Laser Faraday rotation measurement of current density fluctuations and electromagnetic torque (invited)
نویسندگان
چکیده
Far-infrared laser polarimetry with time response up to ,1 ms and spatial resolution ,8 cm has been successfully implemented on the Madison Symmetric Torus reversed-field pinch. Internal magnetic field and current density fluctuations are nonperturbatively measured. This is accomplished by taking parallel polarimetry chords which measure the line-integrated magnetic field fluctuations via Faraday rotation. With suitable analysis we are able to obtain information on spatial profiles of magnetic field fluctuations and current density fluctuations. Coherent interaction between these fluctuations is also measured and observed to generate an electromagnetic fluctuation-induced torque kdJ3dBl. © 2004 American Institute of Physics. [DOI: 10.1063/1.1785275]
منابع مشابه
Laser polarimetric measurement of equilibrium and fluctuating magnetic fields in a reversed field pinch „invited..
New developments in Faraday rotation polarimetry have provided the first measurements of current density profile and core magnetic fluctuations in the core of a high-temperature reversed field pinch. This has been achieved by a fast-polarimeter system with time response up to 1 ms and phase resolution ,1 mrad. Recent experiments on Madison Symmetric Torus have directly measured radial magnetic ...
متن کاملFizeau interferometer for measurement of plasma electron current
A high-resolution, vertically viewing far-infrared polarimeter-interferometer system is currently used on the Madison symmetric torus (MST) reversed-field pinch (RFP) to measure the plasma electron density and toroidal current density via Faraday rotation. In this article, we propose a scheme to measure the well-known Fizeau effect, whereby through modest modification of the existing apparatus,...
متن کاملخواص نوری- مغناطیسی و ضرایب اپتیکی لایههای نازک منگنز-کبالت
Having precise hysterics loop of thin ferroelectric and ferromagnetic layers for optical switching and optical storages are important. A hysterieses loop can be achieved from a phenomenon call the magneto-optic effect. The magneto-optic effect is the rotation of a linear polarized electromagnetic wave propagated through a ferromagnetic medium. When light is transmitted through a layer of magnet...
متن کاملFaraday rotation as a density diagnostic for helical axis stellarators
It is shown that the Faraday ratation of a linexly polarized electromagnetic wave probing a helicalaxis-stellamtor plasma is a useful electron density diagnostic. The twisted magnetic geometry results in a large magnetic field component in the vettinl plane that is asumed to contain the probe beam(s). As a result, significant polarization rotations result for far-infrared beams traversing plasm...
متن کاملFaraday-effect polarimeter-interferometer system for current density measurement on EAST.
A multichannel far-infrared laser-based POlarimeter-INTerferometer (POINT) system utilizing the three-wave technique is under development for current density and electron density profile measurements in the EAST tokamak. Novel molybdenum retro-reflectors are mounted in the inside wall for the double-pass optical arrangement. A Digital Phase Detector with 250 kHz bandwidth, which will provide re...
متن کامل