Preliminary Study of UncertaintyDriven Plasma Diffusion II
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Abstract
We have constructed a semiclassical collisional diffusion model. In this model, a field particle is treated as either a point charge or a spatially distributed charge. The test particle is treated as a distributed point charge with Gaussian distribution. It was shown that the collisional changes in velocity in our model is of the same order as the classical theory for a typical proton in a fusion plasma of T = 10 keV and n = 10<sup>20</sup> m<sup>−3</sup>. It was also shown that the spatial extent of the distribution, or the quantummechanical uncertainty in position, for the test particle obtained in our model grows in time, and becomes of the order of the average interparticle separation Δl ≡ n<sup>−1/3</sup> during a time interval τ<sub>r</sub> ∼ × 10<sup>7</sup> Δl/g<sub>th</sub>, where g<sub>th</sub> = √ 2T/m is the thermal speed, with m being the mass of the particle under consideration. The time interval is 34 order of magnitudes smaller than the collision time. This suggests that particle transport cannot be understood in the framework of classical mechanics, and that the quantummechanical distribution of individual particles in plasmas may cause the anomalous diffusion.
Journal

 Plasma and Fusion Research

Plasma and Fusion Research (5), S2025S2025, 2010
Japan Society of Plasma Science and Nuclear Fusion Research