Magnetic Field Determination for Run 1 of the Fermilab Muon g-2 Experiment

Abstract

The muon $g-2$ experiment at Fermilab aims to measure the anomalous magnetic moment of the muon, $a_{\mu}$, to a precision of 140 parts per billion (ppb). The measurement will shed light on the current $>$3$\sigma$ deviation between Standard Model calculations and the previous measurement made at Brookhaven National Laboratory, either resolving the discrepancy or confirming it to $>$5$\sigma$. In the muon $g-2$ experiment, muons are stored in a magnetic storage ring and their decays are observed. In order to reach the precision goal, the magnetic field experienced by the muons must be known with an uncertainty of \SI{70}{ppb} or less. To this end, the magnetic field was shimmed to unprecedented homogeneity. Two measurement systems are used to track the evolution of the magnetic field. This dissertation describes the motivations for the $g-2$ experiment, gives a brief overview of the experimental principles, introduces the magnetic field measurement hardware, describes the magnetic field shimming process, and presents an analysis of the magnetic field tracking for data collected in spring 2018 during run 1 of the Fermilab muon $g-2$ experiment.