TJ-II:Interferometry
TJ-II has two interferometry systems.
The Microwave interferometer
The probing beam has a frequency of 140 GHz, corresponding to a wavelength of = 2.14 mm. The diagnostic provides a time trace of the-line integrated electron density (65536 points, sampling rate 100 kHz). The signal is less reliable for high densities (above ). This time trace is fundamental for machine operation.
The CO2 interferometer
The probing wavelength is about .