Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “solar physics”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Europe gets aboard the Shuttle

A series of experiments directed by NASA for the European Space Agency's Spacelab are planned for early 1983. Spacelab 1 is scheduled to carry equipment for upper atmosphere research and for experiments in plasma and solar physics, medicine, and thermodynamics. Spacelab 2 will provide equipment for research in astronomy, high-energy physics, astrophysics, and solar physics. Spacelab 3 will be equipped to study materials processing in space, biological tests, and cloud physics. Spacelab is modular and reusable, with the planned life equal to 50 missions. The Space Shuttle will carry a Spacelab with scientific equipment of up to 8800 kg into orbits ranging in altitude from 160 to 1100 km and transmitting data at up to 50 Mb/s. The cost of launching a Shuttle/Spacelab mission is estimated at $28 million.

Moye, J. E.↗
NASA NTRS1995

Visualization of International Solar-Terrestrial Physics Program (ISTP) data

The International Solar-Terrestrial Physics Program (ISTP) is a multispacecraft, multinational program whose objective is to promote further understanding of the Earth's complex plasma environment. Extensive data sharing and data analysis will be needed to ensure the success of the overall ISTP program. For this reason, there has been a special emphasis on data standards throughout ISTP. One of the key tools will be the common data format (CDF), developed, maintained, and evolved at the National Space Science Data Center (NSSDC), with the set of ISTP implementation guidelines specially designed for space physics data sets by the Space Physics Data Facility (associated with the NSSDC). The ISTP guidelines were developed to facilitate searching, plotting, merging, and subsetting of data sets. We focus here on the plotting application. A prototype software package was developed to plot key parameter (KP) data from the ISTP program at the Science Planning and Operations Facility (SPOF). The ISTP Key Parameter Visualization Tool is based on the Interactive Data Language (IDL) and is keyed to the ISTP guidelines, reading data stored in CDF. With the combination of CDF, the ISTP guidelines, and the visualization software, we can look forward to easier and more effective data sharing and use among ISTP scientists.

Kessel, Ramona L.↗
NASA NTRS1986

The Advanced Solar Observatory. Executive summary

The topics covered include the following: (1) an overview of the Advanced Solar Observatory program and instrumentation; (2) the scientific motivation for the Advanced Solar Observatory; (3) a brief review of recent advances in solar physics; (4) a scientific strategy for solar physics; (5) the scientific objectives of the Advanced Solar Observatory; (6) the configuration of the Advanced Solar Observatory; (7) the development of the Advanced Solar Observatory; (8) the performance of the Advanced Solar Observatory; (9) scientific operation of the Advanced Solar Observatory; and (10) present status of the Advanced Solar Observatory. A compilation of major scientific problems in solar physics is presented in the appendix.

Walker, A. B. C., Jr.↗
NASA NTRS1998

Solar Flare Physics

We have continued our previous efforts in studies of fourier imaging methods applied to hard X-ray flares. We have performed physical and theoretical analysis of rotating collimator grids submitted to GSFC(Goddard Space Flight Center) for the High Energy Solar Spectroscopic Imager (HESSI). We have produced simulation algorithms which are currently being used to test imaging software and hardware for HESSI. We have developed Maximum-Entropy, Maximum-Likelihood, and "CLEAN" methods for reconstructing HESSI images from count-rate profiles. This work is expected to continue through the launch of HESSI in July, 2000. Section 1 shows a poster presentation "Image Reconstruction from HESSI Photon Lists" at the Solar Physics Division Meeting, June 1998; Section 2 shows the text and viewgraphs prepared for "Imaging Simulations" at HESSI's Preliminary Design Review on July 30, 1998.

Schmahl, Edward J.↗
NASA NTRS1981

Interactive data analysis for astronomy Shuttle experiments at Goddard Space Flight Center

The eye as an efficient selection device for determining what is important in astronomical imagery can be greatly aided by the computer. A suitable facility, called the Interactive Astronomical Data Analysis Facility (IADAF), has been developed for the display and analysis of astronomical imagery by the Laboratory for Astronomy and Solar Physics. The Laboratory for Astronomy and Solar Physics currently has approval to fly two experiments on Spacelab. The Solar Extreme Ultraviolet Telescope (SEUTS) is to be used for the study of several fundamental problems of solar physics. The Ultraviolet Image Telescope for Astronomical Investigations (UIT) is to provide direct imagery of selected fields of view throughout the sky. A description is given of IADAF, taking into account its 16-bit computer and the COMTAL image processing display system. The use of IADAF by SEUTS and UIT is discussed.

Klinglesmith, D. A., III↗
NASA NTRS1991

Solar astronomy

An overview is given of modern solar physics. Topics covered include the solar interior, the solar surface, the solar atmosphere, the Large Earth-based Solar Telescope (LEST), the Orbiting Solar Laboratory, the High Energy Solar Physics mission, the Space Exploration Initiative, solar-terrestrial physics, and adaptive optics. Policy and related programmatic recommendations are given for university research and education, facilitating solar research, and integrated support for solar research.

Rosner, Robert↗
NASA NTRS1992

On the physics of waves in the solar atmosphere: Wave heating and wind acceleration

In the area of solar physics, new calculations of the acoustic wave energy fluxes generated in the solar convective zone was performed. The original theory developed was corrected by including a new frequency factor describing temporal variations of the turbulent energy spectrum. We have modified the original Stein code by including this new frequency factor, and tested the code extensively. Another possible source of the mechanical energy generated in the solar convective zone is the excitation of magnetic flux tube waves which can carry energy along the tubes far away from the region. The problem as to how efficiently those waves are generated in the Sun was recently solved. The propagation of nonlinear magnetic tube waves in the solar atmosphere was calculated, and mode coupling, shock formation, and heating of the local medium was studied. The wave trapping problems and evaluation of critical frequencies for wave reflection in the solar atmosphere was studied. It was shown that the role played by Alfven waves in the wind accelerations and the coronal hole heating is dominant. Presently, we are performing calculations of wave energy fluxes generated in late-type dwarf stars and studying physical processes responsible for the heating of stellar chromospheres and coronae. In the area of physics of waves, a new analytical approach for studying linear Alfven waves in smoothly nonuniform media was recently developed. This approach is presently being extended to study the propagation of linear and nonlinear magnetohydrodynamic (MHD) waves in stratified, nonisothermal and solar atmosphere. The Lighthill theory of sound generation to nonisothermal media (with a special temperature distribution) was extended. Energy cascade by nonlinear MHD waves and possible chaos driven by these waves are presently considered.

Musielak, Z. E.↗
NASA NTRS1976

Report on the solar physics-plasma physics workshop

The paper summarizes discussions held between solar physicists and plasma physicists on the interface between solar and plasma physics, with emphasis placed on the question of what laboratory experiments, or computer experiments, could be pursued to test proposed mechanisms involved in solar phenomena. Major areas discussed include nonthermal plasma on the sun, spectroscopic data needed in solar plasma diagnostics, types of magnetic field structures in the sun's atmosphere, the possibility of MHD phenomena involved in solar eruptive phenomena, the role of non-MHD instabilities in energy release in solar flares, particle acceleration in solar flares, shock waves in the sun's atmosphere, and mechanisms of radio emission from the sun.

Sturrock, P. A.↗
NASA NTRS1982

The OSS-1/STS-3 mission

Integration, test, flight operations, program and science management, and experiment results from the OSS-1/STS-3 flight are reviewed. The experimental pallet, manufactured by ESA members, carried instrumentation for astronomy, space plasma studies, physics, planetology, solar physics, and life sciences. The ability of the equipment to operate in a worst-case Orbiter thermal environment was tested, as was the plasma environment around the Orbiter. The solar UV spectral irradiance monitor microprocessor was found to reset concurrently with start-up of the Shuttle hydraulic pumps. Degradations were also observed in one of the three solar flare X ray polarimeter modules, the thermal cannister experiment microprocessor, and the scientific data recorder no. 2. The Orbiter was determined to perform well during firing of an electron beam. A contamination monitor recorded matter accretion to be dependent on the solar orientation of the Orbiter. Finally, the distribution of the responsibilities and tasks for mission management are reviewed.

Kissin, K.↗
DOE OSTI2022

A next-generation liquid xenon observatory for dark matter and neutrino physics

The nature of dark matter and properties of neutrinos are among the most pressing issues in contemporary particle physics. The dual-phase xenon time-projection chamber is the leading technology to cover the available parameter space for weakly interacting massive particles, while featuring extensive sensitivity to many alternative dark matter candidates. These detectors can also study neutrinos through neutrinoless double-beta decay and through a variety of astrophysical sources. A next-generation xenon-based detector will therefore be a true multi-purpose observatory to significantly advance particle physics, nuclear physics, astrophysics, solar physics, and cosmology. This review article presents the science cases for such a detector.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRS1993

Recondensation in the early solar system: Physical conditions and source material

Many physical processes in the solar nebula led to fractionation of the gaseous phase of the preplanetary material. Some of these processes are listed with corresponding type of fractionation in terms of Rock/Ice/Gas. Recondensation from fractionated gas phase yields different compositions of condensates. In some detail, one type of fractionation is considered: impact heating with evaporation and subsequent recondensation of material during intercollisions of planetesimals. For thermodynamical simulation of recondensation in such a process one needs (1) P-T parameters and (2) some initial source material to be heated, evaporated, and recondensed. These two problems are addressed.

Vityazev, A. V.↗
NASA NTRS1972

Solar-terrestrial physics.

The work is concerned with solar influences on the earth's upper atmosphere and electromagnetic environment partly through solar ultraviolet and X rays, but particularly through corpuscular radiations. The sun and interplanetary space, the internal structure and magnetic field of the earth, the terrestrial atmosphere and photochemistry, and the dynamics of the upper atmosphere and dynamo action are considered. The formation of the magnetosphere, energetic particles, plasma, and electromagnetic waves in the magnetosphere, solar storms and their extension into interplanetary space, and magnetospheric storms are treated.

Akasofu, S.-I.↗
NASA NTRS1991

Solar-Terrestrial Physics in the 1990s: Key Science Objectives for the IACG Mission Set

The International Solar-Terrestrial Physics (ISTP) program is an internationally coordinated multi-spacecraft mission that will study the production of the supersonic magnetized solar wind, its interaction with the Earth's magnetosphere, and the resulting transport of plasma, momentum and energy through the magnetosphere and into the ionosphere and upper atmosphere. The mission will involve l4spacecraft to be launched between 1992 and 1996, along with complementary ground-based observations and theoretical programs. A list of the spacecraft, their nominal orbits, and responsible agencies is shown.

Source record↗
NASA NTRS1993

Filters for the International Solar Terrestrial Physics (ISTP) mission far ultraviolet imager

The far ultraviolet (FUV) imager for the International Solar Terrestrial Physics (ISTP) mission is designed to image four features of the aurora: O I lines at 130.4 nm and 135.6 nm and the N2 Lyman-Birge-Hopfield (LBH) bands between 140 nm - 160 nm (LBH long) and 160 nm - 180 nm (LBH long). In this paper we report the design and fabrication of narrow-band and broadband filters for the ISTP FUV imager. Narrow-band filters designed and fabricated for the O I lines have a bandwidth of less than 5 nm and a peak transmittance of 23.9 percent and 38.3 percent at 130.4 nm and 135.6 nm, respectively. Broadband filters designed and fabricated for LBH bands have the transmittance close to 60 percent. Blocking of out-of-band wavelengths for all filters is better than 5x10(exp -3) percent with the transmittance at 121.6 nm of less than 10(exp -6) percent.

Zukic, Muamer↗
NASA NTRS1984

Recent advances in solar radio physics

High spatial resolution microwave observations of solar active regions, coronal loops and flares are reviewed. Observations of preflare active regions are presented; in particular the interpretations of reversal of polarization at the flare site and the role of newly emerging flux in triggering the onset of flares are considered. The spatial locations of microwave burst emitting regions are discussed; loops or arcades of loops appear to be the sites of flare energy release in microwave bursts. Direct observational evidence of magnetic reconnection as the primary cause of acceleration of electrons in microwave bursts is provided.

Kundu, M. R.↗