Performance testing of a long-strip two-end readout multi-gap resistive plate chamber

Multi-gap Resistive Plate Chamber (MRPC) is a new generation of gas detector with good tim-ing and spacial resolution, whose technique is widely applied in some recent high energy (nuclear) physics experiments. In this letter, we report a long-strip two-end readout MRPC and its test beam performance. The measurements show that the long-strip performs a transmission line characteristic and the impedance is independent of the length of strip. The MRPC module we developed is presented to gain a timing resolution of～80 ps and a spacial resolution of ～6.4 mm. The possible application of the MRPC is also discussed.     

多气隙电阻板室飞行时间谱仪技术

基于多气隙电阻板室(MRPC)技术的飞行时间谱仪广泛应用于现代物理实验,并在粒子鉴别中发挥了重要作用.随着加速器能量和实验亮度的提高,对飞行时间谱仪的粒子计数率和时间分辨要求越来越高.MRPC飞行时间谱仪按技术上可以分成三代.从第一代到第三代,计数率要求越来越高( 30 kHz/cm~2),时间精度也更加严格(20 ps),相应的探测器结构和读出电子学系统呈现出不同的特性.本文总结了三代飞行时间谱仪技术的主要技术特点及主要物理实验,介绍了已经取得的应用成果,提出了该技术的未来发展方向.同时也介绍了MRPC探测器在工业及医学方面的应用.     

Study of a multi-wire proportional chamber with a cathode strip and delay-line readout

The design principle for a multi-wire proportional chamber with a cathode strip and delay-line readout is described. A prototype chamber of a size of 10 cm×10 cm was made together with the readout electronics circuit. A very clean signal with very low background noise was obtained by applying a transformer between the delay-line and the pre-amplifier in order to match the resistance. Along the anode wire direction a position resolution of less than 0.5 mm was achieved with a ^55Fe-5.9 keV X ray source. The simple structure, large effective area and high position resolution allow the application of a gas chamber of this kind to many purposes.     

GEANT4 simulation of gamma ray in a double-gap resistive plate chamber

For more than 20 years nuclear physicists have used the GEANT code to simulate particle-matter interaction. In most recent version, GEANT4 is a toolkit for simulating the passage of particles though matter, which contains a complete range of functionality including tracking, geometry, physics models, and hits. In this article, an attempt to use GEANT4 to model a double-gap resistive plate chamber （RPC） with its improved efficiency is presented. The efficiencies of the double-gap RPC have been evaluated as a function of gamma energy range 0.005-1000MeV. A comparison to available previous simulation package GEANT3 data is also performed.     

多气隙电阻板室的时间特性研究

一种具有10个气隙的多气隙电阻板室,在欧洲核子研究中心实验束上进行了性能测试.该探测器采用几何上串联和电极上并联的特殊结构,使用国产玻璃(厚度1?.1mm)作为高压电极,有效灵敏面积为200mm×63mm²,并具有2×6读出条.对7GeV/c的π^－粒子,其探测效率大于99%,时间分辨达到45ps.     

高时间分辨MRPC的位置灵敏读出方法

根据MRPC工作机制和高时间分辨的特性, 研制一种位置灵敏MRPC原型及读出方法. 该探测器具有10个220μm气隙, 有效探测面积为20cm×20cm. 前端电子学采用专用ASIC芯片, 具有快时间响应和输入电荷-输出信号宽度的转换功能. 采取同时读取信号传输时间差和感应信号分布的方法实现两维读出. 对该探测器性能的束流测试结果显示: 沿着读出条方向及其垂直方向的位置分辨分别为4.5mm和1.6mm, 其时间分辨达到63ps, 探测效率>95%.     

A prototype of a high rating MRPC

Six-gap resistive plate chamber (MRPC) prototypes with semiconductive glass electrodes (bulk resistivity～1010.cm) 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.     

一个高时间分辨的多间隙电阻板室原型

研制了一种多气隙电阻板室原型并建立了相关的测试系统.利用宇宙线测试系统和欧洲核子中心的试验束装置T1?0对其性能进行了测试,给出了初步结果.时间分辨达到70ps,对最小电离粒子的探测效率大于95%.     

基于阻性阳极读出方法的气体电子倍增器二维成像性能

新型微结构气体探测器,如气体电子倍增器(gas electron multiplier,GEM)等,具有非常好的位置分辨率潜力(σ100μm),但是需要匹配大规模高密度的读出电子学,给探测器的建设、造价、功耗、空间利用等带来极大压力.阻性阳极读出方法可以在保持较高位置分辨率的前提下,大幅节省电子学.基于厚膜电阻工艺,一种新的阻性单元阵列结构被成功开发和应用于三级级联GEM探测器的读出阳极.该阻性阳极包括6×6个6 mm×6 mm的基本阻性单元,仅需匹配49路读出电子学.~(55)Fe放射源(5.9 keV)和X光机(8 keV)实验的结果显示探测器的位置分辨率(σ)可好于80μm,位置非线性好于1.5%.同时,探测器还获得了很好的实物成像效果.探测器的优良性能表明这种阻性阳极读出方法适用于大面积二维成像气体探测器的读出,并可用于其他探测器的读出.     

A prototype of a high rating MRPC

Six-gap resistive plate chamber （MRPC） prototypes with semiconductive glass electrodes （bulk resistivity ～ 10^10Ω·cm） 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/cm^2.     

Simulation study using GEANT4 Monte Carlo code for a Gd-coated resistive plate chamber as a thermal neutron detector

The Resistive Plate Chamber (RPC) has been developed in many application areas ever since its introduction, from high energy physics experiments to positron emission tomography. Such detectors can be coated with a Gd layer that enables them to detect thermal neutrons. Consequently these RPCs can be utilized for industrial and medical purposes. Here, we present the configuration of a resistive plate chamber which is utilized to detect thermal neutrons by employing GEANT4 Monte Carlo code. The response of the RPC was evaluated as a function of neutron energy in the GEANT4 Monte Carlo code. The simulation results are taken for incident neutron energy in the energy range from 25 meV to 100 meV. The detection efficiency was found to be between 10% and 20%, depending on the detector configuration, for incident thermal neutrons of 25 meV energy.     

Delay line readout of a large dimension multi-wire proportional chamber

A two dimensional multi-wire proportional chamber with delay line readout was developed, which has a large sensitive area of 30 cm× 30 cm. Two cathode planes using printed circuit boards are orthogonally placed to give two coordinates of the impact point of the particle. Signals collected from the cathode strips are amplified and discriminated from two ends of the delay line at each cathode board. By recording the time difference between the two discrimination pulses and the common gate pulse from anode wires, a coordinate position was reconstructed, and a position resolution of better than 1 mm could be obtained in the whole sensitive area along the anode wires.     

Performance test of the low-pressure thin window multi-wire chamber

A flow gas low-pressure multi-wire proportional chamber(LPMWPC)with an active area of 180 mm×80 mm has been developed for the flying time test of the recoil nuclei on super heavy nuclear experiments.The LPMWPC detector can be operated in single as well as double step operational modes.In the case of double step operational mode with a high gas amplification factor,signals fromα-particles reside well above the electronic noise.The gas leakage rate and time resolution obtained from theα239Pu source are shown and discussed at the condition of 3 mbar Isobutane gas.It was shown that the time resolution was better than 2.9 ns at the best work condition,and the detecting efciency was larger than 98%at the low energyαparticles.So the LPMWPC is fit to measure the flying time in the super heavy nuclear fragments experiment.     

Performance study of new style mosaic MRPC

The Compact Muon Solenoid (CMS) at LHC intends to use a high rate trapezoid MRPC for the muon system upgrade, but the size of the MRPC is limited by the dimensions of low resistivity glass. We have designed a prototype of a large MRPC in which the electrodes are developed by gluing two pieces of glass plates. Simulation of the weighting field and cosmic ray test shows that the efficiency of the glued MRPC is higher than 96% and the time resolution is better than 71 ps.     

MRPC宇宙线批量测试方法探讨

通过分析33个多气隙电阻板室(MRPC)的宇宙线测试结果, 得到了雪崩信号比例和 平均幅度与时间分辨的关系, 计算得出了MRPC的分辨时间随测试事例数的变化 趋势. 据此提出了~MRPC~的宇宙线批量测试方法.     

Study of a multi-wire proportional chamber with a cathode strip and delay-line readout

The design principle for a multi-wire proportional chamber with a cathode strip and delay-line readout is described. A prototype chamber of a size of 10 cm ～ l0 cm was made together with the readout electronics circuit. A very clean signal with very low background noise was obtained by applying a transformer between the delay-line and the pre-amplifier in order to match the resistance. Along the anode wire direction a position resolution of less than 0.5 mm was achieved with a 55Fe-5.9 keV X ray source. The simple structure, large effective area and high position resolution allow the application of a gas chamber of this kind to many purposes.     

MRPC宇宙线测试及温度效应

建造了一套MRPC单元的宇宙线测试系统.在数据处理过程中实现对入射宇宙线的方向选择.实验结果表明:MRPC的时间分辨可以达到约84ps,对应的触发系统参考时间分辨可以达到约75ps.对MRPC的温度特性进行了研究,得到了一些初步结论.     

Background neutron in the endcap and barrel regions of resistive plate chamber for compact muon solenoid/large hadron collider using GEANT4

In this study the performance of double gap RPC has been tested by GEANT4 Monte Carlo simulation code. The detector response calculations taken as a function of the neutron energy in the range of 0.01 eV-1 GeV have been simulated through RPC set-up. In order to evaluate the response of detector in the LHC background environment, the neutron spectrum expected in the CMS muon endcap and barrel region were taken into account. A hit rate of about 165.5 Hz cm⁻², 34 Hz cm⁻², 33.6 Hz cm⁻², and 27.0 Hz cm⁻² due to an isotropic neutron source is calculated using GEANT4 standard electromagnetic package for a 20 × 20 cm² RPC in the ME1, ME2, ME3 and ME4, respectively. While for the same neutron source and using GEANT4 package a hit rate of about 0.42 Hz cm⁻², 0.7182 Hz cm⁻² was measured for the MB1 and MB4 stations respectively. Similar characteristics of hit rates have been observed for GEANT4 low electromagnetic package.      

高增益型气体电子倍增微网结构探测器的性能研究

随着微结构气体探测器的不断发展, 不同的探测需求相继提出.为了实现气体探测器在高增益和低打火率的条件下长时间稳定工作, 结合气体电子倍增器(GEM)与微网结构气体探测器(MicroMegas)的探测优势, 成功研制出一种基于GEM作为预放大的MicroMegas探测器, 详细介绍了探测器结构和工作原理, 并利用⁵⁵Fe放射源对探测器增益、打火率、能量分辨和工作稳定性等性能进行了实验测量. 分析结果显示GEM-MicroMegas探测器可以连续工作30 h 以上, 探测器增益可以超过10⁶, 相对于无GEM膜的MicroMegas探测器, 相同增益下打火率可以降低近100倍. 关键词： 微网结构气体探测器 能量分辨率 增益 打火率     

大面积玻璃RPC模型与性能测试

介绍了可用于粒子探测的大面积玻璃高阻板探测器RPC(Resistive Plate Chamber).使用两块间隔2mm的普通浮法玻璃作为电极,其中充入流动的混合气体(氩气+异丁烷+F134A),工作高压约9600V;性能测试结果,其单室效率可达97%,时间分辨可达到1.8ns.