ni Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Graduate School of Arts and Sciences COLUMBIA UNIVERSITY 2006 c 2006 Kaixuan Ni All rights reserved Development of a Liquid Xenon Time Projection Chamber for the XENON Dark Matter Search Kaixuan Ni Advisor: Professor Elena Aprile Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Graduate School of Arts and Sciences COLUMBIA UNIVERSITY 2006 c 2006 Kaixuan Ni All rights reserved ABSTRACT Development of a Liquid Xenon Time Projection Chamber for the XENON Dark Matter Search Kaixuan Ni This thesis describes the research conducted for the XENON dark matter direct detection experiment. The tiny energy and small cross-section, from the interaction of dark matter particle on the target, requires a low threshold and sufficient background rejection capability of the detector. The XENON experiment uses dual phase technology to detect scintillation and ionization simultaneously from an event in liquid xenon (LXe). The distinct ratio, be- tween scintillation and ionization, for nuclear recoil and electron recoil events provides excellent background rejection potential. The XENON detector is designed to have 3D position sensitivity down to mm scale, which provides additional event information for background rejection. Started in 2002, the XENON project made steady progress in the R&D phase during the past few years. Those include developing sensitive photon detectors in LXe, improving the energy resolution and LXe purity for detect- ing very low energy events.
    [Show full text]
  • Using a Two-Phase Xenon Time Projection Chamber for Improved Background Rejection in Searches for Neutrinoless Double-Beta Decay
    Using a two-phase xenon time projection chamber for improved background rejection in searches for neutrinoless double-beta decay by Callan Jessiman A thesis submitted to the Faculty of Graduate and Postdoctoral Affairs in partial fulfilment of the requirements for the degree of Master of Science in Physics Department of Physics Carleton University Ottawa, Ontario January 2020 c 2020 Callan⃝ Jessiman Abstract The nature of the neutrino masses is an important open question in particle physics; neutrinos were conceived and implemented into the Standard Model as massless, and their masses, now known to be nonzero, represent an area of new physics. Essential to the investigation of this area are mechanisms by which one might measure these masses, including the hypothetical neutrinoless double-beta decay, which has a lifetime related to the neutrino masses. Experiments searching for this rare decay, such as EXO, are impacted heavily by sources of background radiation. Here, a prototype two-phase time projection chamber is described, having superior temporal resolution to the existing EXO architecture. A machine- learning analysis of data from this prototype is used for pulse-shape discrimination, which has the potential to significantly increase EXO's sensitivity; the preliminary efforts described here are able to reduce backgrounds by 94%, while rejecting only 21% of the signal. ii Acknowledgements First, and foremost, I express my gratitude towards my supervisor, David Sinclair, and my colleague Braeden Veenstra. The entire project was of David's devising, as was the leadership that saw it through. Meanwhile, getting the thing to actually work, and extracting results from it, was Braeden's task as much as it was mine.
    [Show full text]
  • Parity Non-Conservation in Atoms L.M
    INIJ. •®'82 Dl OF THE INTERNATIONAL CONFERENCE '82 14-19 JUNE, 1982 BALATONFURED, HUNGARY EDITORS A. FRENKEL LJENIK BUDAPEST, 1982 III. CONTENTS Volume I ! -4- OPENING ADDRESS NEUTRINO OSCILLATION SEARCH FOR NEUTRINO OSCILLATIONS - A PROGRESS REPORT R. L. Mös sbauer 1 SEARCH FOR NEUTRINO OSCILLATION F. Reines Suppl NEUTRINO OSCILLATION EXPERIMENTS ON AMERICAN ACCELERATORS C. Baltay , Suppl PAST AND FUTURE OSCILLATION EXPERIMENTS IN CERN NEUTRINO BEAMS H. Wachsmuth 13 DETECTION OF MATTER EFFECTS ON NEUTRINO OSCILLATIONS BY DUMAND R.J. Oakes 23 LARGE AMPLITUDE NEUTRINO OSCILLATIONS WITH MAJORANA MASS EIGENSTATES? B. Pontecorvo 35 TRULY NEUTRAL MICROOBJECTS AND OSCILLATIONS IN PARTICLE PHYSICS S.M. Bilenky 42 A POSSIBLE TEST OF CP INVARIANCE IN NEUTRINO OSCILLATIONS S.M. Bilenky 46 *Papers labelled "Suppl" are to be found in the Supplement to this Proceedings. Their titles as given here are provisional. IV. NEUTRINO MASS AN EXPERIMENT TO STUDV THE 3-DECAY OF FREE ATOMIC AND MOLECULAR TRITIUM R.G.H. Robertson 51 MEASUREMENT OF THE MASS OF THE ELECTRON NEUTRINO USING THE ELECTRON CAPTURE DECAY PROCESS OF THE NUCLEUS S. Yasumi 59 AN EXPERIMENT TO DETERMINE THE MASS OF THE ELECTRON ANTINEUTRINO R.N. Boyd 67 DETERMINATION OF AN UPPER LIMIT OF THE MASS OF THE MUONIC NEUTRINO FROM THE PION DECAY IN FLIGHT P. Le Coultre , 75 RADIATIVE DECAYS OF DIRAC AND MAJORANA NEUTRINOS (RECENT RESULTS) S.T. Petcov 82 BEAM DUMP PROMPT NEUTRINO OSCILLATION BY 4OO GeV PROTON INTERACTIONS R. J. Loveless 89 A STUDY OF THE FORWARD PRODUCTION OF CHARM STATES AND PROMPT MUONS IN 350 GeV p-Fe AND 278 GeV n~-Fe INTERACTIONS A.
    [Show full text]
  • Design and Construction of the Spirit Tpc
    DESIGN AND CONSTRUCTION OF THE SPIRIT TPC By Suwat Tangwancharoen A DISSERTATION Submitted to Michigan State University in partial fulfillment of the requirements for the degree of Physics-Doctor of Philosophy 2016 ABSTRACT DESIGN AND CONSTRUCTION OF THE SPIRIT TPC By Suwat Tangwancharoen The nuclear symmetry energy, the density dependent term of the nuclear equation of state (EOS), governs important properties of neutron stars and dense nuclear matter. At present, it is largely unconstrained in the supra-saturation density region. This dissertation concerns the design and construction of the SπRIT Time Projection Chamber (SπRIT TPC) at Michigan State University as part of an international collaborations to constrain the symmetry energy at supra-saturation density. The SπRIT TPC has been constructed during the dissertation and transported to Radioactive Isotope Beam Factory (RIBF) at RIKEN, Japan where it will be used in conjunction with the SAMURAI Spectrometer. The detector will measure yield ratios for pions and other light charged particles produced in central collisions of neutron-rich heavy ions such as 132Sn + 124Sn. The dissertation describes the design and solutions to the problem presented by the measurement. This also compares some of the initial fast measurement of the TPC to calculation of the performance characteristics. ACKNOWLEDGMENTS The design and construction of the SAMURAI Pion-Reconstruction and Ion Tracker Time Projection Chamber (SπRIT TPC) involved an international collaboration to study and constrain the symmetry energy term in the nuclear equation of state (EOS) at twice supra- saturation density. The TPC design and construction as well as many additional aspects of the project were supported financially by the U.S.
    [Show full text]
  • 3 Detector Gas 25 3.1 Gas Properties
    DISSERTATION Titel der Dissertation A GEM based Time Projection Chamber prototype for the PANDA¯ experiment - Gas system development and forward tracking studies Verfasser Mag. rer. nat. Philipp Müllner angestrebter akademischer Grad Doktor der Naturwissenschaften (Dr. rer. nat.) Wien, 2012 Studienkennzahl lt. Studienblatt: A 091 411 Dissertationsgebiet lt. Studienblatt: Physik Betreuer: Doz. Dr. Johann Zmeskal 2 Abstract The PANDA¯ collaboration is building a state-of-the-art universal detector for strong interaction studies at the High Energy Storage Ring (HESR) at the new Facility for Antiproton and Ion Research (FAIR) at Darmstadt, Germany. The facility will provide a high intensity, cooled antiproton beam. Together with the advanced particle identification system of the PANDA¯ detector a wide experimental program ranging from QCD studies to funda- mental symmetry tests will be accessible. One of two options for the PANDA¯ central tracker was a Gas Electron Multiplier (GEM) based Time Projection Chamber (TPC). The low ma- terial budget GEM based TPC is an ideal device for 3-dimensional space tracking, which features fulfill the PANDA¯ tracking system requirements, e.g. high rate capability, continuous operation, high momentum resolution, high spatial resolution and full solid coverage. In the course of the detector developments for PANDA,¯ a large GEM- TPC prototype was build and tested at GSI (Darmstadt, Germany) by the GEM-TPC collaboration. Within the framework of this work, an overview of the prototype general design will be given. The main task of my thesis was the development of a closed gas supply system for the large GEM-TPC prototype. The detector requirements made it necessary to build it as closed circulation system with infrastructures for O2 and H2O measurement and purification as well as for precise pressure controlling inside the gas system.
    [Show full text]
  • Time Projection Chamber the LUX Experiment LZ @ SLAC National
    Time Projection Chamber LZ is a liquid-xenon TPC that collects two scintillation signals for each The LZ experiment scattering event. S1 is from the de-excitation of short-lived xenon molecules, or dimers. S2 is from electrons liberated at the event site that The LUX-ZEPLIN search for WIMP dark matter are extracted into the gas phase where they undergo electroluminescence. The S2 hit pattern give the lateral position and the S2-S1 time difference gives the depth. The localization allows for An Inventory of the Universe selection of WIMP candidates only in the detector interior, where wternal In 1933, Fritz Zwicky’s observation and virial radioactive backgrounds do not readily penetrate. analysis of the Coma Cluster of galaxies led to his discovery that most of its the matter Anatomy of LZ was dark. This finding launched a decades Scintillator Detector Feedthroughs long mystery as astronomers since have reinforced his findings time and again. The now Standard Cosmology based on Water independent observations of clusters, the Shield cosmic microwave background and distant Science reach type-1a supernovae converge on a consistent The 2013 Snowmass Community Summer Study’s set of cosmological parameters shown below. Anode & Electron Time Extraction Grids Cosmic Frontier working group on WIMP Dark Matter Big Bang Nucleosynthesis indicates that only Projection Detection (CF1) made a survey of the field, producing 20% of the mass density is composed of Chamber this summary plot, including the world leading LUX ordinary matter. A leading hypothesis is that result and the LZ projection for a 1000-day run. dark matter is composed of Weakly Interacting Massive Particles, or WIMPs.
    [Show full text]
  • Oral Program As of May 27, 2008
    Oral Program as of May 27, 2008 We invite you to Berkeley for the first West Coast meeting of the Symposium on Radiation Measurements and Applications. SORMA West 2008 is hosted jointly by the University of California, Berkeley and the Lawrence Berkeley and Lawrence Livermore National Laboratories. It is made possible by the generosity of our agency sponsors and private-sector supporters. We gratefully acknowledge the cooperation and advice of the original SORMA, now SORMA East, hosted by the University of Michigan and next scheduled for 2010. Note: the Monday opening plenaries (in International House) and Thursday summary or rapporteur plenaries are described in a different document. Monday's plenaries will be held at International House, which is also the location of the poster session and reception. The parallel oral sessions Tuesday through Thursday, and the closing plenary, will be in Stanley Hall (rooms 105 and 106) and Bechtel Engineering Center (Sibley Auditorium). Table of Contents Monday, June 2............................................................................................................................................. 1 Tuesday, June 3 ............................................................................................................................................ 1 New Scintillators........................................................................................................................................ 2 Tuesday AM I: Stanley 105 .................................................................................................................
    [Show full text]
  • Two-Phase Xenon Time Projection Chambers for WIMP Searches and Other Applications
    Two-Phase Xenon Time Projection Chambers for WIMP Searches and Other Applications Nicole A. Larsen Yale University Department of Physics Advisor: Daniel McKinsey Thesis Prospectus May 24, 2012 Abstract Astronomical evidence indicates that 23 % of the energy density in the universe is comprised of some form of non-standard, non-baryonic matter that has yet to be observed. One of the predominant theories is that dark matter consists of WIMPs (Weakly Interacting Massive Particles), so named be- cause they do not interact electromagnetically or through the strong nuclear force. In direct dark matter detection experiments the goal is to look for evidence of collisions between WIMPs and other particles such as heavy nuclei. Here, the challenge is to measure exceedingly rare interactions with very high precision. In recent years xenon has risen as a medium for particle detection, exhibiting a number of desirable qualities that make it well-suited for direct WIMP searches. The LUX (Large Underground Xenon) experiment is a 350-kg xenon-based direct dark matter detection experiment currently deployed at the Homestake Mine in Lead, South Dakota, consisting of a two-phase (liq- uid/gas) xenon time projection chamber with a 100-kg fiducial mass. Its projected sensitivity for 300 days of underground data acquisition is a cross-section of 7 × 10-46 cm2 for a WIMP mass of 100 GeV, representing an improvement of nearly an order of magnitude over previous WIMP-nucleon scattering cross-section limits. Furthermore, two-phase xenon-based technologies are useful in many other applications, in- cluding other fundamental physics searches, imaging of special nuclear materials, and medical imaging.
    [Show full text]
  • The Enriched Xenon Observatory (EXO) Saturday, 11 June 2011 16:20 (20 Minutes)
    TIPP 2011 - 2nd International Conference on Technology and Instrumentation in Particle Physics Contribution ID: 96 Type: Oral Presentation The Enriched Xenon Observatory (EXO) Saturday, 11 June 2011 16:20 (20 minutes) The Enriched Xenon Observatory (EXO) is an experimental program designed to search for the neutrinoless double beta decay (0nbb) of Xe-136. Observation of 0nbb would determine an absolute mass scale for neutri- nos, prove that neutrinos are massive Majorana particles (indistinguishable from their own antiparticles), and constitute physics beyond the Standard Model. The current phase of the experiment, EXO-200, uses 200kgof liquid xenon with 80% enrichment in Xe-136, and also serves as a prototype for a future 1-10 ton scale EXO experiment. The double beta decay of xenon is detected in an ultra-low background time projection chamber (TPC) by collecting both the scintillation light and the ionization charge. The detector is now operational at the Waste Isolation Pilot Plant (WIPP) in New Mexico. It was first run with natural xenon to fully commission it and study its performance. Preparation for physics data taking is underway. The projected two-year sensi- tivity for neutrinoless double beta decay half-life is 6.4E25 y at 90% confidence level. In view of a future ton scale experiment, the collaboration is performing R&D to realize an ideal, background-free search for which the daughter nucleus produced by the double beta decay is also individually detected. In this talk, the current status and preliminary results from EXO-200 will be presented, and prospects for a ton scale EXO experiment will be discussed.
    [Show full text]
  • A Time Projection Chamber As a Gamma-Ray Telescope and Polarimeter
    Performance measurement of HARPO: a Time Projection Chamber as a gamma-ray telescope and polarimeter P. Gros∗1, S. Amano2, D. Atti´e3, P. Baron3, D. Baudin3, D. Bernard1, P. Bruel1, D. Calvet3, P. Colas3, S. Dat´e4, A. Delbart3, M. Frotiny1, Y. Geerebaert1, B. Giebels1, D. G¨otz5, S. Hashimoto2, D. Horan1, T. Kotaka2, M. Louzir1, F. Magniette1, Y. Minamiyama2, S. Miyamoto2, H. Ohkuma4, P. Poilleux1, I. Semeniouk1, P. Sizun3, A. Takemoto2, M. Yamaguchi2, R. Yonamine3, and S. Wangz1 1LLR, Ecole Polytechnique, CNRS/IN2P3, 91128 Palaiseau, France 2LASTI, University of Hy^ogo,Japan 3CEA/Irfu Universit´eParis Saclay, France 4JASRI/SPring8, Japan 5AIM, CEA/DSM-CNRS-Universit´eParis Diderot, France August 31, 2017 Abstract We analyse the performance of a gas time projection chamber (TPC) as a high-performance gamma-ray telescope and polarimeter in the e+e− pair-creation regime. We use data collected at a gamma- arXiv:1706.06483v2 [astro-ph.IM] 30 Aug 2017 ray beam of known polarisation. The TPC provides two orthogonal ∗philippe.gros at in2p3.fr yNow at GEPI, Observatoire de Paris, CNRS, Univ. Paris Diderot, Place Jules Janssen, 92190 Meudon, France zNow at INPAC and Department of Physics and Astronomy, Shanghai Jiao Tong Uni- versity, Shanghai Laboratory for Particle Physics and Cosmology, Shanghai 200240, China 1 projections (x; z) and (y; z) of the tracks induced by each conversion in the gas volume. We use a simple vertex finder in which vertices and pseudo-tracks exiting from them are identified. We study the various contributions to the single-photon angular resolution using Monte Carlo simulations, compare them with the ex- perimental data and find that they are in excellent agreement.
    [Show full text]
  • Micromegas-Based Detectors for Time-Of-Flight Measurements Of
    EPJ Web of Conferences 239, 17007 (2020) https://doi.org/10.1051/epjconf/202023917007 ND2019 MicroMegas-based detectors for time-of-flight measurements of neutron-induced reactions 1, 1 1 2 1 1 1 F. Gunsing ∗, F. Belloni , E. Berthoumieux , M. Diakaki , E. Dupont , E. Ferrer-Ribas , and Th. Papaevangelou 1CEA - Irfu, University Paris-Saclay, F-91191 Gif-sur-Yvette, France 2CEA Cadarache, DEN/DER/SPRC/LEPh, F-13108 St-Paul-Lez-Durance, France Abstract. MicroMegas detectors are versatile gaseous detectors which are used for ionizing particle detection. A MicroMegas detector consists of two adjacent gas-filled volumes. One volume acts as a drift region with an electric field operating in the ionization chamber regime, the second volume is the amplification region acting as a parallel-plate avalanche counter. The use of the microbulk technique allows the production of thin, radiation resistant, and low-mass detector with a highly variable gain. Such MicroMegas detectors have been developed and used in combination with neutron time-of-flight measurements for in-beam neutron-flux monitoring, fission and light-charged particle reaction cross section measurements, and for neutron-beam imaging. An overview of MicroMegas detectors for neutron detection and neutron reaction cross section measurements and related results and developments will be presented. 1 Introduction useful at continuous neutron sources, typically as neutron monitors, but can be further extended to the use at pulsed Since the development of the first prototype, MicroMegas time-of-flight facilities, such as GELINA at JRC-Geel [9], detectors [1] are used in many experiments in nuclear and NFS at GANIL, or n_TOF at CERN [10].
    [Show full text]
  • A Time Projection Chamber with Optical Readout for Charged Particle Track Structure Imaging
    A time projection chamber with optical readout for charged particle track structure imaging U.Titt*+ , A.Breskin#, R.Chechik#, V.Dangendorf *, H.Schmidt-Böcking+, H.Schuhmacher* * Physikalisch-Technische Bundesanstalt, 38116 Braunschweig, Germany + Universität Frankfurt, 60486 Frankfurt, Germany # Weizmann Institute of Science, 76100 Rehovot, Israel Abstract We report about a nuclear track imaging system which is designed to study in detail the ioniza- tion topology of charged particle tracks in a low-pressure gas. The detection method is based on a time projection chamber (TPC) filled with low-pressure triethylamine (TEA). Ionization electrons produced by energetic charged particles are three-dimensionally imaged by recording light from electron avalanches with an intensified CCD system. The detector permits to inves- tigate the spatial ionization distributions of particle tracks in gas, of equivalent length and resolution in tissue of 4 mm and 40 nm (RMS), respectively. We explain the relevance of this technique for dosimetry, describe the experimental method and the basic operation parameters. First results of the chamber response to protons and alpha particles are presented. Keywords: microdosimetry, track imaging, optical read out, TPC, triethylamine, scintillation PACS codes: 8760M, 2940K, 2940M Corresponding author: Volker Dangendorf email: volker.dangendorf @ ptb.de Physikalisch-Technische Bundesanstalt Tel: ++49 (0) 531 592 7525 Bundesallee 100 Fax: ++49 (0) 531 592 7015 38176 Braunschweig 1 1. Introduction or the use of a low-pressure tissue-equivalent pro- Microscopic information about the ionization den- portional counter (TEPC). The latter is able to sity along tracks of charged particles is required in simulate a tissue volume of about 1 mm in diameter various areas.
    [Show full text]