Event Details

The development of time keeper devices has a long history. From the invention of traditional pendulum clocks to modern atomic clocks, the accuracy and stability of the clocks have both improved a lot. Nowadays, the most accurate atomic clock (the Strontium lattice clock in NIST) has uncertainty of 2*10-18. The nuclear clock is one of the promising next generation clocks, with its accuracy predicted to be 10-19. Thorium-229 is the only candidate, which has a nuclear transition of 7.6+-0.5eV, can be used to build the next generation nuclear clock. However, the exact energy level and lifetime of this nuclear excited state has never been precisely determined. Several groups in the world are currently working on the measurement of this nuclear transition. In this talk, I will introduce the status and recent development of the Th-229 isomeric state measurement.