Long wavelength end-effect undulator radiation (Transition Undulator Radiation) (open access)

Long wavelength end-effect undulator radiation (Transition Undulator Radiation)

As first pointed out by K.-J. Kim, undulator radiation contains a broad-band component in the long wavelength region. This radiation is due to the change in longitudinal velocity of an electron upon entering and leaving an undulator. The radiation pattern is a hollow cone, peaked in the forward direction, with an opening angle of approximately 1/{gamma}, with a spectrum covering a wide range, including the infra-red and the visible. The radiation is radially polarized, analogous to transition radiation, and exhibits interference effects between the entrance and exit ends of the undulator, similar to the interference effects observed for transition radiation from a thin slab of material. A straightforward application of formulas from Jackson ({ital Classical Electrodynamics}) results in a closed form exact expression for the low frequency limit of this novel radiation effect, Transition Undulator Radiation or TUR. 3 refs., 3 figs.
Date: January 29, 1996
Creator: Kincaid, B.M.
Object Type: Report
System: The UNT Digital Library
Perpendicular giant magnetoresistance in a 0.4 {mu}m diameter multilayer sensor (open access)

Perpendicular giant magnetoresistance in a 0.4 {mu}m diameter multilayer sensor

We have fabricated a novel GMR ML flux sensor that is designed to operate in the CPP mode. The GMR sensor is a 0.4 {mu}m diameter, 0.09 {mu}m high Cu-Co ML pedestal. The sensors are patterned using electron beam lithography. The Al{sub 2}O{sub 3}-TiC substrate is coated with a sputter deposited Al{sub 2}O{sub 3} film that is polished to <0.2 nm RMS roughness. Contact to the bottom of the GMR sensor is made by depositing the Cu-Co multilayers onto a smooth 0.45 {mu}m thick Mo-Si ML stack. The top contact is self-aligned to the GMR sensor. This is accomplished, in part, by CMP. The top and bottom contact layers are electrically isolated by a PECVD Si{sub 3}N{sub 4} film. The configuration of the contacts allows four point probe resistance measurements. The GMR response of these 0.4 {mu}m diameter sensors is 12%.
Date: February 29, 1996
Creator: Spallas, J. & Huai, Y., Vernon, S.
Object Type: Article
System: The UNT Digital Library
Advanced emissions control development project. Final report, November 1, 1993--February 29, 1996. Phase I (open access)

Advanced emissions control development project. Final report, November 1, 1993--February 29, 1996. Phase I

The primary objective of the Advanced Emissions Control Development Program (AECDP) is to develop practical, cost-effective strategies for reducing the emissions of air toxics from coal-fired boilers. Ideally, the project aim is to effectively control air toxic emissions through the use of conventional flue gas cleanup equipment such as electrostatic precipitators (ESPs), fabric filters (baghouses), and wet flue gas desulfurization. B&W`s Clean Environment Development Facility (CEDF) and the AECDP equipment combined to form a state-of-the-art facility for integrated evaluation of combustion and post-combustion emissions control options. Phase I activities were primarily directed at providing a reliable, representative test facility for conducting air toxic emission control development work later in the project. This report summarizes the AECDP Phase I activities which consisted of the design, installation, shakedown, verification, and air toxics benchmarking of the AECDP facility. The AECDP facility consists of an ESP, pulse-jet baghouse, and wet scrubber. All verification and air toxic tests were conducted with a high sulfur, bituminous Ohio coal. In order to successfully apply the results of the program to utility systems, the relationship between the performance of the CEDF/AECDP test equipment and commercial units had to be established. The first step in the verification process was …
Date: February 29, 1996
Creator: Farthing, G.A.
Object Type: Report
System: The UNT Digital Library
Status of thermal loading evaluations for a potential repository (open access)

Status of thermal loading evaluations for a potential repository

The effect that thermal loading has on the natural and engineered systems needs to be understood and demonstrated with reasonable assurance in the Viability Assessment and the License Application process for a potential underground high level waste repository at Yucca Mountain. Thermal loading can be defined in a number of ways but it basically is the amount of decay heat from the spent nuclear fuel produced per unit area and is related to the emplacement density of fuel. This paper provides an overview of the status of the development of the technical basis for a thermal loading decision for a potential repository at Yucca Mountain and emphasizes recent analyses conducted.
Date: January 29, 1996
Creator: Saterlie, S. F.
Object Type: Article
System: The UNT Digital Library
Selenium emission control at high temperatures with mineral sorbents. Final report, September 1, 1994--February 29, 1996 (open access)

Selenium emission control at high temperatures with mineral sorbents. Final report, September 1, 1994--February 29, 1996

The focus of this project is on toxic metal removal by sorbent injection in the upper furnace and economizer sections of a coal- fired boiler. Selenium was chosen as the candidate heavy metal to be studied because of its high volatility and associated difficulties in removal. A thorough mechanistic investigation of the SeO{sub 2}-Ca(OH){sub 2} interaction at both medium and high temperatures has been conducted in this project. Experiments were performed in the two temperature ranges in the presence and absence of O{sub 2}; desorption studies were conducted to characterize the nature of interaction; and XRD/XPS and Ion Chromatography studies were performed for species identification. It was inferred from these findings that the selenium capture was significantly more in the medium temperature range (450-650{degrees}C) than in high temperature range (800-1000{degrees}C) and the captured selenium species in the medium temperature range is in the form of calcium selenite (CaSeO{sub 3}) and a reaction scheme was proposed for the CaO/SeO{sub 2} interaction: CaO (s) + SeO{sub 2} (g) = CaSeO{sub 3} (s). This reaction process does not require the participation of oxygen, as was confirmed by various analytical techniques and supported by the experimental evidence. Results of the high-temperature studies indicate much …
Date: February 29, 1996
Creator: Ghosh-Dastidar, Abhijit; Mahuli, Suhas; Agnihotri, Rajeev & Fan, Liang-Shih
Object Type: Report
System: The UNT Digital Library
Co-firing high sulfur coal with refuse derived fuels. Technical progress report No. 6, January--March 1996 (open access)

Co-firing high sulfur coal with refuse derived fuels. Technical progress report No. 6, January--March 1996

The objectives for this quarter of study on the co-firing of high sulfur coals with refuse derived fuels were two-fold. First, the effects of different experimental parameters such as temperature, flow rates and reaction times on the formation of chlorinated organic compounds were studied using the tubular furnace as a reactor followed by GC/MS analysis. Secondly, the effect of fuel/air ratio on the flue gas composition and combustion efficiency were studied with the AFBC system.
Date: February 29, 1996
Creator: Pan, W. P.; Riley, J. T. & Lloyd, W. G.
Object Type: Report
System: The UNT Digital Library