121689379
A prototype of strip readout MRPC for CBM-TOF
Abstract The time-of-flight (TOF) system of the CBM experiment is proposed to be assembled of Multi-gap Resistive Plate Chambers (MRPCs). A strip MRPC prototype with low-resistive silicate glass electrodes (bulk resistivity ∼10 10  Ω cm) was developed suited for the high rate (up to 20 kHz/cm 2 ) applications of CBM-TOF. Beam tests performed at GSI indicate time resolutions of about 70 ps with efficiencies larger than 95%. The beam position scan shows a crosstalk less than 25%.
121580460
A prototype of a high rating MRPC
Six-gap resistive plate chamber (MRPC) prototypes with semiconductive glass electrodes (bulk resistivity ~ 1010 Ωcm) were studied for suitability in time-of-flight (TOF) applications at high rates. These studies were performed using a continuous electron beam of 800 MeV at IHEP and an X-ray machine. Time resolutions of about 100 ps and efficiencies larger than 90% were obtained for flux densities up to 28 kHz/cm2.
6716887
Three-particle coincidence of the long range pseudorapidity correlation in high energy nucleus-nucleus collisions.
We report the first three-particle coincidence measurement in pseudorapidity (Δη) between a high transverse momentum (p⊥) trigger particle and two lower p⊥ associated particles within azimuth |Δϕ|<0.7 in square root of s(NN)=200 GeV d+Au and Au+Au collisions. Charge ordering properties are exploited to separate the jetlike component and the ridge (long range Δη correlation). The results indicate that the correlation of ridge particles are uniform not only with respect to the trigger particle but also between themselves event by event in our measured Δη. In addition, the production of the ridge appears to be uncorrelated to the presence of the narrow jetlike component.
122051470
Performance of a new LMRPC prototype for the STAR MTD system
A new prototype of a Long-Strip Multi-Gap Resistive Plate Chamber (LMRPC) for the STAR Muon Telescope Detector (MTD) at RHIC has been developed. This prototype has an active area of 52 x 90 cm(2) and consists of six 250 mu m wide gaps. Each detector has 12 strips, read-out at both ends, which are each 3.8 cm wide and 90 cm long with 0.6 cm intervals. In cosmic-ray tests, the efficiency was larger than 95% and the time resolution was similar to 75 ps for the 94% Freon, 5% iso-butane, and 1% SF6 gas mixture. There was good uniformity in the performance across the different strips. The module was also tested in a proton beam at IHEP in Beijing. The efficiency was close to 100% and the best timing resolution achieved was 55 ps for the 90% Freon, 5% iso-butane, and 5% SF6 gas mixture. Trigger scans along and across the strip direction were also performed. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.
56430796
Measurements of $D^{0}$ and $D^{*}$ Production in $p$ + $p$ Collisions at $\sqrt{s}$ = 200 GeV
We report measurements of charmed-hadron ($D^{0}$, $D^{*}$) production cross sections at mid-rapidity in $p$ + $p$ collisions at a center-of-mass energy of 200 GeV by the STAR experiment. Charmed hadrons were reconstructed via the hadronic decays $D^{0}\rightarrow K^{-}\pi^{+}$, $D^{*+}\rightarrow D^{0}\pi^{+}\rightarrow K^{-}\pi^{+}\pi^{+}$ and their charge conjugates, covering the $p_T$ range of 0.6$-$2.0 GeV/$c$ and 2.0$-$6.0 GeV/$c$ for $D^{0}$ and $D^{*+}$, respectively. From this analysis, the charm-pair production cross section at mid-rapidity is $d\sigma/dy|_{y=0}^{c\bar{c}}$ = 170 $\pm$ 45 (stat.) $^{+38}_{-59}$ (sys.) $\mu$b. The extracted charm-pair cross section is compared to perturbative QCD calculations. The transverse momentum differential cross section is found to be consistent with the upper bound of a Fixed-Order Next-to-Leading Logarithm calculation.
120854659
Study on the position resolution of resistive plate chamber
A prototype RPC detector with a 2-mm readout strip pitch has been built for research into its position resolution. After determining the optimal threshold and working voltage, the efficiency and position resolution of this prototype RPC detector have been studied carefully. Using cosmic-ray muons with different directions and incident positions, we have obtained less than 0.5-mm average statistical errors of position resolution for two different RPC readout structures: 1- and 1.7-mm readout strip widths. The results show that the RPC can also give high position resolution with very little variation from its traditional structure. This will lead to possible applications of the RPC in medical imaging and other domains.
123544625
A new design of large area MCP-PMT for the next generation neutrino experiment
This manuscript discusses a new design of large area MCP-PMT for the next generation neutrino experiments. The main motivation of the design is to improve the quantum efficiency (photo detection efficiency) of the PMT. Two sets of small MCP units, the transmission photocathode coated on the front hemisphere and the reflection photocathode coated on the rear hemisphere are assembled in the same glass envelope to form nearly 4 pi viewing angle to enhance the efficiency of the photoelectron detection. The photoelectrons from the 4 pi photocathode are collected and amplified by two sets of MCP units. Our goal is eventually to produce 20 in. diameter PMT following such an approach. We will report preliminary results of our ptoelectronic simulation and the results of a 5 in. diameter prototype PMT. Future plans and prospects are discussed at the end. (C) 2011 Elsevier B.V. All rights reserved.
121107871
Electron-pion discrimination with a scintillating fiber calorimeter
Abstract We report on an experimental study of a variety of techniques for discriminating between (isolated) electrons and pions in a lead and scintillating fiber calorimeter without longitudinal segmentation. Using information from the lateral shower development, from a pre-shower detector, from the time structure of the signals, or from a combination of these we measure pion rejection factors of up to several thousand while maintaining electron efficiencies of 95% or higher.
122914096
The design and mass production on resistive plate chambers for the BESIII experiment
A new type of the phenolic paper laminate is used as the resistive electrodes of BESIII RPC. The surface smoothness of these laminates is comparable to that of the bakelite plates with linseed oil treating. A technique to adjust the bulk resistivity of the laminates within the range of 10 9 –10 13 O cm is developed. Nowadays, about 1000 bare chambers (1200 m 2 ) have been produced and used for BESIII MUON, and the rejection rate is only 1.5%. In this paper, we will discuss the mass production and quality control procedures of these RPCs. r 2007 Elsevier B.V. All rights reserved. PACS: 29.40.n; 29.30.Cs
119797946
Application of silicon-detector technology to experiments in space. An option for the Astromag facility
SummaryCosmic antimatter search needs transportation systems of the apparatus outside the atmosphere. The Astromag facility on the NASA space station will be a great opportunity for such a search in the next future. Here we discuss the advantages achievable from silicon-detector technology in space research and we propose a silicon calorimeter as an ideal option to work in connection with the Astromag facility itself.RiassuntoLa ricerca di antimateria cosmica necessita di sistemi di trasporto e di apparati al di fuori dell’atmosfera. La facility Astromag, posta sulla stazione spaziale della NASA, costituirà nel prossimo futuro una grande opportunità per questo tipo di ricerca. Si discutono qui i vantaggi che si possono ottenera dalla tecnologia dei rivelatori a silicio nella ricerca spaziale e si propone un calorimetro a silicio come opzione ideale per operare in connessione con la facility Astromag stessa.РезюмеПоиски антивещества в космосе требуют транспортных систем для вывода экспериментальной аппаратуры за пределы атмосферы. Экспериментальная установка «АСТРОМАГ» на космической станции NASA представляет болышие возможности для таких поисков. Мы обсуждаем преимущества технологии кремниевых детекторов в космических исследованиях. Предлагается кремниевый калориметр, как идеальный прибор для установки «АСТРОМАГ».
108707403
The high timing resolution T0 system in IHEP E3 beam line
The designed aim of the multi-gap resistive plate chamber module (MRPC) for the BESIII endcap TOF upgrade project is less than 50 ps, so a Time-zero (T0) system is required to achieve the timing resolution at 30 ps level. After study the scintillator, the PMT, the DAQ subsystem, the assemblage form and the distributing position, the timing resolution of this type of T0 detector composed of scintillator BC420 coupling with PMT H6533 could achieve 30 ps level. Further more, the T0 could also perform the particle identification (proton and pion) just as the beam TOF and EMC detectors during the beam test process for the compelling result. For this type of T0 system, the MRPC beam test was finished and achieved a compelling result.