Application of mass multielement prompt gamma activation analysis to determine the elemental composition of archaeological and other samples

Seminars

Frank Laboratory of Neutron Physics

Nuclear Physics Department

Leader – E. V. Lychagin

Date and Time: Wednesday, 14 April 2021, at 11:00 AM

Venue: online seminar on Webex, Frank Laboratory of Neutron Physics

Seminar topic: «Application of mass multielement prompt gamma activation analysis to determine the elemental composition of archaeological and other samples»

Authors: S. B. Borzakov, A. Zh. Zhomartova, A. Yu. Dmitriev

Speaker: A. Zh. Zhomartova

Abstract:

The method of prompt gamma activation analysis (PGAA) was used for the first time in Russia, at FLNP JINR to study archaeological ceramics.

PGAA is a completely non-destructive analytical method for qualitative and quantitative determination with different sensitivity of several tens of elements in samples of about 100 mg to several grams or more. The method is suitable for studying homogeneous large size samples, can be used for the analysis of samples with matrices of light elements that are poorly detected by other methods.

The pulsed reactor IBR-2 is used as a neutron source. The channel is equipped with a curved neutron guide. Gamma rays are recorded by a radiation-resistant HPGe Canberra detector with the 2.3 keV resolution for the 60Co gamma line with the energy of 1332.5 keV and 70% relative efficiency. The detector is calibrated in energy and efficiency in the energy range from 50 keV to 8 MeV. The thermal neutron flux density is approximately 6·105 n·cm-2·s-1.

The obtained spectra are processed using the Genie-2000 programme, for which a special library of prompt gamma lines has been done. Calculations of mass fractions are automated, for which a special software and a library of nuclear constants have been created.

Fragments of ceramic vessels of the 15th-16th centuries made of red clay, discovered during excavations in the Moscow Kremlin and in Bolgar, and archaeological gold-silver alloy (presumably electrum), and a rare astrophysical object, the Chelyabinsk meteorite, were investigated. The results were compared with the data of other methods – neutron activation and X-ray fluorescence analysis and showed good agreement – within 2-3 standard deviations. The data obtained were used by scientists from the Institute of Archeology of the Russian Academy of Sciences to solve topical problems in the field of archaeology.