Singlechannel HCN laser interferometer for electron density measurement on the IR-T1 tokamak

Summary form only given. Interferometry os a standard technique for measuring the line integrated electron density of magnetically confined plasma. It is on the basis on the fact that an electromagnetic wave, on its passage through a plasma, experiences a phase change with respect to the reference beam. A single channel far-infrared (FIR) hydrogen cyanide (HCN) laser interferometer was developed to measure plasma electron density on the IR-T1 tokamak. The structure of the single channel FIR laser interferometer is described. The laser source used in the interferometer was a continuous-wave glow discharge HCN laser with a cavity length of 2 m and power output of about 50 mW at 377 /spl mu/m. This system we used from a heterodyne laser interferometer.