Thesis (M.S.)--Mississippi State University. Department of Electrical and Computer Engineering. / Title from title screen. Includes bibliographical references.

Thesis (M.S.) University of Missouri-Columbia, 2005. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (July 10, 2006) Includes bibliographical references.

The multi-order response of the tuned secondary circuit of a Tesla transformer, following impulse excitation from its tuned primary circuit, is presented and analysed at the fundamental resonant frequency and at higher-order mode frequencies. A novel way of modifying the frequency response of the secondary coil is then investigated by utilising a technique normally applied to the design of a certain type of filter known as a helical filter. In general, these are used in radio and microwave frequency circuits in order to pass certain frequencies with little attenuation whilst significantly attenuating other frequencies. Design techniques, developed over several decades, modify and optimise the performance of such filters. The frequency response of the helical filter is modified by altering the geometry of the helical resonator component therein, which is typically in the form of an air-cored single-layer solenoid. A Tesla transformer whose secondary is constructed to be some form of single-layer solenoidal winding resonates at its designed frequency - its fundamental mode - but also at non-integer harmonics (higher-order anharmonic frequencies, also known as overtones). Those multi-order oscillatory voltages and currents energised in the secondary circuit have been identified and measured and research has determined the fundamental and higher-order mode frequencies and amplitudes for various experimental secondary winding configurations derived from helical filter design techniques. Applied to the Tesla transformer secondary winding, such techniques lead to a new design with a performance that is improved by the suppression of higher- order anharmonic frequencies whilst imparting little change to the fundamental response. It is anticipated that this feature will lead to Tesla transformers which exhibit enhanced spectral purity and which will be better suited to use in certain pulsed power applications than conventionally wound designs.

The plasma opening switch (POS) is used in pulsed power systems where a very fast opening and high current switch is required. Plasma is injected into the switch, which carries a large conduction current, before it opens in a process that lasts for a few nanosecond and transfers the current to a parallel-connected load at a much increased voltage and with a much shorter rise time. The conduction and opening times of the switch are dependent on plasma parameters such as the distribution, speed and species, all of which are determined by the plasma source. Most of the earlier reported work involves large dimension POSs and a correspondingly high input current (more than 100 kA) and uses carbon plasma. One main objective of the present research was to achieve a low input current (20 kA) and miniaturised POS by using hydrogen plasma rather than carbon plasma on account of its lower mass. A cable gun was selected for producing the plasma, since although this produces both hydrogen and carbon plasma these arise different times during its operation. For the present application a Tesla transformer was used in preference to a Marx generator to produce an initial high voltage pulse for the system, on the basis of its simpler design and cost effectiveness. This transformer together with an associated water PFL (pulse forming line) and pressurised switch was capable of producing a load current in excess of 20 kA with a rise time of 53 ns, which was fed through the POS to the final load. Special diagnostics arrangements were necessary to measure the fast high current and voltage pulse a in nonintrusive way. Faraday cups and a high speed camera were used to measure the plasma parameters. The overall system built (i.e. including the POS) is capable of producing a 22 kA current with a rise time of 5 ns, and of generating a power of more than 10 GW. Much of the work detailed in the thesis has already been presented in peer reviewed journals and at prestigious international conferences.

Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, September 2003. / Thesis advisor(s): Robert W. Ashton, William B. Maier II. Includes bibliographical references (p. 83-84). Also available online.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: PPT; pulsed plasma thruster; Langmuir probe; plasma diagnostics; electric propulsion; electron temperature; electron density. Includes bibliographical references (p. 97-102).

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on October 5, 2009). Thesis advisor: Dr. Scott Kovaleski. Includes bibliographical references.

Thesis (M.S.) -- Worcester Polytechnic Institute. / Keywords: electric propulsion; applied magnetic fields; pulsed plasma thruster. Includes bibliographical references (p. 91-94).

A Tesla-Blumlein PFL-Bipolar pulsed power generator, has been successfully designed, manufactured and demonstrated. The compact Tesla transformer that it employs has successfully charged capacitive loads to peak voltages up to 0.6 MV with an overall energy efficiency in excess of 90%. The Tesla driven Blumlein PFL generator is capable of producing a voltage impulse approaching 0.6 MV with a rise time close to 2 ns, generating a peak electrical power of up to 10 GW for 5 ns when connected to a 30 Ω resistive load. Potentially for medical application, a bipolar former has been designed and successfully implemented as an extension to the system and to enable the generation of a sinusoid-like voltage impulse with a peak-to-peak value reaching 650 kV and having a frequency bandwidth beyond 1 GHz. This thesis describes the application of various numerical techniques used to design a successful generator, such as filamentary modelling, electrostatic and transient (PSpice) circuit analysis, and Computer Simulation Technology (CST) simulation. All the major parameters of both the Tesla transformer, the Blumlein pulse forming line and the bipolar former were determined, enabling accurate modelling of the overall unit to be performed. The wide bandwidth and ultrafast embedded sensors used to monitor the dynamic characteristics of the overall system are also presented. Experimental results obtained during this major experimental programme are compared with theoretical predictions and the way ahead towards connecting to an antenna for medical application is considered.

A dense plasma focus device (DPF) is a pulsed power device that generates high energy particles, neutrons and X-rays through rapid compression of the plasma. The presented research investigates the modification of the DPF and use of numerical modelling to predict the neutron yield. The DPF is a 1 kJ device that uses a 1.3 uF capacitor and operated at 40 kV pulse. Spark gap switch SG181-C is integrated into the driver circuit to handle high current operations. Bus work is designed and modeled to predict the current waveform generated by the modified DPF. The control system is designed to be suitable for automation using DAQ and LabVIEW. Radial trajectories during pinch formation are analyzed using a numerical model. Two numerical models are used to investigate how neutron yield varies with pressure, pinch current and pinch duration. The modified DPF showed the neutron scaling to be fourth power of the pinch current. / Master of Science / Nuclear fusion has been researched widely for decades as a solution to meet the demand of increasing energy needs. Controlled fusion reactions has been the main challenge to achieve this and various approaches have been explored using different confinement methods. All the approaches have advantages with different challenges. One approach being explored is the dense plasma focus (DPF) device, which uses electrical discharges to create a dense 'pinch' of plasma where fusion reactions occur when operated in deuterium fuel gas. Recent DPF experiments have shown that kJ range devices are capable of generating neutrons and intense radiation. This research gives an overview of the DPF with energy of 1 kJ range. The DPF is modelled to predict the pinch formation parameters. The model also predicts how neutron yield varies with operating pressure, pinch current and duration.