Beta-delayed neutron emission is a dominant decay mode for the very neutron-rich nuclei. With the opportunities offered by new generation radioactive beam facilities, we can perform experiments with a larger and more exotic pool of isotopes. This enabled us to revisit the conventional views on the fundamentals of beta delayed neutron emission. However, new data and improved models are necessary because of the critical role of beta-delayed neutron emission for astrophysics (r-process) and reactor physics. Using experimental results obtained for very exotic isotopes with neutron arrays such as VANDLE or BRIKEN, I will show how these recent measurements enabled us to improve the understanding of this process. One of the central questions is if and how the nuclear structure effects may influence beta delayed neutron emission. The results on competition of between 1n and 2n emission will be presented and explained using a combination of shell-model and statistical model description. I will also show examples where the assumption of statistical neutron emission from the compound nucleus may be broken.
This research is supported U.S. Department of Energy, National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Award No. DE-NA0002934 and DE-NA0003899,and DOE Office of Science Award No. DE-FG02- 96ER4093.