北京谱仪端盖簇射计数器的能量分辨及其模拟研究

利用北京谱仪J/ψ、ψ′、D_s能量下端盖簇射计数器(ESC)内的e⁺e^－末态事例,研究了电子簇射在ESC中单个计数管的脉冲幅度分布、击中单元总数分布和各读出层的击中单元数分布、沉积能量分布和总沉积能量的分布;得到能量分辨约为22%/E(GeV)在SOBER程序框架的基础上采用双高斯分布描述单计数管脉冲幅度谱,EGS4描述电磁簇射,考虑了三维磁场分布,完成了ESC蒙特卡罗模拟程序,模拟结果与实验数据符合很好.     

高能核核碰撞中反应系统的纵向扩展与横向激发

考虑到高能核核碰撞中反应系统的纵向扩展与横向激发，用热化柱图像对簇射粒子的赝快度分布和横动量分布进行了描述，计算结果与ＣＥＲＮＳＰＳＣ能区的实验数据符合。     

北京谱仪桶部簇射计数器的改进升级

描述了北京谱仪桶部簇射计数器（ＢａｎｅｌＳｈｏｗｅｒＣｏｕｎｔｅｒ）的改进升级工作,改进后的桶部簇射计数器在能量分辨和位置分辨方面有了明显的提高,经对Ｂｈａｂｈａ事例进行离线刻度后,能量分辨好于２１％,ｚ向位置分辨小于３ｃｍ．     

基于羊八井ARGO实验的原初γ射线成分分辨

利用蒙特卡罗(Monte Carlo)模拟产生的数据研究了由ARGO探测阵列所观测的，由能量为100GeV-10TeV，天顶角为0°-45°的原初γ射线和强子(质子和原子核)所引起的簇射的横向分布结构，得到了平均横向分布宽度、最小树长度等可以描述两种簇射空间分布差异的特征量. 研究了用这些特征量作为输入单元的人工神经网络分析方法进行原初γ和强子分辨的能力，结果表明，利用该方法可有效地区分γ和强子簇射.     

含MoFe3S4单元的μ2-OR或μ2-SR桥联双类立方烷簇合物的红外光谱研究

对下列含ＭｏＦｅ３Ｓ４ 单元的μ２－ＯＲ或μ２ －ＳＲ桥联双类立方烷簇合物的红外光谱进行了研究：（Ｅｔ４ Ｎ）３［Ｍｏ２Ｆｅ６ Ｓ８Ｃｌ６ （ＯＭｅ）３ ］（１）,（Ｅｔ４ Ｎ）３ ［Ｍｏ２ Ｆｅ６ Ｓ８ （ＳＰｈ）６ （ＯＭｅ）３ ］（２）,（Ｂｕ４Ｎ）３ ［Ｍｏ２Ｆｅ６Ｓ８ （ＳＰｈ）６ （ＯＭｅ）３ ］（３）,（Ｅｔ４Ｎ）３ ［Ｍｏ２Ｆｅ６Ｓ８ （ＳＢｕｔ）６（ＯＭｅ）３］（４）,（Ｅｔ４Ｎ）３ ［Ｍｏ２Ｆｅ６Ｓ８ （ＳＰｈ）９ ］（５）。通过这系列簇合物特征振动频率和结构参数及与线型Ｍｏ－Ｆｅ－Ｓ簇合物红外光谱的比较,对其νＭ ｏ－μ２Ｏ（Ｒ） ,νＭ ｏ－μ２Ｓ（Ｒ）,νＭ ｏ－Ｓ,νＦｅ－Ｓ,νＦｅ－ＳＲ,νＦｅ－Ｃｌ 进行了归属。对其中两条途径的亲电诱导效应及Δν（即νＭ ｏ－Ｓ－νＦｅ－Ｓ）与Ｆｅ→Ｍｏ 电荷迁移的关系进行了探讨。最后,讨论了桥联双类立方烷与线型Ｍｏ－Ｆｅ－Ｓ簇合物红外光谱的共性和差异。     

高功率红宝石激光脱附的铜团簇离子的速率和能量分布

用飞行时间质谱仪测量了铜阳离子团簇Ｃｕ＋的能量。团簇Ｃｕ＋ｎ（ｎ≤５）用高功率脉冲红宝石激光从铜样品上脱附。用两次质谱法测定了主铜离子团簇Ｃｕ＋的速度分布与相应的能量分布，发现它的最可几速率和最可几能量分别为１０ｋｍ／ｓ和３３ｅＶ。结果还表明，它的动能分布在一个很宽的范围内（０－１５０ｅＶ）。对离子产生机理进行的探讨表明，在激光和固体的这种相互作用时，固—气两相处在非平衡态中。     

SiGe ECL电路时间延迟分析

为保证 ＥＣＬ具有更好的电路性能,低温下制备 ＳｉＧｅ ＨＢＴ作为基本器件的 ＳｉＧｅ ＥＣＬ电路更适于低温应用,且传输延迟时间更小．１引言 ＳｉＧｅ ＥＣＬ电路是目前国际研究前言,在高速 ＣＰＵ、卫星通讯等领域有较高应用价值,在国内军事领域也将会有应用前景［１］ 采用ＳｉＤｅ ＨＢＴ作为ＥＣＬ电路单管可实现更低延迟时间单元电路［２］．为保证ＥＣＬ单元电路具有较快速度,ＳｉＤｅ ＨＢＴ需采用超薄基区、低发射区掺杂高基区掺杂等新型结构［３,４］． 从基尔霍夫方程出发,可对ＥＣＬ对管延迟时间作较为精确的推导．ｔ…     

蓝色显示材料及器件的研究

用Ｈ２和ＣＳ２还原法制备Ｃｅ：ＳｒＳ发光材料，分析了两种方法对材料的结构及发光特性的影响，得到了最高亮度为９５０ｃｄ／ｍ＾２（１０００Ｈｚ）的Ｃｅ：ＳｒＳ薄膜电致发光（ＴＦＥＬ）器件；用高温固相法得到Ｃｅ：ＳｒＧａ２Ｓ４荧光粉，用射频溅射沉积的Ｃｅ：ＳｒＧａ２Ｓ４薄膜在６００℃以上、Ｈ２Ｓ气氛下快速热处理可以改善薄膜结晶性能，提高杂质激发峰强度，得到好的光致发光（ＰＬ）发光性能，以陶瓷片作为基片同     

SinSem分子簇的SCC—DV—Xa方法的计算研究

本文应用ＳＣＣ－ＤＶ－Ｘａ方法计算了（ＲＳｉ）４Ｓｅ６，（ＲＳｉ）２Ｓｅ３和Ｒ４Ｓｉ３Ｓｅ４（Ｒ＝ＣＨ３，Ｃ２Ｈ５，Ｐｈ）等分子簇的结合能，轨道能级，电荷分布，状态密度，分析了簇的稳定性，ＮＭＲ化学位移，紫外可见吸收和催化性能等，结果与实验相符。     

BES端盖簇射计数器模型的束流测试

研制并测试了一台铅板和自猝灭流光管夹层式的气体取样簇射计数器. 计数管使用了铝方管和阳极丝读出. 能量分辨σ/E在E_e=1GeV时达15.5%, 能量响应范围是0—2GeV. 本文描述了束流测试的方法和计数器模型的各种性能.     

Energy Resolution and Its Simulation for the ESC of BES

With data collected by the Beijing Spectmmeter (BES) in the J/ψ,ψ′, and D_s energy region, a lot of e⁺e^－ final state evenb are selected in the solid angle region covered by the endcap shower counters (ESC). Some characteristics of the ESC are analysed, such as the spectrnun of pulse height for, a single counter cell, the hit nwnbers in the ESC and in every reading layer of the ESC, the shower energies deposited in the ESC and in every layer of the BSC. The energy resoiudon of the ESC in obtained to be about 22%/E(GeV) Based on the odginal frame of SOBER, a Monte Carlo simulation program for the ESC is developed with a dual Gaussian pulse height spectrtun of the single counter cell. The electromagnetic cascades are calculated by the EGS4 package and a three-dimension magnetic field in the BES is included. The simulation results agree with experimented data well.     

北京谱仪桶部簇射计数器径迹重建方法

介绍了北京谱仪桶部簇射计数器径迹的重建方法,包括簇射径迹(独立簇射)的寻找、簇射的劈裂与合并等;并讨论了重建的性能和结果.     

BES实验数据离线刻度

概述了北京谱仪(BES)各子探测器的实验离线数据刻度,包括主漂移室、飞行时间计数器、簇射计数器和μ子鉴别器.给出了BES1994年D_s运行期间的探测器运行性能,以及数据质量情况.     

THE DESIGN AND CONSTRUCTION OF THE BARREL SHOWER COUNTER FOR BES

The design and construction details of the barrel shower counter for BES are discussed.The barrel shower counter is cylinderical,of 2.5m inner diameter,3.4m outer diameter and 3.85m length,constructed on an aluminum spool of 2.5m diameter,3 cm thickness and 4.23m length.There are 23 layers of lead (0.5r.l. as an absorber) and 24 layers of selfquenching streamer (SQS) tubes.The total weight of the counter is 40,000kg and 80% of 4π sr soild angle coverage.     

TEST BEAM STUDIES OF BES BARREL SHOWER COUNTER PROTOTYPE

The BES barrel shower counter prototype was tested with electron and pion beam in the momentum range from 0.2 to 2.0GeV/c at 12GeV PS test beam line of KEK, the preliminary results were reported. Four types of gas mixtures which were used in prototype have been tested: 40% Ar/60% Isobutane, 44.5% Ar/44.5%CH₄/11% Methylel, 47%Ar/47%%CH₄/6% Methylel, 49.3%Ar/49.3%CH₄/1.4% Ethyl alcohol. The results show that using SQS tube as sampling means in BES shower is feasible way for BEPC region.     

Study of BESⅢ MUC offline software with cosmic-ray data

Cosmic-ray data of 90 M events have been collected and used for calibration, alignment as well as detector tuning. A special tracking algorithm for the BESⅢ muon counter is developed and verified with Monte-Carlo simulation and then further confirmed with the cosmic-ray data. The obtained strip resolutions are in good agreement with the design values. A new alignment approach for the BESⅢ muon counter is confirmed with the cosmic-ray data and proposed to be used in future analysis of experimental data.     

Cluster of scintillation counters for the shower array in the NEVOD EAS project

A shower array for investigations of primary cosmic rays in the knee region in the energy spectrum of extensive air showers is being designed on the basis of the NEVOD experimental complex. Features of the cluster organization of the array and the results of the study of the characteristics of both the basic scintillation counter and the counter cluster, which is the basic element for triggering, detecting, and data collection and treatment systems, are discussed.     

Monte Carlo tuning for the BESⅢ time-of-flight system

Using experimental data, Monte Carlo tuning is implemented for performance parameters associated with the scintillation counters and readout electronics of the BESⅢ time-of-flight (TOF) system, as part of the full simulation model. The implementation of the tuning is described for simulations designed to reproduce the performance of a number of TOF system parameters, including pulse height, hit efficiency, time resolution, dead channels and background. In addition, comparisons with experimental data are presented.     

Das Verhalten eines Anthrazen-Szintillationszählers gegenüber Elektronen niedriger Energie

A study has been made to determine the influence which an anthracene scintillation counter exerts on the detection of low energy external electrons. Since in such an investigation several processes are involved we studied our photomultiplier's single electron line, the line shape of photomultiplier anode pulses for excitation of the scintillator by external electrons with energies from 1 keV to 29 keV, the mean pulse height — energy relation and the relative variance — reciprocal energy relation for these line shapes. We will show a short way to calculate a detection probability as a function of energy absorbed in the crystal.     

THE COSMIC RAY DATA ANALYSIS OF μ-COUNTER ARRAY IN BES

By analysing the cosmic ray data of μ-counter array in BES,we obtained informations on the threshold for identifying signal and noise,the detection efficiency of single wire layer,the particle detection efficiency,and the location resolutions in z direction and in γ-φ plane for μ-counter array.The comparison between eexperimental data and Monte-Carlo simulation showed good agreement.