arXiv subjects

A. Bers

Publications and source records attributed to A. Bers.

2 recordsLinked to original sources

arXiv2005

Vlasov Simulations of Trapping and Inhomogeneity in Raman Scattering

We study stimulated Raman scattering (SRS) in laser-fusion conditions with the Eulerian Vlasov code ELVIS. Back SRS from homogeneous plasmas occurs in sub-picosecond bursts and far exceeds linear theory. Forward SRS and re-scatter of back SRS are also observed. The plasma wave frequency downshifts from the linear dispersion curve, and the electron distribution shows flattening. This is consistent with trapping and reduces the Landau damping. There is some acoustic ($ω\propto k$) activity and possibly electron acoustic scatter. Kinetic ions do not affect SRS for early times but suppress it later on. SRS from inhomogeneous plasmas exhibits a kinetic enhancement for long density scale lengths. More scattering results when the pump propagates to higher as opposed to lower density.

physics.plasm-ph↗

arXiv2003

Coherent Acceleration of Magnetized Ions by Electrostatic Waves with Arbitrary Wavenumbers

This paper studies the coherent acceleration of ions interacting with two electrostatic waves in a uniform magnetic field B0. This is a generalization of an earlier analysis of waves propagating perpendicularly to B0 to include the effect of wavenumbers along B0. The Lie transformation technique is used to develop a perturbation theory describing the ion motion, and results are compared with numerical solutions of the complete equations of motion. Coherent energization occurs when the Doppler-shifted wave frequencies differ by nearly an integer multiple of the ion cyclotron frequency. When the difference in the parallel wavenumbers of the two waves is increased the coherent energization of ions is limited to a small part of the phase space. The energization of ions and its dependence on wave parameters is discussed.

physics.plasm-ph↗