The Use Of Polytetrafluoroethylene (Teflon (R)) Containing Filter/Moderators For Epithermal Neutron Beam Production

We have investigated the suitability of fluorinated hydrocarbon polytetrafluoroethylene (PTFE) for application in the filter/moderator of an epithermal beam. We show that the neutronics performance, cost, and fabricability of Al and PTFE compares favorably with other good filter/moderator materials such as Al/Al2O3, Al/C, and Fluental (R). In this study, we have carried out irradiation tests to evaluate the performance of PTFE in the mixed gamma and fast neutron environment expected for the MIT Fission Converter epithermal neutron beam application. The irradiation stability was found to be more than adequate for the planned application.