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

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) are described. The IC undergoing testing is attached to a DUT (device under test) board, which is enclosed in a metal container (see left-hand side of Fig. 1). The container is then lowered to the cobalt 60 radiation source located at the bottom of a 15-ft-deep pool (see Fig. 2) filled to the top with water. The gamma-ray radiation test setup is schematically shown in Fig. 3. 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 functional test of the IC. The software design and the radiation testing procedure are discussed in detail.