A Perspective Self-Generated Magnetic Fields.
NAVAL RESEARCH LAB WASHINGTON D C
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Self-generated magnetic fields in the megagauss range have recently been re-confirmed by Faraday rotation diagnostics of laser-plasma coupling. These fields, through their inhibition on thermal transport, could have an important effect in pellet design. There has been impressive progress over the last decade, both experimentally and theoretically, toward understanding the physics of the magnetic fields. The newer results can be seen in the historical perspective of the many past contributions described in the published literature. Direct experimental studies have utilized both physical probes coils and Faraday rotation of a polarized, probing laser beam. Experimental x-ray studies have also provided indirect evidence for the fields by requiring thermal transport inhibition in a self-consistent 2-D numerical modelling of the laser-plasma interactions. The rich variety of theoretical studies includes magnetic field effects in ordinary and magnetic resonant absorption. A 3-channel diagnostic system, utilizing Faraday rotation of a Raman-shifted beam, has allowed a study of the magnetic field dependence on several experimental conditions-particularly timing and the presence of a pre-formed plasma. Future work includes determining the importance of the fields at the lower irradiances now under consideration for pellets, and measuring the fields in the critical region where resonant absorption and radiative forces are important. Author
- Electricity and Magnetism
- Plasma Physics and Magnetohydrodynamics