Title: High-precision isotopic analysis of nanogram quantities of plutonium
Abstract: A surface ionization-diffusion-type ionization source that uses a rhenium filament overplated with platinum has been developed and optimized for 0.5- to 2-ng plutonium samples. This source is capable of measuring the /sup 240/Pu//sup 239/Pu atom ratio in nuclear-test-debris samples to 0.15% precision and accuracy at the 95% confidence level.