FIR Laser Interferometer

Measurement of line integrated electron density
Stationary work for real time density feed back

[Detectors, Diagnostic Method]
Laser: CH3OH 118.8mm CW optically pumped by CO2 laser
Interferometer: Off axis Michelson, Vibration compensation by HeNe interferometer
Detector:Liq.He cooled GeGa
Phase discriminator: 2MHz,1/100Fringe resolution by 200MHz clock

Time resolution: 5 ms
Spatial resolution: Vertical 2 chodes (U1 & U2)
Line density resolution: 0.94x1017 m-2
Position:P-16 section U1 & U2

T.Fukuda and A.Nagashima, "Frequency stabilized single mode cw 118.8mm CH3OH waveguide laser for large tokamak diagnostics" Rev.Sci.Instrum.60(6),June,1989