Coaxial helicity injection has been investigated on the National SphericalTorus Experiment (NSTX). Initial experiments produced 130 kA of toroidalcurrent without the use of the central solenoid. The corresponding injectorcurrent was 20 kA. Discharges with pulse lengths up to 130 ms have beenproduced.
Experimental demonstration of tokamak inductive flux saving by transient coaxial helicity injection on national spherical torus experiment