Reflectivity and resolution X-ray dispersive and reflective structures for carbon, beryllium and boron analysis
AssigneeOvonic Synthetic Materials Company, Inc.
InventorsJames L. Wood, Keith L. Hart
Life of this patent
Estimating the term…
Abstract
X-ray dispersive and reflective structures and materials are constructed which exhibit improved characteristics in specific ranges of interest. The structures are formed of metallic and non-metallic layer pairs. The structures are formed of alternating layers of Cr:C, Ni:C or V:C for carbon analysis and Mo:B.sub.4 C for beryllium an boron analysis. The layered structures can be formed from Ni:C for analysis of both carbon and boron.
Claims2
In a method for the wavelength dispersive spectroscopic analysis for a light metal chosen from the group consisting of beryllium and boron, comprising the steps of:
- providing a sample;
- direction a beam of X-rays at said sample, to cause the sample to emit fluorescent radiation X-rays;
- directing said emitted X-rays onto an X-ray dispersive structure and reflecting said X-rays from said X-ray dispersive structure to a detector;
- and detecting said reflected X-rays to perform the analysis;
- the improvement wherein said X-ray dispersive structure includes a plurality of layer pairs formed on one another, one layer of said layer pair being formed of B.sub.4 C, the other layer of said layer pair being formed of vacuum deposited molybdenum, and said layer pairs having a d spacing of 35 to 200 Angstrom, whereby said layer pairs have X-ray dispersive properties over a predetermined first wavelength range of interest, and a maximum net peak to background ratio at a narrow second wavelength range of 55 to 130 Angstroms within said predetermined wavelength range of interest for the detection of beryllium and boron.
In a method for the spectroscopic analysis for carbon comprising the steps of:
- providing a sample;
- directing a beam of X-rays at said sample, to cause the sample to emit fluorescent radiation X-rays;
- directing said emitted X-rays onto an X-ray dispersive structure and reflecting said X-rays from the X-ray dispersive structure to a detector;
- the improvement wherein said X-ray dispersive structure comprises a plurality of layer pairs formed on one another, one layer of said layer pair being formed of carbon, and the other layer of said layer pairs being formed of a vacuum deposited transition metal chosen from the group consisting of nickel and vanadium, said layer pairs having a d spacing of 35 to 80 Angstroms, said layer pairs having X-ray dispersive properties over a predetermined first wavelength range of interest and a maximum net peak to background ratio at a narrow second wavelength range of 40 to 50 Angstroms within said predetermined wavelength range of interest for the detection of carbon.
Dependencies are inferred from the claim text.