Monolithic, radiation hard charge sensitive preamplifier using diffused N-channel junction field effect transistors

A monolithic preamplifier entirely based on epitaxial channel, diffused-gate N-JFET has been designed and thoroughly investigated by means of SPICE simulation and breadboard implementation. Performance, tolerances, and matching of the devices are remarkably good, and the excess noise can be reduced in future runs. A preamplifier has been wired using monolithic JFET and is working according to predictions. The preamplifier is intended for applications with ionization chamber calorimeters in the SSC (Superconducting Super Collider) environment at processing times of about 50 ns.<>