@article{Petley1974APO,
title={A precise omegatron measurement of μp/μ N},
author={B. Petley and K. Morris},
journal={Journal of Physics A: Mathematical, Nuclear and General},
year={1974},
volume={7},
pages={167-182}
}

Journal of Physics A: Mathematical, Nuclear and General

The value obtained for the proton magnetic moment in nuclear magnetons was 2.7927748+or-0.0000020 (0.72 ppm) without the diamagnetic shielding correction. Measurements were made with a quadrupole omegatron at flux densities of 0.47, 0.94 and 1.41 T. More than 400 sets of measurements were made using H2+, HD+, D2+, 4He+ ions and protons.