Boundary conditions for displacement experiments through short laboratory soil columns [Dispersion coefficients]

The solid phase crystallization of chemical vapor deposited amorphous silicon films onto oxidized silicon wafers, induced either by thermal annealing or by ion beam irradiation at high substrate temperatures, has been extensively developed and it is reviewed here. We report and discuss a large variety of processing conditions. The structural and thermodynamical properties of the starting phase are emphasized. The morphological evolution of the amorphous towards the polycrystalline phase is investigated by transmission electron microscopy and it is interpreted in terms of a physical model containing few free parameters related to the thermodynamical properties of amorphous silicon and to the kinetical mechanisms of crystal grain growth. A direct extension of this model explains also the data concerning the ion-assisted crystal grain nucleation.

Crystal grain nucleation in amorphous silicon

A review of experiments and theory of electron cyclotron resonance heating (ECRH) and current drive (ECCD) is presented. An outline of the basic linear theory of wave propagation and absorption in the electron cyclotron range of frequencies and their harmonics is given and compared with experimental results from many devices. The experimental data base on quasilinear and nonlinear physics as well as on parametric wave decay is reviewed and compared to theory. Experiments and theory on doppler shifted absorption either by bulk or tail electrons (which can be created by other means) are discussed. ECRH provides means for controlled plasma breakdown and current ramp up in tokamaks and plays a key role in net current-free stellarator research. Start-up was investigated in many tokamaks and stellarators and the results are discussed in the light of the present day theoretical understanding. The role of ECRH to improve the understanding of both particle and energy confinement is described and special heating correlated features, such as 'density pump out' during ECRH are discussed. The application of modulated ECRH for perturbative heat wave studies and the comparison with both sawtooth heat pulse propagation and the steady state power balance analysis is presented. Electron cyclotron current drive is a possible method for current profile and MHD control in tokamaks and provides means for bootstrap current compensation in stellarators. The basic theory of electron cyclotron current drive is presented and compared to experiments in both tokamaks and stellarators. Experiments on sawtooth stabilization and MHD control by ECRH or ECCD are discussed and compared to theory. An increasing number of fusion devices is equipped with ECRH for bulk heating and sophisticated plasma physics investigations. A remarkable extension of the accessible plasma parameter range became possible by the recent development of sources with high power (1 MW) and frequency (110-160 GHz). Particular emphasis is given to new experiments and the refinement of theory incorporating plasma phenomena and the mutual impact on the wave physics.

http://iopscience.iop.org/article/10.1088/0741-3335/36/12/001/pdf

Electron cyclotron resonance heating and current drive in toroidal fusion plasmas

http://library.um.ac.id/free-contents/downloadpdf.php/buku/methods-of-modern-mathematical-physics-vol-i-functional-analysis-reed-michael-barry-simon-12066.pdf

Methods of modern mathematical physics (vol.) I : functional analysis / Reed Michael, Barry Simon)

Nonlinear behaviour of electrically actuated MEMS resonators

Dynamical characteristics of an electrically actuated microbeam under the effects of squeeze-film and thermoelastic damping

The generalized Hess method (GHM) gives a line shape expression which is formally equivalent to the Rautian–Sobel’man hard collision model of Dicke narrowing, but differs radically in the definition of one of the relaxation terms. The relaxation term leading to pressure broadening is the same, but the term leading to Dicke narrowing and ultimately to Doppler line shapes at zero density differs in certain important respects: (1) in GHM it is a weighted sum of the pressure broadening coefficient and an optical diffusion coefficient and (2) there is no sharp distinction between ‘‘velocity changing’’ and ‘‘phase changing’’ collisions. The Dicke narrowing term should thus be understood as including both collision types irretrievably intermixed, with GHM providing a prescription for both relaxation terms. Applied to HF v=0→1, j→j±1 absorption spectra in a bath of Ar and using an accurate interaction potential obtained from spectra of the van der Waals complex and essentially exact close coupling scattering S ma...

Effects of velocity changing collisions on line shapes of HF in Ar

In this work, the long‐time behavior of the solutions of the Vlasov–Poisson system when starting near a spatially homogeneous equilibrium is analyzed numerically. It is found that the asymptotic state toward which the system evolves is not a Bernstein–Green–Kruskal (BGK) equilibrium, but can rather be described by a superposition of BGK modes. Also, it is shown that the small oscillations at the plasma frequency after saturation in the one‐sided bump‐on‐tail instability are due to beating between the unstable mode and the least stable mode.

Numerical simulations of perturbed Vlasov equilibria

The frequency response curves of a non-uniform beam undergoing nonlinear oscillations are deter- mined analytically by the multiple time scale method, which provides approximate, but accurate results. The axial inertia in neglected, and so the equations of motion are statically condensed on the transversal displace- ment only. The nonlinearity due to the stretching of the axis of the beam is considered. The effects of variable cross-section, of variable material properties and of the distributed axial loading are taken into account in the formulation. They have been illustrated by means of two examples and are also compared with existing results. The main result of this work is that the effects of any type of non-uniformity can be detected by simple formulas.

Nonlinear vibrations of non-uniform beams by the MTS asymptotic expansion method

Solutions of the full nonlinear Vlasov–Poisson system for a one-dimensional unmagnetized plasma that correspond to undamped travelling waves near Maxwellian equilibria are analysed numerically using the splitting scheme algorithm. The numerical results are clearly in favour of the existence of such waves and confirm that there is a critical phase velocity below which they cannot be constructed.

Lucio Demeio

Papers

Dynamical characteristics of an electrically actuated microbeam under the effects of squeeze-film and thermoelastic damping

Effects of velocity changing collisions on line shapes of HF in Ar

Numerical simulations of perturbed Vlasov equilibria

Nonlinear vibrations of non-uniform beams by the MTS asymptotic expansion method

Numerical simulations of BGK modes