PRECISION MEASUREMENTS OF INTERATOMIC DISTANCES IN A SILICON CRYSTALLINE LATTICE BY AN OPTICAL METHOD USING A SCANNING INTERFEROMETER

An optical method is described for the precision determination of the relative angle between the diffraction planes of two crystals of a double flat crystal spectrometer. An angular precision, probable error ± 0.02 second of arc, is achieved. Measurement of relative angles are made by reference to a standard ruled scale. Absolute angles are determined by combining these measurements with measurements of the optical geometry. The factors which influence the precision measurements are discussed in detail. It is concluded that γ-ray energies between 0.5 and 2 Mev can be compared with a precision of a few parts in 105.

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Novel optical method for high precision measurements of dental structures

Materials Technology ◽

10.1179/1753555713y.0000000086 ◽

2013 ◽

Vol 29 (1) ◽

pp. 25-28 ◽

Cited By ~ 1

Author(s):

B. Trentadue

Keyword(s):

High Precision ◽

Optical Method ◽

Precision Measurements

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Atomic orientation effects in proton stopping at low velocity

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100077116 ◽

1983 ◽

Vol 41 ◽

pp. 708-709

Author(s):

Kin Lam

Keyword(s):

Polycrystalline Material ◽

Charged Particles ◽

Target Material ◽

Stopping Power ◽

Low Velocity ◽

Electronic Density ◽

Interatomic Distances ◽

Frame Work ◽

Image Position ◽

Atomic Orientation

The energy of moving ions in solid is dependent on the electronic density as well as the atomic structural properties of the target material. These factors contribute to the observable effects in polycrystalline material using the scanning ion microscope. Here we outline a method to investigate the dependence of low velocity proton stopping on interatomic distances and orientations.The interaction of charged particles with atoms in the frame work of the Fermi gas model was proposed by Lindhard. For a system of atoms, the electronic Lindhard stopping power can be generalized to the formwhere the stopping power function is defined as

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Simulation of three Dimensional Defect Images in Transmission Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100092311 ◽

1976 ◽

Vol 34 ◽

pp. 470-471

Author(s):

W. D. Cooper ◽

C. S. Hartley ◽

J. J. Hren

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Three Dimensional ◽

Crystalline Lattice ◽

Continuum Models ◽

Thin Foils ◽

Transmission Electron ◽

Microscope Images ◽

General Computer Program ◽

General Computer

Interpretation of electron microscope images of crystalline lattice defects can be greatly aided by computer simulation of theoretical contrast from continuum models of such defects in thin foils. Several computer programs exist at the present time, but none are sufficiently general to permit their use as an aid in the identification of the range of defect types encountered in electron microscopy. This paper presents progress in the development of a more general computer program for this purpose which eliminates a number of restrictions contained in other programs. In particular, the program permits a variety of foil geometries and defect types to be simulated.The conventional approximation of non-interacting columns is employed for evaluation of the two-beam dynamical scattering equations by a piecewise solution of the Howie-Whelan equations.

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Some Aspects of Exelfs Analysis in the Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600000477 ◽

1980 ◽

Vol 38 ◽

pp. 118-119

Author(s):

D. E. Johnson ◽

S. Csillag

Keyword(s):

Fine Structure ◽

Electron Microscope ◽

Energy Loss ◽

Analytical Electron Microscopy ◽

Interference Effects ◽

Interatomic Distances ◽

X Ray ◽

Structure Information ◽

Microanalytical Technique ◽

Analytical Electron

Recently, the applications area of analytical electron microscopy has been extended to include the study of Extended Energy Loss Fine Structure (EXELFS). Modulations past an ionization edge in the energy loss spectrum (EXELFS), contain atomic fine structure information similar to Extended X-ray Absorbtion Fine Structure (EXAFS). At low momentum transfer the main contribution to these modulations comes from interference effects between the outgoing excited inner shell electron waves and electron waves backscattered from the surrounding atoms. The ability to obtain atomic fine structure information (such as interatomic distances) combined with the spatial resolution of an electron microscope is unique and makes EXELFS an important microanalytical technique.

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