Benchmarking of B2 Code with a One-Dimensional Plasma Fluid Model Incorporating Anisotropic Ion Pressures on Simple Mirror Configurations

A plasma fluid code B2 has been benchmarked with a one-dimensional plasma fluid model incorporating the anisotropic ion pressures (AIP model) on simple mirror configurations. In a low collisionality case, profiles of plasma parameters of the B2 code deviate from those of the AIP model. The validity of the viscous-flux approximation is investigated by direct comparisons with the anisotropic part of the ion pressure indicating the invalidity of the viscous-flux approximation is considered to be responsible to deviations of profiles. In addition, supersonic plasma flows downstream from the mirror throat are observed

A case of epilepsy with myoclonic atonic seizures caused by SLC6A1 gene mutation due to balanced chromosomal translocation

Introduction Epilepsy with myoclonic atonic seizures (EMAtS) was previously thought to occur in normally developing children. We report a female case of EMAtS and mild developmental delay before onset. Importantly, a de novo balanced chromosomal translocation was recognized in the patient. Case presentation The patient was a 4-year-old girl. Mild developmental delay was observed during infancy. At the age of one and a half years, she developed atonic seizures once a month. At 4 years of age, her seizures increased to more than 10 times per hour. An ictal electroencephalogram (EEG) showed a 3–4-Hz spike-and-wave complex, which was consistent with atonic and myoclonic seizures of the trunk, eyelids, and lips. Therefore, EMAtS was diagnosed based on the symptoms and EEG findings. After administration of valproic acid (VPA), the epileptic seizures disappeared immediately. At the age of 5 years and 2 months, the seizures recurred but disappeared again when the dose of VPA was increased. Subsequently, no recurrence was observed until 6 years and 3 months of age on VPA and lamotrigine. Chromosome analysis of the patient disclosed 46,XX,t(3;11)(p25;q13.1)dn. Long-read sequencing of the the patient’s genomic DNA revealed that the 3p25.3 translocation breakpoint disrupted the intron 7 of the SLC6A1 gene. Conclusion The SLC6A1 disruption by chromosome translocation well explains the clinical features of this patient. Long-read sequencing is a powerful technique to determine genomic abnormality at the nucleotide level for disease-associated chromosomal abnormality

Self-consistent simulation of supersonic plasma flows in advanced divertors

Advanced divertors gain larger plasma wetted area by poloidal or total flux expansion. Qualitative characteristics of supersonic plasma flows which are generated by the magnetic nozzle effect are studied by using a plasma fluid model incorporating anisotropic ion pressure (AIP model). The AIP model can self-consistently simulate supersonic plasma flows because, unlike the widely-used plasma fluid model (the Braginskii equations), the equation of parallel plasma momentum in it is described as a hyperbolic-type and the plasma flow velocity is solved without using explicit boundary conditions at the sheath entrance in front of divertor plates. In comparisons of plasma profiles between the AIP model and the Braginskii equations, it is observed that the plasma flow velocity in the Braginskii equations is forced to the sound speed at the sheath entrance in conditions of decelerating supersonic plasma flows leading to qualitative deviations with the AIP model. In an application of the AIP model to a scrape-off layer/divertor region incorporating super-X divertors with various flux-expansion ratios, supersonic plasma flows in divertor regions and highly anisotropic ion temperatures are successfully simulated. It is also demonstrated that it becomes easier with the AIP model to explain the mechanisms of generations of supersonic plasma flows and acceleration/deceleration of them (including stationary shock waves) in flux-expanding divertors from the mirror effect point of view

Spatiotemporal Structure of Hα Emission from the Detached Plasma in GAMMA 10/PDX

High-speed camera measurement was performed for analyses of detached plasma fluctuation in the GAMMA 10/PDX tandem mirror device. Significant spectral peaks at frequencies of 1.5 and 3 kHz were observed to have several local maxima along the vertical, near the entrance of the V-shaped target. Wavelet analysis indicated that 1.5- and 3-kHz fluctuations became non-simultaneously strong. Their phase relationships demonstrated inversion-symmetric and symmetric features with respect to the midplane. Such spectral patterns were interpreted as the line-integral of odd- and even-mode structures. It is suspected that the vertical edge part was due to radially elongated structures with an azimuthal phase shift