Transport characteristics of deuterium and hydrogen plasmas with ion internal transport barrier in the Large Helical Device

A remarkable extension of the high-ion-temperature (high-Ti) regime was obtained in deuterium plasma experiments in the Large Helical Device. In order to clarify transport characteristics in the ion internal transport barrier (ITB) formation with an isotope effect, a dataset of pure deuterium (nD/ne  >  0.8) and pure hydrogen (nH/ne  >  0.8) plasmas in the high-Ti regime were analyzed, and two mechanisms of transport improvement were characterized. A significant reduction of ion heat transport in the core of both deuterium and hydrogen plasmas was observed, indicating ion ITB formation. The dependence of the ion heat diffusivity on temperature ratio (Te/Ti) and normalized Ti-gradient (R/LTi  =  −(R/Ti)(dTi/dr)) was investigated in the core region, in which gyrokinetic simulations with the GKV code predict the destabilization of ion temperature gradient (ITG) modes. The Te/Ti dependence shows ITG-like property, while a significant deviation from the ITG-like property is found in the R/ dependence, indicating suppression of the ITG mode in the large R/ regime and resultant ion ITB formation. In the comparison between deuterium plasma and hydrogen plasma, the lower transport in the deuterium plasma is observed in both ion and electron heat diffusivities, indicating a significant isotope effect. It was found with the nonlinear turbulent transport simulation with GKV that the zonal flow enhancement contributes to the ITG suppression in the deuterium plasma

Isotope effects on transport in LHD

Isotope effects are one of the most important issues for predicting future reactor operations. Large helical device (LHD) is the presently working largest stellarator/helical device using super conducting helical coils. In LHD, deuterium experiments started in 2017. Extensive studies regarding isotope effects on transport have been carried out. In this paper, the results of isotope effect studies in LHD are reported. The systematic studies were performed adjusting operational parameters and nondimensional parameters. In L mode like normal confinement plasma, where internal and edge transport barriers are not formed, the scaling of global energy confinement time (τE) with operational parameters shows positive mass dependence (M0.27; where M is effective ion mass) in electron cyclotron heating plasma and no mass dependence (M0.0) in neutral beam injection heating plasma. The non-negative ion mass dependence is anti-gyro-Bohm scaling. The role of the turbulence in isotope effects was also found by turbulence measurements and gyrokinetic simulation. Better accessibility to electron and ion internal transport barrier (ITB) plasma is found in deuterium (D) plasma than in hydrogen (H). Gyro kinetic non-linear simulation shows reduced ion heat flux due to the larger generation of zonal flow in deuterium plasma. Peaked carbon density profile plays a prominent role in reducing ion energy transport in ITB plasma. This is evident only in plasma with deuterium ions. New findings on the mixing and non-mixing states of D and H particle transports are reported. In the mixing state, ion particle diffusivities are higher than electron particle diffusivities and D and H ion density profiles are almost identical. In the non-mixing state, ion particle diffusivity is much lower than electron diffusivity. Deuterium and hydrogen ion profiles are clearly different. Different turbulence structures were found in the mixing and non-mixing states suggesting different turbulence modes play a role

Luz Y Oscuridad en El Teatro De Calderon. (Spanish Text);

319 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988.En las comedias de capa y espada del capitulo primero, la funcion de las imagenes de luz y oscuridad como el dia y la noche es de causar mayor engano y confusion. Aun dentro de las comedias de un mismo genero, la funcion artistica de los efectos escenicos y dramaticos o hasta el proposito de Calderon varia mezclando los recursos tradicionales con los nuevos. Por esta razon se compara La dama duende, El galan fantasma y El encanto sin encanto que tratan del asunto misterioso, y a continuacion se trata del diseno del espacio dramatico en Casa con dos puertas, mala es de guardar.El proposito del capitulo segundo es examinar cual es la causa esencial de la tragedia en los dramas del honor en los que los protagonistas no dejan de buscar su propia satisfaccion sobre el que diran. La insistencia en el honor es precisamente la imagen del egoismo que solo atrae el enajenamiento y que no produce paz espiritual, idea distinta del altruismo del que se vale en las comedias de enredo. En este sentido El mayor monstruo los celos no es una excepcion; antes que un drama de celos o de amor desatinado, es un drama de honor.En el capitulo tercero el paganismo representa la imagen de la oscuridad y la fe cristiana, la luz, en los dramas con el tema de la conversion de los heroes paganos al cristianismo como en El magico prodigioso, etc.. Aqui la conversion se hace generalmente con la ayuda de Dios mediante algunos milagros, metodo formalista con una maxima efectividad visible y comprensible, y alude al sentido propagandistico de la Iglesia. En La devocion de la cruz se revela otra formula simbolica de luz y oscuridad. Aqui el autor se centra con mas rigor en exponer el concepto antitetico de la redencion y el pecado eterno que el proceso espiritual.En el ultimo capitulo se senala que el alcance de la luz como la salvacion del alma se realiza en el mundo terrenal sin milagros ni ayuda explicita de lo divino, sino por medio de la amarga experiencia de Segismundo.Tanto en este drama filosofico como en los dramas religiosos se asoma evidentemente la ensenanza biblica de manera sencilla.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD