Recoiled Proton Tagged Knockout Reaction for ~8He

An experiment for knockout reaction induced by 8He beam at 82.5 MeV/nucleon on CH2 and C targets was carried out. The 6He and 4He core fragments at forward angles and the recoiled protons at large angles were detected coincidently. From this exclusive measurement the valence nucleon knockout mechanism and the core knockout mechanism are separated, which can be applied to the exclusive spectroscopic study on the structure of exotic nuclei.     

Experimental Study of Two-Neutron Correlation in ~8He~+

A neutron detector array was used in a breakup reaction experiment at RIKEN with an 82.5 MeV/u 8He beam impinging on the CH2 and C targets. The array was calibrated using the cosmic ray, the γ ray from the 6 He+Pb reaction and the mono-energetic neutrons from the 7Li(p, n)7Be(g.s.+0.43 MeV) reaction. The position resolution, timing resolution and neutron detection efficiency were obtained accordingly. Cross-talk rejection conditions were developed based on analysis of the data taken from the 7Li(p, n) 7Be(g.s.+0.43 MeV) test experiment, and finally a preliminary two-neutron correlation function for the 8 He breakup reaction was investigated.     

Knockout Reaction Mechanism for ~6He~+

A knockout reaction experiment was carried out by using the 6He beam at 82.5 MeV/nucleon impinging on CH2 and C targets. The a core fragments at forward angles were detected in coincidence with the recoiled protons at larger angles. From this exclusive measurement the valence nucleon knockout mechanism and the core knockout mechanism are separated. This study provides a basis for the exclusive spectroscopic investigation of the exotic nuclei.