Measurement of the Lamb Shift in Muonium.

This thesis describes the first measurement of the Lamb shift in n = 2 muonium. The muonium atom is a hydrogen-like bound state of two leptons ((mu)('+)e('-)), both of which are believed to be point-like particles. The point-like nature of the constituent particles simplifies and reduces the uncertainty of the application of quantum electro- dynamics (QED) to the calculation of the Lamb shift in the muonium atom. Measurements of the Lamb shift in hydrogen disagree with the predictions of theory by a few standard deviations; however, theo- retical predictions also disagree with each other, partly because of difficulties associated with the treatment of the proton structure. Thus a measurement in the muonium system of similar precision to those already made in the hydrogen system will be a valuable test of QED. This experiment is an investigation of the methods and tech- niques necessary to surmount the difficulties presented by the nature of muonium. The available number of muonium atoms is about 10('+10). times less than that of hydrogen used by Lamb in his first measure- ment. The value obtained for the n = 2 muonium Lamb shift. (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI). The uncertainty quoted is statistical at the 68% confidence level. Systematic effects were found to contribute a further 2 MHz uncertainty.