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 Wallner1,2, 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.