Hot Electron Generation And Spatial Energy Deposition By Infrared Laser At Shock Ignition Relevant Intensity

Understanding hot electron generation and their spatial energy deposition in high density target are important for shock ignition (SI), an alternative inertial confinement fusion (ICF) concept achieving ignition by a strong converging shock launched by a high intensity laser spike. In recent experiments, moderately energetic (¡100 keV) hot electrons generated by OMEGA-60 UV lasers enhanced the ablation pressure by 30%
¹
. Shock ignition with longer wavelength lasers was also proposed and discussed in theory
²
. We have performed a series of experiments in both planer geometry with kilojoule scale OMEGA-EP lasers and spherical geometry with joint OMEGA-60/OMEGA-EP lasers to investigate hot electron generation and spatial energy deposition as the result of IR beam (2.6 kJ, 100 ps, intensity up to 10
¹⁷
Wcm
^-2
) interaction with SI-relevant long scalelength hot plasmas (1–3 keV, up to $450 \mu \mathrm {m})$.