Disintegration ofLa135and Confirmatory Experiments onNd147

Abstract

The disintegrations of La 135 , Ba 135 " 1 , and Nd 147 have been studied with the help of magnetic spectrometers and scintillation counters. La 135 decays almost entirely by electron capture. The half-life has been found to be 19.8=h0.2 hr. Electron capture to the ground state takes place in 95-97% of all disintegrations. Gammarays of energies 104, 218, 265, 295, 367,481, 588, 642, 862 kev have been found. There is a very weak positron spectrum. The internal-conversion coefficient of the line at 481 kev has been measured. The value 0^ = 0.0130 indicates an Ml transition. The line at 862 kev has aK-2.5XlO~3. The disintegration scheme is discussed. The internal-conversion coefficient of the line at 265 kev from Ba 135w has been found to be aK~S.S2dtz0.2. The spectrum of Nd 147 has been reinvestigated, confirming the scheme of Hans, Saraf, and Mandeville. The internal-conversion coefficient for the line at 92 kev has been found to be 1.52 ±0.05.

Symmetric and Asymmetric Fission

“…1. There is complete agreement in the decay schemes as proposed by Hans et al 8 and Mitchell 6 on the one hand, and Cork 7 on the other hand, except eter for each curve to fit the small steep regions on each side of mass number %Ao. The qualitative agreement [ Fig.…”