P. Siritiprussamee

Multichannel CMOS ASIC preamplifiers for avalanche photodiode and microstrip gas chamber readouts

A 10-channel (Ch) and a 16-Ch application specific integrated circuit (ASIC) preamplifier chip with telescopic-cascode topology and gain-boosted (regulated) cascode topology respectively has been designed for avalanche photodiode (APD) and microstrip gas chamber (MSGC) readouts. These highly integrated and reliable chips can be used for individual readouts from many channels to improve the spatial resolution and counting rate of such detectors over light sharing or charge division schemes. These chips were fabricated on a 2.4 times2.4 mm die area using ROHM 0.35-mu CMOS technology. The chips were tested to have a low optimum equivalent noise charge (ENC) of about 880 e

Development of front end electronics for M-MSGC using individual-readout ASIC with resistive strip output

at a shaping time of 0.5 mus. The voltage output to charge input gains of the 10-Ch and 16-Ch preamplifiers are 0.71/pf and 0.91/pf while the rise times (10%-90%) are 15 and 13 ns, respectively. The 16-Ch chip was used to readout a GSO-APD detector and an optimum energy resolution of 11.3% (511 Kev peak of Na-22) was obtained while the coincidence time resolution with two such detectors is about 12.5 ns. The energy resolution of the 5.9 keV peak from a Fe-55 source obtained with a 3 times3 cm MSGC plate was about 20.5%

Development of a 2-dimensional multigrid-type MSGC using GLG method for the new generation spallation neutron sources

A multi-grid-type microstrip gas chamber (M-MSGC) is being developed for the new spallation neutron source in Japan. The objective of this study is to provide a new position readout electronics for two-dimensional M-MSGC which can reduce the number of interconnections through a gas vessel by using a new encoding readout scheme based on ASIC technology. In order to test an ASIC based individual readout method, an ASIC chip, which has typically 16 individual input channels, has been designed and fabricated using a ROHM 0.35µ;m CMOS process and the chip was connected to a developed encoding circuit. The main results of the performance test indicated that the front-end electronics was able to encode 1500 pixels of the input position with 4.4% of position non-linearity. The results of this work confirm that the developed circuit would be appropriate for the front-end electronics of He-3 two-dimensional M-MSGC.

Multi-channel CMOS ASIC preamplifiers for APD and MSGC readouts

The neutron detector is one of the key components for the new generation spallation neutron source facilities. We have developed the multigrid-type MSGC(M-MSGC) with He-3 gas as a promising candidate for the new spectrometers. M-MSGC is improved on the ordinal MSGC with putting grids between anodes and cathodes for preventing discharge between electrodes and accumulation of charge on the surface. Moreover, we developed new read out method called as GLG method. Signals are encoded to two groups in this method. One group is named as global, which indicates the coarse position and the other group is local, which shows detail position in a global pattern. A period of the local pattern is corresponding to a global in length. We fabricated a GLG plate, which has 10 times 10 cm2 of active area and 64 readout channels. Then the plate was tested at KEK photon factory as preliminary experiment for neutron detection. In the results, we could demonstrate the usability of the GLG readout method

Development of a two-dimensional multi-grid-type microstrip gas chamber using global-local grouping method

A 10-channel (Ch) and a 16-Ch application specific integrated circuit (ASIC) preamplifier chip with telescopic-cascode topology and gain-boosted folded-cascode topology respectively has been designed for avalanche photodiode (APD) and microstrip gas chamber (MSGC) readouts. These highly integrated and reliable chips can be used for individual readout from many channels to improve the spatial resolution and counting rate of such detectors over light sharing or charge division schemes. These chips were fabricated on a 2.4 mm times 2.4 mm die area using ROHM 0.35 mu CMOS technology. The chips were tested to have a low optimum equivalent noise charge (ENC) of about 880 e-. The gains of the 10-Ch and 16-Ch preamplifiers are (1.4-pF)-1 and (1.1-pF)-1 while the rise times are 15 s and 13 s respectively. The 16-Ch chip was used to readout GSO-APD detectors and an optimum energy resolution of 11.3% (551 keV peak of Na-22) was obtained while the coincidence time resolution with a BaF2 detector is about 11.5 ns. The energy resolution of Fe-55 with a 3 times 3 cm MSGC plate is about 20.5%.

Development of a two-dimensional multi-grid-type microstrip gas chamber for spallation neutron source

In this paper we propose a new type of 2D M-MSGC using multi-layer technology. In order to reduce the number of readout lines without image distortion, we introduce a new encoding scheme, the global-local grouping (GLG) method. In this approach global and local signals are used to locate the coarse and fine position information, respectively. We have designed, fabricated and tested the GLG M-MSGC plate with an active area of 10/spl times/10 cm/sup 2/. The results confirmed that the principal of 2D G-LG M-MSGC is successful.