共查询到20条相似文献,搜索用时 0 毫秒
1.
Design of a neutron-TPC prototype and its performance evaluation based on an alpha-particle test 下载免费PDF全文
HUANG Meng LI Yu-Lan NIU Li-Bo LI Jin DENG Zhi HE Li ZHANG Hong-Yan CHENG Xiao-Lei FU Jian-Qiang LI Yuan-Jing 《中国物理C(英文版)》2015,39(8):086003-086003
A neutron-TPC(n TPC)is being developed for use as a fast neutron spectrometer in the fields of nuclear physics,nuclear reactor operation monitoring,and thermo-nuclear fusion plasma diagnostics.An n TPC prototype based on a GEM-TPC(Time Projection Chamber with Gas Electron Multiplier amplification)has been assembled and tested using argon-hydrocarbon mixture as the working gas.By measuring the energy deposition of the recoil proton in the sensitive volume and the angle of the proton track,the incident neutron energy can be deduced.A Monte Carlo simulation was carried out to analyze the parameters affecting the energy resolution of the n TPC,and gave an optimized resolution under ideal conditions.An alpha particle experiment was performed to verify its feasibility,and to characterize its performance,including energy resolution and spatial resolution.Based on the experimental measurement and analysis,the energy resolution(FWHM)of the n TPC prototype is predicted to be better than 3.2%for 5 Me V incident neutrons,meeting the performance requirement(FWHM5%)for the n TPC prototype. 相似文献
2.
GPM based on THGEM has shown its competitive strength compared to the conventional PMT, espe- cially in the low background research such as dark matter detection. A kind of THGEM made from PTFE, named PTFE-THGEM, is developed for the GPM to be used in CDEX. The PTFE has a lot of advantages especially its low level radioactivity. The PTFE-THGEM was tested at room and cryogenic temperature. It has a high gain in different gases and shows good stability at room temperature. The gain of a single PTFE-THGEM reached 112 at 117 K. The penning effect is also discussed in this paper to explain the "abnormal" phenomena of the gain in different gases. 相似文献
3.
GPM based on THGEM has shown its competitive strength compared to the conventional PMT,especially in the low background research such as dark matter detection. A kind of THGEM made from PTFE,named PTFE-THGEM,is developed for the GPM to be used in CDEX. The PTFE has a lot of advantages especially its low level radioactivity. The PTFE-THGEM was tested at room and cryogenic temperature. It has a high gain in different gases and shows good stability at room temperature. The gain of a single PTFE-THGEM reached 112 at 117 K. The penning effect is also discussed in this paper to explain the “abnormal” phenomena of the gain in different gases. 相似文献
4.
5.
Fu-Yue Wang Yi Wang Bo Xie Dong Han Peng-Fei L& uuml Bao-Hong Guo Yuan-Jing Li 《中国物理C(英文版)》2016,40(11):116006-116006
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. 相似文献
6.
The effects of liquid chlorine donors (BCl3 and CCl4) on the output energy and the efficiency of a KrCl laser (222 nm) are investigated. Maximum laser energies of 230 mJ (3.3 J/l) in pulses of 16 ns duration were obtained from a 0.035% BCl3/10.1% Kr/89.8% Ne mixture at a total pressure of 2600 Torr, and at a specific power loading of about 24 MW/cm3, a power conversion efficiency of 0.86% was obtained. These figures are reduced by a factor of two when He is used as buffer gas. Much weaker laser emissions were obtained when CCl4 was used as a chlorine donor. 相似文献
7.
8.
9.
10.
章爱武 谢宇广 俞伯祥 安正华 王志刚 蔡啸 孙希磊 石峰 方建 薛镇 吕绮雯 孙丽君 葛永帅 刘颖彪 刘宏邦 郑阳恒 谢一冈 胡涛 周莉 吕军光 《中国物理 C》2012,36(10):985-990
A micro-pattern gas detector named leak microstructure (LM) has been studied. A new chemical electrolytic technique is introduced to make perfect shaped LM needles with very sharp tips, and this method may be developed to make LM array detectors in batches. The experimental results are presented for both a single needle LM detector and a small LM array detector. The gas gain is up to 105 by calculation from the waveform. Good gain stability and uniformity are achieved. The light emission from the needle tip is also measured in Ar/CF4(95/5) gas mixture. The result shows a promising application for imaging. 相似文献
11.
12.
转轮除湿空调系统是将转轮除湿机与常用冷却方式相结合实现空调制冷的新型空调系统。为降低转轮除湿空调系统的再生能耗以及提高系统的冷却能力,本文提出双级热管转轮除湿空调系统,系统利用重力热管的冷凝段实现转轮除湿机的再生,蒸发段实现处理空气的冷却。建立了双级热管除湿转轮空调系统传热传湿模型,模拟分析了系统在不同工况下系统的降温除湿特性。研究表明,处理空气进口温度越高,系统的冷却能力越强但系统的除湿能力降低;处理空气湿度越高,系统的除湿能力越强,但系统的冷却能力降低;再生温度越高,系统除湿能力越强,系统热力性能系数越低,但冷却能力降低。综合降温除湿能力及节能要求,双级热管转轮除湿空调系统的再生温度不宜过高,推荐≤80℃。 相似文献
13.
Huajuan Qi Jing GuoKui Wu Yongchuan XiaoXindong Zhang Jingran ZhouCaixia Liu Shengping RuanWei Dong Weiyou Chen 《Optik》2013
An integrated microwave photonic phase shifter based on vector-sum technique in silicon on insulator was verified and designed. The principle of phase-shift was demonstrated and the components were designed in detail. The interference was taken into account in the design and 0.3 nm line-width of a light source was required to make the coherent interference smallest even to be neglected. Owing to the compact size and excellent characteristics of integration, the proposed component has a promising utilization in optical communication and optical phased-array radar. 相似文献
14.
《中国光学快报(英文版)》2017,(11)
A scheme of triangular-shaped pulses with full duty cycle generation is proposed and analyzed.Benefiting from the feature of orthogonal polarization,two approximate sinusoidal signals on different polarization states can be combined without inducing coherent interference.By tuning the time mismatching between the two signals,an approximately triangular-shaped profile can be obtained in the optical intensity.It is found that the modulation index β is no longer a fixed one,but it can be aligned within a proper range of 0.92 to 1.57.To evaluate the proposal,impacts of radio frequency voltage fluctuation,bias voltage drift,and time mismatching are discussed.Within the defined fitting error(η≤ 3%),the tolerable range of the modulation index,time mismatching,and voltage have been found,which insures a simple operation in practice. 相似文献
15.
In this paper, we present the design and construction of a 20 Ci γ-ray Compton spectrometer that employs a137 Cs source with a strong line at 661.65 keV. The total resolution of the spectrometer in momentum scale is 0.40 a.u., which
is much better than the conventional241Am Compton spectrometers. The in-house137Cs spectrometer is very useful for the measurement of momentum densities of heavy materials. The performance of the machine
is assessed using aluminum, terbium and mercury samples and the experimental data from comparable apparatus. 相似文献
16.
17.
P. BeltrameE. Bolle A. BraemC. Casella E. ChesiN. Clinthorne R. De LeoG. Dissertori L. DjambazovV. Fanti C. JoramH. Kagan W. LustermannF. Meddi E. NappiF. Nessi-Tedaldi J.F. OliverF. Pauss M. RafecasD. Renker A. RudgeU. Ruotsalainen D. SchinzelT. Schneider J. SéguinotP. Solevi S. StapnesU. Tuna P. Weilhammer 《Nuclear Physics B - Proceedings Supplements》2011,215(1):34-36
18.
如何使散热器在保持较低流阻的基础上强化其散热性能,成为数据中心服务器冷却问题研究的焦点。通过对不同宽度比U型流道散热器的性能分析,发现宽度比为0.6、0.7或0.8的散热器,同时具有较佳的流动性能和散热性能。设计并制作了β为0.6的U型流道散热器,通过实验分析不同冷却水流量下散热器的芯片温度、热阻以及摩擦因子f,得出散热器最佳的冷却水流量为15 mL/s,以最小的流动损失获取更佳的散热效果。 相似文献
19.
Abstract Phase transitions in praseodymium and lanthanum under pressure have been studied using a synchrotron powder X-ray diffraction technique. A structure refinement of the distorted fcc phase of Pr using diffraction data collected with an imaging plate (IP) detector demonstrate that among some possible structures the rhombohedral structure with space group R3m best reproduces the observed diffraction pattern. The distorted fcc-fcc phase transition in La was observed as a function of the temperature at 23 GPa using a CCD-based detector. A five-minute exposure sufficiently long to measure the intensities of very weak superlattice reflections from the distorted fcc phase, which has been found to transform to the fcc phase at 550 K. The performance of the IP and a CCD-based detector are compared and their future developments discussed. 相似文献
20.
Performance parameter of a Bragg fiber waveguide based resonant sensor in presence of a defect layer in cladding regions is theoretically studied. The Bragg fiber waveguide consists of a liquid-core surrounded by alternate high and low refractive indices materials in cladding regions. Reflectivity of the proposed waveguide based resonant sensor is formulated using transfer matrix method for a non-homogeneous multilayer cylindrical system. The waveguide shows a band gap region with a narrow defect mode in the band gap region under the considered wavelength range. Instead of taking a whole band gap as a sensing signal, here the defect peak is taken as the sensing signal. It is observed that the intensity of defect mode is more sensitive for core refractive index than the intensity of traditional band gap region (lobe). This study shows that the higher sensitivity can be achieved by creating the defect at a position in cladding region where the intensity of transmitted light lies between 40% and 90%. Presence of a defect layer is able to increase the detection accuracy of the sensor and, hence increase the overall performance of this sensor. 相似文献