Ubiquitous in the field of electric propulsion, thermionic hollow cathodes are electron sources ... For example, erosion of the cathode keeper face in long-duration wear tests causes premature device ...

Ubiquitous in the field of electric propulsion, thermionic hollow cathodes are electron sources ... For example, erosion of the cathode keeper face in long-duration wear tests causes premature device ...

This lovely little number is the EF80 pentode thermionic valve ... begins with slow and careful hand assembly of an EF80. The cathode is inserted into a mica disc, and a series of three grids ...

The idea is to make a heated filament the cathode, so electrons are ejected from the hot surface by thermionic emission. These are forced into a spiral path using a perpendicular magnetic field.

FEI Tecnai 12 The FEI Tecnai T12 located in the Wolfson Bioimaging Facility and is equipped with a 120 kV tungsten thermionic cathode and Ceta 16 M CCD detector. It is operated at ambient temperatures ...