Cross-section measurement of $^7Be + d$ and $^7Li + d$ with ANASEN* and its implication in the Big Bang Nucleosynthesis.

Astrophysically observed $^7Li$ is $3 - 4$ times less than predicted amount by current models of Standard Big Bang Nucleosynthesis (SBBN). The nuclear reaction $^7Be + d $ at energies relevant to SBBN, has been discussed as a possible means to destroy mass-7 nuclei. We investigated the $^7Be + d$ and it's mirror nuclear reaction $^7Li + d$ at SBBN energies using a radioactive $^7Be$ and stable $^7Li$ beam both in deuterium gas target inside ANASEN at Florida State University. ANASEN is an active target detector system which tracks the charged particles using a position sensitive proportional counter and 24-SX3 and 4-QQQ position sensitive Silicon detectors, all backed up by CsI detectors. ANASEN has wide angular coverage. The experiment measures a continuous excitation function by slowing down the beam in the target gas down to zero energy by using a single beam energy. Our set-up provides a high detection efficiency for all relevant reaction channels including $(d,p), (d,\alpha)$ and/or direct breakup that can destroy mass-7 nuclei in contrast to previous measurements. The preliminary results of these experiments along with details of ANASEN detector will be presented. *ANASEN: Array for Nuclear Astrophysics and Structure with Exotic Nuclei.