Laser plasma instability in indirect-drive inertial confinement fusion

Abstract

In indirect-drive inertial confinement fusion (ICF), the incident laser beam could excite laser plasma instabilities (LPI) such as stimulated Brillouin scattering (SBS), stimulated Raman scattering (SRS) and two plasmon decay (TPD) besides gently heat the hohlraum through collisional absorption. These instabilities would largely reduce the X-ray conversion and degrade the drive symmetry of the radiation environment. In addition, when the amplitude of parametric instability increases to a certain level, there would be interplay between different instabilities, which makes LPI complicated and unpredictable. Therefore, LPI has become one of the major challenge in achieving ignition. LPI research during recent few years made great strides in identifying, understanding, and controlling instabilities in the context of laser fusion. This paper reviews the progress in this important field according to laser (L), plasma (P), and instability (I). Prospects for the application of our improved understanding for indirect drive ICF and some exciting research opportunities are also discussed.

Simulation analysis of polarization smoothing based on full Poincaré beam modulated by single transmission element

“…In the laser-driven inertial confinement fusion (ICF) facilities, the beams pass through dozens of meters of light paths and dozens of optical elements, it is modulated by various disturbances and uneven gains, so when they are focused on the target area, the energy distribution of the focal spots will be uneven 1 , which will lead to complex laser plasma instabilities (LPI) in the target area 2,3 . LPI is harmful to fusion ignition, it will cause backscattering and reduce the energy utilization, and due to its non-uniform and unstable characteristics, it will destroy the symmetrical compression of the fuel, and it will also generate thermionics through Landau damping, preheat the fuel so that it cannot be compressed efficiently 4 . With the development of high-power laser facilities, LPI has become the key to the success of fusion ignition.…”