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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS1981

Power requirements for space crystal growth

The need for power to grow silicon of a size suitable to make into devices is addressed. The expected results are tied to available power. The projection of the size of float zone crystals as a function of time is discussed. An accompanying graph shows that 4 in. will be the normally used diameter by 1985 and 5 in. by 1990. Material to be tested in device lines in this time frame should be 4 in. or more. The various power losses, 25 kW with a 50% power efficiency, which is much improved over present RF heating efficiencies.

Kern, E. L.↗
DOE OSTI2016

Capabilities development for transient testing of advanced nuclear fuels at TREAT

The TREAT facility is a unique capability at the Idaho National Laboratory currently being prepared for resumption of nuclear transient testing. TREAT is an air-cooled reactor where the driver core is made up of urania dispersed in graphite blocks and encapsulated in zirconium alloy cans. In addition to the reactor itself, the foundation for TREAT's capabilities will also include a suite of irradiation vehicles and supporting infrastructure to provide the desired specimen boundary conditions while supporting a variety of instrumentation needs. Although TREAT historically supported all kinds of nuclear fuels, including LWR's, SFR's, space nuclear propulsion, research reactor plate-type fuels, and even fuels for use in the driver core of other transient test reactors, the majority of TREAT's more-recent experiment programs revolved around SFR's and sodium-environment test capsules and loops. MK-series loop experiment-specific test trains could be outfitted with a variety of instruments to monitor test and specimen conditions while the fast neutron hodoscope collected information about fuel movement before, during, and after transient excursions. The SERTTA (Static Environment Rodlet Transient Test Apparatuses) devices will be general purpose vehicles capable of providing inert gas, water (up to PWR conditions), steam, or perhaps even molten sodium environments within vessel-like capsules. The Multi-SERTTA vehicle design is particularly novel as it makes use of the full active core length in TREAT to test four small rodlets (∼12 cm length), each within its own hermetic boundary, it will be capable of housing pre-irradiated fuel specimens. Additional modules and adaptations of Multi-SERTTA will enable rapid loop pressure blowdown to simulate LOCA conditions. The Super-SERTTA, akin to the Multi-SERTTA will offer more possibilities for simulating transient phenomena.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2015

WE-D-BRA-03: Four-Dimensional Dose Reconstruction Through Retrospective Phase Determination Using Cine Images of Electronic Portal Imaging Device

Purpose: To test a method to reconstruct a four-dimensional (4D) dose distribution using the correlation of pre-calculated 4D electronic portal imaging device (EPID) images and measured cine-EPID images. Methods: 1. A phantom designed to simulate a tumor in lung (a polystyrene block with 3.0 cm diameter embedded in cork) was placed on a sinusoidally moving platform with 2 cm amplitude and 4 sec/cycle. Ten-phase 4D CT images were acquired for treatment planning and dose reconstruction. A 6MV photon beam was irradiated on the phantom with static (field size=5×8.5 cm{sup 2}) and dynamic fields (sliding windows, 10×10 cm{sup 2}, X1 MLC closing in parallel with the tumor movement). 2. 4D and 3D doses were calculated forwardly on PTV (1 cm margin). 3. Dose images on EPID under the fields were calculated for 10 phases. 4. Cine EPID images were acquired during irradiation. 5. Their acquisition times were correlated to the phases of the phantom at which irradiation occurred by inter-comparing calculated “reference” EPID images with measured images (2D gamma comparison). For the dynamic beam, the tumor was hidden under MLCs during a portion of irradiation time; the correlation performed when the tumor was visible was extrapolated. 6. Dose for each phase was reconstructed on the 4D CT images and summed over all phases. The summation was compared with forwardly calculated 4D and 3D dose distributions. Monte Carlo methods were used for all calculations. Results: For the open and dynamic beams, the 4D reconstructed doses showed the pass rates of 92.7 % and 100 %, respectively, at the isocenter plane given 3% / 3 mm criteria. The better agreement of the dynamic beam was from its dose gradient which blurred the otherwise sharp difference between forward and reconstructed doses. This also contributed slightly better agreement in DVH of PTV. Conclusion: The feasibility of 4D reconstruction was demonstrated.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2012

A Novel Carotid Device for Embolic Diversion: Lessons Learned from a 'First in Man' Trial in Patients with Atrial Fibrillation

Purpose: This study was designed to investigate a novel device that was developed to direct emboli away from the internal carotid artery to the external carotid artery to prevent embolic stroke while avoiding the necessity for anticoagulation with warfarin. Methods: A stent-like, self-expandable filter was developed consisting of fine cobalt alloy mesh. After promising preclinical animal testing, the device was implanted into the common carotid artery extending into the external carotid artery in three patients with atrial fibrillation, each of whom were at high-risk for cerebral emboli and were suboptimal candidates for anticoagulation. Follow-up was performed clinically and with carotid duplex ultrasound. Results: The implantation was successful in all three patients. Unrestricted flow through the filter was demonstrated in each patient at 6 months by duplex sonography. However, at 7 months ultrasound demonstrated occlusion of the internal carotid artery filter in one patient, which was subsequently confirmed by angiography. Subtotal filter occlusion occurred in a second patient at 14 months. Neither patient had clinical symptoms. Both internal carotid arteries were successfully recanalized using standard angioplasty techniques without complication. The third patient had completely normal carotid blood flow at 29 months follow-up. Conclusions: Implantation of a novel device intended to divert emboli away from the internal carotid artery was feasible, but resulted in occlusive neointimal proliferation in two of three patients. These results demonstrate a discrepancy from the findings of preclinical animal studies and human investigation.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

A nano-structured ZnO film as diagnostic X-ray sensor

Currently some international organizations such as WHO and IAEA have shown concerns about the quality of diagnostic services in clinics and hospitals that use ionizing radiation. In fact, the IAEA recommend that the characteristics of the X-ray beam must be adjusted to obtain the highest quality of the radiographic image with the minimum exposure to the patient. Several types of detectors may be used for monitoring X-ray beams, such as: ionization chamber, photodiode, phototransistor, among others. Recently nano-structured films made of various types of metal oxide materials have been used for various technological applications. Accordingly, the purpose of this paper is to present a sort of device based on a nano-structured zinc oxide (ZnO) to operate as a diagnostic X-ray sensor. By depositing a thin film on the glass substrate some ZnO semiconductor samples were built by sputtering techniques and then mounted in a BNC type connector to perform the electrical characterization. To test the device, we choose a standard X-Ray beam, the RQR9 radiation quality, which is normally used as the tool and condition for calibrating diagnostic X-Ray instruments in the energy range of computed tomography, in accordance with the stated requirements of IEC 61267. A 6430 sub-femto-ammeter, Keithley, was used as electrometer to perform the output readings and simultaneously bias the ZnO sensor. Analysis of the angular dependence and the dose rate were performed to evaluate how the device responds under the RQR9 radiation spectra. Although the results have shown that the ZnO film presents a certain angular dependence, if an angle of incidence of photons is selected, the device displays reproducibility as X-ray sensor and has the feature of radiation hardness unlike other types of semiconductor electronic devices typically used as an X-ray detector. (authors)

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2024

A Simplified Method for Predicting Shaker Voltage in IMMATs

Impedance Matched Multi-Axis Tests (IMMATs) can replicate in-service vibration induced stress more accurately than single axis shaker table tests as they can better match a part’s operational boundary conditions and excite it in multiple degrees of freedom simultaneously. Here, the shakers used in IMMATs are less powerful than shaker tables, so shaker force limits can be exceeded during tests if they are not placed adequately for the desired environment. The ability to predict shaker voltage and force before performing a test is, therefore, helpful in selecting shaker locations so that their limits are not exceeded. In this study, electrodynamic shakers were modeled as discrete electromechanical systems, and the shaker parameters were chosen to match experimentally obtained acceleration/voltage frequency response functions (FRFs). These models were coupled to a finite element model of the device under test (DUT) via dynamic substructuring, and the substructured model was demonstrated to accurately predict shaker voltage as well as the error in reproducing the environment at multiple accelerometer locations. A simple method called the FRF Multiplication method, in which the FRF of the substructured system is approximated as the product of two separate FRFs of the shaker and DUT respectively, was proposed and applied to the same system, yielding similar voltage and error predictions to those obtained using substructuring. Simple case studies were presented to explore the applicability of the proposed method, and it was demonstrated to have similar accuracy to the substructuring method in a range of cases. Additionally, we showed that while it was not possible to derive a unique model of the shakers from acceleration/voltage FRFs alone, the models that could be obtained were sufficient to predict test error almost perfectly and shaker voltage with less than 40 percent error.

42 ENGINEERING↗
NASA NTRS1978

Fabrication and test of digital output interface devices for gas turbine electronic controls

A program was conducted to develop an innovative digital output interface device, a digital effector with optical feedback of the fuel metering valve position, for future electronic controls for gas turbine engines. A digital effector (on-off solenoids driven directly by on-off signals from a digital electronic controller) with optical position feedback was fabricated, coupled with the fuel metering valve, and tested under simulated engine operating conditions. The testing indicated that a digital effector with optical position feedback is a suitable candidate, with proper development for future digital electronic gas turbine controls. The testing also identified several problem areas which would have to be overcome in a final production configuration.

Newirth, D. M.↗
NASA NTRS1984

Ground vibration test of F-16 airplane with initial decoupler pylon

A ground vibration test was conducted on an F-16 airplane loaded on each wing with a 370-gal tank mounted on a standard pylon, a GBU-8 store mounted on a decoupler pylon, and an AIM-9J missile mounted on a wing-tip launcher. The decoupler pylon is a passive wing/store flutter-suppression device. The test was conducted prior to initial flight tests to determine the modal frequencies, mode shapes, and structural damping coefficients. The data presented include frequency response plots, force effect plots, and limited mode shape data.

Cazier, F. W., Jr.↗
NASA NTRS1982

Single event upset sensitivity of low power Schottky devices

Data taken from tests involving heavy ions in the Berkeley 88 in. cyclotron being directed at low power Schottky barrier devices are reported. The tests also included trials in the Harvard cyclotron with 130 MeV protons, and at the U.C. Davis cyclotron using 56 MeV protons. The experiments were performed to study the single event upsets in MSI logic devices containing flip-flops. Results are presented of single-event upsets (SEU) causing functional degradation observed in post-exposure tests of six different devices. The effectiveness of the particles in producing SEUs in logic device functioning was found to be directly proportional to the proton energy. Shielding was determined to offer negligible protection from the particle bombardment. The results are considered significant for the design and fabrication of LS devices for space applications.

Price, W. E.↗
NASA NTRS2009

Irradiation with molecular hydrogen as an accelerated total dose hardness assurance test method for bipolar linear circuits

High dose rate irradiation with hydrogen stress is proposed as an accelerated total dose test method for bipolar linear circuits. The method is validated across process and circuit technologies with five parts that are commonly used in space: a comparator (LM193 from National Semi-conductor), a voltage regulator (HSYE-117 RH from Intersil), a voltage reference (LT1019 from Linear Technology), a JFET input op amp (OP42 from Analog Devices) and a temperature transducer (AD590 from Analog Devices). The testing technique could rapidly establish an upper bound to the low dose rate response of parts in space and help with the part selection process in the design phase of a mission. The technology dependence and the viability of this technique are qualitatively explored using a physical model describing the dose rate response and the effect of hydrogen in bipolar technologies. The model uses four core processes: 1) space charge effects, 2) free electron/hole pair recombination, hole-hydrogen defect reactions in the oxides and 4) proton depassivation of dangling bonds at the Si/SiO2 interface. Radiation hardness assurance implications are discussed.

Pease, Ron↗
DOE OSTI2025

Real-Time Testbed for Smart Grid Recloser Controller

The growing need for a low voltage recloser has become apparent due to the rise in requirements for a smart grid. This includes more detailed management of power flow forward (towards load) and backward (towards generation), source synchronization in real time, more indepth fault responses, and the use of green energy. The SEL-651R-2 relay is a device that can manage these needs, especially in fault response and synchronization, and is commonly used in systems called microgrids. Microgrids are distribution level systems that are able to operate separated from the main grid, are typically installed much closer to the load(s), and are fed by distributed energy resources (DERs), such as wind, solar or diesel generators. The SEL-651R-2 is normally used in the field with presets operative settings, but the Western Michigan University (WMU) Center for Interdisciplinary Research on Secure, Efficient and Sustainable Energy Technology (WMU InterEnergy Center) wished to test this device in its range of capabilities for microgrid application. A Hardware-In-the-Loop (HIL) testbed was implemented and used through the Real Time Digital Simulator (RTDS) using the RSCAD software to test the SEL-651R-2's use cases and functions. The testbed includes a microgrid with interconnection to a larger main grid, and the relay is meant to control the recloser at the point of common coupling (PCC) between the main grid and microgrid. The testbed shows how basic protections, reclosing, and synchronization checks function when handling faults that affect both the microgrid and the main grid.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2023

Commissioning of SRF Cavity Analyzer System

Research and development in Superconducting Radio Frequency (SRF) cavities manufacturing, surface treatment, preparation, and doping techniques for the improvement of cavities performance necessitate reliable cavities’ intrinsic quality factor measurement with accurate and repeatable results. Fermilab Vertical Test Stand facility (VTS) performs ~270 cavities tests per year, including R&D cavities as well as production cavities at each step of their preparation for the placement in accelerator’s cryomodules. Current Fermilab VTS testing system is based on the scalar approach of power measurement, which neglects potential error factors of the RF networks with distributed parameters, hence the assessed measurement errors of such a system might be slightly underestimated. Alternative approach, utilizing a vector measurement (amplitude and phase) of RF signals in the setup with a cavity as a device under test, promises an enhanced accuracy and results traceability. New cavity an alyser system based on this approach (Vector VTS) was developed by D. Frolov et al. and currently undergoes a commissioning process. Basic underlying principles of the system will be presented with the methods of quality factor extraction from S-parameters measurement of multiport cavities and brief error analysis will be discussed. The system architecture will be shown with main components parameters and ensuing testing capabilities. Multiple tests results will be discussed with a cross-check comparison of the results obtained with a conventional testing method. System advantages such as automated calibration process and additional features as a built- in microphonics measurement capability will be presented.

Netepenko, A.↗
NASA NTRS2004

Fabrication of MEMS-Based Microshutter Arrays for Optical Transmission Selection

A MEMS-based programmable aperture mask is under development at the NASA Goddard Space Flight Center. Termed the Microshutter (u-shutter) Array, the device will be used to control the transmission of light, with both high efficiency and contrast, to a multi-object spectrometer on the James Webb Space Telescope. Fabrication of the p-shutter array employs several novel designs and processing techniques. The current generation of micro-shutters consists of 128x64 pixel arrays with unit cell dimensions of 100x200 microns. Shutters are patterned in silicon nitride and sit on a 100 micron silicon frame that is DRIE etched below each shutter. The front and back sides of the device are shown. A magnetic cobalt-iron alloy patterned on top of the shutter allows it to be actuated 90 degrees out-of-plane, into the frame, by an external magnetic field. An electrode on the shutter and a vertical electrode on the sidewall of the frame, approximately 90pm deep, allow them to be electrostatically latched in their rotated position. The vertical electrode is deposited and patterned on the backside of the frame in a single step using a directionally controlled evaporation. Individual addressing of shutters for electrostatic latching is accomplished via a crosspoint addressing scheme, with no on-chip active components. A portion of an array with shutters in the open, latched, and closed positions is shown. Light loss at shutter edges is minimized by an overhanging aluminum light-shield that is anchored to the frame. A photoresist sacrificial layer is used to raise the light-shield up and over the 2 micron gap that surrounds each pixel. After completion, arrays are subjected to life cycle, environmental and optical testing. Fabricated devices have survived 10(exp 6) actuation cycles at both room and cryogenic temperatures and a 14g rms launch-simulation test. Optical testing has shown contrast measurements between open and closed shutters up to 10000:1.

Lynch, Bernard A.↗
NASA NTRS1987

Service-Life Extension of Explosive Escape Devices

Chemical and functional tests yield conservative service-life estimates. Approach to extension of service lives of explosive devices in aircraft escape system developed, supported by testing of representative candidate devices to evaluate quantitatively effects of service, age, and degradation, and to enable responsible, conservative service-life determinations. Five types of explosive components evaluated: rigid and flexible explosive transfer lines; one-way transfers; flexible, linear-shaped charges; and initiation-handles. Extension of service in realistic manner provides both cost savings and increased system reliability.

Bement, L. J.↗
NASA NTRS2012

Pattern Generator for Bench Test of Digital Boards

All efforts to develop electronic equipment reach a stage where they need a board test station for each board. The SMAP digital system consists of three board types that interact with each other using interfaces with critical timing. Each board needs to be tested individually before combining into the integrated digital electronics system. Each board needs critical timing signals from the others to be able to operate. A bench test system was developed to support test of each board. The test system produces all the outputs of the control and timing unit, and is delivered much earlier than the timing unit. Timing signals are treated as data. A large file is generated containing the state of every timing signal at any instant. This file is streamed out to an IO card, which is wired directly to the device-under-test (DUT) input pins. This provides a flexible test environment that can be adapted to any of the boards required to test in a standalone configuration. The problem of generating the critical timing signals is then transferred from a hardware problem to a software problem where it is more easily dealt with.

Berkun, Andrew C.↗
NASA NTRS1977

Low-speed wind tunnel tests of 1/9-scale model of a variable-sweep supersonic cruise aircraft

Tests were conducted in the Langley full-scale tunnel to determine the aerodynamic characteristics at low subsonic speeds of a 1/9-scale model of a variable-sweep supersonic cruise aircraft. The model configurations investigated were the basic unflapped arrangement, a take-off flap arrangement, and a landing flap arrangement with several strake leading-edge flow control devices. The tests were conducted at angles of attack from about -5 to 36 deg, sideslip angles from -5 to 10 deg.

Mclemore, H. C.↗
DOE OSTI2014

Semiconductor neutron detectors using depleted uranium oxide

This paper reports on recent attempts to develop and test a new type of solid-state neutron detector fabricated from uranium compounds. It has been known for many years that uranium oxide (UO2), triuranium octoxide (U3O8) and other uranium compounds exhibit semiconducting characteristics with a broad range of electrical properties. We seek to exploit these characteristics to make a direct-conversion semiconductor neutron detector. In such a device a neutron interacts with a uranium nucleus, inducing ssion. The ssion products deposit energy-producing, detectable electron-hole pairs. The high energy released in the ssion reaction indicates that noise discrimination in such a device has the potential to be excellent. Schottky devices were fabricated using a chemical deposition coating technique to deposit UO2 layers a few microns thick on a sapphire substrate. Schottky devices have also been made using a single crystal from UO2 samples approximately 500 microns thick. Neutron sensitivity simulations have been performed using GEANT4. Neutron sensitivity for the Schottky devices was tested experimentally using a 252Cf source.

neutron detection, uranium oxide, semiconductor↗