Accession Number:

AD0872977

Title:

Radiation-Induced Second Breakdown.

Descriptive Note:

Technical rept. Aug 69-Feb 70,

Corporate Author:

HUGHES AIRCRAFT CO FULLERTON CA

Personal Author(s):

• Carr, E. A.
• Binder, D.

Report Date:

1970-07-01

Pagination or Media Count:

51.0

Abstract:

Six transistor types used in systems were tested for radiation-induced second breakdown caused by flash X-ray pulses of 10 to the 12th power rad Sis. The data were taken with the electron beam of a 2 MeV Febetron. An electron-gamma correlation was demonstrated, within experimental error, by producing equal secondary photocurrents for equal doses of electrons and gammas. Extraneous effects from scattered electrons were minimized by the use of co-limation. Most of the data were taken by nondestructive methods. For two of the transistor types, destructive tests were required for unambiguous results. Five of the six transistor types were not susceptible to radiation-induced second breakdown at voltages less than 50 percent of the rated voltage. One of the transistor types, however, was found to be vulnerable at 15 percent of the rated voltage. The effect is very dependent on output loading since currents on the order of amperes are required to induce second breakdown. A model is presented which indicates that input loading and bias have a minimal effect. Although protection against the catastrophic failure of circuits is usually afforded by current limiting, a circuit is discussed where a low-impedance path presents a possible problem. Author

Descriptors:

• *TRANSISTORS
• DAMAGE
• PHOTOELECTRIC EFFECT
• FAILURE(ELECTRONICS)
• FAILURE(ELECTRONICS)

Subject Categories:

• Electrical and Electronic Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE