The performance of Glass GEM

Abstract

Here we report the performance of Glass gas electron multipliers (Glass GEMs), which were fabricated with photo-etchable glass. The photo-etchable glass used for substrate is called PEG3 (Hoya Corporation). With this material, we succeeded in fabricating a Glass GEM that was 680 μ m-thick with a hole diameter of 170 μ m and Cr and Cu layer electrodes. A Glass GEM has advantages such as good uniformity, high gain, a flat surface without stretching, cylindrical holes, and the absence of outgassing from the material. We successfully operated a Glass GEM having 100 × 100 m 2 effective area with various gas mixtures. The energy resolution for 5.9 keV X-rays was 18%, obtained by uniform irradiation of the entire effective area. The gas gain of the Glass GEM reached up to 90,000 with a gas mixture of Ne/C 4 (90:10). The Glass GEM was also operated with Ar/C 4 and Ar/C 4 gas. The gain stability measured for Glass GEM showed no significant increase or decrease as a function of elapsed time from applying high voltage. The gain stability over 15 hours of operation was about 10% in high-count-rate irradiation. Gain mapping across the Glass GEM showed good uniformity with a standard deviation of about 10%.

High-photon-yield scintillation detector with Ar/CF4 and glass gas electron multiplier

“…16) Meanwhile, we have developed a new type of GEM using photoetchable glass, called glass GEM (G-GEM). [17][18][19] The G-GEM has advantages such as high gain, high discharge resistance, stiff substrate, and low outgassing compared with conventional GEMs. In this study, we have developed a high photon yield scintillation detector with G-GEM, using Ar=CF 4 as the scintillation gas.…”

Development of large-area glass GEM

“…We then obtained the spectrum for each section using the same 55 Fe source as previously. A high voltage was applied across the G-GEM for 12 h prior to the measurement in order to exclude the effect of long-term powering, because we had observed the gain decrease effect over time by applying high voltage [10]. The irradiation period of each section was also limited to a sufficiently short time (30 s) for the same reason.…”

“…This selfsupporting capability also enables a simple detector setup, since no tensioning tools are required. To date, we have been continuing research and development of the standard-size 100 Â 100 mm 2 G-GEM, and demonstrating its excellent characteristics [9,10].…”

Development of a Bragg-edge Neutron Transmission Imaging Detector Combined with Micro-structured Boron Cathode and Glass Gas Electron Multiplier

“…The glass GEM uses a glass substrate instead of a thin polyimide foil. (19,20) There are 128269 holes in the 100 × 100 mm 2 glass GEM, and each hole acts as a proportional counter, enabling the signals to be amplified two-dimensionally with a high spatial resolution. To obtain the same electron avalanche amplification at every readout pixel, it is desirable to have a uniform electric field for electron acceleration within every hole.…”