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Operational characteristics and analysis of the immersed-Bz diode on RITS-3.

Description: The immersed-B{sub z} diode is being developed as a high-brightness, flash x-ray radiography source. This diode is a foil-less electron-beam diode with a long, thin, needle-like cathode inserted into the bore of a solenoid. The solenoidal magnetic field guides the electron beam emitted from the cathode to the anode while maintaining a small beam radius. The electron beam strikes a thin, high-atomic-number anode and produces bremsstrahlung. We report on an extensive series of experiments where a… more
Date: February 1, 2006
Creator: Bruner, Nichelle "Nicki"; Oliver, Bryan Velten; Portillo, Salvador; Puetz, Elizabeth A.; Johnston, Mark D.; Welch, Dale Robert et al.
Partner: UNT Libraries Government Documents Department
open access

Final Report: Wetted Cathodes for Low-Temperature Aluminum Smelting

Description: A low-temperature aluminum smelting process being developed differs from the Hall-Heroult process in several significant ways. The low-temperature process employs a more acidic electrolyte than cryolite, an alumina slurry, oxygen-generating metal anodes, and vertically suspended electrodes. Wetted and drained vertical cathodes are crucial to the new process. Such cathodes represent a significant portion of the capital costs projected for the new technology. Athough studies exist of wetted catho… more
Date: September 30, 2002
Creator: Brown, Craig W.
Partner: UNT Libraries Government Documents Department
open access

The Distribution of Energy at the Cathode of a Glow Discharge

Description: The anodes of a mercury vapor rectifier are the cathodes for the current in the so-called "non-conducting direction." If the voltage is sufficient, a glow discharge occurs in the on-conducting direction. It is of considerable practical importance to know how much energy this glow discharge carries over to the cathodes.
Date: unknown
Creator: Gunther-Schulze, A.
Partner: UNT Libraries Government Documents Department
open access

A novel electron gun with an independently addressable cathode array.

Description: The design of a novel electron gun with an array of independently addressable cathode elements is presented. Issues relating to operation in a 6.5 Tesla axial magnetic field are discussed. Simulations with the TriComp [1] electromagnetic field code that were used to determine the space charge limited tube characteristic and to model focusing of the electron beam in the magnetic field are reviewed. Foil heating and stress calculations are discussed. The results of CYLTRAN [2] simulations yieldin… more
Date: August 1, 2006
Creator: Rudys, Joseph Matthew; Reed, Kim Warren; Peña, Gary Edward & Schneider, Larry X.
Partner: UNT Libraries Government Documents Department
open access

Batteries: Overview of Battery Cathodes

Description: The very high theoretical capacity of lithium (3829 mAh/g) provided a compelling rationale from the 1970's onward for development of rechargeable batteries employing the elemental metal as an anode. The realization that some transition metal compounds undergo reductive lithium intercalation reactions reversibly allowed use of these materials as cathodes in these devices, most notably, TiS{sub 2}. Another intercalation compound, LiCoO{sub 2}, was described shortly thereafter but, because it was … more
Date: July 12, 2010
Creator: Doeff, Marca M
Partner: UNT Libraries Government Documents Department
open access

Some Physical Properties of Barium Oxide Thermocathodes

Description: The oxide thermocathode is the main element of numerous present day electronic instruments and installations. The work presented in this paper is an attempt to investigate the various phenomena which take place inside an actual thermocathode during electronic emission.
Date: unknown
Creator: Morgulis, N. D. & IAgovdik, V. S.
Partner: UNT Libraries Government Documents Department
open access

Nuclear Track Image Intensifier

Description: "Development of a nuclear track image intensifier which is to have a cathode dia. of 83 in. and an output screen dia. of 1 in. is reported. Spherical faceplates for the intensifier which were etched to a thickness of 0.025 in. over a dia. of 80 in. withstood a pressure differential of 2 atm. Techniques were developed to measure spectral energy distribution, phosphor burn characteristics, phosphor efficiency, and phosphor persistence. Thallium- activated RbI and CsI were evaluated for use in the… more
Date: September 30, 1960
Creator: DesRochers, R. D.; Stern, H. A. & Ezard, L. A.
Partner: UNT Libraries Government Documents Department
open access

Ultrahigh Vacuum Techniques

Description: "The photodesorption of gases from metals by uv photons has been studied with a high sensitivity mass spectrometer. A program to develop low-temperature cathodes is underway to study hydrogen interactions at various surfaces. Preliminary results on the degassing characteristics of an all metal system have been obtained."
Date: unknown
Creator: Fox, R. E.
Partner: UNT Libraries Government Documents Department
open access

Approaches to rid cathodic arc plasmas of macro- andnanoparticles: A review

Description: A major obstacle for the broad application of cathodic arc plasma deposition is the presence of micro- and nanoparticles in the plasma, also often referred to as 'macroparticles'. This paper reviews the formation of macroparticles at cathode spots, their interaction with the arc plasma and substrate, and macroparticle separation and removal from the plasma by various filtering methods. Nineteen variants of filters are discussed, including Aksenov's classic 90{sup o}-duct filter, filters of open… more
Date: June 1, 1999
Creator: Anders, Andre
Partner: UNT Libraries Government Documents Department
open access

On the Question of Ionization of Atoms and Neutralization of Ions on the Surface of a Cathode of Low Conductivity

Description: On the specificity of phenomena, occurring in the case of cathodes of low conductivity, the article considers the problem of ionization of atoms and neutralization of ions on their surfaces. At the same time the author demonstrates the peculiarities of these phenomena and their distinctness from the case of metallic surfaces.
Date: unknown
Creator: Morgulis, N, D.
Partner: UNT Libraries Government Documents Department
open access

Active Cathodes for Super-High Power Density Solid Oxide Fuel Cells Through Space Charge Effects

Description: This report briefly summarizes the work done over the duration of the project, beginning October 1, 2003 and ending September 30, 2005. This project was on understanding cathode mechanisms in intermediate temperature solid oxide fuel cells (SOFC) and developing superior cathodes.
Date: September 30, 2005
Creator: Virkar, Anil V.
Partner: UNT Libraries Government Documents Department
open access

Conditioning effects on La1-xSrxMnO3-Yttria stabilized Zirconia electrodes for thin-film solid oxide fuel cells

Description: Composite cathodes of 50/50 vol percent LSM-YSZ (La1-xSrxMnO3-yttria stabilized zirconia) were deposited onto dense YSZ electrolytes by a colloidal deposition technique. The cathode characteristics were then examined by scanning electron microscopy (SEM) and studied by an impedance spectroscopy (IS). Conditioning effects of the LSM-YSZ cathodes were seen, and remedies for these effects were proposed for improving the performance of a solid oxide fuel cell (SOFC). LSM surface contamination and m… more
Date: December 6, 2002
Creator: Lee, You-Kee; Kim, Jung-Yeul; Lee, Young-Ki; Kim, Insoo; Moon, Hee-Soo; Park, Jong-Wan et al.
Partner: UNT Libraries Government Documents Department
open access

Controlling the Plasma Flow in the Miniaturized Cylindrical Hall Thruster

Description: A substantial narrowmg of the plume of the cylindrical RaIl thruster (CRT) was observed upon the enhancement of the electron emission from the hollow cathode discharge, which implies the possibility for the thruster efficiency increase due to the ion beam focusing. It is demonstrated that the miniaturized CRT can be operated in the non-self-sustained regime, with the discharge current limited by the cathode electron emission. The thruster operation in this mode greatly expands the range of the … more
Date: March 4, 2008
Creator: Smirnov, A.
Partner: UNT Libraries Government Documents Department
open access

Particle-In-Cell/Monte Carlo Simulation of Ion Back Bombardment in Photoinjectors

Description: In this paper, we report on studies of ion back bombardment in high average current dc and rf photoinjectors using a particle-in-cell/Monte Carlo method. Using H{sub 2} ion as an example, we observed that the ion density and energy deposition on the photocathode in rf guns are order of magnitude lower than that in a dc gun. A higher rf frequency helps mitigate the ion back bombardment of the cathode in rf guns.
Date: March 2, 2009
Creator: Qiang, Ji; Corlett, John & Staples, John
Partner: UNT Libraries Government Documents Department
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Characterization of SEI layers on LiMn2O4 cathodes with in-situ spectroscopic ellipsometry

Description: In situ spectroscopic ellipsometry was employed to study the initial stage of SEI layer formation on thin-film LiMn{sub 2}O{sub 4} electrodes. It was found that the SEI layer formed immediately upon exposure of the electrode to EC/DMC (1:1 by vol) 1.0 M LiPF{sub 6} electrolyte. The SEI layer thickness then increased in proportion to a logarithmic function of elapsed time. In comparison, the SEI layer thickness on a cycled electrode increased in proportion to a linear function of the number of c… more
Date: August 30, 2004
Creator: Lei, Jinglei; Li, Lingjie; Kostecki, Robert; Muller, Rolf & McLarnon, Frank
Partner: UNT Libraries Government Documents Department
open access

Simulating Nonuniform Properties in Polymer-Electrolyte Fuel Cells

Description: In this transaction, results from mathematical, pseudo 2-D simulations are shown for four different thickness distributions of both the membrane and cathode catalyst layer. The results and subsequent analysis clearly demonstrate that the position along the gas channel is more important than the local thickness variations, especially for the membrane.
Date: July 1, 2006
Creator: Weber, Adam Z. & Newman, John
Partner: UNT Libraries Government Documents Department
open access

A study of surface film formation on LiNi0.8Co0.15Al0.05O2 cathodes u sing attenuated total reflection infrared spectroscopy

Description: The surface films formed on commercial LiNi0.8Co0.15Al0.05O2 cathodes (ATD Gen2) charged from 3.75V to 4.2V vs. Li/Li+ in EC:DEC - 1M LiPF6 were analyzed using ex-situ Fourier transform infrared spectroscopy (FTIR) with the attenuated total reflection (ATR) technique. A surface layer of Li2CO3 is present on the virgin cathode, probably from reaction of the active material with air during the cathode preparation procedure. The Li2CO3 layer disappeared even after soaking in the electrolyte, indic… more
Date: January 19, 2004
Creator: Song, S.-W.; Zhuang, G.V. & Ross Jr., P.N.
Partner: UNT Libraries Government Documents Department
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