Presentation Information
[8p-E204-7]Large-Area Glass GEM Detector with FPD Analog Front-End-Based Electrical Readout
〇Moh Hamdan1,2, Yuki Mitsuya1, Setsuo Sato1, Hiroyuki Takahashi1,2 (1.The University of Tokyo, 2.Fukushima Institute for Research, Education and Innovation)
Keywords:
Micropattern Gaseous Detector,Glass Gas Electron Multiplier,FPD Analog Front End Electronics
The Glass Gas Electron Multiplier (G-GEM) has been widely studied for radiation imaging applications because of its high charge gain exceeding 104, high spatial resolution, large sensitive area up to 280 × 280 mm2, and low outgassing characteristics. Electrical readout is attractive because it enables direct detection of avalanche charges and provides energy and timing information. However, large-area imaging with fine-pitch readout requires a large number of channels, increasing system complexity, power consumption and cost. In this study, a pulse-counting electrical readout system based on a Flat Panel Detector Analog Front End (FPD-AFE) was developed for a large-area 280 × 280 mm2 G-GEM detector. A two-dimensional strip-pad readout board with a sensitive area of 280.4 × 280.4 mm2 was developed using orthogonal strip electrodes and a via-in-pad structure. The board incorporates 560 strips in both the X and Y directions with a pitch of 500 μm and a total of 313,040 pads. An electronics module integrating protection circuit, AFE, ADC, FPGA, and discharge-rejection circuits was developed and connected to the readout board. Each module handles 128 channels, and ten modules are used for detector readout. The AFE employs multiplexed charge readout inspired by flat-panel detector electronics. A 100 × 100 mm2 G-GEM coupled to the readout board and electronics was evaluated using a 90Sr beta-ray source. A two-dimensional hit map was successfully reconstructed using a center-of-gravity (COG) algorithm from 20 min of irradiation data. Further validation will be performed using a large-area G-GEM detector.