Bd. Ramsey et al., A STUDY OF FACTORS LIMITING THE MAXIMUM GAIN IN MICROSTRIP GAS COUNTERS, IEEE transactions on nuclear science, 44(3), 1997, pp. 640-645
It was shown in our previous paper [1] that the maximum achievable gai
n in microstrip Gas Counters (MSGC's) is limited by surface streamers,
which are self-quenched over a very limited voltage region and quickl
y transit to breakdown sparks. In this work we have tried to identify
the main factors governing the maximum gain at which the streamers app
ear, and towards this end have made simulations and tested MSGC's of d
ifferent geometries and on different substrates in both Ar- and Xe-bas
ed gas mixtures at pressures from 0.1 to 3 atm. From these studies we
conclude that in order to reduce surface breakdowns in MSGC's, the mul
tiplication should be concentrated to the narrowest region around the
anode strips and the gas gain elsewhere, especially near the cathodes,
should be maximally suppressed. For this purpose, narrow anodes and g
as mixtures with proper Townsend coefficients should be used. Control
experiments we performed confirm these hypotheses.