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At least 1,657 records · Page 92

A simple model of gas flow in a porous powder compact

This report describes a simple model for ideal gas flow from a vessel through a bed of porous material into another vessel. It assumes constant temperature and uniform porosity. Transport is treated as a combination of viscous and molecular flow, with no inertial contribution (low Reynolds number). This model can be used to fit data to obtain permeability values, determine flow rates, understand the relative contributions of viscous and molecular flow, and verify volume calibrations. It draws upon the Dusty Gas Model and other detailed studies of gas flow through porous media.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Development and Deployment of a Compact Eye-Safe Scanning Differential absorption Lidar (DIAL) for Spatial Mapping of Carbon Dioxide for Monitoring/Verification/Accounting at Geologic Sequestration Sites

A scanning differential absorption lidar (DIAL) instrument for monitoring carbon dioxide has been developed. The laser transmitter uses two tunable discrete mode laser diodes (DMLD) operating in the continuous wave (cw) mode with one locked to the online absorption wavelength and the other operating at the offline wavelength. Two in-line fiber optic switches are used to switch between online and offline operation. After the fiber optic switch, an acousto- optic modulator (AOM) is used to generate a pulse train used to injection seed an erbium doped fiber amplifier (EDFA) to produce eye-safe laser pulses with maximum pulse energies of 66 {micro}J, a pulse repetition frequency of 15 kHz, and an operating wavelength of 1.571 {micro}m. The DIAL receiver uses a 28 cm diameter Schmidt-Cassegrain telescope to collect that backscattered light, which is then monitored using a photo-multiplier tube (PMT) module operating in the photon counting mode. The DIAL instrument has been operated from a laboratory environment on the campus of Montana State University, at the Zero Emission Research Technology (ZERT) field site located in the agricultural research area on the western end of the Montana State University campus, and at the Big Sky Carbon Sequestration Partnership site located in north-central Montana. DIAL data has been collected and profiles have been validated using a co-located Licor LI-820 Gas Analyzer point sensor.

47 OTHER INSTRUMENTATION↗

Measurement of the Forward-Backward Asymmetry in $\gamma/Z$ boson to Dilepton Events in Compact Muon Solenoid at a Center-of-mass Energy of 7 TeV

The forward-backward asymmetry parameter (AFB) as a function of dilepton invariant mass in Z/γ* →l + l - (l=e or μ) at √s=7 TeV is measured using 2.2 fb -1 of pp collision data in 2011. The forward-backward asymmetry measurement is performed using muons within |η| < 2.1 and electrons within |η| < 2.4 in a wide mass range between 40 GeV/c 2 to 1000 GeV/c 2 . The forward-backward asymmetry is also measured for the first time in a large rapidity range of |η| < 5 with electrons using the CMS forward calorimeters and results in a less diluted A FB measurement, as expected. The forward-backward asymmetry parameters are unfolded in three stages, limited pre-FSR, full pre-FSR, and non-diluted stage in order to obtain parton level A FB . The muon and electron results are combined, and the individual and combined results are found to be consistent with the Standard Model prediction within statistical and systematic uncertainties.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Compact, Inexpensive Micro-Reformer for Distributed GTL Systems (Final Scientific/Technical Report)

This award allowed MIT Plasma Science and Fusion Center, in collaboration with the Departments of Chemical and Mechanical Engineering, to demonstrate the feasibility of using an engine as the reformer for a gas-to-liquids plants. Engine reformation in cylinder has been used in the past for limited production of hydrogen rich gas. However, the performance was limited, and for syngas generation as part of a chemical plant, the output was inadequate. The focus of the ARPA-E seed project was to demonstrate, in oxygen or in air, the production of hydrogen rich gas with good conversion and selectivity. The goal was equivalence ratios ~ 3 in oxygen, or highly enriched air. The accomplishment performance was equivalence ratios ~ 2 with air.

03 NATURAL GAS↗

Compaction Behavior of Surrogate Degraded Emplaced WIPP Waste

The present study results are focused on laboratory testing of surrogate waste materials. The surrogate wastes correspond to a conservative estimate of degraded Waste Isolation Pilot Plant (WIPP) containers and TRU waste materials at the end of the 10,000 year regulatory period. Testing consists of hydrostatic, triaxial, and uniaxial strain tests performed on surrogate waste recipes that were previously developed by Hansen et al. (1997). These recipes can be divided into materials that simulate 50% and 100% degraded waste by weight. The percent degradation indicates the anticipated amount of iron corrosion, as well as the decomposition of cellulosics, plastics, and rubbers (CPR). Axial, lateral, and volumetric strain and axial, lateral, and pore stress measurements were made. Two unique testing techniques were developed during the course of the experimental program. The first involves the use of dilatometry to measure sample volumetric strain under a hydrostatic condition. Bulk moduli of the samples measured using this technique were consistent with those measured using more conventional methods. The second technique involved performing triaxial tests under lateral strain control. By limiting the lateral strain to zero by controlling the applied confining pressure while loading the specimen axially in compression, one can maintain a right-circular cylindrical geometry even under large deformations. This technique is preferred over standard triaxial testing methods which result in inhomogeneous deformation or “barreling”. Manifestations of the inhomogeneous deformation included non-uniform stress states, as well as unrealistic Poisson’s ratios (> 0.5) or those that vary significantly along the length of the specimen. Zero lateral strain controlled tests yield a more uniform stress state, and admissible and uniform values of Poisson’s ratio.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

C2R2: Compact Compound Recirculator/Recuperator for Renewable Energy and Energy Efficient Thermochemical Processing

In this report we present the development of a packed particle bed recirculator and heat exchanger. The device is intended to create countercurrent flows of packed particle beds and exchange heat between the flows. The project focused on the design, fabrication, demonstration, and modifications of a simple prototype, in order to attain high levels of heat exchange between particle flows while maintaining an effective particle conveying rate in a scalable package. Despite heat losses in a package not optimized for heat retention, 50% heat recovery was achieved, at a particle conveying efficiency of 40%.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

High Accuracy Transistor Compact Model Calibrations

Typically, transistors are modeled by the application of calibrated nominal and range models. These models consists of differing parameter values that describe the location and the upper and lower limits of a distribution of some transistor characteristic such as current capacity. Correspondingly, when using this approach, high degrees of accuracy of the transistor models are not expected since the set of models is a surrogate for a statistical description of the devices. The use of these types of models describes expected performances considering the extremes of process or transistor deviations. In contrast, circuits that have very stringent accuracy requirements require modeling techniques with higher accuracy. Since these accurate models have low error in transistor descriptions, these models can be used to describe part to part variations as well as an accurate description of a single circuit instance. Thus, models that meet these stipulations also enable the calculation of quantification of margins with respect to a functional threshold and uncertainties in these margins. Given this need, new model high accuracy calibration techniques for bipolar junction transistors have been developed and are described in this report.

42 ENGINEERING↗

A Compact, Broad-Band Hyperspectral SpectroRadiometer (Final Report)

The Phase I effort has laid the foundation for developing a complete, high-performance hyperspectral imaging system based on a patented approach. Detailed optical modeling has been performed to identify an optimal design that promises excellent imaging, low stray-light, and large signal-to-noise ratios across the full spectral range of 350-2500 nm. Vibration analysis indicates the instrument’s primary optics will be stable when deployed in high-vibration environments such as onboard a UAV, and a mechanical design has been developed. A two-step development plan has been formulated to minimize risk. In the first step, a deployable prototype instrument will be built that provides full performance but will utilize a somewhat heavy, but proven, data acquisition system. This will leave sufficient time and resources to address problems that may arise and incorporate a more advanced data acquisition system during the second step, plus leave time and resources to make other improvements identified during testing done during the first step. In summary, the effort will lead to an advanced instrument for vegetation monitoring, which may find applications in agriculture, pipeline monitoring, and it will find applications for a broad range of research including work devoted to understanding of the carbon cycle.

54 ENVIRONMENTAL SCIENCES↗

Compact Ultraintense Femtosecond Laser via Raman Amplifier and Compressor in Plasma

The main objective of this project was to conduct experimental and theoretical research to find conditions leading to higher, than previously obtained efficiency η of transfer the pump energy into the short seed beam in plasma of Stimulated Raman Back-Scattering (SRBS). We have demonstrated very large amplification and compression in our earlier SRBS plasma. However, the efficiency η was much too low to reach very high intensity of the output beam in the focal spot. Recently, by solving a very difficult technical SRBS’ problem, namely, the creation of very reproducible and much larger diameter plasma channels than in our earlier research, we propose a new approach to obtain higher efficiency η. The crucial new result was a very reproducible, low noise amplified seed in the larger diameter of the plasma channel leading to the higher efficiency. Using this new setup and very encouraging results about increase efficiency continuing this approach in the future the efficiency is expect to reach the range of η ≈15 - 20 % required to develop practical SRBS plasma laser. Intellectual Merit: The model for the present project was created by our earlier SRBS experiments. The main objective of those experiments was to amplify and compress the seed pulses in a plasma . The experiments demonstrated an unprecedented large pulse intensity amplification of 20,000 in system of 2-passes in ~2mm long plasma, and the seed pulse compression from 550fsec down to ~50fsec. The pump and seed beams in the present project have diameters of ~0.2–0.25mm each, propagating in ~0.35 - 0.45mm diameter and ~2-2.5mm long plasma channels (optimal length for our SRBS experiment) with input pump and seed intensities of 2x1014 and 3x1013 W/cm2, respectively. Such an SRBS system design was “prescribed” by computer simulations, which predict elimination of the SRBS “ saturation” for a such relatively short plasma channel. Plasma channels has been created by combining shorter (200psec) and longer (5nsec) laser pulses using an axicon lens for shorter pulse and spherical lens for longer pulse, a unique procedure we have developed for SRBS experiments.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Measurement of the Forward-Backward Asymmetry in $\gamma/Z$ boson to Dilepton Events in Compact Muon Solenoid at a Center-of-mass Energy of 7 TeV

The forward-backward asymmetry parameter ($A_{\rm FB}$) as a function of dilepton invariant mass in $Z / \gamma^* \rightarrow l^+l^-$ ($l$=$e$ or $\mu$) at $\sqrt{s}$=7 TeV is measured using 2.2 fb$^{-1}$ of $pp$ collision data in 2011. The uncorrected (raw) $A_{\rm FB}$ and the corrected (unfolded) $A_{\rm FB}$ is performed in a wide mass range between 40 GeV/$c^{2}$ to 1000 GeV/$c^{2}$, and comparative studies and correction techniques with simulation are described in detail. We measure raw $A_{\rm FB}$ for the first time in a large rapidity range of 3 $<|\eta| <$ 5 with electrons using the forward calorimeters and achieve almost non-diluted $A_{\rm FB}$ result. The $A_{\rm FB}$ measurements with muons and electrons and their combination are consistent with the Standard Model (SM) prediction within uncertainties.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

A Search for WW$\gamma$ and WZ$\gamma$ Triboson Production and Anomalous Quartic Gauge Couplings at $\sqrt{s}$ = 8 and 13~TeV within the Compact Muon Solenoid

An analysis probing for the standard model production of three electroweak vector bosons, WV$\gamma$ with V = W or Z gauge boson, is presented. The W boson decays leptonically to an electron or muon, or their respective antiparticle, paired with the appropriate neutrino. The second boson V decays hadronically into two jets, and additionally a photon is required in the event. The data analyzed correspond to an integrated luminosity of 19.6~fb$^{-1}$ and 2.3~fb$^{-1}$ from proton-proton collisions at $\sqrt{s}$ = 8~TeV and 13~TeV, respectively, collected in 2012 and 2015 by the CMS detector at the Large Hadron Collider. The event selection criteria used in these analyses yields 322 and 46 observed events in data in 2012 and 2015, respectively, while the estimated background yield from theoretical predictions is 342.1~$\pm$~22.2 and 54.3~$\pm$~17.7. These observations are consistent with the standard model next-to-leading order QCD predictions. Given the limitation in statistics to measure the cross section for this production process, an upper limit of 3.4 times the standard model predictions is made at a 95\% confidence level for WV$\gamma$ with photon $p_{T}$ greater than 30~GeV and absolute pseudorapidity less than 1.44. Physics beyond the standard model, such as anomalous couplings between the gauge bosons at the quartic vertex, may lead to enhancement in the number of WV$\gamma$ events produced within high energy collisions. Such enhancements can be observed in kinematic distributions, particularly in the higher energy regions. No evidence of anomalous WW$\gamma\gamma$ and WWZ$\gamma$ quartic gauge boson couplings is found, while 95\% confidence level upper limits are obtained for various couplings.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

A Search for New Resonances with the Dijet Angular Ratio Using the Compact Muon Solenoid Experiment

A search for dijet resonances is performed using 2.2 fb$^{-1}$ of proton-proton collision data at $\sqrt{s}$ = 7 TeV recorded by the CMS detector at CERN. The study is based on the dijet angular ratio, the ratio of the number of events with the two leading jets having pseudorapidity difference |delta eta| < 1.3 to the number of events with 1.3 < |delta eta| < 3.0. Models of new resonances which decay into two jets typically predict dijet angular distributions and hence, values of the dijet angular ratio which differ from standard model processes. We thus use the measurement of the angular ratio as a function of mass to set limits on the cross sections of new spin -1/2 quark-gluon resonances. We exclude excited quarks of mass less than 3.2 TeV at 95% confidence level, where a limit of 2.8 TeV is expected.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

The Assessment and Validation of Mini-Compact Tension Test Specimen Geometry and Progress in Establishing Technique for Fracture Toughness Master Curves for Reactor Pressure Vessel Steels

Small specimens are playing the key role in evaluating properties of irradiated materials. The use of small specimens provides several advantages. Typically, only a small volume of material can be irradiated in a reactor at desirable conditions in terms of temperature, neutron flux, and neutron dose. A small volume of irradiated material may also allow for easier handling of specimens. Smaller specimens reduce the amount of radioactive material, minimizing personnel exposures and waste disposal. However, use of small specimens imposes a variety of challenges as well. These challenges are associated with proper accounting for size effects and transferability of small specimen data to the real structures of interest. Any fracture toughness specimen that can be made out of the broken halves of standard Charpy specimens may have exceptional utility for evaluation of reactor pressure vessels (RPVs) since it would allow one to determine and monitor directly actual fracture toughness instead of requiring indirect predictions using correlations established with impact data. The Charpy V-notch specimen is the most commonly used specimen geometry in surveillance programs. Assessment and validation of mini-CT specimen geometry has been performed on previously well characterized HSST Plate 13B, an A533B class 1 steel. It was shown that the fracture toughness transition temperature measured by these Mini-CT specimens is within the range of To values that were derived from various large fracture toughness specimens. Moreover, the scatter of the fracture toughness values measured by Mini-CT specimens perfectly follows the Weibull distribution function providing additional proof for validation of this geometry for the Master Curve evaluation of rector pressure vessel steels. Moreover, the International collaborative program has been developed to extend the assessment and validation efforts to irradiated weld metal. The program is underway and involves ORNL, CRIEPI, and EPRI.

36 MATERIALS SCIENCE↗

AGR-1 Compact 5-3-1 Post-Irradiation Examination Results

The Advanced Gas Reactor (AGR) Fuel Development and Qualification Program was established to perform the requisite research and development on tristructural isotropic (TRISO) coated particle fuel to support deployment of a high-temperature gas-cooled reactor (HTGR). The work continues as part of the Advanced Reactor Technologies (ART) TRISO Fuel program. The overarching program goal is to provide a baseline fuel qualification data set to support licensing and operation of an HTGR. To achieve these goals, the program includes the elements of fuel fabrication, irradiation, post-irradiation examination (PIE) and safety testing, fuel performance, and fission product transport (INL 2015). A series of fuel irradiation experiments is being planned and conducted in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). These experiments will provide data on fuel performance under irradiation, support fuel process development, qualify the fuel for normal operating conditions, provide irradiated fuel for safety testing, and support the development of fuel performance and fission product transport models. The first of these irradiation tests, designated AGR-1, began in the ATR in December 2006 and ended in November 2009. This experiment was conducted primarily to act as a shakedown test of the multicapsule test train design and provide early data on fuel performance for use in fuel fabrication process development. It also provided samples for post-irradiation safety testing, where fission product retention of the fuel at high temperatures will be experimentally measured. The capsule design and details of the AGR-1 experiment have been presented previously.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

AGR-1 Compact 1-3-1 Post-Irradiation Examination Results

The Advanced Gas Reactor (AGR) Fuel Development and Qualification Program was established to perform the requisite research and development on tristructural isotropic (TRISO) coated particle fuel to support deployment of a high-temperature gas-cooled reactor (HTGR). The work continues as part of the Advanced Reactor Technologies (ART) TRISO Fuel program. The overarching program goal is to provide a baseline fuel qualification data set to support licensing and operation of an HTGR. To achieve these goals, the program includes the elements of fuel fabrication, irradiation, post-irradiation examination (PIE) and safety testing, fuel performance modeling, and fission product transport (INL 2015). A series of fuel irradiation experiments is being planned and conducted in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). These experiments will provide data on fuel performance under irradiation, support fuel process development, qualify the fuel for normal operating conditions, provide irradiated fuel for safety testing, and support the development of fuel performance and fission product transport models. The first of these irradiation tests, designated AGR-1, began in the ATR in December 2006 and ended in November 2009. This experiment was conducted primarily to act as a shakedown test of the multicapsule test train design and provide early data on fuel performance for use in fuel fabrication process development. It also provided samples for post-irradiation safety testing, where fission product retention of the fuel at high temperatures will be experimentally measured. The capsule design and details of the AGR-1 experiment have been presented previously (Grover, Petti, and Maki 2010, Maki 2009).

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

Radial Deconsolidation of Leach-Burn-Leach of AGR-3/4 Compacts 3-3, 12-1, and 12-3

The Advanced Gas Reactor (AGR) Fuel Development and Qualification Program was established to perform the requisite research and development on tristructural isotropic (TRISO)-coated particle fuel to support deployment of a high-temperature gas-cooled reactor (HTGR). The work continues as part of the Advanced Reactor Technologies (ART) TRISO Fuel Program. The overarching goal of the program is to provide a baseline fuel qualification data set to support licensing and operation of an HTGR. To achieve these goals, the program includes the elements of fuel fabrication, irradiation, post-irradiation examination (PIE) and safety testing, fuel performance modeling, and fission product transport (INL 2016). A series of fuel irradiation experiments is being performed at the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). These experiments are intended to provide data on fuel performance under irradiation, support fuel fabrication process development, qualify fuel for operating and accident conditions, provide irradiated fuel for accident testing, and support development of fuel performance and fission product transport models.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Compact, single mode, frequency stabilized laser spectroscopy sources for isotope analysis

We will discuss here ultra-stable narrow line-width Hybrid External Cavity Lasers (HECL) of visible spectrum. The customer requires ~ 2 MHz linewidth / stability (2.7 fm). It is our goal to design the most stable possible ECL, and then enhance its long-term stability by disciplining it to an atomic wavelength reference. Protection against long-term drift can be provided by calibrating HECL wavelength to a hollow-cathode lamp (HCL) standard using the optogalvanic effect to adjust the HECL set-point. Here we report the short-term stability of the HECL alone, i.e., without the discipline of an atomic wavelength reference. For this purpose, we have studied HECLs operating at 405 nm and at 638 nm. We will interpret their performance in terms of the customer’s need for 600 – 700 nm narrow-linewidth spectroscopy. We selected to perform the portion of the work at 405 nm since the sensitivity to cavity stability is ~2x compared with operating in the 600 – 700 nm wavelength range. Further, we will show excellent wavelength stability over time at 638 nm. The two main ECL components are the semiconductor laser chip, including a high reflectivity (HR) mirror, and a volume Bragg grating (VBG) that provides output coupling. Between them is collimating optics. The theoretical analysis and experimental data suggest that control of ECL wavelength in the femtometer wavelength range can be achieved over short-term time scales by carefully controlling both the temperature and very high current stability. From the results presented here temperature control of the laser to 0.001° C along with current stability of 0.001 mA will be needed in a sensor instrument. Finally, we show a path to achieve 2 MHz short-term stability at 600 to 700 nm.

07 ISOTOPE AND RADIATION SOURCES↗