### ISOMERIC LEVEL IN Pb$sup 205$ FORMED IN THE DECAY OF Bi$sup 20$sup 5$ISOMERIC LEVEL IN Pb$sup 205$FORMED IN THE DECAY OF Bi$sup 20$sup 5$

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 Author Vegors, S. H. (Jr.) ♦ Heath, R. L. Source United States Department of Energy Office of Scientific and Technical Information Content type Text Language English
 Subject Keyword PHYSICS ♦ BISMUTH 205 ♦ BRANCHING RATIO ♦ CAPTURE ♦ COINCIDENCE METHODS ♦ DECAY ♦ EFFICIENCY ♦ ELECTRONS ♦ ENERGY LEVELS ♦ GAMMA RADIATION ♦ HALF-LIFE ♦ INTERNAL CONVERSION ♦ ISOMERS ♦ LEAD 205 ♦ MEASURED VALUES ♦ NUCLEAR MODELS Abstract An activity of 4.8-msec half-life which is assigned to Pb/sup 205m/ has been observed in the electron capture decay of 14.5-day Bi/sup 205/. This isomeric level decays with the emission of 987.8, 703.3, and 284.4-kev gamma rays with relative transition intensities of 100, 10, and 10. No other gamma rays of energy greater than 10 kev were observed in the decay of this isomer. The 284.4- and 703.3-kev gamma raya are in coincidence but neither is in coincidence with the 987.8-kev transition. This evidence suggests that the 987.8-kev level de- excites directly to the ground state by the emission of a 284.4, 703.3 kev cascade with a 987.8-kev crossover. There is some evidence (not conclusive) that the 987.8-kev level itself may not be isomeric but that it may be fed entirely by a highly oonverted low-energy transition (<100 kev) from an isomeric level. (auth) ISSN 0031899X Educational Use Research Learning Resource Type Article Publisher Date 1960-04-15 Publisher Department Phillips Petroleum Co., Idaho Falls, Idaho Journal Physical Review Volume Number 118 Organization Phillips Petroleum Co., Idaho Falls, Idaho