scholarly journals Determination of electron energy, spectral width, and beam divergence at the exit window for clinical megavoltage x-ray beams

2009 ◽  
Vol 36 (3) ◽  
pp. 698-707 ◽  
Author(s):  
D. L. Sawkey ◽  
B. A. Faddegon
Keyword(s):  
Electron Energy ◽  
Spectral Width ◽  
Beam Divergence ◽  
X Ray ◽  
Exit Window

Determination of bonding in amorphous carbons by electron energy loss spectroscopy, Raman scattering and X-ray reflectivity

2000 ◽  
Vol 266-269 ◽  
pp. 765-768 ◽  
Author(s):  
A.C Ferrari ◽  
B Kleinsorge ◽  
G Adamopoulos ◽  
J Robertson ◽  
W.I Milne ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
X Ray ◽  
Electron Energy Loss

The Application of Bio-Standards for Electron Energy-Loss Analysis of Biological Materials

1990 ◽  
Vol 48 (2) ◽  
pp. 68-69
Author(s):  
Wim C. de Bruijn ◽  
Lianne W.J. Sorber
Keyword(s):  
Ion Exchange ◽  
Energy Loss ◽  
Electron Energy ◽  
Matrix Composition ◽  
Cell Organelles ◽  
X Ray ◽  
Loss Analysis ◽  
The Matrix ◽  
Electron Energy Loss

The application of standards, with a known externally determined element concentration, for the determination of unknown concentrations in cell organelles and tissue is a well known practice in X-ray microanalysis.The conditions to be met for a good standard have been formulated earlier. Pure element standards and standards made from PVP-films have been proposed for Electron Energy loss analysis. In this presentation we investigate the use for EELS-analysis of the ion-exchange bead Chelex100-type of standards, which can be co-embedded with tissue and have been applied successfully for X-ray microanalysis.The ion-exchange characteristics, the methods of loading and the matrix composition have been described before. Such bio-standards, which can be loaded with a variety of cations, are stored as a dry powder and can be co-embedded with the tissue to be analyzed. In that way the standard is present in each ultrathin section, at (an assumed) equal thickness as the cells or tissue, containing the unknown concentration of that element.

The Application of Electron Energy Loss Spectroscopy in Glass - Ceramic Microstructural Analysis

1977 ◽  
Vol 35 ◽  
pp. 250-251
Author(s):  
R. M. Anderson ◽  
A. Kumar
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Microstructural Analysis ◽  
Elemental Content ◽  
Light Elements ◽  
X Ray ◽  
Electron Energy Loss Spectrometry ◽  
C And N ◽  
Electron Energy Loss

The identification of unknown phases in crystallized glasses or ceramics has been difficult because the phases are generally composed of many elements; they crystallize into low-symmetry lattices; they contain numerous impurities, which may alter crystal structure or allow the observation of metastable phases; and they are not well represented in standard compilations of crystal data. Compounding the problem is the fact that energy- dispersive x-ray analysis (EDX) for elemental content can not be employed for elements with Z<11. This eliminates any possibility of qualitative analysis of the important Li, Be, and B glasses as well as determination of O, C and N content. Electron Energy Loss Spectrometry (ELS) has been shown to be a powerful method for the analysis of light elements. The ELS method is far more efficient at detecting light elements than x-ray detection, because the yield of energy loss electrons to inner shell excitation and ionizations is unity and because the electrons, which have lost energy encountering the sample, are scattered through very small angles, with the result that collection efficiencies are high.

Signal/Noise Ratio and Elemental Detectivity by Eels

1982 ◽  
Vol 40 ◽  
pp. 488-489
Author(s):  
R. F. Egerton
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Elemental Analysis ◽  
Electron Energy Loss Spectroscopy ◽  
Emission Spectroscopy ◽  
X Ray ◽  
Signal Noise ◽  
Characteristic Signal ◽  
Noise Ratio ◽  
Electron Energy Loss

An important parameter governing the sensitivity and accuracy of elemental analysis by electron energy-loss spectroscopy (EELS) or by X-ray emission spectroscopy is the signal/noise ratio of the characteristic signal.

Spatial resolution of X-ray microanalysis in thin foils

1978 ◽  
Vol 36 (1) ◽  
pp. 544-545
Author(s):  
R. Hutchings ◽  
I.P. Jones ◽  
M.H. Loretto ◽  
R.E. Smallman
Keyword(s):  
Spatial Resolution ◽  
Electron Probe ◽  
Beam Divergence ◽  
Inelastic Interaction ◽  
Specimen Thickness ◽  
High Current ◽  
Beam Spreading ◽  
X Ray ◽  
Thin Foils ◽  
Complex Calculation

There is increasing interest in X-ray microanalysis of thin specimens and the present paper attempts to define some of the factors which govern the spatial resolution of this type of microanalysis. One of these factors is the spreading of the electron probe as it is transmitted through the specimen. There will always be some beam-spreading with small electron probes, because of the inevitable beam divergence associated with small, high current probes; a lower limit to the spatial resolution is thus 2αst where 2αs is the beam divergence and t the specimen thickness.In addition there will of course be beam spreading caused by elastic and inelastic interaction between the electron beam and the specimen. The angle through which electrons are scattered by the various scattering processes can vary from zero to 180° and it is clearly a very complex calculation to determine the effective size of the beam as it propagates through the specimen.

Lateral resolution of the electron microbeam analysis

1978 ◽  
Vol 36 (1) ◽  
pp. 542-543
Author(s):  
H.J. Dudek
Keyword(s):  
Quantitative Analysis ◽  
Depth Resolution ◽  
Lateral Resolution ◽  
Cylindrical Particle ◽  
Correction Procedure ◽  
X Ray ◽  
Element Concentrations ◽  
Microbeam Analysis ◽  
The Matrix

The chemical inhomogenities in modern materials such as fibers, phases and inclusions, often have diameters in the region of one micrometer. Using electron microbeam analysis for the determination of the element concentrations one has to know the smallest possible diameter of such regions for a given accuracy of the quantitative analysis.In th is paper the correction procedure for the quantitative electron microbeam analysis is extended to a spacial problem to determine the smallest possible measurements of a cylindrical particle P of high D (depth resolution) and diameter L (lateral resolution) embeded in a matrix M and which has to be analysed quantitative with the accuracy q. The mathematical accounts lead to the following form of the characteristic x-ray intens ity of the element i of a particle P embeded in the matrix M in relation to the intensity of a standard S

Sign in / Sign up

Export Citation Format

Share Document