TJ-II:Diagnostic neutral beam
TJ-II has a compact diagnostic neutral beam injector, designed for performing spatially resolved charge exchange recombination spectroscopy and neutral particle analysis measurements. It is located in sector A7 and it is currently employed to obtain radial profiles of impurity ion (carbon) temperature and velocity. [1] The injector, an upgraded DINA-5 model, is supported on a mobile cradle that permits its path through the plasma to be varied by ±3° poloidally. In parallel, a dedicated bidirectional (two vertical opposing views) multichannel spectroscopic diagnostic, incorporating fiber arrays, an f/1.8 spectrograph, and a back-illuminated charge-coupled device, has been installed to obtain Doppler line shifts and widths (around 529.2 nm) with ~1 cm spatial resolution. [2]