Radiative capture of orbital electrons in the decay ofBe7

Abstract

The higher energy portion of the inner bremsstrahlung spectrum accompanying the allowed orbital electron capture transition in /sup 7/Be to the ground state of /sup 7/Li was measured with a single channel NaI(Tl) scintillation spectrometer. Correction for the pileup spectrum due to the 478 keV nuclear ..gamma.. rays arising from the deexcitation of the first excited state in /sup 7/Li was performed by numerical integration. The measured pulse-height distribution of the inner bremsstrahlung photons was corrected for detector response following the procedures of Liden and Starfelt and Palmer and Laslett. For energies higher than 560 keV the number of 1S + 2S bremsstrahlung photons emitted per ground state EC decay of /sup 7/Be was determined to be (6.31 +- 0.38) x 10/sup -5/. Corresponding theoretical values are 6.46 x 10/sup -5/, deduced from Martin-Glauber theory, and 6.45 x 10/sup -5/, deduced from the improved calculations of Intemann. The present result is in good agreement with the theoretical predictions. The decay energy of /sup 7/Be was determined to be 857 x 14 in agreement with the accepted atomic mass difference.