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At least 19 records

Artificial Intelligence/Deep Learning FRNN Software for Prediction & Real-Time Control of DIII-D Plasma Control System (PCS)

This collaborative project integrated an improved version of the Artificial Intelligence/Deep Learning FRNN prediction and control software into the real-time DIII-D PCS (plasma control system). A key AI/DL software challenge is to build a modern high-performance computing (HPC) enabled “synthetic plasma simulator” capable of carrying out HPC-driven real-time plasma control applications. This involves development of a deep learning framework to train the surrogate model for a first-principles-based instability analysis simulator (“SGTC”) derived from the global gyrokinetic code GTC. The role of SGTC is to provide accurate and detailed plasma instability information from a real-time AI-based simulator capability to complement the deep learning prediction and control from experimentally-measured signals, such as ECE Imaging, supplemented by synthetic SGTC-ECEI.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Insight Into Sulfur‐Containing Additive to Boost Anti‐Oxidation Ability of the Ether‐Based Electrolyte for Sodium‐Ion Full Batteries

Ether-based electrolytes are considered as promising candidates for sodium-ion batteries (SIBs) due to their high ionic conductivity and good compatibility with hard carbon (HC) anode. However, they suffer from poor anti-oxidative ability with unstable cathode electrolyte interface, inducing successive electrolyte decomposition and rapid capacity fading. Herein, the sulfur-containing additive (1,3-propanediol cyclic sulfate, PCS) is introduced to boost the stability of the electrode-electrolyte interface (EEI) in ether-based electrolyte. PCS largely participates in the inner Na + sheath, causing more diglyme (G2) molecules and fewer PF 6 - anions to occupy the inner Na + solvation sheath, avoiding the decomposition of G2 molecules at high operation voltage. Moreover, PCS is beneficial for simultaneously constructing thin and robust sulfur-containing EEI on both Prussian blue (PB) cathode and HC anode, maintaining the structural stability of PB and alleviating the dissolution of transition metals. These enable PB||HC pouch cells to deliver a capacity retention of 60.3% after 400 cycles, significantly higher than the 32.1% in PCS-free electrolytes. In conclusion, this work discloses the underlying mechanism of PCS to evoke the anti-oxidation ability of ether-based electrolyte and provides a promising method for realizing advanced sodium-ion full cells.

anti-oxidation ability

Enhanced Interfacial Strength in Carbon Fiber Composites via Mussel‐Inspired Sizing Polymers

Composite materials possess a high strength-to-weight ratio. A key determinant of their mechanical performance is the interfacial strength between the fibers and the matrix. Sizing agents are commonly used to improve this interface by promoting better adhesion, though optimizing this interaction remains a significant challenge. Here, this study evaluates the use of poly(catechol-styrene) (PCS), a mussel-inspired sizing agent, to enhance fiber–matrix bonding in carbon fiber composites. Woven carbon fiber laminates were dip-coated with varying concentrations of PCS (0.05 and 0.1 wt%) and subsequently fabricated using vacuum-assisted resin transfer molding followed by compression molding. Interlaminar shear strength (ILSS) tests showed improvements of 4% and 8% for the 0.05% and 0.1% PCS treatments, respectively. These results indicate that PCS is effective in reinforcing interfacial adhesion, thereby improving the mechanical integrity of carbon fiber-reinforced composites.

Carbon fiber composites

Preliminary proof-of-concept of real-time divertor heat flux control from infrared cameras with nitrogen injection in the DIII-D tokamak

In future tokamak reactors like ITER and the Fusion Pilot Plant (FPP), real-time feedback control of heat flux to the plasma-facing components (PFC) will be critical for steady-state operation. This work presents the first experimental demonstration of real-time divertor heat flux estimation with infrared thermography and feedback control with impurity seeding on the DIII-D tokamak. The flexible infrastructure of the Plasma Control System (PCS) on DIII-D makes this new capability possible. The PCS software runs on a gateway computer system, and five real-time compute nodes. An array of low latency streaming digitizers from D-TACQ Solutions connects to these real-time computers to collect and process data, and send commands to actuators during plasma discharges. This system handles the signal IO from the tokamak and allows the PCS to utilize the diagnostic data necessary to perform control in real-time. Feedback control on heat flux was accomplished by feeding infrared camera data from the “Infrared TV” (IRTV) camera to a custom-developed User Datagram Protocol (UDP) server. This server transmits infrared data to a newly developed PCS algorithm that estimates the heat flux to PFC. Here, a proportional integral derivative (PID) controller minimizes the error between a heat flux reference and the real-time estimate by injecting nitrogen gas into the divertor.

Algorithm development

Cerebellar dysfunction in a mouse model of childhood-onset manganese-induced dystonia parkinsonism

Humans with pathogenic variants of the manganese (Mn) transporter gene SLC39A14 exhibit highly elevated brain Mn concentrations and childhood-onset dystonia-parkinsonism. Here we show that Slc39a14-knockout (KO) mice, a preclinical model of the disease with elevated Mn concentrations in the CB, express deficits in physiological tremor implicating cerebellar (CB) dysfunction. Imaging of intracellular Mn in Purkinje cells (PCs) using synchrotron-based X-ray fluorescence microscopy confirmed highly elevated Mn concentrations in the PCs of Slc39a14-KO mice. To determine biological pathways altered in the CB of Slc39a14-KO mice relative to wildtype (WT), we performed RNA sequencing and discovered significant upregulation of pathways and genes regulating immune response and cell death. To substantiate these findings, we performed quantitative autoradiography of the neuroinflammation biomarker Translocator Protein 18 kDa (TSPO) which was significantly increased in the CB of Slc39a14-KO mice relative to WT. The latter findings were confirmed via immunostaining with the microglial marker Iba-1, revealing widespread microglia activation and clustering in the CB cortex. Immunostaining for cleaved caspase-3 (cCASP3), a marker of apoptosis, showed increased number of PCs with positive immunolabeling for cCASP3 in Slc39a14-KO mice relative to WT. Degeneration of PCs was confirmed by Hematoxylin and Eosin (H&E) staining. Lastly, functional electrophysiological assessment of CB neurocircuitry revealed a marked decrease in firing rates of cerebellar nuclei (CN) neurons and increased variability of PC simple spikes firing. Collectively, these findings show, for the first time, Mn-induced PC degeneration and dysfunctional CB circuitry in Slc39a14-KO mice providing additional evidence for the pathological underpinnings of the dystonia-like movements, balance, and gait abnormalities in SLC39A14 mutation carriers.

36 MATERIALS SCIENCE

Structural Design and Modeling of MARVEL Primary Coolant System Using the ASME Section III, Division 5, Code

This paper presents the structural design and supporting analysis for the Microreactor Applications Research Validation and Evaluation (MARVEL) primary coolant system (PCS) using the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Section III, Division 5, rules. MARVEL is a liquid metal–cooled microreactor intended to provide experimental capabilities for the rapid testing and development of microreactor technologies. The PCS utilizes high-temperature sodium-potassium liquid metal as the primary coolant and operates at a design temperature of 570°C, necessitating the consideration of creep-related failure mechanisms. The base metal for the PCS is 316H stainless steel, and the weldments are made with a 16-8-2 filler. The design approach incorporates the current base code rules along with ASME code cases N-924, N-861, and N-862 to address primary load, ratcheting, and creep-fatigue evaluations, respectively. The reactor’s operation involves complex thermal and mechanical interactions due to natural convective flow and differential thermal expansion between components. In conclusion, this paper discusses the structural engineering challenges encountered, such as managing thermal stresses in the distribution plenum and guard vessel, and outlines the strategies implemented to meet the code requirements, including design modifications and operational constraints.

21 - SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLAN

Ultra-thin photonic crystal slab metalenses [Invited]

We report a novel ultra-thin metalens design based on photonic crystal slab (PCS) resonance modes. We experimentally verified with a metalens structure based on amorphous silicon on a quartz material platform by implementing the optical guided resonance on the PCS. The PCS metalens designs feature an ultra-thin device layer of about 160 nm at an operation wavelength of 940 nm. A full 2π transmission phase transition is realized by varying the air hole sizes at the design wavelength. Metalens devices with different phase change gradients were designed and fabricated to achieve different NAs. A maximum of 86.4% focusing efficiency is achieved. Imaging capabilities are characterized, and clear images are observed within the field of view. The PC resonance-based phase modulation design can be applied to optical beam manipulation, phase plate design, imaging, and laser beam formation applications.

77 NANOSCIENCE AND NANOTECHNOLOGY

Operational Experience and Development of a Reliability Model for the ATR Demineralizer System (Slides)

The Advanced Test Reactor (ATR) is a light water reactor with aluminum clad driver fuel. Strict limits are implemented on pH, conductivity, and filterable solids to assure the performance of the driver fuel limit corrosion of the primary coolant system (PCS) pressure boundary components. A bypass demineralizer system is used to maintain PCS coolant within allowable bands for each of the aforementioned variables. Unlike many other reactors, the ATR does not have a filtration system. As such, failure of ion exchange resin in the bypass demineralizer can defeat the purpose of the system and result in high filterable solids in the PCS. Power operations with high filterable solids is prohibited by a technical safety requirement. This paper discusses recent failures of the ATR bypass demineralizer system. The testing and analysis done to deduce the cause of the failures is covered, as well as short term mitigative steps that were taken. To prevent the likelihood of future issues, historical data from the ATR and industry is used to develop a reliability model of the ATR bypass demineralizer system. Evidence of radiolytic decomposition of ion exchange resin was found in the cause investigation. As such, special attention is given to ion exchange resin failure due to high radiation environments. The reliability model is used to develop the ATR testing and maintenance program. Specifically, limits on resin service life are discussed.

21 - SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLAN

A prototype cooling blanket for mitigating occupant overheating risk in a hot indoor environment: Modeling and assessments

Conventional ways of cooling a room or an entire house for occupant thermal comfort during summer consume a significant amount of energy and are vulnerable to overheating risk during power outages that lead to loss of cooling system operations. This study investigates a low-power cooling blanket, as a Personal Cooling System (PCS), that covers the upper human body for direct cooling during a five-day heat wave in a single-family house. A modeling framework is developed for evaluating the thermal and energy performance of the cooling blanket, which builds upon the co-simulation of three models: a house energy model, a personal thermal comfort model, and a cooling blanket model. Simulation results show that under the power outage scenario, the cooling blanket can greatly reduce the occupant heat stress with a reduction of daily hours of exceedance (discomfort hours defined as TSV>2) by up to 17.2 h (a 95.3 % improvement from the baseline power outage without the blanket). The cooling blanket, equipped with an innovative electrocaloric heat pump (COP as high as 10.1) consumes 6.31 W and can be operated by a portable battery for several days. The cooling blanket consumes only 0.28 % of the electricity of a central air-conditioning system running to provide cooling for the whole house during the five-day heatwave period. The findings justify further research of electrocaloric wearable PCS as low-power effective cooling to ensure thermal survivability of occupants during extreme indoor environments.

Electrocaloric heat pump

How Cloud is Accelerating Research at NREL

This presentation coincides with AWS's announcement of their new Parallel Computing Service (PCS) which allows for easy creation of HPC-style clusters in their AWS cloud computing platform. I helped them beta test this service before it was made generally available in August. AWS asked if we would be interested in discussing our experience with the PCS service, and our experience with HPC workloads in the cloud in general, so this slideshow discusses a brief history of scientific computing at NREL and shares a bit of our experiences and approach to utilizing cloud services for HPC-style workloads.

97 MATHEMATICS AND COMPUTING

B‐Staging and Crosslinking of Polycarbosilane at Room Temperature: Cure Mechanism and Properties

The viscosity of polycarbosilane (PCS) polymers is not advantageous for free forming. Various fillers and heat are used to obtain a formable paste. Due to the low yield stress, structures and preforms tend to slump or resin will flow out, especially during the curing of the polymer. B-staging of PCS allows for a more stable structure from room temperature until the full cure of the allyl groups occurs with heat. Additionally, hydrosilation is an effective means of crosslinking at room temperature and controlling viscosity. A network structure was formed in SMP-10 using silane and a vinyl-based crosslinker to bridge each polymer chain. Pt addition catalysts were added to enhance the increase in viscosity to make a lightly crosslinked gel to aid in thickening and forming and to improve the ceramic yield at 1000°C. In conclusion, this enables several options for controlling rheology and improving the properties of preceramic polymers to avoid slumping during curing.

inorganic polymers

405 nm violet-blue light inactivates hepatitis C cell culture virus (HCVcc) in ex vivo human platelet concentrates and plasma

Abstract Added safety measures coupled with the development and use of pathogen reduction technologies (PRT) significantly reduces the risk of transfusion-transmitted infections (TTIs) from blood products. Current approved PRTs utilize chemical and/or UV-light based inactivation methods. While the effectiveness of these PRTs in reducing pathogens are well documented, these can cause tolerable yet unintended consequences on the quality and efficacy of the transfusion products. As an alternative to UV-based approaches, we have previously demonstrated that 405 nm violet-blue light exposure successfully inactivates a variety of pathogens, including bacteria, parasites, and viruses, in both platelet concentrates (PCs) and plasma. Herein, we show that 405 nm light treatment effectively inactivates hepatitis C cell culture virus (HCVcc) by up to ~ 3.8 log10 in small volumes of a variety of matrices, such as cell culture media, PBS, plasma, and PCs with 27 J/cm 2 of light exposure, and total inactivation of HCVcc after 162 J/cm 2 light exposure. Furthermore, we demonstrate that carry-over of media supplemented with fetal bovine serum enhances the production of reactive oxygen species (ROS), providing mechanistic insights to 405 nm light-mediated viral inactivation. Overall, 405 nm light successfully inactivates HCVcc, further strengthening this method as a novel PRT for platelets and plasma.

Science & Technology - Other Topics

Framework for assessment of magnetic equilibrium controller performance on the MAST upgrade spherical tokamak

Here, in this work we present the assessment framework for magnetic equilibrium controllers on MAST Upgrade spherical tokamak (MAST-U) spherical tokamak. Such controllers are essential for the MAST-U since exhaust physics and core-edge integration studies require advanced divertor plasma configurations. The developed framework is based on the TokSys suite of plasma control codes, which was adapted and upgraded for MAST-U. However, extra capabilities were added on top of TokSys to support the development of new control algorithms, deployment of controllers to the plasma control system (PCS) and evaluation of their performance. The controller assessment was realized via closed-loop integrated control simulations with the actual MAST-U PCS and different physics-based plasma models. Since all components of the assessment chain were experimentally validated, these simulations provide qualified controllers applicable for direct use in the experiment. This resulted in the successful experimental demonstration of advanced plasma shape control on MAST-U with minimal on-machine development time. A similar methodology would be beneficial to other tokamaks, both existing and future.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Experimental demonstration of real-time electron temperature profile control in DIII-D

Future tokamak reactor operation will require the ability to maintain a given plasma scenario for extended periods of time. This will necessitate the capability to react to changes in the plasma state and return the plasma to the target scenario; the principal method to achieve this is through feedback control. Thus, it is necessary to develop and test feedback controllers for the plasma profiles that define a target scenario. In this work, a feedback controller for the electron temperature (Te) profile is tested experimentally in DIII-D. This experiment relied on the ability to ascertain the electron temperature profile in real time, which was achieved using an observer algorithm. The observer relies on both diagnostic data and a predictive model of the electron temperature profile evolution; this predictive model includes contributions from neural network surrogate models. Because of these dependencies, a number of capabilities needed to be added to the real-time PCS for DIII-D in order to support the Te profile control experiment. The neural network surrogates needed to be integrated into the PCS to be called in real time. An observer algorithm for the Te profile needed to be added and connected to the Thomson scattering system to allow access to the current state of the profile in real time. When tested, the observer was shown to produce Te profiles that are consistent with the shape of the Thomson scattering data while rejecting much of the noise in the diagnostic data. Finally, the controller itself was tested in real time. This experiment showed that the controller is capable of tracking the electron temperature target at locations across the spatial profile.

Morosohk, Shira [Oak Ridge Associated Universities

ECAR-8446 Rev 0 MARVEL BPVC Section III Division 5 HBB Fatigue Acceptance Tests

The objective of this analysis is to evaluate the fatigue and creep behavior of 316 SS materials used in the Primary Coolant System (PCS) and Guard Vessel System (GVS) for the first two years of MARVEL reactor operation. The analysis follows the requirements set forth in ASME BPVC Section III, Division 5, HBB-2800, which mandates a fatigue test if operational conditions exceed allowable thresholds. By determining whether the materials meet the HBB-T-1324(a) and HBB-T-1324(b) criteria, this evaluation establishes whether a fatigue test is necessary, as well as the maximum allowable operational hours and temperatures before fatigue testing would be required. The deliverables of this analysis include calculations validating compliance with fatigue acceptance criteria, determination of maximum operational limits for the two-year period, and identification of conditions under which a fatigue test would be necessary. This ensures that the PCS and GVS can operate safely without premature material degradation and align with the design life requirements outlined in SPC-70731. Additionally, this evaluation provides conservative estimates for Service Level B occurrences and their impact on allowable Service Level A hours and temperatures, offering guidance for future operational assessments and potential life extensions beyond the initial two-year period.

21 - SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLAN

ECAR-8848 Rev 2 MARVEL Primary Coolant System Lifting Analysis

The objective of this ECAR is to perform a lifting analysis of the Microreactor Applications Research Validation and Evaluation (MARVEL) Primary Coolant System (PCS) vertically, pickup from horizontal, the temporary lifting plate, and spreader.

21 - SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLAN

Implementation of high-speed data acquisition at DIII-D

Research at the DIII-D National Fusion Facility in San Diego focuses on short pulse plasma discharges that specialize on various shaping profiles. High-speed data collection is a critical component for the operation of many of DIII-D’s diagnostics and is fundamental for capturing high-resolution data used in experimental data analysis. Differing techniques enable the plasma control system (PCS) to perform complex real-time feedback control on microsecond time scales. This work presents a comprehensive overview of data acquisition, focusing on the hardware and software used in reliable data acquisition at DIII-D. The robust nature of the data acquisition system allows for various techniques to coexist seamlessly. However, as modern systems capable of nanosecond resolution become more common, existing architectures will need to be modified. Here, by addressing the key challenges of high-speed data acquisition, DIII-D is able to provide real-time data used in plasma operation and has the ability to acquire high fidelity data needed for future experimental fusion reactors, such as ITER.

Control