Determining Focusing Field Index in the Muon g-2 Experiment

Fermilab’s Muon g-2 experiment has confirmed a discrepancy between the muon’s magnetic moment and its prediction in the Standard Model, and continues to explore this phenomenon. The experiment utilizes scintillating “fiber harp” detectors to measure the motion of the muon beam. Extracting beam conditions from the fiber harps will allow simulation programs to be verified and adjusted. An extensive program has been developed to analyze fiber harp measurements and calculate the focusing field index within the storage ring under varying experimental conditions. The program utilizes a custom fitting procedure to identify the characteristic frequencies for cyclotron and betatron motion, which are used to compute the field index. This presentation focuses on the algorithmic approach used to calculate the field index and the process of grouping experimental data to estimate the uncertainty in the result.