Experimental study of the t+t structure in 6He

The triton fragments produced in the reaction of 25 MeV/u 6He on 9Be target were detected by a set of telescopes. Energy spectra at five angles and the angular differential cross sections for the direct breakup components were obtained. Serber model calculation was carried out which reproduces well the experimental distribution, in agreement with the assumption of the direct breakup mechanism. Fermi model calculation was also applied to estimate the contribution of the reaction phase space. Subtraction of this contribution from the experimental data indicates that the t + t configuration takes about 1/3 of the total probability in the initial state of 6He, whereas the configuration of 4He core plus valence neutrons takes another 2/3 of the total probability. (authors)