| |
 |
UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:25 |
 |
|
|
|
Conference: Bucharest University Faculty of Physics 2012 Meeting
Section: Nuclear and Elementary Particles Physics
Title:
Retrospective dosimetry and isotopic pattern determination via gamma-ray spectrometry for archaeological samples from southern Romania
Authors:
Adina OLACEL, O. SIMA, E. S. TEODOR, R. SUVAILA
Affiliation:
University of Bucharest
E-mail
adinaolacel@gmail.com, ion.rares@gmail.com
Keywords:
Gamma-ray spectrometry, efficiency calibration, retrospective dosimetry, isotopic pattern
Abstract:
The analysis of soil samples from archaeological sites can lead to age determination of artifacts found within the sampling sites. Gamma spectrometric analysis leads to the annual dose of natural gamma radiation to be assessed to those artifacts. The actual dating process implies a more complex dosimetric approach and also luminescent measurements in order to establish the total dose, admitting that meanwhile objects were not subjected to brightness and/or excessive temperatures. Dividing the total dose by the annual one leads to the age of the objects. Gamma spectra analysis of those same samples also provides information on neutron activated gamma emissions. Neutron irradiation followed by acquisition of another set of spectra is a method meant to attempt isotopic pattern recognition, in order to build a reference materials database, first of its kind in Romania. For this analysis we used last generation Hyper Pure Germanium detectors, calibrated with standard sources of 133Ba, 137Cs and 152Eu in low background. The extension of efficiency calibration to higher energies was achieved using reference materials from IAEA intercomparison experiments containing nuclides with unknown activity, but having several peaks from which at least one is located in the calibrated region of the spectrum in terms of efficiency; among the nuclides considered for efficiency calibration extension at different energies from those available directly via calibration sources we note 214Bi, 208Tl, 228Ac and 214 Pb. The experimental methods, the gamma spectrometric chain, the related corrections for detector-sample geometry, attenuation and coincidence effects are described here, and the first experimental results are presented.
|
|
|
|