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Fast Electronics in High-Energy Physics (open access)

Fast Electronics in High-Energy Physics

A brief review of fast electronics is given, leading up to the present state of the art. Cherenkov counters in high-energy physics are discussed, including an example of a velocity-selecting Cherenkov counter. An electronic device to aid in aligning external beams from high-energy accelerators is described. A scintillation-counter matrix to identify bubble chamber tracks is discussed. Some remarks on the future development of electronics in high-energy physics experiments are included.
Date: August 8, 1958
Creator: Weigand, Clyde
System: The UNT Digital Library
The Bevatron (open access)

The Bevatron

None
Date: November 8, 1958
Creator: Lofgren, Edward J.
System: The UNT Digital Library
An Automatic Lithium Drifting Apparatus for Silicon and Germanium Detectors (open access)

An Automatic Lithium Drifting Apparatus for Silicon and Germanium Detectors

Drifting a thick lithium-drifted counter (silicon and germanium) is a time-consuming operation that frequently results in a poor device, owing to inadequate knowledge of progress of the drifting operation. The drifting apparatus described here automatically controls the temperature of the detector that is being drifted to maintain the leakage current at a preselected value. While drifting proceeds, a continuous measurement is made of the distance of the lithium-drifted region from the opposite face of the wafer. When the drifted region reaches 30 mil or less from the back of the wafer a meter indicates the thickness of the undrifted region and, when this thickness falls below a preselected value, the temperature of the detector is automatically reduced to room temperature. The need for constant supervision of the drifting operation is thereby eliminated, and reliance on theoretical drift-rate calculations to predict the drift-through time is avoided. The technique has been applied to the manufacture of lithium-drifted silicon detectors with excellent results. The application of the technique to lithium-drifted germanium {gamma} detectors is also discussed briefly.
Date: February 8, 1964
Creator: Goulding, Fred S. & Hansen, W. L.
System: The UNT Digital Library
CORRELATIONS BETWEEN PHOTOINDUCED EPR AND PHOTOCONDUCTIVITY INTONE-THF SOLUTION CHARGE-TRANSFER COMPLEX (open access)

CORRELATIONS BETWEEN PHOTOINDUCED EPR AND PHOTOCONDUCTIVITY INTONE-THF SOLUTION CHARGE-TRANSFER COMPLEX

Reversible photoinduced electron paramagnetic resonance (EPR) signals and photoconductivity were observed when a solution of tetracyancethylene (TCNE) in tetrahydrofuran (THF) was irradiated in the charge-transfer band of the complex formed between these two compounds. The eleven-line hyperfine structure of the EPR spectrum which was obtained demonstrated the presence of TCNE negative ion radical. The concentration of this radical was found to be directly proportional to the square root of the light intensity. Second order decay kinetics were followed when the light was shut off. Both the EPR signal and the photoconductivity rose initially as the square of the time. The latter portions of the growth curves could be fit to the latter portions of a hyperbolic tangential growth curve. From these data a reaction mechanism was proposed. The rate law dn/dt + kn{sup 2} = {alpha}L(1-e{sup -{beta}t}) = 0, where n = the concentration of radicals, t = the time, k, {alpha}, and {beta} are rate constants, and L = the light intensity, described both the photo-induced EPR and the photoconductivity within the limits of experimental accuracy.
Date: December 8, 1964
Creator: Ilten, David F. & Calvin, Melvin
System: The UNT Digital Library
Ultrastructure of Azotobacter vinelandii (open access)

Ultrastructure of Azotobacter vinelandii

Article discussing research on vegetative cells and cysts for Azotobacter vinelandii 12837 prepared for electron microscopy by several methods assumed to preserve structural details destroyed by techniques previously reported in literature.
Date: August 8, 1970
Creator: Vela, G. Roland, 1927-; Cagle, Gerald D. & Holmgren, P. R.
System: The UNT Digital Library
Environmental Considerations in Alternate Fusion Reactor Blankets (open access)

Environmental Considerations in Alternate Fusion Reactor Blankets

None
Date: September 8, 1974
Creator: Johnson, A. B., (Jr.) & Young, J. R.
System: The UNT Digital Library
Multi-step laser spectroscopy in atomic uranium. [Crossed beams] (open access)

Multi-step laser spectroscopy in atomic uranium. [Crossed beams]

The use of multistep photoionization techniques to measure lifetimes, cross sections, and branching ratios in uranium is described. The measurement of autoionization behavior, the assignment of new levels, and the observation of Rydberg states are also described. Experimental data are presented for all parameters. (auth)
Date: December 8, 1975
Creator: Solarz, R. W.; Paisner, J. A.; Carlson, L. R.; May, C. A. & Johnson, S. A.
System: The UNT Digital Library
Predicting explosion-generated permeability around geothermal wells (open access)

Predicting explosion-generated permeability around geothermal wells

A theoretical expression showing the radial dependence of permeability in geologic media as a function of the distance from the point of detonation has been derived. This relationship shows that created permeability decreases as a function of radius (1/r/sup 5/ around a spherical blast and 1/r/sup 4/ around a cylindrical shot). Excellent correlation was found when this prediction was compared with permeability measurements made around the site of the Hardhat nuclear event fired in granodiorite and a chemical explosive detonated in coal. (auth)
Date: January 8, 1976
Creator: McKee, C. R. & Hanson, M. E.
System: The UNT Digital Library
Overview of the Imperial Valley Environmental Project. [Environmental effects associated with development of geothermal resources] (open access)

Overview of the Imperial Valley Environmental Project. [Environmental effects associated with development of geothermal resources]

The Lawrence Livermore Laboratory has been appointed by the U.S. Energy Research and Development Administration to be the lead laboratory for carrying out a long-term project to acquire complete understanding of the environmental quality in the Imperial Valley of California prior to any major developments. The purpose of this project is to ensure that the development of geothermal resources proceeds on an environmentally sound basis. Consequently, the Imperial Valley Environmental Project (IVP) is committed to an intensive and comprehensive study designed to establish an environmental baseline for the Imperial Valley as well as to develop an understanding of the environmental and other effects associated with development of geothermal resources. The IVP is organized into seven main study sections, which when taken together cover all the significant issues and concerns. The sections are: Air Quality; Water Quality; Ecosystem Quality (Soil, Plants, Animals, etc.); Subsidence and Induced Seismicity; Health Effects; Socio-Economics; and an Integrated Assessment. (auth)
Date: April 8, 1976
Creator: Anspaugh, L. R. & Phelps, P. L.
System: The UNT Digital Library
Measurements of neutron-induced fission cross-section ratios involving isotopes of uranium and plutonium. [0. 001 to 30 MeV, cross sections] (open access)

Measurements of neutron-induced fission cross-section ratios involving isotopes of uranium and plutonium. [0. 001 to 30 MeV, cross sections]

A procedure, called the threshold cross section method was applied to our experimental data involving four uranium (/sup 233/U /sup 234/U, /sup 236/U, and /sup 238/U) and five plutonium (/sup 239/Pu, /sup 240/Pu, /sup 241/Pu, /sup 242/Pu, and /sup 244/Pu) isotopes to determine ratios of fission cross sections relative to /sup 235/U. The data were gathered using ionization fission chambers and the time-of-flight technique at the LLL 100-MeV electron linear accelerator: measurements span the neutron energy range of 0.001 to 30 MeV. Experimental uncertainties common to past measurements were either eliminated or significantly reduced in this study by use of the threshold method, thereby making higher accuracies possible. The cross section ratios are absolute in the sense that they do not depend on the work of others. Results from our ratios involving /sup 233/U, /sup 235/U, /sup 238/U, and /sup 239/Pu are used to illustrate this method.
Date: June 8, 1976
Creator: Behrens, J. W. & Carlson, G. W.
System: The UNT Digital Library
Semi-automated x-ray gauging process control system. [For pressed-material components] (open access)

Semi-automated x-ray gauging process control system. [For pressed-material components]

An x-ray gauging method was developed and a production gauging system was subsequently fabricated to control the quality of precision manufactured components. The gauging system measures via x-ray absorption the density of pressed finely divided solids held in a dissimilar container. The two dissimilar materials condition necessitated a ''two scan'' technique: first, the x-ray attenuation (absorption) of the empty container prior to loading and then, the attenuation of the loaded container are measured; that is, four variables. The system provided greatly improved product control via timely data feedback and increased product quality assurance via 100 percent inspection of product. In addition, it reduced labor costs, product cost, and possibilities for human errors.
Date: October 8, 1976
Creator: Draut, C. F. & Homan, D. A.
System: The UNT Digital Library
High pressure apparatus for hydrogen isotopes to pressures of 345 MPa (50,000 psi) and temperatures of 1200/sup 0/C (open access)

High pressure apparatus for hydrogen isotopes to pressures of 345 MPa (50,000 psi) and temperatures of 1200/sup 0/C

A functional new high pressure, high temperature apparatus for hydrogen isotopes uses an internally heated pressure vessel within a larger pressure vessel. The pressure capability is 345 MPa (50 K psi) at 1200/sup 0/C. The gas pressure inside the internal vessel is balanced with gas pressure in the external vessel. The internal vessel is attached to a closure and is also the sample container. Our design allows thin-walled internal vessel construction and keeps the sample from ''seeing'' the furnace or other extraneous environment. The sample container together with the closure can easily be removed and loaded under argon using standard glove-box procedures. The small volume of the inner vessel permits small volumes of gas to be used, thus increasing the sensitivity during pressure-volume-temperature (PVT) work.
Date: June 8, 1977
Creator: Lakner, J. F.
System: The UNT Digital Library
Reference mirror hybrid fusion-fission reactor design (open access)

Reference mirror hybrid fusion-fission reactor design

The status of the reference mirror hybrid reactor design being performed by LLL and General Atomic is summarized. The reactor parameters have been chosen to minimize the cost of producing fissile fuel for consumption in fission power reactors. The design draws on the experience developed at LLL in previous hybrid reactor conceptual designs and on GA expertise in gas-cooling technology and fission reactor mechanical design. As in the past, we have emphasized the use of existing technology where possible and a minimum extrapolation of technology otherwise. We consider our projections for the plasma physics parameters to be conservative, in that they are well-founded on the experiments in 2XIIB and the interpretation of these experiments.
Date: June 8, 1977
Creator: Bender, D. J.; Lee, J. D. & Neef, W. S.
System: The UNT Digital Library
1/5-scale experiment of a Mark I boiling-water reactor pressure-suppression system under hypothetical LOCA conditions (open access)

1/5-scale experiment of a Mark I boiling-water reactor pressure-suppression system under hypothetical LOCA conditions

Experimental results show the sensitivity of hydrodynamically generated vertical loads to changes in the drywell pressurization rate, downcomer submergence, and vent-line loss coefficient. Insignificant effects on peak vertical loads were observed when the vent-line loss was varied. Peak vertical loads can be reduced by adding initial drywell overpressure so that the downcomers are partly cleared of water. Spatial variation of pressure at about the time of vent clearing is seen in comparisons of data from locations along the axis of the toroidal wetwell.
Date: July 8, 1977
Creator: Pitts, J. H. & McCauley, E. W.
System: The UNT Digital Library
Evaluation of metal-foil strain gages for cryogenic application in magnetic fields (open access)

Evaluation of metal-foil strain gages for cryogenic application in magnetic fields

The requirement for the design and construction of large superconducting magnet systems for fusion research has raised a number of new questions regarding the properties of composite superconducting conductors. One of these, the effect of mechanical stress on the current-carrying capacity of Nb/sub 3/Sn, is of major importance in determining the feasibility of constructing large magnets with this material. A typical experiment for determining such data involves the measurement of critical current versus magnetic field while the conductor is being mechanically strained to various degrees. Techniques are well developed for the current and field measurements, but much less so for the accurate measurement of strain at liquid-helium temperature in a high magnetic field. A study was made of commercial, metal-foil strain gages for use under these conditions. The information developed can also be applied to the use of strain gages as diagnostic tools in superconducting magnets.
Date: July 8, 1977
Creator: Freynik, H. S. Jr.; Roach, D. R.; Deis, D. W. & Hirzel, D. G.
System: The UNT Digital Library
Diagnostics systems developments and applications for laser fusion experiments (open access)

Diagnostics systems developments and applications for laser fusion experiments

A variety of systems are required for adequate diagnostics of laser fusion experiments. Picosecond scale temporal measurements are typically made with ultrafast streak cameras. Visible and x-ray sensitive streak cameras with resolutions of 6 psec and 15 psec, respectively, and dynamic recording range in excess of 10/sup 3/ are in regular use on experiments at Livermore. The characteristics of these cameras and their applications to target experiment diagnostics are described. The development and testing of a prototype ultrafast framing system is discussed. Because of the need for ''real time'' data acquisition, analysis, and control systems, techniques for providing directly computer interfaced image data from streak and framing cameras and optical imaging systems are being developed. The status of these developments and the characteristics of the computer interfaced data and control systems on Argus and Shiva are summarized.
Date: September 8, 1977
Creator: Coleman, L. W.
System: The UNT Digital Library
Schemes for anti pp interactions at ISABELLE (open access)

Schemes for anti pp interactions at ISABELLE

Various schemes for obtaining anti pp interactions are outlined, and the luminosities obtainable for each case calculated. In the simplest realistic case, a luminosity of 1.3 x 10/sup 29/ is obtained with a 13 hour filling time. The addition of special rf systems in both the AGS and ISABELLE give a scheme with luminosity 8 x 10/sup 29/ in 6 hours. The use of stochastic cooling to stack raises the luminosity to as high as 10/sup 31/ but the filling time is then 68 hours. Finally a scheme is considered that uses a special 30 GeV capture ring. With this, a luminosity of 10/sup 31/ could be achieved after 20 hours, or higher if a larger filling time were acceptable. Further gains could be made if a smaller proton spot on the target is used but a simple calculation suggests that even the spot size assumed may explode the target too fast.
Date: September 8, 1977
Creator: Palmer, Robert B.
System: The UNT Digital Library
Computer program SCAP-BR for gamma-ray streaming through multi-legged ducts (open access)

Computer program SCAP-BR for gamma-ray streaming through multi-legged ducts

A computer program, SCAP-BR, has been developed at Burns and Roe for the gamma-ray streaming analysis through multi-legged ducts. SCAP-BR is a modified version of the single scattering code, SCAP, incorporating capabilities of handling multiple scattering and volumetric source geometries. It utilizes the point kernel integration method to calculate both the line-of-sight and scattered gamma dose rates by employing the ray tracing technique through complex shield geometries. The multiple scattering is handled by a repeated process of the single scatter method through each successive scatter region and collapsed pseudo source meshes constructed on the relative coordinate systems. The SCAP-BR results have been compared with experimental data for a Z-type (three-legged) concrete duct with a Co-60 source placed at the duct entrance point. The SCAP-BR dose rate predictions along the duct axis demonstrate an excellent agreement with the measured values.
Date: December 8, 1977
Creator: Byoun, T. Y.; Babel, P. J. & Dajani, A. T.
System: The UNT Digital Library
Fusion reactor requirements and systems for energy storage and transfer (open access)

Fusion reactor requirements and systems for energy storage and transfer

Energy storage and transfer requirements for many of the present day reactor systems are listed. Two ohmic heating (OH) requirements, those for toroidal Z-pinches and Tokamaks, are described in more detail. Technologies envisioned for the power conditioning circuitry are discussed.
Date: May 8, 1978
Creator: Thomassen, K.I.; Hagenson, R.L. & Thullin, P.
System: The UNT Digital Library
High performance inertial fusion targets (open access)

High performance inertial fusion targets

Inertial confinement fusion (ICF) target designs are considered which may have very high gains (approximately 1000) and low power requirements (< 100 TW) for input energies of approximately one megajoule. These include targets having very low density shells, ultra thin shells, central ignitors, magnetic insulation, and non-ablative acceleration.
Date: August 8, 1978
Creator: Nuckolls, J.H.; Bangerter, R.O.; Lindl, J.D.; Mead, W.C. & Pan, Y.L.
System: The UNT Digital Library
Mirror fusion test facility (open access)

Mirror fusion test facility

The MFTF is a large new mirror facility under construction at Livermore for completion in 1981--82. It represents a scaleup, by a factor of 50 in plasma volume, a factor of 5 or more in ion energy, and a factor of 4 in magnetic field intensity over the Livermore 2XIIB experiment. Its magnet, employing superconducting NbTi windings, is of Yin-Yang form and will weigh 200 tons. MFTF will be driven by neutral beams of two levels of current and energy: 1000 amperes of 20 keV (accelerating potential) pulsed beams for plasma startup; 750 amperes of 80 keV beams of 0.5 second duration for temperature buildup and plasma sustainment. Two operating modes for MFTF are envisaged: The first is operation as a conventional mirror cell with n/sup tau/ approximately equal to 10/sup 12/ cm/sup -3/ sec, W/sub i/ = 50 keV, where the emphasis will be on studying the physics of mirror cells, particularly the issues of improved techniques of stabilization against ion cyclotron modes and of maximization of the electron temperature. The second possible mode is the further study of the Field Reversed Mirror idea, using high current neutral beams to sustain the field-reversed state. Anticipating success in the coming …
Date: September 8, 1978
Creator: Post, Richard F.
System: The UNT Digital Library
Physics of field reversed mirrors (open access)

Physics of field reversed mirrors

Since the earliest days of fusion research it has been hoped that diamagnetic currents flowing in a plasma could be used to help confine the plasma. Recently this hope has been strengthened both by theoretical advances and by experimental results made possible by technological developments. On the theoretical front analytical treatments and computer simulation studies have demonstrated equilibrium solutions existing both in the fluid limit and in the large-orbit limit. Progress has also been made in determining the conditions required for the stability of field-reversed entities. It appears that configurations of the general form of fat doughnuts, possibly elongated to napkin-ring form, represent stable states. Building on previous experimental work, several investigators have been able to create field-reversed states. One method, based on the ASTRON idea of Christofilos, traps an intense relativistic electron beams (REB) to create a field-reversing current ring. Other approaches use either the reversed field theta pinch technique or REB pulses to create field-reversing diamagnetic currents in a long cylindrical plasma. In the former method, millisecond-long field-reversing electron rings have been achieved; in the latter method field-reversed plasma states lasting 30 to 50 microseconds have been achieved. Another approach under investigation is the Field Reversed Mirror (FRM) …
Date: September 8, 1978
Creator: Post, Richard F.
System: The UNT Digital Library
Response of Inconel 600 to simulated fusion reactor irradiation (open access)

Response of Inconel 600 to simulated fusion reactor irradiation

Inconel 600 was irradiated in HFIR to provide a partial simulation of fusion reactor service. Samples were irradiated at 55 to 700/sup 0/C, to investigate swelling and postirradiation tensile properties as a function of irradiation and test temperatures under conditions of concurrent displacement damage and helium production. Helium contents from 600 to 1800 appm and displacement levels of 4 to 9 dpa were achieved, and the results are used to estimate performance in a fusion reactor environment. Tensile property measurements and fractography on the same samples showed strength values increased for irradiation at 55 to 400/sup 0/C but decreased below unirradiated values for irradiations at 600 and 700/sup 0/C.
Date: September 8, 1978
Creator: Wiffen, F.W.
System: The UNT Digital Library
Potential contribution of solar energy in the Northwest (open access)

Potential contribution of solar energy in the Northwest

Estimates on the ability of solar energy to supply US energy needs vary from 0 to 25%. It is generally thought that solar can supply as much as we want it to up to 25% in the Northwest by the year 2000 providing an all-out effort is applied now to develop solar energy. The factors affecting the extent of solar utilization are discussed; they are more institutional (inertia, experience, legal, social) than technological or economical. Because of its climate, unique power system, and amount of sunshine, the Northwest is one of the best places in the US for solar energy utilization. Solar energy used in the Northwest is more likely to meet needs that would otherwise be met by new thermal electric plants than is the case in most places.
Date: November 8, 1978
Creator: Drumheller, K.
System: The UNT Digital Library