NichtMaxwellVerteilungen

NichtMaxwellVe, short for Nicht-Maxwellian Velocity Distribution Function, is a term used in plasma physics and computational fluid dynamics to describe velocity distributions that deviate from the classical Maxwell–Boltzmann shape. While a Maxwellian distribution assumes thermal equilibrium and predicts a specific exponential decay of particle speeds, many real‑world plasmas exhibit non‑thermal tails, anisotropy, or other irregularities due to external fields, wave‑particle interactions, or strong gradients. The NichtMaxwellVe formalism captures these features by allowing the probability density function to be expressed in terms of generalized mathematical forms, such as kappa, Lorentzian, or bi‑Maxwellian distributions.

The concept emerged in the late 1990s when satellite observations of the Earth's magnetosphere revealed persistent high‑energy tails that traditional models could not explain. Researchers then incorporated NichtMaxwellVe functions into kinetic simulations to better match observed particle fluxes and to account for anomalous transport phenomena. Modern plasma codes now routinely offer user‑selectable NichtMaxwellVe options, enabling more accurate predictions of heat conduction, wave damping, and instability thresholds in both laboratory and astrophysical settings.