Lifetimes in (sup 15)N from gamma-ray line shapes produced in the (sup 14)N(thermal n, gamma) reaction

摘要

Mean lifetimes of bound levels in (sup 15)N were inferred from the primary (gamma)-ray-induced Doppler broadening (GRID) of secondary (gamma) rays in the thermal-neutron capture reaction (sup 14)N(n,(gamma)). GRID measurements were made with melamine (C(sub 3)H(sub 6)N(sub 6)) as both target and slowing-down medium. The Doppler-broadened (gamma)-ray line shapes were analyzed by molecular dynamics simulations of the slowing-down process to obtain the lifetime values for four states in (sup 15)N. Preliminary results will be shown.