A cylindrical drift chamber has been designed and built at the State University of New York at Stony Brook. This chamber is to be installed in the D0 detector which is being completed at the Fermi National Accelerator. In this dissertation the design, construction and testing of this chamber are described. The characteristic features of this chamber are cells formed by solid walls and a modular structure. Much discussion is given to the performance of and results from a chamber made from three final modules which was installed in the D0 interaction region during the 1988/1989 collider run. Using this chamber proton anti-proton interactions were measured at the D0 interaction point.

Nitrogen oxides have been linked to a broad range of air pollution problems including acid rain and the atmospheric production of photochemical ozone. Over twenty million tons of nitrogen oxides are emitted into the atmosphere each year as a result of the high temperature combustion of fossil fuels. Efforts to control nitrogen oxides emissions have lagged because of the generally low discharge concentrations of nitrogen oxides in combustion exhaust and because nitrogen oxides are more difficult to remove due to their lower reactivity. No catalyst has yet been found that will achieve significant reduction of nitrogen oxides in an oxidizing environment. Oxygen in the exhaust stream competes with nitrogen oxides for the active catalyst sites. Also, the dissociated oxygen atoms produced by decomposition of nitrogen oxides deactivate the surface of the catalyst. Externally applied electric fields have been used to control oxygen adsorption on metal and semi-conductor surfaces. In this investigation, a stream containing nitric oxide has been subjected to intense electric fields in the presence of catalyst materials including steel, stainless steel, and gold plated stainless steel wools and glass wool. The electric fields have been generated using DC, AC and rectified AC potentials in the range of 0--20 …

In this thesis we study the jet production cross section in the central rapidity region in {bar p}p collisions at a center of mass energy of 1.8 TeV. The pseudo-rapidity {eta} is defined as {eta} {triple_bond} -ln(tan({theta}/2)), where {theta} is the angle between the directions of the jet momentum and the proton beam. We will call the region -0.7 < {eta} < 0.7 the 'central rapidity' region by definition. The goal of this thesis is to determine two kinds of differential cross sections for jet production: an inclusive jet Et distribution d{sigma}/dEt, and the distribution in invariant mass d{sigma}/dM{sub JJ} of two jet systems. These spectra serve to check the strong interaction theory, and thus to look for new phenomena, at the highest available energy. The strong interaction theory will be discussed.

A nuclear fuel element and a method of manufacturing the element. The fuel element is comprised of a metal primary container and a fuel pellet which is located inside it and which is often fragmented. The primary container is subjected to elevated pressure and temperature to deform the container such that the container conforms to the fuel pellet, that is, such that the container is in substantial contact with the surface of the pellet. This conformance eliminates clearances which permit rubbing together of fuel pellet fragments and rubbing of fuel pellet fragments against the container, thus reducing the amount of dust inside the fuel container and the amount of dust which may escape in the event of container breach. Also, as a result of the inventive method, fuel pellet fragments tend to adhere to one another to form a coherent non-fragmented mass: this reduces the tendency of a fragment to pierce the container in the event of impact. 1 fig., 1 tab.

The trivalent uranium compound, (MeC{sub 5}H{sub 4}){sub 3}U(thf), serves as a one- or two-electron reducing agent towards azides, RN{sub 3}. These reactions produce either the uranium(IV) azide, (MeC{sub 5}H{sub 4}){sub 3}UN{sub 3}, or uranium(V) imides, (MeC{sub 5}H{sub 4}){sub 3}UNR. The role of steric and electronic effects upon this reaction has been investigated using several series of azides. For Me{sub 3}XN{sub 3}, the imides are produced when X = C or Si, both products are formed when X = Ge, and the azide is produced when X = Sn. For Ph{sub 3}XN{sub 3}, the azide is produced when X = C or Sn. For Ph{sub 3-x}CH{sub 3}N{sub 3}, the imide is produced when x = 2 and both compounds are produced when x = 1. For substituted phenylazides, RC{sub 6}H{sub 4}N{sub 3}, only the imides are produced. The magnetic properties of uranium diimides, ((MeC{sub 5}H{sub 4}){sub 3}U){sub 2}({mu}-NRN), were investigated. Several uranium(III) amines, (MeC{sub 5}H{sub 4}){sub 3}U(NH{sub 2}R), were produced from (MeC{sub 5}H{sub 4}){sub 3}U(thf) and RNH{sub 2}, and NH{sub 3} was found to be a better ligand towards (MeC{sub 5}H{sub 4}){sub 3}U than is PMe{sub 3}.

Direct detection of {sup 14}C by accelerator mass spectrometry has proved to be a much more sensitive method for radiocarbon dating than the decay counting method invented earlier by Libby. A small cyclotron (the cyclotrino'') was proposed for direct detection of radiocarbon in 1980. This combined the suppression of background through the use of negative ions, which had been used effectively in tandem accelerators, with the high intrinsic mass resolution of a cyclotron. Development of a small electrostatically-focused cyclotron for use as a mass spectrometer was previously reported but the sensitivity needed for detection of {sup 14}C at natural abundance was not achieved. The major contributions of this work are the integration of a high current external ion source with a small flat-field, electrostatically-focused cyclotron to comprise a system capable of measuring {sup 14}C at natural levels, and the analysis of ion motion in such a cyclotron, including a detailed analysis of phase bunching and its effect on mass resolution. A high current cesium sputter negative ion source generates a beam of carbon ions which is pre-separated with a Wien filter and is transported to the cyclotron via a series of electrostatic lenses. Beam is injected radially into the cyclotron …

This document discusses a support provided for use in a thermionic converter to support an end of an emitter to keep it out of contact with a surrounding collector while allowing the emitter end to move axially as its temperature changes. The emitter end is supported by a spring structure that includes a pair of Belleville springs, and the spring structure is supported by a support structure fixed to the housing that includes the collector. The support structure is in the form of a sandwich with a small metal spring-engaging element at the front end, a larger metal main support at the rear end that is attached to the housing, and with a ceramic layer between them that is bonded by hot isostatic pressing to the metal element and metal main support. The spring structure can include a loose wafer captured between the Belleville springs. 7 figs.

In this thesis, crossed-molecular-beams studies of the reaction D + H{sub 2} {yields} DH + H at collision energies of 0.53 and 1.01 eV are reported. Chapter 1 provides a survey of important experimental and theoretical studies on the dynamics of the hydrogen exchange reaction. Chapter 2 discusses the development of the excimer-laser photolysis D atom beam source that was used in these studies and preliminary experiments on the D + H{sub 2} reaction. In Chapter 3, the differential cross section measurements are presented and compared to recent theoretical predictions. The measured differential cross sections for rotationally excited DH products showed significant deviations from recent quantum scattering calculations, in the first detailed comparison of experimental and theoretical differential cross sections. These results indicate that further work on the H{sub 3} potential energy surface, particularly the bending potential, is in order.