Studies of single-particle motion in an FRC using the TriForce code*

Particle orbits in an field-reversed configuration (FRC) heated by odd-parity rotating magnetic fields (RMF_o) are highly stochastic, and thus present a useful case study for evaluating the accuracy and stability of simulation tools. In this work, we present a series of code-to-code comparisons for particles in an RMF_o-heated FRC between our particle-in-cell (PIC) code TriForce and the commercial PIC code LSP running in single-particle mode, as well as with the single-particle Hamiltonian code RMF. We show that, in single-particle mode, TriForce conserves energy sufficiently well to enable long-duration (multiple-second) runs, and also makes similar energization predictions to those made previously by the RMF code. We also examine the influence of a radial electric field, created by selective fusion product loss across the separatrix, on particle orbits in the core region. Planned studies with TriForce will examine the effect of collisions and collective effects in 3D FRC geometries.