Three-wave scattering in magnetized plasmas: From cold fluid to quantized Lagrangian
Large amplitude waves in magnetized plasmas, generated either by external pumps or internal instabilities, can scatter via three-wave interactions. While three-wave scattering is well known in collimated geometry, what happens when waves propagate at angles with one another in magnetized plasmas remains largely unknown, mainly due to the analytical difficulty of this problem. In this study, we overcome this analytical difficulty and find a convenient formula for three-wave coupling coefficient in cold, uniform, magnetized, and collisionless plasmas in the most general geometry. This is achieved by systematically solving the fluid-Maxwell model to second order using a multiscale perturbative expansion. The general formula for the coupling coefficient becomes transparent when we reformulate it as the scattering matrix element of a quantized Lagrangian. Using the quantized Lagrangian, it is possible to bypass the perturbative solution and directly obtain the nonlinear coupling coefficient from the linear response of the plasma. To illustrate how to evaluate the cold coupling coefficient, we give a set of examples where the participating waves are either quasitransverse or quasilongitudinal. In these examples, we determine the angular dependence of three-wave scattering, and demonstrate that backscattering is not necessarily the strongest scattering channel in magnetized plasmas, in contrast to what happens in unmagnetized plasmas. Finally, our approach gives a more complete picture, beyond the simple collimated geometry, of how injected waves can decay in magnetic confinement devices, as well as how lasers can be scattered in magnetized plasma targets.
- Research Organization:
- Princeton Univ., NJ (United States); Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- NA0002948; AC02-09CH11466
- OSTI ID:
- 1378090
- Alternate ID(s):
- OSTI ID: 1374944
- Journal Information:
- Physical Review E, Vol. 96, Issue 2; ISSN 2470-0045
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Laser-plasma interactions in magnetized environment
|
journal | May 2018 |
Amplification of mid-infrared lasers via backscattering in magnetized plasmas
|
journal | July 2019 |
| Laser Amplification in Strongly-Magnetized Plasma | text | January 2018 |
| Three-wave interactions in magnetized warm-fluid plasmas: general theory with evaluable coupling coefficient | text | January 2019 |
Similar Records
Three-wave interactions in magnetized warm-fluid plasmas: General theory with evaluable coupling coefficient
Analytical solutions to the general problem of oblique wave growth and damping