A thin-lens beta-ray spectrometer is described and a brief analysis of its operation is given. A coincidence Geiger-Mueller counter to be used with this instrument is also described. The spectrometer has been calibrated with a line of the thorium B spectrum, and used to obtain beta-ray spectra of radium E and antimony 124. The experimental spectra have been found to agree well with those previously published. Several methods of plotting beta-ray spectra are described and applied to radium E and antimony 124. From the Fermi plot the endpoint of the radium E spectrum appears to be at 1.18 Mev, from the van der Held plot at 1.16 Mev. For antimony 124 four endpoints have been determined from the Fermi plot at .50, .65, .90 and 2.43 Mev. It is shown that the van der Held plot reduces to the Fermi plot for this spectrum. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Multivariate methods have been developed to assist in the interpretation of multiwavelength spectral data. When carrying out an elemental analysis by optical emission spectrometry, the analyst is faced with a choice of many spectral lines on which to base the analysis. The problem of choosing a suitable line depends upon other components in the sample, as some of these lines may suffer from spectral interferences, depending upon the nature of the sample matrix. The selection of the most suitable line for the determination of a desired component is conventionally accomplished by consulting tables of spectral emissions, and selecting a line on the basis of freedom from spectral overlap, taking into consideration the bandwidth of the spectrometer. Unfortunately, many weaker lines are not tabulated, although they may nevertheless interfere if the interfering element is at a high enough concentration. As well, emissions from sample-specific species, such as molecular species, will not be tabulated. As the possibility that a spectral line will cause a significant interference depends upon interferent concentration, the analyst has previously required detailed knowledge of the nature of other components in a sample. The methods developed in this thesis facilitate the determination of a desired component in binary, ternary, or more complex mixtures without prior knowledge of the nature of any interfering components. This automatic line selection allows the matrix-dependent tailoring of the lines chosen to the element or elements of interest. Factor analysis determines those wavelengths where an unidentified interferent contributes to the measured intensity. A multivariate analysis based on selected wavelengths gives the concentrations of all desired components while avoiding error in these concentrations due to interferents. Using a related method, the best analytical line for the determination of a specified analyte is selected from a set of lines on the basis of the least interference in a particular sample matrix, by several cycles of mathematical analysis. Unsuitable lines are rejected in the first few cycles, the best lines being retained until last. A multivariate analysis after each cycle provides an updated estimate of the analyte concentration. As with other methods in this thesis, this process is performed without reference to spectral tables. Application of these methods to a recently developed high resolution photodiode array based polychromator system is also discussed. This has consequences for the design and selection of spectral masks to assist in multielement analysis on this spectrometer. In the course of development of these multivariate methods, the need for improved dynamic range in the photodiode array was seen. An algorithm for the generation of dynamic range enhanced photodiode array spectra has been developed and implemented. / Science, Faculty of / Chemistry, Department of / Graduate

A variation of the classical canal ray source has been developed for the study of the Stark Effect in positive ion lines. Stress was placed on the measurement of small line shifts rather than the attainment of large electric fields. To this end a sensitive shift measuring apparatus employing a linear neutral density filter to translate the line shift into a change in intensity was built. Shifts were measured to an accuracy of about .02 A° in the following lines: He I 5016 A°, 7281 A°, 6678 A°, 3889 A° and Ar I 4272 A°, 4266 A°. No shifts were detected in Ar II 4727 A° and 4806 A°. A discussion of prospective improvements to be made in the apparatus is also included. With these improvements, the apparatus should be capable of measuring shifts to an accuracy of .001 A°. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

An infrared Fourier spectrophotometer has "been set up in the solid state laboratory of the University of British Columbia. A cryostat has been built and adapted to the spectrometer. A computer program to analyze the data and plot the spectrum has been written. As a demonstration of the system's capability, the transmission spectrum from 40 cmˉ¹ to 330 cmˉ¹ of boron doped silicon was obtained for the sample at liquid helium temperature. This spectrum was compared to earlier work done by Colbow in the region 240 cmˉ¹ to 330 cmˉ¹. A spectrum of boron and indium doped silicon was Investigated in the hope of finding Bˉ and In⁺ ionized centres. These were not found at the impurity concentrations and temperatures used. A transmission spectrum of intrinsic silicon at liquid helium temperature was obtained for the region 40 cmˉ¹ to 330 cmˉ¹ A comparison of the above spectra suggests that the low energy tail of the boron doped and boron and indium doped samples is due to a frequency dependent value of reflectivity as Is seen from the spectrum for intrinsic silicon. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

The fundamental vibrations of carbazole have been assigned from polarized infrared, Raman and fluorescence spectra. A crude normal coordinate calculation using a force field transferred from phenanthrene for the in-plane problem, and from benzene and anthracene for the out-of-plane problem gave satisfactory agreement with the observed frequencies. From a study of the polarized absorption spectrum of carbazole in a single crystal matrix of fluorene at about 15°K, the lowest-energy transition is assigned ¹A₁←¹A₁, and the excited state vibrations are analysed. In fluorene, an impurity with a weak absorption at 3200 Å, which previous workers inadvertently attributed to fluorene itself, was characterized as benz[f] indan. From the polarized absorption and fluorescence spectra, the transition is assigned ¹A₁←¹A₁ and vibrational analyses of these spectra are given. From a study of the absorption spectrum of a-fluorene crystal (ab face), the solution absorption spectrum is given the following interpretation: the 3000 Å system of medium intensity and the stronger 2600 Å system are long-axis polarized, and a rather weak band at 2730 Å is short-axis polarized. Vibrational analyses of the absorption and fluorescence spectra in a polycrystalline n-heptane matrix at about 15°K are presented. A vibrational analysis of the intense blue phosphorescence induced in fluorene by the deliberate addition of dibenzothiophene at about 6°K shows that the intervals are identical with those in the fluorescence and phosphorescence of fluorene in n-heptane. An assignment of the fundamentals of fluorene from polarized infrared and Raman spectra is reported. Polarized infrared and Raman spectra of dibenzothiophene-h₈ and -d₈. are utilized in an assignment of their fundamental vibrations. The in-plane frequencies were calculated using the force field transferred from phenan-threne. The lowest-energy transition of dibenzothiophene in fluorene at about 15°K is assigned ¹A₁←¹A₁. Vibrational analyses of the absorption spectrum in n-heptane and of the fluorescence and phosphorescence spectra in the crystal, n-heptane, and hexamethylbenzene are presented. An intense blue phosphorescence observed at 6°K in a biphenyl crystal following the deliberate addition of either carbazole or dibenzothiophene was identified as biphenyl phosphorescence originating from energy trapping centers created in the crystal lattice. The triplet band energy of biphenyl estimated from preliminary temperature dependence studies of the phosphorescence and delayed fluorescence agrees satisfactorily with Hirota's independent measurement. / Science, Faculty of / Chemistry, Department of / Graduate

The physiological literature on Nitrobacter is reviewed and a list of the unsolved problems presented. Modifications to the action spectrum apparatus built by Brooks (1967) are described. The apparatus was then used with Nitrobacter agilis, ATCC no. 14123, to obtain an action spectrum of the relief of carbon monoxide inhibition by light. The results of this study indicate that cytochrome a₁ is active as a terminal oxidase. The possibility of other cytochromes, principally cytochrome ₀, acting as oxidases has not been proven or ruled out. The results of a study on the rate of oxygen uptake versus oxygen concentration are also reported; the Km(0₂) values range from 0.021 to 0.055 mM oxygen. The action spectrum reported here is the. first one to be determined on a chemolithotropic bacterium. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

The spark spectra of zinc have been photographed in the region λ350 Å to λ8000 Å using a three metre normal incidence vacuum grating spectrograph, a twenty-one foot Eagle-Paschen " in-plane" grating spectrograph, and a Hilger E478 large automatic prism spectrograph with interchangeable glass or quartz optical trains. The spectra were excited using a condensed spark in helium source, a hollow cathode discharge, and a condensed electrodeless discharge source. In all, 5982 spectral lines were measured. Sixty-four line classifications were made in Zn I from previously established energy levels. Three hundred and seventy-one line classifications were made in Zn II, and 33 new levels were established. In Zn III, major revisions and extensions have led to a total of 1259 line classifications and 264 energy levels were established, 44 of which had been determined previously. Revisions to a previous report on the spectrum of Zn IV have resulted in an increase of the number of classified lines to 329. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

The static field induced absorption spectrum of hydrogen has been investigated at high resolution and with reliable frequency calibration over the density range from 1.5 amagat to 28 amagat. Frequencies have been extrapolated to zero density in order to obtain molecular constants for the isolated molecule. Line profiles have been compared with various functions and the simple dispersion profile seems to fit the data best over the density range studied. The linewidth, however, decreases with density until it reaches a minimum at about 2.5 amagat below which it starts to increase again. The minimum width is about 4 times less than the width of the classical doppler line. This behavior of the line width is consistent with the phenomena of "collision narrowing" in the infrared. From the intensities of the lines we obtain the isotropic polarizability (α )₁₋₀ = 1.21 cm³. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

The design and construction of a high-resolution, low-energy and variable-angle electron impact spectrometer has enabled the study of the interaction between a low energy monochromatic electron beam and a series of atoms and molecules. Optically forbidden transitions have been studied for argon and neon. The Rydberg transitions in atoms and small molecules have also been investigated. The "vacuum ultraviolet spectra" (electron impact spectra) obtained for some organic molecules such as the alkyl derivatives of water and carbonyl compounds have been interpreted in terms of Rydberg transitions. Substituent effects on Rydberg orbital energies and ionization potentials are discussed using Taft σ* values. / Science, Faculty of / Chemistry, Department of / Graduate

Binary (e,2e) spectroscopy is an intermediate energy electron scattering coincidence technique measuring the binding energy and spherically-averaged momentum distributions of individual valence electrons in small gaseous molecules. Momentum space chemistry is a term used to refer to the study of the attributes of molecular orbitals in the momentum space representation, rather than the usual position space representation. The relation between the two spaces is the Fourier Transform. This thesis discusses experimental measurements and theoretical calculation of the binding energy spectra and/or momentum distributions of. H₂S, COS, C0₂, NO and 0₂ in detail. It also attempts to bring into the ken of ordinary chemistry concepts and principles for dealing with momentum-space molecular orbital density functions, which are essential to the understanding of the nature of momentum distributions. In order to illustrate this, specific examples of theoretical momentum and charge density maps for several molecules are discussed. Significant new understanding of the electronic structure of these molecules is attained. The design, construction, and preliminary testing of a new binary (e,2e) spectrometer incorporating a multi-channel plate detector for improved data collection efficiency is presented. Finally, some propositions for future directions of study are put forward. / Science, Faculty of / Chemistry, Department of / Graduate