Search NASA⌕ Search

SEARCH · Search NASA

Results for “Accelerator Applications”

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.

At least 685 records · Page 38
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Accelerator Reactor Coupling for Energy Production in Advanced Nuclear Fuel Cycles

This article is a review of several accelerator–reactor interface issues and nuclear fuel cycle applications of acceleratordriven subcritical systems. The systems considered here have the primary goal of energy production, but that goal is accomplished via a specific application in various proposed nuclear fuel cycles, such as breed-and-burn of fertile material or burning of transuranic material. Several basic principles are reviewed, starting from the proton beam window including the target, blanket, reactor core, and up to the fuel cycle. We focus on issues of interest, such as the impact of the energy required to run the accelerator and associated systems on the potential electricity delivered to the grid. Accelerator-driven systems feature many of the constraints and issues associated with critical reactors, with the added challenges of subcritical operation and coupling to an accelerator. Reliable accelerator operation and avoidance of beam trips are critically important. One interesting challenge is measurement of blanket subcriticality level during operation. We also review the potential benefits of accelerator-driven systems in various nuclear fuel cycle applications. Ultimately, accelerator-driven subcritical systems with the goal of transmutation of transuranic material have lower 100,000-year radioactivity than a critical fast reactor with recycling of uranium and plutonium.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2025

Elliptic Aperture CCT Coils for HTS Dipole Magnets

High-temperature REBa$_{2}$Cu$_{3}$O$_{7-x}$ (REBCO) superconductors are a route to increase the field of accelerator magnets beyond the 15-16T practical limit of Nb$_{3}$Sn. REBCO cabled in a CORC geometry is a promising fit for this application, enabling the design of low inductance magnets with conductor transposition. However, the use of CORC in coils with the tight conductor bending radii typical of accelerator magnets remains a key challenge, with on-going research both on the conductor development and coil design fronts seeking to address this issue. Here, in this work we explore the tradeoffs between circular and elliptic aperture canted-cosine-theta (CCT) coils when the conductor minimum bending radius is a key consideration, concluding that aperture ellipticity is an important free parameter in the optimization of magnetically efficient CORC dipole magnets. In particular, we show that elliptic bore designs enable a regime of smaller aperture HTS coils, an important result for LTS-HTS hybrid magnets and more generally for accelerator applications benefiting from non-circular magnet apertures. To this end we present an elliptic aperture dipole design optimized for hybrid testing within the US Magnet Development Program (US-MDP) and share 77 K test results of a prototype coil which provides first experimental confirmation of the advantages.

Brouwer, L. [Lawrence Berkeley National Laboratory↗
DOE OSTI2020

Advanced Accelerator Technology (Final Report)

Superconducting radio-frequency (SRF) acceleration, together with high precision RF field control and high precision beam instrumentation and control, is a key technology for future next generation accelerators. In the past 10 years, significant progress on these technologies has been made jointly at KEK and US laboratories. The research progress summarized here is Cornell University’s contribution to a continued US-Japan collaborative accelerator research effort. The combined objectives of this collaboration were to solve critical technical issues related to SRF acceleration technology, related to low emittance beam generation, and related to reducing the vertical beam size of the ATF2 final focus beam line. These joint efforts significantly advance current accelerator technologies. The specific objective of the Cornell University part of this collaboration was to develop, in close connection with KEK and FNAL, new SRF cavity Nb3Sn thin-film coating technologies for transformational cavity performance. Cornell is a world leader in the synthesis of Nb3Sn for SRF application, and has produced the first-ever next-generation non-niobium (i.e., Nb 3 Sn) prototype SRF accelerator cavities with cryogenic efficiency exceeding that of traditional niobium cavities. These next-generation Nb 3 Sn SRF cavities strongly reduce AC power consumption of SRF based accelerators, and also enable using greatly simplified cryogenic cooling infrastructure, thereby making SRF technology available to a much wider range of accelerator applications. During this project, Cornell has designed and started fabrication of a new Nb 3 Sn coating setup, which will be large enough to coat full-scale (i.e., multi-cell) SRF accelerator cavities. In addition, Cornell University has participated in other collaborative activities at KEK and partner US laboratories.

43 PARTICLE ACCELERATORS↗
NASA NTRS2008

Cherenkov and Scintillation Properties of Cubic Zirconium

Cubic zirconium (CZ) is a high index of refraction (n =2.17) material that we have investigated for Cherenkov counter applications. Laboratory and proton accelerator tests of an 18cc sample of CZ show that the expected fast Cherenkov response is accompanied by a longer scintillation component that can be separated by pulse shaping. This presents the possibility of novel particle spectrometers which exploits both properties of CZ. Other high index materials being examined for Cherenkov applications will be discussed. Results from laboratory tests and an accelerator exposure will be presented and a potential application in solar energetic particle instruments will be discussed

Christl, M.J.↗
DOE OSTI2015

Efficient quasi-monoenergetic ion beams from laser-driven relativistic plasmas

Table-top laser–plasma ion accelerators have many exciting applications, many of which require ion beams with simultaneous narrow energy spread and high conversion efficiency. However, achieving these requirements has been elusive. We report the experimental demonstration of laser-driven ion beams with narrow energy spread and energies up to 18 MeV per nucleon and ~5% conversion efficiency (that is 4 J out of 80-J laser). Using computer simulations we identify a self-organizing scheme that reduces the ion energy spread after the laser exits the plasma through persisting self-generated plasma electric (~1012 V m -1 ) and magnetic (~104 T) fields. Furthermore, these results contribute to the development of next generation compact accelerators suitable for many applications such as isochoric heating for ion-fast ignition and producing warm dense matter for basic science.

43 PARTICLE ACCELERATORS↗
DOE OSTI2014

Ion probe beam experiments and kinetic modeling in a dense plasma focus Z-pinch

The Z-pinch phase of a dense plasma focus (DPF) emits multiple-MeV ions in a ∼cm length. The mechanisms through which these physically simple devices generate such high energy beams in a relatively short distance are not fully understood. We are exploring the origins of these large gradients using measurements of an ion probe beam injected into a DPF during the pinch phase and the first kinetic simulations of a DPF Z-pinch. To probe the accelerating fields in our table top experiment, we inject a 4 MeV deuteron beam along the z-axis and then sample the beam energy distribution after it passes through the pinch region. Using this technique, we have directly measured for the first time the acceleration of an injected ion beam. Our particle-in-cell simulations have been benchmarked on both a kJ-scale DPF and a MJ-scale DPF. They have reproduced experimentally measured neutron yields as well as ion beams and EM oscillations which fluid simulations do not exhibit. Direct comparisons between the experiment and simulations enhance our understanding of these plasmas and provide predictive design capability for accelerator and neutron source applications.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2015

SU-E-T-36: A GPU-Accelerated Monte-Carlo Dose Calculation Platform and Its Application Toward Validating a ViewRay Beam Model

Purpose: To build a fast, accurate and easily-deployable research platform for Monte-Carlo dose calculations. We port the dose calculation engine PENELOPE to C++, and accelerate calculations using GPU acceleration. Simulations of a Co-60 beam model provided by ViewRay demonstrate the capabilities of the platform. Methods: We built software that incorporates a beam model interface, CT-phantom model, GPU-accelerated PENELOPE engine, and GUI front-end. We rewrote the PENELOPE kernel in C++ (from Fortran) and accelerated the code on a GPU. We seamlessly integrated a Co-60 beam model (obtained from ViewRay) into our platform. Simulations of various field sizes and SSDs using a homogeneous water phantom generated PDDs, dose profiles, and output factors that were compared to experiment data. Results: With GPU acceleration using a dated graphics card (Nvidia Tesla C2050), a highly accurate simulation – including 100*100*100 grid, 3×3×3 mm3 voxels, <1% uncertainty, and 4.2×4.2 cm2 field size – runs 24 times faster (20 minutes versus 8 hours) than when parallelizing on 8 threads across a new CPU (Intel i7-4770). Simulated PDDs, profiles and output ratios for the commercial system agree well with experiment data measured using radiographic film or ionization chamber. Based on our analysis, this beam model is precise enough for general applications. Conclusions: Using a beam model for a Co-60 system provided by ViewRay, we evaluate a dose calculation platform that we developed. Comparison to measurements demonstrates the promise of our software for use as a research platform for dose calculations, with applications including quality assurance and treatment plan verification.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

An Advanced Simulation Toolkit for Photon Band Gap Accelerators

Photon band gap (PBG) structures have been investigated for accelerator and microwave tube applications over the past decade, and these investigations have concentrated on two distinct concepts. In one approach, a traditional accelerator slow-wave structure is created with a sequence of cavities of a new type that each contains a specially designed lattice of rods that endow it with desirable properties. Another more recent application of the same concept is to use a photonic crystal to confine the synchronous mode at the boundary of a dielectric wall accelerator (DWA), but let other modes excited by the beam escape. A related concept is the photonic crystal accelerator.

43 PARTICLE ACCELERATORS↗
DOE OSTI2017

A Compact Superconducting RF Accelerator for Electron Beam and X-ray Irradiation

As commercial and industrial applications of electron beam and x-ray irradiation have developed, new applications have emerged that require very high beam power to create the required radiation field. These new applications require dependable, efficient, high-energy, high-power electron accelerators. Recent developments in Superconducting Radio-Frequency (SRF) technology can now enable accelerators with lower costs and improved performance. Cryogenic heat loads are dramatically reduced through use of new materials and improved component designs. New cooling methods allow the replacement of complex systems requiring cryogenic fluids with simple robust systems with no fluids. New RF sources can greatly reduce the cost of RF power. Each of these developments has been individually proven and an effort is underway at the Illinois Accelerator Research Center at Fermilab to integrate them into the first prototype of an entirely new class of industrial SRF-based accelerators. These accelerators will enable robust, turn-key operation with very high electrical efficiency. The accelerator prototype under design will be capable of 10 MeV beam, CW operation, and 250 kW of electron beam power. These modular systems are small enough to be palletized and transported to the point of use. Their high electrical efficiency mean that portable power generation systems can be enable their use in mobile applications. The goal is a compact, cost-effective, high-power accelerator suitable for many of the applications covered by this conference. Fermilab is actively working to build the prototype. The end-product will be a commercially available, robust, turn-key system for applications requiring reliable electron beam or X-ray irradiation. Keywords: accelerator, applications, conduction-cooling, cryogen-free, industrial, super-conducting RF.

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

High-Level Synthesis of Irregular Applications: A Case Study on Influence Maximization

The Influence Maximization problem is the problem of identifying a small cohort of actors from a broader population that, when initially activated in a diffusion process, are expected to result in a large number of activations in the population. While the problem is known to be NP-hard, several approximation algorithms have been devised by leveraging its submodular structure. While these algorithms are theoretically efficient, they are computationally very expensive in practice. This work advances the current state-of-the-art parallelization scheme for the IMM algorithm by devising the adoption of custom hardware accelerators implemented on FPGAs by leveraging High Level Synthesis from OpenCL. We study the performance of our proposed approach by exploring optimizations tailored at improving the parallel efficiency of the accelerators and highlight their effects and limitations in accelerating complex graph analytic applications. Our experimental evaluation shows that FPGA acceleration can improve the performance of the LT diffusion model up to 1.72x for the entire application and up to 2.90x for its most important kernel with respect to a CPU only parallel execution. The FPGA acceleration of the LT model shows also a 1.54x reduction in energy consumption when compared to a parallel CPU only run.

Neff, Reece W.↗
DOE OSTI2018

International Workshop on the Next Generation Gamma-ray Sources

New capabilities in Laser Compton Photon Sources (LCPS) are made possible by advances in the enabling laser, photon optics and electron accelerator technologies. LCPSs provide intense photon beams with narrow energy spread for use in a wide variety of research and applications. This workshop brought together scientists from international communities who use or develop LCPSs to report on recent achievements and to explore concepts for the next generation LCPS and the scientific research and applications that would be made possible by its realization. The topics covered at the workshop included: nuclear physics, applications, material science, advanced accelerator technologies, and life, earth and ocean sciences. Gamma-ray beams from LCPSs enable reach in several areas at the frontier of nuclear physics research, e.g., nuclear structure, nuclear astrophysics, internal structure of neutrons and protons, and features of quantum chromodynamics at low energies. The workshop allowed for a broad survey of applications of gamma-ray beams from LCPSs that include, homeland and nuclear security, medical technologies, and particle detection and imaging instrumentation. The workshop discussions and findings will be published in a whitepaper that will be accessible to the general public. The main objective of the workshop was to gather input from the participants, to stimulate new ideas that lead to identifying research opportunities and applications that should drive the performance specifications of the next major advancements in LCPSs, and to synthesize the discussions and findings into a whitepaper document. Inherent in these goals is brainstorming about advancements in accelerator technologies, lasers and optics for viable solutions to producing gamma-rays beams with characteristics that enable new opportunities in research and applications. World-renowned experts participated in the workshop and are leading the writing of the whitepaper. The workshop opened with plenary talks that provided reviews of key areas for the purpose of establishing the focus for each topical working group. The workshop concluded with a presentation by each working group that summarized the group’s findings and conclusions. The whitepaper will be released to the public before the next national long-range planning in nuclear physics.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
NASA NTRS2007

Fluence Uniformity Measurements in an Electron Accelerator Used for Irradiation of Extended Area Solar Cells and Electronic Circuits for Space Applications

It is common to have liquid crystal displays and electronic circuit boards with area sizes of the order of 20x20 sq cm on board of satellites and space vehicles. Usually irradiating them at different fluence values assesses the radiation damage in these types of devices. As a result, there is a need for a radiation source with large spatial fluence uniformity for the study of the damage by radiation from space in those devices. Kent State University s Program on Electron Beam Technology has access to an electron accelerator used for both research and industrial applications. The electron accelerator produces electrons with energies in the interval from 1 to 5 MeV and a maximum beam power of 150 kW. At such high power levels, the electron beam is continuously scanned back and forth in one dimension in order to provide uniform irradiation and to prevent damage to the sample. This allows for the uniform irradiation of samples with an area of up to 1.32 sq m. This accelerator has been used in the past for the study of radiation damage in solar cells (1). However in order to irradiate extended area solar cells there was a need to measure the uniformity of the irradiation zone in terms of fluence. In this paper the methodology to measure the fluence uniformity on a sample handling system (linear motion system), used for the irradiation of research samples, along the irradiation zone of the above-mentioned facility is described and the results presented. We also illustrate the use of the electron accelerator for the irradiation of large area solar cells (of the order of 156 sq cm) and include in this paper the electrical characterization of these types of solar cells irradiated with 5 MeV electrons to a total fluence of 2.6 x 10(exp 15) e/sq cm.

Uribe, Roberto M.↗
NASA NTRS1981

A transient MHD model applicable for the source of solar cosmic ray acceleration

A two-dimensional, time-dependent magnetohydrodynamic model is used to describe the possible mechanisms for the source of solar cosmic ray acceleration following a solar flare. The hypothesis is based on the propagation of fast mode MHD shocks following a sudden release of energy. In this presentation, the effects of initial magnetic topology and strength on the formation of MHD shocks have been studied. The plasma beta (thermal pressure/magnetic pressure) is considered as a measure of the initial, relative strength of the field. During dynamic mass motion, the Alfven Mach number is the more appropriate measure of the magnetic field's ability to control the outward motion. It is suggested that this model (computed self-consistently) provides the shock waves and the disturbed mass motion behind it as likely sources for solar cosmic ray acceleration.

Dryer, M.↗
NASA NTRS2005

Convergence Acceleration and Documentation of CFD Codes for Turbomachinery Applications

The development and analysis of turbomachinery components for industrial and aerospace applications has been greatly enhanced in recent years through the advent of computational fluid dynamics (CFD) codes and techniques. Although the use of this technology has greatly reduced the time required to perform analysis and design, there still remains much room for improvement in the process. In particular, there is a steep learning curve associated with most turbomachinery CFD codes, and the computation times need to be reduced in order to facilitate their integration into standard work processes. Two turbomachinery codes have recently been developed by Dr. Daniel Dorney (MSFC) and Dr. Douglas Sondak (Boston University). These codes are entitled Aardvark (for 2-D and quasi 3-D simulations) and Phantom (for 3-D simulations). The codes utilize the General Equation Set (GES), structured grid methodology, and overset O- and H-grids. The codes have been used with success by Drs. Dorney and Sondak, as well as others within the turbomachinery community, to analyze engine components and other geometries. One of the primary objectives of this study was to establish a set of parametric input values which will enhance convergence rates for steady state simulations, as well as reduce the runtime required for unsteady cases. The goal is to reduce the turnaround time for CFD simulations, thus permitting more design parametrics to be run within a given time period. In addition, other code enhancements to reduce runtimes were investigated and implemented. The other primary goal of the study was to develop enhanced users manuals for Aardvark and Phantom. These manuals are intended to answer most questions for new users, as well as provide valuable detailed information for the experienced user. The existence of detailed user s manuals will enable new users to become proficient with the codes, as well as reducing the dependency of new users on the code authors. In order to achieve the objectives listed, the following tasks were accomplished: 1) Parametric Study Of Preconditioning Parameters And Other Code Inputs; 2) Code Modifications To Reduce Runtimes; 3) Investigation Of Compiler Options To Reduce Code Runtime; and 4) Development/Enhancement of Users Manuals for Aardvark and Phantom

Marquart, Jed E.↗