Results 251 to 260 of about 1,568,609 (304)

Calibrating ion density profile measurements in ion thruster beam plasma

Review of Scientific Instruments, 2016
The ion thruster beam plasma is characterized by high directed ion velocity (104 m/s) and low plasma density (1015 m−3). Interpretation of measurements of such a plasma based on classical Langmuir probe theory can yield a large experimental error. This paper presents an indirect method to calibrate ion density determination in an ion thruster beam ...
Zun Zhang, Haibin Tang, Junxue Ren, Zhe Zhang, Joseph Wang   +4 more
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Ultrahigh Current Density Ion Implantation

JOM, 1987
A study of several engineering alloys implanted at ultrahigh current densities has revealed that the process induces no change in the bulk microsctructure of the materials. Even though temperatures induced during processing exceed the transformation (tempering and annealing) temperatures, there is insufficient time for nucleation and growth reactions ...
W. S. Sampath, R. Wei, P. J. Wilbur
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Ion-ion recombination at high ion density

Journal of Physics B: Atomic and Molecular Physics, 1985
By appeal to a Thomson-style treatment of recombination, it is shown that the rate for recombination of ions generated with uniform frequency within a reaction volume is a factor of 9/4 times greater than the rate for recombination of ions which approach each other from infinite separation.
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Repulsive ion—atom and ion—ion potentials from charge density overlap integrals

Chemical Physics, 1990
Abstract The short-range repulsive potentials for different combinations of the alkali ions Na+, K+, Rb+ and Cs+ and inert gas atoms, and between the same alkali ions are estimated using a recently suggested combining rule procedure. The comparison with ab initio first-order SCF calculations indicates an error of less than 20% for the combining rule ...
Carl Nyeland, K.T. Tang, J.Peter Toennies   +2 more
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Ion density in ionizing beams

Physics Letters A, 1969
Abstract A general method is given to calculate the density of ions created in ionizing beams. Application to elipsoidal boundaries (including very long and very broad beams), is simple and yields interesting results.
D.K. Callebaut, G.K. Knuyt
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Negative ion densities in NF3 discharges

Applied Physics Letters, 1984
This letter shows that the negative ion density in the NF3 discharge is one to two orders of magnitude larger than the electron density. A XeCl laser was used to photodetach the ions and the resultant excess electron population was measured using microwave interferometry.
K. E. Greenberg, G. A. Hebner, J. T. Verdeyen   +2 more
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Ion density in ionizing beams. I

Plasma Physics, 1978
The general equations are derived from which one may determine the steady, nonquasineutral ion density in a steady ionizing beam as a function of three basic but arbitrary data: the boundary conditions, the density of the ionizing beam and its ion production per unit of volume and time. The conditions of validity are discussed briefly. Part of the work
Dirk K Callebaut, Gilbert K Knuyt
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ELECTRON DENSITY IN ION-LASER DISCHARGES

Applied Physics Letters, 1971
A new analysis of the TE011 microwave-cavity mode applicable in the high-electron density range commonly found in ion-laser discharges is described. Measurements of the electron density in a cw argon-ion laser discharge in the pressure range where lasing action occurs are presented.
L. D. Pleasance, E. V. George
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High current density ion-beam extraction

Radiation Effects and Defects in Solids, 2005
High current density (up to 700 mA/cm2) ion-beam extraction has been studied by 3D code KOBRA3-INP [INP, Junkerstr. 99, 65205 Wiesbaden, Germany]. Ion beams with such high current densities can be generated by ECR ion source driven by 37.5 GHz/100 kW gyrotron [Golubev S.V. et al. Trans. Furion Sci. Technol., 47, n. 1T, fuste 8, 345].
S. Kondrashev, A. Balabaev, V. Zorin, A. Sidorov   +3 more
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Density functional studies of carbonium ions

Journal of the Chemical Society, Faraday Transactions, 1996
The structure and bonding of all isomeric forms of the carbonium ions CH5+, C2H7+, C3H9+, n-C4H11+, i-C4H11+ and neo-C5H13+ have been studied in depth by various quantum chemical techniques including semi-empirical, ab initio Hartree–Fock (HF), second-order Moller–Plesset (MP2) theory and those based upon density functional theory (DFT). Of the methods
Simon J. Collins, Patrick J. O'Malley
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