Calculation Of Double Differential Cross Section For N+d Breakup Reaction Based On Phase Space Method

The study of few-body nuclear reaction plays a significant role in investigating the structure of light nuclei, the mechanism of nuclear reaction and the nature of nuclear force. While n+d three-body break-up reaction is one of the unique few-body nuclear reactions and an important means of studying nucleon-nucleon interaction and three-nucleon forces.In addition, the double-differential neutron cross section of n+d three-body break-up reaction is from the reaction channels of elastic scattering and three-body breakup, the data of which is able to be extracted experimentally.Based on the phase-space theoretical method for few-body nuclear reaction with unifor-m momentum distribution, this paper does a certain amount of work on aspects of nonuni-form momentum distribution and anisotropy in center-of-mass frame. For the nonuniform momentum distribution, "three forms of momentum distribution function including decay-ing form, gaussian-like form and gaussian form are proposed and for each form, formulas calculating double-differential cross section of three-body breakup reaction are deduced. The calculations for double-differential neutron cross section from deuteron breakup by about 14 MeV neutron is performed through the above formulas and the theoretical results are compared with the experimental values from different literatures, which shows that the calculated results on basis of decaying form are not good as that of gaussian-like form and gaussian form and calculations on basis of the latter two momentum distributions a-gree to some degrees with the experimental data in small angles, but not agreed well near the maximum outgoing energy. Besides, for the larger angles, the calculated results are also not agreed well with the experimental data. Thus, we further take into account the anisotropy, and the angle relation in form of legendre polynomial expansion is added into the double-differential cross section in center of mass. After considering this angle relation, the theoretical calculation on basis of gaussian distribution is in well agreement with the experimental data of double-differential neutron cross section from deuteron breakup by about 14 MeV neutron, which means the consideration of the angle relation has certain rationality. In addition, The theoretical prediction is given by considering comprehensively the momentum distribution function and anisotropy. A verification is done by comparison with the new measured data with incident energy of 8.22 MeV, which shows our theory is reasonable. Thus the conclusion is that both momentum distribution and anisotropy should be considered in phase-space theoretical method in order to agree with the experi-mental values. However, the deviation between our calculation and the experimental data still exists near the maximum emitting energy, so further researches about these two as-pects are needed so as to obtain the most reasonable momentum distribution function and expression accurately embodying anisotropy without dependence of fitting parameters.