Development of MSGC detectors on diamond film-coated silicon composite substrates

In this paper, diamond film-coated silicon was developed to be used as a substrate in a microstrip gas chamber (MSGC) for the first time. The roughness of the composite substrate was rather low, and the resistivity was in the range of 1010-1011Omega cm. Its capacitance was very small and almost had no variation with frequency. All these results prove that the diamond film/Si composite material is a promising substrate for MSGCs. Using this composite substrate, a MSGC detector with an area of 2 X 2 cm2 was fabricated. The effects of the drift voltage and cathode voltage on the energy resolution for 5.9 keV 55Fe x-rays have been examined in detail and discussed. An energy resolution (the relative full width at half maximum of the x-ray peak) of 12.3% was achieved when the MSGC was operated at a drift voltage of -1000 V and a cathode voltage of -650 V with a gas mixture (90% Ar + 10% CH4).