Project description
Highly Charged Thorium-229 nuclear clock could revolutionise metrology
Thorium-229 stands out amongst over 3 000 known nuclides owing to its remarkably low excitation energy, making it an ideal candidate for frequency metrology. Its performance surpasses that of current atomic clocks. Funded by the European Research Council, the HITHOR project proposes an innovative approach to develop a nuclear clock using thorium-229. The methodology involves creating a no-electron bare-nucleus clock with trapped fully ionised 229Th90+, eliminating external perturbations from electrons. By adding a single electron to the nucleus, research will leverage nuclear hyperfine mixing, thereby significantly accelerating nuclear decay and enhancing laser excitation. Project experiments will pave the way towards high-precision vacuum ultraviolet laser spectroscopy and the development of a nuclear clock based on ultra-cold, isolated highly-charged thorium-229 ions.
Objective
"Among the more than 3000 nuclides that are naturally occurring or that have been artificially synthesized, thorium-229 is truly exceptional. Its remarkably low excitation energy makes it the ideal candidate for nuclear frequency metrology, surpassing current atomic clocks. Such a ""nuclear clock"" opens doors to fundamental physics, testing time-variations of constants and exploring the enigma of dark matter.
Within HITHOR a conceptually novel methodology towards such a clock is proposed, eventually leading to a no-electron “bare-nucleus” clock with trapped fully ionized 229Th90+ where all external perturbations from surrounding electrons are absent. Highly-ionized 229Th will be established as a distinctive laboratory for scientific explorations at the interface of atomic electrons and the nucleus.
By adding a single electron to the nucleus, the unique effect of nuclear hyperfine mixing (NHM) is unlocked. Induced by the strong magnetic field of this one electron, a vast acceleration of the nuclear decay by up to a millionfold is triggered. Hence, for one-electron 229Th89+ laser excitation of the nucleus as well as the reemission of photons are each enhanced by up to this factor of a million. To date, laser excitation of the nucleus hasn’t been accomplished. NHM will help to overcome this obstacle and exploited as a booster towards 229Th laser excitation and a corresponding nuclear clock.
HITHOR will be realized at the ion storage and trapping facilities at GSI in Darmstadt, the only laboratory worldwide where highly ionized 229Th can be synthesized in flight, decelerated, and finally trapped at rest. At GSI and its Helmholtz Institute Jena, I will bring together the extraordinary expertise of in-house scientists from the various disciplines required to tackle the challenges. Initial experiments will pave the path towards high-precision VUV laser spectroscopy of few- or no-electron 229Th, and ultimately towards a single-ion quantum logic nuclear clock."
Fields of science
- natural sciencesphysical sciencesastronomyastrophysicsdark matter
- natural sciencesphysical sciencesnuclear physicsnuclear decay
- natural sciencesphysical sciencesopticslaser physics
- natural sciencesphysical sciencestheoretical physicsparticle physicsphotons
- natural sciencesphysical sciencesopticsspectroscopy
Keywords
Programme(s)
- HORIZON.1.1 - European Research Council (ERC) Main Programme
Topic(s)
Funding Scheme
HORIZON-ERC - HORIZON ERC GrantsHost institution
64291 Darmstadt
Germany