Nuclear reactions power our Sun, and they create the chemical elements that are necessary for human life. We study radiative-capture reactions that are important for astrophysics, in precision experiments:
In Dresden using ion beams at the surface of the Earth,
at LUNA deep underground in the Gran Sasso/Italy,
collaborating at the R3B experiment at GSI/FAIR, and
in the Felsenkeller shallow underground laboratory. Together with TU Dresden we have installed a high-current 5MV accelerator there.
This page shows our ongoing projects and a brief motivation. For more details on the astrophysics, please see our review papers on LUNA and on the nuclear physics of the Sun. Some possible topics for Master's and Bachelor's theses are listed here. Further detailed information is linked through the web page you are reading now!
04.07.2019: Ceremonial start of operations in the presence of Physics Nobel Laureate Prof. T. Kajita (Photo: André Wirsig/HZDR).
Felsenkeller underground accelerator
The success of the 0.4 MV LUNA underground accelerator in Italy (with significant involvement by the HZDR group) has led to the call for higher-energy underground accelerators. One of several projects pursued worldwide includes a 5 MV Pelletron accelerator in the Felsenkeller underground facility, Dresden/Germany, co-funded by TU Dresden (Prof. Kai Zuber, supported by the German Excellence Initiative) and by HZDR.
A background intercomparison has shown that the background in a γ-ray detector in Felsenkeller is competitive with a deep-underground site, if an active veto is used. The new accelerator may be used to study solar fusion reactions such as 3He(α,γ)7Be and the reactions of helium burning such as 12C(α,γ)16O, the so-called Holy Grail of nuclear astrophysics.
Photo: HZDR/O. Killig
Access and beamtime application: Beamtime at the Felsenkeller accelerator is available through Transnational Access via ChETEC-INFRA.
Information about the application can be found here. Also, feel free to contact us.
Big Bang nucleosynthesis studied at LUNA: The 2H(p,γ)3He and 2H(α,γ)6Li reactions
PhD project Klaus Stöckel (2016-2019, DFG BE 4100/4-1), PhD thesis Michael Anders (2009-2013, DFG BE 4100/2-1, thesis)
Motivation: The motivation is driven by recent astronomical observations, on the isotopes 2H and 6Li. The stable nuclide 2H is the first product of Big Bang nucleosynthesis (BBN), in the very first few minutes of the universe. Its yield is strongly dependent on the main 2H destruction reaction, 2H(p,γ)3He. Recent and much more precise 2H observations suggest that BBN may, for the first time in two decades, constrain the cosmic baryon-to-photon number on a similar level of precision as the cosmic microwave background data from the PLANCK mission. Reports of primordial 6Li observations spawned a precise study of the main 6Li producer, 2H(α,γ)6Li.
6Li experiment at LUNA: The cross section for the main 6Li producing reaction, 2H(α,γ)6Li, was studied for the first time in the Big Bang energy window. The data suggest no significant BBN 6Li yield. The initial astronomical 6Li observations that had motivated the 6Li experiment at LUNA study have since been disputed by their own authors, in agreement with our findings.
2H experiment at LUNA: The limiting uncertainty for the BBN 2H prediction is the rate of the main 2H destruction reaction, 2H(p,γ)3He. It is currently under study at LUNA, using a windowless deuterium gas target. Two HPGe and a BGO detector are used in two separate phases to detect the γ ray from the reaction (PhD thesis of Klaus Stöckel).
2H experiment at HZDR: The higher energy range not accessible at LUNA is under study at the HZDR 3 MV Tandetron (Master's thesis of Sebastian Hammer).
- Prof. Dr. Daniel Bemmerer (Group leader)
- Dr. rer. nat. Konrad Schmidt (Staff Scientist, HZDR-High-Potential Fellow)
- Dr. rer. nat. Axel Boeltzig (ChETEC-INFRA project manager)
- Dr. Eliana Masha (DAAD postdoc)
- M. Sc. Steffen Turkat (PhD student TU Dresden, DFG: 3He(α,γ)7Be)
- M. Sc. Thomas Hensel (PhD student: Detector development for FAIR and R3B experiments)
- M. Sc. Simon Rümmler (PhD student: Ion sources at Felsenkeller)
- M. Sc. Jakub Skowronski (visiting PhD student, university of Padua)
- B. Sc. Armin Freimann (Master's student)
- B. Sc. Jonas Koch
- B. Sc. Till Lossin
- B. Sc. Max Osswald
- Dipl.-Ing. (FH) Bernd Rimarzig (Accelerator engineer)
- LUNA collaboration at Gran Sasso / Italy
- R3B collaboration at GSI/FAIR
- COST action 16117 CheTEC "Chemical Elements as Tracers of the Evolution of the Cosmos"
- ChETEC-INFRA (Chemical Elements as Tracers of the Evolution of the Cosmos – Infrastructures for Nuclear Astrophysics), European Union’s Horizon 2020 research and innovation programme under grant agreement No 101008324
- TU Dresden: K. Zuber
- VKTA Dresden: M. Köhler, D. Degering (low-level γ-counting in Felsenkeller shallow-underground laboratory)
- ATOMKI, Debrecen/Hungary: Zs. Fülöp, Gy. Gyürky, T. Szücs
- INFN Padua/Italy: C. Broggini, A. Caciolli, R. Menegazzo, R. Depalo
- INFN Genova/Italy: F. Cavanna
- Hashemite University, Zarqa/Jordan (DFG incoming fellowship for Prof. Dr. Tariq Al-Abdullah)
- Paul-Scherrer-Institut, Switzerland: D. Schumann, R. Dressler (long-lived radioisotopes for astrophysics)
- DFG Deutsche Forschungsgemeinschaft: BE 4100/4-1 (2017-2020): LUNA 2H(p,γ)3He, BE 4100/2-1 (2009-2014): LUNA 2H(α,γ)6Li and Tandetron 40Ca(α,γ)44Ti
- Helmholtz Impulse and Networking Fund (2017-2019): ERC Recognition Award
- Helmholtz Impulse and Networking Fund (2011-2016): Partner in NAVI (Nuclear Astrophysics Virtual Institute)
- DAAD German Academic Exchange Service (2015-2016): Two six-month fellowships for Dr. Francesca Cavanna and Dr. Rosanna Depalo
- INFN Italy (2009-2014): Fondo Affari Internazionali, travel support to visit Gran Sasso
- TU Dresden Graduate Academy (2014-2017): 4-month scholarships to finalize the PhD theses for Konrad Schmidt, Marcell Takács, and Louis Wagner