Micromegas prototypes with thermo-bond film separators

In this paper we report the results of Micromegas prototypes constructed by attaching micromesh to an anode using thermo-bond films. The excellent metal attaching ability and good dielectical property of this kind of film make it a promising material to be used as avalanche gap spacers. Several prototypes are successfully made. The electron transmission properties are first studied and then the gas gain is measured in argon-isobutane mixtures. The maximum gain of more than 10⁴ is easily obtained. The energy resolutions for ⁵⁵Fe 5.9 keV K_α ray can be better than 20% over one magnitude in gain for different operational gas mixtures and the best energy resolution of 13.7% (FWHM) can be achieved with the gas mixture of 94% argon concentration. The preliminary test results of the prototypes with sensitive area of 45 mm×45 mm without internal support show good uniformity across the sensitive area.     

A new gaseous detector — micro mesh gaseous structure

The structure and working principle of Micromegas （MICRO Mesh Gaseous Structure） is discussed. Some radiation sources of α and X rays are used to test this detector. The optimized electric-field intensity of the conversion gap is obtained. The transmission of electrons and the uniformity of the amplification gap are also presented. The energy resolution of the 5.9 keV peak is better than 27%.     

2×4双层结构MRPC的宇宙线测试结果

研制了一种新的2×4双层结构多气隙电阻板室探测器(MRPC),宇宙线测试结果表明,2×4双层结构MRPC有较低的工作电压和较长的工作坪区,探测效率90%以上,时间分辨可以达到100ps.     

Performance evaluation of a parallel-hole collimated detector module for animal SPECT imaging

We have built and investigated a detector module for animal SPECT imaging, especially for use in large field of view (FOV) conditions. The module consists of a PMT-based detector and a parallel-hole collimator with an effective area of 80 mm × 80 mm. The detector is composed of a NaI scintillation crystal array coupled to four H8500 position sensitive photomultiplier tubes (PS-PMT). The intrinsic energy resolution of the detector is 11.5% at 140 keV on average. The planar spatial resolution of the module changes from 2.2 mm to 5.1 mm at different source-to-collimator distances with an unchanged sensitivity of about 34cps/MBq. Additionally, the SPECT Micro Deluxe Phantom imaging was performed with a radius of rotation (ROR) of 40 mm. Using the FBP reconstruction algorithm, a high performance image was obtained, indicating the feasibility of this detector module.     

2×4双层结构MRPC的宇宙线测试结果

研制了一种新的2×4双层结构多气隙电阻板室探测器（MRPC）,宇宙线测试结果表明,2×4双层结构MRPC有较低的工作电压和较长的工作坪区,探测效率90％以上,时间分辨可以达到100ps．     

3D simulation of micromegas detector performance

Micromegas （MICRO MEsh GAseous Structure） is a position-sensitive gaseous detector. It is widely used in particle physics. We present the results of full 3D Monte Carlo simulations of Micromegas performance, taking into account all the processes from the primary ionization, the elctron collection efficiency, and the gain to the signal formation. The simulation results are in good agreement with experimental data.     

Micromegas探测器的电子透过率与增益

介绍了以鱼线作为放大区(雪崩区)支撑柱的Micromegas探测器,探测器灵敏面积为45mm×45mm.给出了该探测器的增益均匀性、电子透过率以及不同气体成分下的增益曲线,并与三维蒙特卡罗模拟结果进行比较.分析讨论了Micromegas工作机理和增益增加的原因等.     

试论如何使用竖直三角形法解决输电线路施工中的量距问题

工程测量技术到目前为止经历了一个比较长的发展时期，一些高科技测量技术的诞生，很大程度上满足了工程测量的需求。但是在铁路、隧道、公路等一些地形特殊的大型输电线路的施工中，还是存在一些量距问题。特别在测量中遇到高大障碍物要测量，或者遇到需跨越式测量而无法得到平距等情况，就需要用三角形测量法这种特殊的量距方法。本文通过对工程测量技术的发展和其重要性的分析，探讨三角形测量法中的竖三角形测量法在解决输电线路施工量距问题中的应用。