Progress toward a microsecond duration, repetitive, intense-ion beam for active spectroscopic measurements on ITER

摘要

The authors describe the design of an intense, pulsed, repetitive, neutral beam based on magnetically insulated diode technology for injection into ITER for spectroscopic measurements of thermalizing alpha particle and thermal helium density profiles, ion temperature, plasma rotation, and low Z impurity concentrations in the confinement region. The beam is being developed to enhance low signal-to-noise ratios expected with conventional steady-state ion beams because of severe beam attenuation and intense bremstrahlung emission. A 5 GW (e.g., 100 keV, 50 kA) one-microsecond-duration beam would increase the signal by 10(sup 3) compared to a conventional 5 MW beam with signal-to-noise ratios comparable to those from a chopped conventional beam in one second.