Speaker
Dr
Jonathan Wilson
(IPN Orsay)
Description
The first results from a new program of experiments to measure nuclear level densities in the actinide region will be presented. This series of measurements has three important goals: 1) To provide systematic level density information for improving cross section calculations where direct measurements are difficult or impossible. 2) The simultaneous measurements of compound nuclear decay probabilities using the surrogate method. 3) The exploration of fine structure in actinide level densities and strength functions, of particular interest for fundamental physics reasons.
Results will be presented from recent experiments carried out at the Oslo cyclotron using 232Th(d,x) and 232Th(3He,x) transfer reactions to populate several actinide nuclei. Level densities in 231,232,233Th up to the binding energy can be extracted using the Oslo method. In addition, compound nuclear decay probabilities for 230Ac*, 232Pa*, 231Th* and 233Th* below fission thresholds have been measured using the surrogate method. For the case of 233Th*, the results can be compared with the 232Th(n,gamma) nTOF direct cross section measurements providing a good test of the validity of the surrogate method.
Author
Dr
Jonathan Wilson
(IPN Orsay)
Co-authors
Dr
Andreas Goergen
(CEA Saclay/University of Oslo)
Dr
Anne-Cecile Larsen
(University of Oslo)
Dr
Frank Gunsing
(CEA Saclay)
Prof.
Magne Guttormsen
(University of Oslo)
Dr
Mathis Wiedeking
(Lawrence Livermoore Laboratory)
Ms
Sunniva Rose
(University of Oslo)
Prof.
Sunniva Siem
(University of Oslo)
Ms
Trine Hagen
(University of Oslo)
