2013/07/28 by R. A. Treumann, W. Baumjohann, Treumann, R. A. +1
Engineering · Physics and Astronomy · #Atomic and Molecular Physics #FOS: Physical sciences #Particle accelerators and beam dynamics #Plasma Physics (physics.plasm-ph) #Quantum and Classical Electrodynamics #Space Physics (physics.space-ph)
paper · pdf · doi:10.48550/arxiv.1307.7346
openalex publication_date 2013/07/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The average (thermal) gyroradius of charged particles is re-examined from a quantum-mechanical point of view. The straight quantum-mechanical calculation clearly reproduces its conventionally used random-mean-square (rms) expectation value. The quasi-classical approach reproduces its mean expectation value as well thus confirming the purely classical calculation. It shows that the fluctuations in the gyroradius amount to 21.5% of its rms value. This fluctuation is, however, within the usual √(2)-"freedom" range of choice in the definition of the rms gyroradius respectively the mean thermal speed on which the rms value is based, its correct (nonrelativistic) value vt2= 2T_⊥/me and its simplified version vt2=T_⊥/me.