Influence of the bulk resistivity of glass with electronic conductivity on the performance of microstrip gas chamber

Abstract The optimization of parameters of microstrip gas chambers (MSGC) on glass substrata with electronic conductivity is presented. It was shown experimentally that a discharge voltage between anode and cathode strips did not change practically with a decrease of anode width from 13 to 5 μm, while at the same time the gain maximum increased from 1000 to 4800. The change of a conducting pattern thickness from 0.5 to 1.5 μm improved the gain maximum by 30%. The measurements were made of the rate capability of MSGC depending on the glass resistivity going in the range from 0.9 × 10 9 to 2 × 10 12 Ω cm. At higher resistivity the rate capability was limited by the modification of electric field by current flowing along the resistive surface, and therefore the rate capability increased when decreasing the resistivity of the support. At the glass resistivity of about 10 11 Ω cm the rate capability came to plateau, which was the result of the influence of space charge in gas on an electric field. The rate capability on the plateau depended on a gas mixture and a chamber gain, and the value of 10 7 Hz/mm 2 was obtained for an Ar+20% CO 2 gas mixture and a gain of 400 for 8 keV X-rays.