Parts Per Billion Doping and Characterization of Uranium Distribution in an Epoxy Polymer Matrix

摘要

Formulating an epoxy polymer provides a broadly applicable method for homogeneously doping a chemically stable, particulate-resistant, and radiation-hardened matrix with virtually any trace elements of interest. In the example reported, control of uranium levels over the range, 15 (mu)g/g-15 ng/g, is demonstrated. Fission track density determinations, referenced to NIST SRMs, indicate +-5percent variations in lateral uranium distributions. Determinations of levels of uranium impurities in commercially available high-purity samples of graphite, fused silica, and aluminum show respective nanogram per gram ranges of 3 +- 0.1-5 +- 0.3, 3 +- 0.8-27 +- 2, and 113 +- 11-546 +- 11. The prepared polymer materials cover 3 orders of magnitude of uranium levels in an ideal matrix. This accomplishes the prerequisite for subsequent investigations of the chemistry occurring at fission fragment-induced damage sites of selected track registering materials as a function of controlled reactive site densities. The matrix also serves as a source of swift heavy ions for creating nanoscale features in dielectric materials.