IV. Coincidence measurements on the ?-decay of boron 12

Abstract

A study of β-γ and γ-γ coincidences associated with the β-decay of ¹²B has been made in order to analyse the β-spectrum. It is concluded that, relative to the transition to the ground state of ^l2C, (1·7 ± 0·4)% of the β-transitions are to the 4·43 mev excited state, and ≤(0·0 ± 0·2)% to the 7·66 mev state. A technique of comparison between ¹²B and ⁸Li was used which incidentally gave a new upper limit of ≤(0·2±0·1)% for γ-radiation following the ⁸Li decay.