束流模拟装置的阻抗对标定结果的影响

对偏心束流在束流管道中产生的电磁场和束流模拟装置的偏心同轴线中的电磁场进行了理论分析。分析表明,在束流模拟装置阻抗较小时,二者存在显著差异。该差异对束流流强探测器、束流位置探测器和束流偏角探测器的标定有一定的影响。如果采用阻抗为50Ω的束流模拟装置标定束流位置探测器,得到的等效管道半径将比真实值偏小19%。利用理论分析结果,合理地解释了一个B-dot束流位置探测器的标定结果。     

宇宙线探测系统的建立及阻抗板探测器的测试

在实验室内建立了一套宇宙线测试系统(CORTS)，并对一个大面积CMS RE1/2 RPC的完整样品进行了系统的测试. 结果为RPC的探测效率约85%，时间分辨率为0.87±0.08ns，空间分辨本领为1.5根读出条宽度，与CERN束流测试中得到的数据基本吻合. 对比表明采用宇宙线测试可以可靠地获得若干关键的RPC探测器性能指标.     

上海光源储存环横向反馈系统模拟计算

在同步辐射光源中, 阻抗壁不稳定性是一个很严重的问题. 要保证储存环在高流强下正常运行, 就需要安装一套横向反馈系统. 为了了解在横向反馈作用下束流的动力学性质,建立了一套横向反馈模拟计算程序. 并用该程序模拟计算了上海光源储存环横向反馈系统在闭轨误差(COD)、束流位置探测器读数误差以及梳状滤波等条件改变下的反馈效果.     

CSNS多功能反射谱仪主探测器读出电子学系统研制

为满足中国散裂中子源（CSNS）多功能反射谱仪（MR）主探测器高气压3He多丝正比室探测器（MWPC）的需求,研制了专用的读出电子学系统。该系统主要由核心前放板和触发扇出板构成,其中以前放板为核心,采用了6块前放板实现探测器142路模拟信号的数字化,并通过判选机制甄别中子信息,将有效中子事例打包发送给后端,触发扇出板提供同一时刻到达的T0信号和触发信号,以确保数据的对齐。读出电子学系统分别在实验室和束流条件下,进行了相关指标测试,测试结果表明性能优于设计要求。目前MWPC探测器已经成功安装到MR谱仪现场,并且已经开始稳定运行。     

重离子治癌加速器束诊探测器运动控制系统设计

重离子医疗装置（HIMM）中需要束流诊断探测器来测量加速器束流参数,其中大部分探测器属于拦截式探测器,拦截式探测器在测量束流参数时需要将探测器探头插入束流管道中心,测试完成后将探测器拉出。另外,部分探测器需要联动控制,针对上述需求,设计了基于EtherCAT协议的拦截式探测器的运动控制系统架构,并且开发了基于OPC UA （OLE for Process Control Unified Architecture）协议的客户端/服务器软件系统,所有拦截式探测器已通过CFDA （China Food and Drug Administration）验证,自2017年起在束运行至今。使用结果表明,该系统具有较高的稳定性以及可移植性,控制精度以及控制模式均可完全满足现场应用要求。     

PPAC在单粒子效应地面模拟实验中对束流均匀度测量的应用

单粒子效应(SEE)加速器地面模拟需要离子束具有较好的均匀度,针对回旋加速器单粒子效应模拟的束流特点,建立了一套以位置灵敏平行板雪崩探测器(Parallel Plate Avalanche Counter,PPAC)为基础的均匀度探测系统并完成了带束测试,对它的结构、工作原理、均匀度获得方法及带束测试结果进行描述。为验证PPAC测量结果准确性,在带束测试过程中,前方同时放置PET膜测量穿过PPAC探测器的粒子分布,与离子径迹测量结果对比,给出PPAC的均匀度的测量误差在5%之内。探测器具有50 mm×50 mm的灵敏面积和小于1 mm的位置分辨,符合单粒子效应实验对束流均匀度测量的要求。     

在大型强子对撞机上的CMS实验

LHC(large hadron collider)是目前世界上能量最高的强子对撞机.CMS(compact muon solenoid,中文译名是紧凑型缪子螺线管探测器)是LHC上的主要实验计划之一,其目标就是要寻找Higgs粒子或者超出标准模型的其他新粒子,探清自然界的电弱破缺机制,以及寻找暗物质.CMS实验位于高能量和高亮度的最前沿,是21世纪初人类认识微观世界最重要的物理实验之一.中国参加了这项国际合作,制作了部分μ子探测器、磁铁支架、电子学和地板等,目前转入物理研究工作,争取在物理研究中作出有显示度的贡献.文章简要介绍了CMS探测器以及CMS实验的目标和意义.     

大型强子对撞机上的CMS探测器

CMS探测器是大型强子对撞机(LHC)上的4个实验之一,它的设计思想是在质心能量为14TeV及积分亮度为1034cm-2s-1的条件下对质子-质子对撞进行研究.它的特点是非常紧凑,其μ子室几乎覆盖了4π立体角.另外,CMS探测器还有可提供超强磁场的超导磁铁和由超导磁铁环绕的径迹室以及电磁量能器和强子量能器.CMS探测器对于末态为电子、光子、特别是μ子的物理过程有很好的测量精度.     

RIBLL束流诊断的发展

描述了重离子加速器放射性次级束流线束流诊断技术的新发展,它包括初级束流在线监测研制的非拦截式法拉第筒,监测低强度初级束流的塑料闪烁探测器,测量放射性次级束流剖面的大面积双维位置灵敏平行板雪崩室等.这些新研制的束流诊断装置的运用,明显提高了设置、调整、确定重离子加速器放射性次级束流线运行参数的速度和准确性,改善了放射性次级束流纯度和质量,并使得重离子加速器放射性次级束流线的运行更简洁、迅速和有效.     

强流直线感应加速腔微波特性

 介绍了确定不同加速间隙形状和设计结构的强流直线感应加速腔微波特性的方法,即确定频域中加速腔横向阻抗值的方法,包括数值模拟和实验测试。 横向阻抗测试实验中采用了两种测试方法:一种为同轴线束流模拟法,另一种为对加速腔形状因子的测试。实验中测试了3种不同的腔型,并和数值模拟结果进行了比较。两种横向阻抗的测试方法所得结果都与计算结果基本符合,从测试过程的繁简程度和多次实验结果的重复性来看,对于强流直线感应加速腔来说,形状因子值测试方法优于双芯同轴线束流模拟法。实验测试和数值模拟结果显示,确定直线感应加速腔横向阻抗值,测试实验和数值模拟是相辅相成的,缺一不可。     

Beam Test Results of the First Full-Scale Prototype of CMS RE1/2 Resistive Plate Chamber

We reported the muon beam test results of the first full–scale prototype of CMS RE1/2 Resistive Plate Chamber (RPC).The bakelite surface is treated using a special technology without oil to make it smooth enough.The full scale RE1/2 RPC with honeycomb supporting frame is strong and thin enough to be fitted to the limited space of CMS design for the inner forward RPC.The muon beam test was performed at CERN Gamma Irradiation Facility (GIF).The detection efficiency of this full scale RPC prototype is>95% even at very high irradiation background.the time resolution (less than 1.2 ns) and spatial resolution are satisfactory for the muon trigger device in future CMS experiments.The noise rate is also calculated and discussed.     

Study of the anode self-trigger ability of the ME1/1 CMS Endcap Cathode Strip Chamber

The influence of the high background rates on the Cathode Strip Chamber (CSC) anode trigger ability has been studied. The investigation has been made with a P3 prototype of the CSC of ME1/1 Endcap muon station of the CMS experiment (CERN). The work has been done at the Gamma Irradiation Facility (GIF, CERN). P3 has been installed at the SPS X5c muon beam line in a background field of ¹³⁷Cs source. The CSC timing resolution and the track registration efficiency as a function of gamma rate are presented. The text was submitted by the authors in English.     

Electromagnetic secondaries and punch-through effects in the CMS ME1/1

The aim of this work is to estimate the shower leakage from the CMS Endcap Hadron calorimeter (HE) due to electromagnetic secondaries and punch-through in the region of the ME1/1 Forward Muon Station. Two configurations are considered: with and without the CMS Endcap Electromagnetic calorimeter (EE). The experimental data have been taken during the combined beam test of CMS subdetectors (HE, ME, RPC, DT) at the CERN H2 beam facility in 2004. Serial CSC chambers (ready for installation in CMS) fully equipped with readout electronics have been exposed. Simulation of a beam test setup has been performed using the GEANT4-based simulation software package OSCAR. The text was submitted by the authors in English.     

Data-driven performance evaluation method for CMS RPC trigger system using 2011 data at LHC

The compact muon solenoid (CMS) is one of the four experiments which is getting and analysing the results of the collision of protons at LHC. The CMS trigger system is divided into two stages, the level-1 trigger and high-level triggers, to handle the large stream of data produced in collision. The information transmitted from the three muon subsystems (DT, CSC and RPC) are collected by the Global Muon Trigger (GMT) Board and merged. A method for evaluating the RPC system trigger efficiency with data from pp collision was developed using the features of GMT. The results of the study with the real data of 2011 are shown and discussed here along with the comparison of Monte Carlo results.     

The spatial resolution of the CMS ME1/1 muon station cathode strip chambers with CRAFT08 data

The spatial resolution of the outer part of the ME1/1 muon station has been studied with CRAFT08 (Cosmic Rays At Four Tesla-2008) data at the CMS detector (CERN). The ME1/1 Cathode Strip Chamber (CSC) layer spatial resolution as a function of the CMS solenoid magnetic field is presented. The influence of the strip width and anode wire tilt on the spatial resolution has been studied. Finally, the spatial resolution for the ME1/1 6-layer CSC was calculated and the ME1/1 outer part spatial resolution was estimated.     

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.     

Design, performance, and calibration of?the?CMS?hadron-outer?calorimeter

The Outer Hadron Calorimeter (HCAL HO) of the CMS detector is designed to measure the energy that is not contained by the barrel (HCAL HB) and electromagnetic (ECAL EB) calorimeters. Due to space limitation the barrel calorimeters do not contain completely the hadronic shower and an outer calorimeter (HO) was designed, constructed and inserted in the muon system of CMS to measure the energy leakage. Testing and calibration of the HO was carried out in a 300 GeV/c test beam that improved the linearity and resolution. HO will provide a net improvement in missing E _T measurements at LHC energies. Information from HO will also be used for the muon trigger in CMS. Deceased. Now at University of Pennsylvania, Philadelphia, PA, USA. At Niğde University, Niğde, Turkey. At Marmara University, Istanbul, Turkey. At Kafkas University, Kars, Turkey. At Süleyman Demirel University, Isparta, Turkey. At Mersin University, Mersin, Turkey. At Izmir Yüksek Teknoloji Enstitüsü, Izmir, Turkey.     

A fast muon trigger for the PHENIX forward spectrometer upgrade

The PHENIX forward upgrade adds nosecone calorimeters and level-1 trigger (LVL-1) detectors to the muon forward spectrometers. The muon detector will trigger on high pT muons from W decay and reject background. This will enable study of quark and anti-quark polarizations in the proton. The upgrade will add momentum and timing information to the present muon trigger. Signals from 3 Resistive Plate Chambers (RPCs) will provide momentum and timing information for the LVL-1 trigger. Each RPC carries a plane with coarse structure to establish a space point for timing and one with radial cathode strips for azimuthal resolution. Timing resolution of ≈ 2 ns rejects beam-related backgrounds and tracking from RPCs minimizes muons from hadron decays. RPC information is sent by optical. bers to LVL-1 trigger processors. A discussion of physics measurements possible, layout of the upgrade and details of RPC design and tests are given below. for the PHENIX collaboration Presented in the Poster Session “Future Experiments and Facilities” at the 18th International Conference “Quark Matter 2005”, Budapest, Hungary, 4–9 August 2005.     

Design, performance, and calibration of CMS hadron-barrel calorimeter wedges

Extensive measurements have been made with pions, electrons and muons on four production wedges of the compact muon solenoid (CMS) hadron barrel (HB) calorimeter in the H2 beam line at CERN with particle momenta varying from 20 to 300 GeV/c. The time structure of the events was measured with the full chain of preproduction front-end electronics running at 34 MHz. Moving-wire radioactive source data were also collected for all scintillator layers in the HB. The energy dependent time slewing effect was measured and tuned for optimal performance.     

Plastic scintillator-based hodoscope for the characterization of large-area resistive plate chambers

A scintillator-based hodoscope is fully operational at Nuclear Physics Division, Bhabha Atomic Research Centre (NPD-BARC). It was used for characterizing the resistive plate chambers (RPCs) assembled for the RE4 upgrade for the compact muon solenoid (CMS) experiment, installed during the long shut-down (LS1) using cosmic muons. It has now been employed for R & D related to gas mixtures and glass RPCs for the India-based neutrino observatory (INO) and muon tomography studies. The hodoscope is equipped with gas flow lines, LV, HV and VME-based DAQ with multihit TDCs. CERN-based software was adapted, implemented and along with the cosmic trigger, was used to evaluate the functional parameters for the RPCs, such as efficiency, cluster size etc.