Investigation of the Outgoing Tritons Angular Distribution in the ~9Be(n, t_1γ)~7Li~* Reaction at 14.9 MeV by the Line Shape Analysis of the 0.4776-MeV Gamma Transition

摘要

Doppler broadening line shapes of 0.4776-MeV gamma transition of ~7Li~* populated in the ~9Be(n,t_1 γ) reaction at 14.9 MeV have been analyzed at 40-, 55-, and 90-deg detector positions in respect to the beam axis for the evaluation of the angular distribution W(θ) of outgoing tritons (t_1) after the population of first ~7Li excited state. A nonsymmetrical shape of the W(θ) dependence with the Legendre polynomial coefficients A_1 = 0.31 +- 0.06 and A_2 = 0.23 +- 0.06 has been found. That fact does not support the belief in the simple nuclear reaction mechanism through the single isolated level of ~(10)Be compound. Obtained data are compared with other available experimental results.