Beam-energy dependence and updated test of the Trojan-horse nucleus invariance via a measurement of the 2H(d, p)3H reaction at low energies

The H-2(d,p)H-3 bare nucleus astrophysical S(E) factor has been measured indirectly at energies from about 500 keV down to several keV by means of the Trojan-horse method applied to the H-2(Li-6, pt)He-4 quasifree reaction induced at 11 MeV. The obtained results are compared with direct data as well as with previous indirect investigation of the same binary reactions. It shows that the precision of S(E) data in the low-energy range extracted via the same Trojan-horse nucleus [Li-6 = (d circle plus a)] increases while the incident energy of the virtual binary process approaches the zero-quasi-free-energy point. The very good agreement between data extracted from different Trojan-horse nuclei [Li-6 = (d circle plus alpha vs He-3 = (d circle plus p)] gives a strong updated test for the independence of the binary indirect cross section on the chosen Trojan-horse nucleus at low energies.