Muonium. II. Observation of the Muonium Hyperfine-Structure Interval

A full discussion is given of the microwave-spectroscopy resonance method of measuring the hyperfine-structure interval $\Delta \nu$ of the ground state of muonium, including the theoretical value for $\Delta v$, the transition frequencies, and the resonance line shape. A complete description is also given of our experimental method of measuring $\Delta \nu$ at strong magnetic field. The initial experimental results gave $\Delta \nu =4461.3\mathrm{}\pm 2.0$ MHz, in good agreement with the theoretical value $\Delta \nu =4463.282\mathrm{}\pm 0.062$ MHz. The first observations of muonium chemistry are described.