Thomson Scattering Device Calibrated by Rotational Raman Scattering of Hydrogen

The anti-Stokes rotational Raman scattering from gaseous hydrogen at a pressure of 60–200 Torr and 293 K was used to calibrate the intensity of the Thomson signal scattered from the JFT-2M tokamak plasma by the incidence of ruby laser light. The electron temperature and density profiles were calculated through a calibration constant obtained with the Raman scattered light and LED light, and the error in the electron density was found to depend on the uncertainty in the differential Raman cross-section of the hydrogen, the density of the gas, the electron temperature, and the photoelectron statistics.