Schreiner, CedricSpanier, FelixVainio, Rami2018-04-172018-04-172018Schreiner, C. et al. 2018. Analytical treatment of particle motion in circularly polarized slab-mode wave fields. Journal of plasma physics, 84(1): Article no 905840104. [https://doi.org/10.1017/S0022377817001015]0022-37781469-7807 (Online)http://hdl.handle.net/10394/26766https://doi.org/10.1017/S0022377817001015https://www.cambridge.org/core/journals/journal-of-plasma-physics/article/analytical-treatment-of-particle-motion-in-circularly-polarized-slabmode-wave-fields/90F1007351EEF0C224564C13EF0B4B41Wave–particle interaction is a key process in particle diffusion in collisionless plasmas. We look into the interaction of single plasma waves with individual particles and discuss under which circumstances this is a chaotic process, leading to diffusion. We derive the equations of motion for a particle in the fields of a magnetostatic, circularly polarized, monochromatic wave and show that no chaotic particle motion can arise under such circumstances. A novel and exact analytic solution for the equations is presented. Additional plasma waves lead to a breakdown of the analytic solution and chaotic particle trajectories become possible. We demonstrate this effect by considering a linearly polarized, monochromatic wave, which can be seen as the superposition of two circularly polarized waves. Test particle simulations are provided to illustrate and expand our analytical considerationsenPlasma simulationPlasma wavesArticle