New Zealand has a paradoxical relationship with nuclear science. We are as proud of Ernest Rutherford, known as the father of nuclear science, as of our nuclear-free status. Early enthusiasm for radium and X-rays in the first half of the twentieth century and euphoria in the 1950s about the discovery of uranium in a West Coast road cutting was countered by outrage at French nuclear testing in the Pacific and protests against visits from American nuclear-powered warships. New Zealand today has a strong nuclear-free identity – a result of the New Zealand Nuclear Free Zone, Disarmament and Arms Control Act of 1987 that prohibited nuclear weapons and nuclear warships in the country’s land, air and water – that can be traced back to the first protests against nuclear weapons in the 1940s. This thesis is based on the supposition that the “nuclear-free New Zealand” narrative is so strong and such a part of the national identity that it has largely eclipsed another story, the pre-1980s story of “nuclear New Zealand”. New Zealand’s early embracing of and enthusiasm for nuclear science and technology needs to be introduced into our national story. This thesis aims to discover and reveal that history: from the young New Zealand physicists seconded to work on the Manhattan Project; to the plans for a heavy water plant at Wairakei; prospecting for uranium on the West Coast of the South Island; plans for a nuclear power station on the Kaipara Harbour; and the thousands of scientists and medical professionals who have worked with nuclear technology. Put together, they provide a narrative history of nuclear New Zealand. Between the “anti-nuclear” voices, already well told in many histories of nuclear-free New Zealand, and the “pro-nuclear” voices revealed in this thesis, options were considered and decisions made. This thesis shows that the people with decision-making power tended to make practical decisions based on economics and national interest when it came to deciding whether or not to adopt a certain piece of nuclear technology or whether or not to participate in projects or ventures with international agencies. This eventually led to a nuclear-free policy – focused on weapons, nuclear-powered ships and waste – that since the legislation was enacted in 1987 has been interpreted ever more widely by politicians and the public to include nuclear power, uranium prospecting and many other applications of nuclear technology.

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The phosphine(III) crown ethers, [4'-(N-phenylaza-15crown-5)]3P (1), [4'-(N-phenylaza-l8-crown-6)]3P (2), [4'-(Naza-18-crown-6)]2-Ph-P (3), and [4'-(benzo-15-crown-5)]3P (4) were synthesized by using an electrophilic bromination of the crown phenyl ring (with a tribromide ion) followed by the preparation of a lithium salt and subsequent reaction of the resulting lithiocrowns with P(III) reagents. The oxide of compound 1 was completely characterized by an X-ray diffraction study, which showed that structurally there is not a significant difference in P-O bond distances and OPC bond angles with [4'-(N-phenylaza-15-crown-5)]-Ph2-P=O. Thespectroscopic data of compound 1 and 2 were compared. It appears that 1 and 2 are similar in P environment; also they are more air sensitive than 3 and 4. In addition, a discussion about compounds 1-4, and a literature review of the preparation of phosphines are included. / Department of Chemistry

Supernova explosions are among the most energetic events known in the universe, leaving supernova remnants (SNRs) as their relics. The cores of massive stars collapse to form neutron stars, among the most compact and strongest magnets in the cosmos. The thesis studies a sample of such magnetic "beauties" in X-rays, the magnetars and high-magnetic field pulsars (HBPs), with the motivation to understand their evolutionary links. We also address the connection between these sources by investigating their environs through their securely associated SNRs. Magnetars have ultra-high magnetic fields B ~ 10^{14} - 10^{15} Gauss (G) and include the soft-gamma repeaters (SGRs) and anomalous X-ray pulsars (AXPs). The HBPs have magnetic fields B ~ 10^{13} - 10^{14} G, intermediate between the classical rotation-powered pulsars (B ~ 10^{12} G) and magnetars. We focussed on two HBPs: J1119-6127 and J1846-0258, with similar spin-properties and associated with the SNRs G292.2-0.5 and Kes 75, respectively. In our studies, magnetar-like behavior was discovered from the Crab-like pulsar J1846-0258, clearly establishing a connection between the HBPs and magnetars for the first time, while no such behavior has been observed from PSR J1119-6127 so far. J1119-6127's overall X-ray properties together with its compact pulsar wind nebula resemble more the classical rotation-powered pulsars. We studied two magnetars, one from each sub-class: SGR 0501+4516 and AXP 1E 1841-045. The spectral and statistical analysis of the bursts and the persistent X-ray emission properties observed from them were found consistent with the magnetar model predictions as well as those seen in other SGRs. Finally, we probed the environment of these stellar magnets by performing a detailed X-ray imaging and spatially resolved spectroscopic study of two SNRs: G292.2-0.5 and Kes 73 associated with J1119-6127 and 1E 1841-045, respectively. We found that both SNRs point to very massive progenitors (>~25 solar masses), further supporting the growing evidence for magnetars originating from massive progenitors using other multiwavelength studies.

This thesis present photoluminescence spectroscopy and X-ray diffraction analyses of four different cadmium zinc telluride samples with different quality and features and similar zinc molar concentration of 10%. Photoluminescence spectroscopy of the samples let us obtain several physical parameters of the samples which are indicators of quality, composition, structure, and impurity levels of the samples. The band gap energy of the samples obtained from the photoluminescence spectra at low temperatures helped us to estimate zinc molar concentration of the samples. Temperature dependence of band gap energy in these samples has been analyzed and exciton-LO phonon interactions in the samples has been analyzed. From temperature dependence of full width at half maximum of the photoluminescence peak several parameters including concentration of impurity centers and inhomogeneity of the samples are determined and compared in order to check the quality of the samples. Thermal quenching of the photoluminescence peak has been analyzed and the processes which are associated with each parameter are determined and discussed. X-ray diffraction analyses of the sample for the location and width of the peaks have been analyzed and several characteristics of the samples including quality, lattice constant and zinc molar concentration of the samples are determined and compared. The parameters that are obtained from these analyses are compared with the ones from the photoluminescence spectra and showed a good agreement between the results of these two non-destructive characterization techniques. / Graduate / 0605 / 0544 / 0794

This thesis present photoluminescence spectroscopy and X-ray diffraction analyses of four different cadmium zinc telluride samples with different quality and features and similar zinc molar concentration of 10%. Photoluminescence spectroscopy of the samples let us obtain several physical parameters of the samples which are indicators of quality, composition, structure, and impurity levels of the samples. The band gap energy of the samples obtained from the photoluminescence spectra at low temperatures helped us to estimate zinc molar concentration of the samples. Temperature dependence of band gap energy in these samples has been analyzed and exciton-LO phonon interactions in the samples has been analyzed. From temperature dependence of full width at half maximum of the photoluminescence peak several parameters including concentration of impurity centers and inhomogeneity of the samples are determined and compared in order to check the quality of the samples. Thermal quenching of the photoluminescence peak has been analyzed and the processes which are associated with each parameter are determined and discussed. X-ray diffraction analyses of the sample for the location and width of the peaks have been analyzed and several characteristics of the samples including quality, lattice constant and zinc molar concentration of the samples are determined and compared. The parameters that are obtained from these analyses are compared with the ones from the photoluminescence spectra and showed a good agreement between the results of these two non-destructive characterization techniques. / Graduate / 0605 / 0544 / 0794

An introduction is given to the fields of X-ray and cataclysmic binaries, low mass X-ray binaries (LMXBs) and globular clusters. New observations of the W Vir star AC5 (=V86) are used show that it is probably the source of Hα emission previous authors have found in core of the globular cluster M15. The first phase resolved optical spectroscopy of AC211, the optical counterpart of the X-ray source in M15, are presented, and its binary period discovered to be 9.l±0.5 hours. A re-analysis of archive ultraviolet (UV) spectra of M15, shows spectral features which are attributed to AC211. These observations are combined with those of other authors, to prove AC211 is probably an "accretion disc corona" (ADC) source. After reviewing the superoutbursts of the SU UMa class of dwarf novae, X-ray, UV, optical and infrared observations of the SU UMa star OY Car are used to show that during superoutburst there is extensive vertical structure in its accretion disc, similar to that in the ADC and "dipping" LMXBs. Archive UV data from the 1978 outburst of WZ Sge shows that it had similar vertical structure. UV observations presented of EX Hya during a bright outburst may have the same explanation. From the OY Car data, a temperature and area for the region which produces the "superhump" light are derived, of 8 OOOK and ^-10²⁰cm², respectively. It is found that during OY Car's superoutburst, the size of the 0-C variations of the eclipse timings are significantly smaller than was previously thought, and that it has an extended X-ray source whose size is comparable to the binary separation. The results are discussed with respect to models of the superhump phenomena in SU UMa stars, and possible causes of vertical disc structure in X-ray and cataclysmic binaries.

Data from a new, wide field, coincident optical and X-ray survey, the X-ray Dark Cluster Survey (XDCS) are presented. The aim was to conduct simultaneous and independent searches for clusters of galaxies in the optical and X-ray passbands. Optical cluster detection algorithms implemented on the data are detailed. This resulted in catalogues of 185 I-band selected, 290 colour selected and 15 X-ray selected systems, residing in of optical + X-ray imaging. The relationship between optical (L(_E)) and X-ray luminosity (L(_x) ) was examined and found to exhibit significant scatter. This study highlights the higher efficiency and resolution of optical colour selection compared with other cluster detection methods. Spectroscopic redshifts confirmed the reality of a subsample of systems which were found with the optical algorithms, but required to have no detectable X-ray emission. These systems show comparable optical luminosity to the most X-ray luminous clusters, but orders of magnitude lower X-ray emission. This is consistent with the large scatter seen in the L(_x)-L(_e) relation. A near-infrared multicolour technique was explored and extended to search for high redshift (z>l) clusters. Finally, application of such techniques to forthcoming wide field near-infrared surveys was discussed and predictions for cluster finding in such surveys made.

No description available.

This thesis covers three topics related to the field of crystal engineering. Three different approaches to improving the understanding of hydrogen bonding are covered; analysis of a family of related molecules, investigations of specific functional groups and a systematic, data-driven study of intramolecular hydrogen bonding patterns. Chapters 2 to 4 and chapter 11 cover the background theory to the different methods used to obtain the data discussed in the remainder of the thesis. X-ray and neutron diffraction techniques are discussed, along with sections describing the Cambridge Structural Database, which was used as a data source throughout this work, and a brief section on intermolecular forces. Crystal structure analyses of seventeen gem-alkynol molecules are given in chapters 5 to 10. The gem-alkynol functionality is particularly interesting for a study of intermolecular interactions as it is a combination of both a strong and weak hydrogen bonding group. The group of molecules was investigated with the aim of locating robust supramolecular motifs. The group is subdivided into sections containing molecules with similar structures and their packing patterns are discussed. The second experimental section, chapters 12 and 13, comprises statistical studies into the function of the azido and cyano functional groups as hydrogen bond acceptors. The technique used was to use the Cambridge Structural Database as a data source for the main analysis, then complement the results with simple theoretical calculations. The remaining chapter, 14, describes a systematic analysis of intermolecular hydrogen bonded motifs. A data-driven approach was designed which allows direct comparison of motifs by means of a probability ordered list.