An accurately colliraated monenergetic fast neutron beam of small angular width was produced by bombarding a deuterium target with 2 MeV deuterons. Background reduction was achieved by using the associated particle technique and extensive shielding. Dual parameter pulse height analysis was used to reduce the coincidence time resolution between the detected neutrons and the associated He³ recoil particle to 4.6 nanoseconds by taking into account the variations in flight times of the He³ particles. A rotating thin film deuterated polyethylene target was developed which enabled a substantial increase in the neutron flux to be made. The beam of 70 neutrons/second/millisteradian produced, was of sufficient intensity to perform a small angle scattering experiment. The technique was tested by a measurement of the angular distribution from 40 degrees to 10 degrees of neutrons elastically scattered from lead. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

In this thesis, various fermion-boson strong interaction potentials are determined as functions of the basic fermion-boson trilinear vertex function. Working in Fock space, we note that the fermion-boson trilinear interaction does not explicitly involve physical particles. We develop a transformation, called the dressing transformation, which acts on the fundamental particle creators and annihilators. They are transformed into physical particle operators, and the invariance properties and commutation relations of the theory are preserved. A precise technique for perturbatively determining the dressing transformation is formulated, and is applied to some simple models in field theory. The dressing transformation makes explicit the physical particle interactions implicit in the original trilinear interaction. When applied to the nucleon-pion trilinear interaction, we find a nucleon mass renormalization, a nucleon-pion scattering term, and a nucleon-nucleon scattering term present in the second-order dressed Hamiltonian. Using the NN7C vertex function derived from the Cloudy Bag Model, the nucleon-nucleon coordinate space potential can be calculated. We discover that providing the two nucleons are separated by a distance greater than twice the bag radius, the potential between them is given by the one pion exchange potential modified in strength by a function of the bag radius. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

In this study the excitation function for the ^7Li(d,p)^8Li reaction is determined at incident deuteron energies ranging from 0.623MeV to 1.968MeV by counting the delayed alpha-particles as a result of the ^8Li beta decay. This excitation function reveals resonances at 0.777±0.012MeV and 1.031±0.015MeV with cross sections of 202±9mb and 188±8mb respectively. The uncertainty in the cross section values was due to three independent sources of error within this experiment, the solid angle, the ^8Li half-life, and the target (LiF) thickness. The uncertainty in the energy values was determined from an energy calibration of the accelerator used in this study. Resonances from the ^71i(p,n)^7Be (1.882MeV), 7Li(d,p)^8Li (0.770MeV; 1.02MeV) and ^19F(p,αγ)^16 0 reactions were used in this energy calibration.

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