This thesis presents the theoretical modelling and commissioning of the laser station at the newly constructed IGISOL 4 facility. The experimental techniques and apparatus of the facility, focusing on a line dedicated to laser spectroscopy, are described, followed by details on simulations of the beam-line. First spectroscopic data has been acquired at IGISOL 4. The isotope shifts and hyperfine structure of stable and radioactive molybdenum isotopes were acquired using collinear laser spectroscopy. The spectroscopy of this element was chosen in order to compare the results with those previously acquired at IGISOL 3. The isotope shifts and hyperfine dipole constants calculated were found to agree and the hyperfine structure of the 4d4(5D)5s 6D1/2 to 4d4(5D)5p 6F1/2 transition in 107Mo has been observed for the first time. A new electrostatic ion trap (ConeTrap) has been designed for trapping and optical pumping of ions in high vacuum using realistic ion optical simulations. The ConeTrap has been designed with an extended central section in order to facilitate the optical pumping of contained ions. The trap uses asymmetric voltages to achieve greater extraction efficiency and an acceptance time of ~10 us. Fast high-voltage switching circuitry has been created, with fall and rise times of <240 ns and <700 ns respectively, for dynamic trapping of ion bunches. The IGISOL ConeTrap has been designed and built for axial and radial optical pumping, however several other possible applications are also presented. These applications, to be deployed at the IGISOL 4, include using the ConeTrap as a potential energy elevator, a "high-density'' ConeTrap for two-photon spectroscopy, a "dual-stability'' ConeTrap that can provide pure, doubly-ionised bunches, a ConeTrap designed for radiation detection for spectroscopy and lifetime measurements and a combination of the ConeTrap and the current IGISOL light collection region for collinear laser spectroscopy of trapped ions.

No description available.

In this study a unique pulse amplifier, with automatic controlled gain, was used to measure nuclear lifetimes. The significance of this circuit is that it reduces the spread in pulse amplitudes of those pulses selected by Ge(Li) and NaI(Tl) detectors from a single channel analyzer. In the first part of this study a coincidence circuit composed of an Ortec module with Ge(Li) and NaI(Tl) detectors was utilized. The coincidence curves of two different sources, 22Na (0.511 MeV from positron annihilation) and 133Ba (0.081-MeV excited state), were recorded by a multichannel analyzer. In the second part of this research the unique pulse amplifier was added to the original coincidence circuit. The coincidence curve of the two sources was again recorded, and comparison of the two methods was made. A twenty five percent improvement in time resolution for 22Na and a twenty percent improvement for 133Na was achieved.Ball State UniversityMuncie, IN 47306

Thesis--Utrecht. / Foreword in Dutch; summary in Dutch and English. Curriculum vitae (In Dutch). Includes bibliographical references.

Thesis--Utrecht. / Foreword in Dutch; summary in Dutch and English. Curriculum vitae (In Dutch). Includes bibliographical references.

Philosophiae Doctor - PhD / The progressive development of scintillator detectors has made it possible to perform direct electronic lifetime determination up to a few hundred nanoseconds. The 2" by 2" LaBr3:Ce detectors provide a combination of excellent time resolution and good energy resolution. Recently a fast timing array has been commissioned at iThemba LABS, Cape Town consisting of eight 2" by 2" LaBr3:Ce detectors. Test measurements using radioactive sources produced at the laboratory were conducted. Six 2" by 2" LaBr3:Ce detectors were coupled to the AFRODITE array as their rst in-beam experiment. AFRODITE consisted of eight HPGe clover detectors as well as two 3.5" x 8" LaBr3:Ce detectors. A particle telescope was used to select the desired reaction channels. The reactions of interest 45Sc(p,d)44Sc and 45Sc(p, )42Ca were carried out at a beam energy of 27 MeV. The current analysis also investigates the rare earth nucleus 150Gd which was populated through 150Sm( ,4n)150Gd at a beam energy of 48 MeV.

No description available.

A miniaturized super-regenerative nuclear quadrupole resonance spectrometer was fabricated in this project. The spectrometer was constructed using thin-film chromium resistors, gold-nickel conductors, and field effect transistors. The unit operated at room temperature and at 77º K between the frequencies of 24.860 and 44.300 MHs.The spectrometer was fabricated on a ceramic substrate which was 5.08 x 5.08cm. The films consisted of vacuum deposited chromium, electroless plated nickel, and electroplated gold. The resistor-conductor pattern was photo-etched from the films and the remaining components attached to the films to form the circuit.The spectrometer was encased in a stainless steel belljar with the sample coil extending from the bottom and the signal and power leads extending from the top of the belljar. The unit was immersed in liquid nitrogen and the characteristics monitored as the temperature dropped.The spectrometer operated in the liquid nitrogen, but failed to yield a signal for a paradichlorobenzene sample. The spectrometer exhibited poor frequency selectivity and a frequency change of 2MHz (6%) in going from room temperature to liquid nitrogen (77º K).Ball State UniversityMuncie, IN 47306

This thesis includes elementary introductions to nuclear quadrupole resonance (NQR) detection and fieldeffect transistors (PET). The construction and operation of the FET-NQR detector, as originally designed by Viswanathan, Viswanathan and Sane and published in Rev. Sci. Instr. 39,472 (1968), is discussed extensively. The thesis also contains a step by step discussion of the construction of an alternate PET-N'QP detector. Although the alternate detector never functioned properly, the information gathered would aid anyone desiring to design and construct a new NQR detector.Ball State UniversityMuncie, IN 47306

No description available.