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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 217 records · Page 12

Observation of the core of the Perseus cluster with the Einstein solid state spectrometer: Cooling gas and elemental abundances

Solid State Spectrometer observations of the core of the Perseus cluster have resulted in the detection of X-ray emission lines due to Si, S, and Fe. Analysis of the spectrum indicates that the X-ray emission has at least two characteristic temperatures. This is interpreted in the framework of radiative accretion in the core of the cluster. The derived parameters are a cooling time tc less than 2 x 109 yrs for the low temperature gas, a mass accretion rate of approximately 300 Mo/yr and a characteristic size of 10 to 20 Kpc for the cool gas. The Fe abundance in the core, approximately 0.4, is similar to the Fe abundance averaged over the whole cluster indicating that Fe emission is not strongly concentrated about NGC 1275. The Si and S abundances are consistent with solar values.

Mushotzky, R. F.↗

Observation of the core of the Perseus cluster with the Einstein solid state spectrometer - Cooling gas and elemental abundances

Solid State Spectrometer observations of the core of the Perseus cluster have resulted in the detection of X-ray emission lines due to Si, S, and Fe. Analysis of the spectrum indicates that the X-ray emission has at least two characteristic temperatures. This is interpreted in the framework of radiative accretion in the core of the cluster. The derived parameters are a cooling time less than or approximately equal to 2 x 10 to the ninth years for the low-temperature gas, a mass accretion rate of approximately 300 solar masses per year, and a characteristic size of 10-20 kpc for the cool gas. The Fe abundance in the core (approximately 0.4) is similar to the Fe abundance averaged over the whole cluster, indicating that Fe emission is not strongly concentrated about NGC 1275. The Si and S abundances are consistent with solar values.

Mushotzky, R. F.↗

The 20 GHz spacecraft FET solid state transmitter

The engineering development of a solid state transmitter amplifier operating in the 20 GHz frequency band using GaAs field effect transistors (FETs) was detailed. The major efforts include GaAs FET device development, single-ended amplifier stage, balanced amplifier stage, cascaded stage and radial combiner designs, and amplifier integration and test. A multistage GaAs FET amplifier capable of 8.2 W CW output over the 17.9 to 19.1 GHz frequency band was developed. The GaAs FET devices developed represent state of the art FET power device technology. Further device improvements are necessary to increase the bandwidth to 2.5 GHz, improve dc-to-RF efficiency, and increase power capability at the device level. Higher power devices will simplify the amplifier combining scheme, reducing the size and weight of the overall amplifier.

Source record↗

High-efficiency solid state power amplifier

A high-efficiency solid state power amplifier (SSPA) for specific use in a spacecraft is provided. The SSPA has a mass of less than 850 g and includes two different X-band power amplifier sections, i.e., a lumped power amplifier with a single 11-W output and a distributed power amplifier with eight 2.75-W outputs. These two amplifier sections provide output power that is scalable from 11 to 15 watts without major design changes. Five different hybrid microcircuits, including high-efficiency Heterostructure Field Effect Transistor (HFET) amplifiers and Monolithic Microwave Integrated Circuit (MMIC) phase shifters have been developed for use within the SSPA. A highly efficient packaging approach enables the integration of a large number of hybrid circuits into the SSPA.

Wallis, Robert E.↗

Solid-State Nuclear Power

A strategy for "Solid-State" Nuclear Power is proposed to guide development of technologies and systems into the second 50 years of nuclear spaceflight. The strategy emphasizes a simple and highly integrated system architecture with few moving parts or fluid loops; the leverage of modern advances in materials, manufacturing, semiconductors, microelectromechanical and nanotechnology devices; and the targeted advancement of high temperature nuclear fuels, materials and static power conversion to enable high performance from simple system topologies.

George, Jeffrey A.↗

Solid-State Spectral Light Source System

A solid-state light source combines an array of light-emitting diodes (LEDs) with advanced electronic control and stabilization over both the spectrum and overall level of the light output. The use of LEDs provides efficient operation over a wide range of wavelengths and power levels, while electronic control permits extremely stable output and dynamic control over the output. In this innovation, LEDs are used instead of incandescent bulbs. Optical feedback and digital control are used to monitor and regulate the output of each LED. Because individual LEDs generate light within narrower ranges of wavelengths than incandescent bulbs, multiple LEDs are combined to provide a broad, continuous spectrum, or to produce light within discrete wavebands that are suitable for specific radiometric sensors.

Maffione, Robert↗

Introduction to the Solid State Based Interior Lighting System for ISS

Solid state lighting assembly (SSLA) were designed to replace general luminaire assembly (GLA) for both general interior illumination and improved circadian rhythm through melatonin control using multiple spectrums. To accomplish these goals, the light is design to operate in 3 modes with 3 distinct spectrum. The different spectrum provide control of the blue portion of the light which impacts melatonin production in humans which impacts sleep. General mode is a 4500K "neutral" light spectrum intended to the be the default mode of operation for day to day operations. Pre-sleep mode is a 2700K "warm" light spectrum intended to be used by the crew at the end of the work day. Phase-shift mode is a 6500K "cool" light spectrum intended to be used for altering the crew's sleep patterns.

Maida, James C.↗

Solid-State Ultracapacitor for Improved Energy Storage

NASA's Marshall Space Flight Center has developed a solid-state ultracapacitor using a novel nanocomposite, dielectric material. The material's design is based on the internal barrier layer capacitance (IBLC) concept, and it uses novel dielectric and metallic conductive ink formulations. Novel processing methods developed by NASA provide for unique dielectric properties at the grain level. Nanoscale raw material powders are tailored using a variety of techniques and then formulated into a special ink. This dielectric ink is used with novel metallic conductive ink to print a capacitor layer structure into any design necessary to meet a range of technical requirements. The innovation is intended to replace current range safety batteries that NASA uses to power the systems that destroy off-course space vehicles. A solid-state design provides the needed robustness and safety for this demanding application.

Nabors, Sammy↗

Design and development of an all-solid-state laser unit for microgravity combustion applications

The laser-induced fluorescence (LIF) technique is a sensitive and noninvasive method for imaging of flames and for monitoring of temperature and the presence of transient molecular species in flames. Our research effort has two major objectives: (1) to use LIF to study the fundamentals of microgravity combustion via spectroscopic characterization of free radicals, and (2) to design and develop an all-solid-state portable laser unit for combustion studies in a microgravity environment. Well-characterized free radicals, namely hydroxyl (OH) and methoxy (CH3O), have analytically convenient bands that can be laser-excited in the 280-298 nm spectral region with the newly discovered solid-state tunable laser, which is based on the LiCaAIF6:Ce3+(LiCAF:Ce) single crystal pumped by the quadrupled (266 nm) output of a Q-switched YAG:Nd laser. The 266 nm YAG radiation (of about 10 mJ pulse energy) was split into two beams of about equal intensity, one used for photolysis of the free radical precursor and the other used for pumping the laser crystal. Tunability of the LiCAF:Ce laser was provided by a step-motor-driven Littrow-mounted diffraction grating. Laser excitation spectra of the CH3O radical was recorded in the 291.5-296.5 nm region with 0.15 cm(exp -1) resolution. Laboratory experiments have thus successfully shown that the idea of using the LiCAF:Ce laser as a dual-purpose photolysis and excitation source can pay rich dividends and that such a laser can be the center piece of an all-solid-state portable device that can be used for routine analytical investigations of microgravity combustion phenomena.

Kamal, Mohammed M.↗

Single Event Upset Effects on the Clementine Solid State Data Recorder

The sensitivity of the Clementine 2.1 Gbit Solid State Data Recorder (SSDR) to single event upsets was characterized in ground tests. Subsequent in-situ measurements of the ambient radiation environment by experiments on-board Clementine permitted evaluation of the ability of models of the single event phenomenon in the SSDR to be tested using actual data. Initial results from the analysis reveal a nearly constant background upset rate of ~71 bit flips/day for the SSDR. There is no obvious correlation with a solar proton event recorded by Clementine and several other spacecraft on 20-21 February 1994, indicating that the SSDR was not sensitive to protons. The constant rate is thus interpreted as being a function of the Galactic Cosmic Ray heavy ion environment. A pronounced lunar orbit altitude dependence has also been identified in the data though the cause has not yet been unambiguously identified.

Clementine↗

Solar Pumped Solid State Lasers for Space Solar Power: Experimental Path

We outline an experimentally based strategy designed to lead to solar pumped solid state laser oscillators useful for space solar power. Our method involves solar pumping a novel solid state gain element specifically designed to provide efficient conversion of sunlight in space to coherent laser light. Kilowatt and higher average power is sought from each gain element. Multiple such modular gain elements can be used to accumulate total average power of interest for power beaming in space, e.g., 100 kilowatts and more. Where desirable the high average power can also be produced as a train of pulses having high peak power (e.g., greater than 10(exp 10 watts). The modular nature of the basic gain element supports an experimental strategy in which the core technology can be validated by experiments on a single gain element. We propose to do this experimental validation both in terrestrial locations and also on a smaller scale in space. We describe a terrestrial experiment that includes diagnostics and the option of locating the laser beam path in vacuum environment. We describe a space based experiment designed to be compatible with the Japanese Experimental Module (JEM) on the International Space Station (ISS). We anticipate the gain elements will be based on low temperature (approx. 100 degrees Kelvin) operation of high thermal conductivity (k approx. 100 W/cm-K) diamond and sapphire (k approx. 4 W/cm-K). The basic gain element will be formed by sequences of thin alternating layers of diamond and Ti:sapphire with special attention given to the material interfaces. We anticipate this strategy will lead to a particularly simple, robust, and easily maintained low mass modelocked multi-element laser oscillator useful for space solar power.

Fork, Richard L.↗

Advanced Solid-State Array Spectrometer (ASAS) data sets from the 1990 field season: A unique look at two forested ecosystems

The Advanced Solid-state Array Spectrometer (ASAS) is a pointable imaging spectrometer which uses a solid-state array to acquire imagery of terrestrial targets in 29 spectral bands from .4 to .8 microns. Performance and calibration of the instrument are described. The ASAS data sets obtained in 1990 provide a unique look at forest canopies from two different forest regions of the North America continent under varying temporal, spectral, and bidirectional conditions. These data sets will be used to study such parameters as the albedo of forest canopies, the dynamics of scene radiation due to factors such as canopy architecture, moisture stress, leaf chemistry, topography, and understory composition.

Walthall, Charles L.↗

Some possible effects of solid-state deformation on the thermal evolution of ice-silicate planetary bodies

Several ways in which solid-state deformation could be important in the evolution of an ice-silicate body are considered. The considerations suggest several scenarios for the evolution of Ganymede and Callisto which might be tested on the basis of Voyager and Galileo results. Several potential sources of heat may have caused extensive melting early in the history of these bodies, including a high initial luminosity of Jupiter, accretional heating, gravitational segregation of ice and silicates in a homogeneously accreted body, and deformation by synchronous rotation. The analysis leads to the conclusion that two mechanisms - diapirism and solid-state convection - could be sufficient to inhibit the development of an excessive liquid water mantle, or to cause refreezing of such a mantle formed prior to steady-state conditions or from other heat sources.

Parmentier, E. M.↗

Advanced solid state sensor system for remote sensing from satellite

Discussion of approaches to providing the needed performance improvement in solid state sensor systems for remote sensing from future resources surveying satellites. An advanced breadboard line array imaging system using long detector arrays from a number of small chips has been built. Test results and typical imagery produced by the breadboard system demonstrate the capabilities of solid state imager technology.

Thompson, L. L.↗

Emerging solid-state laser technology by lidar/DIAL remote sensing

Significant progress has been made in recent years in the development of new, solid-state laser sources. This talk will present an overview of some of the new developments in solid-state lasers, and their application toward lidar/DIAL measurements of the atmosphere. Newly emerging lasers such as Ho:YAG, Tm:YAG, OPO, and Ti:Sapphire will be covered, along with the spectroscopic parameters required for differential operational modes of atmospheric remote sensing including Doppler-Windshear lidar, Tunable laser detection of water/CO2, and broad linewidth OPO's for open path detection of pollutant hydrocarbon gases. Additional considerations of emerging laser technology for lidar/DIAL will also be covered.

Killinger, Dennis↗

Single-mode, All-Solid-State Nd:YAG Laser Pumped UV Converter

In this paper, the status of a high-energy, all solid-state Nd:YAG laser pumped nonlinear optics based UV converter development is discussed. The high-energy UV transmitter technology is being developed for ozone sensing applications from space based platforms using differential lidar technique. The goal is to generate greater than 200 mJ/pulse with 10-50 Hz PRF at wavelengths of 308 nm and 320 nm. A diode-pumped, all-solid-state and single longitudinal mode Nd:YAG laser designed to provide conductively cooled operation at 1064 nm has been built and tested. Currently, this pump laser provides an output pulse energy of >1 J/pulse at 50 Hz PRF and a pulsewidth of 22 ns with an electrical-to-optical system efficiency of greater than 7% and a M(sup 2) value of <2. The single frequency UV converter arrangement basically consists of an IR Optical Parametric Oscillator (OPO) and a Sum Frequency Generator (SFG) setups that are pumped by 532 nm wavelength obtained via Second Harmonic Generation (SHG). In this paper, the operation of an inter cavity SFG with CW laser seeding scheme generating 320 nm wavelength is presented. Efforts are underway to improve conversion efficiency of this mJ class UV converter by modifying the spatial beam profile of the pump laser.

Prasad, Narasimha S.↗