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Analysis based on a gyro-kinetic ballooning stability code predicts that both the ion and electron thermal diffusivities, due to the ion temperature gradient (ITG) and electron temperature gradient (ETG) modes, respectively, increase with the safety factor q almost linearly. In the case of ITG driven ion thermal diffusivity, the q dependence originates from the coupling to the ion acoustic mode, and in the case of the electron thermal diffusivity due to the ETG mode, it emerges from the coupling to the skin size drift mode. In the ETG mode, charge neutrality does not hold for typical tokamak discharges, and mixing length estimates yield a thermal diffusivity large enough to be relevant to experiments.

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High-energy muons generated from cosmic-ray particle showers have been shown to exhibit properties ideal for imaging the interior of large structures. This paper explores the possibility of using a single portable muon detector in conjunction with image reconstruction methods used in nuclear medicine to reconstruct a 3D image of the interior of critical infrastructure such as the Zero Energy Deuterium (ZED-2) research reactor at Canadian Nuclear Laboratories' Chalk River site. The ZED-2 reactor core and muon detector arrangement are modeled in GEANT4 and Monte Carlo measurements of the resultant muon throughput and angular distribution at several angles of rotation around the reactor are generated. Statistical analysis is then performed on these measurements based on the well-defined flux and angular distribution of muons expected near the surface of the earth. The results of this analysis are shown to produce reconstructed images of the spatial distribution of nuclear fuel within the core for multiple fuel configurations. This one-sided tomography concept is a possible candidate for examining the internal structure of larger critical facilities, for example the Fukushima Daiichi power plant where the integrity of the containment infrastructure and the location of the reactor fuel is unknown.