Several new techniques for improving the statistics of counting small peaks on large backgrounds in a beta-spectrometer are presented. These arose from an attempt to reconcile the conflicting reports in the literature of gamma-transitions in Ra (B + C) above 1.02 Mev. Some success has been met with. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

The angular distribution of the gamma-rays from the direct radiative capture reaction D(p,ɣ)³He has been measured for 70 KeV and 144 KeV protons in the laboratory system, using thin deuterated polyethylene targets. The study of this particularly simple reaction is of interest for determining some properties of the forces which bind nuclear particles to each other. In addition it plays a role in a number of astrophysical processes. The ground state of ³He is predominantly a symmetric ²S state with admixtures of a ⁴D state and ²S(m) state of mixed symmetry. These admixtues are related to specific components of the two body forces coupling the three particles. The measurements were made with a high current 180 KeV accelerator, built by the author, using an ORTEC duoplasmatron ion source. Technical problems involved in the development of the accelerator and the deuterated targets are discussed. The angular distribution at 144 ± 16 KeV in terms of Legendre polynomials P₁ is given in the centre of mass system by W(ɵ) = Aₒ[Pₒ+(.05±.02)P₁-(.94±.02)P₂-(.05±.02)P₃+(.03±.02)P₄] and at 70 ± 20 KeV the angular distribution is given by W(ɵ) = Aₒ[Pₒ+(.(.06±.04)P₁-(.93±.05)P₂-(.06i±.04)P₃+(.02±.05)P₄] The coefficients in the Legendre polynomial expansion are related to the various transitions between the continuum and bound states. Their significance in terms of the different components of the ³He ground state wave function is discussed. The absolute cross section (i.e. the coefficient Aₒ ) has not been measured. Plans for measuring it in the near future are discussed briefly. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Several high quality electronic units were previously acquired on an individual basis from various manufacturers. As the second research effort in a planned complementary series of papers, the capability of the total array of equipment to accomplish reliable measurements of nuclear radiation was established.To evaluate the performance of the electronic units when assembled into a working coincidence system with associated test and analysis units, positron emitter, was employed with a copper converter as the source of annihilation gamma rays. The annihilation pair gamma-ray energies was precisely 0.511 MeV and the rays were emitted in opposite directions simultaneously. With a range of results that must be attained known, the equipment was arranged, meticulously calibrated and many coincidence counts completed under widely varied conditions. Resolving time and angular resolution were used as the standards for evaluation of the equipment capability. The resolving time was 29.5 nanoseconds while the angular resolution was 14 degrees. These values indicate a very good capability to proceed with many varieties of nuclear radiation research.

The purpose of this investigation was to provide a method for determining the relative intensities of all gamma rays in a particular spectrum, and thereby determine the relative transition probabilities.

No description available.

Proefschrift--Utrecht. / Summary in Dutch. Bibliography: p. 77-79.

Thesis--Ph. D., University of Hong Kong, 1983.

Thesis (M.A.)--Kutztown State College, 1974. / Source: Masters Abstracts International, Volume: 45-06, page: 3057. Typescript. Abstract precedes thesis as preliminary leaves [1] Includes bibliographical references (leaf 20).

published_or_final_version / Physics / Master / Master of Philosophy

published_or_final_version / Physics / Doctoral / Doctor of Philosophy