Nabin Rijal
Measurement of deuteron-induced reaction on mass-7 using ANASEN & it's implication in the Big Bang Nucleosynthesis
The multi-years WMAP + Planck results tightly constrain the baryonic density in the Universe with the highest precision ever achieved, resulting in more constrains in the light element abundance predicted by Standard Big Bang Nucleosynthesis (SBBN). The observed amount of all other light elements H, D, 3He, 4He agrees well with SBBN calculations, but the 7Li abundance is observed to be 3-4 times less than the calculated amount. This is referred to as the 'Lithium problem'. We performed  studies of the 7Be+d reaction at energies relevant to SBBN.  This reaction could destroy a fraction of the mass-7 nuclei under the conditions of the Big Bang and could offer an explanation for the observed deviation from the prediction of SBBN. We investigated the 7Be+d reaction at SBBN energies using a radioactive 7Be beam and a deuterium gas target, stopping the beam in the target gas inside the ANASEN detector at Florida State University. The ANASEN detector is an active gas target detector system which tracks the charged particles using a position sensitive proportional counter with position sensitive double sided silicon detectors all backed up by Cesium Iodide (CsI) detectors. The experiment measured a continuous excitation function by slowing down the beam in the target gas down to zero energy by using a single beam energy. Our experimental set-up provides a high detection efficiency for all relevant reaction channels focusing on the lowest energies, relevant to the BBN. Results of this experiment will be presented along with experimental techniques.