Patent Number: 052251462
Section: claims

1. A method of improving confinement properties of a plasma of a tokamak having a toroidal magnetic field direction comprising: (a) providing a ripple field region in the plasma;  (b) injecting electrons having predominantly perpendicular energy with respect to the toroidal magnetic field direction of the plasma into the ripple field region for trapping the electrons into the plasma; and,  (c) negatively charging the plasma center with respect to the edge by allowing the electrons to grad-B drift vertically toward the plasma interior until they are detrapped, thereby creating a radial electric field at the edge of the plasma.  (a) an external cathode adjacent to the tokamak for emitting electrons into the plasma;  (b) means for accelerating the electrons by radiofrequency waves at the electron cyclotron frequency;  (c) a plurality of magnetic coils located around the torus of the tokamak creating a local magnetic field ripple for trapping the electrons;  whereby the electrons drift and move toward the interior of the plasma until they are detrapped, thereby creating a radial electric field at the edge of the plasma. 2. The method of claim 1 wherein the electrons are injected from an electron source exterior of the plasma. 3. The method of claim 2 wherein the electrons are injected by a flat cathode containing an electrocyclotron-heating cavity. 4. The method of claim 3 wherein the trapping of electrons in the plasma is governed by: EQU v.sub..perp. v.sub..vertline. .gtoreq.(2.delta.).sup.1/2 5. The method of claim 4 wherein the ripple field is created by poloidal bending magnets locally placed around the torus of the takamak. 6. The method of claim 5 wherein the cathode has an electron emitting faceplate of LaB.sub.6. 7. An electron injector for improving confinement properties in a tokamak plasma direction comprising: 8. The electron injector of claim 7 wherein the means for accelerating the electrons by radio frequency waves includes an electro cyclotron heating waveguide cavity and an electro cyclotron heating acceleration region adjacent to the cathode. 9. The electron injector of claim 8 wherein the electrode includes a carbon heater and an electron emitting faceplate of LaB.sub.6.