Gas Scintillation Imager With Capillary Plate

The glass capillary plate (CP) gas detector is a hole-type micropattern gas detector (MPGD) as well as a gas electron multiplier (GEM). An interesting feature of the hole-type MPGD is that since the electron multiplication takes place in each of the highly granulated holes, pixelized 2-D imaging with a high position resolution is possible. Using the CP, we have been developing a gas scintillation imager (GSI) for digital X-ray radiography, cosmic X-ray polarimetry, and neutron imaging. To realize the 2-D imaging capability, we exploit the visible and near-infrared (NIR) scintillation photons emitted from each hole upon gas excitation. This emission occurs simultaneously with electron multiplication. The readout of the scintillation photons has been carried out using an image-intensified charge-coupled device (CCD) or CMOS camera, or a cooled low-noise CCD/CMOS camera, coupled to an optical mirror or lens systems. In this article, we review the properties of the GSI as X-ray and neutron imagers and describe the outlook for future developments.