948 resultados para intermediate energy heavy ion collision


Relevância:

30.00% 30.00%

Publicador:

Resumo:

"Date Declassified: September 23, 1955."

Relevância:

30.00% 30.00%

Publicador:

Resumo:

"Date Declassified: September 23, 1955."

Relevância:

30.00% 30.00%

Publicador:

Resumo:

"Contract AT(49-1)-535."

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The investigation of the electrolytic precipitation of uranium from a sample of acid leach liquor in an ion exchange membrane cell has been conducted on leach liquor from the Vitro Co. This leach liquor can be treated by the above means to precipitate essentially all the uranium and simultaneously to produce additional acid which may be used for further leaching.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Electrolytic precipitation of uranium from ion-exchange resin eluates has been investigated in a three-compartment cell. A relatively low-energy consumption is required and anodic attack is reduced to a negligible quantity. During the precipitation, acid is produced in sufficient quantity for use as eluant for subsequent eluting operations. The recovered uranium is in the form of a rapid settling, fast filtering precipitate which is easily washed with water to reduce the chloride content to a tolerable concentration.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

"Date Declassified: September 23, 1955."

Relevância:

30.00% 30.00%

Publicador:

Resumo:

"Date Declassified: September 23, 1955."

Relevância:

30.00% 30.00%

Publicador:

Resumo:

"Date Declassified: September 23, 1955."

Relevância:

30.00% 30.00%

Publicador:

Resumo:

"United States Atomic Energy Commission, Savannah River Operations Office, Contract AT (38-1) 213, supplements 1 & 2."

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Issues are simultaneously published in both the "TID" and "SL" Series, but numbering is different.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

We study the evolution of structural defects in AlxGa1-xN films (with x=0.0-0.6) bombarded with kilo-electron-volt heavy ions at 77 and 300 K. We use a combination of Rutherford backscattering/channeling spectrometry and cross-sectional transmission electron microscopy. Results show that an increase in Al content not only strongly enhances dynamic annealing processes but can also change the main features of the amorphization behavior. In particular, the damage buildup behavior at 300 K is essentially similar for all the AlGaN films studied. Ion-beam-produced disorder at 300 K accumulates preferentially in the crystal bulk region up to a certain saturation level (similar to50%-60% relative disorder). Bombardment at 300 K above a critical fluence results in a rapid increase in damage from the saturation level up to complete disordering, with a buried amorphous layer nucleating in the crystal bulk. However, at 77 K, the saturation effect of lattice disorder in the bulk occurs only for xgreater than or similar to0.1. Based on the analysis of these results for AlGaN and previously reported data for InGaN, we discuss physical mechanisms of the susceptibility of group-III nitrides to ion-beam-induced disordering and to the crystalline-to-amorphous phase transition. (C) 2004 American Institute of Physics.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Wurtzite GaN epilayers bombarded at 300 K with 200 MeV Au-197(16+) ions are studied by a combination of transmission electron microscopy (TEM) and Rutherford backscattering/channeling spectrometry (RBS/C). Results reveal the formation of near-continuous tracks propagating throughout the entire similar to1.5-mum-thick GaN film. These tracks, similar to100 Angstrom in diameter, exhibit a large degree of structural disordering but do not appear to be amorphous. Throughout the bombarded epilayer, high-resolution TEM reveals planar defects which are parallel to the basal plane of the GaN film. The gross level of lattice disorder, as measured by RBS/C, gradually increases with increasing ion fluence up to similar to10(13) cm(-2). For larger fluences, delamination of the nitride film from the sapphire substrate occurs. Based on these results, physical mechanisms of the formation of lattice disorder in GaN in such a high electronic stopping power regime are discussed. (C) 2004 American Institute of Physics.