SOLPS-ITER modeling of beryllium trace impurity in ITER

Beryllium transport modeling was carried out in the trace impurity regime by SOLPS-ITER code for tokamak ITER. It is valuable for developing of diagnostics protection from beryllium deposition. TRIM reflection model and Bogdanskii formula sputtering model were applied. The idea is to show possibility of using this code for beryllium transport. This code has key advantage comparing to other codes, which study beryllium transport, because in it the main plasma and impurities are described self-consistently. Therefore, if beryllium affect the background plasma, only this code can take this effect into account. Test calculations were performed with suppressed sputtering yield by 10 times, to reach trace impurity regime. Main features of behavior of beryllium in the tokamak were studied, however under restriction of static wall conditions. Sources, sinks, fluxes and density distribution were determined. In this test calculation plasma state kept unchanged as expected. Distribution of impinging and absorbed fluxes on the outer divertor plate were established in the position of divertor diagnostics. Main ways for the further improvement are suggested.

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Investigations of plasma-wall interaction by H alpha resonant scattering in the tokamak UNITOR

Journal of Plasma Physics ◽

10.1017/s002237780000026x ◽

1982 ◽

Vol 28 (2) ◽

pp. 281-291 ◽

Cited By ~ 8

Author(s):

G. Reinhold ◽

J. Hackmann ◽

J. Uhlenbusch

Keyword(s):

Density Distribution ◽

Resonant Scattering ◽

Background Plasma ◽

Hydrogen Atoms ◽

Plasma Parameters ◽

Special Regard ◽

Interaction Processes ◽

Wall Interaction

The Hα resonant scattering diagnostics applied to the tokamak UNITOR is described. The measurements yield the density distribution of excited hydrogen atoms as a result of plasma-wall interaction processes and background plasma parameters. Special regard has been given to the influence of recycling processes.

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Criteria and Methods for Reliable Three-Dimensional Image Reconstruction

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051669 ◽

1974 ◽

Vol 32 ◽

pp. 330-331

Author(s):

R. A. Crowther

Keyword(s):

Image Reconstruction ◽

Finite Number ◽

Density Distribution ◽

Electron Micrographs ◽

Mathematical Problem ◽

Three Dimensional ◽

Ideal Case ◽

Dimensional Image ◽

General Object ◽

The Ideal

The reconstruction of a three-dimensional image of a specimen from a set of electron micrographs reduces, under certain assumptions about the imaging process in the microscope, to the mathematical problem of reconstructing a density distribution from a set of its plane projections.In the absence of noise we can formulate a purely geometrical criterion, which, for a general object, fixes the resolution attainable from a given finite number of views in terms of the size of the object. For simplicity we take the ideal case of projections collected by a series of m equally spaced tilts about a single axis.

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A study on α-RuCl3 crystal structure by scanning tunneling microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100152124 ◽

1989 ◽

Vol 47 ◽

pp. 30-31

Author(s):

H.-J. Cantow ◽

H. Hillebrecht ◽

S. Magonov ◽

H. W. Rotter ◽

G. Thiele

Keyword(s):

Crystal Structure ◽

Density Distribution ◽

Scanning Tunneling Microscopy ◽

Electron Density ◽

Structure Determination ◽

Electron Density Distribution ◽

Scanning Tunneling ◽

Monoclinic Space Group ◽

Tunneling Microscopy ◽

X Ray

From X-ray analysis, the conclusions are drawn from averaged molecular informations. Thus, limitations are caused when analyzing systems whose symmetry is reduced due to interatomic interactions. In contrast, scanning tunneling microscopy (STM) directly images atomic scale surface electron density distribution, with a resolution up to fractions of Angstrom units. The crucial point is the correlation between the electron density distribution and the localization of individual atoms, which is reasonable in many cases. Thus, the use of STM images for crystal structure determination may be permitted. We tried to apply RuCl3 - a layered material with semiconductive properties - for such STM studies. From the X-ray analysis it has been assumed that α-form of this compound crystallizes in the monoclinic space group C2/m (AICI3 type). The chlorine atoms form an almost undistorted cubic closed package while Ru occupies 2/3 of the octahedral holes in every second layer building up a plane hexagon net (graphite net). Idealizing the arrangement of the chlorines a hexagonal symmetry would be expected. X-ray structure determination of isotypic compounds e.g. IrBr3 leads only to averaged positions of the metal atoms as there exist extended stacking faults of the metal layers.

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