| 摘要 |
PURPOSE:To make an integrator and an optical telemeter part unnecessary and improve the precision of measurement, by utilizing the optical Farady effect to connect directly an optical fiber cable to a vacuum vessel. CONSTITUTION:The light emitted from a polarizer 12 has the plane of vibration changed by an angle theta because of the optical Farady effect due to a magnetic field phi applied to the coil-shaped part of an optical fiber cable 13. The light from a light emitting element 11 is a kind of electromagnetic wave and has a plane of vibration; and since the optical fiber cable 13 to which vibrating waves passing only at a certain angle are transmitted by the polarizer 12 is coil-shaped in a vacuum vessel 1, a magnetic field is generated when a current due to a plasma current is flowed, and the angle of the plane of vibration of light is affected. This angle theta is expressed by thetaalphaKH when the intensity of the magnetic field is denoted as H and K is a constant, and the angle theta is determined by the position of the plasma. The optical signal whose plane of vibration is shifted at the angle theta is inputted to an analyzer 14, and the light of only horizontal components is taken out, and its optically attenuated light level is detected by a photodetector 15 and is inputted to a recorder 16, thereby measuring the pertinent plasma current. |
