3 research outputs found
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A fieldable instrument for waterborne radionuclide detection
In monitoring effluent leaving its sites, US DOE assays for alpha- emitting radionuclides (U, transuranics) to ensure compliance with regulatory limits. Because alpha emissions can only by detected over a short range in water ({approximately}40{mu}m), the conventional approach is to collect samples for processing in a central laboratory; a time-consuming and cost procedure ensues to separate and measure the radionuclides. Because of the sporadic nature of sampling processes, there is the possibility that a release may go undetected. We are addressing this issue by a developing a real-time, field- deployable instrument which incorporates a proprietary film that selectively binds radionuclides from dilute aqueous samples. By combining the film with an appropriate alpha spectrometer, we have developed a fieldable system that can operate as an autonomous monitor in a batch or continuous manner. Laboratory results to date have been encouraging. Positive identification of U and Pu has been made by resolving the energy spectrum of emitted alphas. Sensitivity for U is at the 10 part per trillion level (15 femtocuries per liter)
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Recent trends in inorganic mass spectrometry
The field of inorganic mass spectrometry has seen substantial change in the author`s professional lifetime (over 30 years). Techniques in their infancy 30 years ago have matured; some have almost disappeared. New and previously unthought of techniques have come into being; some of these, such as ICP-MS, are reasonably mature now, while others have some distance to go before they can be so considered. Most of these new areas provide fertile fields for researchers, both in the development of new analytical techniques and by allowing fundamental studies to be undertaken that were previously difficult, impossible, or completely unforeseen. As full coverage of the field is manifestly impossible within the framework of this paper, only those areas with which the author has personal contact will be discussed. Most of the work originated in his own laboratory, but that of other laboratories is covered where it seemed appropriate
Internal glow discharge-fourier transform ion cyclotron resonance mass spectrometry
A glow discharge (GD) ion source has been developed to work within the high magnetic field of a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. Characteri- zation of this source revealed that the optimum operating voltage, pressure, and current are significantly lower than those for normal glow discharges. The sputter rate was lowered to 1/30th of that found with a normal glow discharge source operated external to the high magnetic field region. Operation of the GD source closer to the FTICR analyzer cell than with previous experimental designs resulted in improved ion transport efficiency. Preliminary results from this internal GD source have established detection limits in the low parts per million range for selected elemental species. (J Am Soc Mass Spectrom 1996, 7, 923–929