Experimental results from a microdot detector overcoated with a semiconducting layer

A Microdot (MDOT) detector has been overcoated with a boron-doped amorphous silicon carbide semiconductive layer. The stable operation of the device in mixtures of argon, neon and helium with di-methyl ether (DME) at high gains and at high counting rates is shown. Radiation damage tests give a lifetime of over 120 mC/cm using a gas system with plastic gas pipes.