Neutron Spectra from the 3H(7Li, 2n)2α Reaction

Abstract

A time-of-flight spectrometer with two scintillation counters was used to look for n–n coincidences in the reaction 3H(7Li,8Begs)2n at 0° and at 117°. The mean incident energies of the Li ions were 14.6 and 22.7 MeV. No evidence for a n–n final state interaction peak was found, with the upper limit on the cross section being of the order of 10−26 cm2/sr2.The observed time difference spectra were compared with the following reaction models: (1) direct break-up; (2) sequential decay via the channel, 4He + 6He* → 2α + 2n; and (3) independent successive emission of the two neutrons from a compound nucleus. This latter reaction mechanism is favored by the data.