The new 3D electron gun and collector modeling tool: MICHELLE

A new 3D finite-element gun and collector modeling code, MICHELLE, is under development at SAIC in collaboration with industrial partners and national laboratories. This development program has been designed specifically to address the shortcomings of current beam optics simulation and modeling tools for vacuum electron devices. The program specifically targets problem classes including gridded-guns, sheet-beam guns, multi-beam devices, and anisotropic collectors. In particular, although there are 3D gun codes that exist today, their ability to address fine scale features is somewhat limited in 3D due to disparate length scales found in certain classes of devices. Additionally, features like advanced emission models, including thermionic Child´s law and comprehensive secondary emission models also need attention for detailed modeling, and are included in the code. As part of this new effort, an algorithmic representation of a comprehensive model of secondary emission is being developed for this computational tool in order to achieve an accurate beam collection design capability. The basic physics model in the code is based on the equilibrium steady state application of the electrostatic PIC approximation employing both hexahedral and tetrahedral grid systems.