Development of Three-Dimensional Neoclassical Transport Simulation Code with High Performace Fortran on a Vector-Parallel Computer

A neoclassical transport simulation code (FORTEC-3D) applicable to threedimensional configurations has been developed using High Performance Fortran (HPF). Adoption of computing techniques for parallelization and a hybrid simulation model to the delta f Monte-Carlo method transport simulation, including non-local transport effects in three-dimensional configurations, makes it possible to simulate the dynamism of global, non-local transport phenomena with a self-consistent radial electric field within a reasonable computation time. In this paper, development of the transport code using HPF is reported. Optimization techniques in order to achieve both high vectorization and parallelization efficiency, adoption of a parallel random number generator, and also benchmark results, are shown

Ultra-low-frequency self-oscillation of photocurrent in InxGa1–xAs/Al0.15Ga0.85As multiple-quantum-well p–i–n diodes

We report an observation of ultra-low-frequency self-oscillation of photocurrent in InxGa1–xAs/Al0.15Ga0.85As multiple-quantum-well p–i–n diodes. The photocurrent intensity shows self-oscillations with a characteristic frequency of ~0.1 Hz at low temperatures under reverse bias voltages. The photocurrent self-oscillation depends on applied bias voltage, temperature, illumination power, and indium content of quantum-well layers. These dependences indicate that the photocurrent self-oscillation is attributed to photogenerated carriers trapped in localized centers within InxGa1–xAs quantum-well regions

A holomorphic representation of the Jacobi algebra

A representation of the Jacobi algebra $\mathfrak{h}_1\rtimes \mathfrak{su}(1,1)$ by first order differential operators with polynomial coefficients on the manifold $\mathbb{C}\times \mathcal{D}_1$ is presented. The Hilbert space of holomorphic functions on which the holomorphic first order differential operators with polynomials coefficients act is constructed.Comment: 34 pages, corrected typos in accord with the printed version and the Errata in Rev. Math. Phys. Vol. 24, No. 10 (2012) 1292001 (2 pages) DOI: 10.1142/S0129055X12920018, references update

Invariant Differential Operators for Non-Compact Lie Groups: the Sp(n,R) Case

In the present paper we continue the project of systematic construction of invariant differential operators on the example of the non-compact algebras sp(n,R), in detail for n=6. Our choice of these algebras is motivated by the fact that they belong to a narrow class of algebras, which we call 'conformal Lie algebras', which have very similar properties to the conformal algebras of Minkowski space-time. We give the main multiplets and the main reduced multiplets of indecomposable elementary representations for n=6, including the necessary data for all relevant invariant differential operators. In fact, this gives by reduction also the cases for n<6, since the main multiplet for fixed n coincides with one reduced case for n+1.Comment: Latex2e, 27 pages, 8 figures. arXiv admin note: substantial text overlap with arXiv:0812.2690, arXiv:0812.265

Non-local Simulation of the Formation of Neoclassical Ambipolar Electric Field in Non-axisymmetric Configurations

Neoclassical transport simulation code (FORTEC-3D) applicable to non-axisymmetric configurations is developed. Adoption of a new hybrid simulation model, in which ion transport is solved by using the delta f Monte-Carlo method including the finite-orbit-width effects while electron transport is solved by a reduced ripple-averaged kinetic equation, makes it possible to simulate the dynamism of non-local transport phenomena with self-consistently developing radial electric field within a allowable computation time. Time evolution of radial electric field in LHD plasma is simulated in the full volume of confinement region, and the finite-orbit-width effect of neoclassical transport is found to make the negative ambipolar electric field more larger than the prediction by a local transport theory