An Automated Transportable Mass Spectrometer

A commercial Gas Chromatograph Mass Spectrometer has been modified for use as a rapid, transportable tool for the isotopic analysis of uranium and plutonium. The single rhenium filament thermal emission source is vacuum lock mounted for rapid sample interchange. Filament current is computer controlled. Ions are collected by a Galileo infinite dynode multiplier which is fed to a log preamplifier and then digitized. Using resin bead technology, a 10 nanogram sample is analyzed to 1% accuracy in 6 minutes. After sample loading all operations are totally computer controlled, and results including sample data, are printed out on tape. During a run, more than 10 data points are observed and averaged. The instrument weighs 98 kgms and can be relatively easily carried short distances by 2 persons.