Implementation of a tree algorithm in MCNP code for nuclear well logging applications

The goal of this paper is to develop some modeling capabilities that are missing in the current MCNP code. Those missing capabilities can greatly help for some certain nuclear tools designs, such as a nuclear lithology/mineralogy spectroscopy tool. The new capabilities to be developed in this paper include the following: zone tally, neutron interaction tally, gamma rays index tally and enhanced pulse-height tally. The patched MCNP code also can be used to compute neutron slowing-down length and thermal neutron diffusion length.

► Tree structure programming is suitable for Monte-Carlo based particle tracking.
► Enhanced pulse height tally is developed for oilwell logging tool simulation.
► Neutron interaction tally and gamma ray index tally for geochemical logging.