Nuclear reactions for astrophysics, studied at LUNA and in Dresden (finished projects)
On this history page we summarize finished projects, and present a list of alumni. See our homepage for up-to-date information on running projects and a current list of people. See the list of theses for a list of ongoing and completed thesis work.
Nucleosynthesis in the Big Bang: 2H(α,γ)6Li
PhD project Michael Anders (2009-2013)
Motivation: The 2H(α,γ)6Li reaction controls the production of 6Li in big-bang nucleosynthesis, in the very first minutes of existence of our universe. In some very old stars, lithium-6 is found in quantities greatly exceeding the value predicted by standard big-bang nucleosynthesis calculations.
Experiment: The first experiment studying this reaction directly at big-bang energies is ongoing at LUNA. Further details on the 2H(α,γ)6Li experiment can be found here.
LUNA = Laboratory Underground for Nuclear Astrophysics
The international LUNA collaboration aims to provide nuclear data directly at energies of astrophysical interest and thus remove the need for theoretical extrapolations. LUNA is located deep underground in the Gran Sasso laboratory in Italy. The Gran Sasso mountain strongly reduces the γ-ray laboratory background, enabling sensitive experiments.
Hydrogen burning in massive stars: 15N(p,γ)16O
Motivation: The 15N(p,γ)16O reaction lies at the branching point between CNO cycles I and II, controlling the amount of nucleosynthetic material passed to the higher CNO and subsequent NeNa and MgAl cycles.
Experiment at LUNA: The cross section has been measured with nitrogen targets of natural isotopic composition (0.37% 15N), see below paper. Follow-up experiments at LUNA have been performed with enriched 15N targets, using first a HPGe and then a 4π BGO summing detector.
- J. Phys. G 2009 Bemmerer et al.
- Phys. Rev. C 2010 LeBlanc et al.
- Astronomy & Astrophysics 2011 Caciolli et al.
Thermometer of the center of the Sun: 3He(α,γ)7Be reaction
Motivation: The flux of solar 8B neutrinos has been measured with 3.5% precision (2006) by the SuperKamiokande neutrino detector in Japan. The uncertainty in the predicted 8B neutrino flux is dominated by the 3He(α,γ)7Be reaction.
Experiment at LUNA: The 3He(α,γ)7Be reaction has been studied experimentally with a systematic uncertainty as low as 3.0%, decisively improving the precision of the prediction:
- Phys. Rev. Lett. 2006 Bemmerer et al.
- Phys. Rev. C 2007 Gyürky et al.
- Phys. Rev. C 2007 Confortola et al.
- Nucl. Phys. A 2008 Costantini et al.
γ-ray background measurements at LUNA
- Study of the γ-ray background at LUNA for Eγ > 3 MeV
- Study of the γ-ray background at LUNA for Eγ < 3 MeV
- Study of the γ-ray background at LUNA with an escape-suppressed detector
A similar background study is ongoing at Felsenkeller.
Alumni (see also separate page with list of theses)
- Pedro Calvo Portela (Univ. Complutense Madrid, HZDR summer student 2015)
- Dr. rer. nat. Konrad Schmidt (PhD thesis, DFG and TU Dresden GA: 40Ca(α,γ)44Ti)
- Dipl.-Phys. Klaus Stöckel (Diploma student: 12C(p,γ)13N at 3MV Tandetron)
- Dipl.-Phys. Stefan Gohl (Diploma student: SiPMs for NeuLAND)
- B.Sc. Felix Ludwig (Bachelor's student on characterization of the RF ion source for Felsenkeller)
- B.Sc. Martin Serfling (Bachelor's student on the 14N(p,γ)15O cross section)
- Dr. rer. nat. Michael Anders (PhD thesis on 2H(α,γ)6Li at LUNA)
- B. Sc. Johannes Krause (Bachelor's student on gas target for Felsenkeller accelerator)
- B. Sc. Jonas Wielicki (Bachelor's student on CAMAC control for Felsenkeller accelerator)
- Dipl.-Phys. Marie-Luise Menzel (Diploma thesis on 22Ne(p,γ)23Na at LUNA 2011-2012)
- Mirco Dietz (Bachelor student on 40Ca(α,γ)44Ti at HZDR 2012)
- M. Sc. Dmitry Yakorev (NeuLAND MRPC detector development; Russia)
- Marcell Takacs (HZDR summer student from Debrecen/Hungary on 40Ca(α,γ)44Ti and 44Ti(α,p)47V, July-September 2012)
- Dr. rer. nat. Michele Marta (PhD student 2007-2011; PhD thesis defended at TU Dresden in November 2011; now postdoc at GSI)
- Prof. Dr. Tariq Al-Abdullah (Hashemite University, Zarqa/Jordan, DFG fellow at HZDR from June-September 2011, and again June-August 2012 and June-August 2013)
- Dipl.-Phys. Erik Trompler (Master's student at TU Dresden, 2008-2009, thesis download here)
- M. Sc. Tamás Szücs (Herbert Quandt fellow from Debrecen/Hungary April-Sept 2009, paper here)
- András Szepesi (Herbert Quandt fellow March-July 2010)
Financial support (finished projects)
Deutsche Forschungsgemeinschaft DFG BE 4100/2-1 (2009-2014, study of 2H(α,γ)6Li at LUNA and 40Ca(α,γ)44Ti at HZDR)
- Deutsche Forschungsgemeinschaft, DFG BE 4100/3-1 (incoming fellowship for Prof. Dr. Tariq Al-Abdullah, Hashemite University, Zarqa/Jordan)
- European Union, FP7 SPIRIT, transnational access (2009-2010)
- European Union, FP6 ILIAS, transnational access (2006-2009)
- European Union, FP6 AIM, transnational access (2008-2009)
- Herbert-Quandt-Foundation (Fellowships for Tamás Szücs April-September 2009, András Szepesi April-July 2010)