Figure 2 : Experiment sequence and measurement of the cyclotron frequency.

From: Sixfold improved single particle measurement of the magnetic moment of the antiproton

Figure 2

(a) We first centre the particle in the trap by cooling the magnetron motion to E/kB<4 mK. Then we measure the modified cyclotron frequency ν+,AT,1. Subsequently we scan the Larmor resonance νL,AT and then measure the modified cyclotron frequency again ν+,AT,2. Afterwards we re-cool the magnetron motion. For a more detailed explanation of the experiment sequence we refer to the text. (b) Sequence of axial frequency measurements of 30 s averaging time while a radial dipolar drive at νrf,k is applied. The drive frequency is adjusted after each 10 measurements. Once the drive excites cyclotron transitions νrf,kν+,cut, the axial frequency fluctuation increases. (c) Projection of axial frequency data to axial frequency fluctuation Ξz(νrf). The error bars represent the standard deviations of the individual measurements. The red and green vertical lines indicate the determined mean value ν+,cut and its 95% confidence level uncertainties, respectively, the blue solid line is a fit based on the the data-analysis described in the text.