Introduction to Inertial Confinement Fusion by laser
Inertial Confinement is an approach to Controlled Thermonuclear Fusion which relies on the implosion (compression and heating) of a small quantity of fuel (deuterium and tritium) by energetic laser beams. Currently, the most advanced experiments are conducted at the National Ignition Facility, a Megajoule laser system installed at the Lawrence Livermore National Laboratory in the US. This follows the so-called indirect-drive scheme, where the laser beams are focused inside a cavity (hohlraum) and converted to soft X-rays which produced the implosion fo the fuel placed inside the hohlraum.
In contrast, in the direct-drive approach, the laser beams produce the implosion directly. This is investigated in several facilities, first of all, the laser Omega at the University of Rochester in the US. Several other big facilities (LMJ in France, SH III in China) and intermediate facilities (Gekko in Japan, PASL in Prague, Phelix in Germany, Orion in the UK, etc.) allows studying the implosion process or the Physics related to inertial fusion.
The lecture will describe in particular:
- Principles of laser-fusion
- Direct and indirect laser-drive
- Big laser facilities
- The principle of hot spot central ignition
- The rocket model of laser-driven implosions
- Energy-balance in the target
- Hydrodynamics instabilities
- NIF results: National Ignition Campaign
- NIF results: High-foot implosions and recent experiments
- Alternative approaches: Fast ignition
- Alternative approaches: shock ignition
- Perspective for future