Precision Determination of g-Factors with an Atomic Fountain Clock

• Applicant: Privatdozent Dr. Robert Wynands
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2007 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 35368585

• Final Report Year: 2012

Final Report Abstract

Goal of the project was the determination of the g-factor of the 133Cs nucleus in a neutral atom, using the exquisite precision and stability of an ensemble of two primary atomic fountain clocks located side by side in PTB's clock halL Estimates showed that a hundred-fold improvement over the existing uncertainty should have been possible. In the end, interesting and previously unknown systematic effects prevented us from reaching that goal, as we had to accept after trying various approaches. In effect, instead of using the fountain clock know-how to measure the nuclear g-factor we learned important facts about fountain clocks, with immediate consequences (improvements!) for the national and international time scales.

Publications

• The PTB fountain clock ensemble: Preliminary characterization of the new fountain CSF2. 7th Symposium on Frequency Standards and Metrology, Asilomar (USA), Oct 2008
  S. Weyers, V. Gerginov, N. Nemitz, R. Schröder, R. Wynands
  
• First uncertainty evaluation of the new caesium fountain CSF2 at PTB. European Frequency and Time Forum (EFTF) and IEEE International Frequency Control Symposium (FCS), Besannen (FR), April 2009
  V. Gerginov, N. Nemitz, S. Weyers, R. Schröder, D. Griebsch, R. Wynands
  
• Investigating Δm = ±1 transitions in a caesium fountain clock - challenges in precision measurements of the g-factor ratio. European Frequency and Time Forum (EFTF), Noordwijk (NL), April 2010
  N. Nemitz, V. Gerginov, S. Weyers, R. Wynands
  
• Recent improvements and current uncertainty budget of PTB fountain clock CSF2. European Frequency and Time Forum (EFTF), Noordwijk (NL), April 2010
  V. Gerginov, N. Nemitz, D. Griebsch, M. Kazda, R. Li, K. Gibble, S. Weyers
  
• Uncertainty evaluation of the caesium fountain clock PTB-CSF2. Metrologia 47, 65-79 (2010)
  V. Gerginov, N. Nemitz, S. Weyers, R. Schröder, D. Griebsch, R. Wynands
  
• Using (ΔF= 1, ΔmF= 1) transitions as a diagnostic tool for atomic fountain clocks. International Conference on Atomic Physics (ICAP), Cairns (AU), July 2010
  N. Nemitz, V. Gerginov, S. Weyers, R. Wynands
  
• (ΔF= 1, Δmf = ±1) transitions as a diagnostic tool for atomic fountain clocks. European Frequency and Time Forum (EFTF) and IEEE International Frequency Control Symposium (FCS), San Francisco (USA), April 2011
  N. Nemitz, V. Gerginov, S. Weyers, R. Wynands, Using
  
• Atomic trajectory characterization in a fountain clock based on the spectrum of a hyperfine transition. Physical Review A (2012)
  N. Nemitz, V. Gerginov, R. Wynands, S. Weyers
  (See online at https://doi.org/10.1088/0026-1394/49/4/468)
• Distributed cavity phase frequency shifts on the caesium fountain PTB-CSF2. Metrologia 49,82-87 (2012)
  S. Weyers, V. Gerginov, N. Nemitz, R. Li, K. Gibble
  (See online at https://doi.org/10.1088/0026-1394/49/1/012)