Nuclear Structure of $8B$ Studied by Proton Resonance Scatterings on $7Be$

A new measurement of the proton resonance scattering on $7Be$ was performed up to the excitation energy of 6.8 MeV using the low‐energy RI beam facility CRIB (CNS Radioactive Ion Beam separator) at the Center for Nuclear Study (CNS) of the University of Tokyo. The excitation function of $8B$ above 3.5 MeV was successfully measured for the first time, providing important information about the reaction rate of $7Be(p,γ)8B,$ which is the key reaction in the solar $8B$ neutrino production. For more intensive experimental studies with RI beams, the development of a cryogenic gas target system is ongoing at CNS. In this paper a preliminary result of the $7Be$ experiment and the present status of the development of the target system are presented.