Investigation Of He-6 Cluster Structures

The alpha+2n and t+t clustering of the He-6 ground state were investigated by means of the transfer reaction He-6(p,t)He-4 at 25 MeV/nucleon. The experiment was performed in inverse kinematics at GANIL with the SPEG spectrometer coupled to the MUST array. Experimental data for the transfer reaction were analyzed by a distorted wave Born approximation (DWBA) calculation, including the two neutrons and the triton transfer. The couplings to the He-6 -> He-4+2n breakup channels were taken into account with a polarization potential deduced from a coupled-discretized-continuum channels analysis of the He-6+H-1 elastic scattering measured at the same time. The influence on the calculations of the alpha+t exit potential and of the triton sequential transfer is discussed. The final calculation gives a spectroscopic factor close to one for the alpha+2n configuration as expected. The spectroscopic factor obtained for the t+t configuration is much smaller than the theoretical predictions.