SOURCE-TO-SAMPLE DISTANCE INDEPENDENT EFFICIENCY TECHNIQUE FOR X-RAY FLUORESCENCE ANALYSIS

A technique to make the detection efficiency, in XRF systems, less dependent on the source-to-sample distance is disclosed. It is shown that this dependence can be made more constant within a large range of distances if a properly calculated an nular mask is used. The calculations for this mask were...

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Bibliographische Detailangaben
Hauptverfasser:	FERREIRA DOS SANTOS, JOAQUIM MARQUES, NABAIS CONDE, CARLOS ALBERTO, MAIA PEREIRA, JORGE MANUEL
Format:	Patent
Sprache:	eng ; fre
Schlagworte:	GAMMA RAY OR X-RAY MICROSCOPES INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES IRRADIATION DEVICES MEASURING NUCLEAR ENGINEERING NUCLEAR PHYSICS PHYSICS TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOTOTHERWISE PROVIDED FOR TESTING
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Beschreibung
Zusammenfassung:	A technique to make the detection efficiency, in XRF systems, less dependent on the source-to-sample distance is disclosed. It is shown that this dependence can be made more constant within a large range of distances if a properly calculated an nular mask is used. The calculations for this mask were made using the Monte Carlo met hod to compute the response curve of a full transmission elemental annulus with vari able radius, and a linear programming Simplex method to optimize the uniformity of th e response for a combination of those elemental annuluses. Experimental results (f or Ca, Ti, V and Zr), in good agreement with the calculated ones, are presented and sho w that constant efficiency values within ~5% can be obtained when the sample dista nce varies from 3 to 12 mm. However, peak absolute efficiencies are then reduced by about a factor 5.