Accession Number : AD0286651

Title :   NUCLEAR TIMING

Corporate Author : ARMY RESEARCH OFFICE WASHINGTON D C

Personal Author(s) : COMYN,RAYMOND H. ; APSTEIN,MAURICE

Report Date : DEC 1962

Pagination or Media Count : 1

Abstract : A timer which operates on nuclear emission is eing developed for ordnance use. It consists of four parts: a radio-active source which emits alpha particles at a predictable average rate;A DETECTOR TO CONVERT THE NUCLEAR PULSES I TO EL CTRICAL PULSES; AN AMPLIFIER AND DISCRIMINATOR TO AMPLIFY THE PULSES AND SEPARATE THEM FROM ELECTRICAL NOISE; AND A BINARY SYSTEM TO COUNT THE PULSES AND INDICATE WHEN A DEFINITE CUMULATIVE OUTPUT HAS BEE ATTAINED AT THE END OF THE PREDETERMINED TIME PERIOD. Americium 241 presently is used as the alpha source. It is readily obtained, has a half life of 475 years, and its low level gamma ra iation can be shielded easily. Plutonium 239 has similar characteristics except for a half life of 24,100 years. Its use is recommended when long term storage stability is required. Silicon p-n diodes are used as detectors. These are small and operate on low voltage power supplies. Since they do not respond readily to beta, gamma, or cosmic radiation, the timer will not be influenced by extraneous radiation. (Author)

Descriptors :   *TIME INTERVAL COUNTERS, ALPHA PARTICLES, AMERICIUM, AMPLIFIERS, CIRCUITS, DETECTORS, DIODES, DISCRIMINATORS, GEIGER COUNTERS, GOLD, PLUTONIUM, PROPORTIONAL COUNTERS, PROTON COUNTERS, RADIOACTIVE ISOTOPES, SCINTILLATION COUNTERS, SILICON, SOLID STATE PHYSICS, TIMING CIRCUITS

Distribution Statement : APPROVED FOR PUBLIC RELEASE