Study of electron beam uniformity in large-area multi-aperture diode with arc plasma cathode

5th International Congress on Energy Fluxes and Radiation Effects 2016

Kandaurov, I.V.^1 ; Kurkuchekov, V.V.^1,2 ; Trunev, Yu A.^1,2

Budker Institute of Nuclear Physics of SB RAS, Novosibirsk

630090, Russia^1

Novosibirsk State University, Novosibirsk

630090, Russia^2

关键词: Arc discharge plasmas;    Cross sectional area;    Cross-sectional distribution;    Electron optical system;    Emission current density;    Large-area plasma;    Plasma generator;    X-ray diagnostics;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/830/1/012032/pdf
DOI  :  10.1088/1742-6596/830/1/012032

来源: IOP

【 摘 要 】

The use of plasma emission cathode in the conjunction with a multiple apertured electron optical system (EOS) is promising for the multi-MW class electron beams of a large cross-sectional area. In a multi-aperture source, the beam parameters could be raised simply due to increase of the number of apertures (i.e. an effective emission area), if a uniformity of the electron emission over a large-area plasma cathode is ensured. In the presented paper, the cross-sectional distribution of the emission current density was investigated using the X-ray diagnostic technique for two versions of the diode-type EOS, with electrodes performed as flat molybdenum "grids". The first one had 241 apertures arranged hexagonally inside a circle with a diameter of 8.3 cm and the second had 499 apertures within a circle of 11.8cm diameter. The emission plasma is produced using a single arc-discharge plasma generator placed on the axis at 20 cm from the EOS. It was demonstrated that multi-aperture systems with a single on-axis plasma generator can be effectively employed to obtain large-area beams, even in the presence of the guiding magnetic field. All apertures are emitting in the 499-apertured EOS. The beam current density is quite uniform up to the radius 2.5cm and gradually decreases to the periphery.