Bulletin of the American Physical Society
3rd Joint Meeting of the APS Division of Nuclear Physics and the Physical Society of Japan
Volume 54, Number 10
Tuesday–Saturday, October 13–17, 2009; Waikoloa, Hawaii
Session CL: Instrumentation II |
Hide Abstracts |
Chair: A. Takatani, RIKEN Room: Queens 6 |
Thursday, October 15, 2009 9:00AM - 9:15AM |
CL.00001: Performance study of a Vertex Drift Chamber (VDC) for the measurement of strangeness photoproduction in the $d (\gamma, K^{0}$) $\Lambda$p reaction Brian Beckford Kaon photoproduction has been used extensively to study the strangeness production mechanism. However, relatively little is known about strangeness production on the neutron, particularly for the production of neutral hyperons ($\Lambda$ or $\Sigma^{0}$). An experiment has been designed at the Laboratory of Nuclear Science of Tohoku University (LNS-Tohoku) which employs the recently upgraded Neutral Kaon Spectrometer 2 (NKS2), to study the $d (\gamma$, $K^{0}$) $\Lambda$p reaction. Recent beam time at the LNS was used to commission the latest version of the NKS2 detector system. The VDC is included in order to the measure the invariant mass of the $K_{s}^{0}$ and $\Lambda$, in coincidence. Thus, avoiding the Fermi motion effect in the cross-section calculation; a determination of both invariant masses requires the four-track reconstruction of the reaction vertex. It is composed of 8 layers with wires placed only at stereo angles, resulting in an approximately 4 mm half-cell size. Preliminary tests have yielded a layer efficiency of 99{\%} in the HV operating range of 2100-2150 V, and for a threshold range of 2.0-6.0 V for all layers. The motivation for the upgrade, experimental technique and preliminary results will be presented. [Preview Abstract] |
Thursday, October 15, 2009 9:15AM - 9:30AM |
CL.00002: Development of the Cylindrical Detector System for an experimental search for kaonic nuclei at J-PARC Fuminori Sakuma The experiment J-PARC E15 searches for the simplest kaonic nuclear bound state, $K^-pp$, by in-flight $^3$He$(K^-,n)$ reaction. To reconstruct invariant mass spectroscopy via the expected decay $K^-pp \to \Lambda p \to p\pi^-p$, the Cylindrical Detector System (CDS) has been constructed at the K1.8BR beam-line in the J-PARC 50GeV PS. The CDS consists of a solenoid magnet, Cylindrical Drift Chamber (CDC) and Cylindrical Detector Hodoscope (CDH) with the invariant-mass resolution via the $K^- pp$ decay of 19 MeV/$c^2$ ($\sigma$). In addition, we are developing a thick-GEM (TGEM) TPC as an inner tracker for the upgrade of the experiment. In this talk, an overview of the detectors and the preparation status will be presented. [Preview Abstract] |
Thursday, October 15, 2009 9:30AM - 9:45AM |
CL.00003: ABSTRACT WITHDRAWN |
Thursday, October 15, 2009 9:45AM - 10:00AM |
CL.00004: Performance of PHENIX Prototype Resistive Plate Chambers Brett Fadem The PHENIX detector is located on the ring of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. Prototype resistive plate chamber (RPC) modules were deployed during the latest RHIC run. The production versions of such modules will form an integral component of an upgrade to the PHENIX muon trigger. As a result of this upgrade, the determination of flavor separated quark and anti-quark distribution functions will be possible using single spin asymmetries of muons created in the parity-violating decay of W bosons. A report on the relative efficiency and timing resolution of the prototype under the $\sqrt{s}$ = 500 GeV beam will be given. [Preview Abstract] |
Thursday, October 15, 2009 10:00AM - 10:15AM |
CL.00005: Assembly and Testing of the Resistive Plate Chamber Upgrade for the PHENIX Muon Arms William Powell Important questions remain to be answered about the origin of the proton spin. A new fast resistive plate chamber (RPC) based trigger system is being developed for the PHENIX muon spectrometer arms that will allow for the first time the measurement of the flavor structure of the quark polarization in the proton through the observations of W-bosons in polarized proton-proton collisions at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The new PHENIX Muon Trigger will improve the efficiency by which the data acquisition system can identify potential W events by approximately two orders of magnitude. W-bosons can be detected through the appearance of a high-energy muon in one of two existing muon spectrometers. The upgrade consists of four detector stations based on RPC technology, and new front-end electronics for the existing muon tracking detectors. Detector modules for one RPC station are currently being assembled and tested. Testing of the module components, completed modules and half octants will be described. Tests results and progress will be reported. [Preview Abstract] |
Thursday, October 15, 2009 10:15AM - 10:30AM |
CL.00006: Development of Fast-Data-Formatting Circuit for High Energy Muon Trigger in PHENIX Experiment Katsuro Nakamura One of the main goals of the PHENIX experiment at RHIC is the understanding of the sea-quark polarization in a proton. Measuring the asymmetry of W boson production in polarized proton-proton collision is a powerful method to study the sea-quark polarization. The W boson is identified by the detection of a high energy muon from the decay. To acquire the data of high energy muons efficiently, an upgraded-trigger system which discriminates the high energy muons from large amount of low energy muons from hadron decays is required. One of the challenging points in this trigger system is that hit data from up to 9,500 strips of cathode-strip chambers are to be transmitted to a level-1 trigger circuit. Therefore, development of a digital circuit (MuTRG-MRG) which merges these hit data into a few data lines is necessary. In addition to the MuTRG-MRG, another digital circuit (MuTRG-DCMIF) which transmits the data to recording system is also needed for the study of the trigger performance. These two boards have been developed in KEK, installed in the PHENIX DAQ. Installed boards have been confirmed their communications with the level-1 trigger circuit and data recording module. In this presentation, the development and performance of the MuTRG-MRG board and the MuTRG-DCMIF board will be reported. [Preview Abstract] |
Thursday, October 15, 2009 10:30AM - 10:45AM |
CL.00007: Development and Performance Evaluation of Front-end Electronics for Forward W Trigger at RHIC-PHENIX experiment Yoshinori Fukao RHIC performed the first polarized proton-proton physics run with $\sqrt{s} = 500$~GeV in 2009. One of the challenging goals in 500~GeV run is to probe flavor-sorted sea quark contribution to the proton spin through the measurements of spin asymmetry in W boson production. High momentum muons from W's are detected by forward muon arms in PHENIX. Two major upgrades for the muon arm are in progress, Resistive Plate Counters (RPC) and Muon-Tracking-Chamber Front-end-Electronics Upgrade (MuTRG-FEE), to provide a trigger for the W detection. RPC features good timing and spacial resolution. MuTRG-FEE extracts fast signal of Muon Tracking Chamber. Combination of these detectors realizes the high-momentum muon trigger for W by rough online tracking. We installed MuTRG-FEE into a half of muon arm as well as the prototype of RPC in 2008. Commissioning of the new trigger was carried out with beam collisions in 2009 run. The analysis is underway to evaluate the performance of the trigger such as the efficiency and the rejection power. In this talk, I focus on the result of the MuTRG-FEE analysis and will discuss the observed performance from the data in 2009. [Preview Abstract] |
Thursday, October 15, 2009 10:45AM - 11:00AM |
CL.00008: The GlueX Central Drift Chamber Yves Van Haarlem The GlueX Central Drift Chamber (CDC) is a cylindric detector located close to a liquid hydrogen cell as a part of the GlueX spectrometer in Hall-D at Jefferson Lab. It is designed to track charged particles originating from a 12~$GeV$ polarized photon beam impinging on a liquid hydrogen target. One of the main goals of the GlueX experiment is to map out the hybrid meson spectra. The CDC has to be able to track charged particles with relative large polar angles (6-165$^{\circ}$) in a solenoid magnetic field of 2.24~$T$. Also, this detector has to perform particle identification: to separate pions from protons in a momentum range up to 450~$MeV/c$. To fulfill these tasks the GlueX collaboration opted for a straw tube chamber because this option minimizes the material in the tracking region. The straw tubes will be 1.5~$m$ long and the chamber will consist of 28 layers (12 axial + 16 stereo) or 3500 straws. The current status of this detector and test results obtained with prototypes will be presented. [Preview Abstract] |
Thursday, October 15, 2009 11:00AM - 11:15AM |
CL.00009: The GEM Tracking Subsystem for Qweak Tamuna Didberidze, Tony Forest A tracking subsystem for the Qweak experiment at Jefferson Lab has been constructed using gas electron multipliers (GEMs) to enable the detection of elastically scattered electrons at high rates. Unlike other similar tracking devices, the GEM based tracking system uses a polar coordinate system and custom designed digitization cards for readout. The coordinate system was chosen to simplify a measurement of the elastically scattered electron's squared momentum transfer. The readout electronics, designed at CERN, may be used by either silicon or GEM based detectors. The compact readout system has a high radiation tolerance and contains 128 readout channels per card. Each channel is sampled up to 40 MHz and is buffered to facilitate readout latencies up to 128 clock cycles. A description of the tracking system and the performance of the readout system will be presented. [Preview Abstract] |
Thursday, October 15, 2009 11:15AM - 11:30AM |
CL.00010: Simulation study of performance of active target GEM-TPC Ryohji Akimoto For studying nuclear properties using scatterings and charge-exchange reactions with light nuclei as incident beams, it is crucial to measure the cross sections at forward angles. In case of studing unstable nuclei, inverse kinematics is often used, but it is very difficult to measure precisely enough the forwardly emitted projectile nuclei, in particular, at medium to high energies. Alternative way is to measure the recoiled light target nuclei, and gaseous active target should be a solution which enable us to measure recoil light nuclei down to very low energy with enough resolution. Conceptual design and current status of an active target TPC with GEM for the RIKEN RIBF experiments will be presented. By using GEM, TPC can be operated at high injection rate. In the case of high intensity and medium heavy nuclear beam with intermediate energy, a large number of ion create at beam area. To lessen the effect of them, GEM don't cover the beam area. Furthermore, we evaluate the effect of the ion created when the beam passes. We set the goal of spec to 1 degree of angler resolution by FWHM for the particle flying 100mm. The result of simulation study will be shown at my talk. [Preview Abstract] |
Thursday, October 15, 2009 11:30AM - 11:45AM |
CL.00011: A tight-alignment method of emulsion position using beam tracks to study double hypernuclei Yoshiaki Nakanishi In the KEK E373 experiment, there occurred misalignment of emulsion plates. This ratio was about 3\% for tracking of $10^4$ $\Xi^-$ hyperon candidate. Since number of double hypernuclear event is at most $10^2$ for $10^5$ $\Xi^-$ hyperon tracks in the E07 experiment at J-PARC, it is quite important to develop a tight-alignment method. The method needs local calibration of emulsion positions. Therefore, we check pattern of the large amount of beam tracks which penetrate vertically emulsion plate. To do so, beam tracks should be detected at first with use of image-processing technique by taking pictures of the emulsion moving focal plane under the microscope. First step of processing is binarizing the emulsion images by applying a threshold value. Second step is summing up the all binary images and binarizing the summed image by another threshold. Thus, there are two threshold variables. We change the values of the two and check the success ratio of beam detection. Then we got the optimum values and found about 5 tracks in one position(view size:$4000{\mu}m^2$). These beam tracks are detected in another plate, it is expected that position alignment between two emulsion plates shall be carried out with 1 $\mu$m accuracy. [Preview Abstract] |
Thursday, October 15, 2009 11:45AM - 12:00PM |
CL.00012: Minimal Pixilated Resistive Plate Chamber Edwin Norbeck, Yasar Onel Two conducting plates, separated by a suitable gas at atmospheric pressure, can be used as a detector for minimum ionizing particles. However, if a spark develops the energy carried by the spark can damage the surface of the plates. The energy available to a spark can be reduced to a harmless level by covering one of the plates with a material with a high resistance. This insulating layer must be thick enough so that transient voltages do not punch holes in the layer (0.2-0.5 mm). The resistance between the front and the back of the layer needs to be large but still small enough so that the surface charge can be replenished in a time of the order of one microsecond. This requires a resistance of the order of 500 M$\Omega $/cm$^{2}$, which is in the range of ceramic enamels that are made for application to metal surfaces. The other plate can be divided into pixels, in effect making a number of separate detectors. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700