The electron transfer process in field ionization
Electron transfer in ion microscope field ionization, analyzing band and periodic surface structure effects, ionization probability and collision formalism
Fonash, S. J.↗
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COMPARISON OF COMMERCIAL, SPHERICAL POWDER AND WIRE BUNDLE TUNGSTEN IONIZERS
Cesium ionization on porous tungsten structures in terms of neutral fraction, critical temperature, and flow rate
CESIUM ION↗
Calibration and simulation of ionization signal and electronics noise in the ICARUS liquid argon time projection chamber
The ICARUS liquid argon time projection chamber (LArTPC) neutrino detector has been taking physics data since 2022 as part of the Short-Baseline Neutrino (SBN) Program. This paper details the equalization of the response to charge in the ICARUS time projection chamber (TPC), as well as data-driven tuning of the simulation of ionization charge signals and electronics noise. The equalization procedure removes non-uniformities in the ICARUS TPC response to charge in space and time. This work leverages the copious number of cosmic ray muons available to ICARUS at the surface. The ionization signal shape simulation applies a novel procedure that tunes the simulation to match what is measured in data. The end result of the equalization procedure and simulation tuning allows for a comparison of charge measurements in ICARUS between Monte Carlo simulation and data, showing good performance with minimal residual bias between the two.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NAIRAS Model Updates and Improvements to the Prediction of the Ionizing Radiation Environment from the Earth's Surface to Geospace
- NAIRAS Model Description - Nowcast of Aerospace Ionizing RAdiation System (NAIRAS) Model - Running in real-time on LaRC computer cluster since 2011, results hosted on Space Environment Technologies server/website - Running in real-time at CCMC since 2020 - Key Model Features - Global ionizing radiation environment model - Physics-based HZETRN (High Charge (Z) and Energy TRaNsport) code - Real-time inclusion of solar energetic particle (SEP) radiation - Real-time solar-magnetospheric effects on radiation (cutoff model by Kress et al. [2004, 2010]) - New/Current Model Development - Improved SEP dose nowcast and forecast - Extend to low-Earth orbit (LEO) environment - Single-Event Effects (SEE) radiation risk assessment quantities - Run-on-Request (RoR) @ CCMC
Christopher J. Mertens↗
Field ionization electrodes Patent
Electrodes having array of small surfaces for field ionization
Barrington, A. E.↗
Automatic control systems for ion engines.
Automatic control systems for electron bombardment and contact ion engines
ION ENGINE↗
High-voltage breakdown initiated by particle impact.
High voltage breakdown in electrode discharge initiated by particle impact in hypothesis of Cranberg
PARTICLE COLLISION↗
Luminescence of solids excited by surface recombination of atoms. iv - mechanisms of excitation and luminescence.
Excitation and luminescence of solids subjected to surface-catalyzed atom recombination and photoexcitation
SURFACE IONIZATION↗
Luminescence of solids excited by surface recombination of atoms. v - quantitative dependence of luminescence response on oxygen- and nitrogen-atom densities.
Luminescence response of solids excited by surface recombination of atoms and dependence on atomic density
GAS DENSITY↗
Ion thrustor electrode surface physics study
Cesium surface contact ionization electrostatic thrustors
ION EMISSION↗
Silicon surface damage due to gamma radiation.
Silicon surface damage, discussing low energy gamma irradiation effect on bulk lifetime and recombination velocity
GAMMA RADIATION↗
Radiation induced nonlinear degradation of transistor gain
Ionization induced surface effects on transistors
Source record↗
Cooling of pulsars
Cooling rates are calculated for superfluid neutron stars of about one solar mass and 10 km radius, with magnetic fields from zero to about 10 to the 14th power Gauss, when possible internal friction effects are neglected. The results show that most old pulsars are so cold that thermal ionization of surface atoms would be negligible. At an age of a million years and with canonical magnetic fields of 10 to the 12th power Gauss, the estimated stellar surface temperature is several thousand to a hundred thousand degrees. However, if we neglect magnetic fields and superfluid states of nucleons, the same surfaces would be about a million degrees.
Tsuruta, S.↗
Cooling of dense stars
Cooling rates were calculated for neutron stars of about one solar mass and 10 km radius, with magnetic fields from zero to about 10 to the 14th power gauss, for extreme cases of maximum and zero superfluidity. The results show that most pulsars are so cold that thermal ionization of surface atoms would be negligible. Nucleon superfluidity and crystallization of heavy nuclei were treated quantitatively, and more realistic hadron star models were chosen. Cooling rates were calculated for a stable hyperon star near the maximum mass limit, a medium weight neutron star, and a light neutron star with neutron-rich heavy nuclei near the minimum mass limit. Results show that cooling rates are a sensitive function of density. The Crab and Vela pulsars are considered, as well as cooling of a massive white dwarf star.
Tsuruta, S.↗
Development of an apparatus for obtaining molecular beams in the energy range from 2 to 200 eV
The formation and detection of molecular beams obtained by charge exchange from a low-energy ion source is discussed. Dispersion in energy of the ion source was measured and problems concerning detection of neutral beams were studied. Various methods were used, specifically secondary electron emissivity of a metallic surface and ionization of a gas target with a low ionization voltage. The intensities of neutral beams as low as 10 eV are measured by a tubular electron multiplier and a lock-in amplifier.
Clapier, R.↗
Solar concentrator degradation in Low Earth Orbit (LEO)
The use of parabolically or spherically-shaped mirrors is being considered in order to increase the solar energy intensity on solar cells. Their use will significantly decrease the size and number of the cells needed for a particular application, hence the total array cost. Questions arise, however, regarding the long-term (five to ten years) efficiency of these devices. Performance degradation of the mirror surfaces might result from known hostile elements in the low earth orbit (LEO) environment (150-350 nautical miles). The degradation issue is addressed in light of present knowledge of this environment. The following characteristics of the LEO environment are identified for study: (1) the vacuum of space; (2) sputtering by the residual atoms and particles in space; (3) solar electromagnetic radiation; (4) contamination of the mirror surface; (5) atomic oxygen interactions with the surface; (6) bombardment of the surface by meteoroids; and (7) irradiation of the surface by ionizing particles (protons). Using the best available information for the magnitudes of the necessary quantities, a mathematical analysis was carried out, where possible, to determine the degradation in reflectance or other loss caused by each characteristic. Otherwise, reasonable estimates are made of corresponding losses, based on already published data.
Thomas, R. G.↗
An assessment of the potential of continuous-wave ranging for measuring the distance to a highly reflective, infinite sheet
The feasibility of a continuous-wave, distance-measuring technique for measuring the distance from a spacecraft antenna to a highly ionized plasma surface is examined. The reflection coefficient angle is computed for several aperture models. It is concluded that aperture size and the presence of a nonablating dielectric cover over the antenna are critical factors.
Hearn, C. P.↗