Field Precision Enhances Simulation Technology for 3D Relativistic Electron Guns

Designers face major challenges attempting to push intense microwave sources to higher frequencies. The size of conventional sources decreases proportionally with the radiation wavelength. The microwave output of miniature versions of standard devices is severely limited because of beam space-charge effects and power flux on material surfaces. A promising solution is to employ planar beams at high kinetic energy. Under these conditions, it is possible to transport substantially higher currents than circular electron beams at moderate energy. In addition, the planar shape allows a larger interaction volume for a given frequency, reducing problems of electrical breakdown and surface melting.

The design of guns and transport systems for non-circular, space-charge-dominated relativistic electrons beams in one of the grand challenges of computational applied physics. In addition to modeling high-energy electron dynamics, a planar-beam simulation must accomplish 3D calculations of electric and magnetic field that must include the self-consistent effects of beam charge and current. The OmniTrak code, the result of a five-year development program at Field Precision, meets these challenges. In a recent joint effort with the Department of Applied Science at the University of California Davis to characterize a 74 keV gun, run time proved to be the critical issue. The study involved a series of end-to-end simulations of a non-circular gun with injection into a complex planar periodic-permanent-magnet focusing system. Field Precision performed an intensive review of techniques for calculating three-dimensional, beam-generated magnetic fields. Incorporating the results in OmniTrak, the optimized code displayed an order-of-magnitude reduction in run time for relativistic guns. It proved possible to generate high-accuracy results in less than two hours on a conventional, high-performance PC.

OmniTrak is a self-contained tool that includes an interactive, graphical solid modeler, an automatic conformal mesh generators, solution programs for electric and magnetic field, the orbit tracking engine and post-processors. The mesh generator can accept complex parts directly from SolidWorks. OmniTrak handles low and high-current electron or ion beams over the energy range from fractions of an eV to several hundred MeV. In additional to high-power microwave sources, the code has application to vacuum microelectronics, photomultipliers, particle accelerators, electrostatic and magnetostatic spectrometers, electron microscopes and ion-mobility spectrometers. It is available in both 32 and 64-bit versions.

To get technical details and download the OmniTrak instruction manual, see:
http://www.fieldp.com/omnitrak.html