Stellar photometric data for six different photocathode materials and the silicon detector.
Photodetector responses to radiant energy from many stars tabulated for various photocathode materials and silicon detector
Forbes, F. F.↗
SEARCH · Engineering Papers
Results for “RADIANT ENERGY”
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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Directional control of radiant heat
Surface with grooves having flat bases gives directional emissivities and absorptivities that can be made to approximate a perfect directional surface. Radiant energy can then be transferred in desired directions.
Howell, J. R.↗
Opacified fibrous thermal insulation
Lightweight, opacified, glass fiber batting for high temperature insulation in cryogenic tanks has lower apparent thermal conductivity than untreated insulations. Decrease results from impeding the transmission of radiant energy without increasing the solid conductance of the material.
Chambellan, R. E.↗
Temperature measurements of air plasmas in the reflected shock region
Air plasmas temperature measurements behind reflected shock wave, examining radiative cooling effects and total radiant energy
Wilson, K. H.↗
Interstellar grain temperatures - Effects of grain materials and radiation fields
Interstellar grain temperatures, considering radiant energy distribution and optical properties effects
Greenberg, J. M.↗
High solar intensity radiometer
Silicon solar cells are used to measure visible radiant energy and radiation intensities to 20 solar constants. Future investigations are planned for up to 100 solar constants. Radiometer is small, rugged, accurate and inexpensive.
Jack, J. R.↗
Experimental investigation to simulate propellant heating in the nuclear light bulb engine.
Experiments to heat a simulated propellant to high bulk temperatures by the absorption of thermal radiation are discussed. Argon seeded with micron-sized carbon particles was used as the simulated propellant; a 500 kw d-c arc was used as the radiant energy source. Bulk temperatures up to 3860 K were obtained with greater than 95% of the incident radiation absorbed. The arc radiation source, seed dispersal equipment, techniques used to prevent transparent wall coating by the seeds, and calorimetric measurement of bulk temperature are also discussed.
Klein, J. F.↗
Nuclear light bulb propellant heating simulation using a tungsten/argon aerosol and radiation from a dc arc surrounded by a segmented mirror cavity
Experiments were conducted to simulate radiant heating of the propellant stream of a nuclear light bulb engine to obtain high bulk exit temperatures in the flowing simulated propellant stream by absorption of large fractions of the incident thermal radiation. A high-power, vortex-stabilized dc arc within an uncooled fused silica tube was used as the radiant energy source. It was surrounded by a mirror system to increase the radiation incident on the simulated propellant. The 12.7-cm-long by 2.3-cm-wide, diverging-duct test section had a transparent front wall and a reflecting rear wall. The central stream of seeded gas, a tungsten-particle/argon aerosol, had unseeded argon buffer layers on both sides to prevent coating of the duct walls. Arc operating times were approximately 0.5 sec with power levels up to 780 kW. Bulk exit temperatures were measured using a calorimeter downstream of the duct. The maximum simulated propellant bulk exit temperature obtained was 4515 K, compared with 3860 K in previous tests, 3300 to 3700 K expected in in-reactor tests in the Nuclear Furnace, and 6660 K in the reference nuclear light bulb engine. The maximum temperature in these tests was limited primarily by the amount of radiation incident on the test section (determined by the arc operating characteristics and the effectiveness of the mirror cavity).
Klein, J. F.↗
Investigation of gaseous nuclear rocket technology
The experimental and theoretical investigations conducted during the period from September 1969 through September 1972 are reported which were directed toward obtaining information necessary to determine the feasibility of the full-scale nuclear light bulb engine, and of small-scale nuclear tests involving fissioning uranium plasmas in a unit cell installed in a driver reactor, such as the Nuclear Furnace. Emphasis was placed on development of RF simulations of conditions expected in nuclear tests in the Nuclear Furnace. The work included investigations of the following: (1) the fluid mechanics and containment characteristics of one-component and two-component vortex flows, both unheated and RF-induction heated; (2) heating of particle-seeded streams by thermal radiation from a dc arc to simulate propellant heating; (3) condensation and separation phenomena for metal-vapor/heated-gas mixtures to provide information for conceptual designs of components of fuel exhaust and recycle systems; (4) the characteristics of the radiant energy spectrum emitted from the fuel region, with emphasis on definition of fuel and buffer-gas region seed systems to reduce the ultraviolet radiation emitted from the nuclear fuel; and (5) the effects of nuclear radiation on the optical transmission characteristics of transparent materials.
Kendall, J. S.↗
High temperature insulation materials for reradiative thermal protection systems
Results are presented of a two year program to evaluate packaged thermal insulations for use under a metallic radiative TPS of a shuttle orbiter vehicle. Evaluations demonstrated their survival for up to 100 mission reuse cycles under shuttle acoustic and thermal loads with peak temperatures of 1000 F, 1800 F, 2000 F, 2200 F and 2500 F. The specimens were composed of low density refractory fiber felts, packaged in thin gage metal foils. In addition, studies were conducted on the venting requirements of the packages, salt spray resistance of the metal foils, and the thermal conductivity of many of the insulations as a function of temperature and ambient air pressure. Data is also presented on the radiant energy transport through insulations, and back-scattering coefficients were experimentally determined as a function of source temperature.
Hughes, T. A.↗
Inventory of forest and rangeland and detection of forest stress
The author has identified the following significant results. At the Atlanta site (226B) it was found that bulk color composites for October 15, 1972, and April 13, 1973, can be interpreted together to disclose the location of the perennial Kudzu vine (Pyeraria lobata). Land managers concerned with Kudzu eradication could use ERTS-1 to inventory locations over 200 meters (660 feet) square. Microdensitometer data collected on ERTS-1 Bulk photographic products for the Manitou test site (226C) have shown that the 15-step gray-scale tablets are not of systematic equal values corresponding to 1/14 the maximum radiant energy incident on the MSS sensor. The gray-scale values present a third-order polynomial function rather than a direct linear relationship. Although data collected on step tablets for precision photographic products appear more discrete, the density variation within blocks in almost as great as variations between blocks. These system errors will cause problems when attempting to analyze radiometric variances among vegetation and land use classes.
Heller, R. C.↗
Volume-reflecting dielectric heat shield
White, volume-reflecting dielectric material absorbs essentially none of the incident radiant energy, and continues to reflect even though in severe environment its surface is melted and is being vaporized. Process of overall reflectance in dielectric material, involving internal refractions and reflections, is similar to process of reflection in paints.
Nachtsheim, P. R.↗
Improved nondispersive infrared analyzer
Light from radiant energy source passes through filter, sample, and reference gas chambers to detector. Chamber with amount of gas to be measured is sealed. Filter may be gelatinous, interference, dispersive, or negative-gas, as required.
Dimeff, J.↗
Apparatus for controlling the temperature of balloon-borne equipment
A novel apparatus for controlling the temperature of balloon-borne equipment is disclosed, the apparatus serving to utilize the radiant energy emitted by the earth and its atmosphere so as to control the temperature of equipment. The apparatus comprises a housing to be carried aloft by a balloon and defining an enclosure for an instrumentation package. The enclosure includes an upper shield portion as well as a bottom window portion at the base, the bottom window facing the earth below during flight. The upper shield portion is constructed of a material such as aluminized Mylar, which serves to reflect direct sunlight.
Schach, M.↗
Photoionization branching ratios and vibrational intensity distribution for N2, CO; and CO2 between 53 and 75 nm
The probability of radiation producing ions in specific electronic and vibrational levels was documented. For example, when a narrow band-pass of solar ionizing photons is incident on an atmospheric species it is now possible to describe, accurately, how the radiant energy is shared among the various electronic states of the ions produced. The molecules studied were N2, CO, and CO2. These molecules were photoionized by radiation between 53 and 75 nm. The effects of autoionization are discussed and continuum vibrational intensities are tabulated and compared with theoretical Franck-Condon factors where available. The branching ratios and partial cross sections for ionization into various electronic states are tabulated.
Samson, J. A. R.↗
Instruments for measuring radiant thermal fluxes
An absolute two-sided radiometer, designed on the principle of replacing absorbed radiant energy with electrical energy, is described. The sensitive element of the detector is a thermoelectric transducer of thermal flux. The fabrication technology, methods of measurement, technical characteristics, and general operation of the instrument are presented.
Gerashenko, O. A.↗
Solar flux and its variations
Current knowledge of the electromagnetic solar spectrum and radiant energy output for conditions of quiet and active sun is summarized. Discussed are temporal behavior and occurrence of solar phenomena such as active regions, calcium plages and flares, X-rays, UV and other energetic emissions, and their relationships to 11- and 22-year solar cycles.
Smith, E. V. P.↗
Automatic solar tracker
Mechanism uses differential pressure of condensable fluid against fixed piston to equalize radiant energy on pair of blackbody elements.
Conroy, B. L.↗