Efficiency of Neutron Converter Screens for Microfilter Production

Abstract

Production of microfilter polymer membrane was studied by using alpha particles from ¹⁰B(n, α)⁷ Li and⁶Li(n,α)³H nuclear reactions and fission fragment from U-235 nuclear fission. The high-energy charged particlecaused latent track on polymer film which was enlarged by chemical etching in 70 ^oC 6.25 N NaOH solution for 80 minutes. The examination of 4 types of polymer films i.e., CR-39, cellulose acetate, polyethylene terephthalateand thin film polycarbonate showed that only CR-39 film could observe alpha tracks. The track range was shorterthan film thickness. Fission track could be found in all of the 4 types of films in which only 6 micrometerpolycarbonate film was porous. The pore density of fission track from uranium screen on polycarbonate film was220 ± 70 pore mm^-2 with 4.43 ± 0.87 micrometer pore size. The converter efficiency of neutron to fission trackwas 1.5 x 10^-8 - 2.9 x 10^-8 tracks per neutron.

Keywords : Neutron / Neutron Converter Screen / Micropore Filter / Nuclear Reaction (n, α)/Polymer / Chemical Etching / Nuclear Fission Reaction