Ion-Acoustic Waves and the Proton-Alpha Streaming Instability at Collisionless Shocks

• DOI: 10.48550/arxiv.2502.07953
• Publication Date: 2025-02-11
• Authors: D. B. Graham; Y. V. Khotyaintsev; Ahmad Lalti
• Keywords: Streaming instability; Alpha (finance)

Ion-acoustic waves are routinely observed at collisionless shocks and could be an important source of resistivity. The instability the effects not fully understood. We show, using Magnetospheric Multiscale (MMS) mission observations numerical modeling, that across low Mach number a large relative drift between protons alpha particles develops, which can unstable to proton-alpha streaming instability. results from linear analysis simulation show resulting agree with wave properties. generated ion-acoustic predicted become nonlinear form ion holes, maintained by trapped alphas. reduces alphas, heats ions, thus providing resistivity shocks.