The ARENA project at a glance
Stars shine and evolve because nuclear reactions take place in their interiors. The physics term used to quantify the probability that a nuclear reaction occurs in a stellar environment is the nuclear reaction cross section. Due to its paramount importance in understanding stellar evolution and nucleosynthesis, cross section measurements are by far the major task in nuclear astrophysics and low-energy ion-beam accelerators, like the 5.5MV TANDEM operating at the Institute of Nuclear and Particle Physics (INPP) of the National Center for Scientific Research “Demokritos” (NCSRD), have been used for decades for this purpose, in a continuously on-going scientific challenge to search for our cosmic origins.
Nuclear Astrophysics, the domain where the proposed project belongs, was first established as a research field in 1957, when Margaret Burbidge, Geoffrey Burbidge, Willy Fowler and Fred Hoyle published their famous B2FH paper [1] in which they reviewed all of what was known about nuclosynthesis in stars. Nowadays, Nuclear Astrophysics is a vastly interdisciplinary field dealing with different problems requiring input from many different disciplines such as nuclear physics, astronomy, astrophysics, nuclear chemistry and meteoritics.
Using the TANDEM accelerator of “Demokritos” as the main experimental device, a research program related to stellar nucleosynthesis was launched in the early nineties and a vibrant nuclear astrophysics (NA) group has gradually been formed. Since then the NA group has carried out numerous measurements at the in-house Tandem as well as abroad, in collaboration with various well-established nuclear astrophysics groups and, to date, the NA group of INPP plays a worldwide leading role in stellar nucleosynthesis studies focusing, primarily, on nuclear reactions related to the understanding of the p process [2], that takes place in explosive stellar sites, such as supernovae. The group has already investigated almost 30 capture reactions and supervised more than 12 PhD and MSc theses during the last decade focusing on nuclear astrophysics.
To date, the TANDEM accelerator lab of “Demokritos” is recognized by the international scientific community as a laboratory of international stature. This status has been strongly enhanced by an EC FP7 Grant through which the project with the acronym LIBRA was funded with ≈1.5 million Euros. Thanks to LIBRA, we could acquire state-of-the art instruments and upgrade key accelerator components. A natural follow-up of LIBRA was the establishment of a national research infrastructure. Indeed, after a long-lasting evaluation procedure our proposal for a “Cluster of Accelerator Laboratories for Ion-Beam Research and Applications”, in short CALIBRA [3], has been included in the 19 research infrastructures of the corresponding first National Roadmap. As a result, CALIBRA was funded with ≈3.5 million Euros by the currently running Partnership Agreement for the Development Framework (ΕΣΠΑ 2014-2020), which is co-financed by Greece and the European Union (European Regional Development Fund – ERDF). CALIBRA is expected to complete in a year from now, when the ARENA project is expected to be launched, in case of a positive evaluation of this proposal and subsequent grant award.
Motivated by the on-going scientific challenges related to the open question how chemical species were created in cosmos, we propose herewith a project of key importance for a deeper understanding of the nucleosynthesis of trans-iron elements in stars under explosive conditions. ARENA is also the result of our long-term research experience and worldwide prominent role in the addressed scientific field. The available state-of-the art, partly unique, facilities and experimental setups at the TANDEM accelerator laboratory of “Demokritos” make the project absolutely feasible. Funding this proposal would not only provide resources to conduct forefront fundamental research, which is one of the missions of HFRI (ΕΔΙΔΕΚ), but also contribute decisively to exploitation of a Research Infrastructure for which considerable regional funds have been invested, and demonstrate this way the impact of ERDF funds in science and training of young scientists.
