Annular electron beam generation using a ferroelectric cathode

Author

Golkowski, Czeslaw ; Flechtner, Donald ; Ivers, Jim D. ; Nation, John A. ; Schächter, Levi

Author_Institution

Sch. of Electr. Eng., Cornell Univ., Ithaca, NY, USA

Volume

26

Issue

3

fYear

1998

fDate

6/1/1998 12:00:00 AM

Firstpage

835

Lastpage

839

Abstract

In this paper, we report on the emission of electrons from a ferroelectric cathode in a coaxial gun geometry. The electrons are emitted from the inner conductor of the coaxial system and are accelerated radially. An axial magnetic field causes the formation of an azimuthal annular electron flow. The electrostatic potential distribution then leads to the ejection of the annular beam from the anode-cathode region into the drift space. A beam energy of up to 50 keV and an electron current of up to 250 A is typical in this proof of principle experiment. The Hull cutoff condition is found to considerably underestimate the magnetic field required to insulate the radial electron current flow in the diode. The results obtained are consistent with earlier data showing that the behavior of the ferroelectric is closely coupled to the changing state of the ferroelectric

Keywords

cathodes; electron beams; electron emission; electron guns; ferroelectric devices; magnetrons; microwave tubes; 250 A; 50 keV; Hull cutoff condition; annular electron beam generation; axial magnetic field; azimuthal annular electron flow; beam energy; coaxial gun geometry; diode; electron current; electron emission; electrostatic potential distribution; ferroelectric cathode; inner conductor; magnetic field; radial electron current flow; Acceleration; Cathodes; Coaxial components; Conductors; Electron beams; Electron emission; Electrostatics; Ferroelectric materials; Geometry; Magnetic fields;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/27.700846

Filename

700846