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arXiv · 1307.7346

QM theory of the thermal electron gyroradius

R. A. Treumann·W. Baumjohann
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Abstract

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 $\sqrt{2}$-"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 $v_t^2= 2T_\perp/m_e$ and its simplified version $v_t^2=T_\perp/m_e$.

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R. A. Treumann, W. Baumjohann. 2013-07-28. QM theory of the thermal electron gyroradius. https://arxiv.org/abs/1307.7346

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