Share Email Print
cover

Proceedings Paper

Thermoelectrically cooled semiconductor detectors for portable energy-dispersive x-ray fluorescence equipment
Author(s): Roberto Cesareo; Alfredo Castellano; Carlo Fiorini; Giovanni E. Gigante; Jan S. Iwanczyk; Antonio Longoni; John A. Pantazis; Juan Luis Pena Chapa; Marco A. Rosales
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Thermoelectrically cooled semiconductor detectors, such as Si- PIN, Si-strip and HgI2, coupled to miniaturized low-power x-ray tubes, are well suited for constructing portable systems for energy-dispersive x-ray fluorescence analysis (EDXRF) of samples of archaeological interest. The Si-PIN detector is characterized by a thickness of about 300 micrometer, an area of about 2 by 3 mm2, an energy resolution of about 250 - 300 eV at 5.9 keV and an entrance window of 75 micrometers. The Si-strip detector has approximate the same area and thickness, but an energy resolution of 145 eV at 5.9 keV. The efficiency of these detectors is around 100% from 4 to 10 keV, and then decreases versus energy, reaching 10% at 30 keV. Coupled to a miniaturized 10 kV, 0.1 mA, Ca-anode or to a miniaturized 30 kV, 0.1 mA, W-anode x-ray tubes, completely portable systems can be constructed, which are able to analyze K-lines of elements up to about silver, and L-lines of heavy elements. The HgI2 detector has an efficiency of about 100% in the whole range of x rays, and an energy resolution of about 200 eV at 5.9 keV. Coupled to a small 50 kV, 1 mA, W- anode x-ray tube, a portable system can be constructed, for analysis of practically all elements. These equipments were applied to analysis in the field of archaeometry and in all applications for which portable systems are needed or at least useful (for example x-ray transmission measurements, x-ray microtomography and so on). More specifically, concerning EDXRF analysis, ancient gold samples were analyzed in Rome, in Mexico City and in Milan, nuragic bronzes in Sassari, ceramics of various origin in Merida, La Habana and Sassari, and sulfur (due to pollution) in an old Roman fresco in S. Stefano Rotondo (Rome). Concerning transmission measurements, ancient copper coins and wood samples were analyzed, and microtomographic measurements are in progress to improve the quality of the image.

Paper Details

Date Published: 7 July 1997
PDF: 10 pages
Proc. SPIE 3115, Hard X-Ray and Gamma-Ray Detector Physics, Optics, and Applications, (7 July 1997); doi: 10.1117/12.277695
Show Author Affiliations
Roberto Cesareo, Univ. di Sassari (Italy)
Alfredo Castellano, Univ. di Lecce (Italy)
Carlo Fiorini, Politecnico di Milano (Italy)
Giovanni E. Gigante, Univ. di Roma "La Sapienza" (Italy)
Jan S. Iwanczyk, Xsirius Inc. (United States)
Antonio Longoni, Politecnico di Milano (Italy)
John A. Pantazis, Amptek Inc. (United States)
Juan Luis Pena Chapa, CINVESTAV (Mexico)
Marco A. Rosales, Univ. de las Americas (Mexico)


Published in SPIE Proceedings Vol. 3115:
Hard X-Ray and Gamma-Ray Detector Physics, Optics, and Applications
Richard B. Hoover; F. Patrick Doty, Editor(s)

© SPIE. Terms of Use
Back to Top