Electron source with a multi-apertured plasma emitter

12th International Conference on Gas Discharge Plasmas and Their Applications

Vorobyov, M.S.^1,2 ; Koval, N.N.^1,2 ; Sulakshin, S.A.^1

Institute of High Current Electronics SB RAS, 2/3 Akademichesky Ave., Tomsk

634055, Russia^1

National Research Tomsk State University, 36 Lenin Ave., Tomsk

634050, Russia^2

关键词: Accelerating voltages;    Acceleration gap;    Current extraction;    High voltage power supply;    Multi aperture;    Plasma boundary;    Plasma emitters;    Thin metal foil;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/652/1/012067/pdf
DOI  :  10.1088/1742-6596/652/1/012067

来源: IOP

【 摘 要 】

In the present study, we investigated the energy efficiency of an electron source with a multi-aperture plasma emitter where the generated beam is extracted into the atmosphere through a thin metal foil. The boundary of the plasma produced in this type of emitter is stabilized with a fine metal grid. To prevent the loss of electrons at the circle-holed support grid of the extraction foil window, a metal mask with holes of smaller diameter arranged coaxially to the support grid holes is put on the emission grid. Thus, the electron beam is a superposition of beamlets formed by individual electron emitting units with the plasma boundary stabilized by the fine metal grid. The efficiency of current extraction from the acceleration gap into the atmosphere reached 75% with respect to the gap current, making possible to increase the average power of the extracted electron beam. With a 200 -kV accelerating voltage, a 16-A current in the acceleration gap, and 40 μs FWHM pulse duration, 4 kW of the average beam power was extracted into the atmosphere from the acceleration gap. With the geometric transparency of the support grid of the extraction foil window equal to 56%, this made 65% of the beam power in the gap. Further increasing the beam power was limited by the power of the high-voltage power supply.