T1 and U1 approximations to neutron transport equation in one-dimensional spherical geometry

Abstract

The diffusion lengths for one-speed neutrons are calculated by solving transport equation in one-dimensional spherical geometry. The pseudo-slab transport equation is obtained using a reasonable approach. The neutron angular flux is expanded in a series of both the Chebyshev polynomials of first and second kinds. Then analytic and numerical results for asymptotic relaxation length are obtained by applying first order approximations to the transport equation and they are compared with each other.