A microdischarge-based radiation detector utilizing stacked electrode arrays in a TO-5 package

This paper describes miniature discharge-based beta/gamma radiation detectors that use arrayed electrode structures to demonstrate a scalable path for increasing detection efficiency. The discharges are also used for wireless signaling. The device uses an in-package assembly scheme of stainless steel electrodes and a glass spacer structure within a TO-5 package. It is manufactured by leveraging commercial micromachining technologies e.g., photochemical etching of the electrodes and ultrasonic machining of the spacer structure. The detector diameter and height are 9 mm and 9.6 mm, respectively, and it weighs 1.01 g. The device performance has been characterized using a P-10 fill-gas near 710 Torr, with a 99 μCi ¹³⁷Cs source (which is a beta and gamma emitter). The normalized gamma sensitivity is estimated to be 0.023 cps/mR/hr/mm³ as measured with the biasing arrangement described in the paper. Portable powering modules developed for these detectors are also presented. Rapid wireless transmissions with durations on the order of tens of ns have been measured.