The effects of gamma radiation on JFET and bipolar transistors with application to the SSC

Design of a low-noise, low-power, high-speed, and radiation-hardened charge sensitive preamplifier for the Superconducting Super Collider (SSC) has prompted an investigation of front-end devices. Several state-of-the-art JFET and bipolar transistors along with devices from a semi-custom analog integrated circuit process were characterized in both a normal and low-current operation region. In these regions the JFETs were characterized for noise, ac, and dc parameters before and after exposure to gamma radiation. The bipolar devices were characterized for ac and dc parameters before and after exposure to gamma radiation. Analysis of the transistors and data from these regions are presented along with a highlight of radiation effects on these devices. Also presented is the design and implementation of a noise measurement system for JFET devices.