Speaker
Dr
Sunghoon (Tony) Ahn
(JINA/NSCL)
Description
(α,xn) reactions have been identified as the main production mechanism of Z=38-47 abundances in neutrino driven winds during core-collapse supernovae scenario. Recent sensitivity studies showed that uncertainties in (α,xn) reaction rates directly affect calculated abundances in the neutrinodriven wind models with an impact that is comparable to that from astrophysical uncertainties. Current reaction rate uncertainties are relatively large since there is almost no acknowledgement of experimental data for (α,xn) cross sections involved in the nucleosynthesis calculation.
We have developed the Heavy ion Accelerated Beam induced (Alpha,Neutron) Emission Ratio Observer (HabaNERO) for the measurement of relevant (α,xn) reaction cross sections in the theoretical study, including 75Ga(α,xn). The HabaNERO is a neutron long counter system which consists of 44 BF3 and 36 3He gas-filled proportional tubes oriented in rings along the beam axis embedded in a polyethylene matrix. The configuration of the tubes in the matrix was optimized to obtain a high average neutron detection efficiency as constant as possible in the neutron range En = 0.1-19.5 MeV that corresponds to the neutron energies of interest.
We have performed the detector commissioning using mono-energetic neutron beams at Edward Accelerator Laboratory, Ohio University, as well as a 75Ga(α,xn) cross section measurement at the National Superconducting Cyclotron Laboratory. We will present the detector development and the first experiment of (α,xn) reaction in inverse kinematics with 75Ga radioactive ion beams and our new detector.
Primary author
Dr
Sunghoon (Tony) Ahn
(JINA/NSCL)