Measurement of the ~(10)B( p,α_0)~7Be cross section from 5 keV to 1.5 MeV in a single experiment using the Trojan horse method

摘要

For the first time the astrophysical factor of the ~(10)B(p,α_0)~7Be reaction has been measured over a wide energy range, from 5 keV to 1.5 MeV, via the Trojan horse method (THM) applied to the quasifree ~2H(~(10)B ,α~7Be)n reaction. Therefore, the S(E) factor has been recast into absolute units by scaling in the energy range 200 keV-1.2 MeV to a recent measurement using the activation method, leading to a normalization uncertainty of 4%.AnR-matrix fit of theTHMdatawas performed, to parametrize the S factor, obtain spectroscopic information on the populated resonances, and compare with other recent experiments. Finally, a new determination of the screening potential U_e has been obtained, U_e= 240 ± 50 eV, with a much smaller error than our previous measurement.