Equipoise-3: a two dimensional, two-group, neutron diffusion code for the ibm-7090 computer

TL;DR: EQUIPOISE-3 as mentioned in this paper is an IBM-7090 FORTRAN programmed code for the solution of two-group, two-dimensional, neutron diffusion equations, and it can solve problems in either rectangular or cylindrical geometry.

Abstract: EQUIPOISE-3 is an IBM-7090 FORTRAN programmed code for the solution of two-group, two-dimensional, neutron diffusion equations. A maximum of 2l00 mesh points may be used, and the code will solve problems in either rectangular or cylindrical geometry. Logarithmic derivative boundary conditions are allowed, and removal of neutrons from both groups is permitted. Adjoint fluxes with the associated fluxadjoint flux regional integrals may be calculated automatically if desired. A constant buckling, group-dependent buckling, or region-dependent buckling may be specified for rectangular geometry. This program is intended to fill the need for a rapid two-dimensional calculation suitable for survey calculations. During the iterative part of the computations, all operations are carried out in the core memory. The magnetic tape memory is used only for input, output, and program storage. The running time for a 1000-point problem requiring 100 iterations would be about 3 min.(auth)