Frankfurt 2014 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
HK: Fachverband Physik der Hadronen und Kerne
HK 32: Struktur und Dynamik von Kernen
HK 32.6: Talk
Wednesday, March 19, 2014, 18:00–18:15, HZ 5
Preparations for an optical access to the lowest nuclear excitation in 229Th * — •Lars v.d.Wense1, Benedict Seiferle1, Peter Thirolf1, and Mustapha Laatiaoui2 — 1Ludwig-Maximilians-Universität München — 2GSI Helmholtzzentrum für Schwerionenforschung GmbH
The isomeric lowest excited nuclear level of 229Th has been indirectly measured to be 7.6±0.5 eV (163±11 nm)[1]. In order to improve the accuracy as prerequisite of an all-optical control, 229mTh is populated via a 2% decay branch in the α decay of 233U. The Thorium ions are extracted and cooled with the help of a buffer gas stopping cell and an RFQ-cooler. In order to suppress accompanying α decay chain products other than 229Th, a quadrupole mass spectrometer (QMS) is used, performance and extraction efficiency measurements were performed. Following the QMS, the Thorium isomers will be collected on a 50 µ m micro electrode. The decay of these isomers can then be detected using deep UV optics [2], presently in the phase of preparation and adjustment. Newest results will be presented.
[1] B.R. Beck et al., PRL 98, 142501 (2007).
[2] L. v.d.Wense et al., JINST 8 P03005 (2013).
* Supported by DFG Grant number TH956/3-1.