The apparatus is based or energy dispersive X-ray Fluorescence. The sample is irradiated by a collimated beam of low energy X-rays and secondary radiation is detected composed by X-rays of elements present ir the irradiated object.
The apparatus is therefore composed by:
a) a low energy X-ray tube: a Hamamatsu X-ray tube was employed, working at 10 kV and 0.3 mA, with a Ca-anode) This tube, of very small dimensions, emits Ca-X rays (3.6 keV);
b) a low energy X-ray detector: an AMPTEK detector was employed, thermoelectrically cooled, of very small size and weight, with an energy resolution of about 250 eV at the S and Cl X-ray lines; a pocket multichannel analyser, for the collection of the X-ray spectra.
The calibration of the apparatus was carried out with standard samples of CaCO2 and Ca S04 The correlation counts-concentration was linear, and the minimum detection limit of about 0.5% .
The apparatus was successively employed to analyse the concentration and distribution of S on the fresco attributed to Pomarancio, at the basilica of S. Stefano Rotondo in Rome and of the internal of the basilica of S. Croce in Lecce
Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00
Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:
Publication Contact:
7th ECNDT, Park Alle 345, DK-2605 Broendby, Denmark, Fax: +45 46 26 70 11, Email: 101373.3414@compuserve.com
| NDTnet |