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Space charge plugin
Pierce gun
Thermionic gun
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Space charge plugin

Space charge plugin can be used to simulate the systems with a signi cant influence of mutual repulsive forces of particles. The plugin is capable to calculate only an average force, called the space charge e ffect. Random eff ects (Boersch and Loeffler eff ect) cannot be handled by this plugin.

The calculation of the system with the space charge is an iterative process, which strongly depends on the
mesh used for the evaluation of the electrostatic potential, on the number of particles used to represent the beam and also on the settings of the space charge calculation.

Emission plugin

Emission plugin can be used to calculate the space charge limited emission of electrons from the surface.

Publications

Numerical simulations of the thermionic electron gun for electron-beam welding and micromachining, Jansky, P; Zlamal, J; Lencova, B; Zobac, M; Vlcek, I; Radlicka, T, Vacuum 2009

 


 

Pierce gun

Pierce gun geometry

The first iteration of calculation (without space charge)

First iteration of calculation

The last iteration of calculation of space charge limited emission

The total current calculated by Child law is 9.274 uA. The current determined by Emission plugin is 9.619 uA.

 


 

Thermionic gun

Thermionic gun design

The region of the cathode is calculated in separate mesh

Cathode region

Equipotentials and trajectories at emissive area of cathode (determined by plugin)

Equipotentials and trajectories