Simulation and optimization of a double THGEM detector

A double thick GEM (THGEM) detector with thin THGEM foils and small holes was constructed. In order to optimize the operation parameters of the detector, a simulation study of the detector was carried out using ANSYS and Garfield program. Some important characteristics, including primary electron transparency, avalanche development and the secondary electron loss were calculated. Parameters, such as electric field and gas choice were optimized.

Study of a sealed high gas pressure THGEM detector and response of alpha particle spectra

A sealed high gas pressure detector working in pure argon is assembled.It consists of a 5 cm × 5 cm PCB THGEM（THick Gaseous Electron Multiplier）.The detector structure and experimental setup are described.The performance under high pressure（2 atm） is examined,selecting optimal voltages for the ionization region and induction region.The dependence of the shape of alpha particle spectra measured with relative gas gain on gas pressure（1.3-2.0 atm） has been studied.Eight data sets of relative gas gain versus working voltage of THGEM,expressed by weighting field E/P,are normalized,consistent with theory.The results show that the air tightness of the chamber is good,measured by a sensitive barometer and checked with gas gain.The experimental results are compared with Monte Carlo simulation of energy deposition without gas gain involved.

Development of alpha surface contamination monitor based on THGEM for contamination distribution

In cases of high radiation emergencies,we propose a surface contamination monitor(SCM)that can quickly measure and pinpoint the contamination distribution in the affected population.Thick gaseous electron multiplier(THGEM)has several advantages,including fast response time and good spatial resolution.Based on new THGEMs,a two-dimensional imaging detector was developed for alpha detection,with a position resolution greater than 3 mm.The detector design and test results are described in this paper.Fast radiation imaging SCMs,with a 40mm×40 mm sensitive area,are currently under development.

Status of the Streamer Mode in Gas Detectors

This work shows the results of a streamer discharge mode studies in various gas detectors developed up-to-date. The results are based on a new experimental data from high-speed thin-gap gas detector application developments as well as on basic knowledge of multi-wire devices operations.

Experimental research on a THGEM-based thermal neutron detector

A new thermal neutron detector with a domestically produced THGEM （Thick Gas Electron Multiplier） was developed as an alternative to 3He to meet the needs of the next generation of neutron facilities. One type of Au-coated THGEM was designed specifically for neutron detection. A detector prototype has been developed and the preliminary experimental tests are presented, including the performance of the Au-coated THGEM working in At/CO2 gas mixtures and the neutron imaging test with 252 Cf source, which can provide the reference for experimental data for research in the future.

基于厚GEM的宽量程γ剂量率探测器研究

厚型气体电子倍增器是一种近10年迅速发展并逐步在多个领域得到应用的气体探测器,具有死时间小、动态范围大、n/γ排斥比高等优点。除了在高能粒子探测、辐射成像等方面的应用外,厚GEM在辐射防护领域也表现出较好的应用潜力。该研究对厚GEM进行建模,仿真计算不同结构、不同灵敏区尺寸以及不同GEM膜厚度时,厚GEM探测器对γ射线的探测效率,在此基础上采用新型基底材料和自主印制电路板技术设计并制作了具有良好稳定性的厚GEM膜,其单层增益可达2×10^(4),工作电压范围超过150 V,探测效率满足辐射监测的需求。利用新研制的GEM膜制作了探测器,设计并搭建了计数模式和电流模式两种信号读出电路。经测试,该探测器对^(137)Cs和^(60)Co的γ射线实现了0.3×10^(−6) Gy/h~8 Gy/h宽量程范围的γ剂量率监测。

THGEM探测器X光斑寻迹和位置分辨实验研究

介绍了一种基于THGEM的X射线光斑寻迹探测器,用于X射线单光子计量技术研究和测量,探测器有效面积200 mm×200 mm,采用128路基于ASIC和FPGA的高速读出电子学,探测器分为中间高分辨区和外围低分辨区两部分,两部分共用一套读出电子学。实验在中国计量科学研究院利用X光机产生的束线,测试光斑位置、光斑精细分布以及探测器的位置分辨。实验结果表明,探测器实现了同时对光斑寻迹和光斑的精细测量,探测器中间高分辨区x方向的位置分辨率为0.63 mm(FWHM),y方向位置分辨率为0.62mm(FWHM),探测器各项性能指标均达到了预期目标。