We did it !

We are overly excited to announce:

Our teams from TU Wien and PTB Braunschweig successfully managed the laser excitation of the Th-229 Nucleus.

The 8.4 eV nuclear isomer state in Th-229 is resonantly excited in Th-doped CaF2 crystals using a tabletop tunable laser system. A resonance fluorescence signal is observed in two crystals with different Th-229 dopant concentrations, while it is absent in a control experiment using Th-232. The nuclear resonance for the Th4+ ions in Th:CaF2 is measured at the wavelength 148.3821(5) nm, frequency 2020.409(7) THz, and the fluorescence lifetime in the crystal is 630(15) s, corresponding to an isomer half-life of 1740(50) s for a nucleus isolated in vacuum. These results pave the way toward Th-229 nuclear laser spectroscopy and realizing optical nuclear clocks.

Read the full paper here.

You can also read the press articles in German here or here.

We are celebrating this major breakthrough that is now making way for new even more precise technologies – a Thorium nuclear Clock for example.