Hannover 2020 – wissenschaftliches Programm

Die DPG-Frühjahrstagung in Hannover musste abgesagt werden! Lesen Sie mehr ...

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MS: Fachverband Massenspektrometrie

MS 12: Accelerator Mass Spectrometry and Applications III

MS 12.2: Vortrag

Donnerstag, 12. März 2020, 14:15–14:30, f128

The difficulty to measure the neutron capture cross section of ²³⁵U at thermal energies — Anton Wallner^1,2, Peter Schillebeeckx³, Stefaan Pomme⁴, Jan Wagemans⁴, Jan Heyse³, Roberto Capote⁵, Michaela Froehlich², Peter Steier⁶, Zsolt Revay⁷, Christian Stieghorst⁷, Ulli Koester⁸, Thorsten Soldner⁸, and •Tobias Jenke⁸ — ¹Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany — ²The Australian National University, Canberra, Australia — ³JRC-Geel, Retieseweg 111 B-2440 Geel, Belgium — ⁴SCK CEN, Mol, Belgium — ⁵Nuclear Data Section, IAEA, Vienna — ⁶VERA laboratory, Univ. of Vienna, Austria — ⁷FRM II, TU Munich, Germany — ⁸Institut Laue-Langevin, Grenoble, France

The recommended *highly precise* cross-section value for ²³⁵U neutron-capture at thermal energies is largely based on the difference from total and competing cross-sections of ²³⁵U. Despite its importance and high value (100 barn), direct measurements of (n,γ) are rare (only two exist for thermal energies) and exhibit large uncertainties. The reason is the difficulty to measure the characteristic radiation of the reaction product ²³⁶U within a dominant fission background (²³⁶U has a long half-life of 23.4 Myr).

For this reasons, we started a project with a new method utilizing different neutron fields to evaluate its energy dependence in the low energy region. We use a combination of neutron activation and subsequent accelerator-mass-spectrometry (AMS) for direct atom counting of the reaction product ²³⁶U.