Impact of ion collisions on backscattering competition under the Langdon effect

Zhang Shuqing; Li Xiaoran; Qiu Jie; Hao Liang

doi:10.11884/HPLPB202537.250148

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Zhang Shuqing, Li Xiaoran, Qiu Jie, et al. Impact of ion collisions on backscattering competition under the Langdon effect[J]. High Power Laser and Particle Beams. doi: 10.11884/HPLPB202537.250148

Citation:

Zhang Shuqing, Li Xiaoran, Qiu Jie, et al. Impact of ion collisions on backscattering competition under the Langdon effect[J]. High Power Laser and Particle Beams. doi: 10.11884/HPLPB202537.250148

Zhang Shuqing, Li Xiaoran, Qiu Jie, et al. Impact of ion collisions on backscattering competition under the Langdon effect[J]. High Power Laser and Particle Beams. doi: 10.11884/HPLPB202537.250148

Citation:

Zhang Shuqing, Li Xiaoran, Qiu Jie, et al. Impact of ion collisions on backscattering competition under the Langdon effect[J]. High Power Laser and Particle Beams. doi: 10.11884/HPLPB202537.250148

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Impact of ion collisions on backscattering competition under the Langdon effect

doi: 10.11884/HPLPB202537.250148

Institute of Applied Physics and Computational Mathematics, Beijing 100094, China

Received Date: 2025-03-20
Accepted Date: 2025-06-12
Rev Recd Date: 2025-06-04

Available Online: 2025-10-23

Abstract

Abstract

Background
Backward stimulated Raman scattering (SRS) and backward stimulated Brillouin scattering (SBS) are two major laser-plasma instabilities that influence the laser-target energy coupling efficiency in inertial confinement fusion (ICF). Hot electrons excited by SRS can preheat the fuel. Their nonlinear competition determines the effectiveness of laser-plasma coupling and thus the performance of laser-driven fusion. In realistic laser fusion conditions, the electron distribution often deviates from Maxwellian due to strong laser heating, leading to nonthermal effects such as the Langdon effect. Additionally, ion-ion collisions in multispecies plasmas like CH can alter the damping and dispersion of ion acoustic waves.
Purpose
This study aims to investigate the impact of the Langdon effect and ion-ion collisions on the competition between SRS and SBS in CH plasma, particularly focusing on their respective reflectivities under varying plasma conditions.
Methods
Five-wave coupling equations describing the nonlinear interactions among the pump laser, scattered light, Langmuir wave, and ion acoustic wave were numerically solved. A super-Gaussian electron distribution function was employed to incorporate the Langdon effect, while ion-ion collision effects were included through modifications to the ion susceptibility. The dispersion relations and damping characteristics of both electron plasma waves (EPWs) and ion acoustic waves (IAWs) were analyzed in detail.
Results
The results reveal that the Langdon effect notably reduces Landau damping of EPWs and modifies the dispersion relation of SRS, enhancing its growth rate. Simultaneously, ion-ion collisions increase IAW damping and shift the SBS dispersion curve, weakening its instability. These combined effects lead to a dominance of SRS over SBS at lower electron densities, altering the overall backscattering reflectivity spectrum in laser fusion plasma.
Conclusions
Both the Langdon effect and ion-ion collisions play crucial roles in reshaping the nonlinear dynamics of SRS and SBS. Their influence must be considered in predictive models of laser-plasma interactions. These findings provide insight into optimizing plasma parameters for improved control of backscatter instabilities in inertial confinement fusion experiments.
- laser plasma instability,
- stimulated Raman scattering,
- stimulated Brillouin scattering,
- Langdon effect,
- ion collision

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References(24)

References

[1]	McCrory R L, Meyerhofer D D, Betti R, et al. Progress in direct-drive inertial confinement fusion[J]. Physics of Plasmas, 2008, 15: 055503. doi: 10.1063/1.2837048
[2]	Craxton R S, Anderson K S, Boehly T R, et al. Direct-drive inertial confinement fusion: a review[J]. Physics of Plasmas, 2015, 22: 110501. doi: 10.1063/1.4934714
[3]	Lindl J D, Amendt P, Berger R L, et al. The physics basis for ignition using indirect-drive targets on the National Ignition Facility[J]. Physics of Plasmas, 2004, 11(2): 339-491. doi: 10.1063/1.1578638
[4]	Landen O L, Benedetti R, Bleuel D, et al. Progress in the indirect-drive national ignition campaign[J]. Plasma Physics and Controlled Fusion, 2012, 54: 124026. doi: 10.1088/0741-3335/54/12/124026
[5]	He X T, Li J W, Fan Z F, et al. A hybrid-drive nonisobaric-ignition scheme for inertial confinement fusion[J]. Physics of Plasmas, 2016, 23: 082706. doi: 10.1063/1.4960973
[6]	Tabak M, Clark D S, Hatchett S P, et al. Review of progress in fast ignition[J]. Physics of Plasmas, 2005, 12: 057305. doi: 10.1063/1.1871246
[7]	Zhang F, Cai H B, Zhou W M, et al. Enhanced energy coupling for indirect-drive fast-ignition fusion targets[J]. Nature Physics, 2020, 16(7): 810-814. doi: 10.1038/s41567-020-0878-9
[8]	Zhang J, Wang W M, Yang X H, et al. Double-cone ignition scheme for inertial confinement fusion[J]. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2020, 378: 20200015. doi: 10.1098/rsta.2020.0015
[9]	Kritcher A L, Zylstra A B, Weber C R, et al. Design of the first fusion experiment to achieve target energy gain G> 1[J]. Physical Review E, 2024, 109: 025204. doi: 10.1103/PhysRevE.109.025204
[10]	White R, Kaw P, Pesme D, et al. Absolute parametric instabilities in inhomogeneous plasmas[J]. Nuclear Fusion, 1974, 14(1): 45-51. doi: 10.1088/0029-5515/14/1/007
[11]	Forslund D W, Kindel J M, Lindman E L. Theory of stimulated scattering processes in laser-irradiated plasmas[J]. Physics of Fluids, 1975, 18(8): 1002-1016. doi: 10.1063/1.861248
[12]	Langdon A B. Nonlinear inverse bremsstrahlung and heated-electron distributions[J]. Physical Revoew Letters, 1980, 44(9): 575-579. doi: 10.1103/PhysRevLett.44.575
[13]	Hinkel D E, Rosen M D, Williams E A, et al. Stimulated Raman scatter analyses of experiments conducted at the National Ignition Facility[J]. Physics of Plasmas, 2011, 18: 056312. doi: 10.1063/1.3577836
[14]	Turnbull D, Colaïtis A, Hansen A M, et al. Impact of the Langdon effect on crossed-beam energy transfer[J]. Nature Physics, 2020, 16(2): 181-185. doi: 10.1038/s41567-019-0725-z
[15]	Hao Liang, Qiu Jie, Huo Wenyi. Generation of high intensity speckles in overlapping laser beams[J]. Matter and Radiation at Extremes, 2023, 8: 025903. doi: 10.1063/5.0123585
[16]	Li Xiaoran, Qiu Jie, Zhang Shuqing, et al. Investigation of the Langdon effect on the nonlinear evolution of SBS in Au plasmas[J]. Plasma Physics and Controlled Fusion, 2025, 67: 035018. doi: 10.1088/1361-6587/adb17a
[17]	Chen C, Gong T, Li Z, et al. Implementation of a large-aperture Thomson scattering system for diagnosing driven ion acoustic waves on Shenguang-III prototype laser facility[J]. Journal of Instrumentation, 2022, 17: P05017. doi: 10.1088/1748-0221/17/05/P05017
[18]	Chen Chaoxin, Gong Tao, Li Zhichao, et al. Study of the spatial growth of stimulated Brillouin scattering in a gas-filled Hohlraum via detecting the driven ion acoustic wave[J]. Matter and Radiation at Extremes, 2024, 9: 027601. doi: 10.1063/5.0173023
[19]	Qiu Jie, Hao Liang, Cao Lihua, et al. Investigation of Langdon effect on the stimulated backward Raman and Brillouin scattering[J]. Plasma Physics and Controlled Fusion, 2021, 63: 125021. doi: 10.1088/1361-6587/ac2e5b
[20]	Alaterre P, Matte J P, Lamoureux M. Ionization and recombination rates in non-Maxwellian plasmas[J]. Physical Review A, 1986, 34(2): 1578-1581. doi: 10.1103/PhysRevA.34.1578
[21]	Liu Z, Weng S M, Ma H H, et al. Revisit of electron temperature effect on stimulated Brillouin scattering in homogenous plasma[J]. Physics of Plasmas, 2024, 31: 062101. doi: 10.1063/5.0199533
[22]	Hao L, Liu Z J, Hu X Y, et al. Competition between the stimulated Raman and Brillouin scattering under the strong damping condition[J]. Laser and Particle Beams, 2013, 31(2): 203-209. doi: 10.1017/S0263034613000074
[23]	Tang C L. Saturation and spectral characteristics of the Stokes emission in the stimulated Brillouin process[J]. Journal of Applied Physics, 1966, 37(8): 2945-2955. doi: 10.1063/1.1703144
[24]	Hao Liang, Zhao Yiqing, Yang Dong, et al. Analysis of stimulated Raman backscatter and stimulated Brillouin backscatter in experiments performed on SG-III prototype facility with a spectral analysis code[J]. Physics of Plasmas, 2014, 21: 072705. doi: 10.1063/1.4890019