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 Pythagorean–hodograph (PH) quintic curve r(t), t∈[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 control–polygon legs of a quintic PH curve as these free complex parameters, the remaining three control–polygon legs can be expressed in terms of them and the roots of a quadratic or quartic equation. Consequently, depending on the chosen two control–polygon 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 control–polygon 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 one‐component‐plasma limit revisited

Transition inverse temperatures (or Γ values) at the fluid–solid phase boundary of Yukawa systems near the one‐component‐plasma (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 lattice‐dynamics calculations. The new molecular dynamics simulations also confirm that the bcc–fcc phase transition curve is in good agreement with that of the quasiharmonic theory in the regime κ≤1.4, where κ is the ratio of the Wigner–Seitz 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