LASER DIAGNOSTICS IN CONTROLLED THERMONUCLEAR FUSION
Plasma with magnetic field behaves as a birefringent, optically active medium, propagation perpendicular to the field being purely birefringent, propagation parallel to it, purely optically active. It can be shown that for any direction of propagation there exist two characteristic waves with different phase velocities whose state of polarization remains unchanged during propagation, and the characteristic polarizations are orthogonal. A beam propagating in arbitrary direction can be resolved into two characteristic components, which will travel at different phase velocities determined by the corresponding characteristic refractive indexes, then recombine to produce an altered polarization and phase relative to a second beam that traversed the same distance of empty space. This is the basis of the Faraday rotation method for measuring magnetic field, and of interferometry designed to measure plasma electron density. It is also, though less obviously, the process underlying Thomson scattering. The present article is devoted to a short account of these three topics.
Bibliographic Reference: WRITE TO THE LIBRARIAN, UKAEA, CULHAM LABORATORY, ABINGDON, OXON, OX14 3DB (UK) MENTIONING REPORT CLM-P 675, 1982
Record Number: 1989122040300 / Last updated on: 1987-01-01
Available languages: en