New measurements of the mass of isotope 4H in reactions with a radioactive 6He beam and 6Li ions
Aleksandrov D. V. , Nikol'skii E. Yu. , Novatskii B. G., Stepanov D. N. , Bur'yan V., Kroga V. , Novak Ya.
The cross sections of the reaction D(6He, a) at £eHe = 19.3 MeV were measured for the first time. Two resonances were observed in the a particle spectrum. The resonances correspond to the ground and excited states of the nuclear-unstable isotope 4H that lie 2.0±0.3 MeV and 5.2±0.5 MeV above the 4H —>r + n dissociation threshold. It is assumed that the excited state of 4H has the configuration (d+ 2n) and the quantum characteristics 1 + . The nuclear instability of 4H (2.3±0.3 MeV) is confirmed by measurements of the reaction 6Li(6Li,8B) at the energies Eeu = 85 and 93 MeV. As a result, a new value is obtained for the 4H mass defect: 25.3 + 0.3 MeV. © 1995