Publications by authors named "O Forstner"

Stable ^{205}Tl ions have the lowest known energy threshold for capturing electron neutrinos (ν_{e}) of E_{ν_{e}}≥50.6  keV. The Lorandite Experiment (LOREX), proposed in the 1980s, aims at obtaining the longtime averaged solar neutrino flux by utilizing natural deposits of Tl-bearing lorandite ores.

View Article and Find Full Text PDF
Article Synopsis
  • Radioactive nuclei that live for millions of years help us understand the Sun's formation and the nucleosynthesis happening when it was born, with lead (Pb) being a key example.
  • Recent measurements of the weak decay of ionized thallium (Tl) provided a more accurate half-life, which was found to be 4.7 times longer than previously thought, thus reducing uncertainty in our calculations.
  • Using these improved decay rates, researchers calculated lead yields in asymptotic giant branch (AGB) stars, confirmed isolation times for solar material, and validated the theory that the Sun formed in a long-lived molecular cloud.
View Article and Find Full Text PDF

The nuclear two-photon or double-gamma (2γ) decay is a second-order electromagnetic process whereby a nucleus in an excited state emits two gamma rays simultaneously. To be able to directly measure the 2γ decay rate in the low-energy regime below the electron-positron pair-creation threshold, we combined the isochronous mode of a storage ring with Schottky resonant cavities. The newly developed technique can be applied to isomers with excitation energies down to ∼100  keV and half-lives as short as ∼10  ms.

View Article and Find Full Text PDF

One of the most important properties influencing the chemical behavior of an element is the electron affinity (EA). Among the remaining elements with unknown EA is astatine, where one of its isotopes, At, is remarkably well suited for targeted radionuclide therapy of cancer. With the At anion being involved in many aspects of current astatine labeling protocols, the knowledge of the electron affinity of this element is of prime importance.

View Article and Find Full Text PDF

New techniques for suppression of atomic isobars in negative ion beams are of great interest for accelerator mass spectrometry (AMS). Especially small and medium-sized facilities can significantly extend their measurement capabilities to new interesting isotopes with a technique independent of terminal voltage. In a new approach, the effect of continuous wave laser light directed towards the cathode surface in a cesium sputter ion source of the Middleton type was studied.

View Article and Find Full Text PDF