Title :
High-current plasma lens
Author :
Goncharov, A.A. ; Dobrovolsky, A.N. ; Zatuagan, A.V. ; Protsenko, I.M.
Author_Institution :
Inst. of Phys., Acad. of Sci., Kiev, Ukraine
fDate :
10/1/1993 12:00:00 AM
Abstract :
The static and dynamic characteristics of a high-current plasma lens (PL) with a two-component quasi-neutral plasma medium formed by a wide-aperture, repetitively pulsed ion beam and secondary electron emission are investigated experimentally. Such a system provides magnetic isolation of electrons and ion beam focusing by means of electric fields due to uncompensated space charge. It is shown that careful selection of the magnetic field geometry, the number of lens electrodes, and the external potential distribution applied to them according to theoretical plasma optics principles allows the radial electric potential within the PL volume to be tailored to widely varying profiles. It is shown that there is a significant influence of the ion beam itself on the potential shape. Lens collective processes due to nonremovable radial gradients of the magnetic field in the ion beam focusing direction are investigated. It is shown that the conductivity mechanism and lens electrode leakage are connected with observed small-scale turbulence. A theoretical analysis of the linear growth phase of an instability is presented, and estimates are made of the nonlinear variable potential amplitude
Keywords :
beam handling equipment; focusing; ion beams; ion optics; plasma devices; space charge; collective processes; conductivity mechanism; dynamic characteristics; electric fields; external potential distribution; high-current plasma lens; instability; ion beam; ion beam focusing; lens electrode leakage; lens electrodes; magnetic field geometry; magnetic isolation; nonlinear variable potential amplitude; plasma optics principles; potential shape; radial electric potential; repetitively pulsed ion beam; secondary electron emission; small-scale turbulence; space charge; static characteristics; two-component quasi-neutral plasma medium; Electrodes; Electron beams; Electron emission; Geometrical optics; Ion beams; Lenses; Magnetic fields; Magnetosphere; Plasma properties; Space charge;
Journal_Title :
Plasma Science, IEEE Transactions on
