Forum. Question 3 - Relevance of laboratory experiments to actual radiating flows
Base heating model test facilities, and methods of obtaining design numbers for full scale plume radiation
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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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Study to investigate the effects of ionizing radiation on transistor surfaces First quarterly report, 1 Jul. - 30 Sep. 1965
Ionizing radiation effects on transistor surfaces - facilities, fixtures, and instrumentation checked out for X-ray tests of transistors
TEST FACILITY↗
Interaction of graphite and ablative materials with CO2-laser, carbon-arc, and xenon-arc radiation
The behavior of graphite and several charring ablators in a variety of high radiative heat flux environments was studied in various radiative environments produced by a CO2 laser and a carbon arc facility. Graphite was also tested in xenon arc radiation. Tests were conducted in air nitrogen, helium, and a mixture of CO2 and nitrogen, simulating the Venus atmosphere. The experimental results are compared with theoretical results obtained with a one dimensional charring ablator analysis and a two dimensional subliming ablator analysis. Photomicroscopy showed no significant differences in appearance or microstructure of the charring ablators or graphite after testing in the three different facilities, indicating that the materials respond fundamentally the same to the radiation of different frequencies. The performance of phenolic nylon and graphite was satisfactorily predicted with existing analyses and published material property data.
Brewer, W. D.↗
Total Ionizing Dose Testing of the Analog Devices’ AD648 Dual Precision Operational Amplifier
The Analog Devices (ADI) AD648 was tested for total ionizing dose response at the Goddard Space Flight Center (GSFC) Radiation Effects Facility (REF) beginning 1 June 2011. This test served as the radiation lot acceptance test (RLAT) for the lot date code (LDC) tested. Low dose rate (LDR) irradiations were performed in this test so that the device susceptibility to enhanced low dose rate sensitivity (ELDRS) could be determined.
Alvin J Boutte↗
The multidisciplinary grant as a mechanism for support of basic research in universities
Space science research at University of California at Los Angeles - magnetic shielded test facility, plasma studies, chemical effects of ionizing uv radiation, and 24 inch telescope
IONIZING RADIATION↗
Bringing Single-Event Effects Down to Earth
In the 47 years since single-event effects were first observed in spacecraft electronics, radiation experts have developed an effective methodology supported by a nationwide infrastructure. A highly skilled workforce of radiation engineers has developed test facilities and methods, modeling and simulation techniques, and mitigation and design strategies to ensure space missions meet their performance and reliability requirements even in the harsh radiation environments of space. Now, increasing performance demands of space missions, the continued disruptive evolution of microcircuit technologies and growth and changes of the space industry have combined with an aging infrastructure are placing increasing strain on the radiation effects community, and the community is responding.
Single-event effects↗
Radiation Transport and Shielding Challenges at NASA Marshall Space Flight Center
Several unique radiation transport and shielding challenges for various spacecraft and ground test facilities have recently been explored at NASA Marshall Space Flight Center (MSFC). Many radiation transport methods and code packages have been utilized during this effort, and some additional analytical tools have been developed to support this work. This includes the development of a nuclear thermal propulsion stage, in which radiation damage to hardware, radiation heating, and crew dose must be assessed for a large spacecraft. Radiation shielding for such a stage must be optimized to minimize weight, and additional dose consequences are expected from cosmic sources. Development of a nuclear engine requires ground test facilities, which themselves require significant development effort that includes deep-penetration shielding analysis for facility design and site selection. Additional radiation transport analysis has been performed in support of a notional lander mission to Europa, the icy moon of Jupiter. The radiation burden to spacecraft has been analyzed, and charged particle radiation transport methods have been utilized to apply correct doses to material samples in ground test facilities.
Caffrey, Jarvis A.↗
In-Situ Testing Methods for Mixed-Mode Harsh Environments
Future NASA missions are driving a need for instrumentation and space electronics that will operate at extreme temperatures, with low mass and extended deployments. This need results in devices that will experience dose damage at both low and high temperatures that will suppress annealing and induce accelerated wear out issues. Therefore, the ability to perform radiation tests on devices at temperature is critical. This paper analyses the methods and process to enable these test as developed at the JPL Dynamitron Facility. Since electronics are the radiation source for this facility, the steps to ensure parity with cobalt-60 testing are discussed. Also discussed are the implications for system level testing and mixed radiation mode testing for highly integrated and scaled devices.
Scheick, Leif Z↗
Investigation of advanced propulsion technologies: The RAM accelerator and the flowing gas radiation heater
The two principal areas of advanced propulsion investigated are the ram accelerator and the flowing gas radiation heater. The concept of the ram accelerator is presented as a hypervelocity launcher for large-scale aeroballistic range applications in hypersonics and aerothermodynamics research. The ram accelerator is an in-bore ramjet device in which a projectile shaped like the centerbody of a supersonic ramjet is propelled in a stationary tube filled with a tailored combustible gas mixture. Combustion on and behind the projectile generates thrust which accelerates it to very high velocities. The acceleration can be tailored for the 'soft launch' of instrumented models. The distinctive reacting flow phenomena that have been observed in the ram accelerator are relevant to the aerothermodynamic processes in airbreathing hypersonic propulsion systems and are useful for validating sophisticated CFD codes. The recently demonstrated scalability of the device and the ability to control the rate of acceleration offer unique opportunities for the use of the ram accelerator as a large-scale hypersonic ground test facility. The flowing gas radiation receiver is a novel concept for using solar energy to heat a working fluid for space power or propulsion. Focused solar radiation is absorbed directly in a working gas, rather than by heat transfer through a solid surface. Previous theoretical analysis had demonstrated that radiation trapping reduces energy loss compared to that of blackbody receivers, and enables higher efficiencies and higher peak temperatures. An experiment was carried out to measure the temperature profile of an infrared-active gas and demonstrate the effect of radiation trapping. The success of this effort validates analytical models of heat transfer in this receiver, and confirms the potential of this approach for achieving high efficiency space power and propulsion.
Bruckner, A. P.↗
Hot cell radiation testing and inspection
Hot cell complex inspection and testing to assure radiation shielding requirements
RADIATION SHIELDING↗
New Technologies Advancing Thermophysics
Researchers at NASA Ames in California have built a new facility that uses multiple 50-kW continuous wave lasers to add the capability for simulating radiative heating on thermal protection materials. The new facility, the Laser Enhanced Arc-jet Facility (LEAF-Lite), was added to NASA Ames’s Interaction Heating Facility arc-jet and now allows for test articles to be heated by both convective and radiative heat flux, making the facility more like flight. Using this new system, researchers can now simulate radiant heating with the laser and convective heating with the arc-jet simultaneously on a single test article. During its initial test in October 2017, the lasers radiatively heated a 6” x 6” Avcoat wedge sample to 405 W/sq.cm while the arc-jet simultaneously provided 160 W/sq.cm of convective heat, resulting in a total heat flux of 565 W/sq.cm. Radiative heating is more prevalent in missions with higher atmospheric entry speeds like the Orion space capsule or interplanetary scientific probes. Later this year, scientists will expand the spot size to cover 17” x 17” to test an Orion TPS panel.
Brandis, Aaron↗
Space Radiation Shielding Studies for Astronaut and Electronic Component Risk Assessment
The dosimetry component of the Center for Radiation Engineering and Science for Space Exploration (CRESSE) will design, develop and characterize the response of a suite of radiation detectors and supporting instrumentation and electronics with three primary goals that will: (1) Use established space radiation detection systems to characterize the primary and secondary radiation fields existing in the experimental test-bed zones during exposures at particle accelerator facilities. (2) Characterize the responses of newly developed space radiation detection systems in the experimental test-bed zones during exposures at particle accelerator facilities, and (3) Provide CRESSE collaborators with detailed dosimetry information in experimental test-bed zones.
Fuchs, Jordan Robert↗
Deep Space Test Bed for Radiation Studies
The Deep Space Test-Bed (DSTB) Facility is designed to investigate the effects of galactic cosmic rays on crews and systems during missions to the Moon or Mars. To gain access to the interplanetary ionizing radiation environment the DSTB uses high-altitude polar balloon flights. The DSTB provides a platform for measurements to validate the radiation transport codes that are used by NASA to calculate the radiation environment within crewed space systems. It is also designed to support other Exploration related investigations such as measuring the shielding effectiveness of candidate spacecraft and habitat materials, testing new radiation monitoring instrumentation and flight avionics and investigating the biological effects of deep space radiation. We describe the work completed thus far in the development of the DSTB and its current status.
Adams, James H.↗
Development of a radiation-hard photomultiplier tube
In a radiation-hard photomultiplier tube (PMT) such as has been developed for stabilization of the Galileo spacecraft as it goes through the Jovian high energy radiation belts, the primary effects of high energy electron and proton radiation that must be resisted are the production of fluorescence and Cerenkov emission. The present PMT envelope is ceramic rather than glass, and employs a special, electron-focusing design which will collect, accelerate and amplify electrons only from desired photocathode areas. Tests in a Co-60 radiation facility have shown that the radiation-hard PMT produces less than 2.5 percent of the radiation noise of a standard PMT.
Birnbaum, M. M.↗
Analytic Methods for Predicting Significant Multi-Quanta Effects in Collisional Molecular Energy Transfer
Collision-induced transitions can significantly affect molecular vibrational-rotational populations and energy transfer in atmospheres and gaseous systems. This, in turn. can strongly influence convective heat transfer through dissociation and recombination of diatomics. and radiative heat transfer due to strong vibrational coupling. It is necessary to know state-to-state rates to predict engine performance and aerothermodynamic behavior of hypersonic flows, to analyze diagnostic radiative data obtained from experimental test facilities, and to design heat shields and other thermal protective systems. Furthermore, transfer rates between vibrational and translational modes can strongly influence energy flow in various 'disturbed' environments, particularly where the vibrational and translational temperatures are not equilibrated.
Bieniek, Ronald J.↗
Solar radiation calibration facility.
A recently completed calibration facility for the NASA Mississippi Test Site is described. It combines the spectrum of water cooled long arc xenon radiation sources with the integration sphere concept covered by a special barium sulfate diffusely reflecting paint. The sphere is six feet in diameter and completely encompasses the four xenon sources (2.5 kW each) and the five pyranometers under calibration. The sources are contained within the base of the central pedestal and allow the radiation to be emitted into the lower hemisphere. Only through diffuse reflection and multiple scattering is the radiation finally incident upon the test zone, which is in the equatorial plane of the sphere on the top of the pedestal. The sphere is temperature controlled.
Hershey, T. L.↗
Backshell Radiation Measurements in the EAST Facility for Titan Entry
A new test series was performed in the Electric Arc Shock Tube (EAST) facility, with the aim of reproducing conditions which will be encountered in the backshell of the Dragonfly spacecraft. Measurements of shock-layer radiation from CN Violet, CN Red and C 2 Swan bands are made in mixtures of 2.2% CH 4 in N 2 (by mole) heated by incident shock waves spanning from 3 to 7 km/s. This study focuses on the spectrally and spatially resolved measurement of absolute radiance made with four optical emission spectrometers spanning 220-1400 nm. Comparison with CFD simulations and equilibrium conditions were made. The predicted radiation was found to be between -40% to 100% from the measurements for the nonequilibrium peak radiance, increasing with velocity. At 7 cm/150 μs from the shock front, the discrepancies appear to be larger, ranging from -50 to 200%. Comparison between measured and predicted temperatures and number densities of CN indicate shortcomings in the non-Boltzmann model of CN.
Augustin Tibere-Inglesse↗
Backshell Radiation Measurements in the EAST Facility for Titan Entry
A new test series was performed in the Electric Arc Shock Tube (EAST) facility, with the aim of reproducing conditions which will be encountered in the backshell of the Dragonfly spacecraft. Measurements of shock-layer radiation from CN Violet, CN Red and C 2 Swan bands are made in mixtures of 2.2% CH 4 in N 2 (by mole) heated by incident shock waves spanning from 3 to 7 km/s. This study focuses on the spectrally and spatially resolved measurement of absolute radiance made with four optical emission spectrometers spanning 220-1400 nm. Comparison with CFD simulations and equilibrium conditions were made. The predicted radiation was found to be between -40% to 100% from the measurements for the nonequilibrium peak radiance, increasing with velocity. At 7 cm/150 μs from the shock front, the discrepancies appear to be larger, ranging from -50 to 200%. Comparison between measured and predicted temperatures and number densities of CN indicate shortcomings in the non-Boltzmann model of CN.
Augustin Tibere-Inglesse↗