A Laboratory Quality Charge Sensitive Amplifier Suitable for Space Applications

Abstract

The amplifier described is designed for use with uncooled silicon nuclear particle detectors connonly used in space instruments. The charge sensitive preamplifier and two-stage shaping amplifier provides the performance of a laboratory quality instrument while simultaneously satisfying the stringent requirements imposed upon flight hardware. Double differentiation-double integration (DDDI) pulse shaping with pole-zero cancellation of the preamplifier decay time constant was selected on the basis of simplicity, adequate noise performance, and stabillity at high count rates. The components used in the design are compatible with hybrid microcircuit fabrication. Noise performance at 1 ¿sec DDDI time constants was measured to be 1.8 KeV + 47 eV/pf FWHM (Silicon) for an amplifier consuming 100 mW. The operating temperature range is approximately -40° to +80°C. Further results of an extensive testing program are reported.