Boron Autoradiography with the Electron Microscope

Abstract

HERE we report an improvement to an autoradiographic technique¹ for determining the spatial distribution in a solid of boron present at parts per million concentrations. The conventional technique is based on recording damage tracks produced by the products of the ¹⁰B(n,α)⁷Li reaction in cellulose acetobutyrate (CAB) and made visible in the optical microscope by etching in hot alkali solution. The technique using optical microscopy has a resolution of 1–2 microns and is sufficiently sensitive to show the distribution of about 0.5 p.p.m. of natural boron.