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Cross Sections were measured with uncertainties of 13 to 21 % for the reactions.

An eleven-year series of radio timing observations of 0833- 45 (Vela) and PSR 1641- 45 is presented. During this time, five large spin-ups ("glitches") were observed in 0833- 45 and one in 1641-45. The stellar response to these events is investigated, and the three relat ively long complete inter-glitch intervals in 0833-45 are modeled. The results are of relevance to studies of the interiors of neutron stars. The initial aim of the project - to obtain good observational coverage of large glitches in the Vela pulsar - was successfully achieved, and high quality observations of the periods between glitches were obtained as a by-product. The results of the analysis presented here provide support for the existence of both linear and non-linear coupling in the Vela pulsar, and put a limit on the former in PSR 1641- 45. The recently observed existence of a rapidly recovering component of part of a glitch in Vela was verified in the subsequent glitch, although there is now evidence to contradict the suggestion that this component involves a particular region of the star that is implicated in every glitch. Observations of a recent glitch in the same pulsar have resolved a small component of the spin-up; such a component has not been reported for any other large glitch.

This thesis is aimed at the study of high angular momentum states in neutron deficient nuclei in the mass 60 region, with approximately equal numbers of protons and neutrons, (N~Z). The main motivations of this work are to provide an insight into the mechanisms for generation of high angular momentum states in a limited particle valence space above the N=Z=28 doubly magic core, and to investigate the role of the isospin quantum number in heavy N=Z nuclei. The decay scheme for the odd-odd N=Z nucleus 6231Ga has been deduced for the first time, and the decay schemes for 61Zn and 61Cu have been extended. The data came from two experiments, the first using the reaction 24Mg + 40Ca at a beam energy of 65 MeV, performed at the Argonne National Laboratory, Chicago, US, using the germanium gamma-ray detector array 'AYEBALL' in conjunction with the Argonne Fragment Mass Analyzer and a gas filled ionisation chamber. The second experiment using the reaction 28Si + 40Ca at a beam energy of 88 MeV was performed at the Niels Bohr Institute, Riso, Copenhagen, Denmark using the 'PEX' gamma-ray detector array with a charged particle detector ball and an array of liquid scintillator neutron detectors. The data analysis techniques and results of the experimental analysis are presented. Gamma-ray energy spectra for different nuclei are shown according to the mass, neutron number and proton number of the nucleus. The proposed decay schemes are justified by coincidence and DCO arguments, and are compared to shell model calculations using a restricted pf5/2 g9/2basis. In the case of 62Ga, these are then compared with the latest IBM-4 calculation, which explicitly includes T=0 and T=1 bosons. Suggestions are also made for future work to complement this data.

The intent of this investigation is the determination of the values of the Cs-133 (n,2n)Cs-132 cross-section at neutron energies of 15.6 and 16.1 MeV. Neutrons of this energy are produced with comparative ease by means of the D-T reaction, in which deuterons of energy 500 and 750 keV, respectively, are impingent upon a tritium target.

No description available.

In this thesis, a review of the most prominent pulsar glitch mechanisms is presented. This includes a discussion of the internal structure of neutron stars and the way in which glitches may be used to describe that structure. Particular attention is paid to the two-component model. This thesis also includes numerous simulations of the two-component model, which are fitted to observational data in order to determine how suitable this mechanism is as a description of pulsar glitches. The results show that this mechanism is in fact still relevant, in spite of its age. / Dr. C.A. Engelbrecht Dr. F.A.M. Frescura

No description available.

This thesis explores gamma rays from neutron excitation of Cs133.