Analytical mass spectrometry section:

Quantification of neptunium by isotope dilution mass spectrometry

“…The mass spectrometer used in this study is a modified version of the 30.5-cm-radius, 90°-deflection, thermal ionization instrument that was developed at the National Bureau of Standards (NBS). 5 The spectrometer is designed to operate as an ultrahighvacuum instrument. Its pumping system consists of a mercury diffusion pump and a 140-^/s ion pump.…”

Geological Survey research 1972

“…The water in Fremont Lake was higher in mineral content than the inflow from Fremont River when sampled in July 1970. In comparing the composition of the inflow with that of the surface water at site 1 (table 10), the increase among conservative cations and anions varies from 0 percent for potassium to 64 percent for calcium.…”

“…Our method, modified from that of Cameron and others, was established independently of other laboratories. Our reagent preparation was somewhat different from that of others (Cameron and others, 1969;Shields, 1970), and the method was thoroughly tested for fractionation of lead isotopes. BCR-1 was analyzed for lead isotopic composition by the silica gel-phosphate method and the result, which was corrected by the fractionation factor, was compared with the double-spike corrected value.…”

The Absolute Isotopic Abundance and Atomic Weight of a Reference Sample of Silver

“…The isotopic ralio measurements were made using two nearly identical 90 0 , 30 em radius of curvature solid sample mass spectrometers equipped with a "z" lens focusing source [18].…”

“…The collector was a deep bucket Faraday cup equipped with a 50 percent transmission grid shadowing a series of suppression grids [18][19][20]. The measuring circuit consisted of two vibrating reed electrometers (VRE) and a voltage-to-frequency conversion system which transmits data to a computer for data acquisition.…”