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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.

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At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Distributed Fiber Optic Sensing to Identify Locations of Resistive Transitions in REBCO Conductors and Magnets

High-temperature superconductors such as REBa 2 Cu 3 O 7-x (REBCO, RE = rare earth) can generate strong magnetic fields that are promising for applications in particle accelerators and compact fusion reactors. Traditionally, voltage taps are installed in superconducting magnets to measure the voltage signals due to resistive transitions. The voltage-tap-based diagnostics is important for the development of magnet technology as it can help pinpoint the locations in the magnet windings that limit the magnet performance. The architecture of the multi-tape REBCO cable such as CORC wires, however, makes it difficult to apply the voltage-tap-based diagnostics to identify the locations of resistive transitions. Distributed fiber optic sensing (DFOS) has the potential to address this issue. In this paper, we report the measurements of thermal strain along a CORC wire based on optical frequency domain reflectometry with a maximum spatial resolution of 0.65 mm and a temporal resolution of 10 Hz. The optical fiber is co-wound with the CORC wire that is epoxy impregnated. During the test, current was increased until a resistive transition occurred in the conductor. The spectrum shift of the reflected light along the fiber was recorded. The results suggested that with proper thermal isolation from the cryogen, DFOS can be used to identify the locations of resistive transitions in CORC wires and magnets. In conclusion, the results will allow a better understanding of the causes of resistive transitions in REBCO conductors and magnets, which will help improve the REBCO magnet technology.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2021

Optical Spectrometer With a Pulse-to-Pulse Resolution for Terahertz and mm-Wave Signals

The development of ultra-compact particle accelerators and accelerator-based high-power THz generators are some of the top priorities for research and development programs around the world. These tools require the development of accelerating structures, operating in the mm-Wave and THz range, where diagnostics are not available or are insufficient. This article presents the design of a pulse-to-pulse THz spectrometer, primarily developed for diagnostics of accelerating structures and THz radiation sources. In particular, this spectrometer can be used to detect RF pulse shortening caused by vacuum breakdown and beam misalignment in THz accelerators, as well as for bunch length monitoring and radiation source diagnostics. The spectrometer is based on a diffraction grating and is capable of covering a frequency range where RF-based breakdown measurements are not possible. We have built and tested the first prototype with different sources in a frequency range of 0.1-1.0 THz. In this article, we present the physical design, supported numerical simulations, electronics development, and test results.

47 OTHER INSTRUMENTATION↗
DOE OSTI2022

USING E-BEAM IRRADIATION BEAMLINE AT JEFFERSON LAB TO REMOVE 1,4-DIOXANE AND PFAS IN WASTEWATER

The designed e-beam irradiation beamline [1] at Jefferson Lab has been commissioned and applied to study the degradation removal of 1,4-dioxane and per- and polyfluoroalkyl substances (PFAS) in wastewater by collaborating with Hampton Roads Sanitation District (HRSD), treating wastewater in southeast Virginia. The absorbed dose and dose distribution in the entire sample were achieved innovatively using Monte-Carlo simulations that were calibrated with opti-chromic dosimeter rods directly exposed to the e-beam. This research could be a stepstone to the future MW compact SRF accelerator [2] for wastewater remediation.

Li, X.↗
DOE OSTI2025

Exploring Catalyst Compositions for Microwave-Assisted Methane Dehydroaromatization

The flaring of natural gas in U.S. shale regions remains a challenge for producers. One alternative to flaring is converting the wasted gas into valuable chemicals. Microwave-based processes offer a promising solution, potentially enabling the development of compact, modular systems for on-site production of chemicals, such as aromatics, from natural gas. This is due to the advantages of microwave heating, including efficient heating of compact volumes, accelerated reaction rates, and electrification of heating. However, developing effective catalysts for microwave-based processes is challenging, as conventional materials often require modification to be effectively heated by microwaves. This study provides an overview of a catalyst development project focused on a molybdenum-supported zeolite catalyst, optimized for the direct conversion of methane into aromatics under microwave irradiation. It details the synthesis, characterization, and the effects of promoters, as well as computational efforts undertaken to understand and enhance the catalyst's performance.

flare gas↗
DOE OSTI2019

Active Experiments in Space: The Future

Planned active space experiments and ideas for future active space experiments are reviewed. Three active experiments being readied are DSX (Demonstration and Space eXperiments), SMART (Space Measurement of Rocket-released Turbulence), and BeamPIE (Beam Plasma Interaction Experiment). Ideas for future experiments include relativistic-electron-beam experiments for magnetic-field-line tracing, relativistic-electron-beam experiments to probe the middle atmosphere, plasma-wave launching using superparamagnetic-nanoparticle amplification of magnetic fields, the heavy-ion mass loading of collisionless magnetic-field-line reconnection, the use of electrostatically charged tethers to pitch-angle scatter radiation-belt particles, cold plasma releases to modify magnetospheric plasma physics, and neutral-gas releases to enhance neutral-particle imaging of the magnetosphere. Technologies that are being developed to enable future space active experiments are reviewed: this includes the development of compact relativistic accelerators, superparamagnetic particle amplified antennae, CubeSats, and a new understanding of how to control dynamic spacecraft charging. New capabilities to use laboratory facilities to design space active experiments as well as new computer-simulation capabilities to design and understand space active experiments are reviewed.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1988

X-ray and radio properties of solar (He-3) rich events

Radio and X-ray properties of solar flares associated with a new sample of individual (He-3) rich solar particle events are examined. Given the association between kilometric type III bursts and (He-3) rich events, the timing of the radio events is used to identify the related X-ray increases. The X-ray events exhibit a rich variety, from the standpoint of both intensity and complexity. Examination of the events shows statistically significant anticorrelations between the He-3/He-4 ratio and the intensity of the event as measured at kilometric wavelengths and in hard and soft X-rays; larger He-3/He-4 ratios occur in smaller flares. The result suggests that a coupling may exist between the preheating phase and the acceleration phase of these events or that mixing occurs between an enriched particle population accelerated within the compact flare and a normal population accelerated by a shock propagating away from an intense flare.

Reames, D. V.↗
NASA NTRS1991

LLNL contributions to MPD thrusters for SEI

Some of the topics covered with respect to the Lawrence Livermore National Laboratory's (LLNL's) contributions to Magnetoplasmadynamic (MPD) Thrusters for the Space Exploration Initiative (SEI) include: an IR camera, plasma-induced erosion/redeposition, the Mirror Fusion Test Facility-B (MFTF-B), the Thruster Lifetime Test Facility, the RACE Compact Torus Accelerator Facility, and a RACE program summary. Some of the other topics addressed include: flux contours for HAM simulation, comparison of RACE data of plasma ring formation with the HAM 2-D magnetohydrodynamic code, and the 2-D Ring Acceleration Code (TRAC).

Hooper, Edwin Bickford↗
NASA NTRS2004

NASA Tech Briefs, February 2004

Topics include: Simulation Testing of Embedded Flight Software; Improved Indentation Test for Measuring Nonlinear Elasticity; Ultraviolet-Absorption Spectroscopic Biofilm Monitor; Electronic Tongue for Quantitation of Contaminants in Water; Radar for Measuring Soil Moisture Under Vegetation; Modular Wireless Data-Acquisition and Control System; Microwave System for Detecting Ice on Aircraft; Routing Algorithm Exploits Spatial Relations; Two-Finger EKG Method of Detecting Evasive Responses; Updated System-Availability and Resource-Allocation Program; Routines for Computing Pressure Drops in Venturis; Software for Fault-Tolerant Matrix Multiplication; Reproducible Growth of High-Quality Cubic-SiC Layers; Nonlinear Thermoelastic Model for SMAs and SMA Hybrid Composites; Liquid-Crystal Thermosets, a New Generation of High-Performance Liquid-Crystal Polymers; Formulations for Stronger Solid Oxide Fuel-Cell Electrolytes; Simulation of Hazards and Poses for a Rocker-Bogie Rover; Autonomous Formation Flight; Expandable Purge Chambers Would Protect Cryogenic Fittings; Wavy-Planform Helicopter Blades Make Less Noise; Miniature Robotic Spacecraft for Inspecting Other Spacecraft; Miniature Ring-Shaped Peristaltic Pump; Compact Plasma Accelerator; Improved Electrohydraulic Linear Actuators; A Software Architecture for Semiautonomous Robot Control; Fabrication of Channels for Nanobiotechnological Devices; Improved Thin, Flexible Heat Pipes; Miniature Radioisotope Thermoelectric Power Cubes; Permanent Sequestration of Emitted Gases in the Form of Clathrate Hydrates; Electrochemical, H2O2-Boosted Catalytic Oxidation System; Electrokinetic In Situ Treatment of Metal-Contaminated Soil; Pumping Liquid Oxygen by Use of Pulsed Magnetic Fields; Magnetocaloric Pumping of Liquid Oxygen; Tailoring Ion-Thruster Grid Apertures for Greater Efficiency; and Lidar for Guidance of a Spacecraft or Exploratory Robot.

Source record↗
DOE OSTI2024

PROGRESS ON MAGNETRON R&DS FOR INDUSTRIAL PARTICLE ACCELERATORS

The magnetron as an efficient RF source for a compact industrial SRF accelerator has been developed. The per-formance of injection phase lock on two independent magnetron transmitters operated at 915MHz, in CW mode with maximum power of 75kW each has been demon-strated to satisfy this application. This industrial type magnetron has AC transformer and the SCR rectifier on the DC anode power supply. Output power spectrum with phase locking can achieve noise reduction of -21.2 dBc at the 1st 60 Hz, -28.0 dBc at 1st 180 Hz with only -22.6 dBc injection power. Further control studies for 2×75 kW, 915 MHz power combing by WR975 magic-tee at Jefferson Lab (JLab) and for 4×1.2 kW, 2.45 GHz power combing by WR340 magic-tee at General Atomics (GA).

Rimmer, R.↗
NASA NTRS2010

Rocket Cratering in Simulated Lunar and Martian Environments

With NASA's planned return to the moon and possibly with lunar outposts being formed, repeated landings at the same site will be necessary. Understanding rocket plume interaction with lunar and Martian surfaces is of paramount importance in order to safely land and protect hardware surrounding the landing site. This work will report on results of three small experiments intended to explore plume impingement onto lunar and Martian surfaces: Handheld Observation of Scour Holes (HOOSH), Handheld Angle of Repose Measurements of Lunar Simulants (HARMLuS), and Mars Architecture Team study (MATS). The first two experiments were performed during two sorties of reduced gravity flights. HOOSH was designed to investigate crater formation as a function of gravitational level (lunar and Martian gravity). HARMLuS was designed to measure the Angle of Failure (related to the angle of repose) at lunar and Martian gravity. Both experiments have complex findings indicative of the hysteretic behavior of granular materials, especially resulting from reduced gravity. The MATS experiment was designed to investigate the effects of regolith compaction on the granular mechanics of crater formation . In general, the granular mechanics is a much stronger function of compaction than gravitation acceleration. Crater formation is greatly enhanced at reduced gravity (resulting in much larger craters). The angle of failure of the lunar simulants increases with decreasing gravitational acceleration, and occasionally becomes infinite for some compactions at lunar gravity. The angle of failure also increases with increasing compaction. While compaction does play a role in the time development of crater formation, the asymptotic behavior is largely unaffected.

Immer, Christopher↗
DOE OSTI2025

A high repetition rate millimeter wavelength accelerator for an X-ray free-electron laser

A compact collinear wakefield accelerator has been designed for an X-ray free-electron laser capable of operating at a pulse repetition rate in the tens of kilohertz. The maximum achievable accelerating gradient has been determined, with its limitation linked to beam breakup instability. The fabrication techniques for the principal components of the accelerator including wakefield generation, couplers for excess power extraction and diagnostics, focusing quadrupoles, and a novel undulator have been discussed. Results from various laboratory and beam-based tests on these components have been compared to their original design specifications and demonstrated very good agreement. A preliminary design for the XFEL has been presented, featuring a novel small-period, force-neutral, adjustable-phase undulator.

26 undulator↗
DOE OSTI2024

Light and Electron Emission as Breakdown Probes: Synergistic DC and RF Study

The project was motivated by a particular and critical need in accelerator R&D to understand vacuum breakdown and arc as it would allow for developing high gradient machines. Accelerator systems operated at high gradients are less costly and more compact. This, in turn, would enable advanced and cost-effective accelerators for future colliders. Universities and medical centers would be able to build compact accelerator machines for basic X-ray and microscopy sciences, therapy, isotope production, sterilization etc.

43 PARTICLE ACCELERATORS↗
DOE OSTI2025

Greater than 1000-fold Gain in a Free-Electron Laser Driven by a Laser-Plasma Accelerator with High Reliability

Compact free-electron lasers (FELs) based on plasma-based accelerators have been envisioned for many years. While recent milestone experiments have demonstrated feasibility, further progress is needed to establish laser-plasma-accelerator-driven FELs as reliable light sources. Demonstrating both full FEL saturation and reliable operation commensurate with conventional FEL facilities is critical. We report progress on both of these fronts. FEL gain exceeding 1000 at a wavelength of 420 nm in the self-amplified spontaneous emission regime has been measured. Lower and upper bounds for the characteristic exponential gain length were measured at 16.7-22.5 cm. Additionally, reliability of the laser-plasma-accelerator-driven FEL, defined here as the percentage of shots displaying FEL gain, reached an unprecedented level of greater than 90% over the course of an hour while operating at 1 Hz repetition rate.

Barber, S K↗
DOE OSTI2025

Compact cryomodule for mobile stand-alone superconducting industrial accelerators

Superconducting RF (SRF) accelerators have the potential to be more profitable in comparison with normally conducting accelerators, as long they can be made compact, achieve operational simplicity, autonomy, trans- portability, satisfactory energy efficiency, as well as have reasonable costs. The development of SRF technologies such as Nb 3 Sn coating, conductively-cooled resonators, and high-capacity liquid-helium-free cryocoolers made SRF accelerators mobile and energetically and economically efficient at a beam power of tens of kW. One of the key elements of such an accelerator is the cryomodule, which must have minimal thermal losses to enable operation from low power cryoheads and enable conductive cooling of SRF resonator. In this research we present the design and test results of a compact cryomodule for an industrial stand-alone SRF linear accelerator proto- type, based on 650 MHz elliptical resonators, being developed at Fermi National Accelerator Laboratory.

43 PARTICLE ACCELERATORS↗
DOE OSTI2025

Compact X-band split electron linac for cabinet-size small-sample irradiators

Many small-scale industrial radiation facilities rely on hazardous radioisotope-based gamma ray irradiators, which are being gradually replaced by alternative technologies, such as particle accelerators. RadiaBeam has developed a compact, cabinet-size, 3 MeV electron-linac-based irradiator to match the penetration of Co-60 and provide high irradiation throughput. Here the linac utilizes X-band RF power to reduce size, employs an innovative split-linac approach to lower costs, and features a novel X-ray conversion target geometry that spreads the beam out across the target, providing a low dose uniformity ratio. In this paper, we discuss the accelerator design, fabrication, and test results.

43 PARTICLE ACCELERATORS↗
DOE OSTI2020

Compact, Achromatic Non-scaling FFAG Accelerator for HEP, Commercial and Medical Applications (CRADA FRA-2008-0005 Final Report)

Proton and light-ion accelerators have many research and medical applications, but the current state of technology in accelerators severely limits their widespread use: (1) synchrotrons have an intrinsic low duty cycle and become quite large for light ions; and (2) cyclotrons do not have energy variability and require complex superconducting magnets for high energy. A new concept in non-scaling Fixed-Field Alternating-Gradient (FFAGs) has been invented that incorporates both the energy variability of the synchrotron and the high duty cycle of the cyclotron. The concept uses normal-conducting, combined-function magnets that apply only constant (dipole) and linear-gradient (quadrupole) fields to stabilize the accelerator. This project will develop an optimized design for a new non-scaling and cost-effective innovation in FFAG accelerators. The accelerator design will have optics that can stably accelerate protons to 250 MeV (or higher) and carbon ions to =200 MeV, an energy considered ideal for radiation therapy. Phase I will optimize, fully simulate, and demonstrate the feasibility of this accelerator. Commercial Applications and other Benefits as described by the awardee: The fixed-field acceleration concept should eliminate some of the most pronounced technical difficulties, expense, maintenance, and required expertise faced in conventional proton and light-ion accelerators. In addition to the application for high energy physics, these accelerators should have application in cancer treatment, radiopharmaceuticals, and medical isotope production, and materials science.

43 PARTICLE ACCELERATORS↗