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Selective separation of ultra-fine particles by magnetophoresis

Description: The selective and-specific extraction of species of interest fiom local environmental and other sample sources are importaut fbr scientific research, industrial processes, and environmental applications. A novel process for selective separation of ultrafine particles using 'magnetophoresis' is investigated. The principle of this process is that the direction and velocity of particle movement in a magnetic field are determined by magnetic, gravitational, and drag fbrces. By controlling these fbrces, one is able to control the migration rates of different species and then magnetically fiactionate mixtures of species into discrete groups. This study demonstrated for the fist time the selective separation of various species, such as iron (111) oxide, cupric (11) oxide, samarium (In) oxide, and cerium (III) oxide, by magnetophoresis. To better understand this phenomenon, a fbrce-balance model was developed that provides a good interpretation of the experimental results.
Date: January 1, 2002
Creator: Ying, T. (Tung-yu); Prenger, F. Coyne; Wingo, R. M. (Robert M.) & Worl, L. A. (Laura A.)
Partner: UNT Libraries Government Documents Department

Experimental heat leak measurements on the APT 210 KW CW RF power coupler

Description: A cryogenic test rig was designed and fabricated to measure the heat leak from room temperature to 2 K from the Accelerator Production of Tritium (APT) 700 MHz, 210 kW continuous wave (CW) co-axial power coupler (PC). The outer conductor of the PC is stainless steel with 15 {micro}m copper film on the inside. The copper inner conductor operates at room temperature and contributes considerable infra-red radiation heat load to 2 K. Two thermal intercept heat exchangers cooled by supercritical helium are incorporated into the outer conductor to reduce the heat conducted to the lowest temperatures. A brief description of the experimental apparatus is presented. A comparison of the experimental measurements and the predictions of a detailed thermal model is given. There is also a discussion of anomalous behavior observed in the thermal intercepts, and fluctuations in the helium coolant properties.
Date: January 1, 2001
Creator: Blumenfelda, P. E.; Prenger, F. Coyne; Kelley, J. P. (John Patrick); Currie, S. A. (Scott A.); Stewart, J. A. (James A.) & Waynert, J. A. (Joseph A.)
Partner: UNT Libraries Government Documents Department

Gas generation over plutonium oxides in the 94-1 shelf-life surveillance program.

Description: The Department of Energy (DOE) is embarking upon a program to store large quantities of plutonium-bearing materials for up to fifty years. The Los Alamos National Laboratory Shelf Life Project was established to bound the behavior of plutonium-bearing material meeting the DOE 3013 Standard. The shelf life study monitors temperature, pressure and gas composition over oxide materials in a limited number of large-scale 3013 inner containers and in many small-scale containers. For the large-scale study, baseline plutonium oxides, oxides exposed to high-humidity atmospheres, and oxides containing chloride salt impurities are planned. The first large-scale container represents a baseline and contains dry plutonium oxide prepared according to the 3013 Standard. This container has been observed for pressure, temperature and gas compositional changes for less than a year. Results indicate that no detectable changes in pressure and gas composition are observed.
Date: January 1, 2002
Creator: Berg, J. M. (John M.); Harradine, D. M. (David M.); Hill, D. D. (Dallas D.); McFarlan, James T.; Padilla, D. D. (Dennis D.); Prenger, F. Coyne et al.
Partner: UNT Libraries Government Documents Department

Gas generation by pure and impure plutonium oxide materials in sealed containers.

Description: The Department of Energy (DOE) standard, DOE-STD-3013-2000, establishes criteria for stabilizing, packaging, and long term safe storage of plutonium-bearing materials at DOE facilities . The Standard applies to oxide or metal that contains at least 30 weight percent plutonium plus uranium. For oxide material a maximum of 5 kg of material is packaged in a nested set of two individually welded containers and the requirements include material stabilization at 950 C, 0 .5 weight percent moisture content or less, and less than nineteen watts of power per sealed container . The welded containers ensure that any gas generated due to radiolysis will be retained within the container . Although the 3013 package provides for a robust storage system, its long-term safety performance has not been demonstrated . To ensure failures do not occur while the sealed containers are being stored for up to 50 years, a DOE complex-wide integrated surveillance program has been established to measure the gas generation rates of these materials. At Los Alamos National Laboratory (LANL), the shelf life project monitors gases over oxide materials in a limited number of large-scale 3013 inner containers charged with 5 kg of material and in many small-scale containers with 10 gram samples taken from site-wide representative materials actually being stored . The small-scale containers allow more sample types and conditions to be studied. This information provides invaluable, defensible results for assuring safe long-term storage of these materials in sealed containers . Initial results on gas generation are presented.
Date: January 1, 2003
Creator: Berg, J. M. (John M.); McFarlan, James T.; Padilla, D. D. (Dennis D.); Veirs, D. K. (Douglas Kirk); Worl, L. A. (Laura A.); Harradine, D. M. (David M.) et al.
Partner: UNT Libraries Government Documents Department