Characterization of the IPNS radiation effects module.

Paul Scherrer Institute, Villigen, Switzerland The radiation effects module (REM) at Argonne’s Intense Pulsed Neutron Source has been used for a wide variety of irradiation experiments over the facility’s lifetime. Recently planned and executed experiments include studies of radiation damage in optical fibers and scintillators for use in high-energy physics detectors, irradiation of optical components for SNS neutron scattering instruments, irradiation of dilute fissile mixtures to study separations processes, and irradiation of foils and wires for neutronic characterization of the facility. Characterization of the neutron flux profile in the REM is essential for planning experiments and analyzing the resulting data. In this paper we compare the neutron fluxes obtained from recent MCNPX calculations with the results of previous experiments which used a set of activation foils to measure the neutron flux from high energies down to thermal at two locations in the REM. We also compare recent activation measurements in nickel and bismuth samples with predictions using the CINDER90 code and neutron fluxes generated using MCNPX.