KeV Astrophysics with GeV Beams; Blazing a New Trail on the Summit of Nuclear Astrophysics

摘要

GeV beams of light ions and electrons are used for creating a high flux of real and virtual photons, with which some problems in Nuclear Astrophysics are studied. GeV ~8B beams are used to study the Coulomb dissociation of ~8B and thus the ~7Be(p,γ)~8B reaction. This reaction is one of the major source of uncertainties in estimating the ~8B solar neutrino flux and a critical input for calculating the ~8B solar neutrino flux. The Coulomb dissociation of ~8B appears to provide a viable method for measuring the ~7Be(p,γ)~8B reaction rate, with a weighted average of the RIKEN1, RIKEN2, GSI1 and MSU published results of S_(17)(0) = 18.9 +- 1.0 eV-b. This result, however, does not include a theoretical error estimated to be +-10%. GeV electron beams on the other hand, are used to create a high flux of real and virtual photons at TUNL-HIGS and MIT-Bates, respectively, and we discuss two new proposals to study the ~(12)C(α,γ)~(16)O reaction with real and virtual photons. The ~(12)C(α,γ)~(16)O reaction is essential for understanding Type II and Type Ia supernova. It is concluded that virtual and real photons produced by GeV light ions and electron beams are useful for studying some problems in Nuclear Astrophysics.