Laser ablation coupled to mass quadrupole spectrometry for analysis in the cultural heritage

Plasma Physics by Laser and Applications 2013 Conference

Torrisi, A.^1 ; Cutroneo, M.^2 ; Castrizio, E.D.^3 ; Torrisi, L.^2

Dip.to di Fisica e Astronomia, Università di Catania, Via Santa Sofia 64, 95123, Catania, Italy^1

Dip.to di Fisica e S.d.T., Università di Messina, Ctr. Papardo 31, Messina, 98166 S. Agata, Italy^2

Dip.to Delle Civiltà Antiche e Moderne, University di Messina, Polo Annunziata, 98168, Messina, Italy^3

关键词: Ceramic samples;    Cultural heritages;    Irradiated samples;    Irradiation time;    Lead isotopic ratios;    Mediterranean basin;    Pulse durations;    Repetition rate;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/508/1/012025/pdf
DOI  :  10.1088/1742-6596/508/1/012025

来源: IOP

【 摘 要 】

A Nd:YAg laser operating at 1064 nm, 150 mJ, 3 ns pulse duration, 1-10 Hz repetition rate and 109W/cm2intensity is employed to irradiate ancient metallic and ceramic samples in high vacuum. A mass quadrupole spectrometer (MQS), operating between 1-300 amu with sensitivity better than 0.1 ppm, analyzes elements and compounds. Repetitive laser ablation removes in controlled manner the first surface layers of the irradiated samples so that the irradiation time can be correlated to the layer depth. MQS can be fixed to peculiar masses so that during the laser irradiation the mass yields can be plotted as a function of the sample depth. The technique permits to give the depth profiles of elements, chemical compounds and isotopes characterizing the composition of the analyzed samples. The analysis of ancient coins based on bronze and silver alloys and of old vitrified colored ceramics has been investigated to identify peculiar elements of the colored layers. Particularly, the lead isotopic ratios208Pb/207Pb and206Pb/207Pb were measured in bronze coins. Measurements were compared with the database of lead isotopic ratios in lead minerals extracted from old mines in the Mediterranean basin. In some cases, of special interest for Archeologists, the comparison has indicated that the lead employed for the coin production could have been extracted from mines of particular geographic sites.