E1 and E2 cross sections of the ~(12)C(α,γ)~(16)Oreaction at E_(eff) ～ 1.2 MeV using pulsed a beams

摘要

We have measured the γ-ray angular distribution of the ~(12)C(α,γ)~(16)O reaction at the 3.2 MV Pelletron accelerator laboratory at Tokyo Institute of Technology to accurately determine the E1 and E2 cross sections. In this experiment, we used high efficiency anti-Compton NaI(Tl) spectrometers to detect a γ-ray from the reaction with a large S/N ratio, intense pulsed α-beams to discriminate true events from background events due to neutrons from ~(13)C(α,n)~(16)O reaction with a time-of-flight method, and the monitoring system of target thickness. We succeeded in removing a background events due to neutrons and clearly detected the γ-ray from the ~(12)C(α,γ)~(16)O reaction with high statistics.