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DOE OSTI2015

Trustworthy Cyber Infrastructure for the Power Grid (TCIPG) Final Technical Report - November 20, 2015

The Trustworthy Cyber Infrastructure for the Power Grid project (TCIPG) was funded by DOE and DHS for a period of performance that ran from October 1, 2009 to August 31 2015. The partnership included the University of Illinois at Urbana-Champaign (lead institution) and partner institutions Arizona State University (replacing original partner UC Davis when faculty moved), Dartmouth College, and Washington State University. TCIPG was a unique public-private partnership of government, academia, and industry that was formed to meet the challenge of keeping our power grid secure. TCIPG followed from the earlier NSF-funded TCIP project, which kicked off in 2005. At that time, awareness of cyber security and resiliency in grid systems (and in control systems in general) was low, and the term “smart grid” was not in wide use. The original partnership was formed from a team of academic researchers with a shared vision for the importance of research in this area, and a commitment to producing more impactful results through early involvement of industry. From the TCIPG standpoint, “industry” meant both utilities (investor-owned as well as cooperatives and municipals) and system vendors (who sell technology to the utility sector). Although TCIPG was a university-led initiative, we have from the start stressed real-world impact and partnership with industry. That has led to real-world adoption of TCIPG technologies within the industry, achieving practical benefits. This report summarizes the achievements of TCIPG over its period of performance.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2016

Proposed Activities to Address Regulatory Gaps and Challenges for Licensing Advanced Reactors Using Seismic Isolation

Over the last decade, particularly since implementation of the certified design regulatory approaches outlined in 10 CFR 52, “Licenses, Certifications, and Approvals for Nuclear Power Plants,” interest has been increasing in the use of seismic isolation (SI) technology to support seismic safety in nuclear facilities. In 2009, the United States (U.S.) Nuclear Regulatory Commission (NRC) initiated research activities to develop new guidance targeted at isolated facilities because SI is being considered for nuclear power plants in the U.S. One product of that research, which was developed around a risk-informed regulatory approach, is a draft NRC NUREG series (NUREG/CR) report that investigates and discusses considerations for use of SI in otherwise traditionally founded large light water reactors (LWRs). A coordinated effort led to new provisions for SI of LWRs in the American Society of Civil Engineers standard ASCE/SEI 4-16, “Seismic Analysis of Safety Related Nuclear Structures.” The risk-informed design philosophy that underpinned development of the technical basis for these documents led to a set of proposed performance objectives and acceptance criteria intended to serve as the foundation for future NRC guidance on the use of SI and related technology. Although the guidance provided in the draft SI NUREG/CR report and ASCE/SEI 4 16 provides a sound basis for further development of nuclear power plant designs incorporating SI, these initial documents were focused on surface-founded or near-surface-founded LWRs and were, necessarily, limited in scope. For example, there is limited information in both the draft NUREG/CR report and ASCE/SEI 4-16 related to nonlinear analysis of soil-structure systems for deeply-embedded reactors, the isolation of components, and the use of vertical isolation systems. Also not included in the draft SI NUREG/CR report are special considerations for licensing of isolated facilities using the certified design approach in 10 CFR 52 and a detailed discussion of seismic probabilistic risk assessments for isolated facilities.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2017

Research Library Year in Review 2016

2016 was a year of strategy, analysis and moving forward. We launched January with a strategic planning process. Building on the Lab’s Strategic Plan and Purpose Statement, we created a process that reached out to Lab leadership, scientists & engineers, and Research Library (RL) staff. An external consultant was engaged to help drive the process and to lead a fullday staff retreat. A survey was created and administered to staff, seeking feedback on priorities and direction. A parallel survey was created for stakeholders. Stakeholder questions began with the macro – from the external climate to Lab and division priorities – to the micro concerning priorities and directions for the RL. Stakeholders were personally interviewed by teams of two that included an interviewer and a scribe. These thirty-plus interviews were collated into a spreadsheet. A sociologist provided semantic analysis for the feedback, creating an impact document of the interviews. The full day retreat provided an opportunity for staff to build on their feedback as well as stakeholder feedback. A great deal of brainstorming led to categorized priorities and scenarios. The RL Compass Team, encompassing library leadership, moved the next stage of the process forward by taking retreat feedback and creating a first draft of a plan. Two more rounds of feedback with smaller staff groups as well as the Library Advisory Board led to the final plan. The core plan is included in this report.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗
DOE OSTI2017

The Effect of Airborne Contaminants on Fuel Cell Performance and Durability

The impact of contaminants on fuel cell performance was examined to document air filter specifications (prevention) and devise recovery procedures (maintenance) that are effective at the system level. Eight previously undocumented airborne contaminants were selected for detailed studies and characterization data was used to identify operating conditions that intensifying contamination effects. The use of many and complementary electrochemical, chemical and physical characterization methods and the derivation of several mathematical models supported the formulation of contamination mechanisms and the development of recovery procedures. The complexity of these contamination mechanisms suggests a shift to prevention and generic maintenance measures. Only two of the selected contaminants led to cell voltage losses after injection was interrupted. Proposed recovery procedures for calcium ions, a component of road de-icers, dessicants, fertilizers and soil conditioners, were either ineffective or partly effective, whereas for bromomethane, a fumigant, the cell voltage was recovered to its initial value before contamination by manipulating and sequencing operating conditions. However, implementation for a fuel cell stack and system remains to be demonstrated. Contamination mechanisms also led to the identification of membrane durability stressors. All 8 selected contaminants promote the formation of hydrogen peroxide, a known agent that can produce radicals that attack the ionomer and membrane molecular structure whereas the dehydrating effect of calcium ions on the ionomer and membrane increases their brittleness and favors the creation of pinholes under mechanical stresses. Data related to acetylene, acetonitrile and calcium ions are emphasized in the report.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2017

Final Report for DE-SC0008059

Graphene, a one-atom thick material comprising hexagonally bonded carbon atoms, is one of the strongest materials known and is impermeable to even helium gas. The potential for creation of tunable nanometer-scale pores in graphene, combined with mechanical strength, chemical resistance, and atomic thickness, make it a promising material for improving selectivity, permeability, and energy efficiency in a diverse range of membrane separations. However, fundamental understanding of creation of porous graphene, its mass transport properties, and the relationship between porosity and membrane performance is lacking. This project studied methods to create pores in graphene by ion irradiation and etching, and investigated the effect of the porosity of graphene on mass transport properties at the membrane level as well as across individual pores. Detailed characterization of pore size distributions in graphene using high-resolution scanning transmission electron microscopy was performed to elucidate the relationship between different pore creation processes and the resulting porosity. New methods to create tunable nanometer-scale pores in graphene at high density over large areas were developed. Graphene membranes were fabricated comprising single-layer porous graphene on appropriate support membranes. Mass transport of ions, molecules, water, and gases across the membranes was investigated, and predictive models were developed to relate the graphene porosity and support membrane structure to the mass transport properties of the membranes. The effect of graphene porosity on permeance of the membranes to water, salts, and small molecules was experimentally quantified. Single-pore measurements were performed and a model was developed to understand ion transport across graphene pores, which led to the experimental observation of heterogeneity in transport behaviors and spontaneous fluctuations of ion transport. Functional single-layer nanoporous graphene membranes comprising a high density of pores over macro-scale areas with molecular selectivity were demonstrated for the first time. This project led to three patent applications and 9 journal articles. The fundamental developments in understanding nanoporous graphene membranes have laid the foundations to develop energy-efficient nanoporous graphene membranes for various applications in water desalination, oil and natural gas separations, biotechnology, and chemical processing.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Advanced Fuels Campaign 2016 Accomplishments

AFC management and integration activities in FY-16 included continued support for international collaborations, primarily with France, Japan, the European Union, Republic of Korea, and China, as well as various working group and expert group activities in the Organization for Economic Cooperation and Development Nuclear Energy Agency (OECD-NEA) and the International Atomic Energy Agency (IAEA). Three industry-led Funding Opportunity Announcements (FOAs) and two university-led Integrated Research Projects (IRPs) funded in 2013, made significant progress in fuels and materials development. All are closely integrated with AFC and accident-tolerant fuels (ATF) research. Accomplishments made during FY-16 are highlighted in this report, which focuses on completed work and results.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2017

Coupled Thermo-Mechanical and Photo-Chemical Degradation Mechanisms that determine the Reliability and Operational Lifetimes for CPV Technologies

This project sought to identify and characterize the coupled intrinsic photo-chemo-mechanical degradation mechanisms that determine the reliability and operational lifetimes for CPV technologies. Over a three year period, we have completed a highly successful program which has developed quantitative metrologies and detailed physics-based degradation models, providing new insight into the fundamental reliability physics necessary for improving materials, creating accelerated testing protocols, and producing more accurate lifetime predictions. The tasks for the program were separated into two focus areas shown in the figure below. Focus Area 1, led by Reinhold Dauskardt and Warren Cai with a primary collaboration with David Miller of NREL, studied the degradation mechanisms present in encapsulant materials. Focus Area 2, led by Reinhold Dauskardt and Ryan Brock with a primary collaboration with James Ermer and Peter Hebert of Spectrolab, studied stress development and degradation within internal CPV device interfaces. Each focus area was productive, leading to several publications, including findings on the degradation of silicone encapsulant under terrestrial UV, a model for photodegradation of silicone encapsulant adhesion, quantification and process tuning of antireflective layers on CPV, and discovery of a thermal cycling degradation mechanism present in metal gridline structures.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Systems Level Regulation of Rhythmic Growth Rate and Biomass Accumulation in Grasses

Objectives: Several breakthroughs have been recently made in our understanding of plant growth and biomass accumulation. It was found that plant growth is rhythmically controlled throughout the day by the circadian clock through a complex interplay of light and phytohormone signaling pathways. While plants such as the C4 energy crop sorghum (Sorghum bicolor (L.) Moench) and possibly the C3 grass Brachypodium distachyon also exhibit daily rhythms in growth rate, the molecular details of its regulation remain to be explored. A better understanding of diurnally regulated growth behavior in grasses may lead to species-specific mechanisms highly relevant to future strategies to optimize energy crop biomass yield. Here we propose to devise a systems approach to identify, in parallel, regulatory hubs associated with rhythmic growth in C3 and C4 plants. We propose to use rhythmicity in daily growth patterns to drive the discovery of regulatory network modules controlling biomass accumulation. Description: The project is divided in three main parts: 1) Performing time-lapse imaging and growth measurement in B. distachyon and S. bicolor to determine growth rate dynamic during the day/night cycle. Identifying growth-associated genes whose expression patterns follow the observed growth dynamics using deep sequencing technology, 2) identifying regulators of these genes by screening for DNA-binding proteins interacting with the growth-associated gene promoters identified in Aim 1. Screens will be performed using a validated yeast-one hybrid strategy paired with a specifically designed B. distachyon and S. bicolor transcription factor libraries (1000 clones each), and 3) Selecting 50 potential growth regulators from the screen for downstream characterization. The selection will be made by using a sytems biology approach by calculating the connectivity between growth rate, rhythmic gene expression profiles and TF expression profile and determine which TF is likely part of a hub and a potential regulator of plant growth. We will confirme the 50 DNA-protein interactions using transient transcriptional assays in B. distachyon and S. bicolor, and perform further testing in vivo by measuring growth parameters in transgenic loss- or gain-of-function lines for the selected transcription factors (25 B. distachyon and 3 S. bicolor lines). In 2016 the Principal Investigator relocated the laboratory to The Scripps Research Institute (TSRI) where the project has continued with an end date of 08/31/17. Accomplishments: We successfully collected large datasets of gene expression form the model grass Brachypodium. We used and developed bioinformatics analysis tools to investigate the structure, dynamics and robustness of circadian regulated gene expression in Brachypodium. Relevant Discoveries: We were able to determine that the endogenous circadian clock appears to play a much more subdued role in growth regulation in Brachypodium, that has been demonstrated in either Arabidopsis, or crop plants like Rice, Corn and Soybean. This led to our conclusion that Brachypodium unfortunately is unlikely to serve as an informative model for understanding how growth regulation in plants is under the control of circadian network circuitry. However, we were able to leverage our datasets in Brachypodium to inform us and reinforce a large collaborative study on gene networks governing cell wall deposition in Arabidopsis. This led to a major and highly cited publication relevant to improving biomass production.

09 BIOMASS FUELS↗
DOE OSTI2017

Chapter 6: Residential Lighting Evaluation Protocol. The Uniform Methods Project: Methods for Determining Energy Efficiency Savings for Specific Measures

Given new regulations, increased complexity in the market, and the general shift from CFLs to LEDs, this evaluation protocol was updated in 2017 to shift the focus of the protocols toward LEDs and away from CFLs and to resolve evaluation uncertainties affecting residential lighting incentive programs.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2017

Radiative and Non-Radiative Pathways in InGaN Materials Heterostructures and Light-Emitting Diodes

Sandia National Laboratories (SNL) and Philips Lumileds Lighting Company, LLC (Lumileds) were to collaborate to better understand the physical properties of InGaN materials and heterostructures in radiative and non-radiative pathways of Light-Emitting Diodes (LEDs). SNL and Lumileds were to examine the influence of crystal defects on InGaN-based semiconductor LED efficiency and to characterize these crystal defects using deep level optical spectroscopy.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Final Report DOE SSL Grant (No. DE-EE0006673) Advanced Light Extraction Structure for OLED Lighting

The innovation proposed in this grant is to demonstrate a novel internal light extraction (ILE) design that can maximize the energy efficiency of Organic Light Emitting Diode (OLED) lighting devices without negatively impacting the device voltage, efficacy or angular color dependences. Even though, OLEDs have unique features compared to its inorganic counterparts, LEDs, in terms of technology development and market readiness levels, it still lags LEDs by several years. The main challenges as identified in the National Research Council’s 2013 Assessment on Solid State Lighting, are the cost of the materials and the low light extraction efficacy [1]. Improving the light extraction will improve both the $/Klm and lm/W, two important metrics DOE uses to measure the cost effectiveness of a light source.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2017

Integrated Plastic Substrates for OLED Lighting

OLED lighting has immense potential as aesthetically pleasing, energy-efficient general illumination. Unlike other light sources, such as incandescents, fluorescents, and inorganic LEDs, OLEDs naturally emit over a large-area surface. They are glare free, do not need to be shaded, and are cool to the touch, requiring no heatsink. The best efficiencies and lifetimes reported are on par with or better than current forms of illumination. However, the cost for OLED lighting remains high – so much so that these products are not market competitive and there is very low consumer demand. We believe that flexible, plastic-based devices will highlight the advantages of aesthetically-pleasing OLED lighting systems while paving the way for lowering both materials and manufacturing costs. These flexible devices require new development in substrate and support technology, which was the focus of the work reported here. The project team, led by Sinovia Technologies, has developed integrated plastic substrates to serve as supports for flexible OLED lighting. The substrates created in this project would enable large-area, flexible devices and are specified to perform three functions. They include a barrier to protect the OLED from moisture and oxygen-related degradation, a smooth, highly conductive transparent electrode to enable large-area device operation, and a light scattering layer to improve emission efficiency. Through the course of this project, integrated substrates were fabricated, characterized, evaluated for manufacturing feasibility and cost, and used in white OLED demonstrations to test their impact on flexible OLED lighting. Our integrated substrates meet or exceed the DOE specifications for barrier performance in water vapor and oxygen transport rates, as well as the transparency and conductivity of the anode film. We find that these integrated substrates can be manufactured in a completely roll-to-roll, high throughput process and have developed and demonstrated manufacturing methods that can produce thousands of feet of material without defects. We have evaluated the materials and manufacturing costs of these films at scale and find that they meet the current and future cost targets for bringing down the cost of OLED lighting while enabling future roll-to-roll manufacturing of the complete device. And finally, we have demonstrated that the inherent light-scattering properties of our films enhance white OLED emission efficiency from 20% to 50% depending on the metric. This work has shown that these substrates can be created, manufactured, and will perform as needed to enable flexible OLED lighting to enter the marketplace.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2017

Evaluation of Preventative Radiological/Nuclear Detector Archetypes to Validate Repurpose to the Consequence Management Mission

In the event of a radiological or nuclear emergency involving a large-scale release of radioactive material, local responders would be the primary means to perform radiation measurements to assess impacts and issue protective action recommendations for the responders and the public. Over the first 24-36 hours, Federal responders and resources will deploy to augment the local efforts, and if necessary, provide extensive radiation monitoring and assessment capabilities coordinated by the Department of Energy-led Federal Radiological Monitoring and Assessment Center and Federal Emergency Management Agency-led Multiagency Coordination Group. Unless Federal resources happen to be deployed at the moment an incident occurs, such as a preventative radiological/nuclear detection mission for a scheduled special event, the local response to an incident will commence and persist for many hours with no on-scene Federal support. For a catastrophic incident, such as a nuclear detonation or severe reactor accident, the local jurisdictions may not have a full range of adequate supplies of health physics instruments and personnel dosimetry. Therefore early in a crisis, the local responders will inevitably conduct their operations with the radiation detection and dosimetry capabilities that they have available until additional resources and support are requested and arrive. Most of the radiation detection instruments currently fielded at the local level are carried by law enforcement personnel and are designed for interdiction missions - referred to here as preventative radiological/nuclear detection (PRND) instruments. This study investigated how this PRND equipment can be repurposed in consequence management (CM) missions.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2017

Well Integrity for Natural Gas Storage in Depleted Reservoirs and Aquifers

Natural gas storage facilities are a critical component of our energy supply and distribution chain, allowing elasticity in gas supply to accommodate daily to seasonal demand fluctuations. As has been made evident by the recent Aliso Canyon Gas Storage facility incident, a loss of well integrity may result in significant consequences, including the prolonged shutdown of an entire facility. The Aliso Canyon gas well blowout emitted approximately 100,000 tonnes of natural gas (mostly methane) over 4 months and displaced thousands of nearby residents from their homes. The high visibility of the event has led to increased scrutiny of the safety of natural gas storage at the Aliso Canyon facility, led to questions about energy reliability, and raised broader concerns for natural gas storage integrity throughout the country.

03 NATURAL GAS↗
DOE OSTI2018

Photovoltaic Manufacturing Consortium (PVMC) – Enabling America’s Solar Revolution

The U.S. Photovoltaic Manufacturing Consortium (US-PVMC) is an industry-led consortium which was created with the mission to accelerate the research, development, manufacturing, field testing, commercialization, and deployment of next-generation solar photovoltaic technologies. Formed as part of the U.S. Department of Energy's (DOE) SunShot initiative, and headquartered in New York State, PVMC is managed by the State University of New York Polytechnic Institute (SUNY Poly) at the Colleges of Nanoscale Science and Engineering. PVMC is a hybrid of industry-led consortium and manufacturing development facility, with capabilities for collaborative and proprietary industry engagement. Through its technology development programs, advanced manufacturing development facilities, system demonstrations, and reliability and testing capabilities, PVMC has demonstrated itself to be a recognized proving ground for innovative solar technologies and system designs. PVMC comprises multiple locations, with the core manufacturing and deployment support activities conducted at the Solar Energy Development Center (SEDC), and the core Si wafering and metrology technologies being headed out of the University of Central Florida. The SEDC provides a pilot line for proof-of-concept prototyping, offering critical opportunities to demonstrate emerging concepts in PV manufacturing, such as evaluations of innovative materials, system components, and PV system designs. The facility, located in Halfmoon NY, encompasses 40,000 square feet of dedicated PV development space. The infrastructure and capabilities housed at PVMC includes PV system level testing at the Prototype Demonstration Facility (PDF), manufacturing scale cell & module fabrication at the Manufacturing Development Facility (MDF), cell and module testing, reliability equipment on its PV pilot line, all integrated with a PV performance database and analytical characterizations for PVMC and its partners test and commercial arrays. Additional development and deployment support are also housed at the SEDC, such as cost modeling and cost model based development activities for PV and thin film modules, components, and system level designs for reduced LCOE through lower installation hardware costs, labor reductions, soft costs and reduced operations and maintenance costs. The progression of the consortium activities started with infrastructure and capabilities build out focused on CIGS thin film photovoltaics, with a particular focus on flexible cell and module production. As marketplace changes and partners objectives shifted, the consortium shifted heavily towards deployment and market pull activities including Balance of System, cost modeling, and installation cost reduction efforts along with impacts to performance and DER operational costs. The consortium consisted of a wide array of PV supply chain companies from equipment and component suppliers through national developers and installers with a particular focus on commercial scale deployments (typically 25 to 2MW installations). With DOE funding ending after the fifth budget period, the advantages and disadvantages of such a consortium is detailed along with potential avenues for self-sustainability is reviewed.

14 SOLAR ENERGY↗
DOE OSTI2015

Public Preferences Related to Radioactive Waste Management Nuclear Energy and Environment: Methodology and Response Reference Report for the 2014 Energy and Environment Survey

The results described in this report are from nationwide surveys between 2006 and 2014 on preferences of US residents concerning the environment and energy sources. The most recent 2014 survey was undertaken to determine how consent, in the context of nuclear facility siting, is understood and evaluated by a cross-section of the American public. Continuing attention to the events at the Fukushima nuclear facility, coupled with its negative implications for public support for nuclear energy, has changed the balance of risk and benefit perceptions, and thus the context in which nuclear facility siting efforts will occur. In addition, the portion of the public most concerned about climate change have typically been those most concerned about the environment in general, and in turn, are those that have traditionally been hostile to nuclear energy. The overall survey results show that the broader public is not well informed about the nuclear fuel cycle including energy production from nuclear reactors and current policies for the management of used nuclear fuel. In addition, the surveys find that respondents are reluctant to continue to rely on temporary on-site storage of used nuclear fuel, and that there is moderate support for developing one or more interim storage facilities. The survey responses also suggest that the level of trust accorded a new nuclear waste authority by the public will be sensitive to how it is institutionally defined. For a hypothetical community, which had volunteered to host an interim storage facility within 50 miles of their homes, the majority of respondents indicated that veto authority in the siting process should be limited to (a) majorities of local and statewide voters, (b) state and federal environmental regulatory authorities, and (c) governors. The respondents also indicated that the state and local host community should be permitted to withdraw consent up to the point at which a license to build the facility is submitted, but not after the license is received and facility construction initiated. The 2013 and 2014 surveys posed a set of questions concerning respondents' expectations about engaging in the process for siting an interim storage facility. Roughly half of the respondents said they would likely attend informational meetings, and nearly half said they would likely communicate with elected officials or would likely express their views on the topic via social media. Relatively few -- about one in five -- said they would be likely to actively participate in support for or opposition of an ISF. Finally, the 2014 results suggest that while respondents are more likely to support a citizen-led deliberative panel process than one led by experts, this preference does not seem to influence their opinion about the expected outcome of the siting process.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

Advanced Fuels Campaign 2017 Accomplishments

AFC management and integration activities in FY-17 included continued support for international collaborations, primarily with France, Japan, the European Union, Republic of Korea, and China, as well as various working group and expert group activities in the Organization for Economic Cooperation and Development Nuclear Energy Agency (OECD-NEA) and the International Atomic Energy Agency (IAEA). Three industry-led Funding Opportunity Announcements (FOAs) and two university-led Integrated Research Projects (IRPs) funded in 2013, made significant progress in fuels and materials development. All are closely integrated with AFC and accident-tolerant fuels (ATF) research. Accomplishments made during FY-17 are highlighted in this report, which focuses on completed work and results.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2018

A Search for Large Extra Dimensions with MINOS and MINOS+

This dissertation presents the search for large extra dimensions using the rich and unique accelerator beam neutrino data collected by the MINOS and MINOS+ experiments from 2005 to 2012 and 2013 to 2016, respectively. Most data from neutrino oscillation experiments are consistent with the standard three-flavor paradigm. With increasing experimental precision, potential effects from physics beyond the Standard Model that could modify neutrino oscillations in subtle ways can be explored. One such scenario involves additional spatial dimensions. Following the Large Extra Dimensions (LED) model, sterile neutrinos arising as Kaluza-Klein states in an extra dimension with size R can mix with the three active neutrinos in 3+1 spacetime, thereby altering the neutrino oscillation probabilities. In addition, this model provides a natural explanation for small Dirac neutrino masses through mass suppression by the volume of the large extra dimensions. In this work, two analysis strategie s are employed to search for large extra dimensions: the Far-over-Near analysis and the two-detector analysis. In the former, the ratio of the neutrino energy spectra measured in the MINOS Far and Near Detectors is used to constrain the LED model parameters, while in the latter the measured spectra are used simultaneously. MINOS reported the strongest constraint on R from a neutrino oscillation experiment, constraining R to be smaller than $0.45\,\mu\text{m}$ at 90\% C.L. in the limit of a vanishing lightest neutrino mass, using the Far-over-Near approach. Including MINOS+ data, which significantly increases the number of events at higher neutrino energies away from the three-flavor minimum where the model effects are larger, and using the two-detector technique, the size of extra dimensions is further constrained to be smaller than $0.30\,\mu\text{m}$ at 90\% C.L. Stronger limits are obtained for non-vanishing lightest neutrino masses.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗