DIRECT CHARGE-EXCHANGE VERSUS SEQUENTIAL NUCLEON TRANSFERS IN THE C-14(LI-6,HE-6)N-14 REACTION AT 93 MEV

The C-14(Li-6,He-6)N-14 reaction was investigated at a Li-6 ion energy of 93 MeV. The angular distributions for several natural and unnatura l parity states of the N-14 nucleus were compared with the DWBA and Co upled Reaction Channels (CRC) calculations assuming direct charge exch ange and two-step sequential nucleon transfers. It was shown that the direct charge-exchange mechanism dominates for the transitions to the ground and excited (E-x = 3.95 MeV) 1(+) states of the N-14 nucleus up to angles of 50 degrees-70 degrees. The sequential nucleon transfers must be taken into account at larger angles for these states and in th e full angular range for the other states (2.31 MeV (0(+),T = 1), 5.11 MeV (2(-)), 5.69 MeV (1(-)) + 5.83 MeV (3(-)), 7.03 MeV (2(+)) and 8. 49 MeV (4(-))). (C) 1998 Elsevier Science B.V.