Abstract
Quantum mechanical plasma diffusion is studied using a semi-classical model with two different characteristic lengths; one is the average interparticle separation, and the other is the magnetic length. The diffusion coefficients D derived in this study show a dependence on several plasma parameters, such as temperature T, mass m, density n, and magnetic field B, similar to that observed experimentally. The numerical values of the diffusion coefficient D in this study are as large as that for neoclassical diffusion. We have pointed out in this study that (i) for distant encounters in typical fusion plasmas of T = 10 keV and n = 1020 m−3, the average potential energy ⟨U⟩ ∼ 30 meV is as small as the uncertainty in energy ΔE ∼ 40 meV, and (ii) for a magnetic field B = 3 T, the spatial size of the wavefunction in the plane perpendicular to the magnetic field is as large as lB ∼ 1.4 × 10−8m, which is much larger than the typical electron wavelength λe ∼ 10−11m.
