Development of the micro pixel chamber based on MEMS technology

Abstract

Micro pixel chambers (μ-PIC) are gaseous two-dimensional imaging detectors originally manufactured using printed circuit board (PCEi) technology. They are used in MeV gamma-ray astronomy, medical- imaging, neutron imaging, the search for dark matter, and dose monitoring. The position resolution of the present μ-PIC is approximately 120 μm (RMS), however some applications require a fine position resolution of less than 100 μm. To this end. we have started to develop a μ-PIC based on micro electro mechanical system (MEMS) technology, which provides better manufacturing accuracy than PCB technology. Our simulation predicted the gains of MEMS μ-PICs to be twice those of PCB μ-PICs at the same anode voltage. We manufactured two MEMS n-PlCs and tested them to study their behavior. In these experiments, we successfully operated the fabricated MEMS μ-PICs and we achieved a maximum gain of approximately 7 xlO3 and collected their energy spectra under irradiation of X-rays from -5Fe. However, the measured gains of the MEMS μ-PICs were less than half of the values predicted in the simulations. We postulated that the gains of the MEMS /