In this thesis, we have reported a new approach in CF studies, * viz* the time-of-flight method using an atomic beam of muonic
tritium. With this new technique we have made measurements on scattering as well as epithermal
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 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 CF processes with detailed expressions for scattered 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
energy was obtained, enabling us to
spectroscopically establish the existence of the Ramsauer-Townsend effect
in
interactions. The energy of the RT minimum was measured to
be
eV, in fair agreement with quantum three body calculations
by Chiccoli
*et al.*[17]. - 2.
- Using the
beam, we have confirmed theoretical scattering cross sections [17] to the 10% level by measuring the
attenuation of
through deuterium. Comparisons with Monte Carlo
simulations, assuming different scattering angular distributions, also
confirmed the importance of
-wave scattering in the interaction, giving angular momentum information on the loosely bound state of the molecule.*p* - 3.
- The existence of the predicted large resonance in
collisions
was directly confirmed for the first time. Our results of the resonance
strength correspond to a peak rate of
s
when 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 eV for the^{-1}peak in ortho deuterium.*F*=1 - 4.
- Assuming the theoretical [dee] energy spectrum, our results for
the resonant energy imply sensitivity to the binding energy of the loosely
bound
state of the molecule, with an accuracy approaching the magnitude of the relativistic and QED corrections, providing potential future opportunities to directly test quantum few body calculations.*J*=1,*v*=1 - 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 interactions in solid hydrogen. The data obtained here will confront any future calculations.