The “Lilliput” experimental set-up at INFN: state of art and future developments
Dr Serena Barone1,2, Vera Bernardoni3,4, Giulia Calzolai1, Massimo Chiari1, Federica Crova3,4, Alice Forello3,4, Lucia Liccioli1, Franco Lucarelli1,2, Silvia Nava1,2, Gianluigi Valli3,4, Roberta Vecchi3,4, Mariaelena Fedi1
1Istituto Nazionale Di Fisica Nucleare, sezione di Firenze, Florence, Italy, 2Università degli studi di Firenze, Florence, Italy, 3Istituto Nazionale Di Fisica Nucleare, sezione di Milano, Milan, Italy, 4Università degli Studi di Milano-Bicocca, Milan, Italy
In the last few years, minimising the invasiveness of the analysis has been one the most relevant research topics in the field of radiocarbon, when it is applied both to Cultural Heritage and to environmental contexts. At INFN-LABEC in Florence, we built up a new experimental set-up, aiming at reducing the necessary mass of graphite for the 14C concentration measurement. Indeed, we are now able to deal with samples of few tens of µg of carbon, while the typical masses collected at the end of the “large” graphitization process are about 700 µg.
We installed new graphitization reactors, reducing their volumes to favour the graphitization reaction by increasing the collected pressure. New reactors were equipped with a small quartz tube used as the “hot” part and a silver cold finger. We also designed and assembled dedicated ovens and small Peltier-based devices, used to reach the temperature needed to trigger the reaction and to trap the unwanted water produced during the graphitization reaction, respectively. Moreover, we installed new miniature pressure gauges, sensitive to low pressures, and we assembled a home-made data acquisition system based on an Arduino board.
As far as the optimization of the AMS measurements in the Tandem accelerator, we performed “Lilliput” beam runs using different operating conditions, especially considering the sputtering ion source and the injection timings of the three carbon isotope masses into the accelerator tube.
The preliminary tests on the new “Lilliput” experimental set-up were successful and nowadays small. samples are routinely measured, especially in the field of Cultural Heritage, e.g. on charcoals, papyri and bone collagen collected from challenging contexts.
Our next goal is to assemble a new set-up at INFN Milan, specifically built for environmental analysis. This new set-up will allow us to reconstruct the emitting sources of the PM carbon fractions. This information is important to collect data on fossil fuel combustion, biomass burning, and natural contributions to the total burden of carbonaceous aerosol in the atmosphere so as to monitor their effects on health and environment.
M.Sc. in Science for Cultural Heritage, Ph.D. in Chemistry – Cultural Heritage curriculum – at the University of Florence, she is currently working as a researcher at INFN-CHNet, Florence. Her research is focused on Radiocarbon Dating, with particular attention to C-14 concentration measurements of samples with very small mass by AMS.”