Measurement of Plasma Density in Modern Fusion Devices by Dispersion Interferometer

We propose to use dispersion interferometer for measurement of plasma density and control of plasma position on present and future fusion devices. Distinguishing feature of this scheme is probing of plasma on two wavelengths. Short-wave radiation is formed by method of frequency fundamental radiation doubling. Probing first and second harmonics rays are combined spatially at the same time. It allows to create interferometer which is sensitive only to dispersion of studied medium and weakly sensitive to vibration of optical elements. Designs of the optical system dispersion interferometer and results of plasma density measurements on GDT mirror and TEXTOR tokamak are presented.