Bare nucleus S(E) factor of the 2H(d,p)3H and 2H(d,n)3He reactions via the Trojan Horse Method

The Trojan Horse Method was applied for the first time to the 2H(d,p)3H and 2H(d,n)3He reactions by measuring the 2H(3He,p3H)1H and 2H(3He,n3He)1H processes in quasi free kinematics. The 3He+d experiment was performed at 18 MeV, corresponding the a d-d energy range from 1.5 MeV down to 2 keV. This range overlaps with the relevant region for Standard Big Bang Nucleosynthesis as well as with the thermal energies of future fusion reactors and deuterium burning in the Pre Main Sequence phase of stellar evolution. This is the first pioneering experiment in quasi free regime where the charged spectator is detected. Both the energy dependence and the absolute value of the bare nucleus S(E) factors have been extracted for the first time. They deviate by more than 15% from available direct data with new S(0) values of 57.4±1.8 MeVb for 3H+p and 60.1±1.9 MeVb for 3He+n. None of the existing fitting curves is able to provide the correct slope of the new data in the full range, thus calling for a revision of the theoretical description. This has consequences in the calculation of the reaction rates with more than a 25% increase at the temperatures of future fusion reactors.