Toroidal interferometer/polarimeter density measurement system on ITER

Kondoh, Takashi; Costley, A. E.*; Sugie, Tatsuo; Kawano, Yasunori; Malaquias, A.*; Walker, C. I.*

In order to measure the line average electron density on ITER, a CO laser interferometer/polarimeter system is being developed. The design of the interferometer/polarimeter is improved from the previous design, which uses CO and CO laser, on the basis of experience gained with a dual CO system on JT-60U in which good reliability was confirmed for both interferometry and polarimetry operation. The performance of the dual CO laser meets requirements for ITER (accuracy; 1%, time resolution; 1 ms).