Soda glass capillary plate gas detector

A new capillary plate (CP) has been developed for a hole-type micropattern gas detector. The plate consists of a bundle of fine soda-glass capillaries of 100 μm in diameter with a uniform length of 1 mm. The electrodes on the surfaces of both ends were coated with Inconel metal. It is similar to the conventional CP, except that the glass is not lead glass, but soda glass. The main advantages compared to the lead-glass CP are the low surface resistivity and the low background properties. The soda-glass CP gas detector was operated with a gas mixture of Ar(90%) + CH₄(8%) + TMA(2%) using 5.9 keV X-rays. We successfully obtained the energy spectrum and the accumulated image for the 5.9 keV X-rays. We report on the characteristics of the new soda-glass CP and the background properties of both the soda-glass and lead-glass CPs. We also describe the outlook on the future development of an optical gas photomultiplier with the soda-glass CP.