Conclusions

Recent and anticipated developments in the precision measurement of fundamental electroweak parameters such as the Z mass provide a compelling argument to improve the precision on the electroweak coupling constant, G_F. This can be accomplished at PSI using the proposed new pulsed muon channel by a new measurement of the positive muon's lifetime. An improvement over previous work by a factor of 20 or more is anticipated, which will increase our knowledge on G_F by the same factor. Our goal of a 1 ppm measurement of $\tau_{\mu}$ can be reached with 10¹² recorded muon decays. At a machine with surface muon intensities of more than 10⁷ such as those at PSI, an artificial time structuring commensurate with the muon lifetime can be employed in order to yield a ``pulsed'' beam, averaging approximately 10⁶ muons per second. At this rate, the measurement can be made in a few hundred hours. We have outlined an experiment which is ideally suited for a pulsed beam. All sources of known systematic errors inherent in this type of measurement have been reviewed. Many are similar to those encountered and solved in the development of the muon 2 experiment at BNL. For the µLan Experiment, all systematic error estimates fall comfortably below the 1 ppm level. Barring unforeseen delays in the development of a pulsed beam at PSI, or in the construction process of the detector or WFD, the µLan Experiment can be built and carried out in a three year period.