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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 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
NASA NTRS2012

Performance and Environmental Test Results of the High Voltage Hall Accelerator Engineering Development Unit

NASA Science Mission Directorate's In-Space Propulsion Technology Program is sponsoring the development of a 3.5 kW-class engineering development unit Hall thruster for implementation in NASA science and exploration missions. NASA Glenn and Aerojet are developing a high fidelity high voltage Hall accelerator that can achieve specific impulse magnitudes greater than 2,700 seconds and xenon throughput capability in excess of 300 kilograms. Performance, plume mappings, thermal characterization, and vibration tests of the high voltage Hall accelerator engineering development unit have been performed. Performance test results indicated that at 3.9 kW the thruster achieved a total thrust efficiency and specific impulse of 58%, and 2,700 sec, respectively. Thermal characterization tests indicated that the thruster component temperatures were within the prescribed material maximum operating temperature limits during full power thruster operation. Finally, thruster vibration tests indicated that the thruster survived the 3-axes qualification full-level random vibration test series. Pre and post-vibration test performance mappings indicated almost identical thruster performance. Finally, an update on the development progress of a power processing unit and a xenon feed system is provided.

Kamhawi, Hani↗
DOE OSTI2025

AI-Driven Accelerated Inclusion Analysis for Energy Efficient Steelmaking (Final CRADA Report)

This was a collaborative effort between Lawrence Livermore National Security, LLC (LLNS) as manager and operator of Lawrence Livermore National Laboratory (LLNL) and ArcelorMittal USA Research LLC (“ArcelorMittal” as the Participant), to use scanning electron microscopy (SEM) images, computer vision and machine learning methods, and high-performance computing to accelerate the inclusion analysis process of liquid steel so that new methods can be used for near-real time process control on the shop floor.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Multipacting Processing in Cryomodules For LCLS-II And LCLS-II-HE

Multipacting (MP) is a phenomenon which can affect stability in particle accelerators and limit performance in superconducting radio frequency cavities. In the TESLA shaped, 1.3 GHz, 9-cell cavities used in the LCLS-II (L2) and LCLS-II-HE (HE) projects, the MP-band (~17-24 MV/m) lies within the required accelerating gradients. For HE, the operating gradient of 20.8 MV/m lies well within the MP-band and cryomodule testing has confirmed that this is an issue. As such, MP processing for the HE cryomodule test program will be discussed. Early results on MP processing in cryomodules installed in the L2 linac will also be presented, demonstrating that the methods used in cryomodule acceptance testing are also successful at conditioning MP in the accelerator and that this processing is preserved in the mid-term.

43 PARTICLE ACCELERATORS↗
DOE OSTI2025

Accelerating detector simulations with Celeritas: profiling and performance optimizations

Celeritas is a GPU-optimized MC particle transport code designed to meet the growing computational demands of next-generation HEP experiments. It provides efficient simulation of EM physics processes in complex geometries with magnetic fields, detector hit scoring, and seamless integration into Geant4-driven applications to offload EM physics to GPUs. Recent efforts have focused on performance optimizations and expanding profiling capabilities. This paper presents some key advancements, including the integration of the Perfetto system profiling tool for detailed performance analysis and the development of track-sorting methods to improve computational efficiency.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRS1993

Reach performance while wearing the Space Shuttle launch and entry suit during exposure to launch accelerations

Crewmen aboard the Space Shuttle are subjected to accelerations during ascent (the powered flight phase of launch) which range up to +3 G(sub x). Despite having 33 missions and nine years experience, not to mention all the time spent in development prior to the first flight, no truly quantitative reach study wearing actual crew equipment, using actual Shuttle seats and restraints has ever been done. What little information exists on reach performance while under acceleration has been derived primarily from subjective comments gathered retrospectively from Shuttle flight crews during their post mission debrief. This lack of reach performance data has resulted in uncertainty regarding emergency procedures that can realistically be performed during and actual Shuttle ascent versus what is practiced in the ground-fixed and motion-based Shuttle Simulators. With the introduction on STS-26 of the current Shuttle escape system, the question of reach performance under launch accelerations was once again raised. The escape system's requirement that each crewman wear a Launch/Entry Suit (LES), parachute harness, and parachute were all anticipated to contribute to a further degradation of reach performance during Shuttle ascent accelerations. In order to answer the reach performance question in a quantitative way, a photogrammetric method was chosen so that the actual reach values and associated envelopes could be captured. This would allow quantitative assessment of potential task performance impact and identify areas where changes to our Shuttle ascent emergency procedures might be required. Also, such a set of reach values would be valid for any similar acceleration profile using the same crew equipment. Potential Space Station applications of this data include predicting reach performance during Assured Crew Return Vehicle (ACRV) operations.

Bagian, James P.↗
DOE OSTI2026

Advancing Conduction-Cooled 650 MHz SRF Technology for Industrial Accelerators at Fermilab's IARC

The National Nuclear Security Administration (NNSA) funds the Illinois Accelerator Research Center (IARC) at Fermilab in developing a high-power, conduction-cooled Superconducting Radio Frequency (SRF) accelerator tailored for industrial applications requiring robust and efficient operation. A 650 MHz, 1.6 MeV, 20 kW SRF accelerator is currently under development, employing a conduction cooling approach to simplify cryogenic requirements and enhance accessibility for industrial use. The accelerator’s control system is implemented on the Blinky Lite platform, selected for its open-source architecture, secure remote access capabilities, and operational flexibility—attributes advantageous for industrial deployment and sustained operation. A dedicated beamline is designed to measure essential beam parameters and test the integrated performance of the accelerator and control systems, thereby validating their operational readiness for intended applications

Ji, Y. [Fermilab] (ORCID:0000000233981752)↗
DOE OSTI2025

Advancing Conduction-Cooled 650 MHZ SRF Technology for Industrial Accelerators at Fermilab S IARC

The National Nuclear Security Administration (NNSA) funds the Illinois Accelerator Research Center (IARC) at Fermilab in developing a high-power, conduction-cooled Superconducting Radio Frequency (SRF) accelerator tailored for industrial applications requiring robust and efficient operation. A 650 MHz, 1.6 MeV, 20 kW SRF accelerator is currently under development, employing a conduction cooling approach to simplify cryogenic requirements and enhance accessibility for industrial use. The accelerator's control system is implemented on the Blinky Lite platform, selected for its open-source architecture, secure remote access capabilities, and operational flexibility attributes advantageous for industrial deployment and sustained operation. A dedicated beamline is designed to measure essential beam parameters and test the integrated performance of the accelerator and control systems, thereby validating their operational readiness for intended applications.

Ji, Yichen [Fermilab]↗
NASA NTRS2008

Effects of Different Lifting Cadences on Ground Reaction Forces during the Squat Exercise

The purpose of this investigation was to determine the effect of different cadences on the ground reaction force (GRF(sub R)) during the squat exercise. It is known that squats performed with greater acceleration will produce greater inertial forces; however, it is not well understood how different squat cadences affect GRF(sub R). It was hypothesized that faster squat cadences will result in greater peak GRF(sub R). METHODS: Six male subjects (30.8+/-4.4 y, 179.5+/-8.9 cm, 88.8+/-13.3 kg) with previous squat experience performed three sets of three squats using three different cadences (FC = 1 sec descent/1 sec ascent; MC = 3 sec descent/1 sec ascent; SC = 4 sec descent/2 sec ascent) with barbell mass equal to body mass. Ground reaction force was used to calculate inertial force trajectories of the body plus barbell (FI(sub system)). Forces were normalized to body mass. RESULTS: Peak GRF(sub R) and peak FI(sub system) were significantly higher in FC squats compared to MC (p=0.0002) and SC (p=0.0002). Range of GRF(sub R) and FI(sub system) were also significantly higher in FC compared to MC (p<0.05), and MC were significantly higher than SC (p<0.05). DISCUSSION: Faster squat cadences result in significantly greater peak GRF(sub R) due to the inertia of the system. GRF(sub R) was more dependent upon decent cadence than on ascent cadence. PRACTICAL APPLICATION: This study demonstrates that faster squat cadences produce greater ground reaction forces. Therefore, the use of faster squat cadences might enhance strength and power adaptations to long-term resistance exercise training. Key Words: velocity, weight training, resistive exercise

Bentley, Jason R.↗
DOE OSTI2022

Nb$_3$Sn Superconducting Radiofrequency Cavities: a Maturing Technology for Particle Accelerators and Detectors

Nb3Sn superconducting radiofrequency (SRF) cavities have substantial potential for enabling new performance capabilities for particle accelerators for high energy physics (HEP), as well as for RF cavity-based detectors for dark matter, gravitational waves, and other quantum sensing applications. Outside of HEP, Nb3Sn SRF cavities can also benefit accelerators for nuclear physics, basic energy sciences, and the industry. In this contribution to Snowmass 2021, we overview the potential, status, and outlook of Nb3Sn SRF cavities.

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

Accelerated Deterministic Phonon Transport With Consistent Material Temperature and Intensities

Abstract We present a method for deterministically solving the frequency and temperature dependent phonon radiative transport (PRT) equation in the single-mode relaxation time (SMRT) approximation in the self-adjoint angular flux (SAAF) form. To handle the nonlinear coupling between the phonon intensities and the material temperature, we apply a linearization approach that is similar to one in thermal radiative transport. This procedure leads to the PRT equation with pseudo-scattering. The method presented includes acceleration of both the inner pseudo-scattering source iterations and outer temperature iteration with a gray diffusion synthetic acceleration (DSA) and Anderson acceleration, respectively. We use the finite-element method to discretize the PRT equation in space and the method of discrete ordinates (SN) for angular discretization. The proposed method is verified by a gray method of manufactured solutions problem and demonstrated on a problem using temperature and direction dependent multigroup data from lithium aluminate (LiAlO2). The iterative performance of the acceleration method in each test is then compared to the unaccelerated method.

Engineering↗
DOE OSTI2022

Future Circular Lepton Collider FCC-ee: Overview and Status

The worldwide High Energy Physics community widely agrees that the next collider should be a Higgs factory. Acknowledging this priority, in 2021 CERN has launched the international Future Circular Collider (FCC) Feasibility Study (FS). The FCC Integrated Project foresees, in a first stage, a high-luminosity high-energy electron-positron collider, serving as Higgs, top and electroweak factory, and, in a second stage, an energy frontier hadron collider, with a centre-of-mass energy of at least 100 TeV. In this paper, we address a few key elements of the FCC-ee accelerator design, its performance reach, and underlying technologies, as requested by the Snowmass process. The Conceptual Design Report for the FCC, published in 2019, serves as our primary reference. We also summarize a few recent changes and improvements.

43 PARTICLE ACCELERATORS↗
NASA NTRS1983

Convergence and stability properties of minimal polynomial and reduced rank extrapolation algorithms

The minimal polynomial and reduced rank extrapolation algorithms are two acceleration of convergence methods for sequences of vectors. In a recent survey these methods were tested and compared with the scalar, vector, topological epsilon algorithms, and were observed to be more efficient than the latter. It was also observed that the two methods have similar convergence properties. The convergence and stability properties of these methods are analyzed and the performance of the acceleration methods when applied to a class of vector sequences that includes those sequences obtained from systems of linear equations by using matrix iterative methods is discussed.

Sidi, A.↗
DOE OSTI2020

Demonstration of transmission high energy electron microscopy

Charged particle radiography with 800 MeV protons has been used for decades at LANL and developed around the world to study dynamic material properties. Recently, charged particle radiography has been demonstrated with the use of high-energy electrons. Because of the difference in the mass of the electron compared to the mass of the proton, the radiographic processes are substantially different and well suited to the study of fast dynamic processes in relatively thin systems. This presentation will show the layout required for such measurements, along with data collected from this recent demonstration performed with 14 GeV electrons generated at the SLAC National Accelerator Laboratory. The radiographic performance for flash measurements will be presented, along with the limitations of this measurement technique.

Merrill, F. E.↗
DOE OSTI2021

Pharmacokinetics, Metabolite Measurement, and Biomarker Identification of Dermal Exposure to Permethrin Using Accelerator Mass Spectrometry

Impregnating military uniforms and outdoor clothing with the insecticide permethrin is an approach to reduce exposure to insect borne diseases and to repel pests and disease vectors such as mosquitos and sandflies, but the practice exposes wearers to prolonged dermal exposure to the pesticide. Key metabolite(s) from a low dose dermal exposure of permethrin were identified using accelerator mass spectrometry. Metabolite standards were synthesized and a high performance liquide chromatography (HPLC) elution protocol to separate individual metabolites in urine was developed. Six human subjects were exposed dermally on the forearm to 25 mg of permethrin containing 1.0 µCi of 14 C for 8 h. Blood, saliva and urine samples were taken for 7d. Absorption/elimination rates and metabolite concentrations varied by individual. Average absorption was 0.2% of the dose. Serum concentrations rose until 12–24 h postdermal application then rapidly declined reaching predose levels by 72 h. Maximum saliva excretion occurred 6 h postdosing. The maximum urinary excretion rate occurred during 12–24 h; average elimination half-life was 56 h. 3-Phenoxybenzyl alcohol glucuronide was the most abundant metabolite identified when analyzing elution fractions, but most of the radioactivity was in still more polar fractions suggesting extensive degradative metabolism and for which there were no standards. Finally, analyses of archived urine samples with the ultra performance liquid chromatography-accelerator mass spectrometry-mass spectrometry (UPLC-AMS-MS) system isolated a distinct polar metabolite but it was much diminished from the previous analyses a decade earlier.

59 BASIC BIOLOGICAL SCIENCES↗