Molecular formation and destruction processes are explored in rapidly evolving, non-equilibrium astrophysical environments. First, a semi-classical calculation is made for the rate coefficients of excited atom radiative association to form molecular hydrogen and of the process C⁺ + O → CO⁺ + hν. The latter process may be important to the formation of CO in the core of Supernova 1987A. It is shown that the excited atom process may have been important to the formation of H$\sb2$ during the early part of the epoch of recombination in the early Universe. The equations of ionization balance and molecular formation and destruction have been integrated through the epoch of recombination. Other processes are examined in detail. These include heating and cooling of the primordial plasma, damping of fluctuations prior to decoupling, and the possibility of a radiation-driven instability at the onset of recombination. A calculation is presented of the time-dependent chemical evolution in the rapidly expanding outer envelope of SN 1987A. Various cooling rates and hydrogen abundances in the envelope have been examined. It is found that large molecular abundances, in particular CO, form rapidly, while hydrogen remains mostly in its atomic forms. Near-infrared observations of the proto-planetary nebula CRL 618 are presented and discussed. Images acquired in the H and K bandpasses are consistent with a bipolar axis highly inclined to the plane of the sky. From the spectrum, a visual extinction of Aᵥ = 5.3 magnitudes to the molecular hydrogen emitting lobes is found. It is shown by comparison with spectral models that the near-infrared H₂ spectrum exhibits emission from thermally excited molecules at Tₑₓ ∼ 2000 K. A component of fluorescent emission may also be present. The suggestion is explored that large molecules, in particular polycyclic aromatic hydrocarbons (PAHs), are formed in stellar winds. It is asserted that the primary source of interstellar PAHs is mass-losing asymptotic giant branch carbon stars. It is apparent that the known numbers of the most extreme mass-losing carbon stars are able to produce PAHs in sufficient quantities to maintain an interstellar medium well mixed in such molecules at the inferred abundance.

Thesis (Ph.D.)--University of Adelaide, Dept. of Physics, 1972.

Dissertation (Ph.D.)--Worcester Polytechnic Institute. / Keywords: nuclear physics, particle physics, phyiscs, resonance, nuyclear fragmentation, nucleon-nucleon interactions, radiation shileding, heavy-ion physics, space radiation. Includes bibliographical references (leaves 163-141).

Thesis (Honors)--College of William and Mary, 2009. / Includes bibliographical references (leaf 36). Also available via the World Wide Web.

Not available / text

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

No description available.

Experiments were conducted on current-mirror MOSFETs to examine their suitability for use in radiation environments. These devices, which allow low loss load current sensing (defined by a current-ratio n'), are an important element of many power integrated circuits (PICs). Total-dose testing demonstrated that the current ratio was virtually unaffected for many operating conditions. In all cases, changes were largest when sense resistance was largest and minimal when sense voltage was approximately equal to the load source's voltage. In addition, testing verified the feasibility of using sense-cell MOSFETs for applications which require radiation exposure. A constant-current op-amp circuit showed minimal current shifts, using proper circuit design, following total-dose exposure. Dose-rate testing showed the feasibility of using sense voltage to trigger g&d2; protection through drain-source voltage clamping, providing a relatively inexpensive alternative to voltage derating.

Cosmic microwave background observations have been fundamental in forming the standard model of cosmology. Ongoing and upcoming cosmic microwave background experiments aim to confirm this model and push the boundaries of our knowledge to the very first moments of the Universe. Non-cosmological microwave radiation from the Galaxy and beyond, called foregrounds, obscures and contaminates these measurements. Understanding the sources and effects of foregrounds and removing their imprint in cosmic microwave background observations is a major obstacle to making cosmological inferences. This thesis contains my work studying these foregrounds. First, I will present observations of a well-known but poorly understood foreground called anomalous microwave emission. Second, I will present results forecasting the capability of a next-generation satellite experiment to detect cosmic microwave background spectral distortions in the presence of foregrounds. Third, I will present results studying the effect of foregrounds on the cosmic microwave background self-calibration method, which allows experiments to calibrate the telescope polarization angle using the cosmic microwave background itself. Fourth, I will present my analysis characterizing the performance of and producing maps for the E and B Experiment. Fifth, I will present my research contributions to the readout system that used in the laboratory to operate kinetic inductance detectors, which are being developed for cosmic microwave background observations. Lastly, I will conclude with future prospects in the field of foregrounds and cosmic microwave background cosmology.

The effects of ionizing radiation on the breakdown-voltage degradation of power-MOSFET termination structures were examined through two-dimensional simulation. A wide variety of sensitivity to surface-charge density was found for various devices employing floating field rings and/or equipotential field plates. Termination structures that were both insensitive to surface charge and possessed a high breakdown voltage were identified. The results were compared with measurements made on selected structures. The principal ionizing radiation damaging mechanisms in MOS devices are discussed. Modifications made to an existing simulation program in order to simulate these complex field ring and field plate structures are described. Background information into how these termination structures improve the breakdown voltage and their sensitivities to positive interface charge buildup is investigated.