Nuclear radiation test of a D flip-flop IC using a single-board microcomputer

A description is presented of the design of a microcomputer-controlled electronic circuit and its use in evaluating the effects of nuclear radiation on a 4013 CMOS D flip-flop (FF) integrated circuit (IC). The IC undergoing testing is attached to a device-under-test board, which is enclosed in a metal container. The container is then lowered to the cobalt 60 radiation source located at the bottom of a 15-ft-deep pool filled with water. The gamma-ray radiation test setup is schematically shown. The in-source test board containing the D-FF IC is attached to an 8085-based single-board microcomputer, SDK-85, by a 30-ft multiconductor cable. Doses of gamma-ray radiation from the cobalt 60 are applied in steps at increasing quantities until the D-FF IC, which is tested between doses, begins to malfunction. The leakage current and the propagation delay time are measured between doses. An 8085 assembly language program is used for the functional test of the IC. The software design and the radiation testing procedure are discussed in detail.