Cars spectrometer for the isotopic analysis of hydrogen in the fuel circuits of fusion reactors

The paper describes a coherent anti-Stokes Raman scattering (CARS) spectrometer using vibrational transitions in molecules of hydrogen isotopes. Stokes waves in high-pressure protium and deuterium are generated by stimulated Raman scattering. The concentrations of H-2 and D-2 can be determined to within 5% after storing the data for 10 min using the concentration characteristics of the apparatus. The lowest detectable concentration of H-2 and D-2 are 80 ppm and 6%, respectively, the total pressure was 50 torr, and the repetition rate of the measurements was 5 Hz.