Vacuum isotope separation

British Columbia, and three at the U.S. Army Ordinance Works operated by the DuPont Company at Morgantown, West Virginia Cluldersburg, Alabama and Dana, Indiana. The plant at Trail used chemical exchange between hydrogen gas and steam for the initial isotope separation followed by electrolysis for final concentration. The three plants in the United States used vacuum distillation of water for the initial separation followed by electrolysis. Details of these plants and their operations may be found in the Hterature (10). 

The XPS valence band spectra for the dioxides of the transuranium elements (from Np to Bk) have been presented in an extensive and pioneering work that also includes core level spectra and has been for a long time the only photoemission study on highly radioactive compounds. High resolution XPS spectra (AE = 0.55 eV) were recorded on oxidized thin metal films (30 A) deposited on platinum substrates with an isotope separator. (The oxide films for Pu and the heavier actinides may contain some oxides with lower stoichiometry, since starting with Pu, the sesquioxides of the heavier actinides begin to form in high vacuum conditions.)... 

The spectrum of uranium metal vapor is complex with over 3x10 lines in the visible region. Still, many of these are very sharp and show sufficient isotope separation to permit selective excitation. The basic idea of AVLIS is to irradiate uranium metal vapor at a concentration around 10 atoms cm (higher concentrations destroy the separation due to collisional broadening). Uranium is a refractory metal, and vaporization is difficult. Electron bombardment under high vacuum yields an atomic beam that passes through the laser radiation field where U is selectively excited. 

Sources for forming ions of condensable species (film ions) in vacuum began with the development of ion sources for isotope separation using mass spectrometers such as the Calutron in the 19408 and continues in the present. 

The isotopically enriched carbonyl can be separated from the CO and SF6 in a circulating vacuum system.]... 

Mulliken, R.S. and Harkins, W.D. (1922). The separation of isotopes. Theory of resolution of isotopic mixtures by diffusion and similar processes. Experimental separation of mercury by evaporation in a vacuum. Journal of the American Chemical Society 44 37-65. 

The MC-ICP-MS consists of four main parts 1) a sample introduction system that inlets the sample into the instrument as either a liquid (most common), gas, or solid (e.g., laser ablation), 2) an inductively coupled Ar plasma in which the sample is evaporated, vaporized, atomized, and ionized, 3) an ion transfer mechanism (the mass spectrometer interface) that separates the atmospheric pressure of the plasma from the vacuum of the analyzer, and 4) a mass analyzer that deals with the ion kinetic energy spread and produces a mass spectrum with flat topped peaks suitable for isotope ratio measurements. 

Some of the materials for which chromatographic separation should be considered are essential oils, terpenoids, steroids, alkaloids, pharmaceuticals, metal chelates, isotopes, and dose-boiling isomers. For easy separations, vacuum distillation, liquid-liquid extraction, and fractional crystallization are less expensive. 

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