Delayed neutrons and high-energy γ-rays from decay of 87Br

Delayed neutrons and high-energy γ-rays following decay of ⁸⁷Br have been studied to characterize the β-decay to and the decay of neutron unbound levels in ⁸⁷Kr. The principal part of the neutron spectrum appears due to some 20–30 individual transitions and for seven of these, decay by γ-ray emission has been demonstrated. The β-strength function derived from these data and the decay scheme at lower energies is dominated by a broad resonance located near the neutron binding energy which can be identified with the main strength of a single-particle transition. The fluctuations in the reduced β-transition probabilities are found to be in accord with the Porter-Thomas distribution and the observed level density just above the neutron binding energy is consistent with the Gilbert and Cameron prediction after accounting for fluctuation in the β-decay transition probabilities.