Direct measurement of 4He(12C, 16O)γ reaction cross section around Ecm = 2.4 MeV at KUTL

A direct measurement of 4 He( 12 C, 16 O) γ reaction cross section is in progress at Kyushu University tandem laboratory (KUTL). A 12 C beam is incident on a windowless 4 He gas target. The 16 O recoils are separated from the beam by a recoil mass separator and are detected by a Si-detector. In order to increase beam intensity, target thickness and detection efficiency, original instruments and methods have been newly developed. To reduce background (BG), a beam from the tandem accelerator was pulsed. Recently a long-time chopper was developed to further separate the reaction recoils and BG, and a test measurement of 4 He( 12 C, 16 O) γ reaction cross section at E cm = 2.4 MeV was made.