IMPROVEMENT OF INTERFEROMETRIC MEASUREMENTS ON FAR-INFRARED POLARIMETER INTERFEROMETER SYSTEMS

On many tokamaks the reconstruction of the magnetic field structure in the plasma is supported by polarimetric measurements. Recent proposed and realized methods are based on a far-infrared laser beam with a ro tating polarization ellipse. The same instrument usually performs as a n interferometer measuring the line integrated plasma density. It has been shown that the rotating polarization ellipse disturbs the interfe rometric measurements. A method based on the principle of a rotating p olarization in which the interferometric measurement is unaffected is proposed. Bench test results are presented which show the feasibility of this method. (C) 1996 American Institute of Physics.