Active beam spectroscopy for ITER
Nuclear Instruments and Methods in Physics Research Section A : Accelerators, Spectrometers, Detectors and Associated Equipment
The latest status of 'Active Beam' related spectroscopy aspects as part of the ITER diagnostic scenario is presented. A key issue of the proposed scheme is the ultimate goal of achieving global data consistency. This implies that all particles involved, that is, intrinsic and seeded impurity ions well as helium ash ions and bulk plasma ions and also the plasma background data (e.g. magnetic and electric fields, electron density and temperature profiles) need to be addressed (cf ). A further
... ensible step in this direction is the decision of exploiting both a dedicated low-energy, low-power diagnostic beam (DNB, 2.2MW 100 keV/amu) as well as the high-power, high-energy heating beams (HNB, 17MW 500keV/amu) for maximum diagnostic information. The feasibility study encompasses CXRS (Charge Exchange Recombination Spectroscopy) for the measurement of the main impurity ion densities (including helium ash), ion temperatures and toroidal and poloidal plasma rotation. Beam Emission Spectroscopy (BES) is proposed as indispensable crosscalibration tool for absolute local impurity density measurements  and also for the continuous monitoring of the neutral beam power deposition profile. Fluctuation measurements based on BES are considered for the plasma edge . Finally, a full exploitation of the 'Motional Stark Effect' pattern is proposed to deduce pitch angles, radial electric fields and total magnetic fields [4,5,6].