N14(n,d)C13,N14(n,t)C12, andN15(n,d)C14nearEn=14MeV

Abstract
A triple-coincidence counter telescope consisting of two thin silicon surface-barrier dEdx detectors (114 μ total thickness) and a CsI E detector was used with a pulse-multiplier particle-discrimination system to detect the charged particles emanating from nuclear reactions induced by 14.1- or 14.8-MeV neutrons. Angular distributions of the outgoing charged particles from the ground-state transitions of N14(n,d)C13 and N14(n,t)C12 were measured out to a center-of-mass angle of 100° for 14.1-MeV incident neutrons. The (n,d) distribution was fitted with two l=1 theoretical curves calculated from the Butler and distorted-wave Born-approximation (DWBA) theories. The (n,t) results were fitted by two l=2 curves calculated from the double-stripping theory of Newns and the diffraction theory of Dar, and were compared to previous results obtained for C12(He3,p)N14. Charged particles corresponding to the excited-state transitions N14(n,d)C13  (Ex=3.68 MeV) and N14(n,t)C12  (Ex=4.43 MeV) were detected at forward angles. Angular distributions for the N15(n,d)C14  (Ex=0) reaction were measured out to 60 degrees for En=14.1 and 14.8 MeV. The 14.8-MeV data were fitted with Butler and DWBA curves for l=1, but the 14.1-MeV data were inconsistent with a pure-direct-reaction interpretation. The results agree with previous measurements on the inverse C14(d,n)N15 reaction, and indicate that a compound-nucleus mechanism contributes strongly near 14.9 MeV of excitation in the N16 compound nucleus. Absolute reduced widths θ2 and spectroscopic factors C2S were extracted from the fits to the N14,15(n,d)  (Ex=0) reactions.