부산대학교 도서관

A method is developed for obtaining multigroup cross sections from the BN approximation in a way similar to that of the P/sub N/ theory. It is shown that from a programming point of view both formalisms are very close. Moreover, it is sometimes advantageous to considerably reduce the resulting matrix for the B/sub N/ approximation to the size of the matrix for the B/sub 0/ approximation by eliminating the higher angular moments. Although the new method requires less memory and computing time, the resulting system of equations is mathematically equivalent. (auth)