Effects of laser beam smoothing on stimulated Raman scattering in exploding foil plasmas

被引:53
作者
Montgomery, DS [1 ]
Moody, JD [1 ]
Baldis, HA [1 ]
Afeyan, BB [1 ]
Berger, RL [1 ]
Estabrook, KG [1 ]
Lasinski, BF [1 ]
Williams, EA [1 ]
Labaune, C [1 ]
机构
[1] ECOLE POLYTECH, F-91128 PALAISEAU, FRANCE
关键词
D O I
10.1063/1.871682
中图分类号
O35 [流体力学]; O53 [等离子体物理学];
学科分类号
070204 ; 080103 ; 080704 ;
摘要
Time-resolved spectra of backward stimulated Raman scattering (SRS) were measured from the interaction of a 527 nm laser with a preformed plasma. The effect of laser smoothing by spectral dispersion (SSD) was studied using laser bandwidth (Delta lambda/lambda=0.1%) and varying the laser intensity (2-20x10(14) W/cm(2)). A broad SRS spectrum extending to short wavelengths was observed for the high-intensity, Delta lambda/lambda=0 case. Narrow spectra corresponding to the peak plasma density were observed for cases with either high intensity and Delta lambda/lambda similar to 0.1%, or with low intensity and Delta lambda/lambda=0. Simulations of the filamentation process were performed for the conditions of these experiments. The simulations show that laser smoothing stabilizes filamentation for high-intensity interactions, and that filaments are stable without smoothing for low intensity. The predicted onset of filamentation without smoothing correlates with the growth of short wavelength SRS. These experimental results are presented and models are discussed that may help explain the data. (C) 1996 American Institute of Physics.
引用
收藏
页码:1728 / 1736
页数:9
相关论文
共 26 条
[1]  
AFEYAN BB, 1993, THESIS U ROCHESTER R
[2]   EVIDENCE OF STIMULATED RAMAN-SCATTERING OCCURRING IN LASER FILAMENTS IN LONG-SCALE-LENGTH PLASMAS [J].
AFSHARRAD, T ;
COE, SE ;
WILLI, O ;
DESSELBERGER, M .
PHYSICS OF FLUIDS B-PLASMA PHYSICS, 1992, 4 (05) :1301-1322
[3]  
BACK CA, 1995, COMMUNICATION
[4]   STIMULATED BRILLOUIN-SCATTERING IN INHOMOGENEOUS FLOWING PLASMA [J].
BERGER, RL .
PHYSICS OF FLUIDS, 1984, 27 (07) :1796-1803
[5]   INFLUENCE OF SPATIAL AND TEMPORAL LASER-BEAM SMOOTHING ON STIMULATED BRILLOUIN-SCATTERING IN FILAMENTARY LASER-LIGHT [J].
BERGER, RL ;
LASINSKI, BF ;
LANGDON, AB ;
KAISER, TB ;
AFEYAN, BB ;
COHEN, BI ;
STILL, CH ;
WILLIAMS, EA .
PHYSICAL REVIEW LETTERS, 1995, 75 (06) :1078-1081
[6]   EFFECT OF PLASMA NOISE SPECTRUM ON STIMULATED SCATTERING IN INHOMOGENEOUS-PLASMA [J].
BERGER, RL ;
WILLIAMS, EA ;
SIMON, A .
PHYSICS OF FLUIDS B-PLASMA PHYSICS, 1989, 1 (02) :414-421
[7]   THEORY AND 3-DIMENSIONAL SIMULATION OF LIGHT FILAMENTATION IN LASER-PRODUCED PLASMA [J].
BERGER, RL ;
LASINSKI, BF ;
KAISER, TB ;
WILLIAMS, EA ;
LANGDON, AB ;
COHEN, BI .
PHYSICS OF FLUIDS B-PLASMA PHYSICS, 1993, 5 (07) :2243-2258
[8]   RANDOM-PHASE PLATES FOR BEAM SMOOTHING ON THE NOVA LASER [J].
DIXIT, SN ;
THOMAS, IM ;
WOODS, BW ;
MORGAN, AJ ;
HENESIAN, MA ;
WEGNER, PJ ;
POWELL, HT .
APPLIED OPTICS, 1993, 32 (14) :2543-2554
[9]   EVIDENCE THAT STIMULATED RAMAN-SCATTERING IN LASER-PRODUCED PLASMAS IS AN ABSOLUTE INSTABILITY [J].
DRAKE, RP ;
WILLIAMS, EA ;
YOUNG, PE ;
ESTABROOK, K ;
KRUER, WL ;
BALDIS, HA ;
JOHNSTON, TW .
PHYSICAL REVIEW LETTERS, 1988, 60 (11) :1018-1021
[10]   KINETIC-THEORY OF LASER FILAMENTATION IN PLASMAS [J].
EPPERLEIN, EM .
PHYSICAL REVIEW LETTERS, 1990, 65 (17) :2145-2148