Inverse Bremsstrahlung Stabilization of Noise in the Generation of Ultra-short Intense Pulses by Backward Raman Amplification

Journal Article · Fri Oct 17 00:00:00 EDT 2003 · Physics of Plasmas

OSTI ID:15013662

Berger, R L; Clark, D S; Solodov, A; Valeo, E J; Fisch, N J

Inverse bremsstrahlung absorption of the pump laser beam in a backward Raman amplifier over the round-trip light transit time through the sub-critical density plasma can more than double the electron temperature of the plasma and produce time-varying axial temperature gradients. The resulting increased Landau damping of the plasma wave and detuning of the resonance can act to stabilize the pump against unwanted amplification of Langmuir noise without disrupting nonlinear amplification of the femtosecond seed pulse. Because the heating rate increases with the charge state Z, only low-Z plasmas (hydrogen, helium, or helium-hydrogen mixtures) will maintain a low enough temperature for efficient operation.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 15013662
• Report Number(s): UCRL-JRNL-200415; PHPAEN; TRN: US0801352
• Journal Information: Physics of Plasmas, Vol. 11, Issue 5; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION
AMPLIFICATION
BREMSSTRAHLUNG
CHARGE STATES
ELECTRON TEMPERATURE
HEATING RATE
LANDAU DAMPING
PLASMA
PLASMA WAVES
STABILIZATION
TEMPERATURE GRADIENTS