Microstrip gas chambers on thin plastic supports

The authors describe the development of microstrip gas chambers manufactured on thin-foil plastic supports. They have used two supports, Kapton and Tedlar, that were suitable for microstrip chambers. Results are given for both materials. It was demonstrated that gaseous microstrip chambers with thin plastic supports can be operated at large proportional gains with good energy resolution for low rate 5.9-keV X-rays. A space-charge dominated gain drop appeared only at very high rates, close to 10⁶ s^-1-mm^-2. The long-term variations of gain of chambers exposed to constant radiation fluxes were studied. The measurements showed long-term time-dependent modifications (charging up), particularly for high-resistivity supports