Accession Number : AD0668329

Title :   THERMAL-NEUTRON FISSION OF 235U: IDENTIFICATION AND FRACTIONAL CHAIN YIELD OF 77GA,

Corporate Author : NAVAL RADIOLOGICAL DEFENSE LAB SAN FRANCISCO CA

Personal Author(s) : Wish, Leon

Report Date : 11 FEB 1968

Pagination or Media Count : 24

Abstract : The study of nuclear charge dispersion in the light-fission-product region from thermal-neutron irradiation of 235U was begun with measurements on mass chain 77. An ion exchange procedure was developed which rapidly separated Ga from its daughter products, Ge and As. Ga separations were made at various times after fission and the Ge daughter activities were isolated and measured. From these activities 77Ga and 78Ga were indirectly identified as fission products. The half-life of 77Ga was determined to be 17.1 plus or minus 1.5 sec and that of 78Ga was estimated to be about 4 sec. The branching ratio of 77Ga for formation of 77mGe and 77gGe was obtained from measurements of the 39-hr 77As activity at the time when the 54-sec 77mGe and the 11.3-hr 77gGe had each mostly decayed. Values obtained for decay to 77mGe and 77gGe are 0.88 plus or minus 0.02 and 0.12 plus or minus 0.02, respectively. The fractional cumulative yield of 77Ga was determined as 57.3 plus or minus 1.4 percent. (Author)

Descriptors :   *GALLIUM), (*URANIUM, FISSION), (*FISSION PRODUCTS, THERMAL NEUTRONS, RADIOACTIVE ISOTOPES, SEPARATION, ION EXCHANGE, FISSION PRODUCT ACTIVITY, DECAY SCHEMES, HALF LIFE.

Subject Categories : Nuclear Physics & Elementary Particle Physics
      Radioactiv, Radioactive Wastes & Fission Prod

Distribution Statement : APPROVED FOR PUBLIC RELEASE