SEARCH · Engineering Papers
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
The production of reactor-based medical isotopes is fragile, which has meant supply shortages from time to time. This paper reviews alternative production methods in the form of cyclotrons, linear accelerators and neutron generators. Finally, the status of the production of medical isotopes in China is described.
Early fault detection and fault prognosis are crucial to ensure efficient and safe operations of complex engineering systems such as the Spallation Neutron Source (SNS) and its power electronics (high voltage converter modulators). Following an advanced experimental facility setup that mimics SNS operating conditions, the authors successfully conducted 21 early fault detection experiments, where fault precursors are introduced in the system to a degree enough to cause degradation in the waveform signals, but not enough to reach a real fault. Nine different machine learning techniques based on ensemble trees, convolutional neural networks, support vector machines, and hierarchical voting ensembles are proposed to detect the fault precursors. Although all 9 models have shown a perfect and identical performance during the training and testing phase, the performance of most models has decreased in the next test phase once they got exposed to realworld data from the 21 experiments. The hierarchical voting ensemble, which features multiple layers of diverse models, maintains a distinguished performance in early detection of the fault precursors with 95% success rate (20/21 tests), followed by adaboost and extremely randomized trees with 52% and 48% success rates, respectively. The support vector machine models were the worst with only 24% success rate (5/21 tests). The study concluded that a successful implementation of machine learning in the SNS or particle accelerator power systems would require a major upgrade in the controller and the data acquisition system to facilitate streaming and handling big data for the machine learning models. In addition, this study shows that the best performing models were diverse and based on the ensemble concept to reduce the bias and hyperparameter sensitivity of individual models.
Developing breakthroughs in accelerator science and translating them into applications for the nation’s health, wealth and security.
Fermilab’s Proton Improvement Plan II will power the long-term future of the U.S. accelerator-based particle physics program and enable the world’s most powerful high-energy neutrino beamfor the international Deep Underground Neutrino Experiment.
Unprecedented $\rm TeVm^{-1}$ acceleration gradients are modeled to be realizable using a nonlinear surface crunch-in mode in nanostructured tubes. This mode is realizable using advances in nanofabrication and solid energy density attosecond bunch compression. Three dimensional computational and analytical modeling demonstrates GeV energy gain in sub-millimeter long tubes with effective wall densities $n_{\rm t}\sim10^{22-24}\rm cm^{-3}$ and hundreds of nanometer core radius when driven by submicron near solid electron beams, $n_{\rm b}\sim0.05n_{\rm t}$. Besides the many $\rm TVm^{-1}$ average gradients, strong self-focusing and nanomodulation of the beam which increases its peak density and the wakefield strength also opens up controlled high-energy photon production.
Fermilab’s Proton Improvement Plan II will power the long-term future of the U.S. accelerator-based particle physics program and enable the world’s most powerful high-energy neutrino beam for the international Deep Underground Neutrino Experiment.
Coherent transverse oscillations of a bunch in a ring accelerator are considered. Three different models of the bunch are used: a hollow bunch in a square potential well, a square bunch in a parabolic potential well, and a parabolic bunch in a parabolic well. The bunch space-charge field, wakefield, and chromaticity are taken into account in all the cases. The bunch eigenmodes and various instabilities are studied. The results are compared and analyzed to establish the range of applicability of the models. Role of the Landau damping due to dependence of the SC field on the longitudinal coordinate is discussed.
The chapter develops the formalism for the two-dimensional representation of the fields which are commonly found in accelerator magnets. The chapter describes the sense windings and associated components used in the precise measurement of these fields.
NREL helps translate community energy ambitions into actions. Rooted in inclusive community engagement, Accelerating Clean Energy @ Scale (ACES) brings together NREL’s experience, expertise, and capabilities to illuminate pathways for clean, affordable, equitable, secure, and resilient energy systems. Through customized, holistic modeling and analysis, we uncover insights and collaboratively develop strategies that address communities’ unique energy- system goals and diverse stakeholder priorities. NREL provides support in evaluating and implementing community-selected options, as well as assistance for workforce development.
The Booster Operation Optimization Sequential Time-series for Regression (BOOSTR) dataset was created to provide a cycle-by-cycle time series of readings and settings from instruments and controllable devices of the Booster, Fermilab's Rapid-Cycling Synchrotron (RCS) operating at 15~Hz. BOOSTR provides a time series from 55 device readings and settings that pertain most directly to the high-precision regulation of the Booster's gradient magnet power supply (GMPS). To our knowledge, this is one of the first well-documented datasets of accelerator device parameters made publicly available. We are releasing it in the hopes that it can be used to demonstrate aspects of artificial intelligence for advanced control systems, such as reinforcement learning and autonomous anomaly detection.
A method and system for in situ cross-linking of polymers, Bitumen, and other materials to produce arbitrary functional or ornamental three-dimensional features using electron beams provided by mobile accelerators comprises defining a desired pattern for imparting on a target area, mapping the target area, defining at least one discrete voxel in the target area according to the desired pattern to be imparted on the target area, assigning an irradiation value to each of the at least one discrete voxels, and delivering a dose of irradiation to each of the at least one discrete voxels according to the assigned irradiation value.
Fermilab is developing a compact superconducting (CSRF) accelerator as a source of a high-power, high-energy electron beam to produce an x-ray beam comparable to $\geq$ 2 MCi of cobalt-60. As part of this development, we are presently assembling a 20 kW, 1.6 MeV prototype that incorporates the four enabling technologies described below. These technologies support a heat budget that is within the capacity of commercially available cryocoolers and eliminate the need for liquid cryogens. The use of superconducting technologies promises efficiencies, wall-plug to beam, of 80% or greater. A summary of the design and progress to date will be given. In addition, we will present a review of developments within the medical device sterilization industry that are motivating the development of this technology.
The Snowmass community exercise started in April 2020 to identify and document a scientific vision for the future of particle physics in the US and international partners. The AF7-Magnets working group was charged to a) address the potential contributions of magnet technology to future HEP facilities, b) evaluate the R&D required to enable these opportunities, c) estimate the time and cost scales of these efforts, and d) assess the needs for associated fabrication infrastructure and test facilities. This report addresses the working group charge, summarizes the status of accelerator and detector magnet technologies, and discuss ideas and plans to push this key area of the US and international HEP to new horizons.
The purpose of this report is to begin the development of a maximally efficient process for licensing and deploying new materials in Advanced Non-Light-Water Reactors (ANLWRs). Some new materials that are to be used in some new plants are seen as possibly introducing risks, because our understanding of those new materials’ behavior in the conditions generated by some novel plant designs is less complete than our understanding of the behavior of materials with long use histories in existing designs. In these cases, an approved code/standard or a code case to support the use of these materials in the novel design’s safety case may not exist for the regulator to utilize as part of the licensing determination. This circumstance creates the potential for an extremely long licensing process for new designs using new materials. The present strategy is to show how to manage these risks proactively, in such a way as to permit licensing decisions to be made in a timely manner, based on this risk management process. The present report outlines the gaps in the current codes to support deployment and use of novel materials and begins the development of the necessary risk management framework that is focused on the subject materials issues; it is based on risk-informed in-service surveillance practices, carried out in such a way as to compensate for current limitations in our state of knowledge. This development will enable licensing and deployment of the subject materials, conditional on the proactive surveillance process to be established. While this report is occasioned by limitations in our knowledge of certain materials issues that may arise in advanced designs, in-service surveillance is always done in order to compensate for a lack of knowledge: if we knew that components were not already failed and not trending toward failure, we would not perform surveillance, even in current-generation plants (except that prescriptive requirements would force us to do so). What is different about the surveillance program discussed here is that the issues are newer and the relevant experience base is less complete, so the surveillance presently contemplated may need to measure new things and/or measure them more often than has been traditional for surveillance coupons. The present report is devoted to the risk management framework and applies American Society of Mechanical Engineers Boiler and Pressure Vessel Code Section XI, Division [1] to establish the structure of a protocol for carrying out the necessary surveillance. These documents are generic: they do not tell us how often to surveille, or what to surveille, or what to measure, but rather how to determine those things, given certain technical inputs. The Regulatory Development R&D Program [2] is currently developing the companion supporting technical basis for the materials surveillance technology that, when completed and validated, can be used by owner/operator and NRC to implement a materials degradation management program for ANLWRs. This report also outlines salient points of discussion, positive potential outcomes, and potential concerns from industry and the USNRC. These aspects of the report intend to inform future work to develop a proposed technical process for adoption by the industry and endorsement by the USNRC to allow developers to propose a risk informed and conservative approach for the use of materials where operating experience/data and codes and standards may not exist for use of a novel material in an operating reactor environment. Additionally, such a technology could be leveraged to potentially reduce part of the upfront materials data requirements from ongoing long-term materials testing so that early action on license application could be undertaken by NRC, in parallel with the continuation of long-term data collection. This could accelerate the schedule for a first-of-a-kind ANLWR deployment or a nth-of-a-kind new materials insertion for established ANLWR designs.
Dear author, This is a reminder that we are expecting you to resubmit your IPAC'23 paper 1268 at https://indico.jacow.org/event/41/papers/2549/ in a format compliant with the IoP guidelines posted at https://publishingsupport.iopscience.iop.org/author-guidelines-for-conference-proceedings/ Could you please upload your paper as a PDF file in the IoP format at https://indico.jacow.org/event/41/papers/2549/ Title: The Design of the Emittance Diagnostic for the Scorpius Accelerator id: 1268 The deadline for resubmitting your paper is July 1st 2023 but we would appreciate if you could submit it earlier. Thank you in advance, Nicolas Delerue on behalf of the IPAC'23 LPR SPB
Two CEBAF 5-cell accelerator cavities have been coated with Nb3Sn film using the vapor diffusion technique. One cavity was coated in the Jefferson Lab Nb3Sn cavity coating system, and the other in the Fermilab Nb3Sn coating system. Both cavities were measured at 4 K and 2 K in the vertical dewar test in each lab and then assembled into a cavity pair at Jefferson Lab. Previous attempts to assemble Nb3Sn cavities into a cavity pair degraded the superconducting properties of Nb3Sn-coated cavities. This contribution discusses the efforts to identify and mitigate the pair assembly challenges and will present the results of the vertical tests before and after pair assembly. Notably, one of the cavities reached the highest gradient above 80 mT in the vertical test after the pair assembly.
A 218 MHz quarter wave niobium cavity has been fabricated for the purpose of demonstrating Nb3Sn technology on a low-beta accelerator cavity. Niobiumtin has been established as a promising next generation SRF material, but development has focused primarily in high-beta elliptical cell cavities. This material has a significantly higher TC than niobium, allowing for design of higher frequency quarter wave cavities (that are subsequently smaller) as well as for significantly lowered cooling requirements (possibly leading to cryocooler based designs). The fabrication, initial cold testing, and Nb3Sn coating are discussed as well as test plans and details of future applications.
While further understanding is sought, the results suggest that a module can show no degradation in performance through a qualification test light soak, (IEC 61215: 2021 MQT 19.1 requirement of 10 kW minimum on one side). Yet, such cells may degrade significantly by LID under conditions within the statistical extremes of the natural environment applied in combined-accelerated stress testing (CAST).