Fusion Science and Technology / Volume 45 / Number 1 / January 2004 / Pages 65-68
Supplemental Paper / Fifteenth Topical Meeting on the Technology of Fusion Energy
In a nuclear fusion experiment device, a plasma discharge is to be sustained for a long time in steady state operation. In such a device an electromagnetic sensor that has a signal integrator to measure direct currents will cause a technical problem of zero point drift on signals. Therefore, the detection device using new technology for direct current measurement, optical current transformer (optical CT), was developed. The device has an optical fiber specified for850 and 1550nm (wavelength) were manufactured, and was applied to current measurement in JT-60U experiments. A gamma ray irradiation examination was also done to the optical CT.