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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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Linear free energy relationship between benzoyl and acetyl ion intensities in mass spectra of benzo- and acetophenones explained by kinetic argument
Competing alternative pathways for formation of particular ion in mass spectra of substituted benzophenones
Energy and angular distributions of neutral atoms and charge-exchange ions from mercury electron bombardment thrustor, determining particle effluxes
Power transfer to ion cyclotron waves in two species plasma
Energy and angular distributions of neutral atoms and charge-exchange ions from mercury electron bombardment thrustor, determining particle effluxes
Simultaneous OGO-2 observations of light ion trough and VLF cutoff
Relaxation effects of rare earth ions in crystals
Auroral ion distribution and conversion of oxygen protons to nitric oxide protons
Auroral ion composition and chemistry from rocket-borne mass spectrometer measurements, investigating oxygen density and green line excitation
Measuring intermittent enhancement of blinking effect upon addition of neon to imaging gas in helium-tungsten field-ion microscope
An asymptotic solution of the Boltzmann equation is developed for ICR absorption, without restrictions on the ion-neutral collision frequency or mass ratio. Velocity dependence of the collision frequency causes deviations from Lorentzian line shape.
Non-LTE plasmas are ubiquitous in objects studied in the UV and X-ray energy bands. Collisional and photoionization cross sections for atoms and ions are fundamental to our ability to model such plasmas. Modeling is key in the X-ray band, where detector properties and limited spectral resolution limit the ability to measure model-independent line strengths, or other spectral features. Much of the motivation for studying such collisions and many of the tools, are not new. However, the motivation for such studies and their applications, have been affected by the advent of X-ray spectroscopy with the gratings on Chandra and XMM-Newton. In this talk I will review this motivation and describe the tools currently in use for such studies. I will also describe some current unresolved problems and the likely future needs for such data.
Accurate estimates of electron-capture cross sections at energies relevant to energetic neutral atom (ENA) modeling (approx few MeV per nucleon) and for multi-electron ions must rely on first-principles approaches and/or detailed quantum-mechanical simulation of the collision process. Kuang's semi-classical approach offers a middle-ground, elegant and efficient way to arrive at these estimates. We shall present a sample application and current progress in applying and extending Kuang's formalism to ENA modeling.
Introduction - Electromagnetic cyclotron waves (ECWs) near the proton cyclotron frequency (f_pc) and higher than Alfvén wave frequency - Ion cyclotron waves (ICWs): left-hand (LH) polarized in plasma frame - Magnetosonicwaves: right-hand (RH) polarized in plasma frame - They are important because the absorption of fluctuating magnetic field energy starting at f_pc has been demonstrated extensively - Before PSP era, intermittent observations of such ECWs in quiet solar wind have been reported in Behannon (1976), Tsurutani et al. (1994), Jian et al. (2009, 2010, 2014), Boardsen et al. (2015), Wicks et al. (2016), etc
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