L2-SUBSHELL YIELD MEASUREMENTS IN PU240 U236 AND U234

The fluorescence, Auger, and Coster-Kronig yields of the L2 subshells in Pu240, U236, and U234 have been determined from measurements on L x-rays emitted following α decay of Cm244, Pu240, and Pu238. The techniques employed include α-L x-ray coincidence counting using a silicon detector and NaI(Tl) crystal, proportional-counter spectrometry and in the case of Pu238, the use of a curved-crystal spectrograph. The following results were obtained: Pu240, ω2=0.466±0.023, a2=0.11±0.08, f23=0.42±0.08; U236, ω2=0.535±0.042, a2=0.09±0.11, f23=0.37±0.07; U234, ω2=0.497±0.035, a2=0.07±0.07, f23=0.43±0.06. The measured fluorescence yields show close agreement with those calculated on a semiempirical basis by Listengarten, but the Auger and Coster-Kronig yields are, respectively, much smaller and much larger than predicted. © 1968 The American Physical Society.