Preparation of carbon samples for 14C dating by the AMS technique
The Radiocarbon Laboratory of the Rudjer Bošković Institute (RBI) in Zagreb has long experience in 14C dating. Since 1969 we have used the gas proportional counter technique with sample conversion to methane, and since 2002 the liquid scintillation counting technique with either benzene synthesis or direct absorption of CO2 obtained from the sample. These techniques require 2-5 g of carbon. In order to expand our activities to very small samples of the size of mg, we developed preparation of carbon (graphite) from small samples for 14 C dating and to measure the prepared graphite targets in one of the AMS (Accelerator Mass Spectroscopy) facilities in Europe, namely SUERC (Scottish Universities Environmental Research Centre, University of Glasgow, UK). To achieve this, we trained our staff in the SUERC AMS laboratory, for a short-term temporary job position for software specialist who would upgrade our preparation and measurement systems. We hosted an expert in AMS dating (from SUERC) who transferred his knowledge and experience, and performed intercomparison studies of samples prepared in our Laboratory and in the SUERC. We asked also for some small pieces of equipment, spare parts, standard samples of known 14C activity and chemicals, with the aim of reinforcing research potential of the Laboratory. The proposal was structured into 6 work packages. The expected results are a fully operational graphite preparation line in the RBI Laboratory; establishment of co-operation with the UGLA-SUERC Laboratory for measurements of the graphite targets using their accelerator; training and career development of researchers in Croatia; improved competitiveness of the RBI Laboratory for future international projects; better opportunities for integration into the European Research Area (ERA), and creation of improved market opportunities for the research centre in WBC. Scottish Universities Environmental Research Centre (SUERC) of the University of Glasgow (UGLA) was the subcontractor on the Project with the major task of measurement of graphite samples prepared at the RBI and participation in the interlaboratory intercomparison. Also, the specialized trainings were realized at SUERC and their experts visited the RBI laboratory. A good co-operation has been established between RBI and SUERC, the experience of the SUERC staff gained in the development of their line, as well as in the day-to-day preparation and measurement routine, helped us in faster implementation of a new system and it is foreseen to continue this co-operation also in future.