The radio isotope Thorium-229 is expected to present a remarkably low-energy excited (isomer) state of the nucleus which is expected around 10 eV. It might hence be possible to directly excite the atomic nucleus with UV (laser) radiation, creating a bridge between atomic and nuclear physics. The (expected) narrow line width of the transition and the intrinsic robustness of nuclear transitions to external fields makes it a promising candidate for a new frequency standard - a "nuclear clock". In this presentation we will review the current state of knowledge on the low-energy nuclear transition in Thorium-229 and the ongoing quest to measure it’s exact energy.
Wolfgang Lerche / TH-SP