摘要
Processes of laser energy absorption and electron heating in an expanding plasma in the range of irradiances Iλ^2=1015–1016 W·μm^2/cm^2 are studied with the aid of kinetic simulations.The results show a strong reflection due to stimulated Brillouin scattering and a significant collisionless absorption related to stimulated Raman scattering near and below the quarter critical density.Also presented are parametric decay instability and resonant excitation of plasma waves near the critical density.All these processes result in the excitation of high-amplitude electron plasma waves and electron acceleration.The spectrum of scattered radiation is significantly modified by secondary parametric processes,which provide information on the spatial localization of nonlinear absorption and hot electron characteristics.The considered domain of laser and plasma parameters is relevant for the shock ignition scheme of inertial confinement fusion.
Processes of laser energy absorption and electron heating in an expanding plasma in the range of irradiances I λ2=1015–1016 W · μm2/cm2 are studied with the aid of kinetic simulations. The results show a strong reflection due to stimulated Brillouin scattering and a significant collisionless absorption related to stimulated Raman scattering near and below the quarter critical density. Also presented are parametric decay instability and resonant excitation of plasma waves near the critical density. All these processes result in the excitation of high-amplitude electron plasma waves and electron acceleration. The spectrum of scattered radiation is significantly modified by secondary parametric processes, which provide information on the spatial localization of nonlinear absorption and hot electron characteristics. The considered domain of laser and plasma parameters is relevant for the shock ignition scheme of inertial confinement fusion.
基金
funding from the Euratom Research and Training Programme 2014–2018 under grant agreement No. 633053
supported by the project ELITAS (CZ.02.1.01/0.0/0.0/16 013/0001793)
by the project High Field Initiative (CZ.02.1.01/0.0/0.0/15 003/ 0000449)
from the European Regional Development Fund
supported by the project ADONIS (Advanced research using high intensity laser produced photons and particles), CZ.02.1.01/0.0/0.0/16 019/0000789
from the European Regional Development Fund
partially supported by the Center of Advanced Applied Natural Sciences, Reg. No. CZ.02.1.01/0.0/0.0/16 019/0000778
by the Operational Program Research, Development and Education
co-financed by the European Structural and Investment Funds
the state budget of the Czech Republic
