Non-inductive current generation in NSTX using coaxial helicity injection

摘要

Coaxial helicity injection (CHI) on the National Spherical Torus Experiment(NSTX) has produced 240 kA of toroidal current without the use of the central solenoid. Values of the current multiplication ratio (CHI produced toroidal current/injector current)up to 10 were obtained, in agree- ment with predictions. The discharges, which lasted for up to 200 ms, limited only by the programmed waveform, are more than an order of magnitude longer in duration than any CHI discharges previously produced in a spheromak or a spherical torus.