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arXiv 1804.04643physics.ins-det
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具有内置电极网的多层厚气体电子倍增器- MM-THGEM的首次性能评价

First performance evaluation of a Multi-layer Thick Gaseous Electron Multiplier with in-built electrode meshes - MM-THGEM

Rui de Olivera, Marco Cortesi

摘要:

我们描述了一种新的微图案气体检测器结构,包括一个多层孔型倍增器(M-THGEM)结合两个内置的电极网格:多网格THGEM型倍增器(MM-THGEM)。施加在各个电极之间的合适的电势差提供了MM-THGEM孔内的电离电子的有效收集和网格之间的大电荷雪崩倍增。不同于传统的空穴型倍增器(例如,气体电子倍增器-GEM、厚气体电子倍增器-THGEM等),其特征在于雪崩间隙内的可变(类偶极)场强,MM-THGEM中的电子很大程度上被在两个网格之间建立的强均匀场倍增,如在平行板雪崩几何结构中。孔内两个网格的存在允许捕获流回漂移区的大部分正离子。在Ar/(10%)CH_4和He/(10%)CO_2中,在标准的温度和压力条件下,用单个MM-THGEM进行单个光电子探测,气体增益超过10^5。当MM-THGEM与常规THGEM耦合并用作第一级联元件时,在He/(10%)CO2中最大可实现增益达到10^6以上,而在最佳探测器偏压配置的情况下,IBF接近1.5%。该IBF值比双GEM/THGEM检测器获得的IBF值低几倍(5-10%),并且与Micromegas检测器获得的性能相当。

英文摘要:

We describe a new micro-pattern gas detector structure comprising a multi-layer hole-type multiplier (M-THGEM) combined with two in-built electrode meshes: the Multi-Mesh THGEM-type multiplier (MM-THGEM). Suitable potential differences applied between the various electrodes provide an efficient collection of ionization electrons within the MM-THGEM holes and a large charge avalanche multiplication between the meshes. Different from conventional hole-type multipliers (e.g. Gas Electron Multipliers - GEMs, Thick Gas Electron Multipliers - THGEMs, etc.), which are characterized by a variable (dipole-like) field strength inside the avalanche gap, electrons in MM-THGEMs are largely multiplied by a strong uniform field established between the two meshes, like in the parallel-plate avalanche geometry. The presence of the two meshes within the holes allows for the trapping of a large fraction of the positive ions that stream back to the drift region. A gas gain above 10^5 has been achieved for single photo-electron detection with a single MM-THGEM in Ar/(10%)CH4 and He/(10%)CO2, at standard conditions for temperature and pressure. When the MM-THGEM is coupled to a conventional THGEM and used as first cascade element, the maximum achievable gains reach values above 10^6 in He/(10%)CO2, while the IBF approaches of 1.5% in the case of optimum detector-bias configuration. This IBF value is several times lower compared to the one obtained by a double GEM/THGEM detector (5-10%), and equivalent to the performance attained by a Micromegas detector.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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