Publication Type
Journal
Journal Name
Nuclear Fusion
Publication Date
Page Numbers
1081 to 1086
Volume
41
Issue
8
Abstract
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 agreement
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.