Model simulations of Langmuir wave turbulence induced by the Raman instability

Physics of Plasmas

Volumn 5, Issue 11, 1998, Pages 3876-3885

  Rose, Harvey A ^a  

^a LOS ALAMOS NATIONAL LABORATORY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ASYMPTOTIC STABILITY; BANDWIDTH; CARRIER CONCENTRATION; COMPUTER SIMULATION; DAMPING; ELECTRIC FIELDS; ELECTRONS; FOURIER TRANSFORMS; ION ACOUSTIC WAVES; NUMERICAL METHODS; PLASMA WAVES; RAMAN SCATTERING;

ION ACOUSTIC DAMPING RATE COEFFICIENT; LANGMUIR DECAY INSTABILITY; LANGMUIR WAVE TURBULENCE; RAMAN INSTABILITY; STIMULATED RAMAN BACKSCATTER; ZAKHAROV EQUATION;

PLASMA TURBULENCE;

EID: 0032210790     PISSN: 1070664X     EISSN: None     Source Type: Journal    
DOI: 10.1063/1.873107     Document Type: Article

References (28)

1. H. A. Rose, "The broad bandwidth paradigm for stimulated Raman scattering in laser-plasma interactions," submitted to Phys. Plasmas.
2. V. E. Zakharov, Zh. Eksp. Teor. Fiz. 62, 1745 (1972); [Sov. Phys. JETP 35, 908 (1972)].
3. V. E. Zakharov, Zh. Eksp. Teor. Fiz. 62, 1745 (1972); [Sov. Phys. JETP 35, 908 (1972)].
4. W. Rozmus, M. Casanova, D. Pesme, A. Heron, and J.-C. Adam, Phys. Fluids B 4, 576 (1992).
5. J. Candy, W. Rozmus, and V. T. Tikhonchuk, Phys. Rev. Lett. 65, 1889 (1990).
6. B. I. Cohen, B. F. Lasinski, A. B. Langdon, and E. A. Williams, Phys. Plasmas 4, 956 (1997). The more general type of linearized hydrodynamic response, which allows for finite ion pressure contributions, involves another parameter. See D. R. Nicholson, Introduction to Plasma Theory (Wiley, New York, 1983), p. 179.
7. B. I. Cohen, B. F. Lasinski, A. B. Langdon, and E. A. Williams, Phys. Plasmas 4, 956 (1997). The more general type of linearized hydrodynamic response, which allows for finite ion pressure contributions, involves another parameter. See D. R. Nicholson, Introduction to Plasma Theory (Wiley, New York, 1983), p. 179.
8. L is the Langmuir wave momentum density.
9. eff independent ζs, weakening the solution's dependence on the detailed statistics of ζ.
10. W. W. Wood, Fundamental Problems in Statistical Mechanics, edited by E. D. G. Cohen (North-Holland, Amsterdam, The Netherlands, 1975). Vol. 3, p. 334.
11. This terminology is borrowed from fluid turbulence. As Eq. (1) may be derived from the electron momentum equation (along with the continuity and Poisson's equations), if damping is negligible for a certain range of length scales, then all that is left is inertia as expressed by momentum transport.
12. D. A. Russell, D. F. DuBois, and H. A. Rose, "Nonlinear saturation of stimulated Raman scattering in laser hot spots," submitted to Phys. Plasmas.
13. Exact means in so far as the statistical properties of the solution are concerned, and of course it is only "exact" to the extent that the random number generator used to obtain the time series of S is exact.
14. J. C. Bowman, B. A. Shadwick, and P. J. Morrison, "On exactly conservative integrators," to appear in Modeling and Applied Mathematics, 15th IMACS World Congress on Scientific Computation, August 1997 (also available from the University of Texas at Austin, IFSR # 791).
15. Only density conservation survives in this model, and by convention initial conditions are constrained so that the spatial average of δn vanishes.
16. D. F. DuBois (private communication, 1998).
17. y.
18. D. A. Russell, D. F. DuBois, and H. A. Rose, Phys. Rev. Lett. 60, 581 (1988).
19. D. Russell, D. F. DuBois, and H. A. Rose, Phys. Rev. Lett. 60, 581 (1988).
20. D. F. DuBois, H. A. Rose, and D. A. Russell, Phys. Scr. T30, 137 (1990).
21. x=4π.
22. If the simulation region is too short, then the density spectrum may peak at k = dk. In such a case it has sometimes been found that qualitative changes in the turbulent state may be obtained by lengthening the system. Simulations suggest that small acoustic damping coefficients lead to longer wavelength density fluctuations, and hence the simulation region was doubled to resolved the density spectrum peak at small k.
23. B. Bezzerides, D. F. DuBois, and H. A. Rose, Phys. Rev. Lett. 70, 2569 (1993).
24. T. Kolber, W. Rozmus, and V. T. Tikhonchuk, Phys. Fluids B 5, 138 (1993).
25. E goes to zero forces the scaling exponent η=3. Reference 23 has proposed a scaling relation which is equivalent [see its Eq. (22)].
26. In such a regime, the model of J. A. Heikkinen and S. J. Karttunen, Phys. Fluids 29, 1291 (1986), may be useful.
27. y, and whose associated wavelength is only limited by the system size in the "y" direction. This provides a finite correlation length, so that the mesoscale ansatz has a chance.
28. This would also imply a re-evaluation of an effective LDl threshold.