Comparison of predicted signals from the delayed fission neutron and prompt fission neutron uranium logging methods

Abstract

A mathematical formalism is developed whereby the expected signal from a delayed fission neutron uranium logging experiment can be calculated efficiently. An assumption that the logging geometry can be approximated by one-dimensional spherical geometry is made in order to facilitate the calculation of neutron-transport results that are needed to evaluate the formalism. Sample results from these calculations are used to form a comparison of the magnitudes of prompt and delayed fission neutron logging signals. respectively. for various observation times and amounts of water in the logging borehole.

Calculation of the response of cylindrical targets to collimated beams of particles using one-dimensional adjoint transport techniques. [LMFBR]

“…The use of adjoint calculations to obtain neutron penetration factors in spherical geometry has been described by Hansen and Sandmeier. 1 Numerous applications of this technique .in spherical and slab geometry, using both discrete ordinates and Monte Carlo transport codes, bave been published (e.g., see References 2,3,and 4). The.…”