partikelström

partikelström is a term used in physics to describe the movement of discrete particles, such as electrons, ions, or atoms, through a medium. It is analogous to electric current, which represents the flow of charge, but a particle current focuses on the number of particles passing a given surface per unit time rather than the charge they carry. The particle flux J is often expressed in units of particles per square meter per second (m⁻²s⁻¹) and can be related to the current density j through j = q J, where q is the charge of each particle.

Particle currents arise in many contexts. In accelerator physics, beams of charged particles are steered and accelerated to high energies, producing intense particle currents that can be used for probing matter or for medical therapies. In plasma physics, ion and electron currents determine the behavior of the plasma, influence magnetic confinement in fusion devices, and drive phenomena such as auroras. Astrophysical jets and solar wind consist of particle streams that carry momentum and energy away from celestial bodies. In semiconductor devices, drift and diffusion of charge carriers constitute particle currents that underlie transistor operation.

The conservation of particle number is expressed by a continuity equation ∂n/∂t + ∇·J = S, where n is the particle density and S denotes sources or sinks. In steady‐state situations, the divergence of J vanishes. Accurate measurement of particle currents requires diagnostics such as Faraday cups, Langmuir probes, or imaging detectors. The concept of partikelström is essential for understanding transport phenomena in both laboratory and natural plasmas, guiding the design of fusion reactors, particle accelerators, and space exploration instruments.