Beta-decay measurement of $^{46}$Cr

For the rapid proton capture process ($\it{rp}$-process) in X-ray bursts and the core-collapse stage of supernovae, proton-rich $\it{pf}$-shell nuclei far from the line of stability play important roles. Studies of the feeding ratios and half-lives of the $\beta$ and electron capture decays of these proton-rich $\it{pf}$-shell nuclei are of great astrophysical interest not only for nucleo synthesis but also for Fermi and Gamow-Teller transition study. The experiment to measure the half life of $\beta$ decay of $^{46}$Cr was performed using the low-energy RI beam separator (CRIB) of the Center for Nuclear Study (CNS), University of Tokyo. The $^{46}$Cr particles were produced by the $^{36}$Ar + $^{12}$C fusion reaction. A natural C foil of 0.56 mg/cm$^{2}$ was installed as the primary target. The $^{36}$Ar primary beam was accelerated up to 3.6 MeV/nucleon by the RIKEN AVF cyclotron. A double sided Si strip detector (DSSD) of 500-$\mu$m thickness was used as a $\beta$-ray detector. A Si detector of 1.5-mm thickness was placed just behind the DSSD for a $\beta$-ray detector. To measure $\beta$-delayed $\gamma$ rays, 3 clover and 1 coaxial Ge detectors were set around the target chamber. The beam was pulsed to measure the half life of the $\beta$ decay of $^{46}$Cr. The $\beta$-delayed $\gamma$ ray of $^{46}$Cr was observed in this experiment. The experimental result will be discussed.