Vladimir M. Malkin

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Backward Raman amplification (BRA) in plasmas holds the potential for longitudinal compression and focusing of powerful x-ray pulses. In principle, this method is capable of producing pulse intensities close to the vacuum breakdown threshold by manipulating the output of planned x-ray sources. The minimum wavelength limit of BRA applicability to compression(More)
The very promising scheme for producing ultrapowerful laser pulses through Raman backscattering of pump lasers in plasmas can be jeopardized by superluminous precursors. Growing from the leading part of the Raman pumped seed pulse, these precursors can disturb the plasma and the pump ahead of the pumped pulse. These ruinous effects, however, might be(More)
Experiments are described in which a 1 mJ, 1 ps, 1200 nm seed laser beam is amplified by the interaction with an intersecting 350 J, 1 ns, 1054 nm pump beam in a low density 1 1019 /cm3 plasma. The transmission of the seed beam is observed to be enhanced by 25 when the plasma is near the resonant density for stimulated Raman scattering, compared to measured(More)
New powerful soft x-ray sources may be able to access intensities needed for backward Raman amplification (BRA) of x-ray pulses in plasmas. However, high plasma densities, needed to provide enough coupling between the pump and seed x-ray pulses, cause strong damping of the Langmuir wave that mediates energy transfer from the pump to the seed pulse. Such(More)
on Raman amplification efficiency in plasma N. A. Yampolsky, N. J. Fisch, V. M. Malkin, E. J. Valeo, R. Lindberg, J. Wurtele, J. Ren, S. Li, A. Morozov, and S. Suckewer Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544, USA Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543, USA Department of(More)
Backward Raman compression in plasma enables pulse compression to intensities not available using material gratings. Mediating the compression with higher density plasma generally produces shorter and therefore more intense output pulses. However, very high density plasma, even if sufficiently tenuous to be transparent to the laser, also produces group(More)
The energy deposition of a relativistic electron beam in a plasma can be managed through turning on or off fast beam-plasma instabilities in desirable regions. This management may enable new ways of realizing the fast-igniter scenario of inertial fusion. Collisional effects alone can decelerate electrons of at most a few MeV within the core of an(More)
In the process of backward Raman amplification (BRA), the leading layers of the seed laser pulse can shadow the rear layers, thus weakening the effective seeding power and affecting parameters of output pulses in BRA. We study this effect numerically and also analytically by approximating the pumped pulse by the "pi-pulse" manifold (family) of self-similar(More)
Extremely large laser power might be obtained by compressing laser pulses through backward Raman amplification (BRA) in plasmas. Premature Raman backscattering of a laser pump by plasma noise might be suppressed by an appropriate detuning of the Raman resonance, even as the desired amplification of the seed persists with a high efficiency. In this paper we(More)
The theory of transient forward stimulated Raman scattering (FSRS) of rapidly amplified short laser pulses is put forth to complement the classical theory for FSRS of stationary pulses. Quantitative conditions for FSRS suppression are identified. In particular, it is shown quantitatively how the limitation imposed by pumped pulse FSRS on the output laser(More)