Activation Calculations of the Moderator for the Low Energy Neutron Source

Abstract

The Low Energy Neutron Source (LENS) at the Indiana University Cyclotron Facility (IUCF) will accelerate protons in the range of 7 to 22 MeV. The protons are incident on a beryllium target via the (p,n) reaction, where the majority of the neutrons continue in the forward direction. The neutrons are then moderated in solid methane, reaching energy levels of 4 meV or lower. It is the activation levels of the moderator and related containers and hardware materials that are of particular concern. The calculations that follow are designed to estimate the biological safety and activation of materials in the vicinity of the moderator.