Compared study of mechanisms of the reactions ⁷Li (d,2α) n at 0.175 MeV and t(⁶Li, 2α) n between 0.7 and 1.3 MeV

This work allowed us to make a quantitative study of the continuous spectra of the alpha particles of the reactions d + ⁷Li and ⁶Li + t, with 175 keV as energy of the deutons, and 0.7 to 1.3 MeV as energy of ⁶Li. We could thus give the mechanisms of these reactions, and the percentages of each mechanism compared to the whole. For d + ⁷Li and ⁶Li + t, we have concluded that the fundamental level and the first excited state of ⁵He are involved. The experimental and theoretical results are in good agreement by taking for this last level an excitation energy of 1.6 MeV and a width of 6 MeV. We noticed the absence of the asymmetric burst peak in the d + ⁷Li reaction, while it was apparent in the ⁶Li + t reaction. This leads us to confirm M. Demeur's ideas on the formation of nuclear molecules. According to M. Demeur, there can only be a nuclear molecule, and thus a break-up of the type described, if there are at least two stable centers, just like a chemical molecule. We give here a table of some of the reactions studied up to now by the group of L. Marquez, reactions which are likely to present a splitting that we will call now 'molecular'. Thus, the nuclear 'molecules' would be constituted like chemical molecules with stable centers and particles which ensure the connection between these centers. The probability of presence of these particles, always by analogy with chemistry, is greater in the vicinity of the centers than in the intermediate region. It thus happens that these particles react between them, in the vicinity of one of the centers, which takes part in the reaction; the other center, too far, does not intervene practically. It is then an explosion of dissymmetrical nature like that observed for ⁶Li + t, ⁶Li + ⁶Li and ⁶Li + ¹⁰B. (O.M.).