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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS1990

NOAA/TIROS and GOES Observations of Galactic and Solar Cosmic Rays over a Solar Cycle

Correlations between solar activity and atmospheric processes have been investigated for more than 30 years, and the reality of the strong correlations found has been well accepted. However, it remains problematic to establish mechanisms capable of coupling the physical manifestations of solar variability to the lower atmosphere. There has been to date a lack of long-term satellite measurements of particles of sufficient energy to penetrate the Earth's atmosphere. The NOAA Space Environment Laboratory has maintained energetic particle detectors on board the NOAA/TIROS and GOES series of satellites. These instruments monitor the flux of energetic protons to energies greater than about 800 MeV. Measurements of particles above 350 MeV began October 1978, and continue to date. The instruments are briefly described, along with the current program to reduce the data. The goal is to provide a data base that will help to assess the significance of variations of atmospheric and ionospheric properties due to energetic particle precipitation.

Sauer, Herbert H.↗
NASA NTRS1990

Particle astronomy and particle physics from the moon - The particle observatory

Promising experiments from the moon using particle detectors are discussed, noting the advantage of the large flux collecting power Pc offered by the remote, stable environment of a lunar base. An observatory class of particle experiments is presented, based upon proposals at NASA's recent Stanford workshop. They vary from neutrino astronomy, particle astrophysics, and cosmic ray experiments to space physics and fundamental physics experiments such as proton decay and 'table-top' arrays. This research is background-limited on earth, and it is awkward and unrealistic in earth orbit, but is particularly suited for the moon where Pc can be quite large and the instrumentation is not subject to atmospheric erosion as it is (for large t) in low earth orbit.

Wilson, Thomas L.↗
NASA NTRS2000

Energetic Ion Interactions with the Galilean Satellites

The principal research tasks of this investigation are: (1) specification of the energetic (keV to MeV) ion environments upstream of the four Galilean satellites and (2) data analysis and numerical modeling of observed ion interactions with the satellites. Differential flux spectra are being compiled for the most abundant ions (protons, oxygen, and sulfur) from measurements at 20 keV to 100 MeV total energy by the Energetic Particle Detector (EPD) experiment and at higher ion energies by the Heavy Ion Counter (HIC) experiment. Runge-Kutta and other numerical techniques are used to propagate test particles sampled from the measured upstream spectra to the satellite surface or spacecraft through the local magnetic and corotational electric field environment of each satellite. Modeling of spatial variations in directional flux anisotropies measured during each close flyby provides limits on atomic charge states for heavy (O, S) magnetospheric ions and on internal or induced magnetic fields of the satellites. Validation of models for magnetic and electric field configurations then allows computation of rates for ion implantation, sputtering, and energy deposition into the satellite surfaces for further modeling of observable chemical changes induced by irradiation. Our ongoing work on production of oxidants and other secondary species by ice irradiation on Europa's surface has significant applications, already acknowledged in current literature, to astrobiological evolution. Finally, the work will improve understanding of energetic ion sources and sinks at the satellite orbits for improved modeling of magnetospheric transport processes. The scope of the research effort mainly includes data from the primary Galileo mission (1995-1997) but may also include some later data where directly relevant (e.g., comparison of J0 and I27 data for Io) to the primary mission objectives. Funding for this contract also includes partial support for our related education and public outreach activity, 'Interaction of Magnetospheric Particles Applied to Classroom Teaching (IMPACT).'

Cooper, John F.↗
NASA NTRS1972

Latitude and local time dependence of precipitated low energy electrons at high latitudes

Data from particle detectors on board the satellite OGO-4 were used to study the precipitation of electrons in the energy range 0.7 to 24 keV. The latitude dependence of these particles in the local time region from midnight to dawn was investigated in detail. The analysis shows that the precipitation of particles of energies 2.3 to 24 keV is centered at an invariant latitude of about 68 deg at midnight with a clear shift in latitude with increasing local time and this shift is more pronounced for lower energies. The highest fluxes of particles in this energy interval are measured at midnight and they decrease rapidly with local time. The data in the energy range 2.3 to 24 keV support a theory where particles are injected in the midnight region from the tail gaining energy due to a betatron process and then drift eastwards in a combined electric and magnetic field. The main part of the electrons at 0.7 keV show a different behavior. They seem to undergo an acceleration process which is rather local, sometimes giving field aligned fluxes which may be super-imposed on the background precipitation.

Gustafsson, G.↗
NASA NTRS1974

Particle impact location detector

Detector includes delay lines connected to each detector surface strip. When several particles strike different strips simultaneously, pulses generated by each strip are time delayed by certain intervals. Delay time for each strip is known. By observing time delay in pulse, it is possible to locate strip that is struck by particle.

Auer, S. O.↗
DOE OSTI2021

Response of CR-39 nuclear track detectors to protons with non-normal incidence

This paper presents data from experiments with protons at non-normal incidence to CR-39 nuclear track detectors, analyzing the properties of detection efficiency, proton track diameter, track contrast, and track eccentricity. Understanding the CR-39 response to protons incident at an angle is important for designing charged particle detectors for inertial confinement fusion (ICF) applications. This study considers protons with incident energies less than 3 MeV. In this regime, an incident angle of 10° has no effect on CR-39 detection efficiency, and >85% detection efficiency is preserved up through 25° in the range of 1.0 MeV–2.1 MeV. For ICF applications, incident angles above 30° are deemed impractical for detector design due to significant drops in proton detection at all energies. We observe significant reductions in detection efficiency compared to theoretical predictions, particularly at low energies where proton tracks are etched away. The proton track diameter measured by the scan system is observed to decrease with higher incident angles. The track diameters are analyzed with two fitting models, and it is shown that the diameter–energy relation can be fit with the existing models at angles up to 30° . The optical contrast of the tracks tends to increase with the angle, meaning that the tracks are fainter, and a larger increase is observed for higher energies. Eccentricity, a measure of how elongated proton tracks are, increases with the incident angle and drops after the critical angle. The lowest energy tracks remain nearly circular even at higher angles.

47 OTHER INSTRUMENTATION↗
DOE OSTI2021

Response of CR-39 nuclear track detectors to protons with non-normal incidence

This paper presents data from experiments with protons at non-normal incidence to CR-39 nuclear track detectors, analyzing the properties of detection efficiency, proton track diameter, track contrast, and track eccentricity. Understanding the CR-39 response to protons incident at an angle is important for designing charged particle detectors for inertial confinement fusion (ICF) applications. This study considers protons with incident energies less than 3 MeV. In this regime, an incident angle of 10° has no effect on CR-39 detection efficiency, and >85% detection efficiency is preserved up through 25° in the range of 1.0 MeV–2.1 MeV. For ICF applications, incident angles above 30° are deemed impractical for detector design due to significant drops in proton detection at all energies. We observe significant reductions in detection efficiency compared to theoretical predictions, particularly at low energies where proton tracks are etched away. The proton track diameter measured by the scan system is observed to decrease with higher incident angles. The track diameters are analyzed with two fitting models, and it is shown that the diameter–energy relation can be fit with the existing models at angles up to 30°. The optical contrast of the tracks tends to increase with the angle, meaning that the tracks are fainter, and a larger increase is observed for higher energies. Eccentricity, a measure of how elongated proton tracks are, increases with the incident angle and drops after the critical angle. The lowest energy tracks remain nearly circular even at higher angles.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRS1991

Energetic particles at Venus - Galileo results

At Venus the Energetic Particles Detector (EPD) on the Galileo spacecraft measured the differential energy spectra and angular distributions of ions above about 22 keV and electrons above about 15 keV in energy. The only time particles were observed by EPD was in a series of episodic events near closest approach (0559:03 UT). Angular distributions were highly anisotropic, ordered by the magnetic field, and showed ions arriving from the hemisphere containing Venus and its bow shock. The spectra showed a power law form with intensities observed into the 120- to 280-keV range. Comparisons with model bow shock calculations show that these energetic ions are associated with the Venusian foreshock-bow shock region. Shock-drift acceleration in the Venusian bow shock seems the most likely process responsible for the observed ions.

Williams, D. J.↗
NASA NTRS1976

An Atmospheric Cloud Physics Laboratory for the Space Laboratory

Results of research and engineering analyses to date show that it is feasible to develop and fly on the first Spacelab mission a multipurpose laboratory in which experiments can be performed on the microphysical processes in atmospheric clouds. The paper presents a series of tables on the Atmospheric Cloud Physics Laboratory, with attention given to experiment classes, the preliminary equipment list (particle generators, optical and imaging devices, particle detectors and characterizers, etc.), initial equipment (scientific equipment subsystems and flight support subsystems), and scientific functional requirements (the expansion chamber, the continuous flow diffusion chamber, the static diffusion chamber, the humidifier, and particle generators).

Smith, R.↗
NASA NTRS2000

Observed On-Orbit Background of the ACIS Detector on the Chandra X-Ray Observatory

We have analyzed calibration data acquired during the Orbital Activation and Checkout (OAC) phase of the Chandra X-ray Observatory (CXO) mission in order to characterize the background of the Advanced CCD Imaging Spectrometer (ACIS) produced by charged particles and non-cosmic X-rays. The ACIS instrument contains 8 Front-Illuminated (FI) CCDs and 2 Back-Illuminated (BI) CCDs. The FI and BI CCD)s exhibit dramatically different responses to enhancements in the particle flux. The F1 CCDs show relatively little increase in the overall count rate, typical increases are 1 - 3 counts/s; the BI CCDs show large excursions to as high as 100 counts/s. The duration of these intervals of enhanced background are highly variable ranging from 100 s to 5000 s. The spatial distribution of these background events is relatively flat across the power-law. The events produce morphologies which are similar to cosmic X-ray events, so that morphology alone cannot be used as a rejection criterion. We explore the correlation of these times of high background with the data from Chandra's on-board radiation monitor, the EPHIN (Electron, Proton, Helium Instrument particle detector) instrument and archival data from the Advanced Composition Explorer (ACE) satellite. We discuss strategies for observers to identify and exclude times of high background and to model and subtract the background events from their data.

Plucinsky, P. P.↗
NASA NTRS2015

Dose Calibration of the ISS-RAD Fast Neutron Detector

The ISS-RAD instrument has been fabricated by Southwest Research Institute and delivered to NASA for flight to the ISS in late 2015 or early 2016. ISS-RAD is essentially two instruments that share a common interface to ISS. The two instruments are the Charged Particle Detector (CPD), which is very similar to the MSL-RAD detector on Mars, and the Fast Neutron Detector (FND), which is a boron-loaded plastic scintillator with readout optimized for the 0.5 to 10 MeV energy range. As the FND is completely new, it has been necessary to develop methodology to allow it to be used to measure the neutron dose and dose equivalent. This talk will focus on the methods developed and their implementation using calibration data obtained in quasi-monoenergetic (QMN) neutron fields at the PTB facility in Braunschweig, Germany. The QMN data allow us to determine an approximate response function, from which we estimate dose and dose equivalent contributions per detected neutron as a function of the pulse height. We refer to these as the "pSv per count" curves for dose equivalent and the "pGy per count" curves for dose. The FND is required to provide a dose equivalent measurement with an accuracy of 10% of the known value in a calibrated AmBe field. Four variants of the analysis method were developed, corresponding to two different approximations of the pSv per count curve, and two different implementations, one for real-time analysis onboard ISS and one for ground analysis. We will show that the preferred method, when applied in either real-time or ground analysis, yields good accuracy for the AmBe field. We find that the real-time algorithm is more susceptible to chance-coincidence background than is the algorithm used in ground analysis, so that the best estimates will come from the latter.

Zeitlin, C.↗
DOE OSTI2021

Scaling Inference Using Triton to Accelerate Particle Physics at the LHC and DUNE

DUNE and the LHC experiments consist of unique and cutting-edge particle detectors that create massive, complex, and rich datasets with billions of events. They require sophisticated algorithms to reconstruct and interpret the data. Modern machine learning algorithms provide a powerful toolset to detect and classify particles, from familiar image processing convolutional neural networks to newer graph neural network architectures. A full reconstruction of these particle collisions requires novel approaches to handle the computing challenge of processing so much raw data. In a series of studies, physicists from Fermilab, CERN, and university groups explored how to accelerate their data processing using the Triton Inference Server.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2020

Water-based Liquid Scintillator detector as a new technology testbed for neutrino studies in Turkey

This study investigates the deployment of a medium-scale neutrino detector near Turkey's rst nuclear power plant, the Akkuyu Nuclear Power Plant. The aim of this detector is to become a modular testbed for new technologies in the elds of new detection media and innovative photosensors. Such technologies include Water-based Liquid Scintillator (WbLS), Large Area Picosecond Photo- Detectors (LAPPDs), dichroic Winston cones, and large area silicon photomul- tiplier modules. Here, the detector could be used for instantaneous monitoring of the Akkuyu Nuclear Power Plant via its antineutrino ux. In addition to its physics and technological goals, it would be an invaluable opportunity for the nuclear and particle physics community in Turkey to play a role in the development of next generation of particle detectors in the eld of neutrino physics.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRS1980

Disappearance and reappearance of particles of energies 50 keV as seen by P78-2 (SCATHA) near geosynchronous orbit

The nightside particle environment as observed by the AFGL Rapid Scan Particle Detector on SCATHA showing large, sudden simultaneous changes in the fluxes of electrons and protons with energies above 50 keV (dropouts) is considered. An interesting feature of SCATHA dropouts is the quasiperiodic behavior of the particle flux amplitudes which often vary with a period of the order of 15 minutes both during the dropout and after the return. A flux return during eclipse caused a major spacecraft charging event of several kilovolts. The SCATHA observations are compared with those reported for other geosynchronous satellites. In agreement with ATS-5, a marked dependence in the frequency of occurrence due to an effect of the orbit is found. ATS-5 experienced few dropouts during quiet geomagnetic conditions. However, for an L shell greater than seven, SCATHA particle dropouts occur routinely during quiet conditions. Thus, for SCATHA's orbit, both the orbital position and geomagnetic conditions must be taken into account in evaluating the potential hazard of flux returns.

Feynman, J.↗
NASA NTRS1982

Observations of large electric fields near the plasmasheet boundary by ISEE-1

Large electric field spikes of up to about 80 mV/m, at distances of seven to 23 earth radii, were detected within one minute of encountering the high-altitude plasma sheet boundary, as identified by energetic particle detectors. If these high-altitude events, whose strong electric fields occur in enhanced low-frequency turbulence and field-aligned current flow regions and are individually well-correlated with small-scale gradients in particle fluxes and small-scale currents, are mappings of the low-altitude electrostatic shocks, these data may be taken as evidence that poleward auroral field lines map to the boundary of the plasma sheet.

Cattell, C. A.↗
NASA NTRS1991

The Aries auroral modelling campaign - Characterization and modelling of an evening auroral arc observed from a rocket and a ground-based line of meridian scanners

A summary of the Aries experiments and results is presented with specific attention given to the tomographic analysis developed from ground-based photometric data. The instrumentation includes particle detectors, rocket photometers, plasma probes, and 1-deg meridian scanning photometers, and an all-sky TV system. The geophysical conditions during the observations are described including the auroral features and wavelengths, rocket trajectories, and the effectiveness of particle measurements. The tomographic inversion is explained with examples of rocket-photometer height data and contrasted with ground-based photometric data. The modeling techniques used to derive height profiles are described and indirectly compared to measured auroral intensities and intensity ratios. An enhancement of atomic oxygen is inferred from discrepancies with previous studies which confirm the difference between observed intensity ratios and modeled results.

Jones, A. V.↗
NASA NTRS2015

Badhwar-O'Neill 2014 Galactic Cosmic Ray Flux Model Description

The Badhwar-O'Neill (BON) Galactic Cosmic Ray (GCR) model is based on GCR measurements from particle detectors. The model has mainly been used by NASA to certify microelectronic systems and the analysis of radiation health risks to astronauts in space missions. The BON14 model numerically solves the Fokker-Planck differential equation to account for particle transport in the heliosphere due to diffusion, convection, and adiabatic deceleration under the assumption of a spherically symmetric heliosphere. The model also incorporates an empirical time delay function to account for the lag of the solar activity to reach the boundary of the heliosphere. This technical paper describes the most recent improvements in parameter fits to the BON model (BON14). Using a comprehensive measurement database, it is shown that BON14 is significantly improved over the previous version, BON11.

O'Neill, P. M.↗