气体电子倍增器(GEM,Gas Electron Multiplier)是近些年发展的一种新的气体探测器,具有计数率和位置分辨率高等优点,在粒子物理和X光成像等领域有着广泛的应用前景,近些年来得到了很快的发展.该探测器发展的关键问题之一就是GEM膜结构...气体电子倍增器(GEM,Gas Electron Multiplier)是近些年发展的一种新的气体探测器,具有计数率和位置分辨率高等优点,在粒子物理和X光成像等领域有着广泛的应用前景,近些年来得到了很快的发展.该探测器发展的关键问题之一就是GEM膜结构的制造,该结构需要利用光刻等多项技术来完成,工艺复杂,研制困难.本文介绍了开发GEM膜结构的研究结果,通过干法和湿法腐蚀的研究和对比,优化出GEM膜结构制造的一种工艺过程,并利用该工艺成功完成了GEM膜结构的制造,为国内GEM气体探测器的研究和应用奠定了基础.展开更多
A new inner drift chamber has been built which can replace the aged part of the BESIII drift chamber when needed. The design of the new inner drift chamber can minimize the ineffective area in the very forward and bac...A new inner drift chamber has been built which can replace the aged part of the BESIII drift chamber when needed. The design of the new inner drift chamber can minimize the ineffective area in the very forward and backward region and hence reduce the background event rate. With this design, the new inner drift chamber is expected to have a longer lifetime and improved performance due to the lower occupancy. The endplates and the cylinder were machined with high precision. Wire stringing was performed after the mechanical structure was assembled, and good quality of wire stringing was ensured by measurement of the tension and leakage current of the wires. After completion of the physical construction of the new chamber, a cosmic-ray test was carried out to test its performance. The results of the cosmic-ray test show that the new inner chamber achieves a spatial resolution of127 μm and a d E/dx resolution of 6.4%, which satisfies the design specifications.展开更多
The neutrino detector for the Jiangmen Underground Neutrino Observatory（JUNO） requires a large number of photomultiplier tubes（PMTs）, including 15000 MCP PMTs and 5000 dynode PMTs. The TTS（transit time spread） o...The neutrino detector for the Jiangmen Underground Neutrino Observatory（JUNO） requires a large number of photomultiplier tubes（PMTs）, including 15000 MCP PMTs and 5000 dynode PMTs. The TTS（transit time spread） of the PMTs is very important for vertex and track reconstruction of the neutrinos in the detector. In this paper, we study the TTS of a 20-inch dynode PMT（R12860） from Hamamatsu for different high voltage, light intensity, light spot size and different photocathode regions. The impact from Earth＇s magnetic field is also studied.The results achieved in this paper will be very useful for the JUNO experiment.展开更多
文摘气体电子倍增器(GEM,Gas Electron Multiplier)是近些年发展的一种新的气体探测器,具有计数率和位置分辨率高等优点,在粒子物理和X光成像等领域有着广泛的应用前景,近些年来得到了很快的发展.该探测器发展的关键问题之一就是GEM膜结构的制造,该结构需要利用光刻等多项技术来完成,工艺复杂,研制困难.本文介绍了开发GEM膜结构的研究结果,通过干法和湿法腐蚀的研究和对比,优化出GEM膜结构制造的一种工艺过程,并利用该工艺成功完成了GEM膜结构的制造,为国内GEM气体探测器的研究和应用奠定了基础.
文摘A new inner drift chamber has been built which can replace the aged part of the BESIII drift chamber when needed. The design of the new inner drift chamber can minimize the ineffective area in the very forward and backward region and hence reduce the background event rate. With this design, the new inner drift chamber is expected to have a longer lifetime and improved performance due to the lower occupancy. The endplates and the cylinder were machined with high precision. Wire stringing was performed after the mechanical structure was assembled, and good quality of wire stringing was ensured by measurement of the tension and leakage current of the wires. After completion of the physical construction of the new chamber, a cosmic-ray test was carried out to test its performance. The results of the cosmic-ray test show that the new inner chamber achieves a spatial resolution of127 μm and a d E/dx resolution of 6.4%, which satisfies the design specifications.
基金Supported by Strategic Priority Research Program of the Chinese Academy of Sciences(XDA10011100)National Natural Science Foundation of China(U1431109,11265003)
文摘The neutrino detector for the Jiangmen Underground Neutrino Observatory（JUNO） requires a large number of photomultiplier tubes（PMTs）, including 15000 MCP PMTs and 5000 dynode PMTs. The TTS（transit time spread） of the PMTs is very important for vertex and track reconstruction of the neutrinos in the detector. In this paper, we study the TTS of a 20-inch dynode PMT（R12860） from Hamamatsu for different high voltage, light intensity, light spot size and different photocathode regions. The impact from Earth＇s magnetic field is also studied.The results achieved in this paper will be very useful for the JUNO experiment.
