Motivation and Goals

Ef general design goals are following:

1. Focus on simulation of low-energy charged particle beam devices: ion sources, electron guns, etc. Current goal is simulation of electron beam ion source (EBIS).
2. Detailed control over simulation algorithm. This is essential if nonstandard numerical scheme is required.
3. Support for parallel execution (both CPU and GPU) to handle large number of particles and long simulation times.
4. Integration with CAD systems to simplify device geometry specification and data analysis.
5. Source code is free and open, available for modifications and redistribution.

They have been influenced by the following considerations:

Ef is developed with a particular application in mind: simulation and optimization of certain type of ion source - electron beam ion source, EBIS. Such sources are commonly used to produce beams of highly charged ions for applications in particle physics, medicine and surface modification. Their principle of operation employs an electrostatic ion trap to hold the ions while ionizing them to desired charge state with an electron beam.

This problem is non-relativistic (unlike many other accelerator physics problems). Due to large number of particles and long time duration to simulate it is computationally demanding and requires parallelization to accomplish the simulation in reasonable amount of time. Different spatial and time scales are involved: slow ions and fast electrons have uncomparable time evolution scales, and transversal size of the beam (less than 1 mm radius) is much much less longitudinal trap length (50-100 cm). This requires fine control over details of simulation algorithm to incorporate certain modifications in the numerical scheme if necessary.

Device geometry plays a major role in low-energy beam devices. Therefore, integration with CAD systems is highly desirable to simplify geometry specification. A useful feature would be to provide an opportunity to automate the search for the optimal geometry of the device and it’s parameters. For practical means, the following parameters are important: ... An ideal program should allow to display them and provide tool to analyze them easily.

The principle of reproducible research and general common sense dictate ...