I. Introduction
A MICROSTRIP gas chamber (MSGC) has several advantages compared with a multiwire proportional chamber (MWPC): precision and mechanical stability of the strips, reproducibility of the fabrication, better counting rate, and better position resolution. But it has also some disadvantages: its maximum amplification gain is significantly lower, and it is not resistant to sparks induced by highly ionizing particles. Furthermore, charging up of the surface and electrochemical reaction of the glass under high electric field must be avoided through a careful choice of the substrate. These restrictions severely limit the use of MSGC in high-energy physics, and solutions using a preamplification stage have been proposed [1]. In neutron instrumentation, the detection conditions are simpler for the following reasons: counting rates are moderate, there is no constraint on the thickness or the density of the substrate, and the primary charge produced by the interaction of a neutron in the gas is two or three orders of magnitude higher than with minimum ionizing particles.