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About the modeling of light beam self-focusing in plasma at the irradiation of the target by power UV laser

https://doi.org/10.32362/2500-316X-2021-9-1-79-86

Abstract

The peculiarities of light beam expansion in plasma upon irradiation of condensed targets with a powerful UV laser pulse are studied with the help of mathematical modeling. Experiments were carried out at the Lebedev Physical Institute of the Russian Academy of Sciences with the use of GARPUN installation: a powerful KrF laser that irradiated two-layer targets consisting of aluminum foil and a plexiglass layer. Channels stretched along the direction of incidence of the laser beam were found at the bottom of the crater. It was shown on the basis of experimental and calculated data that selffocusing of the laser beam developed in the plasma. As a result, hot spots were produced in vicinity of the plasma critical density, and fast (superthermal) electron flows were generated. The electron flows could produce the channels in the plexiglas. In order to describe the self-focusing effect a physicalmathematical model was developed, and “FOCUS” program was created at the Russian Technological University (MIREA). Numerical simulations were carried out on the gas-dynamic profiles (linear and exponential). It was shown that thermal self-focusing could develop at the conditions of “GARPUN” experiments (~ 1 mm longitudinal plasma, moderate radiation intensity: 1011–1012(W/cm2) × µm2).  The parameters of dangerous modes of laser beam perturbations were estimated. The interest in the experimental and mathematical modelling results is related to the laser thermonuclear fusion (LTF) research. Although Nd glass lasers are the basic installations for LTF research, UV gas eximer lasers have some advantages as drivers for future thermonuclear fusion reactors. The interaction of UV laser radiation with plasma has some peculiarities. Thus, developing physical-mathematical models and creating new programs required for the interpretation of modern UV laser – plasma coupling experiments and for the design of large scale facilities based on eximer drivers is a topical problem.

About the Author

I. G. Lebo
MIREA – Russian Technological University
Russian Federation

Ivan G. Lebo,Dr. Sci. (Physics and Mathematics), Professor of Department of Higher Mathematics, Cybernetics Institute

78, Vernadskogo pr., Moscow 119454

Scopus Author Id 7003412908



References

1. Basov N.G., Krokhin O.N. Conditions for heating up of a plasma by the radiation from an optical generator. Sov. Phys. JETP.1964;19(1):123–126. URL: http://www.jetp.ac.ru/cgi-bin/dn/e_019_01_0123.pdf

2. Moses E.I. and the NIC Collaborators. The National Ignition Compaign: status and progress. IOP Publishing and International Atomic Energy Agency. Nuclear Fusion. 2013;53(10):104020. https://doi.org/10.1088/0029-5515/53/10/104020

3. Garanin S.G., Bel’kov S.A., Bondarenko S.V. In: Proc. XXXIX Intern. (Zvenigorod) conf. on plasma phys. and controlled fusion. Russia, Zvenigorod, 6–10 February, 2012. P. 17 (in Russ.).

4. Ebrardt J. and Chapt J.M. LMJ on its way to fusion. J. Phys.: Conf. Ser.2010;244(3):032017. https://doi.org/10.1088/1742-6596/244/3/032017

5. Zhen W., Wei X., Zhu Q., Jing F. et al. Laser performance of the SG-III laser facility. High Power Laser. Sci Eng. 2016;4:e21. https://doi.org/10.1017/hpl.2016.20

6. Smalyuk V.A., Robey H., Döppner T., Casey D.N. et al. Experimental results of radiation-driven, layered deuteriumtritium implosions with adiabat-shaped drives at the National Ignition Facility. Phys. Plasmas.2016;23(10):101063. https://doi.org/10.1063/1.4964919

7. Basov N.G., Lebo I.G., Rozanov V.B. Fizika lazernogo termoyadernogo sinteza (Physics of Laser Thermonuclear Fusion). Moscow: Znanie; 1988. 172 p. (in Russ.).

8. Kuzenov V.V., Lebo A.I., Lebo I.G., Ryzhkov S.V. Fizikomatematicheskie modeli rascheta vozdeistviya moshchnykh lazernykh i plazmennykh potokov(Physical-mathematical models and simulation methods of action of high-power). Moscow: N.E. Bauman Moscow State Technical University Publishing House; 2015. 326 p. (in Russ.). ISBN 978-5-7038-4183-9

9. Bodner S.E. The path to electrical energy using laser fusion. High Power Laser Sci. Eng.2019;7:e63. https://doi.org/10.1017/hpl.2019.51

10. Zvorykin V., Lebo I., Shutov A., Ustinovskii N. Selffocusing of UV radiation in 1 mm scale plasma in a deep ablative crater produced by 100 ns, 1 GW KrF laser pulse in the context of the ICF. Matter Radiat. Extremes.2020;5(3):03540. https://doi.org/10.1063/1.5142361

11. Askar’yan G.А. Effect of the gradient of a strong electromagnetic beam on electrons and atoms. Sov. Phys. JETP. 1962;15:1088.

12. Akhmanov S.A., Sukhorukov A.P., Khohlov R.V. Self-focusing and diffraction of light in nonlinear medium. Sov. Phys. Usp.1968;10:609–636. https://doi.org/10.1070/PU1968v010n05ABEH005849

13. Sodha M.S., Tripathi V.K. Nonlinear penetration of an inhomogeneous laser beam in an overdense plasma. Phys. Rev. A.1977;16(5):2101–2104. https://doi.org/10.1103/PhysRevA.16.2101

14. Zvorykin V.D., Lebo I.G. Laser and Target Experiments on KrF GARPUN laser installation at FIAN. Laser Part. Beams. 1999;17(1):69–88. https://doi.org/10.1017/S0263034699171064

15. Craxton R.S., Anderson K.S., Boehly T.R. et al. Direct-drive inertial confinement fusion: A review. Phys. Plasmas.2015;22(11):110501. https://doi.org/10.1063/1.4934714

16. Ginzburg V.L. Rasprostranenie elektromagnitnykh voln v plazme (Propagation of electromagnetic waves in plasma). Moscow: Nauka; 1967. 683 p. (in Russ.). [Ginzburg V.L. Propagation of the Electromagnetic Waves in Plasmas: Transl. from the Russian. (Eds.) W.L. Sadowski and D.M. Gallik. NY: Gordon and Breach; 1961. 822 p.]

17. Born M., Vol'f E.Osnovy optiki(Principles of optics). Моscow: Nauka; 1973. 719 p. (in Russ.).

18. Max C.G. Strong self-focusing due to the ponderomotive force in plasmas. Phys. Fluids.1976;19:74–77. https://doi.org/10.1063/1.861305

19. Perkins F.W., Valeo E.J. Thermal Self-Focusing of Electromagnetic Waves in Plasmas. Phys. Rev. Letters. 1974;32(22):1234–1237. https://doi.org/10.1103/PhysRevLett.32.1234

20. Lebo I.G., Simakov A.I. Modeling the evolution of whirl structures in a supersonic gas stream. Rossiiskii tekhnologicheskii zhurnal = Russian Technological Journal. 2018;6(5):45–54 (in Russ.). https://doi.org/10.32362/2500-316X-2018-6-5-45-54


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The peculiarities of light beam expansion in plasma upon irradiation of condensed targets with a powerful UV laser pulse are studied with the help of mathematical modeling. It was shown on the basis of experimental and calculated data that selffocusing of the laser beam developed in the plasma. As a result, hot spots were produced in vicinity of the plasma critical density, and fast (superthermal) electron flows were generated. The parameters of dangerous modes of laser beam perturbations were estimated.

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Lebo I.G. About the modeling of light beam self-focusing in plasma at the irradiation of the target by power UV laser. Russian Technological Journal. 2021;9(1):79-86. (In Russ.) https://doi.org/10.32362/2500-316X-2021-9-1-79-86

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