Electrostatic Plugging of Multidipole Cusps.
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
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Electrostatic plugging of multidipole cusps is investigated. The plugging is produced by placing positively biased electrodes on both sides of all magnetic cusps. Experimental observations show the plasma potential follows the electrode potential and the plasma electron density increases by a factor of about two as the electrode bias increases from zero. The addition of a negatively biased grid at one end of the chamber does not change the response of the plasma electron density to the electrode bias. A model, which considers plasma losses along the magnetic cusps as well as by diffusion transverse to the field lines, is shown to qualitatively agree with the data. The elevated interior plasma potential permits the identification and investigation of secondary electron production at the walls. Data is presented which shows that secondary electron emission rate at the chamber walls can be comparable to plasma production rate. A measurement of the relative ion densities of Hydrogen is attempted, but the results are inconclusive as to the effect improved confinement has on the various ion species densities. Author
- Numerical Mathematics
- Plasma Physics and Magnetohydrodynamics