共查询到20条相似文献,搜索用时 15 毫秒
1.
In order to take away much more heat on the BESⅢ beam pipe to guarantee the normal particle detection,EDM-1(oil No.1 for electric discharge machining),with good thermal and flow properties was selected as the candidate coolant for the central beryllium pipe of the BESⅢ beam pipe.Its cooling character was studied and dynamic corrosion experiment was undertaken to examine its corrosion on beryllium.The experiment results show that EDM-1 would corrode the beryllium 19.9 μm in the depth in 10 years,which is weak and can be neglected.Finite element simulation and experiment research were taken to check the cooling capacity of EDM-1.The results show that EDM-1 can meet the cooling requirement of the central beryllium pipe.Now EDM-1 is being used to cool the central beryllium pipe of the BESⅢ beam pipe. 相似文献
2.
A prototype multi-gap resistive plate chamber (MRPC) with a 2×6 gap structure is developed for the upgrading of the endcap time-of-flight (ETOF) detector in the Beijing Spectrometer (BESⅢ). The prototype MRPC is tested in the E3 beam line of the Beijing Electron Positron Collider (BEPC) with secondary charged particles (π and p, etc) of 600 MeV/c. The test results show that the time resolution of the MRPC can reach 50 ps and that the detection efficiency is greater than 98%. 相似文献
3.
WU Zhi LIU Jian-Bei QIN Zhong-Hua WU Ling-Hui CHEN Chang CHEN Yuan-Bo CHEN Ma-Li CHEN Xi-Hui DONG Ming-Yi GUAN Bei-Ju HUANG Jie JIANG Xiao-Shan JIN Yan LI Fei LI Ren-Ying LI Xiao-Nan LEI Guang-Kun LIU Rong-Guang LUO Xiao-Lan MA Xiao-Yan SHENG Hua-Yi SUN Han-Sheng TANG Xiao WANG Lan WANG Liang XU Mei-Hang ZHANG Jian ZHANG Hong-Yu ZHANG Yin-Hong ZHAO Yu-Bin ZHAO Ping-Ping ZHU Ke-Jun ZHU Qi-Ming ZHUANG Bao-An 《中国物理C(英文版)》2010,34(7)
The BESⅢ drift chamber and its subsystems need a cosmic-ray test after the chamber construction to check the chamber construction quality,testing the joint operation of the whole system and the performance of the chamber.The noise performance,drift time and charge measurements,and the scanning of channels were examined specifically.The preliminary results of the test indicate that the whole system works well. 相似文献
4.
To monitor the integral dose deposited in the BESⅢ electromagnetic calorimeter whose perfor-mance degrades due to exposure to the BEPCⅡ background, a 400 nm IMPL RadFET dosimeter-based integral dose online monitor system is built. After calibration with the 60Co source and verification with TLD in the pulse radiation fields, an experiment was arranged to measure the BEPC Ⅱ background online. The results are presented. 相似文献
5.
XIE Yu-Guang LI Wei-Dong LIANG Yu-Tie YOU Zheng-Yun MAO Ya-Jun ZHANG Jia-Wen BIAN Jian-Ming CAO Guo-Fu CAO Xue-Xiang CHEN Shen-Jian DENG Zi-Yan FU Cheng-Dong GAO Yuan-Ning HE Kang-Lin HE Miao HUA Chun-Fei HUANG Bin HUANG Xing-Wao JI Xiao-Bin LI Fei LI Hai-Bo LIU Chun-Xiu LIU Huai-Min LIU Qiu-Guang LIU Suo LIU Ying-Jie MA Qiu-Mei MA Xiang MAO Ze-Pu MO Xiao-Hu PAN Ming-Hua PANG Cai-Ying PING Rong-Gang QIN Ya-Hong QIU Jin-Fa SUN Sheng-Sen SUN Yong-Zhao WANG Ji-Ke WANG Liang-Liang WEN Shuo-Pin WU Ling-Hui XU Min YAN Liang YUAN Chang-Zheng YUAN Ye ZHANG Bing-Yun ZHANG Chang-Chun ZHANG Jian-Yong ZHANG Xue-Yao ZHANG Yao ZHENG Yang-Heng ZHU Ke-Jun ZHU Yong-Sheng ZHU Zhi-Li ZOU Jia-Heng 《中国物理C(英文版)》2010,34(3)
The calibration algorithm for RPC-based muon detector at BESⅢ has been developed. The calibration method, calibration error and algorithm performance are studied. The primary results of efficiency and noise at layer, module and strip levels have been calibrated with cosmic ray data. The calibration constants are available for simulation and reconstruction tuning. The results of Monte Carlo and data are also compared to check the validation and reliability of the algorithm. 相似文献
6.
Lü Qi-Wen 《中国物理C(英文版)》2009,33(8)
The reconstruction algorithm for BESⅢ Muon Counter, MucRecAlg, is developed with the object-oriented language C++ in BESⅢ offline software environment. MucRecAlg consists of the following functions: to find track seeds either from extrapolation of tracks in the main drift chamber or from the fired strips in muon counter, to select fired strips associated to the candidate tracks, to fit the candidate tracks with a linear or quadratic function and to calculate other parameters of the tracks for muon identification. Monte Carlo samples are generated to check the performance of the reconstruction package, such as reconstruction efficiency, muon remaining rate and pion rejection rate, etc. The preliminary results show that the pion rejection rate is around 3%-4% while the muon remaining rate is better than 90% in 0.4-1.6 GeV/c momentum region, which meets the requirement as shown in the design report. 相似文献
7.
PING Rong-Gang 《中国物理C(英文版)》2008,32(8):599-602
We present a brief remark and introduction to event generators for tau-charm physics currently used at BESⅢ,including KKMC,BesEvtGen,Bhlumi,Bhwide,Babayaga and inclusive Monte-Carlo event generators.This paper provides basic information on event generators for BESⅢ users. 相似文献
8.
WANG Zhi-Gang L Jun-Guang HE Kang-Lin AN Zheng-Hua CAI Xiao DONG Ming-Yi FANG Jian HU Tao LIU Wan-Jin L Qi-Wen NING Fei-Peng SUN Li-Jun SUN Xi-Lei WANG Xiao-Dong XUE Zhen YU Bo-Xiang ZHANG Ai-Wu ZHOU Li 《中国物理C(英文版)》2009,33(10)
The BESⅢ detector has a high-resolution electromagnetic calorimeter which can be used for low momentum μ-π identification.Based on Monte Carlo simulations, μ-π separation was studied.A multilayer perceptron neural network making use of the defined variables was used to do the identification and a good μ-π separation result was obtained. 相似文献
9.
Data quality monitoring (DQM) plays an important role in data taking at the BESⅢ experiments. DQM is used to monitor detector status and data quality. A DQM framework (DQMF) has been developed to make it possible to reuse the BESⅢ offline reconstruction system in the online environment. In this framework, the DQMF can also simulate a virtual data taking environment, transfer events to the event display, publish histograms to a histogram presenter in a fixed interval, and dump histograms into a ROOT file. The DQMF has been stably running throughout BESⅢ data taking. 相似文献
10.
A method to estimate the efficiency of event start time determination at BESIII is developed.This method estimates the efficiency at the event level by combining the efficiencies of various tracks(e,μ,π,K,p,γ)in a Bayesian way.Efficiencies results and the difference between data and MC at the track level are presented in this paper.For a given physics channel,event start time efficiency and systematic error can be estimated following this method. 相似文献
11.
The installation of the BESⅢ RPC system has been completed. Cosmic ray test results show that they perform very well in streamer mode and meet the BESⅢ requirements. We have tested several RPCs in the avalanche mode with the addition of extra SF6 in the gas mixture. We find an efficiency plateau that reaches ~95%, and a time resolution of 1.8 ns. This demonstrates that the BESⅢ-type RPC can work in the avalanche mode as well. 相似文献
12.
WANG Ji-Ke MAO Ze-Pu BIAN Jian-Ming CAO Guo-Fu CAO Xue-Xiang CHEN Shen-Jian DENG Zi-Yan FU Cheng-Dong GAO Yuan-Ning HE Kang-Lin HE Miao HUA Chun-Fei HUANG Bin HUANG Xing-Tao JI Xiao-Sin LI Fei LI Hai-Bo LI Wei-Dong LIANG Yu-Tie LIU Chun-Xiu LIU Huai-Min LIU Suo LIU Ying-Jie MA Qiu-Mei MA Xiang MAO Ya-Jun MO Xiao-Hu PAN Ming-Hua PANG Cai-Ying PING Rong-Gang QIN Ya-Hong QIU Jin-Fa SUN Sheng-Sen SUN Yong-Zhao WANG Liang-Liang WEN Shuo-Pin WU Ling-Hui XIE Yu-Guang XU Min YAN Liang YOU Zheng-Yun YUAN Chang-Zheng YUAN Ye ZHANG Bing-Yun ZHANG Chang-Chun ZHANG Jian-Yong ZHANG Xue-Yao ZHANG Yao ZHENG Yang-Heng ZHU Ke-Jun ZHU Yong-Sheng ZHU Zhi-Li ZOU Jia-Heng 《中国物理C(英文版)》2009,33(10)
A track fitting algorithm based on the Kalman filter method has been developed for BESⅢ of BEPCⅡ.The effects of multiple scattering and energy loss when the charged particles go through the detector,non-uniformity of magnetic field (NUMF) and wire sag, etc., have been carefully handled.This algorithm works well and the performance satisfies the physical requirements tested by the simulation data. 相似文献
13.
YAN Liang HE Kang-Lin LI Wei-Guo BIAN Jian-Ming FU Cheng-Dong HUANG Bin LIU Ying L Qi-Wen NING Fei-Peng SUN Sheng-Sen XU Min ZHANG Jian-Yong ZHU Yong-Sheng 《中国物理C(英文版)》2010,34(2)
In this paper,the kinematic fitting with the Lagrange multiplier method has been studied for BESⅢ experiment.First we introduce the Lagrange multiplier method and implement kinematic constraints.Then we present the performance of the kinematic fitting algorithm.With the kinematic fitting,we can improve the resolution of track parameters and reduce the background. 相似文献
14.
A method to determine precisely three-dimensional wire positions in the BESⅢ drift chamber using physics events is introduced. In part the proposed technique takes advantage of the possibility that the magnetic field can be turned off, thereby providing a huge sample of straight tracks for which effects due to multiple scattering, energy loss and non-uniformity of the magnetic field are minimized during the calibration process. A toy Monte Carlo study is performed to demonstrate the viability of the method. As a result of the calibration process, the rms of the distribution of wire position deviation is reduced from 35μm to 10μm. 相似文献
15.
Event generators at BESⅢ 总被引:1,自引:0,他引:1
We present a brief remark and introduction to event generators for tau-charm physics currently used at BESⅢ, including KKMC, BesEvtGen, Bhlumi, Bhwide, Babayaga and inclusive Monte-Carlo event generators. This paper provides basic information on event generators for BESⅢ users. 相似文献
16.
17.
Offline calibration plays an important role in BES offline data processing. In order to achieve good spatial and momentum resolution, it is necessary to implement high precision offline calibration for the BES drift chamber. This paper studies the time-to-distance relations, which are important calibration constants for track reconstruction. The parameterization of the time-to-distance relation, studies of left-right asymmetry and studies of variation with entrance angle are performed. The impact of dead channels on the time-to-distance relation is given special attention in order to reduce the shift in measured momentum for tracks passing near dead cells. Finally we present the resolutions for barrel Bhabha events(|cos θ|< 0.8) from a J/ψ data set taken in 2012. The average spatial resolution is 123 μm and the momentum resolution for 1.548 Ge V/c Bhabha tracks is 11.9 Me V/c. 相似文献
18.
王纪科 毛泽普 边渐鸣 曹国富 曹学香 陈申见 邓子艳 傅成栋 高原宁 何康林 何苗 花春飞 黄彬 黄性涛 季晓斌 李飞 李海波 李卫东 梁羽铁 刘春秀 刘怀民 刘锁 刘英杰 马秋梅 马想 冒亚军 莫晓虎 潘明华 庞彩莹 平荣刚 秦亚红 邱进发 孙胜森 孙永昭 王亮亮 文硕频 伍灵慧 谢宇广 徐敏 严亮 尤郑昀 苑长征 袁野 张炳云 张长春 张建勇 张学尧 张瑶 郑阳恒 朱科军 朱永生 朱志丽 邹佳恒 《中国物理 C》2009,33(3):210-216
Software alignment is quite important for a tracking detector to reach its ultimate position accuracy and momentum resolution. We developed a new alignment algorithm for the BESⅢ Main Drift Chamber using the Kalman Filter method. Two different types of data which are helix tracks and straight tracks are used to test this algorithm, and the results show that the design and implementation is successful. 相似文献
19.
The prototype of a time digitizing system for the BESⅢ endcap TOF (ETOF) upgrade is introduced in this paper. The ETOF readout electronics has a distributed architecture. Hit signals from the multi-gap resistive plate chamber (MRPC) are signaled as LVDS by front-end electronics (FEE) and are then sent to the back-end time digitizing system via long shield differential twisted pair cables. The ETOF digitizing system consists of two VME crates, each of which contains modules for time digitization, clock, trigger, fast control, etc. The time digitizing module (TDIG) of this prototype can support up to 72 electrical channels for hit information measurement. The fast control (FCTL) module can operate in barrel or endcap mode. The barrel FCTL fans out fast control signals from the trigger system to the endcap FCTLs, merges data from the endcaps and then transfers to the trigger system. Without modifying the barrel TOF (BTOF) structure, this time digitizing architecture benefits from improved ETOF performance without degrading the BTOF performance. Lab experiments show that the time resolution of this digitizing system can be lower than 20 ps, and the data throughput to the DAQ can be about 92 Mbps. Beam experiments show that the total time resolution can be lower than 45 ps. 相似文献