Summary

In this thesis, we have reported a new approach in $\mu$CF studies, viz the time-of-flight method using an atomic beam of muonic tritium. With this new technique we have made measurements on $\mu t$scattering as well as epithermal $d\mu t$ resonant formation, which have been quantitatively studied for the first time.

Various experimental challenges have been overcome in order to complete the experiments. Technical contributions of this thesis to the field of $\mu$CF studies include:

1.

Characterization of target layer thickness and uniformity to an accuracy of up to a few tens of nanometers, and the evaluation of effective average thickness using the muon beam profile obtained from the MWPC imaging.

2.

New methods for determinig the stopping fraction, such as the absolute amplitude method via delayed electron coincidence, and the relative amplitude with electron energy cuts.

3.

Considerations of resonant scattering in the $\mu$CF processes with detailed expressions for scattered $\mu t$ energy.

The physics results of this thesis can be summarized as follows.

1.

We have observed an emission of muonic tritium in vacuum via imaging of muon decay electrons. From the position and the time of muon decay, information of the $\mu t$ energy was obtained, enabling us to spectroscopically establish the existence of the Ramsauer-Townsend effect in $\mu t + p$ interactions. The energy of the RT minimum was measured to be $13.6\pm 1.0$ eV, in fair agreement with quantum three body calculations by Chiccoli et al. [17].

2.

Using the $\mu t$ beam, we have confirmed theoretical $\mu t+ d$scattering cross sections [17] to the 10% level by measuring the attenuation of $\mu t$ through deuterium. Comparisons with Monte Carlo simulations, assuming different scattering angular distributions, also confirmed the importance of p-wave scattering in the $\mu t+ d$interaction, giving angular momentum information on the loosely bound state of the $d\mu t$ molecule.

3.

The existence of the predicted large resonance in $\mu t + D_2$ collisions was directly confirmed for the first time. Our results of the resonance strength correspond to a peak rate of s^-1when the resonance width given by Faifman is assumed. This is more than an order of magnitude larger than room temperature rates. Our measurement of the resonance position indicates a resonance energy of $0.42\pm 0.04$ eV for the F=1 peak in ortho deuterium.

4.

Assuming the theoretical [$(d\mu t)$dee] energy spectrum, our results for the resonant energy imply sensitivity to the binding energy of the loosely bound J=1, v=1 state of the $d\mu t$ molecule, with an accuracy approaching the magnitude of the relativistic and QED corrections, providing potential future opportunities to directly test quantum few body calculations.

5.

Indications of solid state effects have been observed in the layer thickness dependence of the fusion yield, but more theoretical input is needed for better understanding. Efforts have begun by theorists to calculate $\mu t$ interactions in solid hydrogen. The data obtained here will confront any future calculations.