  We investigate the decay of 87Br, 88Br and 94Rb using total absorption
gamma-ray spectroscopy. These important fission products are beta-delayed
neutron emitters. Our data show considerable gamma-intensity, so far unobserved
in high-resolution gamma-ray spectroscopy, from states at high excitation
energy. We also find significant differences with the beta intensity that can
be deduced from existing measurements of the beta spectrum. We evaluate the
impact of the present data on reactor decay heat using summation calculations.
Although the effect is relatively small it helps to reduce the discrepancy
between calculations and integral measurements of the photon component for 235U
fission at cooling times in the range 1 to 100 s. We also use summation
calculations to evaluate the impact of present data on reactor antineutrino
spectra. We find a significant effect at antineutrino energies in the range of
5 to 9 MeV. In addition, we observe an unexpected strong probability for gamma
emission from neutron unbound states populated in the daughter nucleus. The
gamma branching is compared to Hauser-Feshbach calculations which allow one to
explain the large value for bromine isotopes as due to nuclear structure.
However the branching for 94Rb, although much smaller, hints of the need to
increase the radiative width by one order-of-magnitude. This leads to a similar
increase in the calculated (n,gamma) cross section for this very neutron-rich
nucleus with a potential impact on r-process abundance calculations.
