167 research outputs found
Thermodynamics of strongly-coupled Yukawa systems near the one-component-plasma limit. II. Molecular dynamics simulations
R. T. Farouki and S. Hamaguchi, J. Chem. Phys. 101, 9885 (1994) https://doi.org/10.1063/1.46795
Polarization force on a charged particulate in a nonuniform plasma
S. Hamaguchi and R. T. Farouki, Phys. Rev. E 49, 4430, 199
Phase transitions of dense systems of charged "dust" grains in plasmas
R. T. Farouki and S. Hamaguchi, Appl. Phys. Lett. 61, 2973 (1992) https://doi.org/10.1063/1.10803
Ion energetics in collisionless sheaths of rf process plasmas
S. Hamaguchi, Physics of Fluids B: Plasma Physics 4, 2362 (1992) https://doi.org/10.1063/1.86020
Construction of planar quintic Pythagorean-hodograph curves by control-polygon constraints
In the construction and analysis of a planar Pythagoreanâhodograph (PH) quintic curve r(t), tâ[0,1] using the complex representation, it is convenient to invoke a translation/rotation/scaling transformation so r(t) is in canonical form with r(0)=0, r(1)=1 and possesses just two complex degrees of freedom. By choosing two of the five controlâpolygon legs of a quintic PH curve as these free complex parameters, the remaining three controlâpolygon legs can be expressed in terms of them and the roots of a quadratic or quartic equation. Consequently, depending on the chosen two controlâpolygon legs, there exist either two or four distinct quintic PH curves that are consistent with them. A comprehensive analysis of all possible pairs of chosen control polygon legs is developed, and examples are provided to illustrate this controlâpolygon paradigm for the construction of planar quintic PH curves
Ponderomotive force and ion energy distributions in an rf sheath
The incident-ion energy distribution in a collisionless radio-frequency (rf) sheath is derived analytically for a general electric-field configuration in the high-frequency regime. The analysis is based on a two-time-scale asymptotic expansion of the ion equation of motion, where the ratio of the ion transit frequency tr to the rf frequency is assumed to be small. It is shown that the ponderomotive force due to the rf modulation of the electric field exerts a retarding effect on the ion motion, counteracting the dc-bias field. The results obtained here are applicable to rf-discharge-based process tools used in microelectronics fabrication, where the conditions of low collisionality and high rf frequency are usually satisfied. © 1992 The American Physical Society.S. Hamaguchi, R. T. Farouki, and M. Dalvie, Phys. Rev. Lett. 68, 44, 199
Phase diagram of Yukawa systems near the oneâcomponentâplasma limit revisited
Transition inverse temperatures (or Î values) at the fluidâsolid phase boundary of Yukawa systems near the oneâcomponentâplasma (OCP) limit have been evaluated by molecular dynamics simulations. These values are systematically smaller than those obtained in an earlier study by Farouki and Hamaguchi [J. Chem. Phys. 101, 9885 (1994)]. The discrepancy is attributed to the fact that, in the earlier study, the harmonic entropy constants were approximated by that of the OCP, whereas the new results are based on more accurate harmonic entropy constants obtained from latticeâdynamics calculations. The new molecular dynamics simulations also confirm that the bccâfcc phase transition curve is in good agreement with that of the quasiharmonic theory in the regime Îșâ€1.4, where Îș is the ratio of the WignerâSeitz radius to the Debye length. Examples of Yukawa systems include dusty plasmas and colloidal suspensions. © 1996 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69874/2/JCPSA6-105-17-7641-1.pd
Intrabeam scattering analysis of measurements at KEK's ATF damping ring
We derive a simple relation for estimating the relative emittance growth in x
and y due to intrabeam scattering (IBS) in electron storage rings. We show that
IBS calculations for the ATF damping ring, when using the formalism of
Bjorken-Mtingwa, a modified formalism of Piwinski (where eta squared divided by
beta has been replaced by the dispersion invariant), or a simple high-energy
approximate formula all give results that agree well. Comparing theory,
including the effect of potential well bunch lengthening, with a complete set
of ATF steady-state beam size vs. current measurements we find reasonably good
agreement for energy spread and horizontal emittance. The measured vertical
emittance, however, is larger than theory in both offset (zero current
emittance) and slope (emittance change with current). The slope error indicates
measurement error and/or additional current-dependent physics at the ATF; the
offset error, that the assumed Coulomb log is correct to within a factor of
1.75.Comment: 17 pages, 6 figures, .bbl fil
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