Internal bremsstrahlung spectrum of 139Ce.

Abstract

The internal bremsstrahlung spectrum which accompanies the electron capture decay of {sup 139}Ce to the first excited state of {sup 139}La has been measured in coincidence with the nuclear gamma ray which deexcites that state. The measured intensity above 42 keV is found to be (1.070{plus_minus}0.024) times that predicted by the recent calculations of Suri{acute c} {ital et} {ital al}. The {ital Q}{sub EC} value is found to be 264.6{plus_minus}2.0 keV. {copyright} {ital 1996 The American Physical Society.}