Measuring Multi-Neutron Emission in Neutron-Rich Nuclei; First Results from the BRIKEN Collaboration

Exploring the beta decay of extremely neutron rich nuclei gives insight into nuclear structure far from stability and gives improved inputs into r process calculations that inform the production of the elements in the universe. The BRIKEN Collaboration has finished a commissioning run and two experimental runs at RIKEN using the BigRIPS separator. The BRIKEN detector setup is a collection of 140+ 3He tubes along with ion-implant detectors such as the silicon stack arrays of AIDA and WAS3ABI and a YSO scintillator implant detector. Over 250 neutron-rich isotopes were measured and around 45 new half lives and 165 new single neutron emission probabilities are expected to be measured. In addition at least 10 nonzero two neutron emission probabilities in the Nickel 78 region were measured. We will present an overview of the BRIKEN detector, the setup at RIKEN, and a brief overview of the analysis technique used to extract multi-neutron emission probabilities. First results on some two neutron emission probabilities will be presented.