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At least 1,351 records · Page 75

Bounding the Higgs Width at the LHC

We present results for the Standard model description of the four-lepton production, mediated both by Higgs boson production and by other one-loop standard model processes. The description of four-lepton final states in MCFM v6.8 is reviewed, with special reference to the interference effects that can occur for identical species of leptons. We present results both for interference in the $l^+l^- l^- l^+$ and in the $l^-l^+ \nu_l \bar{\nu}_l$ final state. Prospects for further improvement in the theoretical description of four lepton production are also reviewed.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Impingement cooling arrangement having a snap-in plate

A cooling arrangement (100), including: a substrate having a pocket (24) defined by a rib side surface (28) and a bottom surface (26); a feature (112) formed in the rib side surface; and an impingement plate (102). In an installed configuration (116) a resilience of the impingement plate enables an interference between the impingement plate and the feature that locks the impingement plate in an installed position (118). An elastic compression of the impingement plate from the installed configuration eliminates the interference.

42 ENGINEERING↗

Technical Requirements for Geothermal Resource Confirmation

In 2017-2018, the Bureau of Land Management's Renewable Energy Coordination Office, through its Geothermal Program, funded the National Renewable Energy Laboratory (NREL) to analyze technical and environmental considerations related to geothermal resource confirmation drilling. NREL solicited input from a group of technical and environmental experts in the geothermal industry, along with analyzing National Environmental Policy Act of 1969 (NEPA) documentation for previously approved projects. The collected data and analysis will be used by the Bureau of Land Management to examine the possibility of developing a new classification of wells and/or expediting the NEPA compliance process, which could potentially reduce permitting and regulatory compliance timelines when compared to the current process for obtaining a geothermal drilling permit for resource confirmation drilling activities. This paper provides a summary of the technical requirements for confirming a geothermal resource. The analysis showed that confirming a geothermal resource requires confirming reservoir temperature, chemistry, permeability, and flow rate. Obtaining these data requires drilling at least two-preferably three-successful wells into the resource to conduct the necessary tests, including an interference test. Bottom-hole well diameters of at least 6'' to 8'' (0.15 to 0.2 m) are needed to limit the wellbore frictional pressure drop to effectively perform well flow and interference tests. Drilling these wells requires a drill rig with a mud pump and derrick capable of holding three drill pipes. This type of rig requires a minimum well-pad size of 2.5 acres (104 m2) including surface area for a 1 million-gallon (3.8 million-liter) pit. Up to 15 acres (5x104 m2) of total surface disturbance are needed for developing access roads and well pads to drill a total of three to five wells.

15 GEOTHERMAL ENERGY↗

Pulse Shaping and Matched Filters for EMAT Communication System

Electromagnetic acoustic transducer (EMAT) is used as a noncontact sensor for acoustic communication in a stainless-steel plate channel. The acoustic wave multipath propagations within the channel cause intersymbol interference (ISI). ISI highly degrades the signal-to-noise ratio (SNR). The poor SNR will result in a low bitrate and a high bit error rate (BER). In this study, a test platform is designed to estimate the performance of the EMAT communication system. Two periodic-permanent-magnet (PPM) EMATs are designed to be used as a transmitter and a receiver. EMAT generates shear-horizontal (SH) wave propagating through the stainless-steel plate channel. We present methods to minimize the ISI effect and recover the message embedded in the received signals hampered by interference, reverberation and multipath effects. The root raised cosine (RRC) filters are introduced as a pulse-shaping filter for transmission and a matched filter for receiving messages. Amplitude Shift Keying (ASK) method is used for modulating the transmitted binary message. The pulse shaping and matched filters reduced the ISI caused by the undesirable multipath effect significantly to the extent that a 5-kbps bitrate can be achieved without any error (zero BER).

Huang, Xin↗

Highly Selective and Stable Multivariable Gas Sensors for Enhanced Robustness and Reliability of SOFC Operation

GE Global Research, in partnership with SUNY Polytechnic Institute (SUNY Poly) and GE–Fuel Cells LLC, designed, built, and tested multi-gas sensor prototypes for in situ monitoring of gases produced during steam reforming in solid oxide fuel cell (SOFC) systems. To be widely adopted and to deliver a lower operating cost for customers, SOFC systems should enhance their operation reliability and improve stack robustness. These needs can be achieved by early diagnostics of potential upsets by using in-situ gas sensors for the real-time monitoring of gas mixture compositions. Thus, this project objective was to achieve selectivity and stability of sensing of gases for SOFC applications by implementing a new generation of gas sensors, known as multivariable sensors. Such sensors are intended to complement the mature traditional analytical instruments based on sensor performance and design characteristics. The key sensor-performance characteristics include accurate detection and quantitation of several gases in their mixtures and stability of operation in unattended applications. The key design characteristics of sensors include their unobtrusive form factor and cost-effectiveness. The duration of the project was 18 months with the project structure that included three technical tasks such as (1) design and laboratory validation of multivariable sensors for selective detection of H 2 and CO gases, (2) laboratory validation of sensor stability over a two-week testing, and (3) field-validation of the developed multivariable sensor system prototype at GE–Fuel Cells factory. Multi-gas detection was achieved with multivariable photonic sensors designed to operate at elevated temperature. The sensor design was based on three-dimensional (3D) bio-inspired photonic nanostructure that was fabricated using materials responsive to gases of interest such as H 2 and CO. The gas discrimination and the rejection of interferences such as CH 4 , H 2 O, and others was performed by optimizing the design parameters of the 3D photonic nanostructures such as their composition and morphology. Planar sol-gel and sputtered sensing films were fabricated as controls. As a result of the fabrication, functionalization, excitation, and performance testing of 3D photonic sensors, we developed initial design rules for high temperature multivariable sensors. These design rules pave the way for the new generation of cost-effective industrial sensors. Stability of sensor operation was tested in the laboratory conditions under variations of the ambient environments. Stability tests were designed in the order of enhanced complexity and realism of sensor operation and included quantitation of a single gas, quantitation of a single gas in the presence of interferences, and quantitation of two and three gases. We have found that conventional machine learning data analysis stools were unable to correct for the sensor drift. Thus, we have developed new methods of machine learning data analysis that provided us with needed performance stability. Such performance improvement in gas sensing was a significant milestone in bringing our multivariable sensors to practical applications. The project culminated with initial field validation of developed multivariable sensor prototypes at GE–Fuel Cells LLC. The in situ data generated by the sensor system in the lab and field conditions provided inputs that advanced our fundamental understanding of gas sensing at high temperatures to enable sensors for SOFC applications and allowed development of the recommendations for further deliverables.

47 OTHER INSTRUMENTATION↗

INL WTB Overview Capabilities Future v14_040419

INL Wireless Test Bed Mission Provide highly-regarded cellular, wireless and communications technical expertise, systems and environment to enable: Test & Demonstrate full scale wireless systems and equipment With and without controlled interference Terrestrial, Subterranean and Airborne Demonstrate new & emerging wireless technologies Develop and Train to Tactics, Techniques and Procedures (TTPs) for wireless systems In a real world environment and configurations at real frequencies and real power levels to make informed decision State-of-the-Art INL WTB Assets and Capabilities Instrumentation: RF waveform analyzers, generators Protocol analyzers Noise generators for controlled interference Established Services & Processes: Spectrum approval & monitoring Safety, Medical, Fire, Security (physical) Resource management - personnel, networks, configuration control Secure, IP protected multi-user facility Broadband data access – entire INL Range Hardware prototyping, scientific labs Visitor – US citizen & foreign national

2G↗

Systems and methods for interferometric end point detection for a focused ion beam fabrication tool

Various technologies for providing an operator of a focused ion beam (FIB) system with navigational and processing data are described herein. An exemplary system includes a broadband light source and a narrowband light source that emit light to a target of the FIB. An optical detector receives reflections of the broadband light from the target and outputs data that is used to generate two-dimensional images of the target in a region near a location of incidence of the FIB at the target. An interferometer receives reflections of the narrowband light from the target and outputs data indicative of an interference pattern of the narrowband reflections. A computing device computes a thickness of one or more material layers that make up the target based upon the interference pattern. A two-dimensional image of the target and an indication of the computed thickness are then displayed to the operator of the FIB.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Research plan for the development of optical fiber pressure sensors for nuclear applications

Fiber optic pressure sensors are desirable for nuclear applications because they are low mass/small size, immune to electromagnetic interference, high sensitivity, and have multiplexing and multimodal measurement capabilities. Much research and development has been conducted on developing fiber optic based sensors and they are now considered a class of standard instrumentation in many industries. Specifically, for pressure sensing, a wide range of fiber based sensors have been developed for various pressure ranges and environments. This vast body of research will be leveraged for the development of pressure sensors for nuclear applications. Four pressure measurement scenarios were considered which would benefit from a fiber optic based pressure sensor. These scenarios include pressure measurement in the fuel rod plenum, coolant pressure during LOCA testing, advanced coolant (helium, sodium, molten salt) pressure for flow loop operation, and high pressures resulting for direct fuel-coolant interaction. Each scenario has unique pressure, temperature, and material requirements for the sensor. From a survey of commercially available sensors and a literature review; it has been determined that an extrinsic Fabry-Perot interferometer approach is the most appropriate for the various measurement requirements. The experience and knowledge base for Fabry-Perot interferometers can be leveraged since they are the most common fiber optic based pressure sensors available commercially and found in literature. These pressure sensors rely on the interference of light in a gas filled cavity, which minimizes the impact of radiation induced attenuation and compaction on the measurement, compared to intrinsic sensing techniques. The measurement range of these sensors is based on the stiffness of the diaphragm that deflects under pressure. This allows for a suite of fiber based sensors to be developed by interchanging this diaphragm for the requirements of each application. Key material and design considerations have been identified for the development of a Fabry-Perot interferometry pressure measurement for nuclear applications. These include high temperature bonding between the glass fiber optic and metal housing, identifying diaphragm materials & geometry, and minimizing cross sensitivity to temperature or implementing compensation techniques found in literature. Overcoming these challenges will develop a pathway for a fiber optic based pressure sensor for nuclear applications, and additionally can be leveraged for other sensing application based on Fabry-Perot interferometers, such as temperature, strain (creep & deformation), vibration, and index of refraction.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

User defined intensity profile laser beam

A high-power laser beam with an arbitrary intensity profile is produced. Such beam has a variety of uses including for laser materials processing such as powder bed fusion additive manufacturing. Several challenges in additive manufacturing are mitigated with the present non-uniform intensity laser profiles. Nonuniform shapes include a set of intensity pixels in a line that could print a wide stripe area instead of just a single line. One example uses the multimode interference pattern from the output of a ribbon fiber which is imaged onto a work piece. The interference pattern is controlled to allow turning on or off of ‘pixels’ along a line which can be used to shape the beam and form the additively manufactured part.

Drachenberg, Derrek R.↗

Blade and airfoil damping configurations

The present embodiments set forth a blade including an airfoil, the airfoil including a tip cap, a pressure sidewall and a suction sidewall extending axially between corresponding leading and trailing edges and radially between the base and the tip cap. The blade, including the airfoil and base, being formed in at least two airfoil parts, each of the two airfoil parts including contacting edges engaging each other respective contacting edges, the contacting edges defining a joint for preloading each of the at least two parts with each other and with the base. The at least two airfoil parts forming the airfoil being retained to each other by an interference fit at the joint. The interference fit providing frictional damping of vibrations in the blade during blade operation.

Hart, Andrew Clifford↗

Application of wavelet scaling function expansion continuous-energy resonance calculation method to MOX fuel problem

More and more MOX fuels are used in all over the world in the past several decades. Compared with UO{sub 2} fuel, it contains some new features. For example, the neutron spectrum is harder and more resonance interference effects within the resonance energy range are introduced because of more resonant nuclides contained in the MOX fuel. In this paper, the wavelets scaling function expansion method is applied to study the resonance behavior of plutonium isotopes within MOX fuel. Wavelets scaling function expansion continuous-energy self-shielding method is developed recently. It has been validated and verified by comparison to Monte Carlo calculations. In this method, the continuous-energy cross-sections are utilized within resonance energy, which means that it's capable to solve problems with serious resonance interference effects without iteration calculations. Therefore, this method adapts to treat the MOX fuel resonance calculation problem natively. Furthermore, plutonium isotopes have fierce oscillations of total cross-section within thermal energy range, especially for {sup 240}Pu and {sup 242}Pu. To take thermal resonance effect of plutonium isotopes into consideration the wavelet scaling function expansion continuous-energy resonance calculation code WAVERESON is enhanced by applying the free gas scattering kernel to obtain the continuous-energy scattering source within thermal energy range (2.1 eV to 4.0 eV) contrasting against the resonance energy range in which the elastic scattering kernel is utilized. Finally, all of the calculation results of WAVERESON are compared with MCNP calculation. (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Pyroprocessing of oxidized sodium-bonded fast reactor fuel - An experimental study of treatment options for degraded EBR-II fuel

An experimental study was conducted to assess pyrochemical treatment options for degraded EBR-II fuel. As oxidized material, the degraded fuel would need to be converted back to metal to enable electrorefining within an existing electro-metallurgical treatment process. A lithium-based electrolytic reduction process was studied to assess the efficacy of converting oxide materials to metal with a particular focus on the impact of zirconium oxide and sodium oxide on this process. Bench-scale electrolytic reduction experiments were performed in LiCl-Li{sub 2}O at 650 C. degrees with combinations of manganese oxide (used as a surrogate for uranium oxide), zirconium oxide, and sodium oxide. In the absence of zirconium or sodium oxide, the electrolytic reduction of MnO showed nearly complete conversion to metal. The electrolytic reduction of a blend of MnO-ZrO{sub 2} in LiCl - 1 wt% Li{sub 2}O showed substantial reduction of manganese, but only 8.5% of the zirconium was found in the metal phase. The electrolytic reduction of the same blend of MnO-ZrO{sub 2} in LiCl - 1 wt% Li{sub 2}O - 6.2 wt% Na{sub 2}O showed substantial reduction of manganese, but zirconium reduction was even less at 2.4%. This study concluded that ZrO{sub 2} cannot be substantially reduced to metal in an electrolytic reduction system with LiCl - 1 wt% Li{sub 2}O at 650 C. degrees due to the perceived preferential formation of lithium zirconate. This study also identified a possible interference that sodium oxide may have on the same system by introducing a parasitic and cyclic reaction of dissolved sodium metal between oxidation at the anode and reduction at the cathode. When applied to oxidized sodium-bonded EBR-II fuel (e.g., U-10Zr), the prescribed electrolytic reduction system would not be expected to substantially reduce zirconium oxide, and the accumulation of sodium in the electrolyte could interfere with the reduction of uranium oxide, or at least render it less efficient.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

A Rapid Sequential Separation Method for Determination of Actinides and TENORM in Fracking Wastes - 20223

With recent advances in unconventional drilling technology in the US and around the world, the risks of environmental contamination and exposure due to technologically enhanced naturally occurring radioactive materials (TENORM) from fracking wastes have also surfaced. Although the Permian Basin (southeastern New Mexico, western Texas) has long been a modest producer of oil, the advent of fracking technology a decade ago turned it into hot property for producers. A 2018 assessment of undiscovered, technically recoverable continuous oil and gas resources by the U.S. Geological Survey estimates an average 46.3 billion barrels of oil and 281 trillion cubic feet of gas. This is likely to increase the use of unconventional drilling and TENORM generation. TENORM concentrations in oil and gas exploration and production waste can be several hundred to several thousand times higher than background TENORM concentrations. Both the thorium and uranium decay chains contribute to airborne radionuclides arising from the radon gas escaping the ground and subsequently decaying as airborne particulates. Additionally, radon decay products {sup 210}Pb and {sup 210}Po can build up in scale on the internal surfaces of oil and gas handling pipes and in sludge in refineries, becoming potential inhalation and ingestion hazards for workers. Furthermore, southeastern NM is also home to world's only licensed and operating transuranic nuclear waste repository, the DoE's Waste Isolation Pilot Plant (WIPP). Plutonium isotopes ({sup 239+240}Pu) and {sup 241}Am, are expected to account for more than 99% of the total radioactivity scheduled for disposal in the WIPP repository. Thus, an improved understanding of the environmental fate and transport of TENORM, liberated by unconventional drilling, is essential to assess how best to protect individuals and the environment. In this context, accurate measurement of TENORM and actinides in environmental and biological samples is essential. In this presentation, a new sequential method for the separation and pre-concentration of actinides (Pu, Am, Np) and TENORM (Po, U and Th) derived from oil and gas exploration is proposed. The TEVA method involves a rapid co-precipitation step to remove matrix interferences from the samples, followed by plutonium oxidation state adjustment to Pu (IV) and an incubation period of ∼ 1 hour at 50-60 deg. C to allow the resultant Po (II) to oxidize into Po(IV). The polonium, neptunium, thorium and plutonium are then separated on a TEVA column, while americium and uranium are separated on a TRU column. After separation, the alpha counting source was prepared by micro-precipitation with copper sulfide (CuS) for polonium and neodymium fluoride (NdF{sub 3}) for actinides. The efficiency and reliability of the procedures were tested by analyzing filter, drinking water and frack sand samples. The method is simple, robust and can be performed quickly with excellent removal of interferences, high chemical recovery and very good alpha peak resolution. (authors)

07 ISOTOPE AND RADIATION SOURCES↗

Co-existence of Heterogeneous Wireless Networks in 2.4 GHz and 5 GHz Spectrum

To achieve automation across different applications, next-generation nuclear power plants are beginning to leverage advanced wireless technologies. The deployment of these wireless technologies is a salient need for modernizing the existing nuclear plants. A “one-size-fits-all” solution cannot be adopted since wireless technologies are selected according to specific application needs, quality of service, and economic restrictions. To balance the trade-off between technical and economic requirements, a multi-band heterogeneous wireless network architecture is needed. However, the co-existence of these multi-band wireless technologies poses numerous challenges. Due to factors including dissimilarity in channel access mechanisms, transmit power levels, distance between nodes, and interference among co-existing solutions, performance can be seriously degraded, leading to very low signal-to-noise ratio. This report builds on our previous study, "Experimental Evaluation of Interference in 2.4 GHz Wireless Network," which analyzed the performance of wireless communication technologies such as Wi-Fi, Zigbee, and Bluetooth co-existing within the 2.4 GHz band. We now extend this study by developing a new upper-layer approach that uses rate control to create temporary opportunities for signal transmission while using the shared band. Unlike existing work in the literature, our approach does not require modifications at the link or physical layers of the network. Further, we extend our work to explore the co-existence of Wi-Fi and fifth-generation (5G) in the 5 GHz unlicensed spectrum, using both experiments and simulations. This report provides a technical foundation for understanding the operational designs of Wi-Fi and 5G in the unlicensed band and evaluates their performance when these networks co-exist. Our findings show that the performance of 5G can be improved by controlling the Wi-Fi’s packet rate at the upper layer.

42 ENGINEERING↗

Mechanical Actuation Mechanism Design for Cryogenic Microwave Cavities in Axion Dark Matter Searches

Resonant Microwave Cavities are placed in a strong magnetic field at cryogenic temperatures (~.1K) in order to try to convert axions into detectable photons. A major challenge is to tune the cavity to allow no interference with the desired environment used for the experiment, which enables the system to operate near absolute zero and maintain superconductivity, thereby reducing noise as much as possible. My project focuses on developing and testing a low-thermal-conductivity gear reduction system with a 1000:1 ratio for cavity tuning. This gear system could significantly improve the thermal and electromagnetic interference of the tuning mechanism, helping ADMX scan for axions more accurately.

Ortega, Giancarlo [Marquette U.; Fermilab]↗

Exploring Resonance Structures in the Partial-Wave Analysis of ¿p0 Photoproduction at GlueX

This thesis studies what happens when a photon (¿) collides with a proton (p) and produces a neutral omega (¿) and pion (p0) pair, with a recoiling proton (p'), expressed as ¿p ¿ ¿p0p'. We study this and other reactions to better understand the strong nuclear force; one of the four fundamental forces that govern all the physics of the universe. This force is specifically responsible for the binding and decay of subatomic particles, such as the ones here. While we understand the ¿ and p0, what we are actually interested in is a short-lived unknown particle X that decays via X ¿ ¿p0. There are a multitude of possible particles X can be, and so our focus in this work is to find out what X is by determining its properties from the particles we measure. We do this via an intricate analysis procedure known as “partial-wave analysis”. By analogy, one can think of our particle detector as a buoy, and the particles we want to analyze (X) as pebbles hitting a pond. The waves created by the pebble will move our buoy, giving us information about the pebble that produced the wave. However, when multiple pebbles hit our pond, the waves overlap and interfere with each other. Our buoy only can measure the complicated interfering result of all the waves. To disentangle this, our partial-wave analysis works by modeling this interference pattern so that we may infer the properties of the pebbles (particles) we produced. In this thesis, we review the relevant experimental history in photoproduction and related production mechanisms, as well as the theoretical foundations that motivate our measurement. We describe the methods used to collect our data at the GlueX experiment stationed at the Jefferson Lab accelerator facility in Newport News, Virginia. We then detail the selections we apply to ensure our events are almost exclusively ¿p ¿ ¿p0p'. We cover the intensity model, how we verify its capabilities, and finally present our results together with systematic studies. Our primary result is the detection of a b1(1235) meson interfering with a wide JPC = 1-- vector state, measured via a mass-independent partial-wave analysis. It provides precise experimental results that can be used as input for theoretical models of the reaction, yielding conclusions about the procedures responsible for how our universe behaves at its most basic level.

Scheuer, Kevin [College of William and Mary, Willi↗

Measurement and feedback-driven adaptive dynamics in the classical and quantum kicked top

In classical dynamical systems, stochastic feedback can stabilize otherwise unstable periodic orbits, giving rise to distinct controlled and uncontrolled phases as the rate of control application is varied. In this work, we apply these control protocols in classical, semiclassical, and quantum regimes to the kicked top, a paradigmatic model of quantum chaos. The quantum kicked top, modeled as the dynamics of a spin-S object, naturally interpolates between these regimes with the spin size S acting as an effective Planck constant. We show that the dynamics of the kicked top in classical, semiclassical, and fully quantum limits can all be controlled using stochastic feedback protocols. Comparing the full quantum dynamics to a truncated Wigner approximation that captures quantum noise but neglects interference beyond the Ehrenfest time, we find that low-moment observables are largely accounted for semiclassically, while the remaining discrepancy in higher moments is consistent with contributions from interference and possibly nonlinearities in rare trajectories that explore the compact phase space. We also find rapid purification in the numerics studied for all rates of control considered, suggesting that control quenches the top's ability to encode a qubit of quantum information even in the uncontrolled phase.

Prasad, Mahaveer [Tata Inst.; Singapore U. Tech. D↗

Lightweight, Flexible Electromagnetic Shielding Composite Films Reinforced with Recycled Carbon Fibers and Carbon Nanofillers

Lightweight, flexible polymer composites are widely adopted in modern electronic devices and systems for high-efficiency electromagnetic interference (EMI) shielding. Reinforcing polymer composites with conductive fillers offers a promising alternative to conventional metal-based shielding material thanks to their low density, tunable properties, and flexibility. Herein, lightweight, flexible ultra-high molecular weight polyethylene composite films reinforced with recycled carbon fibers (rCFs) and carbon-based nanofillers, including graphene nanoplatelets (GNPs) and carbon nanotubes, are reported for EMI shielding applications. The incorporation of these nanofillers significantly reduces the required content of rCFs and improves processability while maintaining comparable shielding effectiveness. The addition of these nanofillers with rCFs enhances the EMI shielding effectiveness by up to 15 dB. Incorporating 1 wt% GNPs can replace 5 wt% rCFs and achieve comparable EMI shielding performance, while 5 wt% of either nanofillers can substitute for 10 wt% rCFs. Numerical modeling of electromagnetic wave transmission reveals that increasing nanofiller concentrations enhances both reflection and absorption losses, with absorption consistently dominating across all levels. Furthermore, this study not only provides insight into the synergistic contributions of rCFs and carbon nanofillers to shielding effectiveness but also paves the way for the design of sustainable, lightweight EMI shielding composite films for applications in electric vehicles, medical equipment, and portable electronics.

carbon nanofiller↗