Steady-state approximations in Raman excitation equations (open access)

Steady-state approximations in Raman excitation equations

This memo presents equations describing propagation of beams of nearly monochromatic radiation through a Raman-active molecular vapor, under conditions of steady excitation of quantum-mechanical molecules by classical radiation (that is, by radiation that comprises a large number of photons per mode). Such conditions apply in the continuous-wave experiments that are conducted to measure such properties as Raman gain or Raman scattering cross sections. Under those circumstances the propagation is described by rate equations for molecular excitation and rate equations for photon numbers. Although these conditions do not apply for short-pulse transient excitation, both types of processes are parameterized by the same molecular polarizability matrix elements. This memo discusses those parameters, as extracted from steady state observations.
Date: December 20, 1987
Creator: Shore, B. W.
Object Type: Report
System: The UNT Digital Library
Observation of anomalous low J-value Stokes and anti-Stokes lines in stimulated rotational Raman scattering over long air paths (open access)

Observation of anomalous low J-value Stokes and anti-Stokes lines in stimulated rotational Raman scattering over long air paths

Anomalous low-J-value Stokes and anti-Stokes lines in stimulated rotational Raman scattering are observed with large Fresnel number, linearly polarized beams. Forced light scattering at the rotational intermodulation frequency is also observed. Dynamics of the Stokes-anti-Stokes coupling will be discussed. 5 refs., 2 figs.
Date: November 20, 1987
Creator: Pennington, D.M. & Henesian, M.A.
Object Type: Article
System: The UNT Digital Library
Intense electron beams (open access)

Intense electron beams

This paper is concerned with intense electron beams, typically of the order of a few kA in current and up to tens of MeV in beam energy. A beam of this kind can be produced from induction machines, examples of which are the ERA (4 MeV, 1 kA) at Lawrence Berkeley Laboratory and the ASTRON (5 MeV, 500A), ETA (5 MeV, 10 kA), and ATA (50 MeV, 10 kA) at Lawrence Livermore National Laboratory (LLNL). The emphasis of the paper is on the characteristics of these beams and some applications. 13 refs., 2 figs. (LSP)
Date: October 20, 1987
Creator: Yu, S. S.
Object Type: Article
System: The UNT Digital Library
Perturbations of the sun's gravitational field due to solar oscillations (open access)

Perturbations of the sun's gravitational field due to solar oscillations

Considerable evidence has been presented for the detection of low-degree internal gravity modes of the Sun. By combining the observations obtained at the Crimean Astrophysical Observatory and at SCLERA, a number of the modes have been classified with respect to their spatial properties. The number of such modes classified has been extended in a subsequent gravity-mode classification project by Gu and Hill. These mode classifications have been tested using three additional sets of independent observations. Positive results have been obtained in each of these tests. These low-degree modes lead to oscillatory perturbations of the Sun's gravitational field. The amplitudes of these perturbations at the earth are inferred from the observed temperature eigenfunctions. For the l = 2 modes with frequencies near 100..mu..Hz, it is projected that these perturbations in the gravitational field will produce strains of the order of 1.0E-18 in gravitational radiation detectors based on free masses. The signals are expected to have coherence times of hundreds or more years. The detection of these signals by gravitational radiation detectors would make available a new technique for use in solar seismological studies which could be quite useful. The detection of these signals could also serve as a way of monitoring …
Date: October 20, 1987
Creator: Hill, H.A.
Object Type: Article
System: The UNT Digital Library
Neutron Production of Charm Particles in Fermilab E-400 (open access)

Neutron Production of Charm Particles in Fermilab E-400

Results are presented from Fermilab E-400 on the production of charmed baryons and mesons using incident neutrons. We show evidence for the charm-strange baryon, ..xi../sub c//sup +/, and present our measurements of its mass, width, lifetime, cross section and relative branching fractions, and the A, x/sub f/, p/sub t/, and particle/antiparticle dependence of the state. We show evidence for both the ..sigma../sub c//sup + +/ and ..sigma../sub c//sup 0/, and present measurements of three mass differences, ..sigma../sub c//sup + +/ - ..sigma../sub c//sup 0/, ..sigma../sub c//sup 0/ - ..lambda../sub c//sup +/, and ..sigma../sub c//sup + +/ - ..lambda../sub c//sup +/. Preliminary results on the ratio of two decay modes of the D/sup 0/ are shown. D/sup 0/ ..-->.. K/sup +/K/sup -/ and D/sup 0/ ..-->.. K/sub 0/ anti K/sub 0/. The latter mode has not been previously observed. 8 refs., 10 figs.
Date: August 20, 1987
Creator: Cumalat, J. P.; Binkley, M.; Bossi, F.; Butler, J.; Coteus, P.; DiCorato, M. et al.
Object Type: Article
System: The UNT Digital Library
Time-dependent field equations for paraxial relativistic electron beams: Beam Research Program (open access)

Time-dependent field equations for paraxial relativistic electron beams: Beam Research Program

A simplified set of field equations for a paraxial relativistic electron beam is presented. These equations for the beam electrostatic potential phi and pinch potential Phi identical to A/sub z/ - phi retain previously neglected time-dependent terms and for axisymmetric beams reduce exactly to Maxwell's equations.
Date: July 20, 1987
Creator: Sharp, W. M.; Yu, S. S. & Lee, E. P.
Object Type: Report
System: The UNT Digital Library
2, Pulse-mode expansions and refractive indices in plane-wave propagation (open access)

2, Pulse-mode expansions and refractive indices in plane-wave propagation

This memo presents basic background theory for treating simultaneous propagation of electromagnetic pulses of various colors, directed along a common ray, through a molecular vapor. The memo discusses some techniques for expanding the positive frequency part of the transverse electric field into pulse modes, characterized by carrier frequencies within a modulated envelope. We discuss, in the approximation of plane waves with slowly varying envelopes, a set of uncoupled envelope equations in which a polarization mode-envelope acts as a source for an electric-field envelope. These equations, when taken with a prescription for the polarization field, are the basic equations of plane-wave pulse propagation through a molecular medium. We discuss two ways of treating dispersive media, one based upon expansions in the frequency domain and the other based in the time domain. In both cases we find envelope equations that involve group velocities. This memo represents a portion of a more extensive treatment of propagation to be presented separately. Many of the equations presented here have been described in various books and articles. They are collected and described here as a summary and review of contemporary theory.
Date: June 20, 1987
Creator: Shore, B. W.; Sacks, R.; Karr, T.; Morris, J. & Paisner, J. A.
Object Type: Report
System: The UNT Digital Library
The Los Alamos Neutron Scattering Center data acquisition system (open access)

The Los Alamos Neutron Scattering Center data acquisition system

The FASTBUS subsystem of the LANSCE data acquisition system consists of a single FASTBUS crate segment with four custom modules and a QPI interface for the VAX. Since experiments at the LANSCE facility always include a time-of-flight parameter for the detected neutron and may optionally include additional position parameters characterizing the event, a time stamp is generated for each event by the Programmable Master Clock (PMC) module. The time and any position information are latched into the Time-Of-Flight buffer (TOF) module. After all events associated with a single neutron burst have been captured in a frame buffer internal to the TOF module, each event is analyzed by the MAPPER module and reduced to a histogram address to increment in the BULKSTORE module. Software access to the histogram is provided through the QPI interface.
Date: May 20, 1987
Creator: Nelson, R. O.; Cort, G.; Gjovig, A.; Goldstone, J. A.; McMillan, D. E.; Ross, J. et al.
Object Type: Article
System: The UNT Digital Library
Acceleration of polarized protons in AHF (Advanced Hadron Facility) (open access)

Acceleration of polarized protons in AHF (Advanced Hadron Facility)

In this paper an analysis of the depolarization expected during acceleration from 0.8 to 45.0 GeV kinetic energy in the Advanced Hadron Facility (AHF) accelerators is performed.
Date: March 20, 1987
Creator: Colton, E. P.
Object Type: Article
System: The UNT Digital Library
An atmospheric correction algorithm for remote identification of non-Lambertian surfaces and its range of validity (open access)

An atmospheric correction algorithm for remote identification of non-Lambertian surfaces and its range of validity

The usefulness of remotely sensed surface data depends on the ability to correct for atmospheric pertubations on the image. An atmospheric correction algorithm has been proposed which removes atmospheric pertubations from off-nadir measured radiances at the top of the atmosphere in the visible and near-infrared wavelength region. The ability of the model to reproduce radiance distributions at the surface from radiances at the top of the atmosphere is tested and found to be better than 15%. The correction formalism requires as minimum information the total optical depth of the atmosphere and the surface albedo. In this study the accuracy of the model to assumptions about the aerosol phase function, the single-scattering albedo and the vertical profile of the optical depth is also tested.
Date: February 20, 1987
Creator: Gratzki, A. & Gerstl, S.A.W.
Object Type: Article
System: The UNT Digital Library
Modelling of atmospheric effects on the angular distribution of a backscattering peak (open access)

Modelling of atmospheric effects on the angular distribution of a backscattering peak

If off-nadir satellite sensing of vegetative surfaces is considered, understanding the angular distribution of the radiance exiting the atmosphere in all upward directions is of interest. Of particular interest is the discovery of those reflectance features which are invariant to atmospheric perturbations. When mono-directional radiation is incident on a vegetative scene a characteristic angular signature called the hot-spot is produced in the solar retro-direction. The remotely sensed hot-spot is modified by atmospheric extinction of the direct and reflected solar radiation, atmospheric backscattering, and the diffuse sky irradiance incident on the surface. It is demonstrated, however, by radiative transfer calculations through model atmospheres that at least one parameter which characterizes the canopy hot-spot, namely its angular half width, is invariant to atmospheric perturbations. 7 refs., 4 figs., 1 tab.
Date: February 20, 1987
Creator: Powers, B. J. & Gerstl, S. A. W.
Object Type: Article
System: The UNT Digital Library
Active Seismics to Determine Reservoir Characteristics of a Hot Dry Rock Geothermal System (open access)

Active Seismics to Determine Reservoir Characteristics of a Hot Dry Rock Geothermal System

Since 1981 three wells have been drilled to depths of between 2.0 and 2.6 km in the Carnmenellis granite, Cornwall, England in order to create a HDR geothermal system. These wells are separated by between 150 and 300 m and have been hydraulically connected by massive injections of both water and viscous gel (50 cpoise). Passive microseismic monitoring of the hydraulic stimulation and circulation experiments has been used since 1982 to determine the size and structure of the reservoir, and monitor its growth. The active seismic survey techniques of cross-hole seismics and vertical seismic profiling (VSP) have been introduced to complement the passive microseismic monitoring in characterizing the reservoir. The cross-hole seismic surveys indicate that the microseismicity defines the area of joint dilation. The attenuation of high frequencies in the region of microseismicity suggests that the reservoir is composed of a complex zone of cracks rather than a single large fracture. VSP surveys also show a good agreement between the microseismically defined reservoir and seismic signal attenuation. Recent improvements in hardware, computer processing and interpretation indicate that active seismics will play an increasingly important part in mapping and understanding geothermal reservoirs. 11 figs., 10 refs.
Date: January 20, 1987
Creator: Green, A.S.P. & Baria, R.
Object Type: Article
System: The UNT Digital Library
Analysis of Injection-Backflow Tracer Tests in Fractured Geothermal Reservoirs (open access)

Analysis of Injection-Backflow Tracer Tests in Fractured Geothermal Reservoirs

Tracer tests have been an important technique for determining the flow and reservoir characteristics in various rock matrix systems. While the interwell tracer tests are aimed at the characterization of the regions between the wells, single-well injection-backflow tracer tests may be useful tools of preliminary evaluation, before implementing long term interwell tracer tests. This work is concerned with the quantitative evaluation of the tracer return profiles obtained from single well injection-backflow tracer tests. First, two mathematical models of tracer transport through fractures, have been reviewed. These two models are based on two different principles: Taylor Dispersion along the fracture and simultaneous diffusion in and out of the adjacent matrix. Then the governing equations for the transport during the injection-backflow tests have been solved. Finally the results were applied to field data obtained from Raft River and East Mesa geothermal fields. In order to determine the values of the parameters of the models that define the transport mechanisms through fractures a non-linear optimization technique was employed. 26 refs., 10 figs.
Date: January 20, 1987
Creator: Kocabas, I. & Horne, R.N.
Object Type: Article
System: The UNT Digital Library
Analysis of Thermally Induced Permeability Enhancement in Geothermal Injection Wells (open access)

Analysis of Thermally Induced Permeability Enhancement in Geothermal Injection Wells

Reinjection of spent geothermal brine is a common means of disposing of geothermal effluents and maintaining reservoir pressures. Contrary to the predictions of two-fluid models (two-viscosity) of nonisothermal injection, an increase of injectivity, with continued injection, is often observed. Injectivity enhancement and thermally-affected pressure transients are particularly apparent in short-term injection tests at the Los Azufres Geothermal Field, Mexico. During an injection test, it is not uncommon to observe that after an initial pressure increase, the pressure decreases with time. As this typically occurs far below the pressure at which hydraulic fracturing is expected, some other mechanism for increasing the near-bore permeability must explain the observed behavior. This paper focuses on calculating the magnitude of the near-bore permeability changes observed in several nonisothermal injection tests conducted at the Los Azufres Geothermal Field. In order to evaluate the pressure transient data and calculate the magnitude of the thermally induced permeability changes, a new analytic solution for calculating pressure transients with time-varying sandface flowrates and temperatures has been developed. The effects of temperature-dependent fluid and rock properties, as well as a moving thermal front, are explicitly included in the calculations. Based on this new solution, a technique is developed for calculating the …
Date: January 20, 1987
Creator: Benson, S. M.; Daggett, J. S.; Iglesias, E.; Arellano, V. & Ortiz-Ramirez, J.
Object Type: Article
System: The UNT Digital Library
Analysis of Transient Pressure Tests for Olkaria Exploration Wells (open access)

Analysis of Transient Pressure Tests for Olkaria Exploration Wells

Analysis of transient pressure tests for Olkaria West wells shows that both infinite acting and double porosity models can be used to analyze the well behaviour and infer reservoir properties from fall-off steps of long enough duration, in wells where no significant thermal recovery occurs. The double porosity model gives better estimates of reservoir properties than the infinite acting model, for long fall-off steps in wells intercepting fractures. Semilog methods give fairly good estimates of reservoir transmissivity for the long fall-off steps but are highly inaccurate when used independently, especially for the short fall-off steps conducted in most of the wells. Double porosity models can also be used for recovery test analyses where two phase transients are not significant. 6 refs., 11 figs., 8 tabs.
Date: January 20, 1987
Creator: Haukwa, Charles B.
Object Type: Article
System: The UNT Digital Library
Applying Flowrate Type Curves to Geysers Steam Wells (open access)

Applying Flowrate Type Curves to Geysers Steam Wells

Dimensionless flowrate type curves were applied to steam wells at The Geysers in an attempt to quantify reservoir properties and to predict flowrate decline. Although data scatter was a problem, the flowrate data was smoothed by a normalization routine based on the back-pressure equation and the wells were modeled by dimensionless functions for a radial system with a infinite or finite outer boundary and a constant pressure inner boundary (composite analytical-empirical type curve). The “match” resulted in a unique D{sub i} value for use in Arps’ equation and a permeability-thickness product (kh) comparable to kh values obtained from pressure buildup analysis. Finally, it was shown that at least four years of data is required to obtain a unique b value. 2 tabs., 12 refs., 12 figs.
Date: January 20, 1987
Creator: Enedy, Steve
Object Type: Article
System: The UNT Digital Library
Bleeding Characteristics of Geothermal Wells (open access)

Bleeding Characteristics of Geothermal Wells

Abstract: Discharging small flows (order of 1 t/h) from wells is known as bleeding and is to relieve the build-up of gas pressure at the wellhead and to arrest corrosion in the bore. First tests over a range of bleeding flows indicate it as a fruitful subject for study in that temperature and pressure measurements at the wellhead can indicate the well enthalpy and the non-condensible gas content of the production system. Because of environmental restrictions on testing with large discharges in the future, bleeding may soon be the only valid alternative for proving a well’s potential.
Date: January 20, 1987
Creator: James, Russell & Gould, Tom
Object Type: Article
System: The UNT Digital Library
Cerro Prieto Contents of the Technical Information Files Generated at the Field (open access)

Cerro Prieto Contents of the Technical Information Files Generated at the Field

The creation of a computer data bank for the Cerro Prieto Geothermal Field, resulted from the need for fast and flexible management of the increasing and voluminous information generated from the large number of wells drilled in recent years. The data are needed for updating the thermodynamic evolution of the field in order to define field history and validate mathematical analyses applications. This data bank compiles 20 files with all technical information issued from the time of initial field exploration to the end of 1986. To use the data bank, a series of programs and subroutines were created simultaneously for data base management to allow access and add new data as well as data analysis and data graphics. Tables of global statistics of the informations contained in the 20 files are shown in the paper, as an example of one application of the general use of the data base. For particular and specific applications, depending on users’ needs for the data. 3 tabs., 1 fig.
Date: January 20, 1987
Creator: Olmos, Miguel Angel Ayuso
Object Type: Article
System: The UNT Digital Library
Chemical and Isotopic Evidence of Steam Upflow and Partial Condensation in Los Azufres Reservoir (open access)

Chemical and Isotopic Evidence of Steam Upflow and Partial Condensation in Los Azufres Reservoir

Data of chemical and isotopic composition of fluids from Los Azufres wells, collected over a two year period, provide evidence of a process of upward flow and partial condensation of steam in the reservoir, which explains part of the previously reported heterogeneity in isotopic composition of the liquid phase (Nieva et al, 1983). For the southern part of the field, a direct correlation is found between chloride and oxygen-18 concentrations, and an inverse correlation between these parameters and deuterium and carbon dioxide concentrations in the liquid phase of the reservoir. Chloride ion concentrations increase gradually from ca 660 ppm in the production zones of shallow wells to ca 1900 ppm in the case of deep wells. This observation agrees with predictions based on the well-known model for vapor dominated systems of White et al (1971). For the northern part of the field the same correlations are observed, except for the deuterium concentration which in this case correlates directly with oxygen-18. It is concluded that the same process of steam upflow occurs in the northern section but that some other process — perhaps a mixture with other hydrothermal fluid — is also occurring. 3 tabs., 16 refs., 8 figs.
Date: January 20, 1987
Creator: Nieva, D.; Verma, M.; Santoyo, E.; Barragan, R.M.; Portugal, E.; Ortiz, J. et al.
Object Type: Article
System: The UNT Digital Library
Conceptual Model of the Klamath Falls, Oregon Geothermal Area (open access)

Conceptual Model of the Klamath Falls, Oregon Geothermal Area

Over the last 50 years significant amounts of data have been obtained from the Klamath Falls geothermal resource. To date, the complexity of the system has stymied researchers, leading to the development of only very generalized hydrogeologic and geothermal models of the area. Recently, the large quantity of available temperature data have been re-evaluated, revealing new information on subsurface heat flow and locations of faults in the system. These inferences are supported by borehole, geochemical, geophysical, and hydrologic data. Based on re-evaluation of all available data, a detailed conceptual model for the Klamath Falls geothermal resource is proposed. 1 tab., 8 figs., 21 refs.
Date: January 20, 1987
Creator: Prucha, R. H.; Benson, S. M. & Witherspoon, P. A.
Object Type: Article
System: The UNT Digital Library
Decline Curve Analysis of Production Data from the Geysers Geothermal Field (open access)

Decline Curve Analysis of Production Data from the Geysers Geothermal Field

Production data for over two hundred wells at The Geysers geothermal field were compiled and analysed. Decline curves for groups of wells with 5, 10, and 40 acre spacing are presented and compared to curves published previously by Budd (1972) and Dykstra (1981). Decline curves for several individual wells and leases are discussed to illustrate the effects of well spacing and location, as well as the heterogeneous nature of the reservoir. 6 figs., 1 tab., 10 refs.
Date: January 20, 1987
Creator: Ripperda, M. & Bodvarsson, G.S.
Object Type: Article
System: The UNT Digital Library
Development and Exploitation of Low Enthalpy Geothermal Systems, Example of "The Dogger" in the Paris Basin, France (open access)

Development and Exploitation of Low Enthalpy Geothermal Systems, Example of "The Dogger" in the Paris Basin, France

A feature of French geothermal engineering is the development of industrial projects in normal gradient, non-convective areas. The economic feasibility of exploiting wells producing between 150 and 350 m{sup 3}/h at temperatures from 55° to 85° from depths of 1,500 to 2,000 meters, in sedimentary basins with normal gradient, for direct heat production has been proved by 50 plants providing heating for over 500,000 people during the last few years. This opens new possibilities for geothermal energy development the world over, in particular for areas where heat consumption is higher than 2,500 Tons oil equivalent (Toe)/year over several square kilometers. The recent and rapid development of geothermal projects in France, in particular in the Paris Basin has provided much more information on the characteristics of the Jurassic Dogger, which is the unit tapped by geothermal doublets (one production and one injection well). Detailed study of the Dogger reservoir in the Paris Basin is one of the main objectives of the IMRG research and development program drawn up in 1983. The preliminary results presented here are oriented towards (1) improved knowledge of the potential geothermal resources, and (2) analysis of optimum development conditions. 1 tab., 7 refs., 9 figs.
Date: January 20, 1987
Creator: Rojas, J.; Menjoz, A.; Martin, J. C.; Criaud, A. & Fouillac, C.
Object Type: Article
System: The UNT Digital Library
Development Drilling, Testing and Initial Production of the Beowawe Geothermal Field (open access)

Development Drilling, Testing and Initial Production of the Beowawe Geothermal Field

The Beowawe geothermal field in north central Nevada is generating 16MW using two production wells (Ginn 1-13 and 2-13) and one injection well (Batz). Drilling the second production well (Chevron Ginn 2-13) in 1985 led to the discovery of a second productive strand of the Malpais fault zone. The wells are completed in the Malpais fault zone and are capable of producing 420+°F geothermal fluid at rates exceeding 1,000,000 lbs/hr. Initial testing suggests that the completion zones of the two production wells have no pressure communication, therefore providing what is essentially a second production zone for future development. Injection of produced fluids into a fault parallel with the Malpais shows no pressure communication with other wells. One year of production in the system shows no pressure depletion or enthalpy decline in the producing area. 1 tab., 6 figs., 5 refs.
Date: January 20, 1987
Creator: Hoang, V.T.; James, E.D. & Epperson, I.J.
Object Type: Article
System: The UNT Digital Library
Discharging Through an Orifice Determines Steam-Water Enthalpy (open access)

Discharging Through an Orifice Determines Steam-Water Enthalpy

Abstract: A wide range of steam-water mixtures was discharged to the atmosphere through a 10.7 mm diameter orifice which was sharp-edged with a minuscule throat pressure tapping. The ratio of throat pressure to up-stream pressure was found sensitive to dryness fraction over the whole range studied from 0.03 to 1.0. The technique (employing large orifices) has the potential of identifying the unknown enthalpy of geothermal wells discharging large flows. Contrariwise, a nozzle (rounded entry orifice) was found remarkably _insensitive_ over most of the dryness range and hence is useless for such determinations; however, it can be used to measure the flow-rate when enthalpy is known.
Date: January 20, 1987
Creator: James, Russell
Object Type: Article
System: The UNT Digital Library