SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS

A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 43, ISSUE 25 - DECEMBER 16, 2005

90 ASTROPHYSICS
Includes cosmology; celestial mechanics; space plasmas; and interstellar and interplanetary gases and dust.

20050240970 Department of Energy, Washington, DC USA, National Science Foundation, Washington, DC USA

Discovering the Quantum Universe: The Role of Particle Colliders

January 2005; 50 pp.; In English Report No.(s): PB2006-101154; No Copyright; Avail.: National Technical Information Service (NTIS)

This report explores in successively greater depth the role that accelerators will play in discovering the quantum universe. Chapter 1 introduces three discovery themes. Chapter 2 elucidates the meaning of the three themes in the context of the Large Hadron Collider and the International Inear Collider. Chapter 3 presents a discussion in depth of the physics of the Higgs particle and supersymmetry; the search for dark matter; and the quest for ultimate unification. NTIS

Exploration; Universe

20050241682 Lawrence Livermore National Lab., Livermore, CA USA

Laboratory Studies of the Fe K-Shell Emission

Beiersdorfer, P.; Dec. 27, 2004; 16 pp.; In English Report No.(s): DE2005-15014620; UCRL-PROC-208771; No Copyright; Avail.: Department of Energy Information Bridge

An overview is given of measurements of the Fe K-shell spectrum from low-density laboratory sources.

The measurements include wavelengths, electron-impact collision cross sections, innershell ionization phenomena, dielectronic recombination resonance strengths, charge exchange recombination, electron beam polarization effects, resonance excitation, and radiative cascade contributions.

K-shell spectra have now also been obtained with microcalorimeters, including microcalorimeter arrays that are twins of the ASTRO-E and ASTRO-E2 missions, which illustrate typical resolving powers and spectral capabilities.

NTIS

Electron-Ion Recombination; Ionization Cross Sections; Resonance Charge Exchange

20050241968 Lawrence Livermore National Lab., Livermore, CA USA

Summary of the Meeting

Lovelace, R. V. E.; Ryutov, D. D.; Dec. 16, 2003; 8 pp.; In English Report No.(s): DE2005-15013788; UCRL-PROC-201503; No Copyright; Avail.: Department of Energy Information Bridge

This was a meeting between two large groups of researchers: astrophysicists and space physicists, on the one hand, and laboratory plasma physicists, on the other. The meeting has clearly demonstrated a growing mutual interest of these two groups: presenters of one group tried to make their talks understandable to another group, discussions were very lively, and a number of points for further joint effort have been identified. This was a timely meeting in view of the explosion of observational data from new space and ground based instruments. New phenomena have been observed and/or understood more clearly, including gamma ray burst sources, the Sunyaev-Zeldovich effect, the anisotropy of the cosmic microwave background, high magnetic field pulsars or magnetars, solar acoustic spectroscopy, ultra luminous star burst galaxies, and many others. Specific talks and posters covered essentially all areas of plasma physics related to astrophysics and space physics, from dusty plasmas, through reconnection physics, to high-energy-density phenomena. Some talks were related to the development of the conceptual framework of the plasma physics, like modern models of the hydrodynamic turbulence, magnetic dynamos, Hall magnetohydrodynamics, and hydrodynamical and magnetohydrodynamic instabilities in rotating systems. NTIS

Plasma Physics; Atmospheric Physics; Astrophysics; Spectroscopy

20050241969 Lawrence Livermore National Lab., Livermore, CA USA

Laboratory Studies of X-Ray Emission from Fe L-Shell Transitions and Their Diagnostic Utility

Brown, G. V.; Beiersdorfer, P.; Chen, H.; Scofield, J. H.; Boyce, K. R.; Jan. 19, 2005; 16 pp.; In English Report No.(s): DE2005-15014492; UCRL-CONF-209097; No Copyright; Avail.: Department of Energy Information Bridge

Non-terrestrial objects are home to complex, dynamic, intriguing environments. High-resolution x-ray spectra from these sources measured by satellites such as the Chandra x-ray Observatory, XMM-Newton, the Solar Maximum Mission, and the soon-to-be-launched Astro-E2 provide a means for understanding the physics governing these sources. Especially rich is the x-ray emission from L-shell transitions in highly-charged iron ions. This emission is the source of a variety of diagnostics whose utility lies in the accuracy of the atomic data employed to model the x-ray spectra either globally or using ratios of key emission lines. The atomic data used to describe these diagnostics are generally provided by large theoretical calculations and benchmarked by laboratory data. I will discuss the laboratory measurements of Fe L-shell x-ray emission, past, present, and future, how these data are being implemented in spectral modeling packages, and how models are being built using data obtained exclusively in the laboratory. NTIS

Emission; X Rays

20050242994 Naval Postgraduate School, Monterey, CA USA

A Novel Photovoltaic Power Converter for Military and Space Applications

Fernandez, Randyll R. M., Jr; Sep. 1, 2005; 97 pp.; In English; Original contains color illustrations Report No.(s): AD-A439411; No Copyright; Avail.: Defense Technical Information Center (DTIC)

The purpose of this thesis is to consider PhotoVoltaic Power Converter (PVPC) technology, developed by Atira Technologies , and its prospects for military and space applications. This research will validate the hypothesis that PVPC technology enables a solar power system to produce usable power during low-and no-light conditions which standard solar power systems fail to provide. Solar cell panels are exposed to sunlight at different angles and with variable intensity, therefore the resulting output power varies depending on the illumination angle as well as the light intensity of each panel. Atira Technologies devised a novel buck-boost converter that is specifically designed to track the maximum power point of each solar panel. This would provide a significant increase in the overall available power by utilizing a switching topology in a subdued lighting condition. Although a small amount of power is generated, given enough time, a battery will reach its full charge, compared to no additional charging if the battery is using a panel without the circuit. In addition, this research will also show the vital sustaining information to substantiate PVPC's claim of usefulness and effectiveness to allow for longer time on station both in the field and in space so it can extend its missions. DTIC

Military Technology; Photovoltaic Effect; Power Converters; Solar Energy; Technology Utilization

20050243167 Aerospace Corp., Los Angeles, CA USA

Low-Altitude Distribution of Radiation Belt Electrons

Selesnick, R. S.; Looper, M. D.; Albert, J. M.; Nov. 10, 2004; 12 pp.; In English Contract(s)/Grant(s): Proj-1010 Report No.(s): AD-A439680; AFRL-VS-HA-TR-2004-1205; No Copyright; Avail.: CASI: A03, Hardcopy

A numerical simulation of the low-altitude electron radiation belt is described. It includes dependences on the electron's bounce and drift phases, equatorial pitch angle, and kinetic energy in the range of 1 to several MeV at L = 3.5. Physical processes in addition to the adiabatic electron motion are pitch angle diffusion and backscattering from a realistic model atmosphere. Quasi-linear diffusion coefficients are calculated from a model of the whistler mode plasmaspheric hiss wave intensity. Comparisons of the simulation results with electron data from a low-altitude satellite show that the model accounts for the main features of the electron spatial distribution during selected periods of differing geomagnetic activity. DTIC

Electrons; Low Altitude; Radiation Belts; Simulation; Spatial Distribution

Source: NASA.