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Impulsive ion acceleration in earth's outer magnetosphere

Description: Considerable observational evidence is found that ions are accelerated to high energies in the outer magnetosphere during geomagnetic disturbances. The acceleration often appears to be quite impulsive causing temporally brief (10's of seconds), very intense bursts of ions in the distant plasma sheet as well as in the near-tail region. These ion bursts extend in energy from 10's of keV to over 1 MeV and are closely associated with substorm expansive phase onsets. Although the very energetic ions… more
Date: January 1, 1985
Creator: Baker, D.N. & Belian, R.D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Neutron induced current pulses in fission chambers. [LMFBR]

Description: The mechanism of neutron induced current pulse generation in fission chambers is discussed. By application of the calculated detector transfer function to proposed detector current pulse shapes, and by comparison with actually observed detector output voltage pulses, a credible, semi-empirical, trapezoidal pulse shape of chamber current is obtained.
Date: January 1, 1978
Creator: Taboas, A.L. & Buck, W.L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Some general properties of stimulated Raman propagation with pump depletion, transiency and dispersion

Description: This note considers some of the properties of the Stokes pulse that grows from a specified seed pulse in the presence of a strong pump pulse as it propagates through a dispersive atomic vapor. We first present an generic dimensionless form for the coupled equations that govern the propagation of pump and Stokes fields or collinear plane-wave pulses. By treating the two fields we permit pump depletion. We include transient atomic response (as embodied in the Raman coherence), but neglect changes… more
Date: August 2, 1991
Creator: Shore, B. W.; Lowder, S. & Johnson, M. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Fresh-Bunch' technique in FELs

Description: The 'Fresh Bunch' technique is being proposed as a method of increasing the gain and power of FEL amplifiers in which the length of the optical radiation pulse is shorter than the length of the electron bunch. In multi-stage FEL, electron beam energy spread is increased by the FEL interaction in the early stages. In the 'Fresh Bunch' technique, the low energy spread of the electron beam is recovered by shifting the radiation pulse to an undisturbed part of the electron bunch, thus improving the… more
Date: January 1, 1991
Creator: Ben-Zvi, Ilan; Yang, K. M. & Yu, L. H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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High-field bipolar loss measurement apparatus

Description: An apparatus was constructed to measure dissipation in superconducting wire in high alternating fields. The apparatus will be used to make measurements on conductors which must operate in fields up to 7.0 T and rates of field change up to 15 T/s. The magnet for this facility is wound of uninsulated, 15 strand Rutherford cable in which the strand is a 0.812 mm diameter, fully mixed matrix, Cu plus CuNi, multifilament NbTi conductor. The coil is wound in a bath cooled configuration with an overal… more
Date: January 1, 1980
Creator: Thullen, P.; Weldon, D. & Wollan, J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Research for Electric Energy Systems

Description: This report documents the technical progress in investigations. The first investigation is concerned with the measurement of magnetic fields in support of epidemiogical and in vitro studies of biological field effects. NIST cohosted a workshop on exposure and biological parameters that should be considered during the vitro studies with extremely low frequency (ELF) magnetic and electric fields. Also, equations were developed to predict the magnetic field in a parallel plate magnetic field expos… more
Date: June 1, 1991
Creator: Anderson, W.E. (ed.)
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Focus wave modes in homogeneous Maxwell's equation - TE-mode

Description: Mathematical formulations are presented for TE-mode, three-dimensional, solitary electromagnetic pulses propagating in free space. The pulses are required to satisfy the homogeneous Maxwell's equations, have a three-dimensional pulse structure, have no charge, move at light velocity in straight lines, have nondispersive pulses for all time, and have finite electromagnetic energy. (LEW)
Date: January 1, 1982
Creator: Brittingham, J.N.
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Partner: UNT Libraries Government Documents Department
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Enhanced lower hybrid penetration via intense multi-microsecond pulses

Description: Applying lower-hybrid power in short, intense pulses can overcome Landau damping, allowing penetration into the core of reactor-grade plasmas. We present theoretical description of the absorption which accounts for transient collisional effects as well as nonlinear broadening of the resonant plateau. We show results from ray-tracing calculations which include the nonlinear absorption. We also derive the conditions required for pump depletion by parametric instabilities, and assess density deple… more
Date: January 1, 1991
Creator: Cohen, R. H.; Rognlien, T. D. (Lawrence Livermore National Lab., CA (United States)); Bonoli, P. T. & Porkolab, M. (Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center)
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Partner: UNT Libraries Government Documents Department
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Lead acid battery pulse discharge investigation. Final report

Description: The effects of high current pulses caused by electric vehicle silicon-controlled rectifier and transistor chopper controllers on battery energy, lifetime, and microstructure were studied. Test equipment and results are described. It was found that the energy of improved golf cart-type batteries deteriorated under pulsed conditions by about 10% with respect to dc conditions for pulses between 16 and 333 Hz - no difference was noted above 333 Hz. Frequencies and duty cycles characteristic of elec… more
Date: April 1, 1980
Creator: Dowgiallo, E
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A PULSED EDDY CURRENT TEST SYSTEM USING REFLECTED FIELDS

Description: An eddy current test system is described in which the test information is detected as a series of fields reflected from the metal surface and interior. Pulsed electromagnetic fields are caused to impinge upon the test specimen. These fields are restricted to a small cross sectional area over a path in space long enough to be useful for test purposes by devices called mask-apenture assemblies. This approach provides a number of advantages over conventional eddy current methods of comparable capa… more
Date: June 11, 1962
Creator: Renken, C. J.
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Partner: UNT Libraries Government Documents Department
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Determination of the composition of ordered Pt/sub 3/Co by atom-probe field-ion microscopy: intrinsic problems

Description: Atom-probe field-ion microscope (FIM) analyses were performed on specimens of fully ordered Pt/sub 3/Co. The purpose of the investigation was to study the effects of different important experimental variables on the composition measured by the atom probe technique. The dependence of the alloy's composition on the following variables was determined: (1) pulse fraction (f); (2) specimen temperature; (3) crystal plane; and (4) field-evaporation rate. It was demonstrated that the composition determ… more
Date: May 1, 1980
Creator: Yamamoto, M. & Seidman, D. N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Evolution of shiva laser alignment systems

Description: The Shiva oscillator pulse is preamplified and divided into twenty beams. Each beam is then amplified, spatially filtered, directed, and focused onto a target a few hundred micrometers in size producing optical intensities up to 10/sup 16/W/cm/sup 2/. The laser was designed and built with three automatic alignment systems: the oscillator alignment system, which aligns each of the laser's three oscillators to a reference beamline; the chain input pointing system, which points each beam into its … more
Date: July 1, 1980
Creator: Boyd, R.D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Model of beam head erosion

Description: An analytical model of beam head dynamics is presented, leading to an estimate of the erosion rate due to the combined effects of Ohmic dissipation and scattering. Agreement with the results of a computer simulation and detailed one-dimensional computations is good in all respects except for the scaling of the erosion rate with net current.
Date: August 8, 1980
Creator: Lee, Edward P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Neutron cross section measurements at ORELA

Description: ORELA (Oak Ridge Electron Linear Accelerator) has been for the last decade the most powerful and useful pulsed neutron time-of-flight facility in the world, particularly in the broad midrange of neutron energies (10 eV to 1 MeV). This position will be enhanced with the addition of a pulse narrowing prebuncher, recently installed and now under test. Neutron capture, fission, scattering, and total cross sections are measured by members of the Physics and Engineering Physics Divisions of ORNL, and… more
Date: January 1, 1979
Creator: Dabbs, J. W. T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A five-picosecond electron pulse from ANL (Argonne National Laboratory) L-Band Linac

Description: The pulse-compression system of the Argonne National Laboratory Chemistry Division L-Band Linac, presented at the 1986 Linear Accelerator Conference at Stanford, California, has been completed. A five-picosecond-wide electron pulse containing 6 {times} 10{sup {minus}9} coulomb charge has been achieved. Acceleration parameters and the pulse-width measurement technique are discussed, and future plans for the utilization of this pulse in radiation chemistry studies are presented. 5 refs., 4 figs.
Date: January 1, 1989
Creator: Cox, G. L.; Jonah, C. D.; Ficht, D. T.; Mavrogenes, G. S. & Sauer, M. C. Jr.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Preliminary simulation studies of accelerator cavity loading

Description: Two-dimensional simulations of loading effects in a 350 MHz accelerator cavity have been performed. Electron currents of 1-10 kA have been accelerated in 5 MV/m fields. Higher order cavity modes induced by the beam may lead to emittance growth. Operation in an autoaccelerator mode has been studied.
Date: June 1, 1980
Creator: Faehl, R.J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Development of high-reliability, multikilohertz repetition-rate, fast-discharge components

Description: The two basic components in pulsed-power technology are capacitors and switches. In order to develop these high-voltage components, a unique laboratory has been constructed using state-of-the-art diagnostic and shielding techniques. The laboratory is comprised of three basic systems: charging systems, (2) diagnostic systems, and (3) grounding and shielding systems.
Date: January 1, 1980
Creator: McDuff, G.; Rust, K.; Sarjeant, W. J. & Mace, P. N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Alpha-contained laboratory scale pulse column facility for SRL

Description: For studying solvent extraction processes, a laboratory-sized pulse column facility was constructed at the Savannah River Laboratory. This facility, in conjunction with existing miniature mixer-settler equipment and the centrifugal contactor facility currently under construction at SRL, provides capability for cross comparison of solvent extraction technology. This presentation describes the design and applications of the Pulse Column Facility at SRL.
Date: January 1, 1980
Creator: Reif, D. J.; Cadieux, J. R.; Fauth, D. J. & Thompson, M. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Perturbation-polynomial expansion formulation of 3-D eddy current problems

Description: A pulsed magnetic field is required in tokamak fusion machines. Eddy currents produced by the pulsed field may produce undesirable effects, e.g., in the mechanical loading of the vacuum vessel, heating in the magnet and structure, and field ripple in the plasma region. A method has been developed earlier to calculate the eddy current produced in a thin object by the linear ramping of a magnetic dipole. Here extension of the method to calculate the eddy current induced in three-dimensional objec… more
Date: January 1, 1977
Creator: Yeh, H.T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Polarizability corrections in stimulated Raman propagation

Description: Traditional descriptions of stimulated Raman scattering relate the various Stokes and anti-Stokes fields to the incident pump field by means of a polarizability (tensor). This description is usable for pulsed radiation but it fails when the pump carrier frequency coincides with a resonant frequency of the medium. We here describe a simple procedure for correcting the traditional polarizability approximation for pulse envelopes so as to account for effects of finite pump bandwidth. The correctio… more
Date: July 30, 1991
Creator: Shore, B. W.; Johnson, M. A. & Lowder, S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Technology development for high-salinity geothermal resources

Description: An impulse turbine for Total Flow utilization of geothermal fluids was tested. Performance measurements verify the calculational model. The research goal of 70% engine efficiency remains credible. Addition of acid to the brine prevents scaling and precipitation at moderate costs. Corrosion and erosion of turbine materials for the Total Flow Process are not severe. (JB)
Date: August 5, 1977
Creator: Lundberg, A.W.
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Partner: UNT Libraries Government Documents Department
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Opportunities in pulse combustion

Description: In most pulse combustors, the combustion occurs near the closed end of a tube where inlet valves operate in phase with the pressure amplitude variations. Thus, within the combustion zone, both the temperature and the pressure oscillate around a mean value. However, the development of practical applications of pulse combustion has been hampered because effective design requires the right combination of the combustor's dimensions, valve characteristics, fuel/oxidizer combination, and flow pattern… more
Date: October 1, 1985
Creator: Brenchley, D.L. & Bomelburg, H.J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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