The ⁴⁰Ca(α,γ)⁴⁴Ti reaction studied by in-beam γ-spectroscopy and activation

The radioactive nuclide ⁴⁴Ti is believed to be produced in the α-rich freezeout preceding supernova explosions. The γ-rays from its decay have been observed in space-based γ-observatories for the Cassiopeia A and recently also SN 1987A supernova remnants. The rates of the nuclear reactions governing the production and destruction of ⁴⁴Ti should therefore be known with high precision. Over the last years there have been various studies of the ⁴⁰Ca(α,γ)⁴⁴Ti reaction, which is dominating the ⁴⁴Ti production in supernovae.
Using the α-beam of the 3-MV Tandetron at Dresden, the strengths of ⁴⁰Ca(α,γ)⁴⁴Ti resonance triplet at 4.5 MeV laboratory α-energy has been studied by in-beam γ-spectroscopy and activation. In addition, preliminary results of resonance strengths between 3.5 and 3.8 MeV will be presented.
The irradiated samples have been analyzed in the underground laboratory Dresden Felsenkeller. The target stoichiometry has been determined by nuclear reactions and by elastic recoil detection analysis (ERDA), whereby the strength of the E_p = 1.842 MeV resonance in the ⁴⁰Ca(p,γ)⁴¹Sc reaction could be restudied.