All (2002-Present)  SS21  WS21  SS22  WS22  SS23  WS23  SS24

 Karl Franzens University Graz

Graz University of Technology 

Resonant (laser) excitation of the Thorium-229 nucleus
Prof. Thorsten Schumm
Vienna University of Technology
16:15 - 17:15 Tuesday 16 April 2024 TUG

Among all known isotopes, Thorium-229 has the lowest nuclear excited state, only 8.4 eV above the ground state.
This so-called “isomer” is accessible to VUV laser excitation and a plethora of applications at the interface of atomic and nuclear physics have been proposed, including a nuclear clock, a gamma laser and a sensitive detector for variations of fundamental constants.
After decades of attempts to determine the exact isomer energy and other nuclear properties, we report on two experiments which resonantly excite the isomer, through X-ray pumping via the 2nd nuclear state at 29 keV and direct excitation using a VUV laser.
This marks the transfer of precision laser spectroscopy into the field of nuclear physics.