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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Gridless retarding potential analyzer for use in very-low-energy charged particle detection

The theory of the hyperbolic retarding potential analyzer in the electrostatic mode is developed in detail and verified in the laboratory. A monoenergetic electron beam is used for the laboratory investigation. The analyzer (acronym HARP) has advantages over other conventional electrostatic analyzers; among them are less contact potential influence and high throughput because of the symmetry shape of the analyzer. The most useful application of the HARP is in detecting low-energy charged particles. A sample of low-energy particle data obtained in the earth's ionosphere is given.

Shyn, T. W.↗
NASA NTRS1980

New methods to detect particle velocity and mass flux in arc-heated ablation/erosion facilities

Arc-heated flow facilities with injected particles are used to simulate the erosive and ablative/erosive environments encountered by spacecraft re-entry through fog, clouds, thermo-nuclear explosions, etc. Two newly developed particle diagnostic techniques used to calibrate these facilities are discussed. One technique measures particle velocity and is based on the detection of thermal radiation and/or chemiluminescence from the hot seed particles in a model ablation/erosion facility. The second technique measures a local particle rate, which is proportional to local particle mass flux, in a dust erosion facility by photodetecting and counting the interruptions of a focused laser beam by individual particles.

Brayton, D. B.↗
NASA NTRS1996

Micron-Sized Particles Detected in the Vicinity of Jupiter by the Voyager Plasma Wave Instruments

Wideband waveform data obtained by the plasma wave instruments onboard the Voyager 1 and 2 spacecraft have been used to study micron-sized dust particles in the vicinity of Jupiter. The technique used was developed during the flybys of Saturn, Uranus, and Neptune, and makes use of the fact that a particle striking the spacecraft at 10-20 km/s causes a voltage pulse in the plasma wave receiver. The waveform of the voltage pulse is much different than the waveform of plasma waves and provides a highly reliable method of detecting micron-sized dust particles. Although the dust impact rate observed in the vicinity of Jupiter is much lower than the rates at Saturn, Uranus, and Neptune, the particles are easily detectable. Approximately 1200 48-second frames of wideband waveform data were examined in the vicinity of Jupiter. Dust impact signatures were found in approximately 20% of these frames. The peak impact rates are about 1 impact per second, and the peak number densities are about 10(exp -5) m(exp -3). Most of the impacts occurred near the equatorial plane at radial distances less than about 35 R(sub j) from Jupiter. Analysis of the detection threshold indicates that the particles have masses greater than 10(exp -11) g, which corresponds to particles with diameters of a few micrometers or larger.

Tsintikidis, D.↗
NASA NTRS1972

Particle detection by a light-scattering technique

Instrument measures concentration of small particles in aqueous medium in terms of amount of light scattered and degree to which light transmission is attenuated. Sensitivity to small particles is optimized because both scattered and transmitted illumination levels are detected by photodiodes.

Kormanyos, S.↗
NASA NTRS1991

Micron-sized particles detected near Neptune by the Voyager 2 plasma wave instrument

Observations and an analysis are presented of the micron-sized-particle impacts observed by the plasma-wave instrument aboard the Voyager 2. After a detailed description of signals produced by the dust impacts, the impact noise is interpreted in terms of the number density and mass of the particles. The likely sources of the particles are discussed.

Gurnett, D. A.↗
NASA NTRS1972

Particle detection with intensified laser beam

Application of external and laser output mirrors to produce intensified light beam for measurement of light scattered by dispersed particles is described. Use of fiber optics bundles to collect light is discussed. Diagram of equipment and principles of operation are presented.

Knollenberg, R. G.↗
NASA NTRS1988

Correlation studies on surface particle detection methods

The accurate determination of dust levels on optical surfaces is necessary to assess sensor system performance. A comparison study was made on several particle measurement methods including those based on direct imaging and light scattering. The effectiveness of removing the particles from the surface prior to determining particle size distributions was also assessed. These studies revealed that some methods, especially those requiring particle removal before analysis, are subject to large systematic errors affecting particle size distributions. Thus, an understanding of the particle measurement methods employed is necessary before any surface cleanliness or obstruction value assignments are accepted as true representations of an optical surface contamination condition.

Peterson, Ronald V.↗
NASA NTRS2000

Delta-doped hybrid advanced detector for low energy particle detection

A delta-doped hybrid advanced detector (HAD) is provided which combines at least four types of technologies to create a detector for energetic particles ranging in energy from hundreds of electron volts (eV) to beyond several million eV. The detector is sensitive to photons from visible light to X-rays. The detector is highly energy-sensitive from approximately 10 keV down to hundreds of eV. The detector operates with milliwatt power dissipation, and allows non-sequential readout of the array, enabling various advanced readout schemes.

Cunningham, Thomas J.↗
NASA NTRS2002

Delta-doped hybrid advanced detector for low energy particle detection

A delta-doped hybrid advanced detector (HAD) is provided which combines at least four types of technologies to create a detector for energetic particles ranging in energy from hundreds of electron volts (eV) to beyond several million eV. The detector is sensitive to photons from visible light to X-rays. The detector is highly energy-sensitive from approximately 10 keV down to hundreds of eV. The detector operates with milliwatt power dissipation, and allows non-sequential readout of the array, enabling various advanced readout schemes.

Cunningham, Thomas J.↗
DOE OSTI2026

Single-particle detection of enhanced polarizability in Au-decorated semiconducting nanorods via scanning dielectric microscopy

Hybrid nanostructures that combine semiconducting and metallic components offer great potential for photothermal therapy, optoelectronics, and sensing, by integrating tunable optical properties with enhanced light absorption and charge transport. Boosting the integrated performance of these hybrid systems demands techniques capable of probing local variations of the physical properties inaccessible to bulk analysis. Here, we report the single-particle dielectric characterization of hybrid, semiconducting bismuth sulfide (Bi 2 S 3 ) nanorods (NR) decorated with metallic Au nanoparticles (NP), employing scanning dielectric microscopy, which uses electrostatic force microscopy in combination with finite-element numerical simulations. We reveal a pronounced enhancement in the local dielectric response of Bi2S3 upon Au decoration, attributed to interfacial polarization and electron transfer from Au to the Bi 2 S 3 matrix, thus suggesting a enhanced metallic-like polarizability at the single-particle level. Numerical simulations show that the response is dominated by the vertical component of the permittivity and that the decorating metallic Au NP produce only moderate shielding of the semiconductor Bi 2 S 3 NR core, indicating that the large increase in the dielectric response originates primarily from intrinsic modifications within the NR. Overall, these findings provide direct insight into structure–property relationships at the single-particle level, supporting the rational design of advanced hybrid nanostructures with tailored electronic functionalities.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Superconducting qubits for particle detection and fundamental tests of quantum mechanics

Many fundamental questions at the interface of quantum mechanics, gravity, and measurement remain relatively unexplored in the laboratory. These include whether spatial superpositions experience gravitational redshift, how the quantum Zeno effect propagates through entangled systems, and whether quantum information is globally conserved or fundamentally lost during measurement-induced wavefunction collapse. In this colloquium, I will discuss how superconducting qubits—developed primarily for quantum computing—can be repurposed as ultra sensitive detectors to probe these questions and to search for low-energy particle interactions. I will describe my work at Fermilab on stabilizing these devices to the level required for next-generation qubit-based sensors. This includes mitigating decoherence from infrared radiation and cosmic rays, using machine-learning techniques to accelerate superconducting qubit design, and leveraging the quantum Zeno effect to improve coherence times and suppress qubit frequency fluctuations. Together, these advances point toward a new class of quantum sensors capable of testing fundamental physics.

Seidel, Olivia [Fermilab]↗
NASA NTRS1986

Dust particles detected near Giacobini-Zinner by the ICE plasma wave instrument

During the ICE flyby of Giacobini-Zinner the plasma wave instrument detected numerous impulsive signals caused by dust impacts on the spacecraft. Most of the impacts occurred within 30,000 km of the comet. The impact rate averaged over the inbound and outbound legs varies approximately as 1/r-squared, as would be expected for an isotropic constant velocity radial outflow. Small differences between the inbound and outbound legs exist which may be indicative of azimuthal variations in the dust production rate. A simple model of the impact ionization and charge collection by the antenna indicates that the particles have a mass on the order of 10 to the -12 to 10 to the -10th gm, corresponding to particles with radii of a few microns.

Gurnett, D. A.↗
NASA NTRS1994

A revised analysis of micron-sized particles detected near Saturn by the Voyager 2 plasma wave instrument

The impulsive noise that the plasma wave and radio astronomy instruments detected during the Voyager 2 swing by Saturn was attributed to dust grains striking the spacecraft. This report presents a reanalysis of the dust impacts recorded by the plasma wave instrument using an improved model for the response of the electric antenna to dust impacts. The fundamental assumption used in this analysis is that the voltage induced on the antenna is proportional to the mass of the impacting grain. Using the above assumption and the antenna response constants used at Uranus and Neptune, the following conclusions can be reached. The primary dust distribution consists of a 'disk' of particles that coincides with the equator plane and has a north-south thickness of 2-Delta zeta = 962 km. A less dense 'halo' with a north-south thickness of 2-Delta zeta = 3376 km surrounds the primary distribution. The dust particle sizes are of the order of 10 microns, assuming a mass density of 1 g/cu cm. The corresponding particle masses are of the order of 10(exp -9) g, and maximum number densities are of the order of 10(exp -2)/cu m. Most likely, the G ring is the dominate source since the particles were observed very close to that ring, namely at 2.86 R(sub S). Other sources, like nearby moons, are not ruled out especially when perturbations due to electromagnetic forces are included. The calculated optical depth differs by about a factor of 2 from photometric studies. The current particle masses, radii, and the effective north-south thickness of the particle distribution are larger than what Gurnett et al. (1983) reported by about 2, 1, and 1 orders of magnitude, respectively. This is attributed to the fact that the collection coefficient used in this study is smaller than what was used in Gurnett et al.'s earlier publication.

Tsintikidis, D.↗
DOE OSTI2025

X-Ray and Particle Detection With the Si(Li) Tracker Module of the GAPS Experiment

Here, this work describes the architecture and the experimental results from the characterization of the lithium-drifted silicon (Si(Li)) detector module, which constitutes the building block of the tracker in the general antiparticle spectrometer (GAPS) experiment to search for dark matter. The instrument is designed for the identification of low-energy cosmic anti-nuclei (antiprotons, antideuterons, and antihelium) to be performed during an Antarctic long-duration balloon flight scheduled for late 2025. The GAPS Si(Li) tracker, that is the core of the instrument, is the assembly of 252 modules, each comprised of four Si(Li) detectors and a full custom-integrated circuit designed for detector readout and produced in a commercial 180-nm planar CMOS technology. A general overview of the detector module architecture and its components is provided, together with a description of the test setup and the experimental results obtained from the characterization of the low-noise analog readout channel. In order to verify the effective operation of the entire module, results concerning the detection of X-rays from a 241Am source and cosmic muons are also provided.

Manghisoni, Massimo [Università di Bergamo (Italy)↗