Pacific Northwest and Alaska Regional Bioenergy Program : Five Year Report, 1985-1990. (open access)

Pacific Northwest and Alaska Regional Bioenergy Program : Five Year Report, 1985-1990.

This five-year report describes activities of the Pacific Northwest and Alaska Regional Bioenergy Program between 1985 and 1990. Begun in 1979, this Regional Bioenergy Program became the model for the nation's four other regional bioenergy programs in 1983. Within the time span of this report, the Pacific Northwest and Alaska Regional Bioenergy Program has undertaken a number of applied research and technology projects, and supported and guided the work of its five participating state energy programs. During this period, the Regional Bioenergy Program has brought together public- and private-sector organizations to promote the use of local biomass and municipal-waste energy resources and technologies. This report claims information on the mission, goals and accomplishments of the Regional Bioenergy Program. It describes the biomass projects conducted by the individual states of the region, and summarizes the results of the programs technical studies. Publications from both the state and regional projects are listed. The report goes on to consider future efforts of the Regional Bioenergy Program under its challenging assignment. Research activities include: forest residue estimates; Landsat biomass mapping; woody biomass plantations; industrial wood-fuel market; residential space heating with wood; materials recovery of residues; co-firing wood chips with coal; biomass fuel characterization; wood-boosted …
Date: February 1, 1991
Creator: (U.S.), Pacific Northwest and Alaska Bioenergy Program
Object Type: Report
System: The UNT Digital Library
Overview of Low-Level Waste Disposal Operations at the Nevada Test Site (open access)

Overview of Low-Level Waste Disposal Operations at the Nevada Test Site

The U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office Environmental Management Program is charged with the responsibility to carry out the disposal of on-site and off-site generated low-level radioactive waste at the Nevada Test Site. Core elements of this mission are ensuring that disposal take place in a manner that is safe and cost-effective while protecting workers, the public, and the environment. This paper focuses on giving an overview of the Nevada Test Site facilities regarding currant design of disposal. In addition, technical attributes of the facilities established through the site characterization process will be further described. An update on current waste disposal volumes and capabilities will also be provided. This discussion leads to anticipated volume projections and disposal site requirements as the Nevada Test Site disposal operations look towards the future.
Date: February 1, 2007
Creator: /Navarro, DOE
Object Type: Article
System: The UNT Digital Library
The Changing Adventures of Mixed Low-Level Waste Disposal at the Nevada Test Site (open access)

The Changing Adventures of Mixed Low-Level Waste Disposal at the Nevada Test Site

After a 15-year hiatus, the United States Department of Energy (DOE) National Nuclear Security Administration Nevada Site Office (NNSA/NSO) began accepting DOE off-site generated mixed low-level radioactive waste (MLLW) for disposal at the Nevada Test Site (NTS) in December 2005. This action was predicated on the acceptance by the Nevada Division of Environmental Protection (NDEP) of a waste analysis plan (WAP). The NNSA/NSO agreed to limit mixed waste disposal to 20,000 cubic meters (approximately 706,000 cubic feet) and close the facility by December 2010 or sooner, if the volume limit is reached. The WAP and implementing procedures were developed based on Hanford’s system of verification to the extent possible so the two regional disposal sites could have similar processes. Since the NNSA/NSO does not have a breaching facility to allow the opening of boxes at the site, verification of the waste occurs by visual inspection at the generator/treatment facility or by Real-Time-Radiography (RTR) at the NTS. This system allows the NTS to effectively, efficiently, and compliantly accept MLLW for disposal. The WAP, NTS Waste Acceptance Criteria, and procedures have been revised based on learning experiences. These changes include: RTR expectations; visual inspection techniques; tamper-indicating device selection; void space requirements; and …
Date: February 1, 2007
Creator: /Navarro/NSTec, DOE
Object Type: Article
System: The UNT Digital Library
Generalization of the ERIT Principle and Method (open access)

Generalization of the ERIT Principle and Method

N/A
Date: February 1, 2008
Creator: A., Ruggiero
Object Type: Report
System: The UNT Digital Library
A Super-Conducting Linac as a new Injector to the BNL-AGS (open access)

A Super-Conducting Linac as a new Injector to the BNL-AGS

N/A
Date: February 1, 2001
Creator: A., Ruggiero
Object Type: Report
System: The UNT Digital Library
Tracking of Acceleration with HNJ Method (open access)

Tracking of Acceleration with HNJ Method

N/A
Date: February 1, 2008
Creator: A., Ruggiero
Object Type: Report
System: The UNT Digital Library
Comparison of the present and planned operation of the SIS18 and the AGS Booster with intermediate charge state heavy ions (open access)

Comparison of the present and planned operation of the SIS18 and the AGS Booster with intermediate charge state heavy ions

N/A
Date: February 1, 2006
Creator: A., Smolyakov; Fischer, W.; Omet, C. & Spiller, P.
Object Type: Report
System: The UNT Digital Library
Confinement of airborne radioactivity. Final progress report, January-December 1978 (open access)

Confinement of airborne radioactivity. Final progress report, January-December 1978

A new test method has been developed at the Savannah River Laboratory for evaluating the iodine retention capabilities of carbon used in the airborne-activity confinement system. Methyl iodide tagged with I-131 is injected into a test gas stream continuously for 5 hours with test conditions of 80/sup 0/C temperature, 95% relative humidity, and 55 feet per minute linear flow velocity. Results show that the CH/sub 3/I retention efficiency is independent of the inlet CH/sub 3/I concentration over the range of at least 0.9 to 200 ..mu..g/m/sup 3/ in the test gas stream. The method was also used to evaluate the effects of paint fumes on in-service carbons and showed that solvent exposure reduced carbon service life by 5 to 7 months. Experimental carbons both before and after service exposure in the SRP carbon test facility were also evaluated.
Date: February 1, 1980
Creator: A.G., Evans
Object Type: Report
System: The UNT Digital Library
Integrated Microsensors for Autonomous Microrobots (open access)

Integrated Microsensors for Autonomous Microrobots

This report describes the development of a miniature mobile microrobot device and several microsystems needed to create a miniature microsensor delivery platform. This work was funded under LDRD No.10785, entitled, ''Integrated Microsensors for Autonomous Microrobots''. The approach adopted in this project was to develop a mobile platform, to which would be attached wireless RF remote control and data acquisition in addition to various microsensors. A modular approach was used to produce a versatile microrobot platform and reduce power consumption and physical size.
Date: February 1, 2003
Creator: ADKINS, DOUGLAS R.; BYRNE, RAYMOND H.; HELLER, EDWIN J. & WOLF, JIMMIE V.
Object Type: Report
System: The UNT Digital Library
RESEARCH PLAN FOR SPIN PHYSICS AT RHIC. (open access)

RESEARCH PLAN FOR SPIN PHYSICS AT RHIC.

In this report we present the research plan for the RHIC spin program. The report covers (1) the science of the RHIC spin program in a world-wide context; (2) the collider performance requirements for the RHIC spin program; (3) the detector upgrades required, including timelines; (4) time evolution of the spin program.
Date: February 1, 2005
Creator: AIDALA, C.; BUNCE, G. & AL., ET
Object Type: Report
System: The UNT Digital Library
Search for New Heavy Particles Decaying to Z0 Z0 to llll, lljj in p pbar Collisions at Sqrt(s) = 1.96 TeV (open access)

Search for New Heavy Particles Decaying to Z0 Z0 to llll, lljj in p pbar Collisions at Sqrt(s) = 1.96 TeV

We report on a search for anomalous production of Z pairs through a massive resonance decay in data corresponding to 2.5-2.9 fb{sup -1} of integrated luminosity in p{bar p} collisions at {radical}s = 1.96 TeV using the CDF II detector at the Fermilab Tevatron. This analysis, with more data and channels where the Z bosons decay to muons or jets, supersedes the 1.1 fb{sup -1} four-electron channel result previously published by CDF. In order to maintain high efficiency for muons, we use a new forward tracking algorithm and muon identification requirements optimized for these high signal-to-background channels. Predicting the dominant backgrounds in each channel entirely from sideband data samples, we observe four-body invariant mass spectra above 300 GeV/c{sup 2} that are consistent with background. We set limits using the acceptance for a massive graviton resonance that are 7-20 times stronger than the previously published direct limits on resonant ZZ production.
Date: February 1, 2011
Creator: Aaltonen, T.
Object Type: Article
System: The UNT Digital Library
Combination of CDF and D0 measurements of the $W$ boson helicity in top quark decays (open access)

Combination of CDF and D0 measurements of the $W$ boson helicity in top quark decays

We report the combination of recent measurements of the helicity of the W boson from top quark decay by the CDF and D0 collaborations, based on data samples corresponding to integrated luminosities of 2.7-5.4 fb{sup -1} of p{bar p} collisions collected during Run II of the Fermilab Tevatron Collider. Combining measurements that simultaneously determine the fractions of W bosons with longitudinal (f{sub 0}) and right-handed (f{sub +}) helicities, we find f{sub 0} = 0.722 {+-} 0.081 [{+-} 0.062 (stat.) {+-} 0.052 (syst.)] and f{sub +} = -0.033 {+-} 0.046 [{+-} 0.034 (stat.) {+-} 0.031 (syst.)]. Combining measurements where one of the helicity fractions is fixed to the value expected in the standard model, we find f{sub 0} = 0.682 {+-} 0.057 [{+-} 0.035 (stat.) {+-} 0.046 (syst.)] and f{sub +} = ?0.015 {+-} 0.035 [{+-} 0.018 (stat.) {+-} 0.030 (syst.)]. The results are consistent with standard model expectations.
Date: February 1, 2012
Creator: Aaltonen, T.; Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Object Type: Article
System: The UNT Digital Library
Observation of exclusive charmonium production and gamma gamma ---> mu+mu- in p anti-p collisions at s**(1/2) = 1.96-TeV (open access)

Observation of exclusive charmonium production and gamma gamma ---> mu+mu- in p anti-p collisions at s**(1/2) = 1.96-TeV

We have observed the reactions p + {bar p} {yields} p + X + {bar p}, with X being a centrally produced J/{psi}, {psi}(2S) or {chi}{sub c0}, and {gamma}{gamma} {yields} {mu}{sup +}{mu}{sup -}, in proton-antiproton collisions at {radical}s = 1.96 TeV using the Run II Collider Detector at Fermilab. The event signature requires two oppositely charged muons, each with pseudorapidity |{eta}| < 0.6, with M{sub {mu}{mu}} {element_of} [3.0; 4.0] GeV/c{sup 2} and either no other particles, or one additional photon, detected. The J/{psi} and the {psi}(2S) are prominent, on a continuum consistent with the QED process {gamma}{gamma} {yields} {mu}{sup +}{mu}{sup -}. Events with a J/{psi} and an associated photon candidate are consistent with exclusive {chi}{sub c0} production through double pomeron exchange. The exclusive vector meson production is as expected for elastic photoproduction, {gamma} + p {yields} J/{psi}({psi}(2S)) + p, which is observed here for the first time in hadron-hadron collisions. The cross sections d{sigma}/dy|y = 0 for p + {bar p} {yields} p + X + {bar p} with X = J/{psi},{psi}(2S) or {chi}{sub c0} are 3.92 {+-} 0.62 nb, 0.53 {+-} 0.14 nb, and 76 {+-} 14 nb respectively. The cross section for the continuum, with |{eta}({mu}{sup {+-}})| < …
Date: February 1, 2009
Creator: Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, M. G.; Alvarez Gonzalez, B.; Amerio, S. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt(s)=1.96 TeV using Soft Electron b-Tagging (open access)

Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt(s)=1.96 TeV using Soft Electron b-Tagging

We present a measurement of the top quark pair production cross section in p{bar p} collisions at {radical}s = 1.96 TeV using a data sample corresponding to 1.7 fb{sup -1} of integrated luminosity collected with the Collider Detector at Fermilab. We reconstruct t{bar t} events in the lepton+jets channel, consisting of e{nu}+jets and {mu}{nu}+jets final states. The dominant background is the production of W bosons in association with multiple jets. To suppress this background, we identify electrons from the semileptonic decay of heavy-flavor jets ('soft electron tags'). From a sample of 2196 candidate events, we obtain 120 tagged events with a background expectation of 51 {+-} 3 events, corresponding to a cross section of {sigma}{sub t{bar t}} = 7.8 {+-} 2.4 (stat) {+-} 1.6 (syst) {+-} 0.5 (lumi) pb. We assume a top-quark mass of 175 GeV/c{sup 2}. This is the first measurement of the t{bar t} cross section with soft electron tags in Run II of the Tevatron.
Date: February 1, 2010
Creator: Aaltonen, T.; Adelman, J.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the $WZ$ Cross Section and Triple Gauge Couplings in $p \bar p$ Collisions at $\sqrt{s} = 1.96$ TeV (open access)

Measurement of the $WZ$ Cross Section and Triple Gauge Couplings in $p \bar p$ Collisions at $\sqrt{s} = 1.96$ TeV

This Letter describes the current most precise measurement of the WZ production cross section as well as limits on anomalous WWZ couplings at a center-of-mass energy of 1.96 TeV in proton-antiproton collisions. The WZ candidates are reconstructed from decays containing three charged leptons and missing energy from a neutrino, where the charged leptons are either electrons or muons. Using data collected by the CDF II detector (7.1 fb{sup -1} of integrated luminosity), 64 candidate events are observed with the expected background contributing 8 {+-} 1 events. The measured total cross section {sigma}(p{bar p} {yields} WZ) = 3.93{sub -0.53}{sup +0.60}(stat){sub -0.46}{sup +0.59}(syst) pb is in good agreement with the standard model prediction of 3.50 {+-} 0.21. The same sample is used to set limits on anomalous WWZ couplings.
Date: February 1, 2012
Creator: Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A. et al.
Object Type: Article
System: The UNT Digital Library
Search for a dark matter candidate produced in association with a single top quark in $p\bar{p}$ collisions at $\sqrt{s} = 1.96$ TeV (open access)

Search for a dark matter candidate produced in association with a single top quark in $p\bar{p}$ collisions at $\sqrt{s} = 1.96$ TeV

We report a new search for dark matter in a data sample of an integrated luminosity of 7.7 fb{sup -1} of Tevatron p{bar p} collisions at {radical}s = 1.96 TeV, collected by the CDF II detector. We search for production of a dark matter candidate, D, in association with a single top quark. We consider the hadronic decay mode of the top quark exclusively, yielding a final state of three jets with missing transverse energy. The data are consistent with the standard model; we thus set 95% confidence level upper limits on the cross section of the process p{bar p} {yields} t + D as a function of the mass of the dark-matter candidate. The limits are approximately 0.5 pb for a dark-matter particle with mass in the range of 0 - 150 GeV/c{sup 2}.
Date: February 1, 2012
Creator: Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A. et al.
Object Type: Article
System: The UNT Digital Library
Search for Anomalous Production of Multiple Leptons in Association With $W$ and $Z$ Bosons at Cdf (open access)

Search for Anomalous Production of Multiple Leptons in Association With $W$ and $Z$ Bosons at Cdf

This paper presents a search for anomalous production of multiple low-energy leptons in association with a W or Z boson using events collected at the CDF experiment corresponding to 5.1 fb{sup -1} of integrated luminosity. This search is sensitive to a wide range of topologies with low-momentum leptons, including those with the leptons near one another. The observed rates of production of additional electrons and muons are compared with the standard model predictions. No indications of phenomena beyond the standard model are found. A 95% confidence level limit is presented on the production cross section for a benchmark model of supersymmetric hidden-valley Higgs production. Particle identification efficiencies are also provided to enable the calculation of limits on additional models.
Date: February 1, 2012
Creator: Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A. et al.
Object Type: Article
System: The UNT Digital Library
Search for exclusive Z boson production and observation of high mass p anti-p ---> gamma gamma anti-p ---> pl+ l- anti-p events in p anti-p collisions at s**(1/2) = 1.96-TeV (open access)

Search for exclusive Z boson production and observation of high mass p anti-p ---> gamma gamma anti-p ---> pl+ l- anti-p events in p anti-p collisions at s**(1/2) = 1.96-TeV

We present a search for exclusive Z boson production in proton-antiproton collisions at {radical}s = 1.96 TeV, using the CDF II detector at Fermilab. We observe no exclusive Z {yields} {ell}{sup +}{ell}{sup -} candidates and place the first upper limit on the exclusive Z cross section in hadron collisions, {sigma}{sub excl}(Z) < 0.96 pb at 95% confidence level. In addition, we observe eight candidate exclusive dilepton events from the quantum electrodynamic process p{bar p} {yields} p{gamma}{gamma}{bar p} {yields} p{ell}{sup +}{ell}{sup -} {bar p}, and measure the cross section for M{sub {ell}{ell}} > 40 GeV=c{sup 2} and |{eta}{sub {ell}}| < 4 to be {sigma} = 0.24{sub -0.10}{sup +0.13} pb, which is the first measurement for this mass range and is consistent with the standard model prediction.
Date: February 1, 2009
Creator: Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Akimoto, T.; U., /Tsukuba et al.
Object Type: Article
System: The UNT Digital Library
Search for the Higgs boson in events with missing transverse energy and b quark jets produced in proton-antiproton collisions at s**(1/2)=1.96 TeV (open access)

Search for the Higgs boson in events with missing transverse energy and b quark jets produced in proton-antiproton collisions at s**(1/2)=1.96 TeV

We search for the standard model Higgs boson produced in association with an electroweak vector boson in events with no identified charged leptons, large imbalance in transverse momentum, and two jets where at least one contains a secondary vertex consistent with the decay of b hadrons. We use {approx}1 fb{sup -1} integrated luminosity of p{bar p} collisions at {radical}s = 1.96 TeV recorded by the CDF II experiment at the Tevatron. We find 268 (16) single (double) b-tagged candidate events, where 248 {+-} 43 (14.4 {+-} 2.7) are expected from standard model background processes. We place 95% confidence level upper limits on the Higgs boson production cross section for several Higgs boson masses ranging from 110 GeV/c{sup 2} to 140 GeV/c{sup 2}. For a mass of 115 GeV/c{sup 2} the observed (expected) limit is 20.4 (14.2) times the standard model prediction.
Date: February 1, 2008
Creator: Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Akimoto, T.; U., /Tsukuba et al.
Object Type: Article
System: The UNT Digital Library
Search for the Production of Narrow t anti-b Resonances in 1.9 fb-1 of p anti-p Collisions at s**(1/2) = 1.96-TeV (open access)

Search for the Production of Narrow t anti-b Resonances in 1.9 fb-1 of p anti-p Collisions at s**(1/2) = 1.96-TeV

We present new limits on resonant tb production in ppbar collisions at sqrt(s) = 1.96 TeV, using 1.9 fb{sup -1} of data recorded with the CDF II detector at the Fermilab Tevatron. We reconstruct a putative tb mass in events with a lepton, neutrino candidate, and two or three jets, and search for anomalous tb production as modeled by W{prime} {yields} tb. We set a new limit on a right-handed W{prime} with standard model-like coupling, excluding any mass below 800 GeV at 95% C.L. For any narrow W{prime}-like state with mass above 800 GeV, the cross-section is found to be less than 0.28 pb at 95% C.L. We also present an exclusion of the W{prime} coupling strength versus W{prime} mass.
Date: February 1, 2009
Creator: Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Akimoto, T.; U., /Tsukuba et al.
Object Type: Article
System: The UNT Digital Library
Two-Particle Momentum Correlations in Jets Produced in p antip Collisions at s**(1/2) = 1.96-TeV (open access)

Two-Particle Momentum Correlations in Jets Produced in p antip Collisions at s**(1/2) = 1.96-TeV

None
Date: February 1, 2008
Creator: Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Akimoto, T.; U., /Tsukuba et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the Top Quark Mass and ppbar -> ttbar Cross Section in the All-Hadronic Mode with the CDFII Detector (open access)

Measurement of the Top Quark Mass and ppbar -> ttbar Cross Section in the All-Hadronic Mode with the CDFII Detector

We present a measurement of the top quark mass and of the top-antitop pair production cross section using p{bar p} data collected with the CDF II detector at the Tevatron Collider at the Fermi National Accelerator Laboratory and corresponding to an integrated luminosity of 2.9 fb{sup -1}. We select events with six or more jets satisfying a number of kinematical requirements imposed by means of a neural network algorithm. At least one of these jets must originate from a b quark, as identified by the reconstruction of a secondary vertex inside the jet. The mass measurement is based on a likelihood fit incorporating reconstructed mass distributions representative of signal and background, where the absolute jet energy scale (JES) is measured simultaneously with the top quark mass. The measurement yields a value of 174.8 {+-} 2.4(stat+JES){sub -1.0}{sup +1.2}(syst)GeV/c{sup 2}, where the uncertainty from the absolute jet energy scale is evaluated together with the statistical uncertainty. The procedure measures also the amount of signal from which we derive a cross section, {sigma}{sub t{bar t}} = 7.2 {+-} 0.5(stat) {+-} 1.0(syst) {+-} 0.4(lum) pb, for the measured values of top quark mass and JES.
Date: February 1, 2010
Creator: Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Alvarez Gonzalez, B.; Phys., /Cantabria Inst. of et al.
Object Type: Article
System: The UNT Digital Library
Observation of $B^0_s \to J/\psi K^{*0}(892)$ and $B^0_s \to J/\psi K^0_S$ Decays (open access)

Observation of $B^0_s \to J/\psi K^{*0}(892)$ and $B^0_s \to J/\psi K^0_S$ Decays

The authors report the first observation of two Cabibbo-suppressed decay modes of the B{sub s}{sup 0} meson. Using a sample of p{bar p} collisions at {radical}s = 1.96 TeV corresponding to 5.9 fb{sup -1} of integrated luminosity collected with the CDF II detector at the Fermilab Tevatron, they search for new B{sub s}{sup 0} decay modes in a sample of events containing J/{psi} {yields} {mu}{sup +}{mu}{sup -} decays. They reconstruct a B{sub s}{sup 0} {yields} J/{psi} K*(892){sup 0} signal with K*(892){sup 0} {yields} K{sup +}{pi}{sup -}, observing a yield of 151 {+-} 25 events with a statistical significance of 8.0{sigma}. They also reconstruct a B{sub s}{sup 0} {yields} J/{psi} K{sub S}{sup 0} signal with K{sub S}{sup 0} {yields} {pi}{sup +}{pi}{sup -}, observing a yield of 64 {+-} 14 events with a statistical significance of 7.2{sigma}. From these yields, they extract the branching ratios {Beta}(B{sub s}{sup 0} {yields} J/{psi} K*(892){sup 0}) = (8.3 {+-} 3.8) x 10{sup -5} and {Beta}(B{sub s}{sup 0} {yields} J/{psi} K{sup 0}) = (3.5 {+-} 0.8) x 10{sup -5}, where statistical, systematic, and fragmentation-fraction uncertainties are included in the combined uncertainty.
Date: February 1, 2011
Creator: Aaltonen, T.; Phys., /Helsinki Inst. of; Alvarez Gonzalez, B.; Phys., /Cantabria Inst. of; Amerio, S.; /INFN, Padua et al.
Object Type: Article
System: The UNT Digital Library
Hydraulic fracture experiments in GT-1 and GT-2 (open access)

Hydraulic fracture experiments in GT-1 and GT-2

Hydraulic fracturing experiments were conducted in granite rock, at temperatures near 100 and 150/sup 0/C, in two wells 0.785 km (2575 ft) and 1.98 km (6500 ft) deep near Los Alamos, New Mexico. No unusual difficulty was observed in fracturing crystalline rock hydraulically. The apparent surface energy (energy required to create new fracture surface by breaking the rock) was measured as 100 J/m/sup 2/. Orientation of the deeper fracture was measured as N35/sup 0/E (+-5/sup 0/). The fraction of fluid injected into the rock that could be recovered at hydrostatic surface pressure was measured. The efficiency of recovery was as high as 92 percent after the fracture impedance was lowered by ''propping'' the fracture with sand. Permeability of the rock over the face of the fracture was compatible with laboratory measurements (10/sup -7/ to 10/sup -8/ darcys). Downhole pressures required to extend the fractures were about 150 and 340 bars (2175 and 4900 psi), respectively.
Date: February 1, 1977
Creator: Aamodt, R. L.
Object Type: Report
System: The UNT Digital Library