New experiments on the key reaction in stellar helium burning: 12C(α,γ)16O

The 12C(α,γ)16O reaction is one of the key reactions in stellar evolution. To obtain better knowledge of its reaction rate at helium burning temperatures a new experiment at the Stuttgart Dynamitron accelerator has been performed using a 4π setup with nine EUROGAM HPGe detectors each equipped with an active BGO shielding. In the energy range Ecm = 1.39 - 2.80 MeV 28 angular distributions have been measured. Preliminary results are presented. As more precise measurements in the energy range Ecm≅ 0.8 - 8 MeV are needed, a further experiment with a better suited setup using four high efficient HPGe detectors on a turntable and improved targets will be started at the end of this year. In a first step angular distributions in the energy range Ecm ≅ 1- 2.5 MeV will be measured. Both experiments will be described and discussed in comparison to other methods applied to this reaction