TOROIDAL PLASMA CONTAINMENT WITH ROTATING MAGNETIC FIELD.
Abstract
Experimental investigations were conducted on a toroidal plasma with alternating pinch- and theta-pinch magnetic fields as well as with a theta-pinch and with a screw pinch. For the alternating pinch, the resultant magnetic vector is rotating, so that there are no periodic zeros in the containing magnetic pressure, and containment times for high-plasmas may possibly be extended beyond one half cycle. Also, for field rotation frequencies much smaller than the electron collision frequency, shear occurs in the magnetic field through the skin of the plasma, thereby improving the plasma stability. If the current sheet thickness measured from the oscillograms is taken as skin depth, Suydam's necessary condition for stability of a linear pinch with a rotating magnetic field is not satisfied in our experiments. The 'fanning' effect occurring right after the plasma compression in the second half cycle in toroidal theta-pinches is quenched by the rotating field, but plasma conditions for the theta-pinch and for the alternating pinch are not comparable on account of the inhibiting effect of the pinch magnetic field on the ionization caused by the theta-pinch field. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1966
- Accession Number
- AD0632379
Entities
People
- Donald E. Brown
- H. G. Loos