Technische Universität München
Experimental confirmation of nuclear fusions in the sun is awarded with the Giuseppe and Vanna Cocconi Prize by the European Physical Society
TECHNICAL UNIVERSITY OF MUNICH
Corporate Communications Center
Phone: +49 89 289 10510 - e-mail: presse@tum.de - web: www.tum.de
This text on the web: https://www.tum.de/nc/en/about-tum/news/press-releases/details/36709/
High resolution images: https://mediatum.ub.tum.de/1579892
NEWS RELEASE
Borexino team receives prestigious Cocconi award
Renowned award for experimental confirmation of nuclear fusions in the sun
For their groundbreaking observations of solar neutrinos, with which the fusion reactions inside the sun could be experimentally proofed for the first time, the team of the Borexino collaboration receives the prestigious Giuseppe and Vanna Cocconi Prize. Every two years, the European Physical Society awards it to an outstanding discovery in astro-particle physics and cosmology of the past 15 years.
In 2018, after more than ten years of observing solar neutrinos, the Borexino experiment presented an overall study of the pp chain, the most important fusion process in the sun. The study confirmed for the first time the theoretical ideas about the energy production in our sun.
Recently, after years of efforts, the Borexino collaboration was also able to observe the second fusion process, the CNO cycle. Both measurements experimentally prove the hypothesis about how the sun works put forward in the 1930s.
TUM emeritus Prof. Franz von Feilitzsch, Prof. Lothar Oberauer and Prof. Stefan Schönert, all working at the Chair of Experimental Astroparticle Physics of the Technical University of Munich (TUM), made significant contributions to the measurements.
From hydrogen to helium
According to the physical model, around 99 percent of the solar energy results from a chain of fusion reactions that begins with four hydrogen nuclei and ends with the production of helium (proton-proton chain, pp chain). The only direct evidence of this process lies in the observation of the neutrinos that are emitted during these reactions.
The original scientific goal of Borexino was to measure neutrinos that are created in the pp chain when 7Be is fused. However, the observation of these low-energy solar neutrinos places high demands on the sensitivity and purity of the experiment.
Sophisticated data analysis
"The key to the success of Borexino was that we managed to almost completely eliminate radioactive trace elements in the detector material," says Prof. Lothar Oberauer. “The Borexino collaboration has broken new ground here and achieved an unprecedented level of purity. The remaining background radiation could be identified by using sophisticated data analysis methods. "
In this way, since the start in 2007, Borexino has managed to answer questions that went well beyond the initial goal. Most recently, the collaboration succeeded in demonstrating the CNO cycle, that had been proposed by Hans Bethe and Carl Friedrich von Weizsäcker in 1939. About one percent of the solar energy stems from this cycle.
"At first I would not have thought it possible that we would ever observe CNO neutrinos with Borexino, since the background signals appeared too high," says Stefan Schönert. Apart from solar neutrinos, Borexino was also able to measure neutrinos from inside the earth and answer questions about the earth's heat balance.
Groundbreaking observations
The European Physical Society now honors the scientists of the Borexino experiment with this year's Giuseppe and Vanna Cocconi Prize for their ‘groundbreaking observations of solar neutrinos from the pp and the CNO chains that provided unique and comprehensive tests of the sun as a nuclear fusion engine' as the committee states.
TUM Emeritus Prof. Franz von Feilitzsch, who was one of the experiment’s initiators 30 years ago, is very pleased: “It was a courageous decision by the INFN to support such a challenging experiment on a permanent basis. We had a great cooperation with our European, Russian and American colleagues. The outstanding success of Borexino is not least due to a great number of young scientists.”
The online award ceremony will take place on 26 July 2021 during the high energy physics conference of the European Physical Society.
Contact:
Chair for Experimental Physics and Astrophysics (E15)
Technical University of Munich
James-Franck-Str. 1, 85748 Garching, Germany
Prof. Dr. Stefan Schönert
Tel.: +49 89 289 12522 – E-Mail: schoenert@ph.tum.de
Prof. Dr. Lothar Oberauer
Tel.: +49 89 289 12509 – E-Mail: lothar.oberauer@tum.de
Web: http://www.e15.ph.tum.de/ – http://www.e15.ph.tum.de/research_and_projects/borexino/
More Information:
The Borexino experiment is carried out by 130 scientists from universities and scientific institutions in Italy, France, Germany, Great Britain, Ukraine, Russia, Poland and the USA. In Germany Forschungszentrum Jülich, University of Mainz, University of Hamburg as well as the Technical Universities of Dresden and Munich are involved.
In order to shield the experiments from cosmic background radiation the Borexino experiment is operated in the Gran Sasso underground laboratory which is carved into the rock deep under the mountains of the Italian Gran Sasso massif. The laboratory is part of the Italian National Institute for Nuclear Physics (INFN).
Previous press releases about the Borexino experiment:
https://www.tum.de/nc/en/about-tum/news/press-releases/details/36337/
https://www.tum.de/nc/die-tum/aktuelles/pressemitteilungen/details/35047/
https://www.tum.de/nc/die-tum/aktuelles/pressemitteilungen/details/31757/
The Technical University of Munich (TUM) is one of Europe’s leading research universities, with more than 600 professors, 45,000 students, and 10,000 academic and non-academic staff. Its focus areas are the engineering sciences, natural sciences, life sciences and medicine, combined with economic and social sciences. TUM acts as an entrepreneurial university that promotes talents and creates value for society. In that it profits from having strong partners in science and industry. It is represented worldwide with the TUM Asia campus in Singapore as well as offices in Beijing, Brussels, Mumbai, San Francisco, and São Paulo. Nobel Prize winners and inventors such as Rudolf Diesel, Carl von Linde, and Rudolf Mößbauer have done research at TUM. In 2006, 2012, and 2019 it won recognition as a German "Excellence University." In international rankings, TUM regularly places among the best universities in Germany. www.tum.de