Precise measurement of the cross section of He-3(He-3,2p)He-4 by using He-3 doubly charged beam

The fusion cross section of He-3(He-3,2p)He-4 at a center of mass energy of 30-50 keV has been measured by using a helium-3 doubly ionized beam at a low-energy high current accelerator facility OCEAN. Free from molecular interference in the beam, the measurement determines the astrophysical S factor with better statistical and systematic errors than previous data. By using singly and doubly charged helium-3 ions, the facility envisages to provide the data from high-energy to Gamow energy regions.