PARIS - Proton cApture Reactions in type Ia Supernovae

• Applicant: Dr. Kerstin Sonnabend
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: from 2012 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 225863585

The question about the origin of the heavy elements is one of the major unsolved problems concerning the physics of the Universe. While the overall picture seems clear, a closer inspection of this complex topic has opened up many challenging questions. An especially puzzling case is the production of about 35 proton-rich, low-abundant isotopes, which cannot be produced in neutron capture reactions, the so-called p nuclei. The lightest ones might be produced by a series of proton capture reactions occurring in type Ia supernovae. A precise experimentally based knowledge of the relevant reaction cross sections is the key to investigate whether this is a realistic picture. If so, the nucleosynthesis of the p nuclei can be used to observe the interior of type Ia supernovae as it constrains their astrophysical parameters and, therefore, to serve as a tool to better understand the physics of these cosmological standard candles. This Emmy Noether proposal aims at establishing the experimental techniques to investigate these proton capture reactions with high intensity proton beams. The production of the most abundant p nucleus 92Mo in type Ia supernovae will be studied by measuring the reactions 90Zr(p,γ) and 91Nb(p,γ) with a high efficient 4π BaF2 calorimeter at the FRANZ facility at Goethe University Frankfurt. The needed extensions of FRANZ and the development of high-power, in case of 91Nb unstable, samples will be performed. Afterwards, FRANZ will be a worldwide unique facility to measure proton-induced reactions with highest proton intensities.

• DFG Programme: Independent Junior Research Groups
• Major Instrumentation: Strahljustierungs- und Beobachtungseinrichtung
• Instrumentation Group: 0130 Spezielle Magnete (Strahlführungsmagnete, Höchstfeldmagnete, außer 010-012 und 683)