Advanced Electrical Materials and Components Being Developed

NASA Technical Reports Server (NTRS)

Schwarze, Gene E.

2004-01-01

All aerospace systems require power management and distribution (PMAD) between the energy and power source and the loads. The PMAD subsystem can be broadly described as the conditioning and control of unregulated power from the energy source and its transmission to a power bus for distribution to the intended loads. All power and control circuits for PMAD require electrical components for switching, energy storage, voltage-to-current transformation, filtering, regulation, protection, and isolation. Advanced electrical materials and component development technology is a key technology to increasing the power density, efficiency, reliability, and operating temperature of the PMAD. The primary means to develop advanced electrical components is to develop new and/or significantly improved electronic materials for capacitors, magnetic components, and semiconductor switches and diodes. The next important step is to develop the processing techniques to fabricate electrical and electronic components that exceed the specifications of presently available state-of-the-art components. The NASA Glenn Research Center's advanced electrical materials and component development technology task is focused on the following three areas: 1) New and/or improved dielectric materials for the development of power capacitors with increased capacitance volumetric efficiency, energy density, and operating temperature; 2) New and/or improved high-frequency, high-temperature soft magnetic materials for the development of transformers and inductors with increased power density, energy density, electrical efficiency, and operating temperature; 3) Packaged high-temperature, high-power density, high-voltage, and low-loss SiC diodes and switches.

Alternative Fuels Data Center: How Do All-Electric Cars Work?

Science.gov Websites

charge while charging the pack. Power electronics controller: This unit manages the flow of electrical of the engine, electric motor, power electronics, and other components. Traction battery pack: Stores

Tritium-powered radiation sensor network

NASA Astrophysics Data System (ADS)

Litz, Marc S.; Russo, Johnny A.; Katsis, Dimos

2016-05-01

Isotope power supplies offer long-lived (100 years using 63Ni), low-power energy sources, enabling sensors or communications nodes for the lifetime of infrastructure. A tritium beta-source (12.5-year half-life) encapsulated in a phosphor-lined vial couples directly to a photovoltaic (PV) to generate a trickle current into an electrical load. An inexpensive design is described using commercial-of-the-shelf (COTS) components that generate 100 μWe for nextgeneration compact electronics/sensors. A matched radiation sensor has been built for long-duration missions utilizing microprocessor-controlled sleep modes, low-power electronic components, and a passive interrupt driven environmental wake-up. The low-power early-warning radiation detector network and isotope power source enables no-maintenance mission lifetimes.

System and method for generating steady state confining current for a toroidal plasma fusion reactor

DOEpatents

Fisch, Nathaniel J.

1981-01-01

A system for generating steady state confining current for a toroidal plasma fusion reactor providing steady-state generation of the thermonuclear power. A dense, hot toroidal plasma is initially prepared with a confining magnetic field with toroidal and poloidal components. Continuous wave RF energy is injected into said plasma to establish a spectrum of traveling waves in the plasma, where the traveling waves have momentum components substantially either all parallel, or all anti-parallel to the confining magnetic field. The injected RF energy is phased to couple to said traveling waves with both a phase velocity component and a wave momentum component in the direction of the plasma traveling wave components. The injected RF energy has a predetermined spectrum selected so that said traveling waves couple to plasma electrons having velocities in a predetermined range .DELTA.. The velocities in the range are substantially greater than the thermal electron velocity of the plasma. In addition, the range is sufficiently broad to produce a raised plateau having width .DELTA. in the plasma electron velocity distribution so that the plateau electrons provide steady-state current to generate a poloidal magnetic field component sufficient for confining the plasma. In steady state operation of the fusion reactor, the fusion power density in the plasma exceeds the power dissipated in the plasma.

System and method for generating steady state confining current for a toroidal plasma fusion reactor

DOEpatents

Bers, Abraham

1981-01-01

A system for generating steady state confining current for a toroidal plasma fusion reactor providing steady-state generation of the thermonuclear power. A dense, hot toroidal plasma is initially prepared with a confining magnetic field with toroidal and poloidal components. Continuous wave RF energy is injected into said plasma to estalish a spectrum of traveling waves in the plasma, where the traveling waves have momentum components substantially either all parallel, or all anti-parallel to the confining magnetic field. The injected RF energy is phased to couple to said traveling waves with both a phase velocity component and a wave momentum component in the direction of the plasma traveling wave components. The injected RF energy has a predetermined spectrum selected so that said traveling waves couple to plasma electrons having velocities in a predetermined range .DELTA.. The velocities in the range are substantially greater than the thermal electron velocity of the plasma. In addition, the range is sufficiently broad to produce a raised plateau having width .DELTA. in the plasma electron velocity distribution so that the plateau electrons provide steady-state current to generate a poloidal magnetic field component sufficient for confining the plasma. In steady state operation of the fusion reactor, the fusion power density in the plasma exceeds the power dissipated inthe plasma.

Alternative Fuels Data Center: How Do Plug-In Hybrid Electric Cars Work?

Science.gov Websites

the pack. Power electronics controller: This unit manages the flow of electrical energy delivered by , electric motor, power electronics, and other components. Traction battery pack: Stores electricity for use

RF Design of a High Average Beam-Power SRF Electron Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sipahi, Nihan; Biedron, Sandra; Gonin, Ivan

2016-06-01

There is a significant interest in developing high-average power electron sources, particularly in the area of electron sources integrated with Superconducting Radio Frequency (SRF) systems. For these systems, the electron gun and cathode parts are critical components for stable intensity and high-average powers. In this initial design study, we will present the design of a 9-cell accelerator cavity having a frequency of 1.3 GHz and the corresponding field optimization studies.

Thermal Performance Benchmarking

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, Xuhui; Moreno, Gilbert; Bennion, Kevin

2016-06-07

The goal for this project is to thoroughly characterize the thermal performance of state-of-the-art (SOA) in-production automotive power electronics and electric motor thermal management systems. Information obtained from these studies will be used to: evaluate advantages and disadvantages of different thermal management strategies; establish baseline metrics for the thermal management systems; identify methods of improvement to advance the SOA; increase the publicly available information related to automotive traction-drive thermal management systems; help guide future electric drive technologies (EDT) research and development (R&D) efforts. The thermal performance results combined with component efficiency and heat generation information obtained by Oak Ridge Nationalmore » Laboratory (ORNL) may then be used to determine the operating temperatures for the EDT components under drive-cycle conditions. In FY16, the 2012 Nissan LEAF power electronics and 2014 Honda Accord Hybrid power electronics thermal management system were characterized. Comparison of the two power electronics thermal management systems was also conducted to provide insight into the various cooling strategies to understand the current SOA in thermal management for automotive power electronics and electric motors.« less

Electric vehicle recycling 2020: Key component power electronics.

PubMed

Bulach, Winfried; Schüler, Doris; Sellin, Guido; Elwert, Tobias; Schmid, Dieter; Goldmann, Daniel; Buchert, Matthias; Kammer, Ulrich

2018-04-01

Electromobility will play a key role in order to reach the specified ambitious greenhouse gas reduction targets in the German transport sector of 42% between 1990 and 2030. Subsequently, a significant rise in the sale of electric vehicles (EVs) is to be anticipated in future. The amount of EVs to be recycled will rise correspondingly after a delay. This includes the recyclable power electronics modules which are incorporated in every EV as an important component for energy management. Current recycling methods using car shredders and subsequent post shredder technologies show high recycling rates for the bulk metals but are still associated with high losses of precious and strategic metals such as gold, silver, platinum, palladium and tantalum. For this reason, the project 'Electric vehicle recycling 2020 - key component power electronics' developed an optimised recycling route for recycling power electronics modules from EVs which is also practicable in series production and can be implemented using standardised technology. This 'WEEE recycling route' involves the disassembly of the power electronics from the vehicle and a subsequent recycling in an electronic end-of-life equipment recycling plant. The developed recycling process is economical under the current conditions and raw material prices, even though it involves considerably higher costs than recycling using the car shredder. The life cycle assessment shows basically good results, both for the traditional car shredder route and the developed WEEE recycling route: the latter provides additional benefits from some higher recovery rates and corresponding credits.

Prognostics of Power Electronics, Methods and Validation Experiments

NASA Technical Reports Server (NTRS)

Kulkarni, Chetan S.; Celaya, Jose R.; Biswas, Gautam; Goebel, Kai

2012-01-01

Abstract Failure of electronic devices is a concern for future electric aircrafts that will see an increase of electronics to drive and control safety-critical equipment throughout the aircraft. As a result, investigation of precursors to failure in electronics and prediction of remaining life of electronic components is of key importance. DC-DC power converters are power electronics systems employed typically as sourcing elements for avionics equipment. Current research efforts in prognostics for these power systems focuses on the identification of failure mechanisms and the development of accelerated aging methodologies and systems to accelerate the aging process of test devices, while continuously measuring key electrical and thermal parameters. Preliminary model-based prognostics algorithms have been developed making use of empirical degradation models and physics-inspired degradation model with focus on key components like electrolytic capacitors and power MOSFETs (metal-oxide-semiconductor-field-effect-transistor). This paper presents current results on the development of validation methods for prognostics algorithms of power electrolytic capacitors. Particularly, in the use of accelerated aging systems for algorithm validation. Validation of prognostics algorithms present difficulties in practice due to the lack of run-to-failure experiments in deployed systems. By using accelerated experiments, we circumvent this problem in order to define initial validation activities.

Controlled cooling of an electronic system for reduced energy consumption

DOE Office of Scientific and Technical Information (OSTI.GOV)

David, Milnes P.; Iyengar, Madhusudan K.; Schmidt, Roger R.

Energy efficient control of a cooling system cooling an electronic system is provided. The control includes automatically determining at least one adjusted control setting for at least one adjustable cooling component of a cooling system cooling the electronic system. The automatically determining is based, at least in part, on power being consumed by the cooling system and temperature of a heat sink to which heat extracted by the cooling system is rejected. The automatically determining operates to reduce power consumption of the cooling system and/or the electronic system while ensuring that at least one targeted temperature associated with the coolingmore » system or the electronic system is within a desired range. The automatically determining may be based, at least in part, on one or more experimentally obtained models relating the targeted temperature and power consumption of the one or more adjustable cooling components of the cooling system.« less

High Power Klystrons for Efficient Reliable High Power Amplifiers.

DTIC Science & Technology

1980-11-01

techniques to obtain high overall efficiency. One is second harmonic space charge bunching. This is a process whereby the fundamental and second harmonic...components of the space charge waves in the electron beam of a microwave tube are combined to produce more highly concentrated electron bunches raising the...the drift lengths to enhance the 2nd harmonic component in the space charge waves. The latter method was utilized in the VKC-7790. Computer

Evaluation of the Benefits of High Temperature Electronics for Lunar Power Systems

NASA Technical Reports Server (NTRS)

Fay, Edgar H.

1992-01-01

A comparative evaluation is conducted of several approaches to the cooling of a lunar power system's power electronics, in view of the 400 K temperature of the 354-hour lunar day and lunar dust accumulation, which can contaminate power components and radiator surfaces. It is noted that, by raising the power electronics' baseplate temperature to 480 K, no thermal control system is required; the surface of the baseplate acts as its own, waste-heat-rejecting radiator, but the baseplate must be kept clean of lunar dust contamination.

Miniature, low-power X-ray tube using a microchannel electron generator electron source

NASA Technical Reports Server (NTRS)

Elam, Wm. Timothy (Inventor); Kelliher, Warren C. (Inventor); Hershyn, William (Inventor); DeLong, David P. (Inventor)

2011-01-01

Embodiments of the invention provide a novel, low-power X-ray tube and X-ray generating system. Embodiments of the invention use a multichannel electron generator as the electron source, thereby increasing reliability and decreasing power consumption of the X-ray tube. Unlike tubes using a conventional filament that must be heated by a current power source, embodiments of the invention require only a voltage power source, use very little current, and have no cooling requirements. The microchannel electron generator comprises one or more microchannel plates (MCPs), Each MCP comprises a honeycomb assembly of a plurality of annular components, which may be stacked to increase electron intensity. The multichannel electron generator used enables directional control of electron flow. In addition, the multichannel electron generator used is more robust than conventional filaments, making the resulting X-ray tube very shock and vibration resistant.

Advanced Power Electronics Components

NASA Technical Reports Server (NTRS)

Schwarze, Gene E.

2004-01-01

This paper will give a description and status of the Advanced Power Electronics Materials and Components Technology program being conducted by the NASA Glenn Research Center for future aerospace power applications. The focus of this research program is on the following: 1) New and/or significantly improved dielectric materials for the development of power capacitors with increased volumetric efficiency, energy density, and operating temperature. Materials being investigated include nanocrystalline and composite ceramic dielectrics and diamond-like carbon films; 2) New and/or significantly improved high frequency, high temperature, low loss soft magnetic materials for the development of transformers/inductors with increased power/energy density, electrical efficiency, and operating temperature. Materials being investigated include nanocrystalline and nanocomposite soft magnetic materials; 3) Packaged high temperature, high power density, high voltage, and low loss SiC diodes and switches. Development of high quality 4H- and 6H- SiC atomically smooth substrates to significantly improve device performance is a major emphasis of the SiC materials program; 4) Demonstration of high temperature (> 200 C) circuits using the components developed above.

Electronics for Piezoelectric Smart Structures

NASA Technical Reports Server (NTRS)

Warkentin, D. J.; Tani, J.

1997-01-01

This paper briefly presents work addressing some of the basic considerations for the electronic components used in smart structures incorporating piezoelectric elements. After general remarks on the application of piezoelectric elements to the problem of structural vibration control, three main topics are described. Work to date on the development of techniques for embedding electronic components within structural parts is presented, followed by a description of the power flow and dissipation requirements of those components. Finally current work on the development of electronic circuits for use in an 'active wall' for acoustic noise is introduced.

Power SEMICONDUCTORS—STATE of Art and Future Trends

NASA Astrophysics Data System (ADS)

Benda, Vitezslav

2011-06-01

The importance of effective energy conversion control, including power generation from renewable and environmentally clean energy sources, increases due to rising energy demand. Power electronic systems for controlling and converting electrical energy have become the workhorse of modern society in many applications, both in industry and at home. Power electronics plays a very important role in traction and can be considered as brawns of robotics and automated manufacturing systems. Power semiconductor devices are the key electronic components used in power electronic systems. Advances in power semiconductor technology have improved the efficiency, size, weight and cost of power electronic systems. At present, IGCTs, IGBTs, and MOSFETs represent modern switching devices. Power integrated circuits (PIC) have been developed for the use of power converters for portable, automotive and aerospace applications. For advanced applications, new materials (SiC and GaN) have been introduced. This paper reviews the state of these devices and elaborates on their potentials in terms of higher voltages, higher power density, and better switching performance.

DOE Office of Scientific and Technical Information (OSTI.GOV)

David, Milnes P.; Iyengar, Madhusudan K.; Schmidt, Roger R.

Energy efficient control of a cooling system cooling an electronic system is provided. The control includes automatically determining at least one adjusted control setting for at least one adjustable cooling component of a cooling system cooling the electronic system. The automatically determining is based, at least in part, on power being consumed by the cooling system and temperature of a heat sink to which heat extracted by the cooling system is rejected. The automatically determining operates to reduce power consumption of the cooling system and/or the electronic system while ensuring that at least one targeted temperature associated with the coolingmore » system or the electronic system is within a desired range. The automatically determining may be based, at least in part, on one or more experimentally obtained models relating the targeted temperature and power consumption of the one or more adjustable cooling components of the cooling system.« less

Computational electronics and electromagnetics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shang, C C

The Computational Electronics and Electromagnetics thrust area serves as the focal point for Engineering R and D activities for developing computer-based design and analysis tools. Representative applications include design of particle accelerator cells and beamline components; design of transmission line components; engineering analysis and design of high-power (optical and microwave) components; photonics and optoelectronics circuit design; electromagnetic susceptibility analysis; and antenna synthesis. The FY-97 effort focuses on development and validation of (1) accelerator design codes; (2) 3-D massively parallel, time-dependent EM codes; (3) material models; (4) coupling and application of engineering tools for analysis and design of high-power components; andmore » (5) development of beam control algorithms coupled to beam transport physics codes. These efforts are in association with technology development in the power conversion, nondestructive evaluation, and microtechnology areas. The efforts complement technology development in Lawrence Livermore National programs.« less

Radial-Poloidal Mapping of the Energy Distribution of Electrons Accelerated by Lower Hybrid Waves in the Scrape-Off Layer

NASA Astrophysics Data System (ADS)

Gunn, J. P.; Petržílka, V.; Fuchs, V.; Ekedahl, A.; Goniche, M.; Hillaret, J.; Kočan, M.; Saint-Laurent, F.

2009-11-01

According to theory, Landau damping transfers the power carried by the high n//>50 components of the lower hybrid (LH) wave to thermal SOL electrons and stochastically accelerates them up to a few keV [1]. What amounts to a few percent of the injected LH power is thus transported along field lines and strikes plasma facing components, leading to the formation of well known "LH hot spots." We report on the first measurements of both the energy from 0 to 1 keV and the radial-poloidal distributions of the accelerated electrons using a retarding field analyzer. Two distinct electron populations are present : a cold, thermal population with temperatures between 10 and 30 eV, and a suprathermal component. Only partial attenuation of the electron flux was achieved at maximum applied voltage, indicating energies greater than 1 keV. Detailed 2D mapping of the hot spots was obtained by varying the safety factor stepwise during a single discharge. The radial width of the suprathermal electron beam at full power is rather large, at least about 5-6 cm, in contrast to Landau damping theory of the launched wave that predicts the radial width of the hot spots should not exceed a few millimetres [2]. The electron flux far from the grill is intermittent, with a typical burst rate of the order of 10 kHz.

Effectiveness-weighted control of cooling system components

DOEpatents

Campbell, Levi A.; Chu, Richard C.; David, Milnes P.; Ellsworth Jr., Michael J.; Iyengar, Madhusudan K.; Schmidt, Roger R.; Simmons, Robert E.

2015-12-22

Energy efficient control of cooling system cooling of an electronic system is provided based, in part, on weighted cooling effectiveness of the components. The control includes automatically determining speed control settings for multiple adjustable cooling components of the cooling system. The automatically determining is based, at least in part, on weighted cooling effectiveness of the components of the cooling system, and the determining operates to limit power consumption of at least the cooling system, while ensuring that a target temperature associated with at least one of the cooling system or the electronic system is within a desired range by provisioning, based on the weighted cooling effectiveness, a desired target temperature change among the multiple adjustable cooling components of the cooling system. The provisioning includes provisioning applied power to the multiple adjustable cooling components via, at least in part, the determined control settings.

Future Concepts for Modular, Intelligent Aerospace Power Systems

NASA Technical Reports Server (NTRS)

Button, Robert M.; Soeder, James F.

2004-01-01

Nasa's resent commitment to Human and Robotic Space Exploration obviates the need for more affordable and sustainable systems and missions. Increased use of modularity and on-board intelligent technologies will enable these lofty goals. To support this new paradigm, an advanced technology program to develop modular, intelligent power management and distribution (PMAD) system technologies is presented. The many benefits to developing and including modular functionality in electrical power components and systems are shown to include lower costs and lower mass for highly reliable systems. The details of several modular technologies being developed by NASA are presented, broken down into hierarchical levels. Modularity at the device level, including the use of power electronic building blocks, is shown to provide benefits in lowering the development time and costs of new power electronic components.

Power Electronics and Electric Machines | Transportation Research | NREL

Science.gov Websites

-to resource for information from cutting-edge thermal management research, making wide-scale adoption battery, the motor, and other powertrain components. NREL's thermal management and reliability research is thermal management technologies to improve performance, cost, and reliability for power electronics and

Space Power Management and Distribution Status and Trends

NASA Technical Reports Server (NTRS)

Reppucci, G. M.; Biess, J. J.; Inouye, L.

1984-01-01

An overview of space power management and distribution (PMAD) is provided which encompasses historical and current technology trends. The PMAD components discussed include power source control, energy storage control, and load power processing electronic equipment. The status of distribution equipment comprised of rotary joints and power switchgear is evaluated based on power level trends in the public, military, and commercial sectors. Component level technology thrusts, as driven by perceived system level trends, are compared to technology status of piece-parts such as power semiconductors, capacitors, and magnetics to determine critical barriers.

Refrigerant directly cooled capacitors

DOEpatents

Hsu, John S [Oak Ridge, TN; Seiber, Larry E [Oak Ridge, TN; Marlino, Laura D [Oak Ridge, TN; Ayers, Curtis W [Kingston, TN

2007-09-11

The invention is a direct contact refrigerant cooling system using a refrigerant floating loop having a refrigerant and refrigeration devices. The cooling system has at least one hermetic container disposed in the refrigerant floating loop. The hermetic container has at least one electronic component selected from the group consisting of capacitors, power electronic switches and gating signal module. The refrigerant is in direct contact with the electronic component.

Thermal Peak Management Using Organic Phase Change Materials for Latent Heat Storage in Electronic Applications

PubMed Central

Maxa, Jacob; Novikov, Andrej; Nowottnick, Mathias

2017-01-01

Modern high power electronics devices consists of a large amount of integrated circuits for switching and supply applications. Beside the benefits, the technology exhibits the problem of an ever increasing power density. Nowadays, heat sinks that are directly mounted on a device, are used to reduce the on-chip temperature and dissipate the thermal energy to the environment. This paper presents a concept of a composite coating for electronic components on printed circuit boards or electronic assemblies that is able to buffer a certain amount of thermal energy, dissipated from a device. The idea is to suppress temperature peaks in electronic components during load peaks or electronic shorts, which otherwise could damage or destroy the device, by using a phase change material to buffer the thermal energy. The phase change material coating could be directly applied on the chip package or the PCB using different mechanical retaining jigs.

Thermally matched fluid cooled power converter

DOEpatents

Radosevich, Lawrence D.; Kannenberg, Daniel G.; Kaishian, Steven C.; Beihoff, Bruce C.

2005-06-21

A thermal support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. Power electronic circuits are thermally matched, such as between component layers and between the circuits and the support. The support may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

Direct Cooling of Propulsion Drives for High Power Density and Low Volume

DTIC Science & Technology

2005-03-30

and fluid temperature. The heat flux (q") was calculated from the observed data (see Mudawar 2001) as follows: Pd (5) At, where Pd is the power...Electronics Module", Proceedings of the Electronic Components and Technology Conference, ECTC�, Las Vegas, Nevada, May. 20. I. Mudawar (2001

Development of Electronics for Low-Temperature Space Missions

NASA Technical Reports Server (NTRS)

Patterson, Richard L.; Hammoud, Ahmad; Dickman, John E.; Gerber, Scott S.; Overton, Eric

2001-01-01

Electronic systems that are capable of operating at cryogenic temperatures will be needed for many future NASA space missions, including deep space probes and spacecraft for planetary surface exploration. In addition to being able to survive the harsh deep space environment, low-temperature electronics would help improve circuit performance, increase system efficiency, and reduce payload development and launch costs. Terrestrial applications where components and systems must operate in low-temperature environments include cryogenic instrumentation, superconducting magnetic energy storage, magnetic levitation transportation systems, and arctic exploration. An ongoing research and development project for the design, fabrication, and characterization of low-temperature electronics and supporting technologies at NASA Glenn Research Center focuses on efficient power systems capable of surviving in and exploiting the advantages of low-temperature environments. Supporting technologies include dielectric and insulating materials, semiconductor devices, passive power components, optoelectronic devices, and packaging and integration of the developed components into prototype flight hardware. An overview of the project is presented, including a description of the test facilities, a discussion of selected data from component testing, and a presentation of ongoing research activities being performed in collaboration with various organizations.

Power Electronics Thermal Management Research: Annual Progress Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moreno, Gilberto

The objective for this project is to develop thermal management strategies to enable efficient and high-temperature wide-bandgap (WBG)-based power electronic systems (e.g., emerging inverter and DC-DC converter). Reliable WBG devices are capable of operating at elevated temperatures (≥ 175 °Celsius). However, packaging WBG devices within an automotive inverter and operating them at higher junction temperatures will expose other system components (e.g., capacitors and electrical boards) to temperatures that may exceed their safe operating limits. This creates challenges for thermal management and reliability. In this project, system-level thermal analyses are conducted to determine the effect of elevated device temperatures on invertermore » components. Thermal modeling work is then conducted to evaluate various thermal management strategies that will enable the use of highly efficient WBG devices with automotive power electronic systems.« less

Ferroelectric Based High Power Components for L-Band Accelerator Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kanareykin, Alex; Jing, Chunguang; Kostin, Roman

2018-01-16

We are developing a new electronic device to control the power in particle accelerators. The key technology is a new nanostructured material developed by Euclid that changes its properties with an applied electric field. Both superconducting and conventional accelerating structures require fast electronic control of the input rf power. A fast controllable phase shifter would allow for example the control of the rf power delivered to multiple accelerating cavities from a single power amplifier. Nonlinear ferroelectric microwave components can control the tuning or the input power coupling for rf cavities. Applying a bias voltage across a nonlinear ferroelectric changes itsmore » permittivity. This effect can be used to cause a phase change of a propagating rf signal or change the resonant frequency of a cavity. The key is the development of a low loss highly tunable ferroelectric material.« less

Effectiveness-weighted control method for a cooling system

DOEpatents

Campbell, Levi A.; Chu, Richard C.; David, Milnes P.; Ellsworth Jr., Michael J.; Iyengar, Madhusudan K.; Schmidt, Roger R.; Simons, Robert E.

2015-12-15

Energy efficient control of cooling system cooling of an electronic system is provided based, in part, on weighted cooling effectiveness of the components. The control includes automatically determining speed control settings for multiple adjustable cooling components of the cooling system. The automatically determining is based, at least in part, on weighted cooling effectiveness of the components of the cooling system, and the determining operates to limit power consumption of at least the cooling system, while ensuring that a target temperature associated with at least one of the cooling system or the electronic system is within a desired range by provisioning, based on the weighted cooling effectiveness, a desired target temperature change among the multiple adjustable cooling components of the cooling system. The provisioning includes provisioning applied power to the multiple adjustable cooling components via, at least in part, the determined control settings.

FY2012 Advanced Power Electronics and Electric Motors Annual Progress Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rogers, Susan A.

The Advanced Power Electronics and Electric Motors (APEEM) program within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on developing revolutionary new power electronics (PE), electric motor (EM), thermal management, and traction drive system technologies that will leapfrog current on-the-road technologies. The research and development is also aimed at achieving a greater understanding of and improvements in the way the various new components of tomorrow's automobiles will function as a unified system to improve fuel efficiency.

FY2010 Annual Progress Report for Advanced Power Electronics and Electric Motors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rogers, Susan A.

2011-01-01

The Advanced Power Electronics and Electric Machines (APEEM) subprogram within the Vehicle Technologies Program provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on developing revolutionary new power electronics (PE) and electric motor technologies that will leapfrog current on-the-road technologies. The research and development (R&D) is also aimed at achieving a greater understanding of and improvements in the way the various new components of tomorrow’s automobiles will function as a unified system to improve fuel efficiency.

Actively controlling coolant-cooled cold plate configuration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chainer, Timothy J.; Parida, Pritish R.

Cooling apparatuses are provided to facilitate active control of thermal and fluid dynamic performance of a coolant-cooled cold plate. The cooling apparatus includes the cold plate and a controller. The cold plate couples to one or more electronic components to be cooled, and includes an adjustable physical configuration. The controller dynamically varies the adjustable physical configuration of the cold plate based on a monitored variable associated with the cold plate or the electronic component(s) being cooled by the cold plate. By dynamically varying the physical configuration, the thermal and fluid dynamic performance of the cold plate are adjusted to, formore » example, optimally cool the electronic component(s), and at the same time, reduce cooling power consumption used in cooling the electronic component(s). The physical configuration can be adjusted by providing one or more adjustable plates within the cold plate, the positioning of which may be adjusted based on the monitored variable.« less

Study of multipactor suppression of microwave components using perforated waveguide technology for space applications

NASA Astrophysics Data System (ADS)

Ye, Ming; Li, Yun; He, Yongning; Daneshmand, Mojgan

2017-05-01

With the development of space technology, microwave components with increased power handling capability and reduced weight have been urgently required. In this work, the perforated waveguide technology is proposed to suppress the multipactor effect of high power microwave components. Meanwhile, this novel method has the advantage of reducing components' weight, which makes it to have great potential in space applications. The perforated part of the waveguide components can be seen as an electron absorber (namely, its total electron emission yield is zero) since most of the electrons impacting on this part will go out of the components. Based on thoroughly benchmarked numerical simulation procedures, we simulated an S band and an X band waveguide transformer to conceptually verify this idea. Both electron dynamic simulations and electrical loss simulations demonstrate that the perforation technology can improve the multipactor threshold at least ˜8 dB while maintaining the acceptable insertion loss level compared with its un-perforated components. We also found that the component with larger minimum gap is easier to achieve multipactor suppression. This effect is interpreted by a parallel plate waveguide model. What's more, to improve the multipactor threshold of the X band waveguide transformer with a minimum gap of ˜0.1 mm, we proposed a perforation structure with the slope edge and explained its mechanism. Future study will focus on further optimization of the perforation structure, size, and distribution to maximize the comprehensive performances of microwave components.

Cryogenic applications of commercial electronic components

NASA Astrophysics Data System (ADS)

Buchanan, Ernest D.; Benford, Dominic J.; Forgione, Joshua B.; Harvey Moseley, S.; Wollack, Edward J.

2012-10-01

We have developed a range of techniques useful for constructing analog and digital circuits for operation in a liquid Helium environment (4.2 K), using commercially available low power components. The challenges encountered in designing cryogenic electronics include finding components that can function usefully in the cold and possess low enough power dissipation so as not to heat the systems they are designed to measure. From design, test, and integration perspectives it is useful for components to operate similarly at room and cryogenic temperatures; however this is not a necessity. Some of the circuits presented here have been used successfully in the MUSTANG [1] and in the GISMO [2] camera to build a complete digital to analog multiplexer (which will be referred to as the Cryogenic Address Driver board). Many of the circuit elements described are of a more general nature rather than specific to the Cryogenic Address Driver board, and were studied as a part of a more comprehensive approach to addressing a larger set of cryogenic electronic needs.

Cryogenic Applications of Commercial Electronic Components

NASA Technical Reports Server (NTRS)

Buchanan, Ernest D.; Benford, Dominic J.; Forgione, Joshua B.; Moseley, S. Harvey; Wollack, Edward J.

2012-01-01

We have developed a range of techniques useful for constructing analog and digital circuits for operation in a liquid Helium environment (4.2K), using commercially available low power components. The challenges encountered in designing cryogenic electronics include finding components that can function usefully in the cold and possess low enough power dissipation so as not to heat the systems they are designed to measure. From design, test, and integration perspectives it is useful for components to operate similarly at room and cryogenic temperatures; however this is not a necessity. Some of the circuits presented here have been used successfully in the MUSTANG and in the GISMO camera to build a complete digital to analog multiplexer (which will be referred to as the Cryogenic Address Driver board). Many of the circuit elements described are of a more general nature rather than specific to the Cryogenic Address Driver board, and were studied as a part of a more comprehensive approach to addressing a larger set of cryogenic electronic needs.

Types of Hearing Aids

MedlinePlus

... hearing impairment. Most hearing aids share several similar electronic components, including a microphone that picks up sound; ... the ear canal; and batteries that power the electronic parts. Hearing aids differ by: design technology used ...

Aging of electronics with application to nuclear power plant instrumentation. [PWR; BWR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Jr, R T; Thome, F V; Craft, C M

1983-01-01

A survey to identify areas of needed research to understand aging mechanisms for electronics in nuclear power plant instrumentation has been completed. The emphasis was on electronic components such as semiconductors, capacitors, and resistors used in safety-related instrumentation in the reactor containment area. The environmental and operational stress factors which may produce degradation during long-term operation were identified. Some attention was also given to humidity effects as related to seals and encapsulants, and failures in printed circuit boards and bonds and solder joints. Results suggest that neutron as well as gamma irradiations should be considered in simulating the aging environmentmore » for electronic components. Radiation dose-rate effects in semiconductor devices and organic capacitors need to be further investigated, as well as radiation-voltage bias synergistic effects in semiconductor devices and leakage and permeation of moisture through seals in electronics packages.« less

Solar powered hybrid sensor module program

NASA Technical Reports Server (NTRS)

Johnson, J. M.; Holmes, H. K.

1985-01-01

Geo-orbital systems of the near future will require more sophisticated electronic and electromechanical monitoring and control systems than current satellite systems with an emphasis in the design on the electronic density and autonomy of the subsystem components. Results of a project to develop, design, and implement a proof-of-concept sensor system for space applications, with hybrids forming the active subsystem components are described. The design of the solar power hybrid sensor modules is discussed. Module construction and function are described. These modules combined low power CMOS electronics, GaAs solar cells, a crystal oscillatory standard UART data formatting, and a bidirectional optical data link into a single 1.25 x 1.25 x 0.25 inch hybrid package which has no need for electrical input or output. Several modules were built and tested. Applications of such a system for future space missions are also discussed.

A large-area wireless power-transmission sheet using printed organic transistors and plastic MEMS switches.

PubMed

Sekitani, Tsuyoshi; Takamiya, Makoto; Noguchi, Yoshiaki; Nakano, Shintaro; Kato, Yusaku; Sakurai, Takayasu; Someya, Takao

2007-06-01

The electronics fields face serious problems associated with electric power; these include the development of ecologically friendly power-generation systems and ultralow-power-consuming circuits. Moreover, there is a demand for developing new power-transmission methods in the imminent era of ambient electronics, in which a multitude of electronic devices such as sensor networks will be used in our daily life to enhance security, safety and convenience. We constructed a sheet-type wireless power-transmission system by using state-of-the-art printing technologies using advanced electronic functional inks. This became possible owing to recent progress in organic semiconductor technologies; the diversity of chemical syntheses and processes on organic materials has led to a new class of organic semiconductors, dielectric layers and metals with excellent electronic functionalities. The new system directly drives electronic devices by transmitting power of the order of tens of watts without connectors, thereby providing an easy-to-use and reliable power source. As all of the components are manufactured on plastic films, it is easy to place the wireless power-transmission sheet over desks, floors, walls and any other location imaginable.

Computational electronics and electromagnetics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shang, C. C.

The Computational Electronics and Electromagnetics thrust area at Lawrence Livermore National Laboratory serves as the focal point for engineering R&D activities for developing computer-based design, analysis, and tools for theory. Key representative applications include design of particle accelerator cells and beamline components; engineering analysis and design of high-power components, photonics, and optoelectronics circuit design; EMI susceptibility analysis; and antenna synthesis. The FY-96 technology-base effort focused code development on (1) accelerator design codes; (2) 3-D massively parallel, object-oriented time-domain EM codes; (3) material models; (4) coupling and application of engineering tools for analysis and design of high-power components; (5) 3-D spectral-domainmore » CEM tools; and (6) enhancement of laser drilling codes. Joint efforts with the Power Conversion Technologies thrust area include development of antenna systems for compact, high-performance radar, in addition to novel, compact Marx generators. 18 refs., 25 figs., 1 tab.« less

Compton scattering of self-absorbed synchrotron emission

NASA Astrophysics Data System (ADS)

Gao, He; Lei, Wei-Hua; Wu, Xue-Feng; Zhang, Bing

2013-11-01

Synchrotron self-Compton (SSC) scattering is an important emission mechanism in many astronomical sources, such as gamma-ray bursts (GRBs) and active galactic nuclei. We give a complete presentation of the analytical approximations for the Compton scattering of synchrotron emission with both weak and strong synchrotron self-absorption. All possible orders of the characteristic synchrotron spectral breaks (νa, νm and νc) are studied. In the weak self-absorption regime, i.e. νa < νc, the electron energy distribution is not modified by the self-absorption process. The shape of the SSC component broadly resembles that of synchrotron, but with the following features: The SSC flux increases linearly with frequency up to the SSC break frequency corresponding to the self-absorption frequency νa; and the presence of a logarithmic term in the high-frequency range of the SSC spectra makes it harder than the power-law approximation. In the strong absorption regime, i.e. νa > νc, heating of low-energy electrons due to synchrotron absorption leads to pile-up of electrons, and form a thermal component besides the broken power-law component. This leads to two-component (thermal + non-thermal) spectra for both the synchrotron and SSC spectral components. For νc < νa < νm, the spectrum is thermal (non-thermal) dominated if ν _a > √{ν _m ν _c} (ν _a < √{ν _m ν _c}). Similar to the weak-absorption regime, the SSC spectral component is broader than the simple broken power-law approximation. We derive the critical condition for strong absorption (electron pile-up), and discuss a case of GRB reverse shock emission in a wind medium, which invokes νa > max(νm, νc).

Observation of ultrahigh-energy electrons by resonance absorption of high-power microwaves in a pulsed plasma.

PubMed

Rajyaguru, C; Fuji, T; Ito, H; Yugami, N; Nishida, Y

2001-07-01

The interaction of high power microwave with collisionless unmagnetized plasma is studied. Investigation on the generation of superthermal electrons near the critical layer, by the resonance absorption phenomenon, is extended to very high microwave power levels (eta=E(2)(0)/4 pi n(e)kT(e) approximately 0.3). Here E0, n(e), and T(e) are the vacuum electric field, electron density, and electron temperature, respectively. Successive generation of electron bunches having maximum energy of about 2 keV, due to nonlinear wave breaking, is observed. The electron energy epsilon scales as a function of the incident microwave power P, according to epsilon proportional to P0.5 up to 250 kW. The two-dimensional spatial distribution of high energy electrons reveals that they are generated near the critical layer. However, the lower energy component is again produced in the subcritical density region indicating the possibility of other electron heating mechanisms.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harper, Jason; Dobrzynski, Daniel S.

A smart charging system for charging a plug-in electric vehicle (PEV) includes an electric vehicle supply equipment (EVSE) configured to supply electrical power to the PEV through a smart charging module coupled to the EVSE. The smart charging module comprises an electronic circuitry which includes a processor. The electronic circuitry includes electronic components structured to receive electrical power from the EVSE, and supply the electrical power to the PEV. The electronic circuitry is configured to measure a charging parameter of the PEV. The electronic circuitry is further structured to emulate a pulse width modulated signal generated by the EVSE. Themore » smart charging module can also include a first coupler structured to be removably couple to the EVSE and a second coupler structured to be removably coupled to the PEV.« less

Modeling Single-Phase and Boiling Liquid Jet Impingement Cooling in Power Electronics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Narumanchi, S. V. J.; Hassani, V.; Bharathan, D.

2005-12-01

Jet impingement has been an attractive cooling option in a number of industries over the past few decades. Over the past 15 years, jet impingement has been explored as a cooling option in microelectronics. Recently, interest has been expressed by the automotive industry in exploring jet impingement for cooling power electronics components. This technical report explores, from a modeling perspective, both single-phase and boiling jet impingement cooling in power electronics, primarily from a heat transfer viewpoint. The discussion is from the viewpoint of the cooling of IGBTs (insulated-gate bipolar transistors), which are found in hybrid automobile inverters.

FY2011 Advanced Power Electronics and Electric Motors Annual Progress Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rogers, Susan A.

The Advanced Power Electronics and Electric Motors (APEEM) program within the DOE Vehicle Technologies Program (VTP) provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on developing revolutionary new power electronics (PE), electric motor (EM), thermal management, and traction drive system technologies that will leapfrog current on-the-road technologies. The research and development (R&D) is also aimed at achieving a greater understanding of and improvements in the way the various new components of tomorrow’s automobiles will function as a unified system to improve fuel efficiency.

Self-similar and fractal design for stretchable electronics

DOEpatents

Rogers, John A.; Fan, Jonathan; Yeo, Woon-Hong; Su, Yewang; Huang, Yonggang; Zhang, Yihui

2017-04-04

The present invention provides electronic circuits, devices and device components including one or more stretchable components, such as stretchable electrical interconnects, electrodes and/or semiconductor components. Stretchability of some of the present systems is achieved via a materials level integration of stretchable metallic or semiconducting structures with soft, elastomeric materials in a configuration allowing for elastic deformations to occur in a repeatable and well-defined way. The stretchable device geometries and hard-soft materials integration approaches of the invention provide a combination of advance electronic function and compliant mechanics supporting a broad range of device applications including sensing, actuation, power storage and communications.

Palm Power Free-Piston Stirling Engine Control Electronics

NASA Astrophysics Data System (ADS)

Keiter, Douglas E.; Holliday, Ezekiel

2007-01-01

A prototype 35We, JP-8 fueled, soldier-wearable power system for the DARPA Palm Power program has been developed and tested by Sunpower. A hermetically-sealed 42We Sunpower Free-Piston Stirling Engine (FPSE) with integral linear alternator is the prime mover for this system. To maximize system efficiency over a broad range of output power, a non-dissipative, highly efficient electronic control system which modulates engine output power by varying piston stroke and converts the AC output voltage of the FPSE into 28Vdc for the Palm Power end user, has been designed and demonstrated as an integral component of the Palm Power system. This paper reviews the current status and progress made in developing the control electronics for the Palm Power system, in addition to describing the operation and demonstrated performance of the engine controller in the context of the current JP-8 fueled Palm Power system.

Radiation Specifications for Fission Power Conversion Component Materials

NASA Technical Reports Server (NTRS)

Bowman, Cheryl L.; Shin, E. Eugene; Mireles, Omar R.; Radel, Ross F.; Qualls, A. Louis

2011-01-01

NASA has been supporting design studies and technology development that could provide power to an outpost on the moon, Mars, or an asteroid. One power-generation system that is independent of sunlight or power-storage limitations is a fission-based power plant. There is a wealth of terrestrial system heritage that can be transferred to the design and fabrication of a fission power system for space missions, but there are certain design aspects that require qualification. The radiation tolerance of the power conversion system requires scrutiny because the compact nature of a space power plant restricts the dose reduction methodologies compared to those used in terrestrial systems. An integrated research program has been conducted to establish the radiation tolerance of power conversion system-component materials. The radiation limit specifications proposed for a Fission Power System power convertor is 10 Mrad ionizing dose and 5 x 10(exp 14) neutron per square centimeter fluence for a convertor operating at 150 C. Specific component materials and their radiation tolerances are discussed. This assessment is for the power convertor hardware; electronic components are not covered here.

Thermal Management and Reliability of Automotive Power Electronics and Electric Machines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Narumanchi, Sreekant V; Bennion, Kevin S; Cousineau, Justine E

Low-cost, high-performance thermal management technologies are helping meet aggressive power density, specific power, cost, and reliability targets for power electronics and electric machines. The National Renewable Energy Laboratory is working closely with numerous industry and research partners to help influence development of components that meet aggressive performance and cost targets through development and characterization of cooling technologies, and thermal characterization and improvements of passive stack materials and interfaces. Thermomechanical reliability and lifetime estimation models are important enablers for industry in cost-and time-effective design.

Advanced Self-Calibrating, Self-Repairing Data Acquisition System

NASA Technical Reports Server (NTRS)

Medelius, Pedro J. (Inventor); Eckhoff, Anthony J. (Inventor); Angel, Lucena R. (Inventor); Perotti, Jose M. (Inventor)

2002-01-01

An improved self-calibrating and self-repairing Data Acquisition System (DAS) for use in inaccessible areas, such as onboard spacecraft, and capable of autonomously performing required system health checks, failure detection. When required, self-repair is implemented utilizing a "spare parts/tool box" system. The available number of spare components primarily depends upon each component's predicted reliability which may be determined using Mean Time Between Failures (MTBF) analysis. Failing or degrading components are electronically removed and disabled to reduce power consumption, before being electronically replaced with spare components.

Vehicle drive module having improved cooling configuration

DOEpatents

Radosevich, Lawrence D.; Meyer, Andreas A.; Kannenberg, Daniel G.; Kaishian, Steven C.; Beihoff, Bruce C.

2007-02-13

An electric vehicle drive includes a thermal support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. Power electronic circuits are thermally matched, such as between component layers and between the circuits and the support. The support may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

Power Electronics Thermal Management R&D (Presentation)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waye, S.

2014-11-01

This project will investigate and develop thermal-management strategies for wide bandgap (WBG)-based power electronics systems. Research will be carried out to deal with thermal aspects at the module- and system-level. Module-level research will focus on die- and substrate-integrated cooling strategies and heat-transfer enhancement technologies. System-level research will focus on thermal-management strategies for the entire power electronics system to enable smart packaging solutions. One challenge with WBG device-based power electronics is that although losses in the form of heat may be lower, the footprint of the components is also likely to be reduced to reduce cost, weight, and volume. Combined withmore » higher operational temperatures, this creates higher heat fluxes which much be removed from a smaller footprint, requiring advanced cooling strategies.« less

Power converter having improved terminal structure

DOEpatents

Radosevich, Lawrence D.; Kannenberg, Daniel G.; Phillips, Mark G.; Kaishian, Steven C.

2007-03-06

A terminal structure for power electronics circuits reduces the need for a DC bus and thereby the incidence of parasitic inductance. The structure is secured to a support that may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as by direct contact between the terminal assembly and AC and DC circuit components. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

Air-Cooled Heat Exchanger for High-Temperature Power Electronics: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waye, S. K.; Lustbader, J.; Musselman, M.

2015-05-06

This work demonstrates a direct air-cooled heat exchanger strategy for high-temperature power electronic devices with an application specific to automotive traction drive inverters. We present experimental heat dissipation and system pressure curves versus flow rate for baseline and optimized sub-module assemblies containing two ceramic resistance heaters that provide device heat fluxes. The maximum allowable junction temperature was set to 175 deg.C. Results were extrapolated to the inverter scale and combined with balance-of-inverter components to estimate inverter power density and specific power. The results exceeded the goal of 12 kW/L and 12 kW/kg for power density and specific power, respectively.

Materials for bioresorbable radio frequency electronics.

PubMed

Hwang, Suk-Won; Huang, Xian; Seo, Jung-Hun; Song, Jun-Kyul; Kim, Stanley; Hage-Ali, Sami; Chung, Hyun-Joong; Tao, Hu; Omenetto, Fiorenzo G; Ma, Zhenqiang; Rogers, John A

2013-07-12

Materials, device designs and manufacturing approaches are presented for classes of RF electronic components that are capable of complete dissolution in water or biofluids. All individual passive/active components as well as system-level examples such as wireless RF energy harvesting circuits exploit active materials that are biocompatible. The results provide diverse building blocks for physically transient forms of electronics, of particular potential value in bioresorbable medical implants with wireless power transmission and communication capabilities. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Summary of the electromagnetic compatibility evaluation of the proposed satellite power system

NASA Technical Reports Server (NTRS)

Morrison, E. L., Jr.; Grant, W. B.; Davis, K. C.

1980-01-01

The effects of the proposed solar power satellite (SPS) operations on electronic equipment and systems by fundamental, harmonic, and intermodulation component emissions from the orbital station; and the fundamental, harmonic, and structural intermodulation emissions from the rectenna site were evaluated. The coupling and affects interactions affecting a wide spectrum of electronic equipment are considered. The primary EMC tasking areas are each discussed separately.

Power processing

NASA Technical Reports Server (NTRS)

Schwarz, F. C.

1971-01-01

Processing of electric power has been presented as a discipline that draws on almost every field of electrical engineering, including system and control theory, communications theory, electronic network design, and power component technology. The cost of power processing equipment, which often equals that of expensive, sophisticated, and unconventional sources of electrical energy, such as solar batteries, is a significant consideration in the choice of electric power systems.

Low power energy harvesting and storage techniques from ambient human powered energy sources

NASA Astrophysics Data System (ADS)

Yildiz, Faruk

Conventional electrochemical batteries power most of the portable and wireless electronic devices that are operated by electric power. In the past few years, electrochemical batteries and energy storage devices have improved significantly. However, this progress has not been able to keep up with the development of microprocessors, memory storage, and sensors of electronic applications. Battery weight, lifespan and reliability often limit the abilities and the range of such applications of battery powered devices. These conventional devices were designed to be powered with batteries as required, but did not allow scavenging of ambient energy as a power source. In contrast, development in wireless technology and other electronic components are constantly reducing the power and energy needed by many applications. If energy requirements of electronic components decline reasonably, then ambient energy scavenging and conversion could become a viable source of power for many applications. Ambient energy sources can be then considered and used to replace batteries in some electronic applications, to minimize product maintenance and operating cost. The potential ability to satisfy overall power and energy requirements of an application using ambient energy can eliminate some constraints related to conventional power supplies. Also power scavenging may enable electronic devices to be completely self-sustaining so that battery maintenance can eventually be eliminated. Furthermore, ambient energy scavenging could extend the performance and the lifetime of the MEMS (Micro electromechanical systems) and portable electronic devices. These possibilities show that it is important to examine the effectiveness of ambient energy as a source of power. Until recently, only little use has been made of ambient energy resources, especially for wireless networks and portable power devices. Recently, researchers have performed several studies in alternative energy sources that could provide small amounts of electricity to low-power electronic devices. These studies were focused to investigate and obtain power from different energy sources, such as vibration, light, sound, airflow, heat, waste mechanical energy and temperature variations. This research studied forms of ambient energy sources such as waste mechanical (rotational) energy from hydraulic door closers, and fitness exercise bicycles, and its conversion and storage into usable electrical energy. In both of these examples of applications, hydraulic door closers and fitness exercise bicycles, human presence is required. A person has to open the door in order for the hydraulic door closer mechanism to function. Fitness exercise bicycles need somebody to cycle the pedals to generate electricity (while burning calories.) Also vibrations, body motions, and compressions from human interactions were studied using small piezoelectric fiber composites which are capable of recovering waste mechanical energy and converting it to useful electrical energy. Based on ambient energy sources, electrical energy conversion and storage circuits were designed and tested for low power electronic applications. These sources were characterized according to energy harvesting (scavenging) methods, and power and energy density. At the end of the study, the ambient energy sources were matched with possible electronic applications as a viable energy source.

Power supply and pulsing strategies for the future linear colliders

NASA Astrophysics Data System (ADS)

Brogna, A. S.; Göttlicher, P.; Weber, M.

2012-02-01

The concept of the power delivery systems of the future linear colliders exploits the pulsed bunch structure of the beam in order to minimize the average current in the cables and the electronics and thus to reduce the material budget and heat dissipation. Although modern integrated circuit technologies are already available to design a low-power system, the concepts on how to pulse the front-end electronics and further reduce the power are not yet well understood. We propose a possible implementation of a power pulsing system based on a DC/DC converter and we choose the Analog Hadron Calorimeter as a specific example. The model features large switching currents of electronic modules in short time intervals to stimulate the inductive components along the cables and interconnections.

Feedback module for evaluating optical-power stabilization methods

NASA Astrophysics Data System (ADS)

Downing, John

2016-03-01

A feedback module for evaluating the efficacy of optical-power stabilization without thermoelectric coolers (TECs) is described. The module comprises a pickoff optic for sampling a light beam, a photodiode for converting the sample power to electrical current, and a temperature sensor. The components are mounted on an optical bench that makes accurate (0.05°) beam alignment practical as well as providing high thermal-conductivity among the components. The module can be mounted on existing light sources or the components can be incorporated in new designs. Evaluations of optical and electronic stabilization methods are also reported. The optical method combines a novel, weakly reflective, weakly polarizing coating on the pickoff optic with a photodiode and an automatic-power-control (APC) circuit in a closed loop. The shift of emitter wavelength with temperature, coupled with the wavelength-dependent reflectance of the pickoff optic, enable the APC circuit to compensate for temperature errors. In the electronic method, a mixed-signal processor in a quasiclosed loop generates a control signal from temperature and photocurrent inputs and feeds it back to an APC circuit to compensate for temperature errors. These methods result in temperature coefficients less than 20 ppm/°C and relative rms power equal to 05% for the optical method and 0.02% for the electronic method. The later value represents an order of magnitude improvement over rms specifications for cooled, laser-diode modules and a five-fold improvement in wall-plug efficiency is achieved by eliminating TECs.

Equivalent electron fluence for space qualification of shallow junction heteroface GaAs solar cells

NASA Technical Reports Server (NTRS)

Wilson, J. W.; Stock, L. V.

1984-01-01

It is desirable to perform qualification tests prior to deployment of solar cells in space power applications. Such test procedures are complicated by the complex mixture of differing radiation components in space which are difficult to simulate in ground test facilities. Although it has been shown that an equivalent electron fluence ratio cannot be uniquely defined for monoenergetic proton exposure of GaAs shallow junction cells, an equivalent electron fluence test can be defined for common spectral components of protons found in space. Equivalent electron fluence levels for the geosynchronous environment are presented.

Development of 50kV air-core transformer for electron gun static power source of 3MeV DC accelerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dewangan, S.; Bakhtsingh, R.I.; Rajan, R.N.

A 3 MeV, 10 mA DC Electron Beam Accelerator based on the capacitively coupled parallel-fed voltage multiplier in 6 kg/cm{sup 2} SF{sub 6} gas environment is under commissioning at Electron Beam Centre, Kharghar, Navi Mumbai. Electron Gun is situated at -3 MV terminal which requires a constant power for its anode and filament. Gun power source has been derived by suitably coupling the ac components present in the HV Multiplier column. An aircore step down transformer rated for 50kV/600V/120kHz floating at 3 MV to extract the required power for electron gun from high voltage column has been developed. The transformermore » has been operated for 7 kW, 1 MeV of electron beam in 6 kg/cm{sup 2} nitrogen gas environment. The paper describes briefly about the design aspects and test results. (author)« less

Towards Accelerated Aging Methodologies and Health Management of Power MOSFETs (Technical Brief)

NASA Technical Reports Server (NTRS)

Celaya, Jose R.; Patil, Nishad; Saha, Sankalita; Wysocki, Phil; Goebel, Kai

2009-01-01

Understanding aging mechanisms of electronic components is of extreme importance in the aerospace domain where they are part of numerous critical subsystems including avionics. In particular, power MOSFETs are of special interest as they are involved in high voltage switching circuits such as drivers for electrical motors. With increased use of electronics in aircraft control, it becomes more important to understand the degradation of these components in aircraft specific environments. In this paper, we present an accelerated aging methodology for power MOSFETs that subject the devices to indirect thermal overstress during high voltage switching. During this accelerated aging process, two major modes of failure were observed - latch-up and die attach degradation. In this paper we present the details of our aging methodology along with details of experiments and analysis of the results.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lai, Jih-Sheng

This paper introduces control system design based softwares, SIMNON and MATLAB/SIMULINK, for power electronics system simulation. A complete power electronics system typically consists of a rectifier bridge along with its smoothing capacitor, an inverter, and a motor. The system components, featuring discrete or continuous, linear or nonlinear, are modeled in mathematical equations. Inverter control methods,such as pulse-width-modulation and hysteresis current control, are expressed in either computer algorithms or digital circuits. After describing component models and control methods, computer programs are then developed for complete systems simulation. Simulation results are mainly used for studying system performances, such as input and outputmore » current harmonics, torque ripples, and speed responses. Key computer programs and simulation results are demonstrated for educational purposes.« less

Conceptual Design of a 50--100 MW Electron Beam Accelerator System for the National Hypersonic Wind Tunnel Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

SCHNEIDER,LARRY X.

2000-06-01

The National Hypersonic Wind Tunnel program requires an unprecedented electron beam source capable of 1--2 MeV at a beam power level of 50--100 MW. Direct-current electron accelerator technology can readily generate high average power beams to approximately 5 MeV at output efficiencies greater than 90%. However, due to the nature of research and industrial applications, there has never been a requirement for a single module with an output power exceeding approximately 500 kW. Although a 50--100 MW module is a two-order extrapolation from demonstrated power levels, the scaling of accelerator components appears reasonable. This paper presents an evaluation of componentmore » and system issues involved in the design of a 50--100 MW electron beam accelerator system with precision beam transport into a high pressure flowing air environment.« less

Oak Ridge National Laboratory Annual Progress Report for the Power Electronics and Electric Machinery Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszewski, M.

The U.S. Department of Energy (DOE) and the U.S. Council for Automotive Research (composed of automakers Ford, General Motors, and Chrysler) announced in January 2002 a new cooperative research effort. Known as FreedomCAR (derived from 'Freedom' and 'Cooperative Automotive Research'), it represents DOE's commitment to developing public/private partnerships to fund high-risk, high-payoff research into advanced automotive technologies. Efficient fuel cell technology, which uses hydrogen to power automobiles without air pollution, is a very promising pathway to achieve the ultimate vision. The new partnership replaces and builds upon the Partnership for a New Generation of Vehicles initiative that ran from 1993more » through 2001. The Advanced Power Electronics and Electric Machines (APEEM) subprogram within the Vehicle Technologies Program provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on understanding and improving the way the various new components of tomorrow's automobiles will function as a unified system to improve fuel efficiency. In supporting the development of hybrid propulsion systems, the APEEM effort has enabled the development of technologies that will significantly improve advanced vehicle efficiency, costs, and fuel economy. The APEEM subprogram supports the efforts of the FreedomCAR and Fuel Partnership through a three-phase approach intended to: (1) identify overall propulsion and vehicle-related needs by analyzing programmatic goals and reviewing industry's recommendations and requirements and then develop the appropriate technical targets for systems, subsystems, and component research and development activities; (2) develop and validate individual subsystems and components, including electric motors, and power electronics; and (3) determine how well the components and subsystems work together in a vehicle environment or as a complete propulsion system and whether the efficiency and performance targets at the vehicle level have been achieved. The research performed under this subprogram will help remove technical and cost barriers to enable the development of technology for use in such advanced vehicles as hybrid electric vehicles (HEVs), plug-in HEVs, and fuel-cell-powered automobiles that meet the goals of the Vehicle Technologies Program. A key element in making HEVs practical is providing an affordable electric traction drive system. This will require attaining weight, volume, and cost targets for the power electronics and electrical machines subsystems of the traction drive system. Areas of development include these: (1) novel traction motor designs that result in increased power density and lower cost; (2) inverter technologies involving new topologies to achieve higher efficiency and the ability to accommodate higher-temperature environments; (3) converter concepts that employ means of reducing the component count and integrating functionality to decrease size, weight, and cost; (4) more effective thermal control and packaging technologies; and (5) integrated motor/inverter concepts. The Oak Ridge National Laboratory's (ORNL's) Power Electronics and Electric Machinery Research Center conducts fundamental research, evaluates hardware, and assists in the technical direction of the DOE Vehicle Technologies Program, APEEM subprogram. In this role, ORNL serves on the FreedomCAR Electrical and Electronics Technical Team, evaluates proposals for DOE, and lends its technological expertise to the direction of projects and evaluation of developing technologies.« less

Body of Knowledge for Silicon Carbide Power Electronics

NASA Technical Reports Server (NTRS)

Boomer, Kristen; Lauenstein, Jean-Marie; Hammoud, Ahmad

2016-01-01

Wide band gap semiconductors, such as silicon carbide (SiC), have emerged as very promising materials for future electronic components due to the tremendous advantages they offer in terms of power capability, extreme temperature tolerance, and high frequency operation. This report documents some issues pertaining to SiC technology and its application in the area of power electronics, in particular those geared for space missions. It also serves as a body of knowledge (BOK) in reference to the development and status of this technology obtained via literature and industry survey as well as providing a listing of the major manufacturers and their capabilities. Finally, issues relevant to the reliability of SiC-based electronic parts are addressed and limitations affecting the full utilization of this technology are identified.

Vehicle drive module having improved terminal design

DOEpatents

Beihoff, Bruce C.; Radosevich, Lawrence D.; Phillips, Mark G.; Kehl, Dennis L.; Kaishian, Steven C.; Kannenberg, Daniel G.

2006-04-25

A terminal structure for vehicle drive power electronics circuits reduces the need for a DC bus and thereby the incidence of parasitic inductance. The structure is secured to a support that may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as by direct contact between the terminal assembly and AC and DC circuit components. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

Wide-Temperature Electronics for Thermal Control of Nanosats

NASA Technical Reports Server (NTRS)

Dickman, John Ellis; Gerber, Scott

2000-01-01

This document represents a presentation which examines the wide and low-temperature electronics required for NanoSatellites. In the past, larger spacecraft used Radioisotope Heating Units (RHU's). The advantage of the use of these electronics is that they could eliminate or reduce the requirement for RHU's, reduce system weight and simplify spacecraft design by eliminating containment/support structures for RHU's. The Glenn Research Center's Wide/Low Temperature Power Electronics Program supports the development of power systems capable of reliable, efficient operation over wide and low temperature ranges. Included charts review the successes and failures of various electronic devices, the IRF541 HEXFET, The NE76118n-Channel GaAS MESFET, the Lithium Carbon Monofluoride Primary Battery, and a COTS DC-DC converter. The preliminary result of wide/low temperature testing of CTS and custom parts and power circuit indicate that through careful selection of components and technologies it is possible to design and build power circuits which operate from room temperature to near 100K.

Can the cosmic x ray and gamma ray background be due to reflection of a steep power law spectrum and Compton scattering by relativistic electrons?

NASA Technical Reports Server (NTRS)

Zycki, Piotr T.; Zdziarski, Andrzej A.; Svensson, Roland

1991-01-01

We reconsider the recent model for the origin in the cosmic X-ray and gamma-ray background by Rogers and Field. The background in the model is due to an unresolved population of AGNs. An individual AGN spectrum contains three components: a power law with the energy index of alpha = 1.1, an enhanced reflection component, and a component from Compton scattering by relativistic electrons with a low energy cutoff at some minimum Lorentz factor, gamma(sub min) much greater than 1. The MeV bump seen in the gamma-ray background is then explained by inverse Compton emission by the electrons. We show that the model does not reproduce the shape of the observed X-ray and gamma-ray background below 10 MeV and that it overproduces the background at larger energies. Furthermore, we find the assumptions made for the Compton component to be physically inconsistent. Relaxing the inconsistent assumptions leads to model spectra even more different from that of the observed cosmic background. Thus, we can reject the hypothesis that the high-energy cosmic background is due to the described model.

Conformable wearable systems comprising organic electronics on foil for well being and healthcare (presentation video)

NASA Astrophysics Data System (ADS)

de Kok, Margreet M.

2014-10-01

Integration of electronics into materials and objects that have not been functionalized with electronics before, open up extensive possibilities to support mankind. By adding intelligence and/or operating power to materials in close skin contact like clothing, furniture or bandages the health of people can be monitored or even improved. Foil based electronics are interesting components to be integrated as they are thin, large area and cost effective available components Our developed technology of printed electronic structures to which components are reliably bonded, fulfills the promise. We have integrated these components into textiles and built wearable encapsulated products with foil based electronics. Foil components with organic and inorganic LEDs are interconnected and laminated onto electronic textiles by using conductive adhesives to bond the contact pads of the component to conductive yarns in the textile. Modelling and reliability testing under dynamic circumstances provided important insights in order to optimise the technology. The design of the interconnection and choice of conductive adhesive / underfill and lamination contributed to the durability of the system. Transition zones from laminated foil to textile are engineered to withstand dynamic use. As an example of a product, we have realized an electronic wristband that is encapsulated in rubber and has a number of sensor functionalities integrated on stretchable electronic circuits based on Cu and Ag. The encapsulation with silicone or polyurethanes was performed such, that charging and sensor/skin contacts are possible while simultaneously protecting the electronics from mechanical and environmental stresses.

Use of commercial VDMOSFETs in electronic systems subjected to radiation

NASA Astrophysics Data System (ADS)

Picard, C.; Brisset, C.; Quittard, O.; Marceau, M.; Hoffmann, A.; Joffre, F.; Charles, J.-P.

2000-06-01

This study explores the effectiveness of pre-irradiation as a hardening technique for COTS components used in electronic power systems. This technique greatly improves the radiation tolerance of VDMOSFETs in such systems, whereby a small change in R/sub dson/ is observed.

Polarization of photons scattered by electrons in any spectral distribution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Zhe; Lin, Hai-Nan; Jiang, Yunguo, E-mail: jiangyg@ihep.ac.cn

On the basis of the quantum electrodynamics, we present a generic formalism of the polarization for beamed monochromatic photons scattered by electrons in any spectral distribution. The formulae reduce to the components of the Fano matrix when electrons are at rest. We mainly investigate the polarization in three scenarios, i.e., electrons at rest, isotropic electrons with a power-law spectrum, and thermal electrons. If the incident beam is polarized, the polarization is reduced significantly by isotropic electrons at large viewing angles; the degree of polarization caused by thermal electrons is about half of that caused by power-law electrons. If the incidentmore » bean is unpolarized, soft γ-rays can lead to about 15% polarization at viewing angles around π/4. For isotropic electrons, one remarkable feature is that the polarization as a function of the incident photon energy always peaks roughly at 1 MeV; this is valid for both the thermal and power-law cases. This feature can be used to distinguish the model of the inverse Compton scattering from that of the synchrotron radiation.« less

Photonic-powered cable assembly

DOEpatents

Sanderson, Stephen N.; Appel, Titus James; Wrye, IV, Walter C.

2013-01-22

A photonic-cable assembly includes a power source cable connector ("PSCC") coupled to a power receive cable connector ("PRCC") via a fiber cable. The PSCC electrically connects to a first electronic device and houses a photonic power source and an optical data transmitter. The fiber cable includes an optical transmit data path coupled to the optical data transmitter, an optical power path coupled to the photonic power source, and an optical feedback path coupled to provide feedback control to the photonic power source. The PRCC electrically connects to a second electronic device and houses an optical data receiver coupled to the optical transmit data path, a feedback controller coupled to the optical feedback path to control the photonic power source, and a photonic power converter coupled to the optical power path to convert photonic energy received over the optical power path to electrical energy to power components of the PRCC.

Photonic-powered cable assembly

DOEpatents

Sanderson, Stephen N; Appel, Titus James; Wrye, IV, Walter C

2014-06-24

A photonic-cable assembly includes a power source cable connector ("PSCC") coupled to a power receive cable connector ("PRCC") via a fiber cable. The PSCC electrically connects to a first electronic device and houses a photonic power source and an optical data transmitter. The fiber cable includes an optical transmit data path coupled to the optical data transmitter, an optical power path coupled to the photonic power source, and an optical feedback path coupled to provide feedback control to the photonic power source. The PRCC electrically connects to a second electronic device and houses an optical data receiver coupled to the optical transmit data path, a feedback controller coupled to the optical feedback path to control the photonic power source, and a photonic power converter coupled to the optical power path to convert photonic energy received over the optical power path to electrical energy to power components of the PRCC.

High Power Silicon Carbide (SiC) Power Processing Unit Development

NASA Technical Reports Server (NTRS)

Scheidegger, Robert J.; Santiago, Walter; Bozak, Karin E.; Pinero, Luis R.; Birchenough, Arthur G.

2015-01-01

NASA GRC successfully designed, built and tested a technology-push power processing unit for electric propulsion applications that utilizes high voltage silicon carbide (SiC) technology. The development specifically addresses the need for high power electronics to enable electric propulsion systems in the 100s of kilowatts. This unit demonstrated how high voltage combined with superior semiconductor components resulted in exceptional converter performance.

Energy-Focused Fusion Information System Integration, A NISE funded Capability Investment Project. Year 1 FY 2013 Report

DTIC Science & Technology

2013-09-01

major components, the power for the motor plus the power for operation dependent electronics. The power required for a disk operation can be...Love to Use", Novemeber 2009, Publicationof Juice , Inc. 4) Haves, Philip, "Building Modeling: EngergyPlus at Ames Research Center", May 2011, Brief

Lunar PMAD technology assessment

NASA Technical Reports Server (NTRS)

Metcalf, Kenneth J.

1992-01-01

This report documents an initial set of power conditioning models created to generate 'ballpark' power management and distribution (PMAD) component mass and size estimates. It contains converter, rectifier, inverter, transformer, remote bus isolator (RBI), and remote power controller (RPC) models. These models allow certain studies to be performed; however, additional models are required to assess a full range of PMAD alternatives. The intent is to eventually form a library of PMAD models that will allow system designers to evaluate various power system architectures and distribution techniques quickly and consistently. The models in this report are designed primarily for space exploration initiative (SEI) missions requiring continuous power and supporting manned operations. The mass estimates were developed by identifying the stages in a component and obtaining mass breakdowns for these stages from near term electronic hardware elements. Technology advances were then incorporated to generate hardware masses consistent with the 2000 to 2010 time period. The mass of a complete component is computed by algorithms that calculate the masses of the component stages, control and monitoring, enclosure, and thermal management subsystem.

Advanced Electrical Materials and Components Development: An Update

NASA Technical Reports Server (NTRS)

Schwarze, Gene E.

2005-01-01

The primary means to develop advanced electrical components is to develop new and improved materials for magnetic components (transformers, inductors, etc.), capacitors, and semiconductor switches and diodes. This paper will give an update of the Advanced Power Electronics and Components Technology being developed by the NASA Glenn Research Center for use in future Power Management and Distribution subsystems used in space power systems for spacecraft and lunar and planetary surface power. The initial description and status of this technology program was presented two years ago at the First International Energy Conversion Engineering Conference held at Portsmouth, Virginia, August 2003. The present paper will give a brief background of the previous work reported and a summary of research performed the past several years on soft magnetic materials characterization, dielectric materials and capacitor developments, high quality silicon carbide atomically smooth substrates, and SiC static and dynamic device characterization under elevated temperature conditions. The rationale for and the benefits of developing advanced electrical materials and components for the PMAD subsystem and also for the total power system will also be briefly discussed.

Experimental evidence of nonthermal acceleration of relativistic electrons by an intensive laser pulse

NASA Astrophysics Data System (ADS)

Kuramitsu, Y.; Nakanii, N.; Kondo, K.; Sakawa, Y.; Mori, Y.; Miura, E.; Tsuji, K.; Kimura, K.; Fukumochi, S.; Kashihara, M.; Tanimoto, T.; Nakamura, H.; Ishikura, T.; Takeda, K.; Tampo, M.; Kodama, R.; Kitagawa, Y.; Mima, K.; Tanaka, K. A.; Hoshino, M.; Takabe, H.

2011-02-01

Nonthermal acceleration of relativistic electrons is investigated with an intensive laser pulse. An energy distribution function of energetic particles in the universe or cosmic rays is well represented by a power-law spectrum, therefore, nonthermal acceleration is essential to understand the origin of cosmic rays. A possible candidate for the origin of cosmic rays is wakefield acceleration at relativistic astrophysical perpendicular shocks. The wakefield is considered to be excited by large-amplitude precursor light waves in the upstream of the shocks. Substituting an intensive laser pulse for the large amplitude light waves, we performed a model experiment of the shock environments in a laboratory plasma. An intensive laser pulse was propagated in a plasma tube created by imploding a hollow polystyrene cylinder, as the large amplitude light waves propagated in the upstream plasma at an astrophysical shock. Nonthermal electrons were generated, and the energy distribution functions of the electrons have a power-law component with an index of ~2. We described the detailed procedures to obtain the nonthermal components from data obtained by an electron spectrometer.

Energy balance in TM-1-MH Tokamak (ohmical heating)

NASA Astrophysics Data System (ADS)

Stoeckel, J.; Koerbel, S.; Kryska, L.; Kopecky, V.; Dadalec, V.; Datlov, J.; Jakubka, K.; Magula, P.; Zacek, F.; Pereverzev, G. V.

1981-10-01

Plasma in the TM-1-MH Tokamak was experimentally studied in the parameter range: tor. mg. field B = 1,3 T, plasma current I sub p = 14 kA, electron density N sub E 3.10 to the 19th power cubic meters. The two numerical codes are available for the comparison with experimental data. TOKATA-code solves simplified energy balance equations for electron and ion components. TOKSAS-code solves the detailed energy balance of the ion component.

First NuSTAR observations of the BL Lac - type blazar PKS 2155-304: constraints on the jet content and distribution of radiating particles

NASA Astrophysics Data System (ADS)

Madejski, Grzegorz; Nalewajko, Krzysztof; Madsen, Kristin; Chiang, James; Balokovic, Mislav; Paneque, David; Furniss, Amy; NuSTAR Team

2017-01-01

Current scenarios for emission mechanisms operating in relativistic jets in AGN involve synchrotron emission for the radio through UV spectrum, and inverse Compton for hard X-rays through γ-rays, but the particle content of relativistic jets - whether they are dominated by proton-electron, or e +/e- plasma - has not been established. Our first hard X-ray observations with NuSTAR of the BL Lac type blazar PKS 2155-304, augmented by XMM-Newton data, reveal the 0.5-60 keV spectrum as best-described by a soft power law component dominating below 10 keV (photon index of 3 at 2 keV), and a hard power-law tail (index 2), dominating in the 20-60 keV range. The hard X-ray tail can be smoothly joined to the quasi-simultaneous Fermi/LAT γ-ray spectrum by a synchrotron self-Compton component produced by an electron distribution with index p =2.2. The jet content needs to (globally) obey charge neutrality; assuming that the power-law electron distribution extends down to the Lorentz factor of 1, and one proton per electron, yields an unrealistically high total jet power of 1047 erg/s. This can be reduced by two orders of magnitude by considering a significant presence of e +/e- pairs with lepton-to-proton ratio of at least 30.

Advanced Data Acquisition Systems

NASA Technical Reports Server (NTRS)

Perotti, J.

2003-01-01

Current and future requirements of the aerospace sensors and transducers field make it necessary for the design and development of new data acquisition devices and instrumentation systems. New designs are sought to incorporate self-health, self-calibrating, self-repair capabilities, allowing greater measurement reliability and extended calibration cycles. With the addition of power management schemes, state-of-the-art data acquisition systems allow data to be processed and presented to the users with increased efficiency and accuracy. The design architecture presented in this paper displays an innovative approach to data acquisition systems. The design incorporates: electronic health self-check, device/system self-calibration, electronics and function self-repair, failure detection and prediction, and power management (reduced power consumption). These requirements are driven by the aerospace industry need to reduce operations and maintenance costs, to accelerate processing time and to provide reliable hardware with minimum costs. The project's design architecture incorporates some commercially available components identified during the market research investigation like: Field Programmable Gate Arrays (FPGA) Programmable Analog Integrated Circuits (PAC IC) and Field Programmable Analog Arrays (FPAA); Digital Signal Processing (DSP) electronic/system control and investigation of specific characteristics found in technologies like: Electronic Component Mean Time Between Failure (MTBF); and Radiation Hardened Component Availability. There are three main sections discussed in the design architecture presented in this document. They are the following: (a) Analog Signal Module Section, (b) Digital Signal/Control Module Section and (c) Power Management Module Section. These sections are discussed in detail in the following pages. This approach to data acquisition systems has resulted in the assignment of patent rights to Kennedy Space Center under U.S. patent # 6,462,684. Furthermore, NASA KSC commercialization office has issued licensing rights to Circuit Avenue Netrepreneurs, LLC , a minority-owned business founded in 1999 located in Camden, NJ.

Modelling and Simulation of Grid Connected SPV System with Active Power Filtering Features

NASA Astrophysics Data System (ADS)

Saroha, Jaipal; Pandove, Gitanjali; Singh, Mukhtiar

2017-09-01

In this paper, the detailed simulation studies for a grid connected solar photovoltaic system (SPV) have been presented. The power electronics devices like DC-DC boost converter and grid interfacing inverter are most important components of proposed system. Here, the DC-DC boost converter is controlled to extract maximum power out of SPV under different irradiation levels, while the grid interfacing inverter is utilized to evacuate the active power and feed it into grid at synchronized voltage and frequency. Moreover, the grid interfacing inverter is also controlled to sort out the issues related to power quality by compensating the reactive power and harmonics current component of nearby load at point of common coupling. Besides, detailed modeling of various component utilized in proposed system is also presented. Finally, extensive simulations have been performed under different irradiation levels with various kinds of load to validate the aforementioned claims. The overall system design and simulation have been performed by using Sim Power System toolbox available in the library of MATLAB.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moreno, Gilbert

The objective for this project is to develop thermal management strategies to enable efficient and high-temperature wide-bandgap (WBG)-based power electronic systems (e.g., emerging inverter and DC-DC converter). Device- and system-level thermal analyses are conducted to determine the thermal limitations of current automotive power modules under elevated device temperature conditions. Additionally, novel cooling concepts and material selection will be evaluated to enable high-temperature silicon and WBG devices in power electronics components. WBG devices (silicon carbide [SiC], gallium nitride [GaN]) promise to increase efficiency, but will be driven as hard as possible. This creates challenges for thermal management and reliability.

Test facility for the evaluation of microwave transmission components

NASA Astrophysics Data System (ADS)

Fong, C. G.; Poole, B. R.

1985-10-01

A Low Power Test Facility (LPTF) was developed to evaluate the performance of Electron Cyclotron Resonance Heating (ECRH) microwave transmission components for the Mirror Fusion Test Facility (MFTF-B). The facility generates 26 to 60 GHz in modes of TE01, TE02, or TE03 launched at power levels of 1/2 milliwatt. The propagation of the RF as it radiates from either transmitting or secondary reflecting microwave transmission components is recorded by a discriminating crystal detector mechanically manipulated at constant radius in spherical coordinates. The facility is used to test, calibrate, and verify the design of overmoded, circular waveguide components, quasi-optical reflecting elements before high power use. The test facility consists of microwave sources and metering components, such as VSWR, power and frequency meters, a rectangular TE10 to circular TE01 mode transducer, mode filter, circular TE01 to 2.5 in. diameter overmoded waveguide with mode converters for combination of TE01 to TE03 modes. This assembly then connects to a circular waveguide launcher or the waveguide component under test.

FY2013 Advanced Power Electronics and Electric Motors R&D Annual Progress Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rogers, Susan A.

The Advanced Power Electronics and Electric Motors (APEEM) technology area within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on developing revolutionary new power electronics (PE), electric motor, and traction drive system (TDS) technologies that will leapfrog current on-the-road technologies, leading to lower cost and better efficiency in transforming battery energy to useful work. The research and development (R&D) is also aimed at achieving a greater understanding of and improvements in the way the various new components of tomorrow’s automobiles will function as a unified system tomore » improve fuel efficiency through research in more efficient TDSs.« less

Compact self-powered synchronous energy extraction circuit design with enhanced performance

NASA Astrophysics Data System (ADS)

Liu, Weiqun; Zhao, Caiyou; Badel, Adrien; Formosa, Fabien; Zhu, Qiao; Hu, Guangdi

2018-04-01

Synchronous switching circuit is viewed as an effective solution of enhancing the generator’s performance and providing better adaptability for load variations. A critical issue for these synchronous switching circuits is the self-powered realization. In contrast with other methods, the electronic breaker possesses the advantage of simplicity and reliability. However, beside the energy consumption of the electronic breakers, the parasitic capacitance decreases the available piezoelectric voltage. In this technical note, a new compact design of the self-powered switching circuit using electronic breaker is proposed. The envelope diodes are excluded and only a single envelope capacitor is used. The parasitic capacitance is reduced to half with boosted performance while the components are reduced with cost saved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moreno, Gilbert; Bennion, Kevin

This project will develop thermal management strategies to enable efficient and high-temperature wide-bandgap (WBG)-based power electronic systems (e.g., emerging inverter and DC-DC converter designs). The use of WBG-based devices in automotive power electronics will improve efficiency and increase driving range in electric-drive vehicles; however, the implementation of this technology is limited, in part, due to thermal issues. This project will develop system-level thermal models to determine the thermal limitations of current automotive power modules under elevated device temperature conditions. Additionally, novel cooling concepts and material selection will be evaluated to enable high-temperature silicon and WBG devices in power electronics components.more » WBG devices (silicon carbide [SiC], gallium nitride [GaN]) promise to increase efficiency, but will be driven as hard as possible. This creates challenges for thermal management and reliability.« less

Development and study of aluminum-air electrochemical generator and its main components

NASA Astrophysics Data System (ADS)

Ilyukhina, A. V.; Kleymenov, B. V.; Zhuk, A. Z.

2017-02-01

Aluminum-air power sources are receiving increased attention for applications in portable electronic devices, transportation, and energy systems. This study reports on the development of an aluminum-air electrochemical generator (AA ECG) and provides a technical foundation for the selection of its components, i.e., aluminum anode, gas diffusion cathode, and alkaline electrolyte. A prototype 1.5 kW AA ECG with specific energy of 270 Wh kg-1 is built and tested. The results of this study demonstrate the feasibility of AA ECGs as portable reserve and emergency power sources, as well as power sources for electric vehicles.

Development of a dual-field heteropoplar power converter

NASA Technical Reports Server (NTRS)

Eisenhaure, D. B.; Johnson, B.; Bliamptis, T.; St. George, E.

1981-01-01

The design and testing of a 400 watt, dual phase, dual rotor, field modulated inductor alternator is described. The system is designed for use as a flywheel to ac utility line or flywheel to dc bus (electric vehicle) power converter. The machine is unique in that it uses dual rotors and separately controlled fields to produce output current and voltage which are in phase with each other. Having the voltage and current in phase allows the power electronics to be made of simple low cost components. Based on analytical predictions and experimental results, development of a complete 22 kilowatt (30 Hp) power conversion system is recommended. This system would include power electronics and controls and would replace the inductor alternator with an improved electromagnetic conversion system.

Research on Nitride Thin Films, Advanced Plasma Diagnostics, and Charged-Particle Processes

DTIC Science & Technology

2006-07-01

Additionally, these components are being placed closer to the point of use--requiring that they operate in extreme temperature environments ...reasons for component failure. To operate in extreme temperature environments , electronic and electrical components must withstand higher ambient...hybrid and plug-in hybrid-powered automobiles, heart defibrillators , and industrial equipment will benefit from a new generation of capacitors. High

Parallel Optical Random Access Memory (PORAM)

NASA Technical Reports Server (NTRS)

Alphonse, G. A.

1989-01-01

It is shown that the need to minimize component count, power and size, and to maximize packing density require a parallel optical random access memory to be designed in a two-level hierarchy: a modular level and an interconnect level. Three module designs are proposed, in the order of research and development requirements. The first uses state-of-the-art components, including individually addressed laser diode arrays, acousto-optic (AO) deflectors and magneto-optic (MO) storage medium, aimed at moderate size, moderate power, and high packing density. The next design level uses an electron-trapping (ET) medium to reduce optical power requirements. The third design uses a beam-steering grating surface emitter (GSE) array to reduce size further and minimize the number of components.

FY2007 Oak Ridge National Laboratory Annual Progress Report for the Power Electronics and Electric Machinery Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszewski, Mitchell

The U.S. Department of Energy (DOE) and the U.S. Council for Automotive Research (composed of automakers Ford, General Motors, and Chrysler) announced in January 2002 a new cooperative research effort. Known as 'FreedomCAR' (derived from 'Freedom' and 'Cooperative Automotive Research'), it represents DOE's commitment to developing public/private partnerships to fund high-risk, high-payoff research into advanced automotive technologies. Efficient fuel cell technology, which uses hydrogen to power automobiles without air pollution, is a very promising pathway to achieving the ultimate vision. The new partnership replaces and builds upon the Partnership for a New Generation of Vehicles initiative that ran from 1993more » through 2001. The Advanced Power Electronics and Electric Machines (APEEM) subprogram within the FreedomCAR and Vehicle Technologies Program provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on understanding and improving the way the various new components of tomorrow's automobiles will function as a unified system to improve fuel efficiency. In supporting the development of hybrid propulsion systems, the APEEM effort has enabled the development of technologies that will significantly improve advanced vehicle efficiency, costs, and fuel economy. The APEEM subprogram supports the efforts of the FreedomCAR and Fuel Partnership through a three-phase approach intended to: (1) identify overall propulsion and vehicle-related needs by analyzing programmatic goals and reviewing industry's recommendations and requirements and then develop the appropriate technical targets for systems, subsystems, and component research and development activities; (2) develop and validate individual subsystems and components, including electric motors and power electronics; and (3) determine how well the components and subsystems work together in a vehicle environment or as a complete propulsion system and whether the efficiency and performance targets at the vehicle level have been achieved. The research performed under this subprogram will help remove technical and cost barriers to enable the development of technology for use in such advanced vehicles as hybrid and fuel-cell-powered automobiles that meet the goals of the FreedomCAR and Vehicle Technologies Program. A key element in making hybrid electric vehicles (HEVs) practical is providing an affordable electric traction drive system. This will require attaining weight, volume, and cost targets for the power electronics and electrical machines subsystems of the traction drive system. Areas of development include these: (1) novel traction motor designs that result in increased power density and lower cost; (2) inverter technologies involving new topologies to achieve higher efficiency and the ability to accommodate higher-temperature environments; (3) converter concepts that employ means of reducing the component count and integrating functionality to decrease size, weight, and cost; (4) more effective thermal control and packaging technologies; and (5) integrated motor/inverter concepts. The Oak Ridge National Laboratory's (ORNL's) Power Electronics and Electric Machinery Research Center conducts fundamental research, evaluates hardware, and assists in the technical direction of the DOE Office of FreedomCAR and Vehicle Technologies Program, APEEM subprogram. In this role, ORNL serves on the FreedomCAR Electrical and Electronics Technical Team, evaluates proposals for DOE, and lends its technological expertise to the direction of projects and evaluation of developing technologies. ORNL also executes specific projects for DOE. The following report discusses those projects carried out in FY 2007 and conveys highlights of their accomplishments. Numerous project reviews, technical reports, and papers have been published for these efforts, if the reader is interested in pursuing details of the work.« less

Fixation of operating point and measurement of turn on characteristics of IGBT F4-75R06W1E3

NASA Astrophysics Data System (ADS)

Haseena, A.; Subhash Joshi T., G.; George, Saly

2018-05-01

For the proficient operation of the Power electronic circuit, signal level performance of power electronic devices are very important. For getting good signal level characteristics, fixing operating point is very critical. Device deviates from the typical characteristics given in the datasheet due to the presence of stray components in the circuit lay out. Fixation of operating point of typical silicon IGBT and its turn on characteristics is discussed in this paper.

Photonic Integrated Circuits

NASA Technical Reports Server (NTRS)

Krainak, Michael; Merritt, Scott

2016-01-01

Integrated photonics generally is the integration of multiple lithographically defined photonic and electronic components and devices (e.g. lasers, detectors, waveguides passive structures, modulators, electronic control and optical interconnects) on a single platform with nanometer-scale feature sizes. The development of photonic integrated circuits permits size, weight, power and cost reductions for spacecraft microprocessors, optical communication, processor buses, advanced data processing, and integrated optic science instrument optical systems, subsystems and components. This is particularly critical for small spacecraft platforms. We will give an overview of some NASA applications for integrated photonics.

Developing a 300C Analog Tool for EGS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Normann, Randy

2015-03-23

This paper covers the development of a 300°C geothermal well monitoring tool for supporting future EGS (enhanced geothermal systems) power production. This is the first of 3 tools planed. This is an analog tool designed for monitoring well pressure and temperature. There is discussion on 3 different circuit topologies and the development of the supporting surface electronics and software. There is information on testing electronic circuits and component. One of the major components is the cable used to connect the analog tool to the surface.

Highest integration in microelectronics: Development of digital ASICs for PARS3-LR

NASA Astrophysics Data System (ADS)

Scholler, Peter; Vonlutz, Rainer

Essential electronic system components by PARS3-LR, show high requirements in calculation power, power consumption and reliability, by immediately increasing integration thicknesses. These problems are solved by using integrated circuits, developed by LSI LOGIC, that uses the technical and economic advantages of this leading edge technology.

Cooling Concepts for High Power Density Magnetic Devices

NASA Astrophysics Data System (ADS)

Biela, Juergen; Kolar, Johann W.

In the area or power electronics there is a general trend to higher power densities. In order to increase the power density the systems must be designed optimally concerning topology, semiconductor selection, etc. and the volume of the components must be decreased. The decreasing volume comes along with a reduced surface for cooling. Consequently, new cooling methods are required. In the paper an indirect air cooling system for magnetic devices which combines the transformer with a heat sink and a heat transfer component is presented. Moreover, an analytic approach for calculating the temperature distribution is derived and validated by measurements. Based on these equations a transformer with an indirect air cooling system is designed for a 10kW telecom power supply.

Microfabricated thermoelectric power-generation devices

NASA Technical Reports Server (NTRS)

Fleurial, Jean-Pierre (Inventor); Phillips, Wayne (Inventor); Borshchevsky, Alex (Inventor); Kolawa, Elizabeth A. (Inventor); Ryan, Margaret A. (Inventor); Caillat, Thierry (Inventor); Mueller, Peter (Inventor); Snyder, G. Jeffrey (Inventor); Kascich, Thorsten (Inventor)

2002-01-01

A device for generating power to run an electronic component. The device includes a heat-conducting substrate (composed, e.g., of diamond or another high thermal conductivity material) disposed in thermal contact with a high temperature region. During operation, heat flows from the high temperature region into the heat-conducting substrate, from which the heat flows into the electrical power generator. A thermoelectric material (e.g., a BiTe alloy-based film or other thermoelectric material) is placed in thermal contact with the heat-conducting substrate. A low temperature region is located on the side of the thermoelectric material opposite that of the high temperature region. The thermal gradient generates electrical power and drives an electrical component.

Microfabricated thermoelectric power-generation devices

NASA Technical Reports Server (NTRS)

Fleurial, Jean-Pierre (Inventor); Ryan, Margaret A. (Inventor); Borshchevsky, Alex (Inventor); Phillips, Wayne (Inventor); Kolawa, Elizabeth A. (Inventor); Snyder, G. Jeffrey (Inventor); Caillat, Thierry (Inventor); Kascich, Thorsten (Inventor); Mueller, Peter (Inventor)

2004-01-01

A device for generating power to run an electronic component. The device includes a heat-conducting substrate (composed, e.g., of diamond or another high thermal conductivity material) disposed in thermal contact with a high temperature region. During operation, heat flows from the high temperature region into the heat-conducting substrate, from which the heat flows into the electrical power generator. A thermoelectric material (e.g., a BiTe alloy-based film or other thermoelectric material) is placed in thermal contact with the heat-conducting substrate. A low temperature region is located on the side of the thermoelectric material opposite that of the high temperature region. The thermal gradient generates electrical power and drives an electrical component.

Rocket observations at the northern edge of the eastward electrojet

NASA Technical Reports Server (NTRS)

Cahill, L. J., Jr.; Arnoldy, R. L.; Taylor, W. W. L.

1980-01-01

The paper discusses a Nike-Tomahawk rocket launched north over quiet, late evening auroral arcs in March 1975. A northward magnetic disturbance was observed on the ground under the rocket trajectory; south of the arcs the northward electric field was 60 mV/m, indicating strong westward plasma flow. An eastward electrojet current layer was penetrated in the upward flight, and precipitating electrons were observed over each arc. Using the observed electron flux and a model of the ionosphere, the Hall and Pedersen conductivities were calculated which were used to compute the eastward and northward components of the horizontal ionospheric currents. The joule power decreased abruptly in the auroral arcs, as the precipitating electron power increased; the total dissipated power was the same inside the arcs, between them and southward. North of the aurora the electric field and dissipated power remained low; field-aligned currents carried by the observed electrons were about a factor of 3 lower than those inferred from the magnetic field measurements.

Developing a stability assessment method for power electronics-based microgrids

NASA Astrophysics Data System (ADS)

Austin, Peter M.

Modern microgrids with microsources and energy storage are dependent on power electronics for control and regulation. Under certain circumstances power electronics can be destabilizing to the system due to an effect called negative incremental impedance. A careful review of the theory and literature on the subject is presented. This includes stability criteria for both AC and DC systems, as well as a discussion on the limitations posed by the analysis. A method to integrate stability assessment with higher-level microgrid architectural design is proposed. Crucial to this is impedance characterization of individual components, which was accomplished through simulation. DC and AC impedance measurement blocks were created in Matlab simulink to automate the process. A detailed switching-level model of a DC microgrid was implemented in simulink, including wind turbine microsource, battery storage, and three phase inverter. Maximum power point tracking (MPPT) was included to maximize the efficiency of the turbine and was implemented through three rectifier alternatives and control schemes. The stability characteristics of each was compared in the final analysis. Impedance data was collected individually from the components and used to assess stability in the system as a whole. The results included the assessment of stability, margin, and unstable operating points to demonstrate the feasibility of the proposed approach.

Study of RF breakdown and multipacting in accelerator components

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pande, Manjiri; Singh, P., E-mail: manjiri@barc.gov.in, E-mail: psingh@barc.gov.in

2014-07-01

Radio frequency (RF) structures that are part of accelerators and energy sources, operate with sinusoidally varying electromagnetic fields under high RF energy. Here, RF breakdown and multipacting take place in RF structures and limit their performance. Electron field emission processes in a RF structure are precursors for breakdown processes. RF breakdown is a major phenomena affecting and causing the irreversible damage to RF structures. Breakdown rate and the damage induced by the breakdowns are its important properties. The damage is related to power absorbed during breakdown, while the breakdown rate is determined by the amplitudes of surface electric and magneticmore » fields, geometry, metal surface preparation and conditioning history. It limits working power and produces irreversible surface damage. The breakdown limit depends on the RF circuit, structure geometry, RF frequency, input RF power, pulse width, materials used, surface processing technique and surface electric and magnetic fields. Multipactor (MP) is a low power, electron multiplication based resonance breakdown phenomenon in vacuum and is often observed in RF structures. A multipactor discharge is undesirable, as it can create a reactive component that detunes the resonant cavities and components, generates noise in communication system and induces gas desorption from the conductor surfaces. In RF structures, certain conditions are required to generate multipacting. (author)« less

USSR and Eastern Europe Scientific Abstracts, Electronics and Electrical Engineering, Number 27

DTIC Science & Technology

1977-02-10

input and output conditions. The power section of the circuit is modified to permit triacs and thyristors, respectively, to function. The purpose of the...electronic materials, components, and devices, on circuit theory, pulse techniques, electromagnetic wave propagation, radar, quantum electronic theory...Lasers, Masers, Holography, Quasi-Optical 20 Microelectronics and General Circuit Theory and Information 21 Radars and Radio Wavigati on 22

Germany Briefing

DTIC Science & Technology

2011-07-27

Ion Battery Packs Advanced Chemistry Batteries EM Armor Power Brick 8 UNCLASSIFIED Concepts Platform Simulation Component Development Vehicle...Advanced Turbocharging, Supercharging, OPOC Efficient Powertrain Technologies Electrified Accessories Energy Harvesting SiC Electronics Lithium

Actively controlling coolant-cooled cold plate configuration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chainer, Timothy J.; Parida, Pritish R.

A method is provided to facilitate active control of thermal and fluid dynamic performance of a coolant-cooled cold plate. The method includes: monitoring a variable associated with at least one of the coolant-cooled cold plate or one or more electronic components being cooled by the cold plate; and dynamically varying, based on the monitored variable, a physical configuration of the cold plate. By dynamically varying the physical configuration, the thermal and fluid dynamic performance of the cold plate are adjusted to, for example, optimally cool the one or more electronic components, and at the same time, reduce cooling power consumptionmore » used in cooling the electronic component(s). The physical configuration can be adjusted by providing one or more adjustable plates within the coolant-cooled cold plate, the positioning of which may be adjusted based on the monitored variable.« less

High temperature electronics applications in space exploration

NASA Technical Reports Server (NTRS)

Jurgens, R. F.

1981-01-01

The extension of the range of operating temperatures of electronic components and systems for planetary exploration is examined. In particular, missions which utilize balloon-borne instruments to study the Venusian and Jovian atmospheres are discussed. Semiconductor development and devices including power sources, ultrastable oscillators, transmitters, antennas, electromechanical devices, and deployment systems are addressed.

Collective Thomson scattering of a high power electron cyclotron resonance heating beam in LHD (invited).

PubMed

Kubo, S; Nishiura, M; Tanaka, K; Shimozuma, T; Yoshimura, Y; Igami, H; Takahash, H; Mutoh, T; Tamura, N; Tatematsu, Y; Saito, T; Notake, T; Korsholm, S B; Meo, F; Nielsen, S K; Salewski, M; Stejner, M

2010-10-01

Collective Thomson scattering (CTS) system has been constructed at LHD making use of the high power electron cyclotron resonance heating (ECRH) system in Large Helical Device (LHD). The necessary features for CTS, high power probing beams and receiving beams, both with well defined Gaussian profile and with the fine controllability, are endowed in the ECRH system. The 32 channel radiometer with sharp notch filter at the front end is attached to the ECRH system transmission line as a CTS receiver. The validation of the CTS signal is performed by scanning the scattering volume. A new method to separate the CTS signal from background electron cyclotron emission is developed and applied to derive the bulk and high energy ion components for several combinations of neutral beam heated plasmas.

Next Generation Inverter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Zilai; Gough, Charles

The goal of this Cooperative Agreement was the development of a Next Generation Inverter for General Motors’ electrified vehicles, including battery electric vehicles, range extended electric vehicles, plug-in hybrid electric vehicles and hybrid electric vehicles. The inverter is a critical electronics component that converts battery power (DC) to and from the electric power for the motor (AC).

The modeling of a standalone solid-oxide fuel cell auxiliary power unit

NASA Astrophysics Data System (ADS)

Lu, N.; Li, Q.; Sun, X.; Khaleel, M. A.

In this research, a Simulink model of a standalone vehicular solid-oxide fuel cell (SOFC) auxiliary power unit (APU) is developed. The SOFC APU model consists of three major components: a controller model; a power electronics system model; and an SOFC plant model, including an SOFC stack module, two heat exchanger modules, and a combustor module. This paper discusses the development of the nonlinear dynamic models for the SOFC stacks, the heat exchangers and the combustors. When coupling with a controller model and a power electronic circuit model, the developed SOFC plant model is able to model the thermal dynamics and the electrochemical dynamics inside the SOFC APU components, as well as the transient responses to the electric loading changes. It has been shown that having such a model for the SOFC APU will help design engineers to adjust design parameters to optimize the performance. The modeling results of the SOFC APU heat-up stage and the output voltage response to a sudden load change are presented in this paper. The fuel flow regulation based on fuel utilization is also briefly discussed.

A gamma-ray burst with a high-energy spectral component inconsistent with the synchrotron shock model.

PubMed

González, M M; Dingus, B L; Kaneko, Y; Preece, R D; Dermer, C D; Briggs, M S

2003-08-14

Gamma-ray bursts are among the most powerful events in nature. These events release most of their energy as photons with energies in the range from 30 keV to a few MeV, with a smaller fraction of the energy radiated in radio, optical, and soft X-ray afterglows. The data are in general agreement with a relativistic shock model, where the prompt and afterglow emissions correspond to synchrotron radiation from shock-accelerated electrons. Here we report an observation of a high-energy (multi-MeV) spectral component in the burst of 17 October 1994 that is distinct from the previously observed lower-energy gamma-ray component. The flux of the high-energy component decays more slowly and its fluence is greater than the lower-energy component; it is described by a power law of differential photon number index approximately -1 up to about 200 MeV. This observation is difficult to explain with the standard synchrotron shock model, suggesting the presence of new phenomena such as a different non-thermal electron process, or the interaction of relativistic protons with photons at the source.

High bandwidth magnetically isolated signal transmission circuit

NASA Technical Reports Server (NTRS)

Repp, John Donald (Inventor)

2005-01-01

Many current electronic systems incorporate expensive or sensitive electrical components. Because electrical energy is often generated or transmitted at high voltages, the power supplies to these electronic systems must be carefully designed. Power supply design must ensure that the electrical system being supplied with power is not exposed to excessive voltages or currents. In order to isolate power supplies from electrical equipment, many methods have been employed. These methods typically involve control systems or signal transfer methods. However, these methods are not always suitable because of their drawbacks. The present invention relates to transmitting information across an interface. More specifically, the present invention provides an apparatus for transmitting both AC and DC information across a high bandwidth magnetic interface with low distortion.

Low power signal processing electronics for wearable medical devices.

PubMed

Casson, Alexander J; Rodriguez-Villegas, Esther

2010-01-01

Custom designed microchips, known as Application Specific Integrated Circuits (ASICs), offer the lowest possible power consumption electronics. However, this comes at the cost of a longer, more complex and more costly design process compared to one using generic, off-the-shelf components. Nevertheless, their use is essential in future truly wearable medical devices that must operate for long periods of time from physically small, energy limited batteries. This presentation will demonstrate the state-of-the-art in ASIC technology for providing online signal processing for use in these wearable medical devices.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waye, Scot

Power electronics that use high-temperature devices pose a challenge for thermal management. With the devices running at higher temperatures and having a smaller footprint, the heat fluxes increase from previous power electronic designs. This project overview presents an approach to examine and design thermal management strategies through cooling technologies to keep devices within temperature limits, dissipate the heat generated by the devices and protect electrical interconnects and other components for inverter, converter, and charger applications. This analysis, validation, and demonstration intends to take a multi-scale approach over the device, module, and system levels to reduce size, weight, and cost.

System for Cooling of Electronic Components

NASA Astrophysics Data System (ADS)

Vasil'ev, L. L.; Grakovich, L. P.; Dragun, L. A.; Zhuravlev, A. S.; Olekhnovich, V. A.; Rabetskii, M. I.

2017-01-01

Results of computational and experimental investigations of heat pipes having a predetermined thermal resistance and a system based on these pipes for air cooling of electronic components and diode assemblies of lasers are presented. An efficient compact cooling system comprising heat pipes with an evaporator having a capillary coating of a caked copper powder and a condenser having a developed outer finning, has been deviced. This system makes it possible to remove, to the ambient air, a heat flow of power more than 300 W at a temperature of 40-50°C.

Component Repair Experiment-1: An Experiment Evaluating Electronic Component-Level Repair During Spaceflight

NASA Technical Reports Server (NTRS)

Easton, John W.; Struk, Peter M.

2012-01-01

The Component Repair Experiment-1 (CRE-1) examines the capability for astronauts to perform electronics repair tasks in space. The goal is to determine the current capabilities and limits for the crew, and to make recommendations to improve and expand the range of work that astronauts may perform. CRE-1 provided two-layer, functional circuit boards and replacement components, a small tool kit, written and video training materials, and 1 hr of hands on training for the crew slated to perform the experiment approximately 7 months prior to the mission. Astronauts Michael Fincke and Sandra Magnus performed the work aboard the International Space Station (ISS) in February and March 2009. The astronauts were able to remove and replace components successfully, demonstrating the feasibility of performing component-level electronics repairs within a spacecraft. Several unsuccessful tasks demonstrated areas in need of improvement. These include improved and longer training prior to a mission, an improved soldering iron with a higher operating temperature and steady power source, video training and practice boards for refresher work or practice before a repair, and improved and varied hand tools and containment system.

NASA Tech Briefs, August 1995. Volume 19, No. 8

NASA Technical Reports Server (NTRS)

1995-01-01

There is a special focus on computer graphics and simulation in this issue. Topics covered include : Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer programs, Mechanics; Machinery; Fabrication Technology; and Mathematics and Information Sciences. There is a section on for Laser Technology, which includes a feature on Moving closer to the suns power.

Checker Takes the Guesswork out of Diode Identification

ERIC Educational Resources Information Center

Harman, Charles

2011-01-01

At technical colleges and secondary-level tech schools, students enrolled in basic electronics labs who have learned about diodes that do rectification are used to seeing power diodes like the 1N4001. When the students are introduced to low-power zener diodes and signal diodes, component identification gets more complex. If the small zeners are…

High resolution IVEM tomography of biological specimens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sedat, J.W.; Agard, D.A.

Electron tomography is a powerful tool for elucidating the three-dimensional architecture of large biological complexes and subcellular organelles. The introduction of intermediate voltage electron microscopes further extended the technique by providing the means to examine very large and non-symmetrical subcellular organelles, at resolutions beyond what would be possible using light microscopy. Recent studies using electron tomography on a variety of cellular organelles and assemblies such as centrosomes, kinetochores, and chromatin have clearly demonstrated the power of this technique for obtaining 3D structural information on non-symmetric cell components. When combined with biochemical and molecular observations, these 3D reconstructions have provided significantmore » new insights into biological function.« less

Embedded electronics for intelligent structures

NASA Astrophysics Data System (ADS)

Warkentin, David J.; Crawley, Edward F.

The signal, power, and communications provisions for the distributed control processing, sensing, and actuation of an intelligent structure could benefit from a method of physically embedding some electronic components. The preliminary feasibility of embedding electronic components in load-bearing intelligent composite structures is addressed. A technique for embedding integrated circuits on silicon chips within graphite/epoxy composite structures is presented which addresses the problems of electrical, mechanical, and chemical isolation. The mechanical and chemical isolation of test articles manufactured by this technique are tested by subjecting them to static and cyclic mechanical loads and a temperature/humidity/bias environment. The likely failure modes under these conditions are identified, and suggestions for further improvements in the technique are discussed.

Novel concept for driving the linear compressor of a micro-miniature split Stirling cryogenic cooler

NASA Astrophysics Data System (ADS)

Maron, V.; Veprik, A.; Finkelstein, L.; Vilenchik, H.; Ziv, I.; Pundak, N.

2009-05-01

New methods of carrying out homeland security and antiterrorist operations call for the development of a new generation of mechanically cooled, portable, battery powered infrared imagers, relying on micro-miniature Stirling cryogenic coolers of rotary or linear types. Since split Stirling linearly driven micro-miniature cryogenic coolers have inherently longer life spans, low vibration export and better aural stealth as compared to their rotary driven rivals, they are more suitable for the above applications. The performance of such cryogenic coolers depends strongly on the efficacy of their electronic drivers. In a traditional approach, the PWM power electronics produce the fixed frequency tonal driving voltage/current, the magnitude of which is modulated via a PID control law so as to maintain the desired focal plane array temperature. The disadvantage of such drivers is that they draw high ripple current from the system's power bus. This results in the need for an oversized DC power supply (battery packs) and power electronic components, low efficiency due to excessive conductive losses and high residual electromagnetic interference which in turn degrades the performance of other systems connected to the same power bus. Without either an active line filter or large and heavy passive filtering, other electronics can not be powered from the same power bus, unless they incorporate heavy filtering at their inputs. The authors present the results of a feasibility study towards developing a novel "pumping" driver consuming essentially constant instant battery power/current without making use of an active or passive filter. In the tested setup, the driver relies on a bidirectional controllable bridge, invertible with the driving frequency, and a fast regulated DC/DC converter which maintains a constant level of current consumed from the DC power supply and thus operates in input current control mode. From the experimental results, the steady-state power consumed by the linear compressor remains the same as compared with the traditional sine wave driver, the voltage and current drawn from the battery pack is essentially free of low frequency ripple (this without use of any kind of filtering) and the overall coefficient of performance of the driver is in excess of 94% over the entire working range of supply voltages. Such a driver free of sine forming PWM stage and have reduced power peaks in all power conversion components.

Turbulent Equilibria for Charged Particles in Space

NASA Astrophysics Data System (ADS)

Yoon, Peter

2017-04-01

The solar wind electron distribution function is apparently composed of several components including non-thermal tail population. The electron distribution that contains energetic tail feature is well fitted with the kappa distribution function. The solar wind protons also possess quasi power-law tail distribution function that is well fitted with an inverse power law model. The present paper discusses the latest theoretical development regarding the dynamical steady-state solution of electrons and Langmuir turbulence that are in turbulent equilibrium. According to such a theory, the Maxwellian and kappa distribution functions for the electrons emerge as the only two possible solution that satisfy the steady-state weak turbulence plasma kinetic equation. For the proton inverse power-law tail problem, a similar turbulent equilibrium solution can be conceived of, but instead of high-frequency Langmuir fluctuation, the theory involves low-frequency kinetic Alfvenic turbulence. The steady-state solution of the self-consistent proton kinetic equation and wave kinetic equation for Alfvenic waves can be found in order to obtain a self-consistent solution for the inverse power law tail distribution function.

Electronic Components and Systems for Cryogenic Space Applications

NASA Technical Reports Server (NTRS)

Patterson, R. L.; Hammoud, A.; Dickman, J. E.; Gerber, S.; Elbuluk, M. E.; Overton, E.

2001-01-01

Electronic components and systems capable of operation at cryogenic temperatures are anticipated in many future NASA space missions such as deep space probes and planetary surface exploration. For example, an unheated interplanetary probe launched to explore the rings of Saturn would reach an average temperature near Saturn of about - 183 C. In addition to surviving the deep space harsh environment, electronics capable of low temperature operation would contribute to improving circuit performance, increasing system efficiency, and reducing payload development and launch costs. Terrestrial applications where components and systems must operate in low temperature environments include cryogenic instrumentation, superconducting magnetic energy storage, magnetic levitation transportation system, and arctic exploration. An on-going research and development program at the NASA Glenn Research Center focuses on the development of reliable electronic devices and efficient power systems capable of surviving in low temperature environments. An overview of the program will be presented in this paper. A description of the low temperature test facilities along with selected data obtained from in-house component testing will also be discussed. Ongoing research activities that are being performed in collaboration with various organizations will also be presented.

Piezoelectric-based hybrid reserve power sources for munitions

NASA Astrophysics Data System (ADS)

Rastegar, J.; Kwok, P.

2017-04-01

Reserve power sources are used extensively in munitions and other devices, such as emergency devices or remote sensors that need to be powered only once and for a relatively short duration. Current chemical reserve power sources, including thermal batteries and liquid reserve batteries sometimes require more than 100 msec to become fully activated. In many applications, however, electrical energy is required in a few msec following the launch event. In such applications, other power sources are needed to provide power until the reserve battery is fully activated. The amount of electrical energy that is required by most munitions before chemical reserve batteries are fully activated is generally small and can be provided by properly designed piezoelectric-based energy harvesting devices. In this paper, the development of a hybrid reserve power source that is constructed by integration of a piezoelectric-based energy harvesting device with a reserve battery to provide power almost instantaneously upon munitions firing or other similar events is being reported. A review of the state of the art in piezoelectric-based electrical energy harvesting methods and devices and their charge collection electronics for use in the developed hybrid power sources is provided together with the results of testing of the piezoelectric component of the power source and its electronic safety and charge collection electronics.

Design integration for minimal energy and cost

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halldane, J.E.

The authors present requirements for creating alternative energy conserving designs including energy management and architectural, plumbing, mechanical, electrical, electronic and optical design. Parameters of power, energy, life cycle costs and benefit for resource for an evaluation by the interested parties are discussed. They present an analysis of power systems through a seasonal power distribution diagram. An analysis of cost systems includes capital cost from the power components, annual costs from the utility energy use, and finance costs with loans, taxes, settlement and design fees. Equations are transposed to the evaluative parameter and are uniquely explicit with consistent symbols, parameter definitions,more » dual and balanced units, unit conversions, criteria for operation, incorporated constants for rapid calculations, references to data in the handbook, other common terms, and instrumentation for the measurement. Each component equation has a key power diagram.« less

Radio-frequency flexible and stretchable electronics: the need, challenges and opportunities

NASA Astrophysics Data System (ADS)

Jung, Yei Hwan; Seo, Jung-Hun; Zhang, Huilong; Lee, Juhwan; Cho, Sang June; Chang, Tzu-Hsuan; Ma, Zhenqiang

2017-05-01

Successful integration of ultrathin flexible or stretchable systems with new applications, such as medical devices and biodegradable electronics, have intrigued many researchers and industries around the globe to seek materials and processes to create high-performance, non-invasive and cost-effective electronics to match those of state-of-the-art devices. Nevertheless, the crucial concept of transmitting data or power wirelessly for such unconventional devices has been difficult to realize due to limitations of radio-frequency (RF) electronics in individual components that form a wireless circuitry, such as antenna, transmission line, active devices, passive devices etc. To overcome such challenges, these components must be developed in a step-by-step manner, as each component faces a number of different challenges in ultrathin formats. Here, we report on materials and design considerations for fabricating flexible and stretchable electronics systems that operate in the microwave level. High-speed flexible active devices, including cost effective Si-based strained MOSFETs, GaAs-based HBTs and GaN-based HEMTs, performing at multi-gigahertz frequencies are presented. Furthermore, flexible or stretchable passive devices, including capacitors, inductors and transmission lines that are vital parts of a microwave circuitry are also demonstrated. We also present unique applications using the presented flexible or stretchable RF components, including wearable RF electronics and biodegradable RF electronics, which were impossible to achieve using conventional rigid, wafer-based technology. Further opportunities like implantable systems exist utilizing such ultrathin RF components, which are discussed in this report as well.

Monolithic control components for high power mm-waves

NASA Astrophysics Data System (ADS)

Armstrong, A.; Goodrich, J.; Moroney, W.; Wheeler, D.

1985-09-01

Monolithic PIN diode arrays are shown to provide significant advances in switching ratios, bandwidth, and high-power capability for millimeter control applications The PIN diodes are arranged in a series/parallel configuration and form an electronically controlled window for switching RF power by applying DC voltage. At Ka band, an SPST switch using the window array (WINAR) design typically has 0.6 dB insertion loss and 22 dB isolation over the 26.5 to 40.0 GHz band. The switch has over 500 W peak power and 25 W average power capability.

Fabrication, characterization, and modeling of a biodegradable battery for transient electronics

NASA Astrophysics Data System (ADS)

Edupuganti, Vineet; Solanki, Raj

2016-12-01

Traditionally, emphasis has been placed on durable, long-lasting electronics. However, electronics that are meant to intentionally degrade over time can actually have significant practical applications. Biodegradable, or transient, electronics would open up opportunities in the field of medical implants, where the need for surgical removal of devices could be eliminated. Environmental sensors and, eventually, consumer electronics would also greatly benefit from this technology. An essential component of transient electronics is the battery, which serves as a biodegradable power source. This work involves the fabrication, characterization, and modeling of a magnesium-based biodegradable battery. Galvanostatic discharge tests show that an anode material of magnesium alloy AZ31 extends battery lifetime by over six times, as compared to pure magnesium. With AZ31, the maximum power and capacity of the fabricated device are 67 μW and 5.2 mAh, respectively, though the anode area is just 0.8 cm2. The development of an equivalent circuit model provided insight into the battery's behavior by extracting fitting parameters from experimental data. The model can accurately simulate device behavior, taking into account its intentional degradation. The size of the device and the power it produces are in accordance with typical levels for low-power transient systems.

Automatic Thermal Infrared Panoramic Imaging Sensor

DTIC Science & Technology

2006-11-01

hibernation, in which power supply to the server computer , the wireless network hardware, the GPS receiver, and the electronic compass / tilt sensor...prototype. At the operator’s command on the client laptop, the receiver wakeup device on the server side will switch on the ATX power supply at the...server, to resume the power supply to all the APTIS components. The embedded computer will resume all of the functions it was performing when put

Nuclear and NBC Contamination Survivability of Medical Materiel

DTIC Science & Technology

1990-03-01

protection devices employed at the equipment signal and power interfaces. 4.2.5.7 (4.x.3) Netronlg.ence - The equipment shall be exposed in such a...hardening approaches shall account for the equipment being passive (i.e., de-energized) as well as being powered (i.e., energized), and shall account for...components used. In addition, electronic systems may exhibit different D-6 vulnerabilities depending on whether the power is on or off, and whether

Development of Power Supply Management Module for Radio Signal Repeaters of Automatic Metering Reading System in Variable Solar Density Conditions

NASA Astrophysics Data System (ADS)

Kondratjevs, K.; Zabasta, A.; Selmanovs-Pless, V.

2016-02-01

In recent years, there has been significant research focus that revolves around harvesting and minimising energy consumption by wireless sensor network nodes. When a sensor node is depleted of energy, it becomes unresponsive and disconnected from the network that can significantly influence the performance of the whole network. The purpose of the present research is to create a power supply management module in order to provide stable operating voltage for autonomous operations of radio signal repeaters, sensors or gateways of WSN. The developed management module is composed of a solar panel, lithium battery and power supply management module. The novelty of the research is the management module, which ensures stable and uninterrupted operations of electronic equipment in various power supply modes in different situations, simultaneously ensuring energy protection and sustainability of the module components. The management module is able to provide power supply of 5 V for electronics scheme independently, without power interruption switching between power sources and power flows in different directions.

Low-noise front-end electronics for detection of intermediate-frequency weak light signals

NASA Astrophysics Data System (ADS)

Lin, Cunbao; Yan, Shuhua; Du, Zhiguang; Wei, Chunhua; Wang, Guochao

2015-02-01

A novel low-noise front-end electronics was proposed for detection of light signals with intensity about 10 μW and frequency above 2.7 MHz. The direct current (DC) power supply, pre-amplifier and main-amplifier were first designed, simulated and then realized. Small-size components were used to make the power supply small, and the pre-amplifier and main-amplifier were the least capacitors to avoid the phase shift of the signals. The performance of the developed front-end electronics was verified in cross-grating diffraction experiments. The results indicated that the output peak-topeak noise of the +/-5 V DC power supply was about 2 mV, and the total output current was 1.25 A. The signal-to-noise ratio (SNR) of the output signal of the pre-amplifier was about 50 dB, and it increased to nearly 60 dB after the mainamplifier, which means this front-end electronics was especially suitable for using in the phase-sensitive and integrated precision measurement systems.

Electronic Components and Circuits for Extreme Temperature Environments

NASA Technical Reports Server (NTRS)

Patterson, Richard L.; Hammoud, Ahmad; Dickman, John E.; Gerber, Scott

2003-01-01

Planetary exploration missions and deep space probes require electrical power management and control systems that are capable of efficient and reliable operation in very low temperature environments. Presently, spacecraft operating in the cold environment of deep space carry a large number of radioisotope heating units in order to maintain the surrounding temperature of the on-board electronics at approximately 20 C. Electronics capable of operation at cryogenic temperatures will not only tolerate the hostile environment of deep space but also reduce system size and weight by eliminating or reducing the radioisotope heating units and their associate structures; thereby reducing system development as well as launch costs. In addition, power electronic circuits designed for operation at low temperatures are expected to result in more efficient systems than those at room temperature. This improvement results from better behavior and tolerance in the electrical and thermal properties of semiconductor and dielectric materials at low temperatures. The Low Temperature Electronics Program at the NASA Glenn Research Center focuses on research and development of electrical components, circuits, and systems suitable for applications in the aerospace environment and deep space exploration missions. Research is being conducted on devices and systems for reliable use down to cryogenic temperatures. Some of the commercial-off-the-shelf as well as developed components that are being characterized include switching devices, resistors, magnetics, and capacitors. Semiconductor devices and integrated circuits including digital-to-analog and analog-to-digital converters, DC/DC converters, operational amplifiers, and oscillators are also being investigated for potential use in low temperature applications. An overview of the NASA Glenn Research Center Low Temperature Electronic Program will be presented in this paper. A description of the low temperature test facilities along with selected data obtained through in-house component and circuit testing will also be discussed. Ongoing research activities that are being performed in collaboration with various organizations will also be presented.

Technical Challenges and Potential Solutions for Cross-Country Multi-Terminal Superconducting DC Power Cables

NASA Astrophysics Data System (ADS)

Al-Taie, A.; Graber, L.; Pamidi, S. V.

2017-12-01

Opportunities for applications of high temperature superconducting (HTS) DC power cables for long distance power transmission in increasing the reliability of the electric power grid and to enable easier integration of distributed renewable sources into the grid are discussed. The gaps in the technology developments both in the superconducting cable designs and cryogenic systems as well as power electronic devices are identified. Various technology components in multi-terminal high voltage DC power transmission networks and the available options are discussed. The potential of ongoing efforts in the development of superconducting DC transmission systems is discussed.

Reliability Assessment of Critical Electronic Components

DTIC Science & Technology

1992-07-01

Failures FLHP - Full Horse Power FSN - Federal Stock Number I Current IC - Integrated Circuit IPB - Illustrated Parts Breakdown K - Boltzmans Constant L...Classified P - Power PC - Printed Circuit PCB - Printed Circuit Board PGA - Pin Grid Array PPM - Parts Per Million PWB - Printed Wiring Board 0...4-59 4.4.3.2.3 Circuit Brcakers ......................................................... 4-59 4.4.3.2.4 Thermal

Measurements of collisionless heating effects in the H-mode of an inductively coupled plasma system

NASA Astrophysics Data System (ADS)

Zaka-Ul-Islam, Mujahid; Graham, Bill; Gans, Timo; Niemi, Kari; O'Connell, Deborah

2013-09-01

Inductively coupled plasma systems (ICPs) for processing applications are often operated at low pressures, in the near-collisionless regime. In this regime, the electron mean free path is comparable or larger than the plasma dimensions. The electron dynamics in such ICPs has been investigated here, using phase and space resolved optical emission spectroscopy (PROES) and Langmuir probe measurements. The PROES measurements are also used to calculate the Fourier harmonics components of the 2D excitation (in the radial axial plane). The experimental system is a standard GEC cell with the axial gap of ~4 cm, powered by 13.56 MHz RF power supply. The gas pressure was varied between 0.5 - 2 Pa. The PROES measurements and Fourier harmonics components confirm many of the previous simulation results in comparable operational regimes. The results show that in the 2D (radial-axial) plane, the plasma power is deposited in a spatially non-uniform and non-linear manner, with axial layers of positive and negative power absorption. The contribution of these nonlinear effects decreases with an increase in the pressure, as observed in previous experimental and simulation results.

One-electron reduced density matrices of strongly correlated harmonium atoms.

PubMed

Cioslowski, Jerzy

2015-03-21

Explicit asymptotic expressions are derived for the reduced one-electron density matrices (the 1-matrices) of strongly correlated two- and three-electron harmonium atoms in the ground and first excited states. These expressions, which are valid at the limit of small confinement strength ω, yield electron densities and kinetic energies in agreement with the published values. In addition, they reveal the ω(5/6) asymptotic scaling of the exchange components of the electron-electron repulsion energies that differs from the ω(2/3) scaling of their Coulomb and correlation counterparts. The natural orbitals of the totally symmetric ground state of the two-electron harmonium atom are found to possess collective occupancies that follow a mixed power/Gaussian dependence on the angular momentum in variance with the simple power-law prediction of Hill's asymptotics. Providing rigorous constraints on energies as functionals of 1-matrices, these results are expected to facilitate development of approximate implementations of the density matrix functional theory and ensure their proper description of strongly correlated systems.

Note: Self-biased voltage to suppress secondary electrons by a ZnO varistor in a compact pulsed neutron generator

NASA Astrophysics Data System (ADS)

Yang, Z.; Li, X.; Li, J.; Long, J. D.; Lan, C. H.; Wang, T.; Dong, P.; He, J. L.

2017-03-01

A large amount of back streaming electrons will bring about a part of current drain on power supply, cause sparking or high-voltage breakdowns, and affect the neutron yield and waveform for a compact sealed-tube pulsed neutron generator. A novel idea which uses a ZnO varistor to provide a constant self-biased voltage to suppress the secondary electrons is introduced. The I-V curve for the ZnO varistor was measured in the experiment. The effects of suppressing the secondary electrons were investigated using a ZnO varistor, linear resistors, and an independent power supply, respectively. The results show that the secondary electrons are suppressed effectively by the compact ZnO varistor, while not increasing the size and the component of the device. It is a promising design for compact sealed-tube neutron generators.

Self-shielded electron linear accelerators designed for radiation technologies

NASA Astrophysics Data System (ADS)

Belugin, V. M.; Rozanov, N. E.; Pirozhenko, V. M.

2009-09-01

This paper describes self-shielded high-intensity electron linear accelerators designed for radiation technologies. The specific property of the accelerators is that they do not apply an external magnetic field; acceleration and focusing of electron beams are performed by radio-frequency fields in the accelerating structures. The main characteristics of the accelerators are high current and beam power, but also reliable operation and a long service life. To obtain these characteristics, a number of problems have been solved, including a particular optimization of the accelerator components and the application of a variety of specific means. The paper describes features of the electron beam dynamics, accelerating structure, and radio-frequency power supply. Several compact self-shielded accelerators for radiation sterilization and x-ray cargo inspection have been created. The introduced methods made it possible to obtain a high intensity of the electron beam and good performance of the accelerators.

Methods for fabrication of flexible hybrid electronics

NASA Astrophysics Data System (ADS)

Street, Robert A.; Mei, Ping; Krusor, Brent; Ready, Steve E.; Zhang, Yong; Schwartz, David E.; Pierre, Adrien; Doris, Sean E.; Russo, Beverly; Kor, Siv; Veres, Janos

2017-08-01

Printed and flexible hybrid electronics is an emerging technology with potential applications in smart labels, wearable electronics, soft robotics, and prosthetics. Printed solution-based materials are compatible with plastic film substrates that are flexible, soft, and stretchable, thus enabling conformal integration with non-planar objects. In addition, manufacturing by printing is scalable to large areas and is amenable to low-cost sheet-fed and roll-to-roll processes. FHE includes display and sensory components to interface with users and environments. On the system level, devices also require electronic circuits for power, memory, signal conditioning, and communications. Those electronic components can be integrated onto a flexible substrate by either assembly or printing. PARC has developed systems and processes for realizing both approaches. This talk presents fabrication methods with an emphasis on techniques recently developed for the assembly of off-the-shelf chips. A few examples of systems fabricated with this approach are also described.

Electric vehicle motors and controllers

NASA Technical Reports Server (NTRS)

Secunde, R. R.

1981-01-01

Improved and advanced components being developed include electronically commutated permanent magnet motors of both drum and disk configuration, an unconventional brush commutated motor, and ac induction motors and various controllers. Test results on developmental motors, controllers, and combinations thereof indicate that efficiencies of 90% and higher for individual components, and 80% to 90% for motor/controller combinations can be obtained at rated power. The simplicity of the developmental motors and the potential for ultimately low cost electronics indicate that one or more of these approaches to electric vehicle propulsion may eventually displace presently used controllers and brush commutated dc motors.

Electric vehicle motors and controllers

NASA Astrophysics Data System (ADS)

Secunde, R. R.

Improved and advanced components being developed include electronically commutated permanent magnet motors of both drum and disk configuration, an unconventional brush commutated motor, and ac induction motors and various controllers. Test results on developmental motors, controllers, and combinations thereof indicate that efficiencies of 90% and higher for individual components, and 80% to 90% for motor/controller combinations can be obtained at rated power. The simplicity of the developmental motors and the potential for ultimately low cost electronics indicate that one or more of these approaches to electric vehicle propulsion may eventually displace presently used controllers and brush commutated dc motors.

Advanced electro-mechanical micro-shutters for thermal infrared night vision imaging and targeting systems

NASA Astrophysics Data System (ADS)

Durfee, David; Johnson, Walter; McLeod, Scott

2007-04-01

Un-cooled microbolometer sensors used in modern infrared night vision systems such as driver vehicle enhancement (DVE) or thermal weapons sights (TWS) require a mechanical shutter. Although much consideration is given to the performance requirements of the sensor, supporting electronic components and imaging optics, the shutter technology required to survive in combat is typically the last consideration in the system design. Electro-mechanical shutters used in military IR applications must be reliable in temperature extremes from a low temperature of -40°C to a high temperature of +70°C. They must be extremely light weight while having the ability to withstand the high vibration and shock forces associated with systems mounted in military combat vehicles, weapon telescopic sights, or downed unmanned aerial vehicles (UAV). Electro-mechanical shutters must have minimal power consumption and contain circuitry integrated into the shutter to manage battery power while simultaneously adapting to changes in electrical component operating parameters caused by extreme temperature variations. The technology required to produce a miniature electro-mechanical shutter capable of fitting into a rifle scope with these capabilities requires innovations in mechanical design, material science, and electronics. This paper describes a new, miniature electro-mechanical shutter technology with integrated power management electronics designed for extreme service infra-red night vision systems.

Thermal Performance Benchmarking: Annual Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moreno, Gilbert

2016-04-08

The goal for this project is to thoroughly characterize the performance of state-of-the-art (SOA) automotive power electronics and electric motor thermal management systems. Information obtained from these studies will be used to: Evaluate advantages and disadvantages of different thermal management strategies; establish baseline metrics for the thermal management systems; identify methods of improvement to advance the SOA; increase the publicly available information related to automotive traction-drive thermal management systems; help guide future electric drive technologies (EDT) research and development (R&D) efforts. The performance results combined with component efficiency and heat generation information obtained by Oak Ridge National Laboratory (ORNL) maymore » then be used to determine the operating temperatures for the EDT components under drive-cycle conditions. In FY15, the 2012 Nissan LEAF power electronics and electric motor thermal management systems were benchmarked. Testing of the 2014 Honda Accord Hybrid power electronics thermal management system started in FY15; however, due to time constraints it was not possible to include results for this system in this report. The focus of this project is to benchmark the thermal aspects of the systems. ORNL's benchmarking of electric and hybrid electric vehicle technology reports provide detailed descriptions of the electrical and packaging aspects of these automotive systems.« less

First NuSTAR Observations of the BL Lac-Type Blazar PKS 2155-304: Constraints on the Jet Content and Distribution of Radiating Particles

NASA Technical Reports Server (NTRS)

Madejski, G. M.; Nalewajko, K.; Madsen, K. K.; Chiang, J.; Balokovic, M.; Paneque, D.; Furniss, A. K.; Hayashida, M.; Urry, C. M.; Sikora, M.;

First NuSTAR Observations of the BL Lac-type Blazar PKS 2155-304: Constraints on the Jet Content and Distribution of Radiating Particles

NASA Astrophysics Data System (ADS)

Madejski, G. M.; Nalewajko, K.; Madsen, K. K.; Chiang, J.; Baloković, M.; Paneque, D.; Furniss, A. K.; Hayashida, M.; Urry, C. M.; Sikora, M.; Ajello, M.; Blandford, R. D.; Harrison, F. A.; Sanchez, D.; Giebels, B.; Stern, D.; Alexander, D. M.; Barret, D.; Boggs, S. E.; Christensen, F. E.; Craig, W. W.; Forster, K.; Giommi, P.; Grefenstette, B.; Hailey, C.; Hornstrup, A.; Kitaguchi, T.; Koglin, J. E.; Mao, P. H.; Miyasaka, H.; Mori, K.; Perri, M.; Pivovaroff, M. J.; Puccetti, S.; Rana, V.; Westergaard, N. J.; Zhang, W. W.; Zoglauer, A.

2016-11-01

We report the first hard X-ray observations with NuSTAR of the BL Lac-type blazar PKS 2155-304, augmented with soft X-ray data from XMM-Newton and γ-ray data from the Fermi Large Area Telescope, obtained in 2013 April when the source was in a very low flux state. A joint NuSTAR and XMM spectrum, covering the energy range 0.5-60 keV, is best described by a model consisting of a log-parabola component with curvature β ={0.3}-0.1+0.2 and a (local) photon index 3.04 ± 0.15 at photon energy of 2 keV, and a hard power-law tail with photon index 2.2 ± 0.4. The hard X-ray tail can be smoothly joined to the quasi-simultaneous γ-ray spectrum by a synchrotron self-Compton component produced by an electron distribution with index p = 2.2. Assuming that the power-law electron distribution extends down to γ min = 1 and that there is one proton per electron, an unrealistically high total jet power of L p ˜ 1047 erg s-1 is inferred. This can be reduced by two orders of magnitude either by considering a significant presence of electron-positron pairs with lepton-to-proton ratio {n}{{e}+{{e}}-}/{n}{{p}}˜ 30, or by introducing an additional, low-energy break in the electron energy distribution at the electron Lorentz factor γ br1 ˜ 100. In either case, the jet composition is expected to be strongly matter-dominated.

Electronics for Deep Space Cryogenic Applications

NASA Technical Reports Server (NTRS)

Patterson, R. L.; Hammond, A.; Dickman, J. E.; Gerber, S. S.; Elbuluk, M. E.; Overton, E.

2002-01-01

Deep space probes and planetary exploration missions require electrical power management and control systems that are capable of efficient and reliable operation in very cold temperature environments. Typically, in deep space probes, heating elements are used to keep the spacecraft electronics near room temperature. The utilization of power electronics designed for and operated at low temperature will contribute to increasing efficiency and improving reliability of space power systems. At NASA Glenn Research Center, commercial-off-the-shelf devices as well as developed components are being investigated for potential use at low temperatures. These devices include semiconductor switching devices, magnetics, and capacitors. Integrated circuits such as digital-to-analog and analog-to-digital converters, DC/DC converters, operational amplifiers, and oscillators are also being evaluated. In this paper, results will be presented for selected analog-to-digital converters, oscillators, DC/DC converters, and pulse width modulation (PWM) controllers.

Pump and Flow Control Subassembly of Thermal Control Subsystem for Photovoltaic Power Module

NASA Technical Reports Server (NTRS)

Motil, Brian; Santen, Mark A.

1993-01-01

The pump and flow control subassembly (PFCS) is an orbital replacement unit (ORU) on the Space Station Freedom photovoltaic power module (PVM). The PFCS pumps liquid ammonia at a constant rate of approximately 1170 kg/hr while providing temperature control by flow regulation between the radiator and the bypass loop. Also, housed within the ORU is an accumulator to compensate for fluid volumetric changes as well as the electronics and firmware for monitoring and control of the photovoltaic thermal control system (PVTCS). Major electronic functions include signal conditioning, data interfacing and motor control. This paper will provide a description of each major component within the PFCS along with performance test data. In addition, this paper will discuss the flow control algorithm and describe how the nickel hydrogen batteries and associated power electronics will be thermally controlled through regulation of coolant flow to the radiator.

FY2009 Oak Ridge National Laboratory Annual Progress Report for the Power Electronics and Electric Machinery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszewski, Mitchell

The U.S. Department of Energy (DOE) and the U.S. Council for Automotive Research (composed of automakers Ford, General Motors, and Chrysler) announced in January 2002 a new cooperative research effort. Known as FreedomCAR (derived from 'Freedom' and 'Cooperative Automotive Research'), it represents DOE's commitment to developing public/private partnerships to fund high-risk, high-payoff research into advanced automotive technologies. Efficient fuel cell technology, which uses hydrogen to power automobiles without air pollution, is a very promising pathway to achieve the ultimate vision. The new partnership replaces and builds upon the Partnership for a New Generation of Vehicles initiative that ran from 1993more » through 2001. The Oak Ridge National Laboratory's (ORNL's) Advanced Power Electronics and Electric Machines (APEEM) subprogram within the Vehicle Technologies Program provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on understanding and improving the way the various new components of tomorrow's automobiles will function as a unified system to improve fuel efficiency. In supporting the development of advanced vehicle propulsion systems, the APEEM effort has enabled the development of technologies that will significantly improve efficiency, costs, and fuel economy. The APEEM subprogram supports the efforts of the FreedomCAR and Fuel Partnership through a three-phase approach intended to: (1) identify overall propulsion and vehicle-related needs by analyzing programmatic goals and reviewing industry's recommendations and requirements and then develop the appropriate technical targets for systems, subsystems, and component research and development activities; (2) develop and validate individual subsystems and components, including electric motors and power electronics; and (3) determine how well the components and subsystems work together in a vehicle environment or as a complete propulsion system and whether the efficiency and performance targets at the vehicle level have been achieved. The research performed under this subprogram will help remove technical and cost barriers to enable the development of technology for use in such advanced vehicles as hybrid electric vehicles (HEVs), plug-in HEVs (PHEVs), all electric vehicles, and fuel-cell-powered automobiles that meet the goals of the Vehicle Technologies Program. A key element in making these advanced vehicles practical is providing an affordable electric traction drive system. This will require attaining weight, volume, and cost targets for the power electronics and electrical machines subsystems of the traction drive system. Areas of development include these: (1) novel traction motor designs that result in increased power density and lower cost; (2) inverter technologies involving new topologies to achieve higher efficiency, with the ability to accommodate higher-temperature environments while achieving high reliability; (3) converter concepts that employ means of reducing the component count and integrating functionality to decrease size, weight, and cost; (4) new onboard battery charging concepts that result in decreased cost and size; (5) more effective thermal control and packaging technologies; and (6) integrated motor/inverter concepts. ORNL's Power Electronics and Electric Machinery Research Center conducts fundamental research, evaluates hardware, and assists in the technical direction of the DOE Vehicle Technologies Program, APEEM subprogram. In this role, ORNL serves on the FreedomCAR Electrical and Electronics Technical Team, evaluates proposals for DOE, and lends its technological expertise to the direction of projects and evaluation of developing technologies. ORNL also executes specific projects for DOE. The following report discusses those projects carried out in FY 2009 and conveys highlights of their accomplishments. Numerous project reviews, technical reports, and papers have been published for these efforts, if the reader is interested in pursuing details of the work.« less

FY 2005 Oak Ridge National Laboratory Annual Progress Report for the Power Electronics and Electric Machinery Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszewski, M

The U.S. Department of Energy (DOE) and the U.S. Council for Automotive Research (composed of automakers Ford, General Motors, and DaimlerChrysler) announced in January 2002 a new cooperative research effort. Known as FreedomCAR (derived from ''Freedom'' and ''Cooperative Automotive Research''), it represents DOE's commitment to developing public/private partnerships to fund high-risk, high-payoff research into advanced automotive technologies. Efficient fuel cell technology, which uses hydrogen to power automobiles without air pollution, is a very promising pathway to achieve the ultimate vision. The new partnership replaces and builds upon the Partnership for a New Generation of Vehicles initiative that ran from 1993more » through 2001. The Vehicle Systems subprogram within the FreedomCAR and Vehicle Technologies Program provides support and guidance for many cutting-edge automotive and heavy truck technologies now under development. Research is focused on understanding and improving the way the various new components of tomorrow's automobiles and heavy trucks will function as a unified system to improve fuel efficiency. This work also supports the development of advanced automotive accessories and the reduction of parasitic losses (e.g., aerodynamic drag, thermal management, friction and wear, and rolling resistance). In supporting the development of hybrid propulsion systems, the Vehicle Systems subprogram has enabled the development of technologies that will significantly improve fuel economy, comply with projected emissions and safety regulations, and use fuels produced domestically. The Vehicle Systems subprogram supports the efforts of the FreedomCAR and Fuel and the 21st Century Truck Partnerships through a three-phase approach intended to: (1) Identify overall propulsion and vehicle-related needs by analyzing programmatic goals and reviewing industry's recommendations and requirements, then develop the appropriate technical targets for systems, subsystems, and component research and development activities; (2) Develop and validate individual subsystems and components, including electric motors, emission control devices, battery systems, power electronics, accessories, and devices to reduce parasitic losses; and (3) Determine how well the components and subsystems work together in a vehicle environment or as a complete propulsion system and whether the efficiency and performance targets at the vehicle level have been achieved. The research performed under the Vehicle Systems subprogram will help remove technical and cost barriers to enable technology for use in such advanced vehicles as hybrid and fuel-cell-powered automobiles that meet the goals of the FreedomCAR Program. A key element in making hybrid electric vehicles practical is providing an affordable electric traction drive system. This will require attaining weight, volume, and cost targets for the power electronics and electrical machines subsystems of the traction drive system. Areas of development include: (1) Novel traction motor designs that result in increased power density and lower cost; (2) Inverter technologies involving new topologies to achieve higher efficiency and the ability to accommodate higher-temperature environments; (3) Converter concepts that employ means of reducing the component count and integrating functionality to decrease size, weight, and cost; (4) More effective thermal control and packaging technologies; and (5) Integrated motor/inverter concepts. The Oak Ridge National Laboratory's (ORNL's) Power Electronics and Electric Machinery Research Center conducts fundamental research, evaluates hardware, and assists in the technical direction of the DOE Office of FreedomCAR and Vehicle Technologies Program, Power Electronics and Electric Machinery Program. In this role, ORNL serves on the FreedomCAR Electrical and Electronics Technical Team, evaluates proposals for DOE, and lends its technological expertise to the direction of projects and evaluation of developing technologies. ORNL also executes specific projects for DOE. The following report discusses those projects carried out in FY 2004 and conveys highlights of their accomplishments. Numerous project reviews, technical reports, and papers have been published for these efforts, if the reader is interested in pursuing details of the work.« less

Oak Ridge National Laboratory Annual Progress Report for the Power Electronics and Electric Machinery Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszewski, M.

The U.S. Department of Energy (DOE) and the U.S. Council for Automotive Research (composed of automakers Ford, General Motors, and DaimlerChrysler) announced in January 2002 a new cooperative research effort. Known as FreedomCAR (derived from 'Freedom' and 'Cooperative Automotive Research'), it represents DOE's commitment to developing public/private partnerships to fund high-risk, high-payoff research into advanced automotive technologies. Efficient fuel cell technology, which uses hydrogen to power automobiles without air pollution, is a very promising pathway to achieve the ultimate vision. The new partnership replaces and builds upon the Partnership for a New Generation of Vehicles initiative that ran from 1993more » through 2001. The Vehicle Systems subprogram within the FreedomCAR and Vehicle Technologies Program provides support and guidance for many cutting-edge automotive and heavy truck technologies now under development. Research is focused on understanding and improving the way the various new components of tomorrow's automobiles and heavy trucks will function as a unified system to improve fuel efficiency. This work also supports the development of advanced automotive accessories and the reduction of parasitic losses (e.g., aerodynamic drag, thermal management, friction and wear, and rolling resistance). In supporting the development of hybrid propulsion systems, the Vehicle Systems subprogram has enabled the development of technologies that will significantly improve fuel economy, comply with projected emissions and safety regulations, and use fuels produced domestically. The Vehicle Systems subprogram supports the efforts of the FreedomCAR and Fuel Partnership and the 21st Century Truck Partnership through a three-phase approach intended to: (1) Identify overall propulsion and vehicle-related needs by analyzing programmatic goals and reviewing industry's recommendations and requirements and then develop the appropriate technical targets for systems, subsystems, and component research and development activities; (2) Develop and validate individual subsystems and components, including electric motors, emission control devices, battery systems, power electronics, accessories, and devices to reduce parasitic losses; and (3) Determine how well the components and subsystems work together in a vehicle environment or as a complete propulsion system and whether the efficiency and performance targets at the vehicle level have been achieved. The research performed under the Vehicle Systems subprogram will help remove technical and cost barriers to enable the development of technology for use in such advanced vehicles as hybrid and fuel-cell-powered automobiles that meet the goals of the FreedomCAR Program. A key element in making hybrid electric vehicles practical is providing an affordable electric traction drive system. This will require attaining weight, volume, and cost targets for the power electronics and electrical machines subsystems of the traction drive system. Areas of development include these: (1) Novel traction motor designs that result in increased power density and lower cost; (2) Inverter technologies involving new topologies to achieve higher efficiency and the ability to accommodate higher-temperature environments; (3) Converter concepts that employ means of reducing the component count and integrating functionality to decrease size, weight, and cost; (4) More effective thermal control and packaging technologies; and (5) Integrated motor/inverter concepts. The Oak Ridge National Laboratory's (ORNL's) Power Electronics and Electric Machinery Research Center conducts fundamental research, evaluates hardware, and assists in the technical direction of the DOE Office of FreedomCAR and Vehicle Technologies Program, Power Electronics and Electric Machinery Program. In this role, ORNL serves on the FreedomCAR Electrical and Electronics Technical Team, evaluates proposals for DOE, and lends its technological expertise to the direction of projects and evaluation of developing technologies. ORNL also executes specific projects for DOE. The following report discusses those projects carried out in FY 2006 and conveys highlights of their accomplishments. Numerous project reviews, technical reports, and papers have been published for these efforts, if the reader is interested in pursuing details of the work. Summaries of major accomplishments for each technical project are give.« less

An Innovative Very Low Thermal Power Waste Heat Recovery System for Thermal Control of Deep Space Missions: A Thermal Flask in Space

NASA Technical Reports Server (NTRS)

Bhandari, Pradeep

2015-01-01

Future missions to deep space, such as those to the outer planets (Jupiter, Saturn, etc.), which would rely on solar photovoltaic power, would need extremely large solar arrays to produce sufficient power for their operations because solar intensity is so low at those locations. Hence any additional power that would be needed for thermal control is extremely limited. Previous deep space missions like Juno (to Jupiter) required almost 200 W of electrical power for thermal control. This is prohibitively large for many future mission concepts, and leads to them needing very large solar arrays. For Saturn, where the solar flux is 1/4th the flux at Jupiter, this would entail an extremely large increase in the solar array size to accommodate the need for thermal survival power, which would be prohibitively large in size and mass, and very expensive. Hence there is a need to come up with a thermal architecture and design options that would not need such prohibitively large thermal power levels. One solution relies on harvesting the pre-existing waste heat from all the heat dissipation that would be present from operation of electronics, instruments, etc. for their own functionality. For example, for a generic Saturn mission, the various electronics would already dissipate about 200 Watts of heat that is simply "thrown away" to space from the spacecraft surfaces. The amount of thermal power that would be required for the safe thermal control of components within the spacecraft in deep space would be roughly of this magnitude for this class of spacecraft. So it makes good sense to try to harvest the waste heat and employ it to maintain the temperatures of all the components within their allowable limits. In particular, propulsion systems typically need to be kept above their freezing limits, around room temperature (15 C). Electronics needs to be kept typically above -40 C and batteries above -20 C. The next question becomes how to harvest this waste heat and direct it to the components that would need it for their survival. The proposed system utilizes a mechanically pumped, single phase fluid loop to pick up the waste heat from components attached to this loop's tubing and then directed to a thermal flask that has tubing attached to it. The thermal flask is cylindrically shaped and contains essentially all systems and components in the spacecraft within it, with the exception of the solar array, antennae, thrusters and various apertures of instruments, etc. to allow them an unobstructed view of space. Waste heat from the heat-dissipating components warms up the fluid and is carried to the flask surface and deposited on it via the fluid loop's flow. The entire flask is covered with Multi-Layered Insulation (MLI) to minimize the heat loss from the flask and allow it to remain warm. Hence the flask essentially creates a thermal environment within which the spacecraft components reside. The temperature of the components within the flask is then essentially the same as the temperature of the flask. This approach could be a very enabling feature for deep space missions. This paper describes the approach utilized for this thermal architecture, along with its mechanical and implementation aspects. Additionally it will compare and contrast this approach with the more conventional solutions utilized earlier.

Embedded Thermal Control for Spacecraft Subsystems Miniaturization

NASA Technical Reports Server (NTRS)

Didion, Jeffrey R.

2014-01-01

Optimization of spacecraft size, weight and power (SWaP) resources is an explicit technical priority at Goddard Space Flight Center. Embedded Thermal Control Subsystems are a promising technology with many cross cutting NSAA, DoD and commercial applications: 1.) CubeSatSmallSat spacecraft architecture, 2.) high performance computing, 3.) On-board spacecraft electronics, 4.) Power electronics and RF arrays. The Embedded Thermal Control Subsystem technology development efforts focus on component, board and enclosure level devices that will ultimately include intelligent capabilities. The presentation will discuss electric, capillary and hybrid based hardware research and development efforts at Goddard Space Flight Center. The Embedded Thermal Control Subsystem development program consists of interrelated sub-initiatives, e.g., chip component level thermal control devices, self-sensing thermal management, advanced manufactured structures. This presentation includes technical status and progress on each of these investigations. Future sub-initiatives, technical milestones and program goals will be presented.

k-filtering applied to Cluster density measurements in the Solar Wind: Early findings

NASA Astrophysics Data System (ADS)

Jeska, Lauren; Roberts, Owen; Li, Xing

2014-05-01

Studies of solar wind turbulence indicate that a large proportion of the energy is Alfvénic (incompressible) at inertial scales. The properties of the turbulence found in the dissipation range are still under debate ~ while it is widely believed that kinetic Alfvén waves form the dominant component, the constituents of the remaining compressible turbulence are disputed. Using k-filtering, the power can be measured without assuming the validity of Taylor's hypothesis, and its distribution in (ω, k)-space can be determined to assist the identification of weak turbulence components. This technique is applied to Cluster electron density measurements and compared to the power in |B(t)|. As the direct electron density measurements from the WHISPER instrument have a low cadency of only 2.2s, proxy data derived from the spacecraft potential, measured every 0.2s by the EFW instrument, are used to extend this study to ion scales.

The Shock and Vibration Bulletin. Part 4. Prediction and Experimental Techniques, Isolation and Damping

DTIC Science & Technology

1973-06-01

one in laboratory tests. All components of the hydraulic power supply system, with the exceptions of the pumps and the heat exchanger, are located...servoactuator operated by a hydraulic power supply and a control electronics package mounted inside the cabin. For the seat isolation system, the...compensate for the static load b>ing supported. The actuators are the sole supportl.g link in the vertical direction. Hydraulic Power Supply The

Beam conditioner for free electron lasers and synchrotrons

DOEpatents

Liu, H.; Neil, G.R.

1998-09-08

A focused optical has been used to introduce an optical pulse, or electromagnetic wave, collinear with the electron beam in a free electron laser or synchrotron thereby adding an axial field component that accelerates the electrons on the radial outside of the distribution of electrons in the electron beam. This invention consists of using the axial electrical component of a TEM{sub 10} mode Gaussian beam in vacuum to condition the electron beam and speed up the outer electrons in the beam. The conditioning beam should possess about the same diameter as the electron beam. The beam waist of the conditioning wave must be located around the entrance of the undulator longitudinally to have a net energy exchange between the electrons in the outer part of the distribution and the conditioning wave owing to the natural divergence of a Gaussian beam. By accelerating the outer electrons, the outer and core electrons are caused to stay in phase. This increases the fraction of the electron beam energy that is converted to light thereby improving the efficiency of conversion of energy to light and therefore boosting the power output of the free electron laser and synchrotron. 4 figs.

Beam conditioner for free electron lasers and synchrotrons

DOEpatents

Liu, Hongxiu; Neil, George R.

1998-01-01

A focused optical is been used to introduce an optical pulse, or electromagnetic wave, colinearly with the electron beam in a free electron laser or synchrotron thereby adding an axial field component that accelerates the electrons on the radial outside of the distribution of electrons in the electron beam. This invention consists of using the axial electrical component of a TEM.sub.10 mode Gaussian beam in vacuum to condition the electron beam and speed up the outer electrons in the beam. The conditioning beam should possess about the same diameter as the electron beam. The beam waist of the conditioning wave must be located around the entrance of the undulator longitudinally to have a net energy exchange between the electrons in the outer part of the distribution and the conditioning wave owing to the natural divergence of a Gaussian beam. By accelerating the outer electrons, the outer and core electrons are caused to stay in phase. This increases the fraction of the electron beam energy that is converted to light thereby improving the efficiency of conversion of energy to light and therefore boosting the power output of the free electron laser and synchrotron.

Architectured Materials to Improve the Reliability of Power Electronics Modules: Substrate and Lead-Free Solder

NASA Astrophysics Data System (ADS)

Kaabi, Abderrahmen; Bienvenu, Yves; Ryckelynck, David; Pierre, Bertrand

2014-03-01

Power electronics modules (>100 A, >500 V) are essential components for the development of electrical and hybrid vehicles. These modules are formed from silicon chips (transistors and diodes) assembled on copper substrates by soldering. Owing to the fact that the assembly is heterogeneous, and because of thermal gradients, shear stresses are generated in the solders and cause premature damage to such electronics modules. This work focuses on architectured materials for the substrate and on lead-free solders to reduce the mechanical effects of differential expansion, improve the reliability of the assembly, and achieve a suitable operating temperature (<175°C). These materials are composites whose thermomechanical properties have been optimized by numerical simulation and validated experimentally. The substrates have good thermal conductivity (>280 W m-1 K-1) and a macroscopic coefficient of thermal expansion intermediate between those of Cu and Si, as well as limited structural evolution in service conditions. An approach combining design, optimization, and manufacturing of new materials has been followed in this study, leading to improved thermal cycling behavior of the component.

Semiconductor optoelectronic devices for free-space optical communications

NASA Technical Reports Server (NTRS)

Katz, J.

1983-01-01

The properties of individual injection lasers are reviewed, and devices of greater complexity are described. These either include or are relevant to monolithic integration configurations of the lasers with their electronic driving circuitry, power combining methods of semiconductor lasers, and electronic methods of steering the radiation patterns of semiconductor lasers and laser arrays. The potential of AlGaAs laser technology for free-space optical communications systems is demonstrated. These solid-state components, which can generate and modulate light, combine the power of a number of sources and perform at least part of the beam pointing functions. Methods are proposed for overcoming the main drawback of semiconductor lasers, that is, their inability to emit the needed amount of optical power in a single-mode operation.

Impact of Radiation Hardness and Operating Temperatures of Silicon Carbide Electronics on Space Power System Mass

NASA Technical Reports Server (NTRS)

Juhasz, Albert J.; Tew, Roy C.; Schwarze, Gene E.

1998-01-01

The effect of silicon carbide (SiC) electronics operating temperatures on Power Management and Distribution (PMAD), or Power Conditioning (PC), subsystem radiator size and mass requirements was evaluated for three power output levels (100 kW(e) , 1 MW(e), and 10 MW(e)) for near term technology ( i.e. 1500 K turbine inlet temperature) Closed Cycle Gas Turbine (CCGT) power systems with a High Temperature Gas Reactor (HTGR) heat source. The study was conducted for assumed PC radiator temperatures ranging from 370 to 845 K and for three scenarios of electrical energy to heat conversion levels which needed to be rejected to space by means of the PC radiator. In addition, during part of the study the radiation hardness of the PC electronics was varied at a fixed separation distance to estimate its effect on the mass of the instrument rated reactor shadow shield. With both the PC radiator and the conical shadow shield representing major components of the overall power system the influence of the above on total power system mass was also determined. As expected, results show that the greatest actual mass savings achieved by the use of SiC electronics occur with high capacity power systems. Moreover, raising the PC radiator temperature above 600 K yields only small additional system mass savings. The effect of increased radiation hardness on total system mass is to reduce system mass by virtue of lowering the shield mass.

Solar-powered unmanned aerial vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reinhardt, K.C.; Lamp, T.R.; Geis, J.W.

1996-12-31

An analysis was performed to determine the impact of various power system components and mission requirements on the size of solar-powered high altitude long endurance (HALE)-type aircraft. The HALE unmanned aerial vehicle (UAV) has good potential for use in many military and civil applications. The primary power system components considered in this study were photovoltaic (PV) modules for power generation and regenerative fuel cells for energy storage. The impact of relevant component performance on UAV size and capability were considered; including PV module efficiency and mass, power electronics efficiency, and fuel cell specific energy. Mission parameters such as time ofmore » year, flight altitude, flight latitude, and payload mass and power were also varied to determine impact on UAV size. The aircraft analysis method used determines the required aircraft wing aspect ratio, wing area, and total mass based on maximum endurance or minimum required power calculations. The results indicate that the capacity of the energy storage system employed, fuel cells in this analysis, greatly impacts aircraft size, whereas the impact of PV module efficiency and mass is much less important. It was concluded that an energy storage specific energy (total system) of 250--500 Whr/kg is required to enable most useful missions, and that PV cells with efficiencies greater than {approximately} 12% are suitable for use.« less

Radiological considerations in the operation of the low-energy undulator test line (LEUTL).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moe, H.J.

1998-11-11

The Low-Energy Undulator Test Line (LEUTL) is a facility that uses the existing APS linac to accelerate electrons up to an energy of 700 MeV. These electrons are transported through the Pm into a portion of the booster synchrotrons and on into the LEUTL main enclosure (MIL 97). Figure 1 shows the layout of the LEUTL building, which consists of an earth-benned concrete enclosure and an end-station building. The concrete enclosure houses the electron beamline, test undulator, and beam dump. This facility is about 51 m long and 3.66 m wide. Technical components and diagnostics for characterizing the undulator lightmore » are found in the end station. This building has about 111 m{sup 2} of floor space. This note deals with the radiological considerations of operations using electrons up to 700 MeV and at power levels up to the safety envelope of 1 kW. Previous radiological considerations for electron and positron operations in the linac, PAR, and synchrotrons have been addressed else-where (MOE 93a, 93b, and 93c). Much of the methodology discussed in the previous writeups, as well as in MOE 94, has been used in the computations in this note. The radiological aspects that are addressed include the following: prompt secondary radiation (bremsstrahlung, giant resonance neutrons, medium- and high-energy neutrons) produced by electrons interacting in a beam stop or in component structures; skyshine radiation, which produces a radiation field in nearby areas and at the nearest off-site location; radioactive gases produced by neutron irradiation of air in the vicinity of a particle loss site; noxious gases (ozone and others) produced in air by the escaping bremsstrahlung radiation that results from absorbing particles in the components; activation of the LEUTL components that results in a residual radiation field in the vicinity of these materials following shutdown; potential activation of water used for cooling the magnets and other purposes in the tunnel; and evaluation of the radiation fields due to escaping gas bremsstrahlung. Estimated dose rates have been computed or scaled (in the case of 400 MeV electrons) outside of the bermed tunnel, in Building 412, and in the Klystron Gallery for several modes of operation, including potential safety envelope beam power, normal beam power and MCI (maximum credible incident) conditions. Radiological aspects of shielding changes to the synchrotrons and their effect upon operations are addressed in MOE 97. No change in the safety envelope for synchrotrons operation was warranted.« less

Independent control of electron energy and density using a rotating magnetic field in inductively coupled plasmas

NASA Astrophysics Data System (ADS)

Kondo, Takahiro; Ohta, Masayuki; Ito, Tsuyohito; Okada, Shigefumi

2013-09-01

Effects of a rotating magnetic field (RMF) on the electron energy distribution function (EEDF) and on the electron density are investigated with the aim of controlling the radical composition of inductively coupled plasmas. By adjusting the RMF frequency and generation power, the desired electron density and electron energy shift are obtained. Consequently, the amount and fraction of high-energy electrons, which are mostly responsible for direct dissociation processes of raw molecules, will be controlled externally. This controllability, with no electrode exposed to plasma, will enable us to control radical components and their flux during plasma processing.

Electronically steerable millimeter wave antenna techniques for space shuttle applications

NASA Technical Reports Server (NTRS)

Kummer, W. H.

1975-01-01

A large multi-function antenna aperture and related components are described which will perform electronic steering of one or more beams for two of the three applications envisioned: (1) communications, (2) radar, and (3) radiometry. The array consists of a 6-meter folded antenna that fits into two pallets. The communications frequencies are 20 and 30 GHz, while the radar is to operate at 13.9 GHz. Weight, prime power, and volumes are given parametrically; antenna designs, electronics configurations, and mechanical design were studied.

Ultrawide-Bandgap Semiconductors: Research Opportunities and Challenges

DTIC Science & Technology

2017-02-03

particularly for power electronics applications in hybrid and electric vehicles, power supplies, and photovoltaic ( PV ) inverters. Ultrawide-Bandgap...the one hand, Ga2O3-based optoelectronic devices such as solar -blind DUV photodetectors are expected to be useful for a variety of applications (e.g...system, and which are core components in aircraft, spacecraft, solar photovoltaic installations, electric vehicles, and military systems such as all

Spatial dimensions of the electron diffusion region in anti-parallel magnetic reconnection

NASA Astrophysics Data System (ADS)

Nakamura, Takuma; Nakamura, Rumi; Haseagwa, Hiroshi

2016-03-01

Spatial dimensions of the detailed structures of the electron diffusion region in anti-parallel magnetic reconnection were analyzed based on two-dimensional fully kinetic particle-in-cell simulations. The electron diffusion region in this study is defined as the region where the positive reconnection electric field is sustained by the electron inertial and non-gyrotropic pressure components. Past kinetic studies demonstrated that the dimensions of the whole electron diffusion region and the inner non-gyrotropic region are scaled by the electron inertial length de and the width of the electron meandering motion, respectively. In this study, we successfully obtained more precise scalings of the dimensions of these two regions than the previous studies by performing simulations with sufficiently small grid spacing (1/16-1/8 de) and a sufficient number of particles (800 particles cell-1 on average) under different conditions changing the ion-to-electron mass ratio, the background density and the electron βe (temperature). The obtained scalings are adequately supported by some theories considering spatial variations of field and plasma parameters within the diffusion region. In the reconnection inflow direction, the dimensions of both regions are proportional to de based on the background density. Both dimensions also depend on βe based on the background values, but the dependence in the inner region ( ˜ 0.375th power) is larger than the whole region (0.125th power) reflecting the orbits of meandering and accelerated electrons within the inner region. In the outflow direction, almost only the non-gyrotropic component sustains the positive reconnection electric field. The dimension of this single-scale diffusion region is proportional to the ion-electron hybrid inertial length (dide)1/2 based on the background density and weakly depends on the background βe with the 0.25th power. These firm scalings allow us to predict observable dimensions in real space which are indeed in reasonable agreement with past in situ spacecraft observations in the Earth's magnetotail and have important implications for future observations with higher resolutions such as the NASA Magnetospheric Multiscale (MMS) mission.

10 GHz dual loop opto-electronic oscillator without RF-amplifiers

NASA Astrophysics Data System (ADS)

Zhou, Weimin; Okusaga, Olukayode; Nelson, Craig; Howe, David; Carter, Gary

2008-02-01

We report the first demonstration of a 10 GHz dual-fiber-loop Opto-Electronic Oscillator (OEO) without RF-amplifiers. Using a recently developed highly efficient RF-Photonic link with RF-to-RF gain facilitated by a high power laser, highly efficient optical modulator and high power phototectectors, we have built an amplifier-less OEO that eliminates the phase noise produced by the electronic amplifier. The dual-loop approach can provide additional gain and reduce unwanted multi-mode spurs. However, we have observed RF phase noise produced by the high power laser include relative intensity noise (RIN) and noise related to the laser's electronic control system. In addition, stimulated Brillouin scattering limits the fiber loop's length to ~2km at the 40mW laser power needed to provide the RF gain which limits the system's quality factor, Q. We have investigated several different methods for solving these problems. One promising technique is the use of a multi-longitudinal-mode laser to carry the RF signal, maintaining the total optical power but reducing the optical power of each mode to eliminate the Brillouin scattering in a longer fiber thereby reducing the phase noise of the RF signal produced by the OEO. This work shows that improvement in photonic components increases the potential for more RF system applications such as an OEO's with higher performance and new capabilities.

Comfortable, lightweight safety helmet holds radio transmitter, receiver

NASA Technical Reports Server (NTRS)

Atlas, N. D.

1964-01-01

For two-way radio communication where safety gear is required, a lightweight helmet with few protrusions has been designed. The electronics components and power supply are mounted between the inner and outer shells, and resilient padding is used for the lining.

Modeling of a Von Platen-Munters diffusion absorption refrigeration cycle

NASA Astrophysics Data System (ADS)

Agostini, Bruno; Agostini, Francesco; Habert, Mathieu

2016-09-01

This article presents a thermodynamical model of a Von-Platen diffusion absorption refrigeration cycle for power electronics applications. It is first validated by comparison with data available in the literature for the classical water-ammonia-helium cycle for commercial absorption fridges. Then new operating conditions corresponding to specific ABB applications, namely high ambient temperature and new organic fluids combinations compatible with aluminium are simulated and discussed. The target application is to cool power electronics converters in harsh environments with high ambient temperature by providing refrigeration without compressor, for passive components losses of about 500 W, with a compact and low cost solution.

New Results from Fermi-LAT and Their Implications for the Nature of Dark Matter and the Origin of Cosmic Rays

NASA Technical Reports Server (NTRS)

Moiseev, Alexander

2009-01-01

The measured spectrum is compatible with a power law within our current systematic errors. The spectral index (-3.04) is harder than expected from previous experiments and simple theoretical considerations. "Pre-Fermi" diffusive model requires a harder electron injection spectrum (by 0.12) to fit the Fermi data, but inconsistent with positron excess reported by Pamela if it extends to higher energy. Additional component of electron flux from local source(s) may solve the problem; its origin, astrophysical or exotic, is still unclear. Valuable contribution to the calculation of IC component of diffuse gamma radiation.

Characterization and Reliability of Vertical N-Type Gallium Nitride Schottky Contacts

DTIC Science & Technology

2016-09-01

barrier diode SEM scanning electron microscopy SiC silicon carbide SMU source measure unit xvi THIS PAGE INTENTIONALLY LEFT BLANK xvii...arguably the Schottky barrier diode (SBD). The SBD is a fundamental component in the majority of power electronic devices; specifically, those used in...Ishizuka, and Ueno demonstrated the long-term reliability of vertical metal-GaN Schottky barrier diodes through their analysis of the degradation

Conceptual study of a 250 kW planar SOFC system for CHP application

NASA Astrophysics Data System (ADS)

Fontell, E.; Kivisaari, T.; Christiansen, N.; Hansen, J.-B.; Pålsson, J.

In August 2002, Wärtsilä Corporation and Haldor Topsøe A/S entered into a co-operation agreement to start joint development program within the planar SOFC technology. The development program aims to bring to the market highly efficient, clean and cost competitive fuel cell systems with power outputs above 200 kW for distributed power generation with CHP and for marine applications. In this study, the product concept for a 250 kW natural gas-fuelled atmospheric SOFC plant has been studied. The process has been calculated and optimised for high electrical efficiency. In the calculations, system efficiencies more than 55-85% (electrical co-generation) have been reached. The necessary balance of plant (BoP) components have been identified and the concept for grid connection has been defined. The BoP includes fuel and air supply, anode re-circulation, start-up steam, purge gas, exhaust gas heat recovery, back-up power, power electronics and control system. Based on the analysed system and component information, a conceptual design and cost break down structure for the product have been made. The cost breakdown shows that the stack, system control and power electronics are the major cost factors, while the remaining BoP equipment stands for a minor share of the manufacturing cost. Finally, the feasibility of the SOFC plants has been compared to gas engines.

A Multi-Purpose Modular Electronics Integration Node for Exploration Extravehicular Activity

NASA Technical Reports Server (NTRS)

Hodgson, Edward; Papale, William; Wichowski, Robert; Rosenbush, David; Hawes, Kevin; Stankiewicz, Tom

2013-01-01

As NASA works to develop an effective integrated portable life support system design for exploration Extravehicular activity (EVA), alternatives to the current system s electrical power and control architecture are needed to support new requirements for flexibility, maintainability, reliability, and reduced mass and volume. Experience with the current Extravehicular Mobility Unit (EMU) has demonstrated that the current architecture, based in a central power supply, monitoring and control unit, with dedicated analog wiring harness connections to active components in the system has a significant impact on system packaging and seriously constrains design flexibility in adapting to component obsolescence and changing system needs over time. An alternative architecture based in the use of a digital data bus offers possible wiring harness and system power savings, but risks significant penalties in component complexity and cost. A hybrid architecture that relies on a set of electronic and power interface nodes serving functional models within the Portable Life Support System (PLSS) is proposed to minimize both packaging and component level penalties. A common interface node hardware design can further reduce penalties by reducing the nonrecurring development costs, making miniaturization more practical, maximizing opportunities for maturation and reliability growth, providing enhanced fault tolerance, and providing stable design interfaces for system components and a central control. Adaptation to varying specific module requirements can be achieved with modest changes in firmware code within the module. A preliminary design effort has developed a common set of hardware interface requirements and functional capabilities for such a node based on anticipated modules comprising an exploration PLSS, and a prototype node has been designed assembled, programmed, and tested. One instance of such a node has been adapted to support testing the swingbed carbon dioxide and humidity control element in NASA s advanced PLSS 2.0 test article. This paper will describe the common interface node design concept, results of the prototype development and test effort, and plans for use in NASA PLSS 2.0 integrated tests.

Human motion energy harvesting using a piezoelectric MFC patch.

PubMed

Bassani, Giulia; Filippeschi, Alessandro; Ruffaldi, Emanuele

2015-01-01

The improvements in efficiency of electronic components and miniaturization is quickly pushing wearable devices. Kinetic human energy harvesting is a way to power these components reducing the need of batteries replacement since walking or running is how humans already expend much of their daily energy. This work explores the case of kinetic energy from bending of a piezoelectric patch. For assessing the quality of the system, a testing setup has been designed and controlled by means of knee joint recordings obtained from a large motion dataset. The promising result of the chosen patch is an output power of 2.6μW associated to a run activity.

Observation of microwave absorption and emission from incoherent electron tunneling through a normal-metal-insulator-superconductor junction.

PubMed

Masuda, Shumpei; Tan, Kuan Y; Partanen, Matti; Lake, Russell E; Govenius, Joonas; Silveri, Matti; Grabert, Hermann; Möttönen, Mikko

2018-03-02

We experimentally study nanoscale normal-metal-insulator-superconductor junctions coupled to a superconducting microwave resonator. We observe that bias-voltage-controllable single-electron tunneling through the junctions gives rise to a direct conversion between the electrostatic energy and that of microwave photons. The measured power spectral density of the microwave radiation emitted by the resonator exceeds at high bias voltages that of an equivalent single-mode radiation source at 2.5 K although the phonon and electron reservoirs are at subkelvin temperatures. Measurements of the generated power quantitatively agree with a theoretical model in a wide range of bias voltages. Thus, we have developed a microwave source which is compatible with low-temperature electronics and offers convenient in-situ electrical control of the incoherent photon emission rate with a predetermined frequency, without relying on intrinsic voltage fluctuations of heated normal-metal components or suffering from unwanted losses in room temperature cables. Importantly, our observation of negative generated power at relatively low bias voltages provides a novel type of verification of the working principles of the recently discovered quantum-circuit refrigerator.

Cascade model of gamma-ray bursts: Power-law and annihilation-line components

NASA Technical Reports Server (NTRS)

Harding, A. K.; Sturrock, P. A.; Daugherty, J. K.

1988-01-01

If, in a neutron star magnetosphere, an electron is accelerated to an energy of 10 to the 11th or 12th power eV by an electric field parallel to the magnetic field, motion of the electron along the curved field line leads to a cascade of gamma rays and electron-positron pairs. This process is believed to occur in radio pulsars and gamma ray burst sources. Results are presented from numerical simulations of the radiation and photon annihilation pair production processes, using a computer code previously developed for the study of radio pulsars. A range of values of initial energy of a primary electron was considered along with initial injection position, and magnetic dipole moment of the neutron star. The resulting spectra was found to exhibit complex forms that are typically power law over a substantial range of photon energy, and typically include a dip in the spectrum near the electron gyro-frequency at the injection point. The results of a number of models are compared with data for the 5 Mar., 1979 gamma ray burst. A good fit was found to the gamma ray part of the spectrum, including the equivalent width of the annihilation line.

Low-Temperature Spacecraft: Challenges/Opportunities

NASA Technical Reports Server (NTRS)

Dickman, J. E.; Patterson, R. L.; Overton, E.; Hammoud, A. N.; Gerber, S. S.

2001-01-01

Imagine sending a spacecraft into deep space that operates at the ambient temperature of its environment rather than hundreds of degrees Kelvin warmer. The average temperature of a spacecraft warmed only by the sun drops from 279 K near the Earth's orbit to 90 K near the orbit of Saturn, and to 44 K near Pluto's orbit. At present, deep space probes struggle to maintain an operating temperature near 300 K for the onboard electronics. To warm the electronics without consuming vast amounts of electrical energy, radioisotope heater units (RHUs) are used in vast numbers. Unfortunately, since RHU are always 'on', an active thermal management system is required to reject the excess heat. A spacecraft designed to operate at cryogenic temperatures and shielded from the sun by a large communication dish or solar cell array could be less complex, lighter, and cheaper than current deep space probes. Before a complete low-temperature spacecraft becomes a reality, there are several challenges to be met. Reliable cryogenic power electronics is one of the major challenges. The Low-Temperature Power Electronics Research Group at NASA Glenn Research Center (GRC) has demonstrated the ability of some commercial off the shelf power electronic components to operate at temperatures approaching that of liquid nitrogen (77 K). Below 77 K, there exists an opportunity for the development of reliable semiconductor power switching technologies other than bulk silicon CMOS. This paper will report on the results of NASA GRC's Low-Temperature Power Electronics Program and discuss the challenges to (opportunities for) the creation of a low-temperature spacecraft.

Low-energy Electrons in Gamma-Ray Burst Afterglow Models

NASA Astrophysics Data System (ADS)

Jóhannesson, Guđlaugur; Björnsson, Gunnlaugur

2018-05-01

Observations of gamma-ray burst (GRB) afterglows have long provided the most detailed information about the origin of this spectacular phenomenon. The model that is most commonly used to extract physical properties of the event from the observations is the relativistic fireball model, where ejected material moving at relativistic speeds creates a shock wave when it interacts with the surrounding medium. Electrons are accelerated in the shock wave, generating the observed synchrotron emission through interactions with the magnetic field in the downstream medium. It is usually assumed that the accelerated electrons follow a simple power-law distribution in energy between specific energy boundaries, and that no electron exists outside these boundaries. This Letter explores the consequences of adding a low-energy power-law segment to the electron distribution with energy that contributes insignificantly to the total energy budget of the distribution. The low-energy electrons have a significant impact on the radio emission, providing synchrotron absorption and emission at these long wavelengths. Shorter wavelengths are affected through the normalization of the distribution. The new model is used to analyze the light curves of GRB 990510, and the resulting parameters are compared to a model without the extra electrons. The quality of the fit and the best-fit parameters are significantly affected by the additional model component. The new component is in one case found to strongly affect the X-ray light curves, showing how changes to the model at radio frequencies can affect light curves at other frequencies through changes in best-fit model parameters.

Applications and research on nano power electronics: an adventure beyond quantum electronics

NASA Astrophysics Data System (ADS)

Chakraborty, Arindam; Emadi, Ali

2005-06-01

This paper is a roadmap to the exhaustive role of the newly emerging field of nanotechnology in various application and research areas. Some of the today's important topics are plasma, dielectric layer semiconductor, and carbon nanoparticle based technologies. Carbon nanotubes are very useful for the purpose of fabricating nano opto power devices. The basic concept behind tunneling of electrons has been utilized to define another scope of this technology, and thus came many quantum scale tunneling devices and elements. Fabrication of crystal semiconductors of high quality along with oxides of nano aspect would give rise to superior device performance and find applications such as LEDs, LASER, VLSI technology and also in highly efficient solar cells. Many nano-research based organizations are fully devoted to develop nano power cells, which would give birth to new battery cells, tunneling devises, with high power quality, longer lives, and higher activation rates. Different electronics industries as well as the military organizations would be largely benefited due to this major component and system design ideas of 'Smart Power' technologies. The contribution of nano scale power electronics would be realized in various fields like switching devices, electromechanical systems and quantum science. Such a sophisticated technology will have great impact on the modernization of robotics; space systems, automotive systems and many other fields. The highly emerging field of nanomedicine according to specialists would bring a dramatic revolution in the present century. However nanomedicine is nothing but an integration of biology, medicine and technology. Thermoelectric materials as been referred earlier also are used in case of implantable medical equipments for generation of electric power sufficient for those equipments.

LTCC magnetic components for high density power converter

NASA Astrophysics Data System (ADS)

Lebourgeois, Richard; Labouré, Eric; Lembeye, Yves; Ferrieux, Jean-Paul

2018-04-01

This paper deals with multilayer magnetic components for power electronics application and specifically for high frequency switching. New formulations based on nickel-zinc-copper spinel ferrites were developed for high power and high frequency applications. These ferrites can be sintered at low temperature (around 900°C) which makes them compatible with the LTCC (Low Temperature Co-fired Ceramics) technology. Metallic parts of silver or gold can be fully integrated inside the ferrite while guaranteeing the integrity of both the ferrite and the metal. To make inductors or transformers with the required properties, it is mandatory to have nonmagnetic parts between the turns of the winding. Then it is essential to find a dielectric material, which can be co-sintered both with the ferrite and the metal. We will present the solution we found to this problem and we will describe the results we obtained for a multilayer co-sintered transformer. We will see that these new components have good performance compared with the state of the art and are very promising for developing high density switching mode power supplies.

Scattering volume in the collective Thomson scattering measurement using high power gyrotron in the LHD

NASA Astrophysics Data System (ADS)

Kubo, S.; Nishiura, M.; Tanaka, K.; Moseev, D.; Ogasawara, S.; Shimozuma, T.; Yoshimura, Y.; Igami, H.; Takahashi, H.; Tsujimura, T. I.; Makino, R.

2016-06-01

High-power gyrotrons prepared for the electron cyclotron heating at 77 GHz has been used for a collective Thomson scattering (CTS) study in LHD. Due to the difficulty in removing fundamental and/or second harmonic resonance in the viewing line of sight, the subtraction of the background ECE from measured signal was performed by modulating the probe beam power from a gyrotron. The separation of the scattering component from the background has been performed successfully taking into account the response time difference between both high-energy and bulk components. The other separation was attempted by fast scanning the viewing beam across the probing beam. It is found that the intensity of the scattered spectrum corresponding to the bulk and high energy components were almost proportional to the calculated scattering volume in the relatively low density region, while appreciable background scattered component remains even in the off volume in some high density cases. The ray-trace code TRAVIS is used to estimate the change in the scattering volume due to probing and receiving beam deflection effect.

Microfluidic stretchable RF electronics.

PubMed

Cheng, Shi; Wu, Zhigang

2010-12-07

Stretchable electronics is a revolutionary technology that will potentially create a world of radically different electronic devices and systems that open up an entirely new spectrum of possibilities. This article proposes a microfluidic based solution for stretchable radio frequency (RF) electronics, using hybrid integration of active circuits assembled on flex foils and liquid alloy passive structures embedded in elastic substrates, e.g. polydimethylsiloxane (PDMS). This concept was employed to implement a 900 MHz stretchable RF radiation sensor, consisting of a large area elastic antenna and a cluster of conventional rigid components for RF power detection. The integrated radiation sensor except the power supply was fully embedded in a thin elastomeric substrate. Good electrical performance of the standalone stretchable antenna as well as the RF power detection sub-module was verified by experiments. The sensor successfully detected the RF radiation over 5 m distance in the system demonstration. Experiments on two-dimensional (2D) stretching up to 15%, folding and twisting of the demonstrated sensor were also carried out. Despite the integrated device was severely deformed, no failure in RF radiation sensing was observed in the tests. This technique illuminates a promising route of realizing stretchable and foldable large area integrated RF electronics that are of great interest to a variety of applications like wearable computing, health monitoring, medical diagnostics, and curvilinear electronics.

Solid state microelectronics tolerant to radiation and high temperature. [JFET thick film hybrids

NASA Technical Reports Server (NTRS)

Draper, B. L.; Palmer, D. W.

1981-01-01

The 300 C electronics technology based on JFET thick film hybrids was tested up to 10 to the 9th power rad gamma (Si) and 10 to the 15th power neutrons/sq cm. Circuits and individual components from this technology all survived this total dose although some devices required 1 hour of annealing at 200 or 300 C to regain functionality. This technology used with real time annealing should function to levels greater than 10 to the 10th power rad gamma and 10 to the 16th power n/sq cm.

Instrument Packages for the Cold, Dark, High Radiation Environments

NASA Technical Reports Server (NTRS)

Clark, P. E.; Millar, P. S.; Yeh, P. S.; Beamna, B.; Brigham, D.; Feng, S.

2011-01-01

We are developing a small cold temperature instrument package concept that integrates a cold temperature power system and radhard ultra low temperature ultra low power electronics components and power supplies now under development into a cold temperature surface operational version of a planetary surface instrument package. We are already in the process of developing a lower power lower tem-perature version for an instrument of mutual interest to SMD and ESMD to support the search for volatiles (the mass spectrometer VAPoR, Volatile Analysis by Pyrolysis of Regolith) both as a stand alone instrument and as part of an environmental monitoring package.

Engineering of beam direct conversion for a 120-kV, 1-MW ion beam

NASA Technical Reports Server (NTRS)

Barr, W. L.; Doggett, J. N.; Hamilton, G. W.; Kinney, J. D.; Moir, R. W.

1977-01-01

Practical systems for beam direct conversion are required to recover the energy from ion beams at high efficiency and at very high beam power densities in the environment of a high-power neutral-injection system. Such an experiment is now in progress using a 120-kV beam with a maximum total current of 20 A. After neutralization, the H(+) component to be recovered will have a power of approximately 1 MW. A system testing these concepts has been designed and tested at 15 kV, 2 kW in preparation for the full-power tests. The engineering problems involved in the full-power tests affect electron suppression, gas pumping, voltage holding, diagnostics, and measurement conditions. Planning for future experiments at higher power includes the use of cryopumping and electron suppression by a magnetic field rather than by an electrostatic field. Beam direct conversion for large fusion experiments and reactors will save millions of dollars in the cost of power supplies and electricity and will dispose of the charged beam under conditions that may not be possible by other techniques.

Effect of power shape on energy extraction from microbial fuel cell

NASA Astrophysics Data System (ADS)

Alaraj, Muhannad; Feng, Shuo; Roane, Timberley M.; Park, Jae-Do

2017-10-01

Microbial fuel cells (MFCs) generate renewable energy in the form of direct current (DC) power. Harvesting energy from MFCs started with passive components such as resistors and capacitors, then charge pumps were introduced with some more advantages. Power electronics converters were later preferred due to their higher efficiency and controllability; however, they introduce high frequency current ripple due to their high frequency switching. In this paper, the effect of shape of power extraction on MFC performance was investigated using three types of current shapes: continuous, square-wave, and triangular-wave. Simultaneously, chemical parameters, such as pH, dissolved oxygen, electrical conductivity, and redox potential, in the anode chamber were monitored to see how these parameters change with the shape of the electrical power extraction. Results showed that the shape of the extracted current did not have a substantial effect on the MFC life span, output power, and energy extraction, nor on the chemical parameters. The outcome of this study provided insight for the electrical impact by power electronics converters on some microbial and chemical aspects of an MFC system.

The Japanese Positron Factory

NASA Astrophysics Data System (ADS)

Okada, S.; Sunaga, H.; Kaneko, H.; Takizawa, H.; Kawasuso, A.; Yotsumoto, K.; Tanaka, R.

1999-06-01

The Positron Factory has been planned at Japan Atomic Energy Research Institute (JAERI). The factory is expected to produce linac-based monoenergetic positron beams having world-highest intensities of more than 1010e+/sec, which will be applied for R&D of materials science, biotechnology and basic physics & chemistry. In this article, results of the design studies are demonstrated for the following essential components of the facilities: 1) Conceptual design of a high-power electron linac with 100 MeV in beam energy and 100 kW in averaged beam power, 2) Performance tests of the RF window in the high-power klystron and of the electron beam window, 3) Development of a self-driven rotating electron-to-positron converter and the performance tests, 4) Proposal of multi-channel beam generation system for monoenergetic positrons, with a series of moderator assemblies based on a newly developed Monte Carlo simulation and the demonstrative experiment, 5) Proposal of highly efficient moderator structures, 6) Conceptual design of a local shield to suppress the surrounding radiation and activation levels.

Monitoring of Vital Signs with Flexible and Wearable Medical Devices.

PubMed

Khan, Yasser; Ostfeld, Aminy E; Lochner, Claire M; Pierre, Adrien; Arias, Ana C

2016-06-01

Advances in wireless technologies, low-power electronics, the internet of things, and in the domain of connected health are driving innovations in wearable medical devices at a tremendous pace. Wearable sensor systems composed of flexible and stretchable materials have the potential to better interface to the human skin, whereas silicon-based electronics are extremely efficient in sensor data processing and transmission. Therefore, flexible and stretchable sensors combined with low-power silicon-based electronics are a viable and efficient approach for medical monitoring. Flexible medical devices designed for monitoring human vital signs, such as body temperature, heart rate, respiration rate, blood pressure, pulse oxygenation, and blood glucose have applications in both fitness monitoring and medical diagnostics. As a review of the latest development in flexible and wearable human vitals sensors, the essential components required for vitals sensors are outlined and discussed here, including the reported sensor systems, sensing mechanisms, sensor fabrication, power, and data processing requirements. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Energy efficiency evaluation of a stationary lithium-ion battery container storage system via electro-thermal modeling and detailed component analysis

DOE PAGES

Schimpe, Michael; Naumann, Maik; Truong, Nam; ...

2017-11-08

Energy efficiency is a key performance indicator for battery storage systems. A detailed electro-thermal model of a stationary lithium-ion battery system is developed and an evaluation of its energy efficiency is conducted. The model offers a holistic approach to calculating conversion losses and auxiliary power consumption. Sub-models for battery rack, power electronics, thermal management as well as the control and monitoring components are developed and coupled to a comprehensive model. The simulation is parametrized based on a prototype 192 kWh system using lithium iron phosphate batteries connected to the low voltage grid. The key loss mechanisms are identified, thoroughly analyzedmore » and modeled. Generic profiles featuring various system operation modes are evaluated to show the characteristics of stationary battery systems. Typically the losses in the power electronics outweigh the losses in the battery at low power operating points. The auxiliary power consumption dominates for low system utilization rates. For estimation of real-world performance, the grid applications Primary Control Reserve, Secondary Control Reserve and the storage of surplus photovoltaic power are evaluated. Conversion round-trip efficiency is in the range of 70-80%. Finally, overall system efficiency, which also considers system power consumption, is 8-13 percentage points lower for Primary Control Reserve and the photovoltaic-battery application. However, for Secondary Control Reserve, the total round-trip efficiency is found to be extremely low at 23% due to the low energy throughput of this application type.« less

Energy efficiency evaluation of a stationary lithium-ion battery container storage system via electro-thermal modeling and detailed component analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schimpe, Michael; Naumann, Maik; Truong, Nam

Energy efficiency is a key performance indicator for battery storage systems. A detailed electro-thermal model of a stationary lithium-ion battery system is developed and an evaluation of its energy efficiency is conducted. The model offers a holistic approach to calculating conversion losses and auxiliary power consumption. Sub-models for battery rack, power electronics, thermal management as well as the control and monitoring components are developed and coupled to a comprehensive model. The simulation is parametrized based on a prototype 192 kWh system using lithium iron phosphate batteries connected to the low voltage grid. The key loss mechanisms are identified, thoroughly analyzedmore » and modeled. Generic profiles featuring various system operation modes are evaluated to show the characteristics of stationary battery systems. Typically the losses in the power electronics outweigh the losses in the battery at low power operating points. The auxiliary power consumption dominates for low system utilization rates. For estimation of real-world performance, the grid applications Primary Control Reserve, Secondary Control Reserve and the storage of surplus photovoltaic power are evaluated. Conversion round-trip efficiency is in the range of 70-80%. Finally, overall system efficiency, which also considers system power consumption, is 8-13 percentage points lower for Primary Control Reserve and the photovoltaic-battery application. However, for Secondary Control Reserve, the total round-trip efficiency is found to be extremely low at 23% due to the low energy throughput of this application type.« less

On the origin of X-ray spectra in luminous blazars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sikora, Marek; Janiak, Mateusz; Nalewajko, Krzysztof

2013-11-26

Gamma-ray luminosities of some quasar-associated blazars imply jet powers reaching values comparable to the accretion power even if assuming very strong Doppler boosting and very high efficiency of gamma-ray production. With much lower radiative efficiencies of protons than of electrons, and the recent reports of very strong coupling of electrons with shock-heated protons indicated by particle-in-cell simulations, the leptonic models seem to be strongly favored over the hadronic ones. However, the electron-proton coupling combined with the external-radiation-Compton (ERC) models of gamma-ray production in leptonic models predict extremely hard X-ray spectra, with energy indices α x ~ 0. This is inconsistentmore » with the observed 2-10 keV slopes of blazars, which cluster around α x ~ 0.6. This problem can be resolved by assuming that electrons can be efficiently cooled down radiatively to non-relativistic energies, or that blazar spectra are entirely dominated by the synchrotron self-Compton (SSC) component up to at least 10 keV. Here, we show that the required cooling can be sufficiently efficient only at distances r < 0.03 pc. SSC spectra, on the other hand, can be produced roughly co-spatially with the observed synchrotron and ERC components, which are most likely located roughly at a parsec scale. We show that the dominant SSC component can also be produced much further than the dominant synchrotron and ERC components, at distances of gsim 10 pc. Hence, depending on the spatial distribution of the energy dissipation along the jet, one may expect to see γ-ray/optical events with either correlated or uncorrelated X-rays. In all cases the number of e +e – pairs per proton is predicted to be very low. The direct verification of the proposed SSC scenario, and particularly the question of the co-spatiality of the SSC component with other spectral components, requires sensitive observations in the hard X-ray band. Lastly, this is now possible with the deployment of the NuSTAR satellite, providing the required sensitivity to monitor the details of the hard X-ray spectra of blazars in the range where the ERC component is predicted to start dominating over the SSC component.« less

Radiation Shielding Study of Advanced Data and Power Management Systems (ADPMS) Housing Using Geant4

NASA Astrophysics Data System (ADS)

Garcia, F.; Kurvinen, K.; Brander, T.; Orava, R.; Heino, J.; Virtanen, A.; Kettunen, H.; Tenhunen, M.

2008-02-01

A design goal for current space system is to reduce the mass used to enclose components of the spacecraft. One potential target is to reduce the mass of electronics and its housings. The use of composite materials, especially CFRP (Carbon Fiber Reinforced Plastic) is a well known and vastly used approach to mass reduction. A design goal, cost reduction, has increased the use of commercial (non-space qualified) electronics. These commercial circuits and other components cannot tolerate as high radiation levels as space qualified components. Therefore, the use of standard electronics components poses a challenge in terms of the radiation protection capability of the ADPMS housings. The main goal of this study is to provide insight on the radiation shielding protection produced by different configurations of CFRP tungsten laminates of epoxies and cyanate esters and then to compare them to the protection given by the commonly used aluminum. For a spacecraft operating in LEO and MEO orbits the main components of the space radiation environment are energetic electrons and protons, therefore in our study we will compare the experimental and simulation results of the radiation attenuation of different types of laminates for those particles. At the same time the experimental data has been used to validate the Geant4 model of the laminates, which can be used for future optimizations of the laminate structures.

Spatial distribution of the electron component parameters in the nitrogen plasma of a low-pressure electrode microwave Discharge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lebedev, Yu. A., E-mail: lebedev@ips.ac.ru; Krashevskaya, G. V., E-mail: krashevskaya-gv@mail.ru; Gogoleva, M. A., E-mail: masha-g@list.ru

2016-01-15

Spatial distributions of charged particle concentration, electron temperature, and DC potential in an electrode microwave discharge in nitrogen at a pressure of 1 Torr have been measured using the double electric probe method. It has been shown that, near the electrode/antenna, the charged particle concentration exceeds a critical value. The concentration and heterogeneity of the discharge increase with increasing microwave power.

Vibrational spectroscopy in the electron microscope.

PubMed

Krivanek, Ondrej L; Lovejoy, Tracy C; Dellby, Niklas; Aoki, Toshihiro; Carpenter, R W; Rez, Peter; Soignard, Emmanuel; Zhu, Jiangtao; Batson, Philip E; Lagos, Maureen J; Egerton, Ray F; Crozier, Peter A

2014-10-09

Vibrational spectroscopies using infrared radiation, Raman scattering, neutrons, low-energy electrons and inelastic electron tunnelling are powerful techniques that can analyse bonding arrangements, identify chemical compounds and probe many other important properties of materials. The spatial resolution of these spectroscopies is typically one micrometre or more, although it can reach a few tens of nanometres or even a few ångströms when enhanced by the presence of a sharp metallic tip. If vibrational spectroscopy could be combined with the spatial resolution and flexibility of the transmission electron microscope, it would open up the study of vibrational modes in many different types of nanostructures. Unfortunately, the energy resolution of electron energy loss spectroscopy performed in the electron microscope has until now been too poor to allow such a combination. Recent developments that have improved the attainable energy resolution of electron energy loss spectroscopy in a scanning transmission electron microscope to around ten millielectronvolts now allow vibrational spectroscopy to be carried out in the electron microscope. Here we describe the innovations responsible for the progress, and present examples of applications in inorganic and organic materials, including the detection of hydrogen. We also demonstrate that the vibrational signal has both high- and low-spatial-resolution components, that the first component can be used to map vibrational features at nanometre-level resolution, and that the second component can be used for analysis carried out with the beam positioned just outside the sample--that is, for 'aloof' spectroscopy that largely avoids radiation damage.

Compact Circuit Preprocesses Accelerometer Output

NASA Technical Reports Server (NTRS)

Bozeman, Richard J., Jr.

1993-01-01

Compact electronic circuit transfers dc power to, and preprocesses ac output of, accelerometer and associated preamplifier. Incorporated into accelerometer case during initial fabrication or retrofit onto commercial accelerometer. Made of commercial integrated circuits and other conventional components; made smaller by use of micrologic and surface-mount technology.

75 FR 62436 - Notice of Issuance of Regulatory Guide

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-08

... Power Plants,'' includes in its scope safety- related structures, systems, and components (SSCs) that... monitor the effectiveness of maintenance for protective coatings within its scope (as discrete systems or... and Management System (ADAMS) under Accession No. ML102230359. Electronic copies of Regulatory Guide 1...

Robust, Radiation Tolerant Command and Data Handling and Power System Electronics for SmallSats

NASA Technical Reports Server (NTRS)

Nguyen, Hanson Cao; Fraction, James

2018-01-01

In today's budgetary environment, there is significant interest within the National Aeronautics and Space Administration (NASA) to enable small robotic science missions that can be executed faster and cheaper than previous larger missions. To help achieve this, focus has shifted from using exclusively radiation-tolerant or radiation-hardened parts to using more commercial-off-the-shelf (COTS) components for NASA small satellite missions that can last at least one year in orbit. However, there are some portions of a spacecraft's avionics, such as the Command and Data Handling (C&DH) subsystem and the Power System Electronics (PSE) that need to have a higher level of reliability that goes beyond what is attainable with currently available COTS parts. While there are a number of COTS components that can withstand a total ionizing dose (TID) of tens or hundreds of kilorads, there is still a great deal of concern about tolerance to and mitigation of single-event effects (SEE).

KENNEDY SPACE CENTER, FLA. - During power-up of the orbiter Discovery in the Orbiter Processing Facility, a technician moves a switch. Discovery has been undergoing Orbiter Major Modifications in the past year, ranging from wiring, control panels and black boxes to gaseous and fluid systems tubing and components. These systems were deserviced, disassembled, inspected, modified, reassembled, checked out and reserviced, as were most other systems onboard. The work includes the installation of the Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.”

NASA Image and Video Library

2003-08-27

KENNEDY SPACE CENTER, FLA. - During power-up of the orbiter Discovery in the Orbiter Processing Facility, a technician moves a switch. Discovery has been undergoing Orbiter Major Modifications in the past year, ranging from wiring, control panels and black boxes to gaseous and fluid systems tubing and components. These systems were deserviced, disassembled, inspected, modified, reassembled, checked out and reserviced, as were most other systems onboard. The work includes the installation of the Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.”

KENNEDY SPACE CENTER, FLA. - During power-up of the orbiter Discovery in the Orbiter Processing Facility, a technician turns on a switch. Discovery has been undergoing Orbiter Major Modifications in the past year, ranging from wiring, control panels and black boxes to gaseous and fluid systems tubing and components. These systems were deserviced, disassembled, inspected, modified, reassembled, checked out and reserviced, as were most other systems onboard. The work includes the installation of the Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.”

NASA Image and Video Library

2003-08-27

KENNEDY SPACE CENTER, FLA. - During power-up of the orbiter Discovery in the Orbiter Processing Facility, a technician turns on a switch. Discovery has been undergoing Orbiter Major Modifications in the past year, ranging from wiring, control panels and black boxes to gaseous and fluid systems tubing and components. These systems were deserviced, disassembled, inspected, modified, reassembled, checked out and reserviced, as were most other systems onboard. The work includes the installation of the Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.”

Flexible and stretchable microbial fuel cells with modified conductive and hydrophilic textile.

PubMed

Pang, Sumiao; Gao, Yang; Choi, Seokheun

2018-02-15

We built a flexible, stretchable microbial fuel cell (MFC) by laminating two functional components: a bioanode textile with a conductive and hydrophilic polymer coating and a solid-state cathode textile loaded with silver oxide. The textile MFC used Pseudomonas aeruginosa PAO1 as a biocatalyst to generate the maximum power and current density of 1.0µW/cm 2 and 6.3µA/cm 2 , respectively, which are comparable with or even higher than other flexible MFCs such as paper-based devices (~ a few µW/cm 2 ). Additionally, the textile MFC generated consistent power even with repeated 70 cycles of 50% stretching. A simple batch fabrication method simultaneously produced 20 individual 2cm × 2cm devices by using brushing, spraying, ironing, and computerized sewing, a process that will revolutionize the mass production of textile MFCs. This achievement is scientifically meaningful because developing textile MFCs requires integration of both electronic and fluidic components into the textile three-dimensionally. This flexible and stretchable energy harvesting device is expected to be easily integrated with the next generation stretchable electronics for realizing low-power, stand-alone, self-sustainable systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Circuit for Communication over DC Power Line Using High Temperature Electronics

NASA Technical Reports Server (NTRS)

Krasowski, Michael J. (Inventor); Prokop, Norman F. (Inventor)

2014-01-01

A high temperature communications circuit includes a power conductor for concurrently conducting electrical energy for powering circuit components and transmitting a modulated data signal, and a demodulator for demodulating the data signal and generating a serial bit stream based on the data signal. The demodulator includes an absolute value amplifier for conditionally inverting or conditionally passing a signal applied to the absolute value amplifier. The absolute value amplifier utilizes no diodes to control the conditional inversion or passing of the signal applied to the absolute value amplifier.

Thermoelectric Devices Cool, Power Electronics

NASA Technical Reports Server (NTRS)

2009-01-01

Nextreme Thermal Solutions Inc., based in Research Triangle Park, North Carolina, licensed thermoelectric technology from NASA s Jet Propulsion Laboratory. This has allowed the company to develop cutting edge, thin-film thermoelectric coolers that effective remove heat generated by increasingly powerful and tightly packed microchip components. These solid-state coolers are ideal solutions for applications like microprocessors, laser diodes, LEDs, and even potentially for cooling the human body. Nextreme s NASA technology has also enabled the invention of thermoelectric generators capable of powering technologies like medical implants and wireless sensor networks.

Reliability of hybrid microcircuit discrete components

NASA Technical Reports Server (NTRS)

Allen, R. V.

1972-01-01

Data accumulated during 4 years of research and evaluation of ceramic chip capacitors, ceramic carrier mounted active devices, beam-lead transistors, and chip resistors are presented. Life and temperature coefficient test data, and optical and scanning electron microscope photographs of device failures are presented and the failure modes are described. Particular interest is given to discrete component qualification, power burn-in, and procedures for testing and screening discrete components. Burn-in requirements and test data will be given in support of 100 percent burn-in policy on all NASA flight programs.

High-Temperature High-Power Packaging Techniques for HEV Traction Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barlow, F.D.; Elshabini, A.

A key issue associated with the wider adoption of hybrid-electric vehicles (HEV) and plug in hybrid-electric vehicles (PHEV) is the implementation of the power electronic systems that are required in these products [1]. To date, many consumers find the adoption of these technologies problematic based on a financial analysis of the initial cost versus the savings available from reduced fuel consumption. Therefore, one of the primary industry goals is the reduction in the price of these vehicles relative to the cost of traditional gasoline powered vehicles. Part of this cost reduction must come through optimization of the power electronics requiredmore » by these vehicles. In addition, the efficiency of the systems must be optimized in order to provide the greatest range possible. For some drivers, any reduction in the range associated with a potential HEV or PHEV solution in comparison to a gasoline powered vehicle represents a significant barrier to adoption and the efficiency of the power electronics plays an important role in this range. Likewise, high efficiencies are also important since lost power further complicates the thermal management of these systems. Reliability is also an important concern since most drivers have a high level of comfort with gasoline powered vehicles and are somewhat reluctant to switch to a less proven technology. Reliability problems in the power electronics or associated components could not only cause a high warranty cost to the manufacturer, but may also taint these technologies in the consumer's eyes. A larger vehicle offering in HEVs is another important consideration from a power electronics point of view. A larger vehicle will need more horsepower, or a larger rated drive. In some ways this will be more difficult to implement from a cost and size point of view. Both the packaging of these modules and the thermal management of these systems at competitive price points create significant challenges. One way in which significant cost reduction of these systems could be achieved is through the use of a single coolant loop for both the power electronics as well as the internal combustion engine (ICE) [2]. This change would reduce the complexity of the cooling system which currently relies on two loops to a single loop [3]. However, the current nominal coolant temperature entering these inverters is 65 C [3], whereas a normal ICE coolant temperature would be much higher at approximately 100 C. This change in coolant temperature significantly increases the junction temperatures of the devices and creates a number of challenges for both device fabrication and the assembly of these devices into inverters and converters for HEV and PHEV applications. With this change in mind, significant progress has been made on the use of SiC devices for inverters that can withstand much higher junction temperatures than traditional Si based inverters [4,5,6]. However, a key problem which the single coolant loop and high temperature devices is the effective packaging of these devices and related components into a high temperature inverter. The elevated junction temperatures that exist in these modules are not compatible with reliable inverters based on existing packaging technology. This report seeks to provide a literature survey of high temperature packaging and to highlight the issues related to the implementation of high temperature power electronic modules for HEV and PHEV applications. For purposes of discussion, it will be assumed in this report that 200 C is the targeted maximum junction temperature.« less

ESRDC - Designing and Powering the Future Fleet

DTIC Science & Technology

2018-02-22

Awards Management 301 Main Street University of South Carolina Columbia, SC 29208 1600 Hampton St, Suite 414 Phone: 803-777-7890 Columbia, SC 29208... managing short circuit faults in MVDC Systems, and 5) modeling of SiC-based electronic power converters to support accurate scalable models in S3D...Research in advanced thermal management followed three tracks. We developed models of thermal system components that are suitable for use in early stage

The stationary non-equilibrium plasma of cosmic-ray electrons and positrons

NASA Astrophysics Data System (ADS)

Tomaschitz, Roman

2016-06-01

The statistical properties of the two-component plasma of cosmic-ray electrons and positrons measured by the AMS-02 experiment on the International Space Station and the HESS array of imaging atmospheric Cherenkov telescopes are analyzed. Stationary non-equilibrium distributions defining the relativistic electron-positron plasma are derived semi-empirically by performing spectral fits to the flux data and reconstructing the spectral number densities of the electronic and positronic components in phase space. These distributions are relativistic power-law densities with exponential cutoff, admitting an extensive entropy variable and converging to the Maxwell-Boltzmann or Fermi-Dirac distributions in the non-relativistic limit. Cosmic-ray electrons and positrons constitute a classical (low-density high-temperature) plasma due to the low fugacity in the quantized partition function. The positron fraction is assembled from the flux densities inferred from least-squares fits to the electron and positron spectra and is subjected to test by comparing with the AMS-02 flux ratio measured in the GeV interval. The calculated positron fraction extends to TeV energies, predicting a broad spectral peak at about 1 TeV followed by exponential decay.

Technology of fast spark gaps

NASA Astrophysics Data System (ADS)

Standler, Ronald B.

1989-09-01

To protect electronic systems from the effects of electromagnetic pulse (EMP) form nuclear weapons and high-power microwave (HPM) weapons, it is desirable to have fast responding protection components. The gas-filled spark gap appears to be an attractive protection component, except that it can be slow to conduct under certain conditions. This report reviews the literature and presents ideas for construction of a spark gap that will conduct in less than one nanosecond. The key concept to making a fast-responding spark gap is to produce a large number of free electrons quickly. Seven different mechanisms for production of free electrons are reviewed, and several that are relevant to miniature spark gaps for protective applications are discussed in detail. These mechanisms include: inclusion of radioactive materials, photoelectric effect, secondary electrode emission from the anode, and field emission from the cathode.

STATISTICAL STUDY of HARD X-RAY SPECTRAL CHARACTERISTICS OF SOLAR FLARES

NASA Astrophysics Data System (ADS)

Alaoui, M.; Krucker, S.; Saint-Hilaire, P.; Lin, R. P.

2009-12-01

We investigate the spectral characteristics of 75 solar flares at the hard X-ray peak time observed by RHESSI (Ramaty High Energy Solar Spectroscopic Imager) in the energy range 12-150keV. At energies above 40keV, the Hard X-ray emission is mostly produced by bremsstrahlung of suprathermal electrons as they interact with the ambient plasma in the chromosphere. The observed photon spectra therefore provide diagnostics of electron acceleration processes in Solar flares. We will present statistical results of spectral fitting using two models: a broken power law plus a thermal component which is a direct fit of the photon spectrum and a thick target model plus a thermal component which is a fit of the photon spectra with assumptions on the electrons emitting bremsstrahlung in the thick target approximation.

Microsupercapacitors as miniaturized energy-storage components for on-chip electronics

NASA Astrophysics Data System (ADS)

Kyeremateng, Nana Amponsah; Brousse, Thierry; Pech, David

2017-01-01

The push towards miniaturized electronics calls for the development of miniaturized energy-storage components that can enable sustained, autonomous operation of electronic devices for applications such as wearable gadgets and wireless sensor networks. Microsupercapacitors have been targeted as a viable route for this purpose, because, though storing less energy than microbatteries, they can be charged and discharged much more rapidly and have an almost unlimited lifetime. In this Review, we discuss the progress and the prospects of integrated miniaturized supercapacitors. In particular, we discuss their power performances and emphasize the need of a three-dimensional design to boost their energy-storage capacity. This is obtainable, for example, through self-supported nanostructured electrodes. We also critically evaluate the performance metrics currently used in the literature to characterize microsupercapacitors and offer general guidelines to benchmark performances towards prospective applications.

Microsupercapacitors as miniaturized energy-storage components for on-chip electronics.

PubMed

Kyeremateng, Nana Amponsah; Brousse, Thierry; Pech, David

2017-01-01

The push towards miniaturized electronics calls for the development of miniaturized energy-storage components that can enable sustained, autonomous operation of electronic devices for applications such as wearable gadgets and wireless sensor networks. Microsupercapacitors have been targeted as a viable route for this purpose, because, though storing less energy than microbatteries, they can be charged and discharged much more rapidly and have an almost unlimited lifetime. In this Review, we discuss the progress and the prospects of integrated miniaturized supercapacitors. In particular, we discuss their power performances and emphasize the need of a three-dimensional design to boost their energy-storage capacity. This is obtainable, for example, through self-supported nanostructured electrodes. We also critically evaluate the performance metrics currently used in the literature to characterize microsupercapacitors and offer general guidelines to benchmark performances towards prospective applications.

Electrical Prototype Power Processor for the 30-cm Mercury electric propulsion engine

NASA Technical Reports Server (NTRS)

Biess, J. J.; Frye, R. J.

1978-01-01

An Electrical Prototpye Power Processor has been designed to the latest electrical and performance requirements for a flight-type 30-cm ion engine and includes all the necessary power, command, telemetry and control interfaces for a typical electric propulsion subsystem. The power processor was configured into seven separate mechanical modules that would allow subassembly fabrication, test and integration into a complete power processor unit assembly. The conceptual mechanical packaging of the electrical prototype power processor unit demonstrated the relative location of power, high voltage and control electronic components to minimize electrical interactions and to provide adequate thermal control in a vacuum environment. Thermal control was accomplished with a heat pipe simulator attached to the base of the modules.

Electrical design of payload G-534: The Pool Boiling Experiment

NASA Technical Reports Server (NTRS)

Francisco, David R.

1992-01-01

Payload G-534, the Pool Boiling Experiment (PBE), is a Get Away Special that is scheduled to fly on the shuttle in 1992. This paper will give a brief overall description of the experiment with the main discussion being the electrical design with a detailed description of the power system and interface to the GAS electronics. The batteries used and their interface to the experiment Power Control Unit (PCU) and GAS electronics will be examined. The design philosophy for the PCU will be discussed in detail. The criteria for selection of fuses, relays, power semiconductors and other electrical components along with grounding and shielding policy for the entire experiment will be presented. The intent of this paper is to discuss the use of military tested parts and basic design guidelines to build a quality experiment for minimal additional cost.

Effect of Voltage Level on Power System Design for Solar Electric Propulsion Missions

NASA Technical Reports Server (NTRS)

Kerslake, Thomas W.

2003-01-01

This paper presents study results quantifying the benefits of higher voltage, electric power system designs for a typical solar electric propulsion spacecraft Earth orbiting mission. A conceptual power system architecture was defined and design points were generated for system voltages of 28-V, 50-V, 120-V, and 300-V using state-of-the-art or advanced technologies. A 300-V 'direct-drive' architecture was also analyzed to assess the benefits of directly powering the electric thruster from the photovoltaic array without up-conversion. Fortran and spreadsheet computational models were exercised to predict the performance and size power system components to meet spacecraft mission requirements. Pertinent space environments, such as electron and proton radiation, were calculated along the spiral trajectory. In addition, a simplified electron current collection model was developed to estimate photovoltaic array losses for the orbital plasma environment and that created by the thruster plume. The secondary benefits of power system mass savings for spacecraft propulsion and attitude control systems were also quantified. Results indicate that considerable spacecraft wet mass savings were achieved by the 300-V and 300-V direct-drive architectures.

30 CFR 250.1630 - Safety-system testing and records.

Code of Federal Regulations, 2010 CFR

2010-07-01

... AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Sulphur Operations § 250.1630 Safety... components, and the following: (1) Safety relief valves on the natural gas feed system for power plant... source. (2) The following safety devices (excluding electronic pressure transmitters and level sensors...

75 FR 45159 - Delphi Steering Currently Known as Nexteer Automotive Including On-Site Leased Workers From Acro...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-02

..., Inc., Continental, Inc., Dynamic Corp., G-Tech Professional Staffing, Inc., Globaledgetechnologies... Corporation, Aerotek, Inc., Continental, Inc., Dynamic Corp., G-Tech Professional Staffing, Inc., Globaledge... steering systems and components such as steering columns, gears, pumps and electronic power steering...

Advanced Integrated Traction System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greg Smith; Charles Gough

2011-08-31

The United States Department of Energy elaborates the compelling need for a commercialized competitively priced electric traction drive system to proliferate the acceptance of HEVs, PHEVs, and FCVs in the market. The desired end result is a technically and commercially verified integrated ETS (Electric Traction System) product design that can be manufactured and distributed through a broad network of competitive suppliers to all auto manufacturers. The objectives of this FCVT program are to develop advanced technologies for an integrated ETS capable of 55kW peak power for 18 seconds and 30kW of continuous power. Additionally, to accommodate a variety of automotivemore » platforms the ETS design should be scalable to 120kW peak power for 18 seconds and 65kW of continuous power. The ETS (exclusive of the DC/DC Converter) is to cost no more than $660 (55kW at $12/kW) to produce in quantities of 100,000 units per year, should have a total weight less than 46kg, and have a volume less than 16 liters. The cost target for the optional Bi-Directional DC/DC Converter is $375. The goal is to achieve these targets with the use of engine coolant at a nominal temperature of 105C. The system efficiency should exceed 90% at 20% of rated torque over 10% to 100% of maximum speed. The nominal operating system voltage is to be 325V, with consideration for higher voltages. This project investigated a wide range of technologies, including ETS topologies, components, and interconnects. Each technology and its validity for automotive use were verified and then these technologies were integrated into a high temperature ETS design that would support a wide variety of applications (fuel cell, hybrids, electrics, and plug-ins). This ETS met all the DOE 2010 objectives of cost, weight, volume and efficiency, and the specific power and power density 2015 objectives. Additionally a bi-directional converter was developed that provides charging and electric power take-off which is the first step towards enabling a smart-grid application. GM under this work assessed 29 technologies; investigated 36 configurations/types power electronics and electric machines, filed 41 invention disclosures; and ensured technology compatibility with vehicle production. Besides the development of a high temperature ETS the development of industrial suppliers took place because of this project. Suppliers of industrial power electronic components are numerous, but there are few that have traction drive knowledge. This makes it difficult to achieve component reliability, durability, and cost requirements necessary of high volume automotive production. The commercialization of electric traction systems for automotive industry requires a strong diverse supplier base. Developing this supplier base is dependent on a close working relationship between the OEM and supplier so that appropriate component requirements can be developed. GM has worked closely with suppliers to develop components for electric traction systems. Components that have been the focus of this project are power modules, capacitors, heavy copper boards, current sensors, and gate drive and controller chip sets. Working with suppliers, detailed component specifications have been developed. Current, voltage, and operation environment during the vehicle drive cycle were evaluated to develop higher resolution/accurate component specifications.« less

The Multiple Gyrotron System on the DIII-D Tokamak

DOE PAGES

Lohr, J.; Anderson, J.; Brambila, R.; ...

2015-08-28

A major component of the versatile heating systems on the DIII-D tokamak is the gyrotron complex. This system routinely operates at 110 GHz with 4.7 MW generated rf power for electron cyclotron heating and current drive. The complex is being upgraded with the addition of new depressed collector potential gyrotrons operating at 117.5 GHz and generating rf power in excess of 1.0 MW each. The long term upgrade plan calls for 10 gyrotrons at the higher frequency being phased in as resources permit, for an injected power near 10 MW. This article presents a summary of the current status ofmore » the DIII-D gyrotron complex, its performance, individual components, testing procedures, operational parameters, plans, and a brief summary of the experiments for which the system is currently being used.« less

Solid-state pulse modulator using Marx generator for a medical linac electron-gun

NASA Astrophysics Data System (ADS)

Lim, Heuijin; Hyeok Jeong, Dong; Lee, Manwoo; Lee, Mujin; Yi, Jungyu; Yang, Kwangmo; Ro, Sung Chae

2016-04-01

A medical linac is used for the cancer treatment and consists of an accelerating column, waveguide components, a magnetron, an electron-gun, a pulse modulator, and an irradiation system. The pulse modulator based on hydrogen thyratron-switched pulse-forming network is commonly used in linac. As the improvement of the high power semiconductors in switching speed, voltage rating, and current rating, an insulated gate bipolar transistor has become the more popular device used for pulsed power systems. We propose a solid-state pulse modulator to generator high voltage by multi-stacked storage-switch stages based on the Marx generator. The advantage of our modulator comes from the use of two semiconductors to control charging and discharging of the storage capacitor at each stage and it allows to generate the pulse with various amplitudes, widths, and shapes. In addition, a gate driver for two semiconductors is designed to reduce the control channels and to protect the circuits. It is developed for providing the pulsed power to a medical linac electron-gun that requires 25 kV and 1 A as the first application. In order to improve the power efficiency and achieve the compactness modulator, a capacitor charging power supply, a Marx pulse generator, and an electron-gun heater isolated transformer are constructed and integrated. This technology is also being developed to extend the high power pulsed system with > 1 MW and also other applications such as a plasma immersed ion implantation and a micro pulse electrostatic precipitator which especially require variable pulse shape and high repetition rate > 1 kHz. The paper describes the design features and the construction of this solid-state pulse modulator. Also shown are the performance results into the linac electron-gun.

Automotive Stirling Engine Mod 1 Design Review, volume 2

NASA Technical Reports Server (NTRS)

1982-01-01

The auxiliaries and the control system for the ASE MOD I: (1) provide the required fuel and air flows for a well controlled combustion process, generating heat to the Stirling cycle; (2) provide a driver acceptable method for controlling the power output of the engine; (3) provide adequate lubrication and cooling water circulation; (4) generate the electric energy required for engine and vehicle operation; (5) provide a driver acceptable method for starting, stopping and monitoring the engine; and (6) provide a guard system, that protects the engine at component or system malfunction. The control principles and the way the different components and sub-systems interact are described as well as the different auxiliaries, the air fuel system, the power control systems and the electronics. The arrangement and location of auxiliaries and other major components are also examined.

Investigation of irradiation effects on highly integrated leading-edge electronic components of diagnostics and control systems for LHD deuterium operation

NASA Astrophysics Data System (ADS)

Ogawa, K.; Nishitani, T.; Isobe, M.; Murata, I.; Hatano, Y.; Matsuyama, S.; Nakanishi, H.; Mukai, K.; Sato, M.; Yokota, M.; Kobuchi, T.; Nishimura, T.; Osakabe, M.

2017-08-01

High-temperature and high-density plasmas are achieved by means of real-time control, fast diagnostic, and high-power heating systems. Those systems are precisely controlled via highly integrated electronic components, but can be seriously affected by radiation damage. Therefore, the effects of irradiation on currently used electronic components should be investigated for the control and measurement of Large Helical Device (LHD) deuterium plasmas. For the precise estimation of the radiation field in the LHD torus hall, the MCNP6 code is used with the cross-section library ENDF B-VI. The geometry is modeled on the computer-aided design. The dose on silicon, which is a major ingredient of electronic components, over nine years of LHD deuterium operation shows that the gamma-ray contribution is dominant. Neutron irradiation tests were performed in the OKTAVIAN at Osaka University and the Fast Neutron Laboratory at Tohoku University. Gamma-ray irradiation tests were performed at the Nagoya University Cobalt-60 irradiation facility. We found that there are ethernet connection failures of programmable logic controller (PLC) modules due to neutron irradiation with a neutron flux of 3  ×  106 cm-2 s-1. This neutron flux is equivalent to that expected at basement level in the LHD torus hall without a neutron shield. Most modules of the PLC are broken around a gamma-ray dose of 100 Gy. This is comparable with the dose in the LHD torus hall over nine years. If we consider the dose only, these components may survive more than nine years. For the safety of the LHD operation, the electronic components in the torus hall have been rearranged.

PREFACE: Spin Electronics

NASA Astrophysics Data System (ADS)

Dieny, B.; Sousa, R.; Prejbeanu, L.

2007-04-01

Conventional electronics has in the past ignored the spin on the electron, however things began to change in 1988 with the discovery of giant magnetoresistance in metallic thin film stacks which led to the development of a new research area, so called spin-electronics. In the last 10 years, spin-electronics has achieved a number of breakthroughs from the point of view of both basic science and application. Materials research has led to several major discoveries: very large tunnel magnetoresistance effects in tunnel junctions with crystalline barriers due to a new spin-filtering mechanism associated with the spin-dependent symmetry of the electron wave functions new magnetic tunnelling barriers leading to spin-dependent tunnelling barrier heights and acting as spin-filters magnetic semiconductors with increasingly high ordering temperature. New phenomena have been predicted and observed: the possibility of acting on the magnetization of a magnetic nanostructure with a spin-polarized current. This effect, due to a transfer of angular momentum between the spin polarized conduction electrons and the local magnetization, can be viewed as the reciprocal of giant or tunnel magnetoresistance. It can be used to switch the magnetization of a magnetic nanostructure or to generate steady magnetic excitations in the system. the possibility of generating and manipulating spin current without charge current by creating non-equilibrium local accumulation of spin up or spin down electrons. The range of applications of spin electronics materials and phenomena is expanding: the first devices based on giant magnetoresistance were the magnetoresistive read-heads for computer disk drives. These heads, introduced in 1998 with current-in plane spin-valves, have evolved towards low resistance tunnel magnetoresistice heads in 2005. Besides magnetic recording technology, these very sensitive magnetoresistive sensors are finding applications in other areas, in particular in biology. magnetic tunnel junctions were introduced as memory elements in new types of non-volatile magnetic memories (MRAM). A first 4Mbit product was launched by Freescale in July 2006. Future generations of memories are being developed by academic groups or companies. the combination of magnetic elements with CMOS components opens a whole new paradigm in hybrid electronic components which can change the common conception of the architecture of complex electronic components with a much tighter integration of logic and memory. the steady magnetic excitations stimulated by spin-transfer might be used in a variety of microwave components provided the output power can be increased. Intense research and development efforts are being aimed at increasing this power by the synchronization of oscillators. The articles compiled in this special issue of Journal of Physics: Condensed Matter, devoted to spin electronics, review these recent developments. All the contributors are greatly acknowledged.

Start Up Application Concerns with Field Programmable Gate Arrays (FPGAs)

NASA Technical Reports Server (NTRS)

Katz, Richard B.

1999-01-01

This note is being published to improve the visibility of this subject, as we continue to see problems surface in designs, as well as to add additional information to the previously published note for design engineers. The original application note focused on designing systems with no single point failures using Actel Field Programmable Gate Arrays (FPGAs) for critical applications. Included in that note were the basic principles of operation of the Actel FPGA and a discussion of potential single-point failures. The note also discussed the issue of startup transients for that class of device. It is unfortunate that we continue to see some design problems using these devices. This note will focus on the startup properties of certain electronic components, in general, and current Actel FPGAs, in particular. Devices that are "power-on friendly" are currently being developed by Actel, as a variant of the new SX series of FPGAs. In the ideal world, electronic components would behave much differently than they do in the real world, The chain, of course, starts with the power supply. Ideally, the voltage will immediately rise to a stable V(sub cc) level, of course, it does not. Aside from practical design considerations, inrush current limits of certain capacitors must be observed and the power supply's output may be intentionally slew rate limited to prevent a large current spike on the system power bus. In any event, power supply rise time may range from less than I msec to 100 msec or more.

Polarization Measurements During Electron Cyclotron Heating Experiments in the DIII-D Tokamak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petty, C.C.; Luce, T.C.; Austin, M.E.

The polarization of the launched electron cyclotron wave has been optimized for coupling to the X-mode by adjusting the inclination of grooved mirrors located in two consecutive mitre bends of the waveguide. The unwanted O-mode component of the launched beam can be positively identified by the difference in the power deposition profiles between X-mode and O-mode. The optimal polarization for X-mode launch is in good agreement with theoretical expectations.

Response of geostationary communications satellite solid-state power amplifiers to high-energy electron fluence

NASA Astrophysics Data System (ADS)

Lohmeyer, Whitney; Carlton, Ashley; Wong, Frankie; Bodeau, Michael; Kennedy, Andrew; Cahoy, Kerri

2015-05-01

The key components in communications satellite payloads are the high-power amplifiers that amplify the received signal so that it can be accurately transmitted to the intended end user. In this study, we examine 26 amplifier anomalies and quantify the high-energy electron environment for periods of time prior to the anomalies. Building on the work of Lohmeyer and Cahoy (2013), we find that anomalies occur at a rate higher than just by chance when the >2 MeV electron fluence accumulated over 14 and 21 days is elevated. To try to understand "why," we model the amplifier subsystem to assess whether the dielectric material in the radio frequency (RF) coaxial cables, which are the most exposed part of the system, is liable to experience electrical breakdown due to internal charging. We find that the accumulated electric field over the 14 and 21 days leading up to the anomalies is high enough to cause the dielectric material in the coax to breakdown. We also find that the accumulated voltages reached are high enough to compromise components in the amplifier system, for example, the direct current (DC) blocking capacitor. An electron beam test using a representative coaxial cable terminated in a blocking capacitor showed that discharges could occur with peak voltages and energies sufficient to damage active RF semiconductor devices.

LH launcher Arcs Formation and Detection on JET

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baranov, Yu. F.; Challis, C. D.; Kirov, K.

2011-12-23

Mechanisms of arc formation have been analyzed and the critical electric fields for the multipactor effect calculated, compared to the experimental values and found to be within the normal operational space of the LH system on JET. It has been shown that the characteristic electron energy (20-1000)eV for the highest multipactor resonances (N = 4-9) are within the limits of secondary electron yield above 1 required for multipactoring. Electrons with these energies provide the highest gas desorption efficiency when hitting the waveguide walls. The effect of higher waveguide modes and magnetic field on the multipactor was also considered. The distributionmore » function for electrons accelerated by LH waves in front of the launcher has been calculated. The field emission currents have been estimated and found to be small. It is proposed that emission of Fel5, 16 lines, which can be obtained with improved diagnostics, could be used to detect arcs that are missed by a protection system based on the reflected power. The reliability and time response of these signals are discussed. A similar technique based on the observation of the emission of low ionized atoms can be used for a fast detection of other undesirable events to avoid sputtering or melting of the plasma facing components such as RF antenna. These techniques are especially powerful if they are based on emission uniquely associated with specific locations and components.« less

Diagnosis of power fade mechanisms in high-power lithium-ion cells

NASA Astrophysics Data System (ADS)

Abraham, D. P.; Liu, J.; Chen, C. H.; Hyung, Y. E.; Stoll, M.; Elsen, N.; MacLaren, S.; Twesten, R.; Haasch, R.; Sammann, E.; Petrov, I.; Amine, K.; Henriksen, G.

Hybrid electric vehicles (HEV) need long-lived high-power batteries as energy storage devices. Batteries based on lithium-ion technology can meet the high-power goals but have been unable to meet HEV calendar-life requirements. As part of the US Department of Energy's Advanced Technology Development (ATD) Program, diagnostic studies are being conducted on 18650-type lithium-ion cells that were subjected to accelerated aging tests at temperatures ranging from 40 to 70 °C. This article summarizes data obtained by gas chromatography, liquid chromatography, electron microscopy, X-ray spectroscopy and electrochemical techniques, and identifies cell components that are responsible for the observed impedance rise and power fade.

1 mm3-sized optical neural stimulator based on CMOS integrated photovoltaic power receiver

NASA Astrophysics Data System (ADS)

Tokuda, Takashi; Ishizu, Takaaki; Nattakarn, Wuthibenjaphonchai; Haruta, Makito; Noda, Toshihiko; Sasagawa, Kiyotaka; Sawan, Mohamad; Ohta, Jun

2018-04-01

In this work, we present a simple complementary metal-oxide semiconductor (CMOS)-controlled photovoltaic power-transfer platform that is suitable for very small (less than or equal to 1-2 mm) electronic devices such as implantable health-care devices or distributed nodes for the Internet of Things. We designed a 1.25 mm × 1.25 mm CMOS power receiver chip that contains integrated photovoltaic cells. We characterized the CMOS-integrated power receiver and successfully demonstrated blue light-emitting diode (LED) operation powered by infrared light. Then, we integrated the CMOS chip and a few off-chip components into a 1-mm3 implantable optogenetic stimulator, and demonstrated the operation of the device.

FY2010 Oak Ridge National Laboratory Annual Progress Report for the Power Electronics and Electric Machinery Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszewski, Mitchell

The U.S. Department of Energy (DOE) and the U.S. Council for Automotive Research (composed of automakers Ford, General Motors, and Chrysler) announced in January 2002 a new cooperative research effort. Known as FreedomCAR (derived from ''Freedom'' and ''Cooperative Automotive Research''), it represents DOE's commitment to developing public-private partnerships to fund high risk, high payoff research into advanced automotive technologies. Efficient fuel cell technology, which uses hydrogen to power automobiles without air pollution, is a very promising pathway to achieve the ultimate vision. The new partnership replaces and builds upon the Partnership for a New Generation of Vehicles initiative that ranmore » from 1993 through 2001. The Oak Ridge National Laboratory's (ORNL's) Advanced Power Electronics and Electric Machines (APEEM) subprogram within the DOE Vehicle Technologies Program (VTP) provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on developing revolutionary new power electronics (PE) and electric motor technologies that will leapfrog current on-the-road technologies. The research and development (R&D) is also aimed at achieving a greater understanding of and improvements in the way the various new components of tomorrow's automobiles will function as a unified system to improve fuel efficiency. In supporting the development of advanced vehicle propulsion systems, the APEEM subprogram has enabled the development of technologies that will significantly improve efficiency, costs, and fuel economy. The APEEM subprogram supports the efforts of the FreedomCAR and Fuel Partnership through a three phase approach intended to: (1) identify overall propulsion and vehicle related needs by analyzing programmatic goals and reviewing industry's recommendations and requirements and then develop the appropriate technical targets for systems, subsystems, and component research and development activities; (2) develop and validate individual subsystems and components, including electric motors and PE; and (3) determine how well the components and subsystems work together in a vehicle environment or as a complete propulsion system and whether the efficiency and performance targets at the vehicle level have been achieved. The research performed under this subprogram will help remove technical and cost barriers to enable the development of technology for use in such advanced vehicles as hybrid electric vehicles (HEVs), plug-in HEVs (PHEVs), battery electric vehicles, and fuel-cell-powered automobiles that meet the goals of the VTP. A key element in making these advanced vehicles practical is providing an affordable electric traction drive system. This will require attaining weight, volume, and cost targets for the PE and electrical machines subsystems of the traction drive system. Areas of development include: (1) novel traction motor designs that result in increased power density and lower cost; (2) inverter technologies involving new topologies to achieve higher efficiency, with the ability to accommodate higher temperature environments while achieving high reliability; (3) converter concepts that use methods of reducing the component count and integrating functionality to decrease size, weight, and cost; (4) new onboard battery charging concepts that result in decreased cost and size; (5) more effective thermal control through innovative packaging technologies; and (6) integrated motor/inverter concepts. ORNL's Power Electronics and Electric Machines Research Program conducts fundamental research, evaluates hardware, and assists in the technical direction of the VTP APEEM subprogram. In this role, ORNL serves on the FreedomCAR Electrical and Electronics Technical Team, evaluates proposals for DOE, and lends its technological expertise to the direction of projects and evaluation of developing technologies. ORNL also executes specific projects for DOE. The following report discusses those projects carried out in FY 2010 and conveys highlights of their accomplishments. Numerous project reviews, technical reports, and papers have been published for these efforts, and they are indicated at the end of each section for readers interested in pursuing details of the work.« less

Prediction and Measurement of Temperature Fields in Silicon-on-Insulator Electronic Circuits

DTIC Science & Technology

1995-08-01

common dimensions are given in Table 1. Almost all of the device power is dissipated in the channel. The electri- cally insulating implanted layer...data. Region or Component substrate Material SOI implanted insulating layers single-crystal silicon, 3 x 1015 boron atoms cm -3 Thermal... implanted silicon-dioxide layer in SOI wafers. The data for each device for varying powers fall near a line originating at P = 0 and T0 = 303 K

X-rays diagnostics of the hot electron energy distribution in the intense laser interaction with metal targets

NASA Astrophysics Data System (ADS)

Kostenko, O. F.; Andreev, N. E.; Rosmej, O. N.

2018-03-01

A two-temperature hot electron energy distribution has been revealed by modeling of bremsstrahlung emission, measured by the radiation attenuation and half-shade methods, and Kα emission from a massive silver cylinder irradiated by a subpicosecond s-polarized laser pulse with a peak intensity of about 2 × 1019 W/cm2. To deduce parameters of the hot electron spectrum, we have developed semi-analytical models of generation and measurements of the x-rays. The models are based on analytical expressions and tabulated data on electron stopping power as well as cross-sections of generation and absorption of the x-rays. The Kα emission from thin silver foils deposited on low-Z substrates, both conducting and nonconducting, has been used to verify the developed models and obtained hot electron spectrum. The obtained temperatures of the colder and hotter electron components are in agreement with the values predicted by kinetic simulations of the cone-guided approach to fast ignition [Chrisman et al., Phys. Plasmas 15, 056309 (2008)]. The temperature of the low-energy component of the accelerated electron spectrum is well below the ponderomotive scaling and Beg's law. We have obtained relatively low conversion efficiency of laser energy into the energy of hot electrons propagating through the solid target of about 2%. It is demonstrated that the assumption about a single-temperature hot electron energy distribution with the slope temperature described by the ponderomotive scaling relationship, without detailed analysis of the hot electron spectrum, can lead to strong overestimation of the laser-to-electron energy-conversion efficiency, in particular, the conversion efficiency of laser energy into the high-temperature component of the hot electron distribution.

Module Eleven: Capacitance; Basic Electricity and Electronics Individualized Learning System.

ERIC Educational Resources Information Center

Bureau of Naval Personnel, Washington, DC.

In this module the student will learn about another circuit quantity, capacitance, and discover the effects of this component on circuit current, voltage, and power. The module is divided into seven lessons: the capacitor, theory of capacitance, total capacitance, RC (resistive-capacitive circuit) time constant, capacitive reactance, phase and…

How to protect a wind turbine from lightning

NASA Technical Reports Server (NTRS)

Dodd, C. W.; Mccalla, T., Jr.; Smith, J. G.

1983-01-01

Techniques for reducing the chances of lightning damage to wind turbines are discussed. The methods of providing a ground for a lightning strike are discussed. Then details are given on ways to protect electronic systems, generating and power equipment, blades, and mechanical components from direct and nearby lightning strikes.

The Articulation of Secondary and Post-Secondary Vocational Education Programs. Workshop Products.

ERIC Educational Resources Information Center

Keene State Coll., NH.

As a result of the cooperative efforts in articulation by secondary/postsecondary instructor teams, six packages representing the occupational areas of child care, culinary arts, electronics, health occupations, power mechanics, and industrial welding were developed. Each package contains the following three components: a series of job titles…

Application of automatic image analysis in wood science

Treesearch

Charles W. McMillin

1982-01-01

In this paper I describe an image analysis system and illustrate with examples the application of automatic quantitative measurement to wood science. Automatic image analysis, a powerful and relatively new technology, uses optical, video, electronic, and computer components to rapidly derive information from images with minimal operator interaction. Such instruments...

Compact, Low-Profile Power Converters: Highly-Laminated, High-Saturation-Flux-Density, Magnetic Cores for On-Chip Inductors in Power Converter Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2010-09-01

ADEPT Project: Georgia Tech is creating compact, low-profile power adapters and power bricks using materials and tools adapted from other industries and from grid-scale power applications. Adapters and bricks convert electrical energy into useable power for many types of electronic devices, including laptop computers and mobile phones. These converters are often called wall warts because they are big, bulky, and sometimes cover up an adjacent wall socket that could be used to power another electronic device. The magnetic components traditionally used to make adapters and bricks have reached their limits; they can't be made any smaller without sacrificing performance. Georgiamore » Tech is taking a cue from grid-scale power converters that use iron alloys as magnetic cores. These low-cost alloys can handle more power than other materials, but the iron must be stacked in insulated plates to maximize energy efficiency. In order to create compact, low-profile power adapters and bricks, these stacked iron plates must be extremely thin-only hundreds of nanometers in thickness, in fact. To make plates this thin, Georgia Tech is using manufacturing tools used in microelectromechanics and other small-scale industries.« less

Disruption avoidance by means of electron cyclotron waves

NASA Astrophysics Data System (ADS)

Esposito, B.; Granucci, G.; Maraschek, M.; Nowak, S.; Lazzaro, E.; Giannone, L.; Gude, A.; Igochine, V.; McDermott, R.; Poli, E.; Reich, M.; Sommer, F.; Stober, J.; Suttrop, W.; Treutterer, W.; Zohm, H.; ASDEX Upgrade, the; FTU Teams

2011-12-01

Disruptions are very challenging to ITER operation as they may cause damage to plasma facing components due to direct plasma heating, forces on structural components due to halo and eddy currents and the production of runaway electrons. Electron cyclotron (EC) waves have been demonstrated as a tool for disruption avoidance by a large set of recent experiments performed in ASDEX Upgrade and FTU using various disruption types, plasma operating scenarios and power deposition locations. The technique is based on the stabilization of magnetohydrodynamic (MHD) modes (mainly m/n = 2/1) through the localized injection of EC power on the resonant surface. This paper presents new results obtained in ASDEX Upgrade regarding stable operation above the Greenwald density achieved after avoidance of density limit disruptions by means of ECRH and suitable density feedback control (L-mode ohmic plasmas, Ip = 0.6 MA, Bt = 2.5 T) and NTM-driven disruptions at high-β limit delayed/avoided by means of both co-current drive (co-ECCD) and pure heating (ECRH) with power <=1.7 MW (H-mode NBI-heated plasmas, PNBI ~ 7.5 MW, Ip = 1 MA, Bt = 2.1 T, q95 ~ 3.6). The localized perpendicular injection of ECRH/ECCD onto a resonant surface leads to the delay and/or complete avoidance of disruptions. The experiments indicate the existence of a power threshold for mode stabilization to occur. An analysis of the MHD mode evolution using the generalized Rutherford equation coupled to the frequency and phase evolution equations shows that control of the modes is due to EC heating close to the resonant surface. The ECRH contribution (Δ'H term) is larger than the co-ECCD one in the initial and more important phase when the discharge is 'saved'. Future research and developments of the disruption avoidance technique are also discussed.

A Physically Transient Form of Silicon Electronics, With Integrated Sensors, Actuators and Power Supply

PubMed Central

Hwang, Suk-Won; Tao, Hu; Kim, Dae-Hyeong; Cheng, Huanyu; Song, Jun-Kyul; Rill, Elliott; Brenckle, Mark A.; Panilaitis, Bruce; Won, Sang Min; Kim, Yun-Soung; Yu, Ki Jun; Ameen, Abid; Li, Rui; Su, Yewang; Yang, Miaomiao; Kaplan, David L.; Zakin, Mitchell R.; Slepian, Marvin J.; Huang, Yonggang; Omenetto, Fiorenzo G.; Rogers, John A.

2013-01-01

A remarkable feature of modern silicon electronics is its ability to remain functionally and physically invariant, almost indefinitely for many practical purposes. Here, we introduce a silicon-based technology that offers the opposite behavior: it gradually vanishes over time, in a well-controlled, programmed manner. Devices that are ‘transient’ in this sense create application possibilities that cannot be addressed with conventional electronics, such as active implants that exist for medically useful timeframes, but then completely dissolve and disappear via resorption by the body. We report a comprehensive set of materials, manufacturing schemes, device components and theoretical design tools for a complementary metal oxide semiconductor (CMOS) electronics of this type, together with four different classes of sensors and actuators in addressable arrays, two options for power supply and a wireless control strategy. A transient silicon device capable of delivering thermal therapy in an implantable mode and its demonstration in animal models illustrate a system-level example of this technology. PMID:23019646

Local light-induced magnetization using nanodots and chiral molecules.

PubMed

Dor, Oren Ben; Morali, Noam; Yochelis, Shira; Baczewski, Lech Tomasz; Paltiel, Yossi

2014-11-12

With the increasing demand for miniaturization, nanostructures are likely to become the primary components of future integrated circuits. Different approaches are being pursued toward achieving efficient electronics, among which are spin electronics devices (spintronics). In principle, the application of spintronics should result in reducing the power consumption of electronic devices. Recently a new, promising, effective approach for spintronics has emerged, using spin selectivity in electron transport through chiral molecules. In this work, using chiral molecules and nanocrystals, we achieve local spin-based magnetization generated optically at ambient temperatures. Through the chiral layer, a spin torque can be transferred without permanent charge transfer from the nanocrystals to a thin ferromagnetic layer, creating local perpendicular magnetization. We used Hall sensor configuration and atomic force microscopy (AFM) to measure the induced local magnetization. At low temperatures, anomalous spin Hall effects were measured using a thin Ni layer. The results may lead to optically controlled spintronics logic devices that will enable low power consumption, high density, and cheap fabrication.

Microwave Driven Magnetic Plasma Accelerator Studies (CYCLOPS)

NASA Technical Reports Server (NTRS)

Crimi, G. F.; Eckert, A. C.; Miller, D. B.

1967-01-01

A microwave-driven cyclotron resonance plasma acceleration device was investigated using argon, krypton, xenon, and mercury as propellants. Limited ranges of propellant flow rate, input power, and magnetic field strength were used. Over-all efficiencies (including the 65% efficiency of the input polarizer) less than 10% were obtained for specific impulse values between 500 and 1500 sec. Power transfer efficiencies, however, approached 100% of the input power available in the right-hand component of the incident circularly polarized radiation. Beam diagnostics using Langmuir probes, cold gas mapping, r-f mapping and ion energy analyses were performed in conjunction with an engine operating in a pulsed mode. Measurements of transverse electron energies at the position of cyclotron resonant absorption yielded energy values more than an order of magnitude lower than anticipated. The measured electron energies were, however, consistent with the low values of average ion energy measured by retarding potential techniques. The low values of average ion energy were also consistent with the measured thrust values. It is hypothesized that ionization and radiation limit the electron kinetic energy to low-values thus limiting the energy which is finally transferred to the ion. Thermalization by electron-electron collision was also identified as an additional loss mechanism. The use of light alkali metals, which have relatively few low lying energy levels to excite, with the input power to mass ratio selected so as to limit the electron energies to less than the second ionization potential, is suggested. It is concluded, however, that the over-all efficiency for such propellants would be less than 40 per cent.

An explosively driven high-power microwave pulsed power system.

PubMed

Elsayed, M A; Neuber, A A; Dickens, J C; Walter, J W; Kristiansen, M; Altgilbers, L L

2012-02-01

The increased popularity of high power microwave systems and the various sources to drive them is the motivation behind the work to be presented. A stand-alone, self-contained explosively driven high power microwave pulsed power system has been designed, built, and tested at Texas Tech University's Center for Pulsed Power and Power Electronics. The system integrates four different sub-units that are composed of a battery driven prime power source utilizing capacitive energy storage, a dual stage helical flux compression generator as the main energy amplification device, an integrated power conditioning system with inductive energy storage including a fast opening electro-explosive switch, and a triode reflex geometry virtual cathode oscillator as the microwave radiating source. This system has displayed a measured electrical source power level of over 5 GW and peak radiated microwaves of about 200 MW. It is contained within a 15 cm diameter housing and measures 2 m in length, giving a housing volume of slightly less than 39 l. The system and its sub-components have been extensively studied, both as integrated and individual units, to further expand on components behavior and operation physics. This report will serve as a detailed design overview of each of the four subcomponents and provide detailed analysis of the overall system performance and benchmarks.

An explosively driven high-power microwave pulsed power system

NASA Astrophysics Data System (ADS)

Elsayed, M. A.; Neuber, A. A.; Dickens, J. C.; Walter, J. W.; Kristiansen, M.; Altgilbers, L. L.

2012-02-01

The increased popularity of high power microwave systems and the various sources to drive them is the motivation behind the work to be presented. A stand-alone, self-contained explosively driven high power microwave pulsed power system has been designed, built, and tested at Texas Tech University's Center for Pulsed Power and Power Electronics. The system integrates four different sub-units that are composed of a battery driven prime power source utilizing capacitive energy storage, a dual stage helical flux compression generator as the main energy amplification device, an integrated power conditioning system with inductive energy storage including a fast opening electro-explosive switch, and a triode reflex geometry virtual cathode oscillator as the microwave radiating source. This system has displayed a measured electrical source power level of over 5 GW and peak radiated microwaves of about 200 MW. It is contained within a 15 cm diameter housing and measures 2 m in length, giving a housing volume of slightly less than 39 l. The system and its sub-components have been extensively studied, both as integrated and individual units, to further expand on components behavior and operation physics. This report will serve as a detailed design overview of each of the four subcomponents and provide detailed analysis of the overall system performance and benchmarks.

Low-loss electron energy loss spectroscopy: An atomic-resolution complement to optical spectroscopies and application to graphene

DOE PAGES

Kapetanakis, Myron; Zhou, Wu; Oxley, Mark P.; ...

2015-09-25

Photon-based spectroscopies have played a central role in exploring the electronic properties of crystalline solids and thin films. They are a powerful tool for probing the electronic properties of nanostructures, but they are limited by lack of spatial resolution. On the other hand, electron-based spectroscopies, e.g., electron energy loss spectroscopy (EELS), are now capable of subangstrom spatial resolution. Core-loss EELS, a spatially resolved analog of x-ray absorption, has been used extensively in the study of inhomogeneous complex systems. In this paper, we demonstrate that low-loss EELS in an aberration-corrected scanning transmission electron microscope, which probes low-energy excitations, combined with amore » theoretical framework for simulating and analyzing the spectra, is a powerful tool to probe low-energy electron excitations with atomic-scale resolution. The theoretical component of the method combines density functional theory–based calculations of the excitations with dynamical scattering theory for the electron beam. We apply the method to monolayer graphene in order to demonstrate that atomic-scale contrast is inherent in low-loss EELS even in a perfectly periodic structure. The method is a complement to optical spectroscopy as it probes transitions entailing momentum transfer. The theoretical analysis identifies the spatial and orbital origins of excitations, holding the promise of ultimately becoming a powerful probe of the structure and electronic properties of individual point and extended defects in both crystals and inhomogeneous complex nanostructures. The method can be extended to probe magnetic and vibrational properties with atomic resolution.« less

"Double-Cable" Conjugated Polymers with Linear Backbone toward High Quantum Efficiencies in Single-Component Polymer Solar Cells.

PubMed

Feng, Guitao; Li, Junyu; Colberts, Fallon J M; Li, Mengmeng; Zhang, Jianqi; Yang, Fan; Jin, Yingzhi; Zhang, Fengling; Janssen, René A J; Li, Cheng; Li, Weiwei

2017-12-27

A series of "double-cable" conjugated polymers were developed for application in efficient single-component polymer solar cells, in which high quantum efficiencies could be achieved due to the optimized nanophase separation between donor and acceptor parts. The new double-cable polymers contain electron-donating poly(benzodithiophene) (BDT) as linear conjugated backbone for hole transport and pendant electron-deficient perylene bisimide (PBI) units for electron transport, connected via a dodecyl linker. Sulfur and fluorine substituents were introduced to tune the energy levels and crystallinity of the conjugated polymers. The double-cable polymers adopt a "face-on" orientation in which the conjugated BDT backbone and the pendant PBI units have a preferential π-π stacking direction perpendicular to the substrate, favorable for interchain charge transport normal to the plane. The linear conjugated backbone acts as a scaffold for the crystallization of the PBI groups, to provide a double-cable nanophase separation of donor and acceptor phases. The optimized nanophase separation enables efficient exciton dissociation as well as charge transport as evidenced from the high-up to 80%-internal quantum efficiency for photon-to-electron conversion. In single-component organic solar cells, the double-cable polymers provide power conversion efficiency up to 4.18%. This is one of the highest performances in single-component organic solar cells. The nanophase-separated design can likely be used to achieve high-performance single-component organic solar cells.

Development of the ITER ICH Transmission Line and Matching System

NASA Astrophysics Data System (ADS)

Rasmussen, D. A.; Goulding, R. H.; Pesavento, P. V.; Peters, B.; Swain, D. W.; Fredd, E. H.; Hosea, J.; Greenough, N.

2011-10-01

The ITER Ion Cyclotron Heating (ICH) System is designed to couple 20 MW of heating power for ion and electron heating. Prototype components for the ITER Ion Cyclotron Heating (ICH) transmission line and matching system are being designed and tested. The ICH transmission lines are pressurized 300 mm diameter coaxial lines with water-cooled aluminum outer conductor and gas-cooled and water-cooled copper inner conductor. Each ICH transmission line is designed to handle 40-55 MHz power at up to 6 MW/line. A total of 8 lines split to 16 antenna inputs on two ICH antennas. Industrial suppliers have designed coaxial transmission line and matching components and prototypes will be manufactured. The prototype components will be qualified on a test stand operating at the full power and pulse length needed for ITER. The matching system must accommodated dynamic changes in the plasma loading due to ELMS and the L to H-mode transition. Passive ELM tolerance will be performed using hybrid couplers and loads, which can absorb the transient reflected power. The system is also designed to compensate for the mutual inductances of the antenna current straps to limit the peak voltages on the antenna array elements.

Anode power deposition in a MPD thruster with a magnetically annulled Hall parameter anode

NASA Technical Reports Server (NTRS)

Gallimore, Alec D.; Kelly, Arnold J.; Jahn, Robert G.

1992-01-01

Results from previous studies indicate that the anode fall increases monotonically with the electron Hall parameter. In an attempt to reduce the anode fall by decreasing the local electron Hall parameter, a proof-of-concept test was performed in which an array of 36 permanent magnets were imbedded within the anode of a high power quasi-steady MPD thruster to decrease the local azimuthal component of the induced magnetic field. The modified thruster was operated at power levels between 150 kW and 4 MW with Ar and He propellants. Terminal voltage, triple probe, floating probe, and magnetic probe measurements were made to characterize the performance of the thruster with new anode. Incorporation of the modified anode resulted in a reduction of the anode fall by up to 15 V with Ar and 20 V with He, which corresponded to decreased anode power fractions of 40 and 45 percent with Ar and He, respectively.

Thermal Management and Reliability of Power Electronics and Electric Machines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Narumanchi, Sreekant

2016-09-19

Increasing the number of electric-drive vehicles (EDVs) on America's roads has been identified as a strategy with near-term potential for dramatically decreasing the nation's dependence on oil - by the U.S. Department of Energy, the federal cross-agency EV-Everywhere Challenge, and the automotive industry. Mass-market deployment will rely on meeting aggressive technical targets, including improved efficiency and reduced size, weight, and cost. Many of these advances will depend on optimization of thermal management. Effective thermal management is critical to improving the performance and ensuring the reliability of EDVs. Efficient heat removal makes higher power densities and lower operating temperatures possible, andmore » in turn enables cost and size reductions. The National Renewable Energy Laboratory (NREL), along with DOE and industry partners is working to develop cost-effective thermal management solutions to increase device and component power densities. In this presentation, the activities in recent years related to thermal management and reliability of automotive power electronics and electric machines are presented.« less

Investigation of multipactor breakdown in communication satellite microwave co-axial systems

NASA Astrophysics Data System (ADS)

Nagesh, S. K.; Revannasiddiah, D.; Shastry, S. V. K.

2005-01-01

Multipactor breakdown or multipactor discharge is a form of high frequency discharge that may occur in microwave components operating at very low pressures. Some RF components of multi-channel communication satellites have co-axial geometry and handle high RF power under near-vacuum conditions. The breakdown occurs due to secondary electron resonance, wherein electrons move back and forth in synchronism with the RF voltage across the gap between the inner and outer conductors of the co-axial structure. If the yield of secondary electrons from the walls of the co-axial structure is greater than unity, then the electron density increases with time and eventually leads to the breakdown. In this paper, the current due to the oscillating electrons in the co-axial geometry has been treated as a radially oriented Hertzian dipole. The electric field, due to this dipole, at any point in the coaxial structure, may then be determined by employing the dyadic Green's function technique. This field has been compared with the field that would exist in the absence of multipactor.

Effects of the non-extensive parameter on the propagation of ion acoustic waves in five-component cometary plasma system

NASA Astrophysics Data System (ADS)

Mahmoud, Abeer A.

2018-01-01

Some important evolution nonlinear partial differential equations are derived using the reductive perturbation method for unmagnetized collisionless system of five component plasma. This plasma system is a multi-ion contains negatively and positively charged Oxygen ions (heavy ions), positive Hydrogen ions (lighter ions), hot electrons from solar origin and colder electrons from cometary origin. The positive Hydrogen ion and the two types of electrons obey q-non-extensive distributions. The derived equations have three types of ion acoustic waves, which are soliton waves, shock waves and kink waves. The effects of the non-extensive parameters for the hot electrons, the colder electrons and the Hydrogen ions on the propagation of the envelope waves are studied. The compressive and rarefactive shapes of the three envelope waves appear in this system for the first order of the power of the nonlinearity strength with different values of non-extensive parameters. For the second order, the strength of nonlinearity will increase and the compressive type of the envelope wave only appears.

Fiber-based all-solid-state flexible supercapacitors for self-powered systems.

PubMed

Xiao, Xu; Li, Tianqi; Yang, Peihua; Gao, Yuan; Jin, Huanyu; Ni, Weijian; Zhan, Wenhui; Zhang, Xianghui; Cao, Yuanzhi; Zhong, Junwen; Gong, Li; Yen, Wen-Chun; Mai, Wenjie; Chen, Jian; Huo, Kaifu; Chueh, Yu-Lun; Wang, Zhong Lin; Zhou, Jun

2012-10-23

All-solid-state flexible supercapacitors based on a carbon/MnO(2) (C/M) core-shell fiber structure were fabricated with high electrochemical performance such as high rate capability with a scan rate up to 20 V s(-1), high volume capacitance of 2.5 F cm(-3), and an energy density of 2.2 × 10(-4) Wh cm(-3). By integrating with a triboelectric generator, supercapacitors could be charged and power commercial electronic devices, such as a liquid crystal display or a light-emitting-diode, demonstrating feasibility as an efficient storage component and self-powered micro/nanosystems.

Measurements of the Low Frequency Gain Fluctuations of a 30 GHz High-Electron-Mobility-Transistor Cryogenic Amplifier

NASA Technical Reports Server (NTRS)

Jarosik, Norman

1994-01-01

Low frequency gain fluctuations of a 30 GHz cryogenic HEMT amplifier have been measured with the input of the amplifier connected to a 15 K load. Effects of fluctuations of other components of the test set-up were eliminated by use of a power-power correlation technique. Strong correlation between output power fluctuations of the amplifier and drain current fluctuations of the transistors comprising the amplifier are observed. The existence of these correlations introduces the possibility of regressing some of the excess noise from the HEMT amplifier's output using the measured drain currents.

Integrated low power digital gyro control electronics

NASA Technical Reports Server (NTRS)

M'Closkey, Robert (Inventor); Grayver, Eugene (Inventor); Challoner, A. Dorian (Inventor); Hayworth, Ken J. (Inventor)

2005-01-01

Embodiments of the invention generally encompass a digital, application specific integrated circuit (ASIC) has been designed to perform excitation of a selected mode within a vibratory rate gyroscope, damping, or force-rebalance, of other modes within the sensor, and signal demodulation of the in-phase and quadrature components of the signal containing the angular rate information. The ASIC filters dedicated to each channel may be individually programmed to accommodate different rate sensor designs/technology or variations within the same class of sensors. The ASIC architecture employs a low-power design, making the ASIC, particularly suitable for use in power-sensitive applications.

Electrical design of Space Shuttle payload G-534: The pool boiling experiment

NASA Technical Reports Server (NTRS)

Francisco, David R.

1993-01-01

Payload G-534, the Pool Boiling Experiment (PBE), is a Get Away Special (GAS) payload that flew on the Space Shuttle Spacelab Mission J (STS 47) on September 19-21, 1992. This paper will give a brief overall description of the experiment with the main discussion being the electrical design with a detailed description of the power system and interface to the GAS electronics. The batteries used and their interface to the experiment Power Control Unit (PCU) and GAS electronics will be examined. The design philosophy for the PCU will be discussed in detail. The criteria for selection of fuses, relays, power semiconductors, and other electrical components along with grounding and shielding policy for the entire experiment are presented. The intent of this paper is to discuss the use of military tested parts and basic design guidelines to build a quality experiment for minimal additional cost.

Japanese power electronics inverter technology and its impact on the American air conditioning industry

NASA Astrophysics Data System (ADS)

Ushimaru, Kenji

1990-08-01

Since 1983, technological advances and market growth of inverter-driven variable-speed heat pumps in Japan have been dramatic. The high level of market penetration was promoted by a combination of political, economic, and trade policies in Japan. A unique environment was created in which the leading domestic industries, microprocessor manufacturing, compressors for air conditioning and refrigerators, and power electronic devices, were able to direct the development and market success of inverter-driven heat pumps. As a result, leading U.S. variable-speed heat pump manufacturers should expect a challenge from the Japanese producers of power devices and microprocessors. Because of the vertically-integrated production structure in Japan, in contrast to the out-sourcing culture of the United States, price competition at the component level (such as inverters, sensors, and controls) may impact the structure of the industry more severely than final product sales.

Effect of Electrostatic Discharge on Electrical Characteristics of Discrete Electronic Components

NASA Technical Reports Server (NTRS)

Wysocki, Phil; Vashchenko, Vladislav; Celaya, Jose; Saha, Sankalita; Goebel, Kai

2009-01-01

This article reports on preliminary results of a study conducted to examine how temporary electrical overstress seed fault conditions in discrete power electronic components that cannot be detected with reliability tests but impact longevity of the device. These defects do not result in formal parametric failures per datasheet specifications, but result in substantial change in the electrical characteristics when compared with pristine device parameters. Tests were carried out on commercially available 600V IGBT devices using transmission line pulse (TLP) and system level ESD stress. It was hypothesized that the ESD causes local damage during the ESD discharge which may greatly accelerate degradation mechanisms and thus reduce the life of the components. This hypothesis was explored in simulation studies where different types of damage were imposed to different parts of the device. Experimental results agree qualitatively with the simulation for a number of tests which will motivate more in-depth modeling of the damage.

An Electro-Optic Spatial Light Modulator for Thermoelastic Generation of Programmably Focused Ultrasound.

DTIC Science & Technology

1984-12-01

The concept proposed is an electro - optic technique that would make it possible to spatially modulate a high power pulsed laser beam to thermoelastically induce focused ultrasound in a test material. Being a purely electro - optic device, the modulator, and therefore the depth at which the acoustic focus occurs, can be programmed electronically at electronic speeds. If successful, it would become possible to scan ultrasound continuously in three dimensions within the component or structure under test. (Author)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bacon, L. D.

Hybrid Band{trademark} (H-band) is a Lockheed Martin Missiles and Fire Control (LMMFC) designation for a specific RF modulation that causes disruption of select electronic components and circuits. H-Band enables conventional high-power microwave (HPM) effects (with a center frequency of 1 to 2 GHz, for example) using a higher frequency carrier signal. The primary technical objective of this project was to understand the fundamental physics of Hybrid Band{trademark} Radio Frequency effects on electronic systems. The follow-on objective was to develop and validate a Hybrid Band{trademark} effects analysis process.

An electro-optic spatial light modulator for thermoelastic generation of programmably focused ultrasound

NASA Astrophysics Data System (ADS)

1984-12-01

The concept proposed is an electro-optic technique that would make it possible to spatially modulate a high power pulsed laser beam to thermoelastically induce focused ultrasound in a test material. Being a purely electro-optic device, the modulator, and therefore the depth at which the acoustic focus occurs, can be programmed electronically at electronic speeds. If successful, it would become possible to scan ultrasound continuously in three dimensions within the component or structure under test.

Optical analysis of high power free electron laser resonators

NASA Astrophysics Data System (ADS)

Knapp, C. E.; Viswanathan, V. K.; Appert, Q. D.; Bender, S. C.; McVey, B. D.

1987-06-01

The first part of this paper briefly describes the optics code used at Los Alamos National Laboratory to do optical analyses of various components of a free electron laser. The body of the paper then discusses the recent results in modeling low frequency gratings and ripple on the surfaces of liquid-cooled mirrors. The ripple is caused by structural/thermal effects in the mirror surface due to heating by optical absorption in high power resonators. Of interest is how much ripple can be permitted before diffractive losses or optical mode distortions become unacceptable. Preliminary work is presented involving classical diffraction problems to support the ripple study. The limitations of the techniques are discussed and the results are compared to experimental results where available.

Vibration energy harvesting with polyphase AC transducers

NASA Astrophysics Data System (ADS)

McCullagh, James J.; Scruggs, Jeffrey T.; Asai, Takehiko

2016-04-01

Three-phase transduction affords certain advantages in the efficient electromechanical conversion of energy, especially at higher power scales. This paper considers the use of a three-phase electric machine for harvesting energy from vibrations. We consider the use of vector control techniques, which are common in the area of industrial electronics, for optimizing the feedback loops in a stochastically-excited energy harvesting system. To do this, we decompose the problem into two separate feedback loops for direct and quadrature current components, and illustrate how each might be separately optimized to maximize power output. In a simple analytical example, we illustrate how these techniques might be used to gain insight into the tradeoffs in the design of the electronic hardware and the choice of bus voltage.

Deep Charging Evaluation of Satellite Power and Communication System Components

NASA Technical Reports Server (NTRS)

Schneider, T. A.; Vaughn, J. A.; Chu, B.; Wong, F.; Gardiner, G.; Wright, K. H.; Phillips, B.

2016-01-01

A set of deep charging tests has been carried out by NASA's Marshall Space Flight Center on subscale flight-like samples developed by Space Systems/Loral, LLC. The samples, which included solar array wire coupons, a photovoltaic cell coupon, and a coaxial microwave transmission cable, were placed in passive and active (powered) circuit configurations and exposed to electron radiation. The energy of the electron radiation was chosen to deeply penetrate insulating (dielectric) materials on each sample. Each circuit configuration was monitored to determine if potentially damaging electrostatic discharge events (arcs) were developed on the coupon as a result of deep charging. The motivation for the test, along with charging levels, experimental setup, sample details, and results will be discussed.

Filter for a drill string

DOEpatents

Hall, David R.; Pixton, David S.; Briscoe, Michael; McPherson, James

2007-12-04

A filter for a drill string comprises a perforated receptacle having an open end and a perforated end and first and second mounting surfaces are adjacent the open end. A transmission element is disposed within each of the first and second mounting surfaces. A capacitor may modify electrical characteristics of an LC circuit that comprises the transmission elements. The respective transmission elements are in communication with each other and with a transmission network integrated into the drill string. The transmission elements may be inductive couplers, direct electrical contacts, or optical couplers. In some embodiments of the present invention, the filter comprises an electronic component. The electronic component may be selected from the group consisting of a sensor, a router, a power source, a clock source, a repeater, and an amplifier.

Comparison of electron beam and laser beam powder bed fusion additive manufacturing process for high temperature turbine component materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dryepondt, Sebastien N; Pint, Bruce A; Ryan, Daniel

2016-04-01

The evolving 3D printer technology is now at the point where some turbine components could be additive manufactured (AM) for both development and production purposes. However, this will require a significant evaluation program to qualify the process and components to meet current design and quality standards. The goal of the project was to begin characterization of the microstructure and mechanical properties of Nickel Alloy X (Ni-22Cr-18Fe-9Mo) test bars fabricated by powder bed fusion (PBF) AM processes that use either an electron beam (EB) or laser beam (LB) power source. The AM materials produced with the EB and LB processes displayedmore » significant differences in microstructure and resultant mechanical properties. Accordingly, during the design analysis of AM turbine components, the specific mechanical behavior of the material produced with the selected AM process should be considered. Comparison of the mechanical properties of both the EB and LB materials to those of conventionally processed Nickel Alloy X materials indicates the subject AM materials are viable alternatives for manufacture of some turbine components.« less

High voltage breakdown phenomena in RF window, electron gun and RF cavities in 250 kW CW C band Klystron and their preventive measures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lamba, O.S.; Badola, Richa; Baloda, Suman

The paper describes voltage break down phenomenon and preventive measures in components of 250 KW CW, C band Klystron under development at CEERI Pilani. The Klystron operates at a beam voltage of 50 kV and delivers 250 kW RF power at 5 GHz frequency. The Klystron consists of several key components and regions, which are subject to high electrical stress. The most important regions of electrical breakdown are electron gun, the RF ceramic window and output cavity gap area. In the critical components voltage breakdown considered at design stage by proper gap and other techniques. All these problems discussed, asmore » well as solution to alleviate this problem. The electron gun consists basically of cathode, BFE and anode. The cathode is operated at a voltage of 50 kV. In order to maintain the voltage standoff between cathode and anode a high voltage alumina seal and RF window have been designed developed and successfully used in the tube. (author)« less

Investigation of soft component in cosmic ray detection

NASA Astrophysics Data System (ADS)

Oláh, László; Varga, Dezső

2017-07-01

Cosmic ray detection is a research area which finds various applications in tomographic imaging of large size objects. In such applications, the background sources which contaminate cosmic muon signal require a good understanding of the creation processes, as well as reliable simulation frameworks with high predictive power are needed. One of the main background source is the ;soft component;, that is electrons and positrons. In this paper a simulation framework based on GEANT4 has been established to pin down the key features of the soft component. We have found that the electron and positron flux shows a remarkable invariance against various model parameters including the muon emission altitude or primary particle energy distribution. The correlation between simultaneously arriving particles have been quantitatively investigated, demonstrating that electrons and positrons tend to arrive within a close distance and with low relative angle. This feature, which is highly relevant for counting detectors, has been experimentally verified under open sky and at shallow depth underground. The simulation results have been compared to existing other measurements as well as other simulation programs.

Behaviour of one-step spray-coated carbon nanotube supercapacitor in ambient light harvester circuit with printed organic solar cell and electrochromic display.

PubMed

Tuukkanen, Sampo; Välimäki, Marja; Lehtimäki, Suvi; Vuorinen, Tiina; Lupo, Donald

2016-03-09

A printed energy harvesting and storage circuit powered by ambient office lighting and its use to power a printed display is reported. The autonomous device is composed of three printed electronic components: an organic photovoltaic module, a carbon-nanotubes-only supercapacitor and an electrochromic display element. Components are fabricated from safe and environmentally friendly materials, and have been fabricated using solution processing methods, which translate into low-cost and high-throughput manufacturing. A supercapacitor made of spray-coated carbon nanotube based ink and aqueous NaCl electrolyte was charged using a printed organic photovoltaic module exposed to office lighting conditions. The supercapacitor charging rate, self-discharge rate and display operation were studied in detail. The supercapacitor self-discharge rate was found to depend on the charging rate. The fully charged supercapacitor was used as a power source to run the electrochromic display over 50 times.

Strong terahertz emission by optical rectification of shaped laser pulse in transversely magnetized plasma

NASA Astrophysics Data System (ADS)

Singh, Ram Kishor; Singh, Monika; Rajouria, Satish Kumar; Sharma, R. P.

2017-07-01

This communication presents a theoretical model for efficient terahertz (THz) radiation generation by the optical rectification of shaped laser pulse in transversely magnetised ripple density plasma. The laser beam imparts a nonlinear ponderomotive force to the electron and this force exerts a nonlinear velocity component in both transverse and axial directions which have spectral components in the THz range. These velocity components couple with the pre-existing density ripple and give rise to a strong nonlinear current density which drives the THz wave in the plasma. The THz yield increases with the increasing strength of the background magnetic field and the sensitivity depends on the ripple wave number. The emitted power is directly proportional to the square of the amplitude of the density ripple. For exact phase matching condition, the normalised power of the generated THz wave can be achieved of the order of 10-4.

Nanotechnology at NASA Ames

NASA Technical Reports Server (NTRS)

Srivastava, Deepak; Meyyappan, Meyya; Yan, Jerry (Technical Monitor)

2000-01-01

Advanced miniaturization, a key thrust area to enable new science and exploration missions, provides ultrasmall sensors, power sources, communication, navigation, and propulsion systems with very low mass, volume, and power consumption. Revolutions in electronics and computing will allow reconfigurable, autonomous, 'thinking' spacecraft. Nanotechnology presents a whole new spectrum of opportunities to build device components and systems for entirely new space architectures: (1) networks of ultrasmall probes on planetary surfaces; (2) micro-rovers that drive, hop, fly, and burrow; and (3) collections of microspacecraft making a variety of measurements.

Vector magnetometer design study: Analysis of a triaxial fluxgate sensor design demonstrates that all MAGSAT Vector Magnetometer specifications can be met

NASA Technical Reports Server (NTRS)

Adams, D. F.; Hartmann, U. G.; Lazarow, L. L.; Maloy, J. O.; Mohler, G. W.

1976-01-01

The design of the vector magnetometer selected for analysis is capable of exceeding the required accuracy of 5 gamma per vector field component. The principal elements that assure this performance level are very low power dissipation triaxial feedback coils surrounding ring core flux-gates and temperature control of the critical components of two-loop feedback electronics. An analysis of the calibration problem points to the need for improved test facilities.

Performance characterization of a permanent-magnet helicon plasma thruster

NASA Astrophysics Data System (ADS)

Takahashi, Kazunori; Charles, Christine; Boswell, Rod

2012-10-01

Helicon plasma thrusters operated at a few kWs of rf power is an active area of an international research. Recent experiments have clarified part of the thrust-generation mechanisms. Thrust components which have been identified include an electron pressure inside the source region and a Lorentz force due to an electron diamagnetic drift current and a radial component of the applied magnetic field. The use of permanent magnets (PMs) instead of solenoids is one of the solutions for improving the thruster efficiency because it does not require electricity for the magnetic nozzle formation. Here the thrust imparted from a permanent-magnet helicon plasma thruster is directly measured using a pendulum thrust balance. The source consists of permanent magnet (PM) arrays, a double turn rf loop antenna powered by a 13.56 MHz rf generator and a glass source tube. The PM arrays provide a magnetic nozzle near the open exit of the source and two configurations, which have maximum field strengths of about 100 and 270 G, are tested. A thrust of 15 mN, specific impulse of 2000 sec and a thrust efficiency of 8 percent are presently obtained for 2 kW of input power, 24 sccm flow rate of argon and the stronger magnetic field configuration.

3-D readout-electronics packaging for high-bandwidth massively paralleled imager

DOEpatents

Kwiatkowski, Kris; Lyke, James

2007-12-18

Dense, massively parallel signal processing electronics are co-packaged behind associated sensor pixels. Microchips containing a linear or bilinear arrangement of photo-sensors, together with associated complex electronics, are integrated into a simple 3-D structure (a "mirror cube"). An array of photo-sensitive cells are disposed on a stacked CMOS chip's surface at a 45.degree. angle from light reflecting mirror surfaces formed on a neighboring CMOS chip surface. Image processing electronics are held within the stacked CMOS chip layers. Electrical connections couple each of said stacked CMOS chip layers and a distribution grid, the connections for distributing power and signals to components associated with each stacked CSMO chip layer.

Electroactive polymer-based devices for e-textiles in biomedicine.

PubMed

Carpi, Federico; De Rossi, Danilo

2005-09-01

This paper describes the early conception and latest developments of electroactive polymer (EAP)-based sensors, actuators, electronic components, and power sources, implemented as wearable devices for smart electronic textiles (e-textiles). Such textiles, functioning as multifunctional wearable human interfaces, are today considered relevant promoters of progress and useful tools in several biomedical fields, such as biomonitoring, rehabilitation, and telemedicine. After a brief outline on ongoing research and the first products on e-textiles under commercial development, this paper presents the most highly performing EAP-based devices developed by our lab and other research groups for sensing, actuation, electronics, and energy generation/storage, with reference to their already demonstrated or potential applicability to electronic textiles.

Radio-frequency powered glow discharge device and method with high voltage interface

DOEpatents

Duckworth, D.C.; Marcus, R.K.; Donohue, D.L.; Lewis, T.A.

1994-06-28

A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components. 11 figures.

Radio-frequency powered glow discharge device and method with high voltage interface

DOEpatents

Duckworth, Douglas C.; Marcus, R. Kenneth; Donohue, David L.; Lewis, Trousdale A.

1994-01-01

A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components.

Extended performance electric propulsion power processor design study. Volume 2: Technical summary

NASA Technical Reports Server (NTRS)

Biess, J. J.; Inouye, L. Y.; Schoenfeld, A. D.

1977-01-01

Electric propulsion power processor technology has processed during the past decade to the point that it is considered ready for application. Several power processor design concepts were evaluated and compared. Emphasis was placed on a 30 cm ion thruster power processor with a beam power rating supply of 2.2KW to 10KW for the main propulsion power stage. Extension in power processor performance were defined and were designed in sufficient detail to determine efficiency, component weight, part count, reliability and thermal control. A detail design was performed on a microprocessor as the thyristor power processor controller. A reliability analysis was performed to evaluate the effect of the control electronics redesign. Preliminary electrical design, mechanical design and thermal analysis were performed on a 6KW power transformer for the beam supply. Bi-Mod mechanical, structural and thermal control configurations were evaluated for the power processor and preliminary estimates of mechanical weight were determined.

Wearable Electronics and Smart Textiles: A Critical Review

PubMed Central

Stoppa, Matteo; Chiolerio, Alessandro

2014-01-01

Electronic Textiles (e-textiles) are fabrics that feature electronics and interconnections woven into them, presenting physical flexibility and typical size that cannot be achieved with other existing electronic manufacturing techniques. Components and interconnections are intrinsic to the fabric and thus are less visible and not susceptible of becoming tangled or snagged by surrounding objects. E-textiles can also more easily adapt to fast changes in the computational and sensing requirements of any specific application, this one representing a useful feature for power management and context awareness. The vision behind wearable computing foresees future electronic systems to be an integral part of our everyday outfits. Such electronic devices have to meet special requirements concerning wearability. Wearable systems will be characterized by their ability to automatically recognize the activity and the behavioral status of their own user as well as of the situation around her/him, and to use this information to adjust the systems' configuration and functionality. This review focuses on recent advances in the field of Smart Textiles and pays particular attention to the materials and their manufacturing process. Each technique shows advantages and disadvantages and our aim is to highlight a possible trade-off between flexibility, ergonomics, low power consumption, integration and eventually autonomy. PMID:25004153

Wearable electronics and smart textiles: a critical review.

PubMed

Stoppa, Matteo; Chiolerio, Alessandro

2014-07-07

Electronic Textiles (e-textiles) are fabrics that feature electronics and interconnections woven into them, presenting physical flexibility and typical size that cannot be achieved with other existing electronic manufacturing techniques. Components and interconnections are intrinsic to the fabric and thus are less visible and not susceptible of becoming tangled or snagged by surrounding objects. E-textiles can also more easily adapt to fast changes in the computational and sensing requirements of any specific application, this one representing a useful feature for power management and context awareness. The vision behind wearable computing foresees future electronic systems to be an integral part of our everyday outfits. Such electronic devices have to meet special requirements concerning wearability. Wearable systems will be characterized by their ability to automatically recognize the activity and the behavioral status of their own user as well as of the situation around her/him, and to use this information to adjust the systems' configuration and functionality. This review focuses on recent advances in the field of Smart Textiles and pays particular attention to the materials and their manufacturing process. Each technique shows advantages and disadvantages and our aim is to highlight a possible trade-off between flexibility, ergonomics, low power consumption, integration and eventually autonomy.

Downhole tool

DOEpatents

Hall, David R.; Muradov, Andrei; Pixton, David S.; Dahlgren, Scott Steven; Briscoe, Michael A.

2007-03-20

A double shouldered downhole tool connection comprises box and pin connections having mating threads intermediate mating primary and secondary shoulders. The connection further comprises a secondary shoulder component retained in the box connection intermediate a floating component and the primary shoulders. The secondary shoulder component and the pin connection cooperate to transfer a portion of makeup load to the box connection. The downhole tool may be selected from the group consisting of drill pipe, drill collars, production pipe, and reamers. The floating component may be selected from the group consisting of electronics modules, generators, gyroscopes, power sources, and stators. The secondary shoulder component may comprises an interface to the box connection selected from the group consisting of radial grooves, axial grooves, tapered grooves, radial protrusions, axial protrusions, tapered protrusions, shoulders, and threads.

ORNL Lightweighting Research Featured on MotorWeek

ScienceCinema

None

2018-06-06

PBS MotorWeek, television's longest running automotive series, featured ORNL lightweighting research for vehicle applications in an episode that aired in early April 2014. The crew captured footage of research including development of new metal alloys, additive manufacturing, carbon fiber production, advanced batteries, power electronics components, and neutron imaging applications for materials evaluation.

78 FR 75360 - Notice of Issuance of Final Determination Concerning Certain Ethernet Switches

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-11

... printed circuit board assembly (``PCBA''), chassis, top cover, power supply, and fans. The switches... printed circuit board is populated with various electronic components to make a PCBA. 2. The PCBA is... Singapore. You argue that without the EOS software, the units exported from Singapore lack the intelligence...

KENNEDY SPACE CENTER, FLA. - During power-up of the orbiter Discovery in the Orbiter Processing Facility, a technician (left) looks at the circuit breaker lights in the cabin. Discovery has been undergoing Orbiter Major Modifications in the past year, ranging from wiring, control panels and black boxes to gaseous and fluid systems tubing and components. These systems were deserviced, disassembled, inspected, modified, reassembled, checked out and reserviced, as were most other systems onboard. The work includes the installation of the Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.”

NASA Image and Video Library

2003-08-27

KENNEDY SPACE CENTER, FLA. - During power-up of the orbiter Discovery in the Orbiter Processing Facility, a technician (left) looks at the circuit breaker lights in the cabin. Discovery has been undergoing Orbiter Major Modifications in the past year, ranging from wiring, control panels and black boxes to gaseous and fluid systems tubing and components. These systems were deserviced, disassembled, inspected, modified, reassembled, checked out and reserviced, as were most other systems onboard. The work includes the installation of the Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.”

Novel power MOSFET-based expander for high frequency ultrasound systems.

PubMed

Choi, Hojong; Shung, K Kirk

2014-01-01

The function of an expander is to obstruct the noise signal transmitted by the pulser so that it does not pass into the transducer or receive electronics, where it can produce undesirable ring-down in an ultrasound imaging application. The most common type is a diode-based expander, which is essentially a simple diode-pair, is widely used in pulse-echo measurements and imaging applications because of its simple architecture. However, diode-based expanders may degrade the performance of ultrasonic transducers and electronic components on the receiving and transmitting sides of the ultrasound systems, respectively. Since they are non-linear devices, they cause excessive signal attenuation and noise at higher frequencies and voltages. In this paper, a new type of expander that utilizes power MOSFET components, which we call a power MOSFET-based expander, is introduced and evaluated for use in high frequency ultrasound imaging systems. The performance of a power MOSFET-based expander was evaluated relative to a diode-based expander by comparing the noise figure (NF), insertion loss (IL), total harmonic distortion (THD), response time (RT), electrical impedance (EI) and dynamic power consumption (DPC). The results showed that the power MOSFET-based expander provided better NF (0.76 dB), IL (-0.3 dB) and THD (-62.9 dB), and faster RT (82 ns) than did the diode-based expander (NF (2.6 dB), IL (-1.4 dB), THD (-56.0 dB) and RT (119 ns)) at 70 MHz. The -6 dB bandwidth and the peak-to-peak voltage of the echo signal received by the transducer using the power MOSFET-based expander improved by 17.4% and 240% compared to the diode-based expander, respectively. The new power MOSFET-based expander was shown to yield lower NF, IL and THD, faster RT and lower ring down than the diode-based expander at the expense of higher dynamic power consumption. Copyright © 2013 Elsevier B.V. All rights reserved.

Novel Power MOSFET-Based Expander for High Frequency Ultrasound Systems

PubMed Central

Choi, Hojong; Shung, K. Kirk

2014-01-01

The function of an expander is to obstruct the noise signal transmitted by the pulser so that it does not pass into the transducer or receive electronics, where it can produce undesirable ring-down in an ultrasound imaging application. The most common type is a diode-based expander, which is essentially a simple diode-pair, is widely used in pulse-echo measurements and imaging applications because of its simple architecture. However, diode-based expanders may degrade the performance of ultrasonic transducers and electronic components on the receiving and transmitting sides of the ultrasound systems, respectively. Since they are non-linear devices, they cause excessive signal attenuation and noise at higher frequencies and voltages. In this paper, a new type of expander that utilizes power MOSFET components, which we call a power MOSFET-based expander, is introduced and evaluated for use in high frequency ultrasound imaging systems. The performance of a power MOSFET-based expander was evaluated relative to a diode-based expander by comparing the noise figure (NF), insertion loss (IL), total harmonic distortion (THD), response time (RT), electrical impedance (EI) and dynamic power consumption (DPC). The results showed that the power MOSFET-based expander provided better NF (0.76 dB), IL (-0.3 dB) and THD (-62.9 dB), and faster RT (82 ns) than did the diode-based expander (NF (2.6 dB), IL (-1.4 dB), THD (-56.0 dB) and RT (119 ns)) at 70 MHz. The -6 dB bandwidth and the peak-to-peak voltage of the echo signal received by the transducer using the power MOSFET-based expander improved by 17.4 % and 240 % compared to the diode-based expander, respectively. The new power MOSFET-based expander was shown to yield lower NF, IL and THD, faster RT and lower ring down than the diode-based expander at the expense of higher dynamic power consumption. PMID:23835308

Impute DC link (IDCL) cell based power converters and control thereof

DOEpatents

Divan, Deepakraj M.; Prasai, Anish; Hernendez, Jorge; Moghe, Rohit; Iyer, Amrit; Kandula, Rajendra Prasad

2016-04-26

Power flow controllers based on Imputed DC Link (IDCL) cells are provided. The IDCL cell is a self-contained power electronic building block (PEBB). The IDCL cell may be stacked in series and parallel to achieve power flow control at higher voltage and current levels. Each IDCL cell may comprise a gate drive, a voltage sharing module, and a thermal management component in order to facilitate easy integration of the cell into a variety of applications. By providing direct AC conversion, the IDCL cell based AC/AC converters reduce device count, eliminate the use of electrolytic capacitors that have life and reliability issues, and improve system efficiency compared with similarly rated back-to-back inverter system.

Power System for Venus Surface Exploration

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.; Mellott, Kenneth

2002-01-01

A radioisotope power and cooling system is designed to provide electrical power for a probe operating on the surface of Venus. Most foreseeable electronics devices and sensors cannot operate at the 450 C ambient surface temperature of Venus. Because the mission duration is substantially long and the use of thermal mass to maintain an operable temperature range is likely impractical, some type of active refrigeration may be required to keep electronic components at a temperature below ambient. The fundamental cooling parameters are the cold sink temperature, the hot sink temperature, and the amount of heat to be removed. In this instance, it is anticipated that electronics would have a nominal operating temperature of 300 C. Due to the highly thermal convective nature of the high-density (90 bar CO2) atmosphere, the hot sink temperature was assumed to be 50 C, which provided a 500 C temperature of the cooler's heat rejecter to the ambient atmosphere. The majority of the heat load on the cooler is from the high temperature ambient surface environment on Venus, with a small contribution of heat generation from electronics and sensors. Both thermoelectric (RTG) and dynamic power conversion systems were analyzed, based on use of a standard isotope (General-purpose heat source, or GPHS) brick. For the radioisotope Stirling power converter configuration designed, the Sage model predicts a thermodynamic power output capacity of 478.1 watts, which slightly exceeds the required 469.1 watts. The hot sink temperature is 1200 C, and the cold sink temperature is 500 C. The required heat input is 1740 watts. This gives a thermodynamic efficiency of 27.48 %. It is estimated that the mechanical efficiency of the power converter design is on the order of 85 %, based on experimental measurements taken from 500-watt power class, laboratory-tested Stirling engines. The overall efficiency is calculated to be 23.36 %. The mass of the power converter is estimated at approximately 21.6 kg. Additional information is included in the original extended abstract.

Bio-Nanobattery Development and Characterization

NASA Technical Reports Server (NTRS)

King, Glen C.; Choi, Sang H.; Chu, Sang-Hyon; Kim, Jae-Woo; Watt, Gerald D.; Lillehei, Peter T.; Park, Yeonjoon; Elliott, James R.

2005-01-01

A bio-nanobattery is an electrical energy storage device that utilizes organic materials and processes on an atomic, or nanometer-scale. The bio-nanobattery under development at NASA s Langley Research Center provides new capabilities for electrical power generation, storage, and distribution as compared to conventional power storage systems. Most currently available electronic systems and devices rely on a single, centralized power source to supply electrical power to a specified location in the circuit. As electronic devices and associated components continue to shrink in size towards the nanometer-scale, a single centralized power source becomes impractical. Small systems, such as these, will require distributed power elements to reduce Joule heating, to minimize wiring quantities, and to allow autonomous operation of the various functions performed by the circuit. Our research involves the development and characterization of a bio-nanobattery using ferritins reconstituted with both an iron core (Fe-ferritin) and a cobalt core (Co-ferritin). Synthesis and characterization of the Co-ferritin and Fe-ferritin electrodes were performed, including reducing capability and the half-cell electrical potentials. Electrical output of nearly 0.5 V for the battery cell was measured. Ferritin utilizing other metallic cores were also considered to increase the overall electrical output. Two dimensional ferritin arrays were produced on various substrates to demonstrate the feasibility of a thin-film nano-scaled power storage system for distributed power storage applications. The bio-nanobattery will be ideal for nanometerscaled electronic applications, due to the small size, high energy density, and flexible thin-film structure. A five-cell demonstration article was produced for concept verification and bio-nanobattery characterization. Challenges to be addressed include the development of a multi-layered thin-film, increasing the energy density, dry-cell bionanobattery development, and selection of ferritin core materials to allow the broadest range of applications. The potential applications for the distributed power system include autonomously-operating intelligent chips, flexible thin-film electronic circuits, nanoelectromechanical systems (NEMS), ultra-high density data storage devices, nanoelectromagnetics, quantum electronic devices, biochips, nanorobots for medical applications and mechanical nano-fabrication, etc.

FY2011 Oak Ridge National Laboratory Annual Progress Report for the Power Electronics and Electric Machinery Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszewski, Mitchell

The U.S. Department of Energy (DOE) announced in May 2011 a new cooperative research effort comprising DOE, the U.S. Council for Automotive Research (composed of automakers Ford Motor Company, General Motors Company, and Chrysler Group), Tesla Motors, and representatives of the electric utility and petroleum industries. Known as U.S. DRIVE (Driving Research and Innovation for Vehicle efficiency and Energy sustainability), it represents DOE's commitment to developing public-private partnerships to fund high risk-high reward research into advanced automotive technologies. The new partnership replaces and builds upon the partnership known as FreedomCAR (derived from 'Freedom' and 'Cooperative Automotive Research') that ran frommore » 2002 through 2010 and the Partnership for a New Generation of Vehicles initiative that ran from 1993 through 2001. The Oak Ridge National Laboratory's (ORNL's) Power Electronics and Electric Machines (PEEM) subprogram within the DOE Vehicle Technologies Program (VTP) provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on developing revolutionary new power electronics (PE), electric motor (EM), and traction drive system technologies that will leapfrog current on-the-road technologies. The research and development (R&D) is also aimed at achieving a greater understanding of and improvements in the way the various new components of tomorrow's automobiles will function as a unified system to improve fuel efficiency. In supporting the development of advanced vehicle propulsion systems, the PEEM subprogram has enabled the development of technologies that will significantly improve efficiency, costs, and fuel economy. The PEEM subprogram supports the efforts of the U.S. DRIVE partnership through a three phase approach intended to: (1) identify overall propulsion and vehicle related needs by analyzing programmatic goals and reviewing industry's recommendations and requirements and then develop the appropriate technical targets for systems, subsystems, and component R&D activities; (2) develop and validate individual subsystems and components, including EMs and PE; and (3) determine how well the components and subsystems work together in a vehicle environment or as a complete propulsion system and whether the efficiency and performance targets at the vehicle level have been achieved. The research performed under this subprogram will help remove technical and cost barriers to enable the development of technology for use in such advanced vehicles as hybrid electric vehicles (HEVs), plug-in HEVs (PHEVs), battery electric vehicles, and fuel-cell-powered automobiles that meet the goals of the VTP. A key element in making these advanced vehicles practical is providing an affordable electric traction drive system. This will require attaining weight, volume, efficiency, and cost targets for the PE and EM subsystems of the traction drive system. Areas of development include: (1) novel traction motor designs that result in increased power density and lower cost; (2) inverter technologies involving new topologies to achieve higher efficiency with the ability to accommodate higher temperature environments while achieving high reliability; (3) converter concepts that use methods of reducing the component count and integrating functionality to decrease size, weight, and cost; (4) new onboard battery charging concepts that result in decreased cost and size; (5) more effective thermal control through innovative packaging technologies; and (6) integrated motor-inverter traction drive system concepts. ORNL's PEEM research program conducts fundamental research, evaluates hardware, and assists in the technical direction of the VTP Advanced Power Electronics and Electric Motors (APEEM) program. In this role, ORNL serves on the U.S. DRIVE Electrical and Electronics Technical Team, evaluates proposals for DOE, and lends its technological expertise to the direction of projects and evaluation of developing technologies. ORNL also executes specific projects for DOE. DOE's continuing R&D into advanced vehicle technologies for transportation offers the possibility of reducing the nation's dependence on foreign oil and the negative economic impacts of crude oil price fluctuations. It also supports the Administration's goal of deploying 1 million PHEVs by 2015.« less

Reliability analysis of component-level redundant topologies for solid-state fault current limiter

NASA Astrophysics Data System (ADS)

Farhadi, Masoud; Abapour, Mehdi; Mohammadi-Ivatloo, Behnam

2018-04-01

Experience shows that semiconductor switches in power electronics systems are the most vulnerable components. One of the most common ways to solve this reliability challenge is component-level redundant design. There are four possible configurations for the redundant design in component level. This article presents a comparative reliability analysis between different component-level redundant designs for solid-state fault current limiter. The aim of the proposed analysis is to determine the more reliable component-level redundant configuration. The mean time to failure (MTTF) is used as the reliability parameter. Considering both fault types (open circuit and short circuit), the MTTFs of different configurations are calculated. It is demonstrated that more reliable configuration depends on the junction temperature of the semiconductor switches in the steady state. That junction temperature is a function of (i) ambient temperature, (ii) power loss of the semiconductor switch and (iii) thermal resistance of heat sink. Also, results' sensitivity to each parameter is investigated. The results show that in different conditions, various configurations have higher reliability. The experimental results are presented to clarify the theory and feasibility of the proposed approaches. At last, levelised costs of different configurations are analysed for a fair comparison.

Simulation and Characterization of a Miniaturized Scanning Electron Microscope

NASA Technical Reports Server (NTRS)

Gaskin, Jessica A.; Jerman, Gregory A.; Medley, Stephanie; Gregory, Don; Abbott, Terry O.; Sampson, Allen R.

2011-01-01

A miniaturized Scanning Electron Microscope (mSEM) for in-situ lunar investigations is being developed at NASA Marshall Space Flight Center with colleagues from the University of Alabama in Huntsville (UAH), Advanced Research Systems (ARS), the University of Tennessee in Knoxville (UTK) and Case Western Reserve University (CWRU). This effort focuses on the characterization of individual components of the mSEM and simulation of the complete system. SEMs can provide information on the size, shape, morphology and chemical composition of lunar regolith. Understanding these basic properties will allow us to better estimate the challenges associated with In-Situ Resource Utilization and to improve our basic science knowledge of the lunar surface (either precluding the need for sample return or allowing differentiation of unique samples to be returned to Earth.) The main components of the mSEM prototype includes: a cold field emission electron gun (CFEG), focusing lens, deflection/scanning system and backscatter electron detector. Of these, the electron gun development is of particular importance as it dictates much of the design of the remaining components. A CFEG was chosen for use with the lunar mSEM as its emission does not depend on heating of the tungsten emitter (lower power), it offers a long operation lifetime, is orders of magnitude brighter than tungsten hairpin guns, has a small source size and exhibits low beam energy spread.

Fabrication of compact electron gun for 6 MeV X-ray source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghodke, S.R.; Barnwal, Rajesh; Kumar, Mahendra, E-mail: ghodke_barc@yahoo.co.in

The 6 MeV X-Ray source for container cargo scanning application has been designed and developed by the Accelerator and Pulse Power Division, BARC, Mumbai. This compact linac has been designed as a mobile system, to be mounted on a moving container. In linac-based cargo-scanning system, to work electron gun on a movable container, it has to be robust. Electron gun is to work at 10{sup -7} mbar vacuum and 2000 degree Celsius temperature. An effort is made to engineer the gun assembly to make it more robust and aligned. The linac acts as the source of X-rays, which fall onmore » the cargo and are then detected by the detector system. Many components are indigenously developed like grid, insulating ring, Tungsten filament and filament guide, which are made from alumina ceramic and Tantalum which is to work at 1500 degree Celsius. Filament connector is made from Invar to reduce heat loss and to make rigid connection. It was CNC machined and wire cut by EDM. Invar and Copper electrode feed through is shrink fitted with the help of liquid Nitrogen. Shrink fit tolerances of 15 micrometer are achieved by jig boring machining processes. Tantalum cup for LaB6 cathode and heat shield are made from die and punch mechanism. For alignment of electron emitter with beam axis this Tantalum cup is a crucial component. Electron gun is assembled and aligned its components with the help of precision jigs. The whole assembly was Helium leak tested by MSLD up to 4 x 10{sup -10} mbar.l/s vacuum, no leak was found. This paper will describe the machining, Tantalum cup forming, ceramic components development, heat shields, ceramic feed through etc of electron gun. (author)« less

Kinetic Features Observed in the Solar Wind Electron Distributions

NASA Astrophysics Data System (ADS)

Pierrard, V.; Lazar, M.; Poedts, S.

2016-12-01

More than 120 000 of velocity distributions measured by Helios, Cluster and Ulysses in the ecliptic have been analyzed within an extended range of heliocentric distances from 0.3 to over 4 AU. The velocity distribution of electrons reveal a dual structure with a thermal (Maxwellian) core and a suprathermal (Kappa) halo. A detailed observational analysis of these two components provides estimations of their temperatures and temperature anisotropies, and we decode any potential interdependence that their properties may indicate. The core temperature is found to decrease with the radial distance, while the halo temperature slightly increases, clarifying an apparent contradiction in previous observational analysis and providing valuable clues about the temperature of the Kappa-distributed populations. For low values of the power-index kappa, these two components manifest a clear tendency to deviate from isotropy in the same direction, that seems to confirm the existence of mechanisms with similar effects on both components, e.g., the solar wind expansion, or the particle heating by the fluctuations. However, the existence of plasma states with anti-correlated anisotropies of the core and halo populations and the increase of their number for high values of the power-index kappa suggest a dynamic interplay of these components, mediated most probably by the anisotropy-driven instabilities. Estimating the temperature of the solar wind particles and their anisotropies is particularly important for understanding the origin of these deviations from thermal equilibrium as well as their effects.

Device for timing and power level setting for microwave applications

NASA Astrophysics Data System (ADS)

Ursu, M.-P.; Buidoş, T.

2016-08-01

Nowadays, the microwaves are widely used for various technological processes. The microwaves are emitted by magnetrons, which have strict requirements concerning power supplies for anode and filament cathodes, intensity of magnetic field, cooling and electromagnetic shielding. The magnetrons do not tolerate any alteration of their required voltages, currents and magnetic fields, which means that their output microwave power is fixed, so the only way to alter the power level is to use time-division, by turning the magnetron on and off by repetitive time patterns. In order to attain accurate and reproducible results, as well as correct and safe operation of the microwave device, all these requirements must be fulfilled. Safe, correct and reproducible operation of the microwave appliance can be achieved by means of a specially built electronic device, which ensures accurate and reproducible exposure times, interlocking of the commands and automatic switch off when abnormal operating conditions occur. This driving device, designed and realized during the completion of Mr.Ursu's doctoral thesis, consists of a quartz time-base, several programmable frequency and duration dividers, LED displays, sensors and interlocking gates. The active and passive electronic components are placed on custom-made PCB's, designed and made by means of computer-aided applications and machines. The driving commands of the electronic device are delivered to the magnetron power supplies by means of optic zero-passing relays. The inputs of the electronic driving device can sense the status of the microwave appliance. The user is able to enter the total exposure time, the division factor that sets the output power level and, as a novelty, the clock frequency of the time divider.

Irradiation caused performance losses of undulators equipped with Sm2Co17 magnets

NASA Astrophysics Data System (ADS)

Heidrich, S.; Aulenbacher, K.; Donders, S.; Nikipelov, A.

2018-06-01

The effects of beam losses on the performance of undulators equipped with Sm2Co17 magnets were investigated at the 855 MeV beamline of the Mainzer Microtron MAMI. Therefore, different cases containing undulator components as well as complete undulator assemblies were irradiated. Different types of shielding were used to distinguish the magnetic field degradation caused by neutrons from the degradation caused by electrons and photons. The results of each case were put in relation with the expected beam losses of a conceptional 10 kW free-electron-laser (FEL) based on an electron beam with 34 MW beam power.

Researcher Determining a Ruby Laser’s Effect on a Crystal

NASA Image and Video Library

1965-05-21

National Aeronautics and Space Administration (NASA) Lewis Research Center researcher Americo Forestieri aims a ruby laser beam at a crystal to determine the effects of its radiation. Forestieri was a researcher in the Electric Component Experiment Section of the Space Power System Division. Lewis was in the midst of a long-term effort to develop methods of delivering electrical power to spacecraft using nuclear, solar, or electrochemical technologies. Ruby lasers contain a ruby crystal with mirrors on either side. The laser action is created when a high-intensity lamp shines around the ruby and excites the electrons in the ruby’s chromium atoms. After the excitation, the electrons emit their ruby-red light. The mirrors reflect some of this red light back and forth inside the ruby which causes other excited chromium atoms to produce additional red light. This continues until the light pulse reaches high power levels and consumes all of the energy stored in the crystal. Forestieri used optical absorption and electron paramagnetic resonance techniques to study the extent and manner in which the radiation interacted with the samples. He determined that individual bands were assigned to specific electronic transitions. He also studied the atomic changes in the ruby crystals after irradiation. He found that complex interactions depend on the crystal pretreatment, purity, and irradiation dose.

Design of Servo Scheme and Drive Electronics for the Integrated Electrohydraulic Actuation System of RLV-TD

NASA Astrophysics Data System (ADS)

Kurian, Priya C.; Gopinath, Anish; Shinoy, K. S.; Santhi, P.; Sundaramoorthy, K.; Sebastian, Baby; Jaya, B.; Namboodiripad, M. N.; Mookiah, T.

2017-12-01

Reusable Launch Vehicle-Technology Demonstrator (RLV-TD) is a system which has the ability to carry a payload from the earth's surface to the outer space more than once. The control actuation forms the major component of the control system and it actuates the control surfaces of the RLV-TD based on the control commands. Eight electro hydraulic actuators were used in RLV-TD for vectoring the control surfaces about their axes. A centralised Hydraulic Power Generating Unit (HPU) was used for powering the eight actuators located in two stages. The actuation system had to work for the longest ever duration of about 850 s for an Indian launch vehicle. High bandwidth requirement from autopilot was met by the servo design using the nonlinear mathematical model. Single Control Electronics which drive four electrohydraulic actuators was developed for each stage. High power electronics with soft start scheme was realized for driving the BLDC motor which is the prime mover for hydraulic pump. Many challenges arose due to single HPU for two stages, uncertainty of aero load, higher bandwidth requirements etc. and provisions were incorporated in the design to successfully overcome them. This paper describes the servo design and control electronics architecture of control actuation system.

Modeling and control of hybrid wind/photovoltaic/fuel cell distributed generation systems

NASA Astrophysics Data System (ADS)

Wang, Caisheng

Due to ever increasing energy consumption, rising public awareness of environmental protection, and steady progress in power deregulation, alternative (i.e., renewable and fuel cell based) distributed generation (DG) systems have attracted increased interest. Wind and photovoltaic (PV) power generation are two of the most promising renewable energy technologies. Fuel cell (FC) systems also show great potential in DG applications of the future due to their fast technology development and many merits they have, such as high efficiency, zero or low emission (of pollutant gases) and flexible modular structure. The modeling and control of a hybrid wind/PV/FC DG system is addressed in this dissertation. Different energy sources in the system are integrated through an AC bus. Dynamic models for the main system components, namely, wind energy conversion system (WECS), PV energy conversion system (PVECS), fuel cell, electrolyzer, power electronic interfacing circuits, battery, hydrogen storage tank, gas compressor and gas pressure regulator, are developed. Two types of fuel cells have been modeled in this dissertation: proton exchange membrane fuel cell (PEMFC) and solid oxide fuel cell (SOFC). Power control of a grid-connected FC system as well as load mitigation control of a stand-alone FC system are investigated. The pitch angle control for WECS, the maximum power point tracking (MPPT) control for PVECS, and the control for electrolyzer and power electronic devices, are also addressed in the dissertation. Based on the dynamic component models, a simulation model for the proposed hybrid energy system has been developed using MATLAB/Simulink. The overall power management strategy for coordinating the power flows among the different energy sources is presented in the dissertation. Simulation studies have been carried out to verify the system performance under different scenarios using a practical load profile and real weather data. The results show that the overall power management strategy is effective and the power flows among the different energy sources and the load demand is balanced successfully. The DG's impacts on the existing power system are also investigated in this dissertation. Analytical methods for finding optimal sites to deploy DG sources in power systems are presented and verified with simulation studies.

Overview of the design of the ITER heating neutral beam injectors

NASA Astrophysics Data System (ADS)

Hemsworth, R. S.; Boilson, D.; Blatchford, P.; Dalla Palma, M.; Chitarin, G.; de Esch, H. P. L.; Geli, F.; Dremel, M.; Graceffa, J.; Marcuzzi, D.; Serianni, G.; Shah, D.; Singh, M.; Urbani, M.; Zaccaria, P.

2017-02-01

The heating neutral beam injectors (HNBs) of ITER are designed to deliver 16.7 MW of 1 MeV D0 or 0.87 MeV H0 to the ITER plasma for up to 3600 s. They will be the most powerful neutral beam (NB) injectors ever, delivering higher energy NBs to the plasma in a tokamak for longer than any previous systems have done. The design of the HNBs is based on the acceleration and neutralisation of negative ions as the efficiency of conversion of accelerated positive ions is so low at the required energy that a realistic design is not possible, whereas the neutralisation of H- and D- remains acceptable (≈56%). The design of a long pulse negative ion based injector is inherently more complicated than that of short pulse positive ion based injectors because: • negative ions are harder to create so that they can be extracted and accelerated from the ion source; • electrons can be co-extracted from the ion source along with the negative ions, and their acceleration must be minimised to maintain an acceptable overall accelerator efficiency; • negative ions are easily lost by collisions with the background gas in the accelerator; • electrons created in the extractor and accelerator can impinge on the extraction and acceleration grids, leading to high power loads on the grids; • positive ions are created in the accelerator by ionisation of the background gas by the accelerated negative ions and the positive ions are back-accelerated into the ion source creating a massive power load to the ion source; • electrons that are co-accelerated with the negative ions can exit the accelerator and deposit power on various downstream beamline components. The design of the ITER HNBs is further complicated because ITER is a nuclear installation which will generate very large fluxes of neutrons and gamma rays. Consequently all the injector components have to survive in that harsh environment. Additionally the beamline components and the NB cell, where the beams are housed, will be activated and all maintenance will have to be performed remotely. This paper describes the design of the HNB injectors, but not the associated power supplies, cooling system, cryogenic system etc, or the high voltage bushing which separates the vacuum of the beamline from the high pressure SF6 of the high voltage (1 MV) transmission line, through which the power, gas and cooling water are supplied to the beam source. Also the magnetic field reduction system is not described.

Electron cyclotron maser instability in the solar corona - The role of superthermal tails

NASA Technical Reports Server (NTRS)

Vlahos, L.; Sharma, R. R.

1985-01-01

The effect of a superthermal component of electrons on the loss-cone-driven electron cyclotron maser instability is analyzed. It is found that for a superthermal tail with temperature about 10 KeV, the first harmonic (X- and O-mode) is suppressed for n(t)/n(r) of about 1 (n/t/ and n/r/ are the densities of superthermal tail and loss-cone electrons) and the second harmonic (X- and O-modes) is suppressed for n(t)/n(r) less than about 0.1. A qualitative discussion on the formation of superthermal tails is presented and it is suggested that superthermal tails play an important role on the observed or available power, at microwave frequencies, from the electron cyclotron maser instability in the solar corona.

Liquid metal heat sink for high-power laser diodes

NASA Astrophysics Data System (ADS)

Vetrovec, John; Litt, Amardeep S.; Copeland, Drew A.; Junghans, Jeremy; Durkee, Roger

2013-02-01

We report on the development of a novel, ultra-low thermal resistance active heat sink (AHS) for thermal management of high-power laser diodes (HPLD) and other electronic and photonic components. AHS uses a liquid metal coolant flowing at high speed in a miniature closed and sealed loop. The liquid metal coolant receives waste heat from an HPLD at high flux and transfers it at much reduced flux to environment, primary coolant fluid, heat pipe, or structure. Liquid metal flow is maintained electromagnetically without any moving parts. Velocity of liquid metal flow can be controlled electronically, thus allowing for temperature control of HPLD wavelength. This feature also enables operation at a stable wavelength over a broad range of ambient conditions. Results from testing an HPLD cooled by AHS are presented.

Geant4 calculations for space radiation shielding material Al2O3

NASA Astrophysics Data System (ADS)

Capali, Veli; Acar Yesil, Tolga; Kaya, Gokhan; Kaplan, Abdullah; Yavuz, Mustafa; Tilki, Tahir

2015-07-01

Aluminium Oxide, Al2O3 is the most widely used material in the engineering applications. It is significant aluminium metal, because of its hardness and as a refractory material owing to its high melting point. This material has several engineering applications in diverse fields such as, ballistic armour systems, wear components, electrical and electronic substrates, automotive parts, components for electric industry and aero-engine. As well, it is used as a dosimeter for radiation protection and therapy applications for its optically stimulated luminescence properties. In this study, stopping powers and penetrating distances have been calculated for the alpha, proton, electron and gamma particles in space radiation shielding material Al2O3 for incident energies 1 keV - 1 GeV using GEANT4 calculation code.

The ac power line protection for an IEEE 587 Class B environment

NASA Technical Reports Server (NTRS)

Roehr, W. D.; Clark, O. M.

1984-01-01

The 587B series of protectors are unique, low clamping voltage transient suppressors to protect ac-powered equipment from the 6000V peak open-circuit voltage and 3000A short circuit current as defined in IEEE standard 587 for Category B transients. The devices, which incorporate multiple-stage solid-state protector components, were specifically designed to operate under multiple exposures to maximum threat levels in this severe environment. The output voltage peaks are limited to 350V under maximum threat conditions for a 120V ac power line, thus providing adequate protection to vulnerable electronic equipment. The principle of operation and test performance data is discussed.

Design of the ITER Electron Cyclotron Heating and Current Drive Waveguide Transmission Line

NASA Astrophysics Data System (ADS)

Bigelow, T. S.; Rasmussen, D. A.; Shapiro, M. A.; Sirigiri, J. R.; Temkin, R. J.; Grunloh, H.; Koliner, J.

2007-11-01

The ITER ECH transmission line system is designed to deliver the power, from twenty-four 1 MW 170 GHz gyrotrons and three 1 MW 127.5 GHz gyrotrons, to the equatorial and upper launchers. The performance requirements, initial design of components and layout between the gyrotrons and the launchers is underway. Similar 63.5 mm ID corrugated waveguide systems have been built and installed on several fusion experiments; however, none have operated at the high frequency and long-pulse required for ITER. Prototype components are being tested at low power to estimate ohmic and mode conversion losses. In order to develop and qualify the ITER components prior to procurement of the full set of 24 transmission lines, a 170 GHz high power test of a complete prototype transmission line is planned. Testing of the transmission line at 1-2 MW can be performed with a modest power (˜0.5 MW) tube with a low loss (10-20%) resonant ring configuration. A 140 GHz long pulse, 400 kW gyrotron will be used in the initial tests and a 170 GHz gyrotron will be used when it becomes available. Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Dept. of Energy under contract DE-AC05-00OR22725.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahedo, Eduardo; Merino, Mario

A previous axisymmetric model of the supersonic expansion of a collisionless, hot plasma in a divergent magnetic nozzle is extended here in order to include electron-inertia effects. Up to dominant order on all components of the electron velocity, electron momentum equations still reduce to three conservation laws. Electron inertia leads to outward electron separation from the magnetic streamtubes. The progressive plasma filling of the adjacent vacuum region is consistent with electron-inertia being part of finite electron Larmor radius effects, which increase downstream and eventually demagnetize the plasma. Current ambipolarity is not fulfilled and ion separation can be either outwards ormore » inwards of magnetic streamtubes, depending on their magnetization. Electron separation penalizes slightly the plume efficiency and is larger for plasma beams injected with large pressure gradients. An alternative nonzero electron-inertia model [E. Hooper, J. Propul. Power 9, 757 (1993)] based on cold plasmas and current ambipolarity, which predicts inwards electron separation, is discussed critically. A possible competition of the gyroviscous force with electron-inertia effects is commented briefly.« less

Simple photometer circuits using modular electronic components

NASA Technical Reports Server (NTRS)

Wampler, J. E.

1975-01-01

Operational and peak holding amplifiers are discussed as useful circuits for bioluminescence assays. Circuit diagrams are provided. While analog methods can give a good integration on short time scales, digital methods were found best for long term integration in bioluminescence assays. Power supplies, a general photometer circuit with ratio capability, and variations in the basic photometer design are also considered.

Observation of nanoscale magnetic fields using twisted electron beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grillo, Vincenzo; Harvey, Tyler R.; Venturi, Federico

Electron waves give an unprecedented enhancement to the field of microscopy by providing higher resolving power compared to their optical counterpart. Further information about a specimen, such as electric and magnetic features, can be revealed in electron microscopy because electrons possess both a magnetic moment and charge. In-plane magnetic structures in materials can be studied experimentally using the effect of the Lorentz force. On the other hand, full mapping of the magnetic field has hitherto remained challenging. Here we measure a nanoscale out-of-plane magnetic field by interfering a highly twisted electron vortex beam with a reference wave. We implement amore » recently developed holographic technique to manipulate the electron wavefunction, which gives free electrons an additional unbounded quantized magnetic moment along their propagation direction. Our finding demonstrates that full reconstruction of all three components of nanoscale magnetic fields is possible without tilting the specimen.« less

Observation of nanoscale magnetic fields using twisted electron beams

DOE PAGES

Grillo, Vincenzo; Harvey, Tyler R.; Venturi, Federico; ...

2017-09-25

Electron waves give an unprecedented enhancement to the field of microscopy by providing higher resolving power compared to their optical counterpart. Further information about a specimen, such as electric and magnetic features, can be revealed in electron microscopy because electrons possess both a magnetic moment and charge. In-plane magnetic structures in materials can be studied experimentally using the effect of the Lorentz force. On the other hand, full mapping of the magnetic field has hitherto remained challenging. Here we measure a nanoscale out-of-plane magnetic field by interfering a highly twisted electron vortex beam with a reference wave. We implement amore » recently developed holographic technique to manipulate the electron wavefunction, which gives free electrons an additional unbounded quantized magnetic moment along their propagation direction. Our finding demonstrates that full reconstruction of all three components of nanoscale magnetic fields is possible without tilting the specimen.« less

Phase space manipulation in high-brightness electron beams

NASA Astrophysics Data System (ADS)

Rihaoui, Marwan M.

Electron beams have a wide range of applications, including discovery science, medicine, and industry. Electron beams can also be used to power next-generation, high-gradient electron accelerators. The performances of some of these applications could be greatly enhanced by precisely tailoring the phase space distribution of the electron beam. The goal of this dissertation is to explore some of these phase space manipulations. We especially focus on transformations capable of tailoring the beam current distribution. Specifically, we investigate a beamline exchanging phase space coordinates between the horizontal and longitudinal degrees of freedom. The key components necessary for this beamline were constructed and tested. The preliminary beamline was used as a singleshot phase space diagnostics and to produce a train of picoseconds electron bunches. We also investigate the use of multiple electron beams to control the transverse focusing. Our numerical and analytical studies are supplemented with experiments performed at the Argonne Wakefield Accelerator.

Development of Power Electronics for a 0.2kW-Class Ion Thruster

NASA Technical Reports Server (NTRS)

Pinero, Luis R.; Patterson, Michael J.; Bowers, Glen E.

1997-01-01

Applications that might benefit from low power ion propulsion systems include Earth-orbit magnetospheric mapping satellite constellations, low Earth-orbit satellites, geosynchronous Earth-orbit satellite north-south stationkeeping, and asteroid orbiters. These spacecraft are likely to have masses on the order of 50 to 500 kg with up to 0.5 kW of electrical power available. A power processing unit for a 0.2 kW-class ion thruster is currently under development for these applications. The first step in this effort is the development and testing of a 0.24 kW beam power supply. The design incorporates a 20 kHz full bridge topology with multiple secondaries connected in series to obtain outputs of up to 1200 V(sub DC). A current-mode control pulse width modulation circuit built using discrete components was selected for this application. An input voltage of 28 +/- 4 V(sub DC) was assumed, since the small spacecraft for which this system is targeted are anticipated to have unregulated low voltage busses. Efficiencies in excess of 91 percent were obtained at maximum output power. The total mass of the breadboard was less than 1.0 kg and the component mass was 0.53 kg. It is anticipated that a complete flight power processor could weigh about 2.0 kg.

Portable data collection terminal in the automated power consumption measurement system

NASA Astrophysics Data System (ADS)

Vologdin, S. V.; Shushkov, I. D.; Bysygin, E. K.

2018-01-01

Aim of efficiency increasing, automation process of electric energy data collection and processing is very important at present time. High cost of classic electric energy billing systems prevent from its mass application. Udmurtenergo Branch of IDGC of Center and Volga Region developed electronic automated system called “Mobile Energy Billing” based on data collection terminals. System joins electronic components based on service-oriented architecture, WCF services. At present time all parts of Udmurtenergo Branch electric network are connected to “Mobile Energy Billing” project. System capabilities are expanded due to flexible architecture.

New electronics for the surface detectors of the Pierre Auger Observatory

NASA Astrophysics Data System (ADS)

Kleifges, M.; Pierre Auger Collaboration

2016-07-01

The Pierre Auger Observatory is the largest installation worldwide for the investigation of ultra-high energy cosmic rays. Air showers are detected using a hybrid technique with 27 fluorescence telescopes and 1660 water-Cherenkov detectors (WCD) distributed over about 3000 km2. The Auger Collaboration has decided to upgrade the electronics of the WCD and complement the surface detector with scintillators (SSD). The objective is to improve the separation between the muonic and the electron/photon shower component for better mass composition determination during an extended operation period of 8-10 years. The surface detector electronics records data locally and generates time stamps based on the GPS timing. The performance of the detectors is significantly improved with a higher sampling rate, an increased dynamic range, new generation of GPS receivers, and FPGA integrated CPU power. The number of analog channels will be increased to integrate the new SSD, but the power consumption needs to stay below 10 W to be able to use the existing photovoltaic system. In this paper, the concept of the additional SSD is presented with a focus on the design and performance of the new surface detector electronics.

Active noise control technique for diesel train locomotor exhaust noise abatement

NASA Astrophysics Data System (ADS)

Cotana, Franco; Rossi, Federico

2002-11-01

An original prototype for train locomotor exhaust gas pipe noise reduction (electronic muffler) is proposed: the system is based on an active noise control technique. An acoustical measurement campaign has shown that locomotor exhaust noise is characterized by very low frequency components (less than 80 Hz) and very high acoustic power (up to 110 dB). A peculiar electronic muffler characterized by high acoustical efficiency at very low frequencies has been designed and realized at Perugia University Acoustic Laboratory; it has been installed on an Italian D.245 train locomotor, equipped with a 500-kW diesel engine. The electronic muffler has been added to the traditional passive muffler. Very low transmission losses are introduced by the electronic muffler because of its particular shape; thus, engine efficiency does not further decrease. Canceling noise is generated by means of DSP-based numerical algorithm. Disturbing noise and canceling noise destructively interfere at the exhaust duct outlet section; outgoing noise is thus reduced. The control system reduces exhaust noise both in the steady and unsteady engine regime. Measurement results have shown that electronic muffler introduces up to 15 dB noise abatement in the low-frequency components.

Electromagnetic Electron Cyclotron Instability in the Solar Wind

NASA Astrophysics Data System (ADS)

Lazar, M.; Yoon, P. H.; López, R. A.; Moya, P. S.

2018-01-01

The abundant reports on the existence of electromagnetic high-frequency fluctuations in space plasmas have increased the expectations that theoretical modeling may help understand their origins and implications (e.g., kinetic instabilities and dissipation). This paper presents an extended quasi-linear approach of the electromagnetic electron cyclotron instability in conditions typical for the solar wind, where the anisotropic electrons (T⊥>T∥) exhibit a dual distribution combining a bi-Maxwellian core and bi-Kappa halo. Involving both the core and halo populations, the instability is triggered by the cumulative effects of these components, mainly depending of their anisotropies. The instability is not very sensitive to the shape of halo distribution function conditioned in this case by the power index κ. This result seems to be a direct consequence of the low density of electron halo, which is assumed more dilute than the core component in conformity with the observations in the ecliptic. Quasi-linear time evolutions predicted by the theory are confirmed by the particle-in-cell simulations, which also suggest possible explanations for the inherent differences determined by theoretical constraints. These results provide premises for an advanced methodology to characterize, realistically, the electromagnetic electron cyclotron instability and its implication in the solar wind.

Investigation of a large power water-cooled microwave resonance window for application with the ECR ion source

NASA Astrophysics Data System (ADS)

Guo, Guo; Guo, Junwei; Niu, Xinjian; Liu, Yinghui; Wang, Hui; Wei, Yanyu

2017-06-01

A large power water-cooled microwave resonance window used for the electron cyclotron resonance (ECR) ion source is investigated in this paper. The microwave characteristic simulation, thermal analysis, and structure design are deeply and successively carried out before fabrication. After the machining and welding of the components, the window is cold and hot tested. The application results demonstrate that when the input power is 2000 W, the reflected power is only 5 W. The vacuum is below 10-10 Pa, and the high power microwave operation can last 30 h continuously and reliably, which indicates that the design and assembling can achieve the high efficiency of the microwave transmission. Finally, the performance of the ECR ion source is enhanced by the improvement of the injected microwave power to the ECR plasma.

Adiabatic diesel engine component development: Reference engine for on-highway applications

NASA Technical Reports Server (NTRS)

Hakim, Nabil S.

1986-01-01

The main objectives were to select an advanced low heat rejection diesel reference engine (ADRE) and to carry out systems analysis and design. The ADRE concept selection consisted of: (1) rated point performance optimization; (2) study of various exhaust energy recovery scenarios; (3) components, systems and engine configuration studies; and (4) life cycle cost estimates of the ADRE economic worth. The resulting ADRE design proposed a reciprocator with many advanced features for the 1995 technology demonstration time frame. These included ceramic air gap insulated hot section structural components, high temperature tribology treatments, nonmechanical (camless) valve actuation systems, and elimination of the cylinder head gasket. ADRE system analysis and design resulted in more definition of the engine systems. These systems include: (1) electro-hydraulic valve actuation, (2) electronic common rail injection system; (3) engine electronic control; (4) power transfer for accessory drives and exhaust energy recovery systems; and (5) truck installation. Tribology and performance assessments were also carried out. Finite element and probability of survival analyses were undertaken for the ceramic low heat rejection component.

On the development of radiation tolerant surveillance camera from consumer-grade components

NASA Astrophysics Data System (ADS)

Klemen, Ambrožič; Luka, Snoj; Lars, Öhlin; Jan, Gunnarsson; Niklas, Barringer

2017-09-01

In this paper an overview on the process of designing a radiation tolerant surveillance camera from consumer grade components and commercially available particle shielding materials is given. This involves utilization of Monte-Carlo particle transport code MCNP6 and ENDF/B-VII.0 nuclear data libraries, as well as testing the physical electrical systems against γ radiation, utilizing JSI TRIGA mk. II fuel elements as a γ-ray sources. A new, aluminum, 20 cm × 20 cm × 30 cm irradiation facility with electrical power and signal wire guide-tube to the reactor platform, was designed and constructed and used for irradiation of large electronic and optical components assemblies with activated fuel elements. Electronic components to be used in the camera were tested against γ-radiation in an independent manner, to determine their radiation tolerance. Several camera designs were proposed and simulated using MCNP, to determine incident particle and dose attenuation factors. Data obtained from the measurements and MCNP simulations will be used to finalize the design of 3 surveillance camera models, with different radiation tolerances.

Advanced Materials for High Temperature, High Performance, Wide Bandgap Power Modules

NASA Astrophysics Data System (ADS)

O'Neal, Chad B.; McGee, Brad; McPherson, Brice; Stabach, Jennifer; Lollar, Richard; Liederbach, Ross; Passmore, Brandon

2016-01-01

Advanced packaging materials must be utilized to take full advantage of the benefits of the superior electrical and thermal properties of wide bandgap power devices in the development of next generation power electronics systems. In this manuscript, the use of advanced materials for key packaging processes and components in multi-chip power modules will be discussed. For example, to date, there has been significant development in silver sintering paste as a high temperature die attach material replacement for conventional solder-based attach due to the improved thermal and mechanical characteristics as well as lower processing temperatures. In order to evaluate the bond quality and performance of this material, shear strength, thermal characteristics, and void quality for a number of silver sintering paste materials were analyzed as a die attach alternative to solder. In addition, as high voltage wide bandgap devices shift from engineering samples to commercial components, passivation materials become key in preventing premature breakdown in power modules. High temperature, high dielectric strength potting materials were investigated to be used to encapsulate and passivate components internal to a power module. The breakdown voltage up to 30 kV and corresponding leakage current for these materials as a function of temperature is also presented. Lastly, high temperature plastic housing materials are important for not only discrete devices but also for power modules. As the operational temperature of the device and/or ambient temperature increases, the mechanical strength and dielectric properties are dramatically reduced. Therefore, the electrical characteristics such as breakdown voltage and leakage current as a function of temperature for housing materials are presented.

All-fiber pyroelectric nanogenerator

NASA Astrophysics Data System (ADS)

Ghosh, Sujoy Kumar; Xie, Mengying; Bowen, Christopher Rhys; Mandal, Dipankar

2018-04-01

An all-fiber pyroelectric nanogenerator (PyNG) is fabricated where both the active pyroelectric component and the electrodes were composed of fiber. The pyroelectric component was made with randomly organized electrospun PVDF nano-fibers possessing ferroelectric β- and γ-phases. The PyNG possess higher level of sensitivity which can detect very low level of temperature fluctuation, as, low as, 2 K. In addition, the thermal energy harvesting ability of the PyNG under several temperature variations and cycling frequencies paves the way for next generation thermal sensor and self-powered flexible micro-electronics.

Particle acceleration model for the broad-band baseline spectrum of the Crab nebula

NASA Astrophysics Data System (ADS)

Fraschetti, F.; Pohl, M.

2017-11-01

We develop a simple one-zone model of the steady-state Crab nebula spectrum encompassing both the radio/soft X-ray and the GeV/multi-TeV observations. By solving the transport equation for GeV-TeV electrons injected at the wind termination shock as a log-parabola momentum distribution and evolved via energy losses, we determine analytically the resulting differential energy spectrum of photons. We find an impressive agreement with the observed spectrum of synchrotron emission, and the synchrotron self-Compton component reproduces the previously unexplained broad 200-GeV peak that matches the Fermi/Large Area Telescope (LAT) data beyond 1 GeV with the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) data. We determine the parameters of the single log-parabola electron injection distribution, in contrast with multiple broken power-law electron spectra proposed in the literature. The resulting photon differential spectrum provides a natural interpretation of the deviation from power law customarily fitted with empirical multiple broken power laws. Our model can be applied to the radio-to-multi-TeV spectrum of a variety of astrophysical outflows, including pulsar wind nebulae and supernova remnants, as well as to interplanetary shocks.

Enhanced Electron Affinity and Exciton Confinement in Exciplex-Type Host: Power Efficient Solution-Processed Blue Phosphorescent OLEDs with Low Turn-on Voltage.

PubMed

Ban, Xinxin; Sun, Kaiyong; Sun, Yueming; Huang, Bin; Jiang, Wei

2016-01-27

A benzimidazole/phosphine oxide hybrid 1,3,5-tris(1-(4-(diphenylphosphoryl)phenyl)-1H-benzo[d]imidazol-2-yl)benzene (TPOB) was newly designed and synthesized as the electron-transporting component to form an exciplex-type host with the conventional hole-transporting material tris(4-carbazoyl-9-ylphenyl)amine (TCTA). Because of the enhanced triplet energy and electron affinity of TPOB, the energy leakage from exciplex-state to the constituting molecule was eliminated. Using energy transfer from exciplex-state, solution-processed blue phosphorescent organic light-emitting diodes (PHOLEDs) achieved an extremely low turn-on voltage of 2.8 V and impressively high power efficiency of 22 lm W(-1). In addition, the efficiency roll-off was very small even at luminance up to 10 000 cd m(-2), which suggested the balanced charge transfer in the emission layer. This study demonstrated that molecular modulation was an effective way to develop efficient exciplex-type host for high performanced PHOLEDs.

KM3NeT Digital Optical Module electronics

NASA Astrophysics Data System (ADS)

Real, Diego

2016-04-01

The KM3NeT collaboration is currently building of a neutrino telescope with a volume of several cubic kilometres at the bottom of the Mediterranean Sea. The telescope consists of a matrix of Digital Optical Modules that will detect the Cherenkov light originated by the interaction of the neutrinos in the proximity of the detector. This contribution describes the main components of the read-out electronics of the Digital Optical Module: the Power Board, which delivers all the power supply required by the Digital Optical Molule electronics; the Central Logic Board, the main core of the read-out system, hosting 31 Time to Digital Converters with 1 ns resolution and the White Rabbit protocol embedded in the Central Logic Board Field Programmable Gate Array; the Octopus boards, that transfer the Low Voltage Digital Signals from the PMT bases to the Central Logic Board and finally the PMT bases, in charge of converting the analogue signal produced in the 31 3" PMTs into a Low Voltage Digital Signal.

Analogy of transistor function with modulating photonic band gap in electromagnetically induced grating

PubMed Central

Wang, Zhiguo; Ullah, Zakir; Gao, Mengqin; Zhang, Dan; Zhang, Yiqi; Gao, Hong; Zhang, Yanpeng

2015-01-01

Optical transistor is a device used to amplify and switch optical signals. Many researchers focus on replacing current computer components with optical equivalents, resulting in an optical digital computer system processing binary data. Electronic transistor is the fundamental building block of modern electronic devices. To replace electronic components with optical ones, an equivalent optical transistor is required. Here we compare the behavior of an optical transistor with the reflection from a photonic band gap structure in an electromagnetically induced transparency medium. A control signal is used to modulate the photonic band gap structure. Power variation of the control signal is used to provide an analogy between the reflection behavior caused by modulating the photonic band gap structure and the shifting of Q-point (Operation point) as well as amplification function of optical transistor. By means of the control signal, the switching function of optical transistor has also been realized. Such experimental schemes could have potential applications in making optical diode and optical transistor used in quantum information processing. PMID:26349444

Analogy of transistor function with modulating photonic band gap in electromagnetically induced grating

NASA Astrophysics Data System (ADS)

Wang, Zhiguo; Ullah, Zakir; Gao, Mengqin; Zhang, Dan; Zhang, Yiqi; Gao, Hong; Zhang, Yanpeng

2015-09-01

Optical transistor is a device used to amplify and switch optical signals. Many researchers focus on replacing current computer components with optical equivalents, resulting in an optical digital computer system processing binary data. Electronic transistor is the fundamental building block of modern electronic devices. To replace electronic components with optical ones, an equivalent optical transistor is required. Here we compare the behavior of an optical transistor with the reflection from a photonic band gap structure in an electromagnetically induced transparency medium. A control signal is used to modulate the photonic band gap structure. Power variation of the control signal is used to provide an analogy between the reflection behavior caused by modulating the photonic band gap structure and the shifting of Q-point (Operation point) as well as amplification function of optical transistor. By means of the control signal, the switching function of optical transistor has also been realized. Such experimental schemes could have potential applications in making optical diode and optical transistor used in quantum information processing.

The merger of electrochemistry and molecular electronics.

PubMed

McCreery, Richard L

2012-02-01

Molecular Electronics has the potential to greatly enhance existing silicon-based microelectronics to realize new functions, higher device density, lower power consumption, and lower cost. Although the investigation of electron transport through single molecules and molecular monolayers in "molecular junctions" is a recent development, many of the relevant concepts and phenomena are derived from electrochemistry, as practiced for the past several decades. The past 10+ years have seen an explosion of research activity directed toward how the structure of molecules affects electron transport in molecular junctions, with the ultimate objective of "rational design" of molecular components with new electronic functions, such as chemical sensing, interactions with light, and low-cost, low-power consumer electronics. In order to achieve these scientifically and commercially important objectives, the factors controlling charge transport in molecules "connected" to conducting contacts must be understood, and methods for massively parallel manufacturing of molecular circuits must be developed. This Personal Account describes the development of reproducible and robust molecular electronic devices, starting with modified electrodes used in electrochemistry and progressing to manufacturable molecular junctions. Although the field faced some early difficulties in reliability and characterization, the pieces are now in place for rapid advances in understanding charge transport at the molecular level. Inherent in the field of Molecular Electronics are many electrochemical concepts, including tunneling, redox exchange, activated electron transfer, and electron coupling between molecules and conducting contacts. Copyright © 2012 The Japan Chemical Journal Forum and Wiley Periodicals, Inc.

Thermal management of high heat flux electronic components in space and aircraft systems, phase 1

NASA Astrophysics Data System (ADS)

Iversen, Arthur H.

1991-03-01

The objectives of this Phase 1 program were to analyze, design, construct and demonstrate the application of curved surface cooling to power devices with the goal of demonstrating greater than 200 W/sq cm chip dissipation while maintaining junction temperatures within specification. Major components of the experiment comprised the test fixture for mounting the device under test and the cooling loop equipment and instrumentation. The work conducted in this Phase 1 study was to establish the basic parameters for the design of an entire class of efficient, compact, lightweight and cost competitive power conversion/conditioning systems for space, aircraft and general DOD requirements. This has been accomplished. Chip power dissipation of greater than 400 W/sq cm was demonstrated, and a general packaging and the thermal management design has been devised to meet the above requirements. The power limit reached was dictated by the junction temperature and not power dissipation, i.e., critical heat flux. The key to the packaging design is a basic construction concept that provides low junction to fluid thermal resistance. High heat flux dissipation without low thermal resistance is useless because excessive junction temperatures will results.

Advanced combined iodine dispenser and detector. [for microorganism annihilation in potable water

NASA Technical Reports Server (NTRS)

Lantz, J. B.; Schubert, F. H.; Jensen, F. C.; Powell, J. D.

1977-01-01

A total weight of 1.23 kg (2.7 lb), a total volume of 1213 cu m (74 cu in), and an average power consumption of 5.5W was achieved in the advanced combined iodine dispenser/detector by integrating the detector with the iodine source, arranging all iodinator components within a compact package and lowering the parasitic power to the detector and electronics circuits. These achievements surpassed the design goals of 1.36 kg (3.0 lb), 1671 cu m (102 cu in) and 8W. The reliability and maintainability were improved by reducing the detector lamp power, using an interchangeable lamp concept, making the electronic circuit boards easily accessible, providing redundant water seals and improving the accessibility to the iodine accumulator for refilling. The system was designed to iodinate (to 5 ppm iodine) the fuel cell water generated during 27 seven-day orbiter missions (equivalent to 18,500 kg (40,700 lb) of water) before the unit must be recharged with iodine crystals.

Imaging the Impact of Proton Irradiation on Edge Terminations in Vertical GaN pin Diodes

DOE PAGES

Collins, Kimberlee C.; King, Michael P.; Dickerson, Jeramy R.; ...

2017-05-29

Devices based on GaN have shown great promise for high power electronics, including their potential use as radiation tolerant components. An important step to realizing high power diodes is the design and implementation of an edge termination to mitigate field crowding, which can lead to premature breakdown. However, little is known about the effects of radiation on edge termination functionality. We experimentally examine the effects of proton irradiation on multiple field ring edge terminations in high power vertical GaN pin diodes using in operando imaging with electron beam induced current (EBIC). We find that exposure to proton irradiation influences fieldmore » spreading in the edge termination as well as carrier transport near the anode. By using depth-dependent EBIC measurements of hole diffusion length in homoepitaxial n-GaN we demonstrate that the carrier transport effect is due to a reduction in hole diffusion length following proton irradiation.« less

Imaging the Impact of Proton Irradiation on Edge Terminations in Vertical GaN pin Diodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Collins, Kimberlee C.; King, Michael P.; Dickerson, Jeramy R.

Devices based on GaN have shown great promise for high power electronics, including their potential use as radiation tolerant components. An important step to realizing high power diodes is the design and implementation of an edge termination to mitigate field crowding, which can lead to premature breakdown. However, little is known about the effects of radiation on edge termination functionality. We experimentally examine the effects of proton irradiation on multiple field ring edge terminations in high power vertical GaN pin diodes using in operando imaging with electron beam induced current (EBIC). We find that exposure to proton irradiation influences fieldmore » spreading in the edge termination as well as carrier transport near the anode. By using depth-dependent EBIC measurements of hole diffusion length in homoepitaxial n-GaN we demonstrate that the carrier transport effect is due to a reduction in hole diffusion length following proton irradiation.« less

Maintaining Stability During a Conducted-Ripple EMC Test

NASA Technical Reports Server (NTRS)

Vorperian, Vatche

2007-01-01

An improved technique, and electronic circuitry to implement the technique, have been developed for a military-standard electromagnetic-compatibility (EMC) test in which one analyzes susceptibility to low-frequency ripple conducted into the equipment under test via a DC power line. In the traditional technique for performing the particular test, the ripple is coupled onto the DC power line via a transformer. Depending upon some design details of the equipment under test, the inductance of the transformer can contribute a degree of instability that results in an oscillation of amplitude large enough to destroy the equipment. It is usually possible to suppress the oscillation by connecting a damping resistor to the primary terminals of the ripple-injection transformer. However, it is important to emphasize the usually in the preceding sentence: sometimes, the resistive damping becomes insufficient to suppress destructive oscillation. In addition, undesirably, the resistor contributes to power dissipation and power demand, and thereby also necessitates the use of a larger ripple voltage amplifier. Yet another disadvantage of the transformer-coupling technique is that the transformer introduces low-frequency distortion of the injected ripple voltage. The improved technique makes it possible to inject ripple with very low distortion at low frequency, without inducing oscillation. In this technique, a transformer is not used: Instead, power is fed to the equipment under test via series power field-effect transistors (FETs) controlled by a summing operational amplifier. One of the inputs to the amplifier controls the DC component of the power-line voltage; the other input, generated by an external oscillator, controls the ripple component. The circuitry for implementing this technique includes panel displays, an internal power supply for the operational amplifier and panel displays, and amplitude controls for the DC and ripple powerline voltage components.

Assessment of Technologies for Noncryogenic Hybrid Electric Propulsion

NASA Technical Reports Server (NTRS)

Dever, Timothy P.; Duffy, Kirsten P.; Provenza, Andrew J.; Loyselle, Patricia L.; Choi, Benjamin B.; Morrison, Carlos R.; Lowe, Angela M.

2015-01-01

The Subsonic Fixed Wing Project of NASA's Fundamental Aeronautics Program is researching aircraft propulsion technologies that will lower noise, emissions, and fuel burn. One promising technology is noncryogenic electric propulsion, which could be either hybrid electric propulsion or turboelectric propulsion. Reducing dependence on the turbine engine would certainly reduce emissions. However, the weight of the electricmotor- related components that would have to be added would adversely impact the benefits of the smaller turbine engine. Therefore, research needs to be done to improve component efficiencies and reduce component weights. This study projects technology improvements expected in the next 15 and 30 years, including motor-related technologies, power electronics, and energy-storage-related technologies. Motor efficiency and power density could be increased through the use of better conductors, insulators, magnets, bearings, structural materials, and thermal management. Energy storage could be accomplished through batteries, flywheels, or supercapacitors, all of which expect significant energy density growth over the next few decades. A first-order approximation of the cumulative effect of each technology improvement shows that motor power density could be improved from 3 hp/lb, the state of the art, to 8 hp/lb in 15 years and 16 hp/lb in 30 years.

Comparing Server Energy Use and Efficiency Using Small Sample Sizes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coles, Henry C.; Qin, Yong; Price, Phillip N.

This report documents a demonstration that compared the energy consumption and efficiency of a limited sample size of server-type IT equipment from different manufacturers by measuring power at the server power supply power cords. The results are specific to the equipment and methods used. However, it is hoped that those responsible for IT equipment selection can used the methods described to choose models that optimize energy use efficiency. The demonstration was conducted in a data center at Lawrence Berkeley National Laboratory in Berkeley, California. It was performed with five servers of similar mechanical and electronic specifications; three from Intel andmore » one each from Dell and Supermicro. Server IT equipment is constructed using commodity components, server manufacturer-designed assemblies, and control systems. Server compute efficiency is constrained by the commodity component specifications and integration requirements. The design freedom, outside of the commodity component constraints, provides room for the manufacturer to offer a product with competitive efficiency that meets market needs at a compelling price. A goal of the demonstration was to compare and quantify the server efficiency for three different brands. The efficiency is defined as the average compute rate (computations per unit of time) divided by the average energy consumption rate. The research team used an industry standard benchmark software package to provide a repeatable software load to obtain the compute rate and provide a variety of power consumption levels. Energy use when the servers were in an idle state (not providing computing work) were also measured. At high server compute loads, all brands, using the same key components (processors and memory), had similar results; therefore, from these results, it could not be concluded that one brand is more efficient than the other brands. The test results show that the power consumption variability caused by the key components as a group is similar to all other components as a group. However, some differences were observed. The Supermicro server used 27 percent more power at idle compared to the other brands. The Intel server had a power supply control feature called cold redundancy, and the data suggest that cold redundancy can provide energy savings at low power levels. Test and evaluation methods that might be used by others having limited resources for IT equipment evaluation are explained in the report.« less

Polymer-free carbon nanotube thermoelectrics with improved charge carrier transport and power factor

DOE PAGES

Norton-Baker, Brenna; Ihly, Rachelle; Gould, Isaac E.; ...

2016-11-17

Here, semiconducting single-walled carbon nanotubes (s-SWCNTs) have recently attracted attention for their promise as active components in a variety of optical and electronic applications, including thermoelectricity generation. Here we demonstrate that removing the wrapping polymer from the highly enriched s-SWCNT network leads to substantial improvements in charge carrier transport and thermoelectric power factor. These improvements arise primarily from an increase in charge carrier mobility within the s-SWCNT networks because of removal of the insulating polymer and control of the level of nanotube bundling in the network, which enables higher thin-film conductivity for a given carrier density. Ultimately, these studies demonstratemore » that highly enriched s-SWCNT thin films, in the complete absence of any accompanying semiconducting polymer, can attain thermoelectric power factors in the range of approximately 400 μW m -1K -2, which is on par with that of some of the best single-component organic thermoelectrics demonstrated to date.« less

Component technology for space power systems

NASA Technical Reports Server (NTRS)

Finke, R. C.

1982-01-01

Progress made by NASA toward implementation of equipment for the conversion, management, and distribution of voltage power in space applications are reviewed. Work has been carried forward on components such as bipolar transistors, deep impurity semiconductors, conductors, dielectrics, magnetic devices, and rotary power transfer. Specific programs for the high voltage systems have included research on lightweight, low-cost conductors featuring graphite fibers containing electron donor materials for wires and cables with reduced mass and the conductivity of copper. Attention has also been given p-n junction technology for high-speed, high-current, high-voltage materials and diamond-like dielectric films which are hard, have high dielectric strength, and can operate up to 300 C. A transistor has been fabricated with a voltage of 1200 V at 100 A, with a gain of 10 and a 0.5 microsec rise/fall time. A 25 kW transformer has also been built which performs at 20 kHz with an efficiency of 99.2%.

Behaviour of one-step spray-coated carbon nanotube supercapacitor in ambient light harvester circuit with printed organic solar cell and electrochromic display

PubMed Central

Tuukkanen, Sampo; Välimäki, Marja; Lehtimäki, Suvi; Vuorinen, Tiina; Lupo, Donald

2016-01-01

A printed energy harvesting and storage circuit powered by ambient office lighting and its use to power a printed display is reported. The autonomous device is composed of three printed electronic components: an organic photovoltaic module, a carbon-nanotubes-only supercapacitor and an electrochromic display element. Components are fabricated from safe and environmentally friendly materials, and have been fabricated using solution processing methods, which translate into low-cost and high-throughput manufacturing. A supercapacitor made of spray-coated carbon nanotube based ink and aqueous NaCl electrolyte was charged using a printed organic photovoltaic module exposed to office lighting conditions. The supercapacitor charging rate, self-discharge rate and display operation were studied in detail. The supercapacitor self-discharge rate was found to depend on the charging rate. The fully charged supercapacitor was used as a power source to run the electrochromic display over 50 times. PMID:26957019

Simulation of cooling efficiency via miniaturised channels in multilayer LTCC for power electronics

NASA Astrophysics Data System (ADS)

Pietrikova, Alena; Girasek, Tomas; Lukacs, Peter; Welker, Tilo; Müller, Jens

2017-03-01

The aim of this paper is detailed investigation of thermal resistance, flow analysis and distribution of coolant as well as thermal distribution inside multilayer LTCC substrates with embedded channels for power electronic devices by simulation software. For this reason four various structures of internal channels in the multilayer LTCC substrates were designed and simulated. The impact of the volume flow, structures of channels, and power loss of chip was simulated, calculated and analyzed by using the simulation software Mentor Graphics FloEFDTM. The structure, size and location of channels have the significant impact on thermal resistance, pressure of coolant as well as the effectivity of cooling power components (chips) that can be placed on the top of LTCC substrate. The main contribution of this paper is thermal analyze, optimization and impact of 4 various cooling channels embedded in LTCC multilayer structure. Paper investigate, the effect of volume flow in cooling channels for achieving the least thermal resistance of LTCC substrate that is loaded by power thermal chips. Paper shows on the impact of the first chips thermal load on the second chip as well as. This possible new technology could ensure in the case of practical realization effective cooling and increasing reliability of high power modules.

Plasmon excitation in metal slab by fast point charge: The role of additional boundary conditions in quantum hydrodynamic model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Ying-Ying; Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario N2L 3G1; An, Sheng-Bai

2014-10-15

We study the wake effect in the induced potential and the stopping power due to plasmon excitation in a metal slab by a point charge moving inside the slab. Nonlocal effects in the response of the electron gas in the metal are described by a quantum hydrodynamic model, where the equation of electronic motion contains both a quantum pressure term and a gradient correction from the Bohm quantum potential, resulting in a fourth-order differential equation for the perturbed electron density. Thus, besides using the condition that the normal component of the electron velocity should vanish at the impenetrable boundary ofmore » the metal, a consistent inclusion of the gradient correction is shown to introduce two possibilities for an additional boundary condition for the perturbed electron density. We show that using two different sets of boundary conditions only gives rise to differences in the wake potential at large distances behind the charged particle. On the other hand, the gradient correction in the quantum hydrodynamic model is seen to cause a reduction in the depth of the potential well closest to the particle, and a reduction of its stopping power. Even for a particle moving in the center of the slab, we observe nonlocal effects in the induced potential and the stopping power due to reduction of the slab thickness, which arise from the gradient correction in the quantum hydrodynamic model.« less

Optically controlled laser-plasma electron accelerator for compact gamma-ray sources

NASA Astrophysics Data System (ADS)

Kalmykov, S. Y.; Davoine, X.; Ghebregziabher, I.; Shadwick, B. A.

2018-02-01

Generating quasi-monochromatic, femtosecond γ-ray pulses via Thomson scattering (TS) demands exceptional electron beam (e-beam) quality, such as percent-scale energy spread and five-dimensional brightness over 1016 A m-2. We show that near-GeV e-beams with these metrics can be accelerated in a cavity of electron density, driven with an incoherent stack of Joule-scale laser pulses through a mm-size, dense plasma (n 0 ˜ 1019 cm-3). Changing the time delay, frequency difference, and energy ratio of the stack components controls the e-beam phase space on the femtosecond scale, while the modest energy of the optical driver helps afford kHz-scale repetition rate at manageable average power. Blue-shifting one stack component by a considerable fraction of the carrier frequency makes the stack immune to self-compression. This, in turn, minimizes uncontrolled variation in the cavity shape, suppressing continuous injection of ambient plasma electrons, preserving a single, ultra-bright electron bunch. In addition, weak focusing of the trailing component of the stack induces periodic injection, generating, in a single shot, a train of bunches with controllable energy spacing and femtosecond synchronization. These designer e-beams, inaccessible to conventional acceleration methods, generate, via TS, gigawatt γ-ray pulses (or multi-color pulse trains) with the mean energy in the range of interest for nuclear photonics (4-16 MeV), containing over 106 photons within a microsteradian-scale observation cone.

Digitally controlled high-performance dc SQUID readout electronics for a 304-channel vector magnetometer

NASA Astrophysics Data System (ADS)

Bechstein, S.; Petsche, F.; Scheiner, M.; Drung, D.; Thiel, F.; Schnabel, A.; Schurig, Th

2006-06-01

Recently, we have developed a family of dc superconducting quantum interference device (SQUID) readout electronics for several applications. These electronics comprise a low-noise preamplifier followed by an integrator, and an analog SQUID bias circuit. A highly-compact low-power version with a flux-locked loop bandwidth of 0.3 MHz and a white noise level of 1 nV/√Hz was specially designed for a 304-channel low-Tc dc SQUID vector magnetometer, intended to operate in the new Berlin Magnetically Shielded Room (BMSR-2). In order to minimize the space needed to mount the electronics on top of the dewar and to minimize the power consumption, we have integrated four electronics channels on one 3 cm × 10 cm sized board. Furthermore we embedded the analog components of these four channels into a digitally controlled system including an in-system programmable microcontroller. Four of these integrated boards were combined to one module with a size of 4 cm × 4 cm × 16 cm. 19 of these modules were implemented, resulting in a total power consumption of about 61 W. To initialize the 304 channels and to service the system we have developed software tools running on a laptop computer. By means of these software tools the microcontrollers are fed with all required data such as the working points, the characteristic parameters of the sensors (noise, voltage swing), or the sensor position inside of the vector magnetometer system. In this paper, the developed electronics including the software tools are described, and first results are presented.

Theoretical Interpretation of Pass 8 Fermi -LAT e + + e - Data

DOE PAGES

Di Mauro, M.; Manconi, S.; Vittino, A.; ...

2017-08-17

The flux of positrons and electrons (e + + e -) has been measured by the Fermi Large Area Telescope (LAT) in the energy range between 7 GeV and 2 TeV. Here, we discuss a number of interpretations of Pass 8 Fermi-LAT e + + e - spectrum, combining electron and positron emission from supernova remnants (SNRs) and pulsar wind nebulae (PWNe), or produced by the collision of cosmic rays (CRs) with the interstellar medium. We also found that the Fermi-LAT spectrum is compatible with the sum of electrons from a smooth SNR population, positrons from cataloged PWNe, and amore » secondary component. If we include in our analysis constraints from the AMS-02 positron spectrum, we obtain a slightly worse fit to the e + + e - Fermi-LAT spectrum, depending on the propagation model. As an additional scenario, we replace the smooth SNR component within 0.7 kpc with the individual sources found in Green's catalog of Galactic SNRs. We find that separate consideration of far and near sources helps to reproduce the e + + e - Fermi-LAT spectrum. However, we show that the fit degrades when the radio constraints on the positron emission from Vela SNR (which is the main contributor at high energies) are taken into account. We find that a break in the power-law injection spectrum at about 100 GeV can also reproduce the measured e + + e -spectrum and, among the CR propagation models that we consider, no reasonable break of the power-law dependence of the diffusion coefficient can modify the electron flux enough to reproduce the observed shape.« less

Theoretical Interpretation of Pass 8 Fermi -LAT e + + e - Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Di Mauro, M.; Manconi, S.; Vittino, A.

The flux of positrons and electrons (e + + e -) has been measured by the Fermi Large Area Telescope (LAT) in the energy range between 7 GeV and 2 TeV. Here, we discuss a number of interpretations of Pass 8 Fermi-LAT e + + e - spectrum, combining electron and positron emission from supernova remnants (SNRs) and pulsar wind nebulae (PWNe), or produced by the collision of cosmic rays (CRs) with the interstellar medium. We also found that the Fermi-LAT spectrum is compatible with the sum of electrons from a smooth SNR population, positrons from cataloged PWNe, and amore » secondary component. If we include in our analysis constraints from the AMS-02 positron spectrum, we obtain a slightly worse fit to the e + + e - Fermi-LAT spectrum, depending on the propagation model. As an additional scenario, we replace the smooth SNR component within 0.7 kpc with the individual sources found in Green's catalog of Galactic SNRs. We find that separate consideration of far and near sources helps to reproduce the e + + e - Fermi-LAT spectrum. However, we show that the fit degrades when the radio constraints on the positron emission from Vela SNR (which is the main contributor at high energies) are taken into account. We find that a break in the power-law injection spectrum at about 100 GeV can also reproduce the measured e + + e -spectrum and, among the CR propagation models that we consider, no reasonable break of the power-law dependence of the diffusion coefficient can modify the electron flux enough to reproduce the observed shape.« less

A Test Apparatus for the MAJORANA DEMONSTRATOR Front-end Electronics

NASA Astrophysics Data System (ADS)

Singh, Harjit; Loach, James; Poon, Alan

2012-10-01

One of the most important experimental programs in neutrino physics is the search for neutrinoless double-beta decay. The MAJORANA collaboration is searching for this rare nuclear process in the Ge-76 isotope using HPGe detectors. Each detector is instrumented with high-performance electronics to read out and amplify the signals. The part of the electronics close to the detectors, consisting of a novel front-end circuit, cables and connectors, is made of radio-pure materials and is exceedingly delicate. In this work a dedicated test apparatus was created to benchmark the performance of the electronics before installation in the experiment. The apparatus was designed for cleanroom use, with fixtures to hold the components without contaminating them, and included the electronics necessary for power and readout. In addition to testing, the station will find longer term use in development of future versions of the electronics.

Radiological considerations for the operation of the Advanced Photon Source storage ring (revised).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moe, H. J.

2002-05-02

This report deals with the radiological considerations of operations using 7700-MeV positron and electron beams in the storage ring (SR) tunnel. The radiological considerations addressed include the following: prompt secondary radiation (bremsstrahlung, giant resonance neutrons, medium and high energy neutrons, and muons) produced by electrons/positrons interacting in a beam stop or by particle losses in the component structures; skyshine radiation, which produces a radiation field in nearby areas and at the nearest off-site location; radioactive gases produced by neutron irradiation of air in the vicinity of a particle loss site; noxious gases (ozone and others) produced in air by themore » escaping bremsstrahlung radiation that results from absorbing particles in the components or by synchrotron radiation escaping into the tunnel; activation of the storage ring components that results in a residual radiation field in the vicinity of these materials following shutdown; potential activation of water used for cooling the magnets and other purposes in the SR tunnel; evaluation of the radiation fields due to escaping synchrotron radiation and gas bremsstrahlung. Estimated dose rates outside of the tunnel, in the early assembly area (EAA), and in the Experiment Hall for several modes of operation (including potential safety envelope beam power, normal beam power, and MCI (maximum credible incident) conditions) have been computed. Shielding in the first optics enclosure (FOE) and for the photon beamlines is discussed in ANL/APS/TB-7 (IPE 93), but additional radiological considerations for the ASD diagnostic beamlines are contained in Appendix C. Although the calculations refer to positrons, electron operation would produce essentially the same effects for the identical assumptions.« less

Electron/proton separation and analysis techniques used in the AMS-02 (e+ + e-) flux measurement

NASA Astrophysics Data System (ADS)

Graziani, Maura; AMS-02 Collaboration

2016-04-01

AMS-02 is a large acceptance cosmic ray detector which has been installed on the International Space Station (ISS) in May 2011, where it is collecting cosmic rays up to TeV energies. The search for Dark Matter indirect signatures in the rare components of the cosmic ray fluxes is among the main objectives of the experiment. AMS-02 is providing cosmic electrons and positrons data with an unprecedented precision. This is achieved by means to the excellent hadron/electron separation power obtained combining the independent measurements from the Transition Radiation Detector, electromagnetic Calorimeter and Tracker detectors. In this contribution we will detail the analysis techniques used to distinguish electrons from the hadronic background and show the in-flight performances of these detectors relevant for the electron/positron measurements.

Theory of waves incoherently scattered

NASA Technical Reports Server (NTRS)

Bauer, P.

1974-01-01

Electromagnetic waves impinging upon a plasma at frequencies larger than the plasma frequency, suffer weak scattering. The scattering arises from the existence of electron density fluctuations. The received signal corresponds to a particular spatial Fourier component of the fluctuations, the wave vector of which is a function of the wavelength of the radiowave. Wavelengths short with respect to the Debye length of the medium relate to fluctuations due to non-interacting Maxwellian electrons, while larger wavelengths relate to fluctuations due to collective Coulomb interactions. In the latter case, the scattered signal exhibits a spectral distribution which is characteristic of the main properties of the electron and ion gases and, therefore, provides a powerful diagnosis of the state of the ionosphere.

Universal Documentation System

DTIC Science & Technology

2012-07-01

Follow preparation instructions in Section 5.2.1 for the entries ITEM NO. and REMARKS. FLOTATION DURATION: Enter flotation duration of the test unit...Teflon, carbon steel, copper and copper alloys, and stainless steel (martensitic, ferritic, austenitic). • Quantity: Enter the quantity of components...DESCRIPTION 1470 ITEM NO.: FLOTATION DURATION: ELECTRONIC AIDS • TYPE: • POWER OUT (WATTS): • FREQUENCY (MHz): C-22 • MODULATION

Embedded Diagnostic/Prognostic Reasoning and Information Continuity for Improved Avionics Maintenance

DTIC Science & Technology

2006-01-01

enabling technologies such as built-in-test, advanced health monitoring algorithms, reliability and component aging models, prognostics methods, and...deployment and acceptance. This framework and vision is consistent with the onboard PHM ( Prognostic and Health Management) as well as advanced... monitored . In addition to the prognostic forecasting capabilities provided by monitoring system power, multiple confounding errors by electronic

78 FR 48203 - Pacific Gas and Electric Company, Humboldt Bay Power Plant, Unit 3, Notice of Public Meeting on...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-07

... electronically from the ADAMS Public Library component on the NRC Web site, http://www.nrc.gov . Persons who do... Agencywide Documents Access and Management System (ADAMS) at accession numbers ML131300009 and ML131300160... Web site at http://www.nrc.gov/public-involve/public-meetings/ . FOR FURTHER INFORMATION CONTACT...

The Impact of Assistive Technology on Curriculum Accommodation for a Braille-Reading Student

ERIC Educational Resources Information Center

Farnsworth, Charles R.; Luckner, John L.

2008-01-01

Over 5 months, the authors evaluated the efficacy of electronic assistive technology (the BrailleNote mPower BT-32 notetaker and Tiger Cub Jr. embosser) and associated software components in creating curriculum materials for a middle school Braille-reading student. The authors collected data at the beginning and end of the study from parents,…

Flexible carbon micro-supercapacitors prepared by direct cw-laser writing

NASA Astrophysics Data System (ADS)

Cai, Jinguang; Watanabe, Akira

2016-03-01

Micro-/nano-scale power supply units with high energy and high power densities are critical components for the development of compact miniaturized portable electronic devices. Supercapacitors have attracted many research attentions due to their high power density, robust cycle performance, pollution-free operation, and maintenance-free features. Besides, the properties of small size, light weight, and flexibility are also required. On-chip microsupercapacitors (MSCs) have the potential acting as power supply units in portable devices, due to their simplified packaging processes and compatibility to the integrated circuits. However, the fabrication methods and materials should be cost-effective, scalable, and compatible to current electronic industry. Carbon materials own high specific surface areas, electrochemical stability, and high electrical conductivity, which are critical parameters for high-power supercapacitors. Moreover, the high mechanical tolerance makes them good candidates for flexible wearable devices. Therefore, MSCs based on carbon materials would satisfy the requirements of portable electronics. In this work, we demonstrated the fabrication of carbon MSCs by laser direct writing on commercial polyimide sheets in Ar with lowcost semiconductor cw-laser with a wavelength of 405nm. The obtained structures are macro-nanostructures comprising graphitized and amorphous carbon with relatively smooth surfaces and low resistance, in compared with the structures obtained by laser writing in air. As-prepared micro-supercapacitors show a high capacitance of about 14.9 mF/cm2 at a scanning rate of 10 mV/s, which is comparable to the reported highest capacitance of carbon-based supercapacitors fabricated by pulse-laser writing.

Superlattice-based thin-film thermoelectric modules with high cooling fluxes

PubMed Central

Bulman, Gary; Barletta, Phil; Lewis, Jay; Baldasaro, Nicholas; Manno, Michael; Bar-Cohen, Avram; Yang, Bao

2016-01-01

In present-day high-performance electronic components, the generated heat loads result in unacceptably high junction temperatures and reduced component lifetimes. Thermoelectric modules can, in principle, enhance heat removal and reduce the temperatures of such electronic devices. However, state-of-the-art bulk thermoelectric modules have a maximum cooling flux qmax of only about 10 W cm−2, while state-of-the art commercial thin-film modules have a qmax <100 W cm−2. Such flux values are insufficient for thermal management of modern high-power devices. Here we show that cooling fluxes of 258 W cm−2 can be achieved in thin-film Bi2Te3-based superlattice thermoelectric modules. These devices utilize a p-type Sb2Te3/Bi2Te3 superlattice and n-type δ-doped Bi2Te3−xSex, both of which are grown heteroepitaxially using metalorganic chemical vapour deposition. We anticipate that the demonstration of these high-cooling-flux modules will have far-reaching impacts in diverse applications, such as advanced computer processors, radio-frequency power devices, quantum cascade lasers and DNA micro-arrays. PMID:26757675

Amping it up on a small budget: Transforming inexpensive, commercial audio and video components into a useful charged particle spectrometer

NASA Astrophysics Data System (ADS)

Pallone, Arthur

Necessity often leads to inspiration. Such was the case when a traditional amplifier quit working during the collection of an alpha particle spectrum. I had a 15 battery-powered audio amplifier in my box of project electronics so I connected it between the preamplifier and the multichannel analyzer. The alpha particle spectrum that appeared on the computer screen matched expectations even without correcting for impedance mismatches. Encouraged by this outcome, I have begun to systematically replace each of the parts in a traditional charged particle spectrometer with audio and video components available through consumer electronics stores with the goal of producing an inexpensive charged particle spectrometer for use in education and research. Hopefully my successes, setbacks, and results to date described in this presentation will inform and inspire others.

Advanced technology component derating

NASA Astrophysics Data System (ADS)

Jennings, Timothy A.

1992-02-01

A technical study performed to determine the derating criteria of advanced technology components is summarized. The study covered existing criteria from AFSC Pamphlet 800-27 and the development of new criteria based on data, literature searches, and the use of advanced technology prediction methods developed in RADC-TR-90-72. The devices that were investigated were as follows: VHSIC, ASIC, MIMIC, Microprocessor, PROM, Power Transistors, RF Pulse Transistors, RF Multi-Transistor Packages, Photo Diodes, Photo Transistors, Opto-Electronic Couplers, Injection Laser Diodes, LED, Hybrid Deposited Film Resistors, Chip Resistors, and Capacitors and SAW devices. The results of the study are additional derating criteria that extend the range of AFSC Pamphlet 800-27. These data will be transitioned from the report to AFSC Pamphlet 800-27 for use by government and contractor personnel in derating electronics systems yielding increased safety margins and improved system reliability.

The Electron Temperature and Anisotropy in the Solar Wind. Comparison of the Core and Halo Populations

NASA Astrophysics Data System (ADS)

Pierrard, V.; Lazar, M.; Poedts, S.; Štverák, Š.; Maksimovic, M.; Trávníček, P. M.

2016-08-01

Estimating the temperature of solar wind particles and their anisotropies is particularly important for understanding the origin of their deviations from thermal equilibrium and the effects this has. In the absence of energetic events, the velocity distribution of electrons reveals a dual structure with a thermal (Maxwellian) core and a suprathermal (kappa) halo. This article presents a detailed observational analysis of these two components, providing estimations of their temperatures and temperature anisotropies, and decoding any potential interdependence that their properties may indicate. The dataset used in this study includes more than 120 000 of the distributions measured by three missions in the ecliptic within an extended range of heliocentric distances from 0.3 to over 4 AU. The core temperature is found to decrease with the radial distance, while the halo temperature slightly increases, clarifying an apparent contradiction in previous observational analyses and providing valuable clues about the temperature of the kappa-distributed populations. For low values of the power-index kappa, these two components manifest a clear tendency to deviate from isotropy in the same direction, which seems to confirm the existence of mechanisms with similar effects on both components, e.g., the solar wind expansion, or the particle heating by the fluctuations. However, the existence of plasma states with anticorrelated anisotropies of the core and halo populations and the increase in their number for high values of the power-index kappa suggest a dynamic interplay of these components, mediated, most probably, by the anisotropy-driven instabilities.

Tools and techniques for estimating high intensity RF effects

NASA Astrophysics Data System (ADS)

Zacharias, Richard L.; Pennock, Steve T.; Poggio, Andrew J.; Ray, Scott L.

1992-01-01

Tools and techniques for estimating and measuring coupling and component disturbance for avionics and electronic controls are described. A finite-difference-time-domain (FD-TD) modeling code, TSAR, used to predict coupling is described. This code can quickly generate a mesh model to represent the test object. Some recent applications as well as the advantages and limitations of using such a code are described. Facilities and techniques for making low-power coupling measurements and for making direct injection test measurements of device disturbance are also described. Some scaling laws for coupling and device effects are presented. A method for extrapolating these low-power test results to high-power full-system effects are presented.

Medium- and Heavy-Duty Vehicle Duty Cycles for Electric Powertrains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelly, Kenneth; Bennion, Kevin; Miller, Eric

2016-03-02

NREL's Fleet Test and Evaluation group has extensive in-use vehicle data demonstrating the importance of understanding the vocational duty cycle for appropriate sizing of electric vehicle (EV) and power electronics components for medium- and heavy-duty EV applications. This presentation includes an overview of recent EV fleet evaluation projects that have valuable in-use data that can be leveraged for sub-system research, analysis, and validation. Peak power and power distribution data from in-field EVs are presented for four different vocations, including class 3 delivery vans, class 6 delivery trucks, class 8 transit buses, and class 8 port drayage trucks, demonstrating the impactsmore » of duty cycle on performance requirements.« less

Tests of Transport Theory and Reduced Impurity Influx with Highly Radiative Plasmas in TFTR

NASA Astrophysics Data System (ADS)

Hill, K. W.

1997-11-01

The electron and ion temperature profiles in beam-heated plasmas were observed to be remarkably invariant when radiative losses were increased significantly through gas puffing of high-Z impurities (argon, krypton, xenon) in the Tokamak Fusion Test Reactor. Without impurity puffing, radiative losses accounted for typically only ~ 25\\char'45 of the input power and the radiation profile was strongly peaked at the plasma edge, where the dominant carbon impurity was not fully stripped. At central electron temperatures, T_eo, of ~ 6 keV, trace concentrations of krypton and xenon (n_z/ne ~ 10-3) generated flat and centrally peaked radiation profiles respectively, and a significant fraction of the input power (45-100\\char'45 ) was lost through radiation. This loss provided a nearly ideal technique for studying local heat transport in tokamaks because it perturbed the net heating profile strongly and in a measureable way, with little effect on the density and the beam deposition profiles. In supershot plasmas, Ti >> T_e, the ion temperature profile remained constant, or even increased modestly, as the radiated power fraction was increased to 75-90\\char'45 with krypton and xenon. This observation is surprising because ion-electron coupling is the dominant power loss term for the ions in the core of supershot plasmas, and the central Ti would have decreased a factor of two if the local ion thermal diffusivity had remained constant at its value without impurity puffing. In L-mode plasmas where ion-electron power coupling is a smaller term in the power balance, the electron temperature during impurity puffing also changed only ~ 10-15\\char'45 even as the net power flow through the electrons was decreased by a factor of ~ 3. The ``stiffness" of the temperature profiles to net input power is supportive of transport mechanisms which have a marginal-stability character. Preliminary comparisons of the temperature changes with predictions of the IFS/PPPL transport model,(M. Kotschenreuther, W. Dorland, M. A. Beer, and G. W. Hammett, Phys. Plasmas 2, 2381 (1995)) which has strong marginal-stability behavior, are reasonable; more detailed comparisons are in progress. Use of high-Z radiators did not impair fusion performance, confirming they can be used to reduce the heat flux to the plasma facing components with minimal ion dilution. At input power level s of 30-33 MW, enhanced radiation through krypton and xenon puffing eliminated serious carbon influx (carbon ``blooms") which occurred in comparable plasmas without impurity puffing.

Next-generation materials for future synchrotron and free-electron laser sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Assoufid, Lahsen; Graafsma, Heinz

We show that the development of new materials and improvements of existing ones are at the root of the spectacular recent developments of new technologies for synchrotron storage rings and free-electron laser sources. This holds true for all relevant application areas, from electron guns to undulators, x-ray optics, and detectors. As demand grows for more powerful and efficient light sources, efficient optics, and high-speed detectors, an overview of ongoing materials research for these applications is timely. In this article, we focus on the most exciting and demanding areas of materials research and development for synchrotron radiation optics and detectors. Materialsmore » issues of components for synchrotron and free-electron laser accelerators are briefly discussed. Lastly, the articles in this issue expand on these topics.« less

Next-generation materials for future synchrotron and free-electron laser sources

DOE PAGES

Assoufid, Lahsen; Graafsma, Heinz

2017-06-09

We show that the development of new materials and improvements of existing ones are at the root of the spectacular recent developments of new technologies for synchrotron storage rings and free-electron laser sources. This holds true for all relevant application areas, from electron guns to undulators, x-ray optics, and detectors. As demand grows for more powerful and efficient light sources, efficient optics, and high-speed detectors, an overview of ongoing materials research for these applications is timely. In this article, we focus on the most exciting and demanding areas of materials research and development for synchrotron radiation optics and detectors. Materialsmore » issues of components for synchrotron and free-electron laser accelerators are briefly discussed. Lastly, the articles in this issue expand on these topics.« less

X-band inverse class-F GaN internally-matched power amplifier

NASA Astrophysics Data System (ADS)

Zhao, Bo-Chao; Lu, Yang; Han, Wen-Zhe; Zheng, Jia-Xin; Zhang, Heng-Shuang; Ma, Pei-jun; Ma, Xiao-Hua; Hao, Yue

2016-09-01

An X-band inverse class-F power amplifier is realized by a 1-mm AlGaN/GaN high electron mobility transistor (HEMT). The intrinsic and parasitic components inside the transistor, especially output capacitor Cds, influence the harmonic impedance heavily at the X-band, so compensation design is used for meeting the harmonic condition of inverse class-F on the current source plane. Experiment results show that, in the continuous-wave mode, the power amplifier achieves 61.7% power added efficiency (PAE), which is 16.3% higher than the class-AB power amplifier realized by the same kind of HEMT. To the best of our knowledge, this is the first inverse class-F GaN internally-matched power amplifier, and the PAE is quite high at the X-band. Project supported by the National High Technology Research and Development Program of China (Grant No. 2015AA016801).

A 5 kA pulsed power supply for inductive and plasma loads in large volume plasma device.

PubMed

Srivastava, P K; Singh, S K; Sanyasi, A K; Awasthi, L M; Mattoo, S K

2016-07-01

This paper describes 5 kA, 12 ms pulsed power supply for inductive load of Electron Energy Filter (EEF) in large volume plasma device. The power supply is based upon the principle of rapid sourcing of energy from the capacitor bank (2.8 F/200 V) by using a static switch, comprising of ten Insulated Gate Bipolar Transistors (IGBTs). A suitable mechanism is developed to ensure equal sharing of current and uniform power distribution during the operation of these IGBTs. Safe commutation of power to the EEF is ensured by the proper optimization of its components and by the introduction of over voltage protection (>6 kV) using an indigenously designed snubber circuit. Various time sequences relevant to different actions of power supply, viz., pulse width control and repetition rate, are realized through optically isolated computer controlled interface.

A 5 kA pulsed power supply for inductive and plasma loads in large volume plasma device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Srivastava, P. K., E-mail: pkumar@ipr.res.in; Singh, S. K.; Sanyasi, A. K.

This paper describes 5 kA, 12 ms pulsed power supply for inductive load of Electron Energy Filter (EEF) in large volume plasma device. The power supply is based upon the principle of rapid sourcing of energy from the capacitor bank (2.8 F/200 V) by using a static switch, comprising of ten Insulated Gate Bipolar Transistors (IGBTs). A suitable mechanism is developed to ensure equal sharing of current and uniform power distribution during the operation of these IGBTs. Safe commutation of power to the EEF is ensured by the proper optimization of its components and by the introduction of over voltagemore » protection (>6 kV) using an indigenously designed snubber circuit. Various time sequences relevant to different actions of power supply, viz., pulse width control and repetition rate, are realized through optically isolated computer controlled interface.« less

Power Balance Estimation in Long Duration Discharges on QUEST

DOE PAGES

Hanada, K.; Zushi, H.; Idei, H.; ...

2016-10-28

Fully non-inductive plasma start-up was successfully achieved by using a well-controlled microwave source on the spherical tokamak, QUEST. Non-inductive plasmas were maintained for approximately 3–5 min, during which time power balance estimates could be achieved by monitoring wall and cooling-water temperatures. Approximately 70%–90% of the injected power could be accounted for by calorimetric measurements and approximately half of the injected power was found to be deposited on the vessel wall, which is slightly dependent on the magnetic configuration. Lastly, the power distribution to water-cooled limiters, which are expected to be exposed to local heat loads, depends significantly on the magneticmore » configuration, however some of the deposited power is due to energetic electrons, which have large poloidal orbits and are likely to be deposited on the plasma facing components.« less

Monolithically Integrated Self-Charging Power Pack Consisting of a Silicon Nanowire Array/Conductive Polymer Hybrid Solar Cell and a Laser-Scribed Graphene Supercapacitor.

PubMed

Liu, Hanhui; Li, Mengping; Kaner, Richard B; Chen, Songyan; Pei, Qibing

2018-05-09

Owing to the need for portable and sustainable energy sources and the development trend for microminiaturization and multifunctionalization in the electronic components, the study of integrated self-charging power packs has attracted increasing attention. A new self-charging power pack consisting of a silicon nanowire array/poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) hybrid solar cell and a laser-scribed graphene (LSG) supercapacitor has been fabricated. The Si nanowire array/PEDOT:PSS hybrid solar cell structure exhibited a high power conversion efficiency (PCE) of 12.37%. The LSG demonstrated excellent energy storage capability for the power pack, with high current density, energy density, and cyclic stability when compared to other supercapacitor electrodes such as active carbon and conducting polymers. The overall efficiency of the power unit is 2.92%.

Power Balance Estimation in Long Duration Discharges on QUEST

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hanada, K.; Zushi, H.; Idei, H.

Fully non-inductive plasma start-up was successfully achieved by using a well-controlled microwave source on the spherical tokamak, QUEST. Non-inductive plasmas were maintained for approximately 3–5 min, during which time power balance estimates could be achieved by monitoring wall and cooling-water temperatures. Approximately 70%–90% of the injected power could be accounted for by calorimetric measurements and approximately half of the injected power was found to be deposited on the vessel wall, which is slightly dependent on the magnetic configuration. Lastly, the power distribution to water-cooled limiters, which are expected to be exposed to local heat loads, depends significantly on the magneticmore » configuration, however some of the deposited power is due to energetic electrons, which have large poloidal orbits and are likely to be deposited on the plasma facing components.« less

Design and power management of an offshore medium voltage DC microgrid realized through high voltage power electronics technologies and control

NASA Astrophysics Data System (ADS)

Grainger, Brandon Michael

The growth in the electric power industry's portfolio of Direct Current (DC) based generation and loads have captured the attention of many leading research institutions. Opportunities for using DC based systems have been explored in electric ship design and have been a proven, reliable solution for transmitting bulk power onshore and offshore. To integrate many of the renewable resources into our existing AC grid, a number of power conversions through power electronics are required to condition the equipment for direct connection. Within the power conversion stages, there is always a requirement to convert to or from DC. The AC microgrid is a conceptual solution proposed for integrating various types of renewable generation resources. The fundamental microgrid requirements include the capability of operating in islanding mode and/or grid connected modes. The technical challenges associated with microgrids include (1) operation modes and transitions that comply with IEEE1547 without extensive custom engineering and (2) control architecture and communication. The Medium Voltage DC (MVDC) architecture, explored by the University of Pittsburgh, can be visualized as a special type of DC microgrid. This dissertation is multi-faceted, focused on many design aspects of an offshore DC microgrid. The focal points of the discussion are focused on optimized high power, high frequency magnetic material performance in electric machines, transformers, and DC/DC power converters---all components found within offshore, power system architectures. A new controller design based upon model reference control is proposed and shown to stabilize the electric motor drives (modeled as constant power loads), which serve as the largest power consuming entities in the microgrid. The design and simulation of a state-of-the-art multilevel converter for High Voltage DC (HVDC) is discussed and a component sensitivity analysis on fault current peaks is explored. A power management routine is proposed and evaluated as the DC microgrid is disturbed through various mode transitions. Finally, two communication protocols are described for the microgrid---one to minimize communication overhead inside the microgrid and another to provide robust and scalable intra-grid communication. The work presented is supported by Asea Brown Boveri (ABB) Corporate Research Center within the Active Grid Infrastructure program, the Advanced Research Project Agency - Energy (ARPA-E) through the Solar ADEPT program, and Mitsubishi Electric Corporation (MELCO).

RECENT DEVELOPMENTS IN HYDROLOGIC INSTRUMENTATION.

USGS Publications Warehouse

Latkovich, Vito J.

1985-01-01

The availability of space-age materials and implementation of state-of-the-art electronics is making possible the recent developments of hydrologic instrumentation. Material developments include: Synthetic-fiber sounding and tag lines; fiberglass wading rod; polymer (plastic) sheaves, pulleys and sampler components; and polymer (plastic) bucket wheels for current meters. These materials are very cost effective and efficient. Electromechanical and electronic developments and applications include: adaptable data acquisition system; downhole sampler for hazardous substances; current-meter digitizer; hydraulic power/drive system for discharge measurements and water-quality sampling; non-contact water-level sensors; minimum data recorder; acoustic velocity meters, and automated current meter discharge-measurement system.

Passive Thermal Control Challenges for Future Exploration Missions

NASA Technical Reports Server (NTRS)

Rickman, Steven L.

2004-01-01

This slide presentation reviews the importance of developing passive thermal control for the future exploration missions envisioned in President Bush's call for human exploration of the Moon and Mars. Included in the presentation is a review of the conditions that make the thermal control very challenging on the Moon and Mars. With the future miniaturization of electronics components, power density and the associated challenges of electronics heat dissipation will provide new challenges. There is a challenge for improvement in modeling and analysis of thermal control systems, and for improved facilities to support testing of thermal-vacuum systems.

System level latchup mitigation for single event and transient radiation effects on electronics

DOEpatents

Kimbrough, J.R.; Colella, N.J.

1997-09-30

A ``blink`` technique, analogous to a person blinking at a flash of bright light, is provided for mitigating the effects of single event current latchup and prompt pulse destructive radiation on a micro-electronic circuit. The system includes event detection circuitry, power dump logic circuitry, and energy limiting measures with autonomous recovery. The event detection circuitry includes ionizing radiation pulse detection means for detecting a pulse of ionizing radiation and for providing at an output terminal thereof a detection signal indicative of the detection of a pulse of ionizing radiation. The current sensing circuitry is coupled to the power bus for determining an occurrence of excess current through the power bus caused by ionizing radiation or by ion-induced destructive latchup of a semiconductor device. The power dump circuitry includes power dump logic circuitry having a first input terminal connected to the output terminal of the ionizing radiation pulse detection circuitry and having a second input terminal connected to the output terminal of the current sensing circuitry. The power dump logic circuitry provides an output signal to the input terminal of the circuitry for opening the power bus and the circuitry for shorting the power bus to a ground potential to remove power from the power bus. The energy limiting circuitry with autonomous recovery includes circuitry for opening the power bus and circuitry for shorting the power bus to a ground potential. The circuitry for opening the power bus and circuitry for shorting the power bus to a ground potential includes a series FET and a shunt FET. The invention provides for self-contained sensing for latchup, first removal of power to protect latched components, and autonomous recovery to enable transparent operation of other system elements. 18 figs.

System level latchup mitigation for single event and transient radiation effects on electronics

DOEpatents

Kimbrough, Joseph Robert; Colella, Nicholas John

1997-01-01

A "blink" technique, analogous to a person blinking at a flash of bright light, is provided for mitigating the effects of single event current latchup and prompt pulse destructive radiation on a micro-electronic circuit. The system includes event detection circuitry, power dump logic circuitry, and energy limiting measures with autonomous recovery. The event detection circuitry includes ionizing radiation pulse detection means for detecting a pulse of ionizing radiation and for providing at an output terminal thereof a detection signal indicative of the detection of a pulse of ionizing radiation. The current sensing circuitry is coupled to the power bus for determining an occurrence of excess current through the power bus caused by ionizing radiation or by ion-induced destructive latchup of a semiconductor device. The power dump circuitry includes power dump logic circuitry having a first input terminal connected to the output terminal of the ionizing radiation pulse detection circuitry and having a second input terminal connected to the output terminal of the current sensing circuitry. The power dump logic circuitry provides an output signal to the input terminal of the circuitry for opening the power bus and the circuitry for shorting the power bus to a ground potential to remove power from the power bus. The energy limiting circuitry with autonomous recovery includes circuitry for opening the power bus and circuitry for shorting the power bus to a ground potential. The circuitry for opening the power bus and circuitry for shorting the power bus to a ground potential includes a series FET and a shunt FET. The invention provides for self-contained sensing for latchup, first removal of power to protect latched components, and autonomous recovery to enable transparent operation of other system elements.

Bohm criterion and plasma particle/power exhaust to and recycling at the wall

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Xianzhu; Guo, Zehua

The plasma particle and power exhaust to the divertor surface drives both particle and power recycling at the surface, which in return constrains the plasma density and temperature at the target and their profile further upstream. Both particle and power exhaust fluxes are mediated by the plasma sheath next to the divertor surface. In particular, the Bohm criterion constrains the ion exit flow speed, which enters directly into the particle flux and the kinetic flow energy component of the ion power flux, and indirectly into the electron power flux through the sheath potential drop. Here we give an overview onmore » how the Bohm speed is set in a general plasma and how it enters power exhaust and power recycling at the divertor surface, and the implication on the correct implementation of sheath boundary conditions in numerical codes. The cases of ideal and non-ideal Bohm speed are distinguished as a result of the physics discussion.« less

Bohm criterion and plasma particle/power exhaust to and recycling at the wall

DOE PAGES

Tang, Xianzhu; Guo, Zehua

2017-06-07

The plasma particle and power exhaust to the divertor surface drives both particle and power recycling at the surface, which in return constrains the plasma density and temperature at the target and their profile further upstream. Both particle and power exhaust fluxes are mediated by the plasma sheath next to the divertor surface. In particular, the Bohm criterion constrains the ion exit flow speed, which enters directly into the particle flux and the kinetic flow energy component of the ion power flux, and indirectly into the electron power flux through the sheath potential drop. Here we give an overview onmore » how the Bohm speed is set in a general plasma and how it enters power exhaust and power recycling at the divertor surface, and the implication on the correct implementation of sheath boundary conditions in numerical codes. The cases of ideal and non-ideal Bohm speed are distinguished as a result of the physics discussion.« less

Spacecraft transformer and inductor design

NASA Technical Reports Server (NTRS)

Mclyman, W. T.

1977-01-01

The conversion process in spacecraft power electronics requires the use of magnetic components which frequently are the heaviest and bulkiest items in the conversion circuit. This handbook pertains to magnetic material selection, transformer and inductor design tradeoffs, transformer design, iron core dc inductor design, toroidal power core inductor design, window utilization factors, regulation, and temperature rise. Relationships are given which simplify and standardize the design of transformers and the analysis of the circuits in which they are used. The interactions of the various design parameters are also presented in simplified form so that tradeoffs and optimizations may easily be made.

Design of a ZVS PWM inverter for a brushless DC motor in an EMA application

NASA Technical Reports Server (NTRS)

Bell, J. Brett; Nelms, R. M.; Shepherd, Michael T.

1993-01-01

The Component Development Division of the Propulsion Laboratory at Marshall Space Flight Center (MSFC) is currently investigating the use of electromechanical actuators for use in space transportation applications such as Thrust Vector Control (TVC). These high power servomechanisms will require rugged, reliable, and compact power electronic modules capable of modulating several hundred amperes of current at up to 270 Vdc. This paper will discuss the design and implementation of a zero-voltage-switched PWM (Pulse Width Modulation) inverter which operates from a 270 Vdc source at currents up to 100 A.

Thermal design verification testing for the ATS-F and -G spacecraft.

NASA Technical Reports Server (NTRS)

Coyle, M.; Greenwell, J.

1972-01-01

There is a wide fluctuation in the internal power dissipation from the components within the earth viewing module (EVM). The electronic component functional reliability required for a two-to-five year mission is the most significant factor for the thermal design criteria. A mathematical thermal model of the EVM and the orbital environment is used to predict the performance of the thermal control system. Comparisons of the results obtained in chamber thermal balance tests with the data computed on the basis of the theoretical model provide the means for validating the thermal design.

Non-Cooled Power System for Venus Lander

NASA Technical Reports Server (NTRS)

Salazar, Denise; Landis, Geoffrey A.; Colozza, Anthony J.

2014-01-01

The Planetary Science Decadal Survey of 2013-2022 stated that the exploration of Venus is of significant interest. Studying the seismic activity of the planet is of particular importance because the findings can be compared to the seismic activity of Earth. Further, the geological and atmospheric properties of Venus will shed light into the past and future of Earth. This paper presents a radioisotope power system (RPS) design for a small low-power Venus lander. The feasibility of the new power system is then compared to that of primary batteries. A requirement for the power source system is to avoid moving parts in order to not interfere with the primary objective of the mission - to collect data about the seismic activity of Venus using a seismometer. The target mission duration of the lander is 117 days, a significant leap from Venera 13, the longest-lived lander on the surface of Venus, which survived for 2 hours. One major assumption for this mission design is that the power source system will not provide cooling to the other components of the lander. This assumption is based on high-temperature electronics technology that will enable the electronics and components of the lander to operate at Venus surface temperature. For the proposed RPS, a customized General Purpose Heat Source Radioisotope Thermoelectric Generator (GPHSRTG) is designed and analyzed. The GPHS-RTG is chosen primarily because it has no moving parts and it is capable of operating for long duration missions on the order of years. This power system is modeled as a spherical structure for a fundamental thermal analysis. The total mass and electrical output of the system are calculated to be 24 kilograms and 26 Watts, respectively. An alternative design for a battery-based power system uses Sodium Sulfur batteries. To deliver a similar electrical output for 117 days, the battery mass is calculated to be 234 kilograms. Reducing mission duration or power required will reduce the required battery mass. Finally, the advantages and disadvantages of both power systems with regard to science return, risk, and cost are briefly compared. The design of the radioisotope power system is considerably riskier because it is novel and would require additional years of further refinement, manufacturing, safety analysis, and testing that the primary batteries do not need. However, the lifetime of the radioisotope power system makes its science return more promising.

Evaluation of a Prototype Low-Cost, Modular, Wireless Electroencephalography (EEG) Headset Design for Widespread Application

DTIC Science & Technology

2016-06-01

therefore did not implement or test actual sensors or electronic components (analog-to-digital conversion, power , and the wireless transmission ...ARL-TR-7703 ● JUNE 2016 US Army Research Laboratory Evaluation of a Prototype Low-Cost, Modular, Wireless Electroencephalography...originator. ARL-TR-7703 ● JUNE 2016 US Army Research Laboratory Evaluation of a Prototype Low-Cost, Modular, Wireless

New World Vistas: Air and Space Power for the 21st Century, Materials Volume.

DTIC Science & Technology

1996-06-01

derivatives from niche (non-silicon) materials: IR sensors, radars, lasers, and high - temperature , adverse-environment electronics. Investment in these...Develop metastable interstitial composites to create extremely high temperatures for destroying chemical biological warfare agents. " Explosives: 1...synthesize of high temperature materials that will be tailored for specific applications/ components. These materials will tend to have microstructures on

Interfacing with an EVA Suit

NASA Technical Reports Server (NTRS)

Ross, Amy

2011-01-01

A NASA spacesuit under the EVA Technology Domain consists of a suit system; a PLSS; and a Power, Avionics, and Software (PAS) system. Ross described the basic functions, components, and interfaces of the PLSS, which consists of oxygen, ventilation, and thermal control subsystems; electronics; and interfaces. Design challenges were reviewed from a packaging perspective. Ross also discussed the development of the PLSS over the last two decades.

An Overview of the MaRIE X-FEL and Electron Radiography LINAC RF Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bradley, Joseph Thomas III; Rees, Daniel Earl; Scheinker, Alexander

The purpose of the Matter-Radiation Interactions in Extremes (MaRIE) facility at Los Alamos National Laboratory is to investigate the performance limits of materials in extreme environments. The MaRIE facility will utilize a 12 GeV linac to drive an X-ray Free-Electron Laser (FEL). Most of the same linac will also be used to perform electron radiography. The main linac is driven by two shorter linacs; one short linac optimized for X-FEL pulses and one for electron radiography. The RF systems have historically been the one of the largest single component costs of a linac. We will describe the details of themore » different types of RF systems required by each part of the linacs. Starting with the High Power RF system, we will present our methodology for the choice of RF system peak power and pulselength with respect to klystron parameters, modulator parameters, performance requirements and relative costs. We will also present an overview of the Low Level RF systems that are proposed for MaRIE and briefly describe their use with some proposed control schemes.« less

Neutral beamline with ion energy recovery based on magnetic blocking of electrons

DOEpatents

Stirling, W.L.

1980-07-01

A neutral beamline generator with energy recovery of the full-energy ion component of the beam based on magnetic blocking of electrons is provided. Ions from a positive ion source are accelerated to the desired beam energy from a slightly positive potential level with respect to ground through a neutralizer cell by means of a negative acceleration voltage. The unneutralized full-energy ion component of the beam exiting the neutralizer are retarded and slightly deflected and the elecrons in the neutralizer are blocked by a magnetic field generated transverse to the beamline. An electron collector in the form of a coaxial cylinder surrounding and protruding axial a few centimeters beyond the neutralizer exit terminates the electrons which exit the neutralizer in an E x B drift to the collector when the collector is biased a few hundred volts positive with respect to the neutralizer voltage. The neutralizer is operated at the negative acceleration voltage. The neutralizer is operated at the negative acceleration voltage, and the deflected full energy ions are decelerated and the charge collected at ground potential thereby expending none of their energy received from the acceleration power supply.

Small Cold Temperature Instrument Packages

NASA Astrophysics Data System (ADS)

Clark, P. E.; Millar, P. S.; Yeh, P. S.; Feng, S.; Brigham, D.; Beaman, B.

We are developing a small cold temperature instrument package concept that integrates a cold temperature power system with ultra low temperature ultra low power electronics components and power supplies now under development into a 'cold temperature surface operational' version of a planetary surface instrument package. We are already in the process of developing a lower power lower temperature version for an instrument of mutual interest to SMD and ESMD to support the search for volatiles (the mass spectrometer VAPoR, Volatile Analysis by Pyrolysis of Regolith) both as a stand alone instrument and as part of an environmental monitoring package. We build on our previous work to develop strategies for incorporating Ultra Low Temperature/Ultra Low Power (ULT/ULP) electronics, lower voltage power supplies, as well as innovative thermal design concepts for instrument packages. Cryotesting has indicated that our small Si RHBD CMOS chips can deliver >80% of room temperature performance at 40K (nominal minimum lunar surface temperature). We leverage collaborations, past and current, with the JPL battery development program to increase power system efficiency in extreme environments. We harness advances in MOSFET technology that provide lower voltage thresholds for power switching circuits incorporated into our low voltage power supply concept. Conventional power conversion has a lower efficiency. Our low power circuit concept based on 'synchronous rectification' could produce stable voltages as low as 0.6 V with 85% efficiency. Our distributed micro-battery-based power supply concept incorporates cold temperature power supplies operating with a 4 V or 8 V battery. This work will allow us to provide guidelines for applying the low temperature, low power system approaches generically to the widest range of surface instruments.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marques, J.G.; Ramos, A.R.; Fernandes, A.C.

The behavior of electronic components and circuits under radiation is a concern shared by the nuclear industry, the space community and the high-energy physics community. Standard commercial components are used as much as possible instead of radiation hard components, since they are easier to obtain and allow a significant reduction of costs. However, these standard components need to be tested in order to determine their radiation tolerance. The Portuguese Research Reactor (RPI) is a 1 MW pool-type reactor, operating since 1961. The irradiation of electronic components and circuits is one area where a 1 MW reactor can be competitive, sincemore » the fast neutron fluences required for testing are in most cases well below 10{sup 16} n/cm{sup 2}. A program was started in 1999 to test electronics components and circuits for the LHC facility at CERN, initially using a dedicated in-pool irradiation device and later a beam line with tailored neutron and gamma filters. Neutron filters are essential to reduce the intensity of the thermal neutron flux, which does not produce significant defects in electronic components but produces unwanted radiation from activation of contacts and packages of integrated circuits and also of the printed circuit boards. In irradiations performed within the line-of-sight of the core of a fission reactor there is simultaneous gamma radiation which complicates testing in some cases. Filters can be used to reduce its importance and separate testing with a pure gamma radiation source can contribute to clarify some irradiation results. Practice has shown the need to introduce several improvements to the procedures and facilities over the years. We will review improvements done in the following areas: - Optimization of neutron and gamma filters; - Dosimetry procedures in mixed neutron / gamma fields; - Determination of hardness parameter and 1 MeV-equivalent neutron fluence; - Temperature measurement and control during irradiation; - Follow-up of reactor power operational fluctuations; - Study of gamma radiation effects only. The fission neutron spectrum can be limitative for some of the tests, as most neutrons are in the 1-2 MeV energy range. Significant progress has been made lately in compact neutron generators using D-D and D-T fusion reactions, achieving higher neutron fluxes and longer lifetime than previously available. The advantages of using compact neutron generators for testing of electronic components and circuits will be also discussed. (authors)« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Staliulionis, Ž.; Jabbari, M.; Hattel, J. H.

The number of electronics used in outdoor environment is constantly growing. The humidity causes about 19 % of all electronics failures and, especially, moisture increases these problems due to the ongoing process of miniaturization and lower power consumption of electronic components. Moisture loads are still not understood well by design engineers, therefore this field has become one of the bottlenecks in the electronics system design. The objective of this paper is to model moisture ingress into an electronics enclosure under isothermal conditions. The moisture diffusion model is based on a 1D quasi-steady state (QSS) approximation for Fick’s second law. Thismore » QSS approach is also described with an electrical analogy which gives a fast tool in modelling of the moisture response. The same QSS method is applied to ambient water vapour variations. The obtained results are compared to an analytical solution and very good agreement is found.« less

Integrated Power Source Grant

NASA Technical Reports Server (NTRS)

2001-01-01

Traditional spacecraft power systems incorporate a solar array energy source, an energy storage element (battery), and battery charge control and bus voltage regulation electronics to provide continuous electrical power for spacecraft systems and instruments. Dedicated power conditioning components provide limited fault isolation between systems and instruments, while a centralized power-switching unit provides spacecraft load control. Battery undervoltage conditions are detected by the spacecraft processor, which removes fault conditions and non-critical loads before permanent battery damage can occur. Cost effective operation of a micro-sat constellation requires a fault tolerant spacecraft architecture that minimizes on-orbit operational costs by permitting autonomous reconfiguration in response to unexpected fault conditions. A new micro-sat power system architecture that enhances spacecraft fault tolerance and improves power system survivability by continuously managing the battery charge and discharge processes on a cell-by-cell basis has been developed. This architecture is based on the Integrated Power Source (US patent 5644207), which integrates dual junction solar cells, Lithium Ion battery cells, and processor based charge control electronics into a structural panel that can be deployed or used to form a portion of the outer shell of a micro-spacecraft. The first generation Integrated Power Source is configured as a one inch thick panel in which prismatic Lithium Ion battery cells are arranged in a 3x7 matrix (26VDC) and a 3x1 matrix (3.7VDC) to provide the required output voltages and load currents. A multi-layer structure holds the battery cells, as well as the thermal insulators that are necessary to protect the Lithium Ion battery cells from the extreme temperatures of the solar cell layer. Independent thermal radiators, located on the back of the panel, are dedicated to the solar cell array, the electronics, and the battery cell array. In deployed panel applications, these radiators maintain the battery cells in an appropriate operational temperature range.

Adaptive Optics System with Deformable Composite Mirror and High Speed, Ultra-Compact Electronics

NASA Astrophysics Data System (ADS)

Chen, Peter C.; Knowles, G. J.; Shea, B. G.

2006-06-01

We report development of a novel adaptive optics system for optical astronomy. Key components are very thin Deformable Mirrors (DM) made of fiber reinforced polymer resins, subminiature PMN-PT actuators, and low power, high bandwidth electronics drive system with compact packaging and minimal wiring. By using specific formulations of fibers, resins, and laminate construction, we are able to fabricate mirror face sheets that are thin (< 2mm), have smooth surfaces and excellent optical shape. The mirrors are not astigmatic and do not develop surface irregularities when cooled. The actuators are small footprint multilayer PMN-PT ceramic devices with large stroke (2- 20 microns), high linearity, low hysteresis, low power, and flat frequency response to >2 KHz. By utilizing QorTek’s proprietary synthetic impendence power supply technology, all the power, control, and signal extraction for many hundreds to 1000s of actuators and sensors can be implemented on a single matrix controller printed circuit board co-mounted with the DM. The matrix controller, in turn requires only a single serial bus interface, thereby obviating the need for massive wiring harnesses. The technology can be scaled up to multi-meter aperture DMs with >100K actuators.

Conceptual design studies of the Electron Cyclotron launcher for DEMO reactor

NASA Astrophysics Data System (ADS)

Moro, Alessandro; Bruschi, Alex; Franke, Thomas; Garavaglia, Saul; Granucci, Gustavo; Grossetti, Giovanni; Hizanidis, Kyriakos; Tigelis, Ioannis; Tran, Minh-Quang; Tsironis, Christos

2017-10-01

A demonstration fusion power plant (DEMO) producing electricity for the grid at the level of a few hundred megawatts is included in the European Roadmap [1]. The engineering design and R&D for the electron cyclotron (EC), ion cyclotron and neutral beam systems for the DEMO reactor is being performed by Work Package Heating and Current Drive (WPHCD) in the framework of EUROfusion Consortium activities. The EC target power to the plasma is about 50 MW, in which the required power for NTM control and burn control is included. EC launcher conceptual design studies are here presented, showing how the main design drivers of the system have been taken into account (physics requirements, reactor relevant operations, issues related to its integration as in-vessel components). Different options for the antenna are studied in a parameters space including a selection of frequencies, injection angles and launch points to get the best performances for the antenna configuration, using beam tracing calculations to evaluate plasma accessibility and deposited power. This conceptual design studies comes up with the identification of possible limits, constraints and critical issues, essential in the selection process of launcher setup solution.

A 65nm CMOS low-power MedRadio-band integer-N cascaded phase-locked loop for implantable medical systems.

PubMed

Wang, Yi-Xiao; Chen, Wei-Ming; Wu, Chung-Yu

2014-01-01

This paper presents a low-power MedRadio-band integer-N phase-locked Loop (PLL) system which is composed of two charge-pump PLLs cascade connected. The PLL provides the operation clock and local carrier signals for an implantable medical electronic system. In addition, to avoid the off-chip crystal oscillator, the 13.56 MHz Industrial, Scientific and Medical (ISM) band signal from the wireless power transmission system is adopted as the input reference signal for the PLL. Ring-based voltage controlled oscillators (VCOs) with current control units are adopted to reduce chip area and power dissipation. The proposed cascaded PLL system is designed and implemented in TSMC 65-nm CMOS technology. The measured jitter for 216.96 MHz signal is 12.23 ps and the phase noise is -65.9 dBc/Hz at 100 kHz frequency offset under 402.926 MHz carrier frequency. The measured power dissipations are 66 μW in the first PLL and 195 μW in the whole system under 1-V supply voltage. The chip area is 0.1088 mm(2) and no off-chip component is required which is suitable for the integration of the implantable medical electronic system.

Neptune's inner magnetosphere and aurora: Energetic particle constraints

NASA Technical Reports Server (NTRS)

Mauk, B. H.; Krimigis, S. M.; Acuna, M. H.

1994-01-01

A dramatic and peculiar dropout of greater than 500-keV ions (but not electrons) was observed within Neptune's inner magnetosphere near 2 R(sub N) as the Voyager 2 spacecraft approached the planet. Unlike a number of other energetic particle features this feature could not be accounted for by known material bodies in the context of the most utilized magnetic field models (neither the offset tilted dipole models nor the spehrical harmonic model 'O8'). However, the configuration of Neptune's inner magnetosphere is highly uncertain. By applying a novel technique, utilizing energetic particle measurements, to constrain the magnetic field configuration of the inner regions, we show that appeals to unobserved materials within Neptune's system are unnecessary, and that the ion dropout feature was, in all likelihood, the result of ion interactions with maximum L excursions of the ring 1989N1R. The constraints also favor the se of the M2 magnetic field model (Selesnick, 1992) over the previous models. An electron feature was probably absent because the electron interactions with the ring occurred substantially before the ion interactions (about 2 hours for the electrons versus a few minutes for the ions). Pitch-angle scattering apparently eliminated the electron signature. Minimum scattering rates determined based on this premise yield enough electron precipitation power to explain the brightest component of Neptune's aurora. We propose that this bright component is analogous to the Earth's diffuse aurora.

Flexible and stretchable power sources for wearable electronics

PubMed Central

Zamarayeva, Alla M.; Ostfeld, Aminy E.; Wang, Michael; Duey, Jerica K.; Deckman, Igal; Lechêne, Balthazar P.; Davies, Greg; Steingart, Daniel A.; Arias, Ana Claudia

2017-01-01

Flexible and stretchable power sources represent a key technology for the realization of wearable electronics. Developing flexible and stretchable batteries with mechanical endurance that is on par with commercial standards and offer compliance while retaining safety remains a significant challenge. We present a unique approach that demonstrates mechanically robust, intrinsically safe silver-zinc batteries. This approach uses current collectors with enhanced mechanical design, such as helical springs and serpentines, as a structural support and backbone for all battery components. We show wire-shaped batteries based on helical band springs that are resilient to fatigue and retain electrochemical performance over 17,000 flexure cycles at a 0.5-cm bending radius. Serpentine-shaped batteries can be stretched with tunable degree and directionality while maintaining their specific capacity. Finally, the batteries are integrated, as a wearable device, with a photovoltaic module that enables recharging of the batteries. PMID:28630897

Preparation of herpes simplex virus-infected primary neurons for transmission electron microscopy.

PubMed

Miranda-Saksena, Monica; Boadle, Ross; Cunningham, Anthony L

2014-01-01

Transmission electron microscopy (TEM) provides the resolution necessary to identify both viruses and subcellular components of cells infected with many types of viruses, including herpes simplex virus. Recognized as a powerful tool in both diagnostic and research-based virology laboratories, TEM has made possible the identification of new viruses and has contributed to the elucidation of virus life cycle and virus-host cell interaction. Whilst there are many sample preparation techniques for TEM, conventional processing using chemical fixation and resin embedding remains a useful technique, available in virtually all EM laboratories, for studying virus/cell ultrastructure. In this chapter, we describe the preparation of herpes simplex virus-infected primary neurons, grown on plastic cover slips, to allow sectioning of neurons and axons in their growth plane. This technique allows TEM examination of cell bodies, axons, growth cones, and varicosities, providing powerful insights into virus-cell interaction.

Performance of Surface-Mount Ceramic and Solid Tantalum Capacitors for Cryogenic Applications

NASA Technical Reports Server (NTRS)

Patterson, Richard L.; MacDonald, Thomas L.; Hammoud, Ahmad; Gerber, Scott

1998-01-01

Low temperature electronics are of great interest for space exploration programs. These include missions to the outer planets, earth-orbiting and deep-space probes, remote-sensing and communication satellites. Terrestrial applications would also benefit from the availability of low temperature electronics. Power components capable of low temperature operation would, thus, enhance the technologies needed for the development of advanced power systems suitable for use in harsh environments. In this work, ceramic and solid tantalum capacitors were evaluated in terms of their dielectric properties as a function of temperature and at various frequencies. The surface-mount devices were characterized in terms of their capacitance stability and dissipation factor in the frequency range of 50 Hz to 100 kHz at temperatures ranging from room temperature (20 deg. C) to about liquid nitrogen temperature (-190 deg. C). The results are discussed and conclusions made concerning the suitability of the capacitors investigated for low temperature applications.

Computing in the presence of soft bit errors. [caused by single event upset on spacecraft

NASA Technical Reports Server (NTRS)

Rasmussen, R. D.

1984-01-01

It is shown that single-event-upsets (SEUs) due to cosmic rays are a significant source of single bit error in spacecraft computers. The physical mechanism of SEU, electron hole generation by means of Linear Energy Transfer (LET), it discussed with reference made to the results of a study of the environmental effects on computer systems of the Galileo spacecraft. Techniques for making software more tolerant of cosmic ray effects are considered, including: reducing the number of registers used by the software; continuity testing of variables; redundant execution of major procedures for error detection; and encoding state variables to detect single-bit changes. Attention is also given to design modifications which may reduce the cosmic ray exposure of on-board hardware. These modifications include: shielding components operating in LEO; removing low-power Schottky parts; and the use of CMOS diodes. The SEU parameters of different electronic components are listed in a table.

QPPM receiver for free-space laser communications

NASA Technical Reports Server (NTRS)

Budinger, J. M.; Mohamed, J. H.; Nagy, L. A.; Lizanich, P. J.; Mortensen, D. J.

1994-01-01

A prototype receiver developed at NASA Lewis Research Center for direct detection and demodulation of quaternary pulse position modulated (QPPM) optical carriers is described. The receiver enables dual-channel communications at 325-Megabits per second (Mbps) per channel. The optical components of the prototype receiver are briefly described. The electronic components, comprising the analog signal conditioning, slot clock recovery, matched filter and maximum likelihood data recovery circuits are described in more detail. A novel digital symbol clock recovery technique is presented as an alternative to conventional analog methods. Simulated link degradations including noise and pointing-error induced amplitude variations are applied. The bit-error-rate performance of the electronic portion of the prototype receiver under varying optical signal-to-noise power ratios is found to be within 1.5-dB of theory. Implementation of the receiver as a hybrid of analog and digital application specific integrated circuits is planned.

The power of exact conditions in electronic structure theory

NASA Astrophysics Data System (ADS)

Bartlett, Rodney J.; Ranasinghe, Duminda S.

2017-02-01

Once electron correlation is included in an effective one-particle operator, one has a correlated orbital theory (COT). One such theory is Kohn-Sham density functional theory (KS-DFT), but there are others. Such methods have the prospect to redefine traditional Molecular Orbital (MO) theory by building a quantitative component upon its conceptual framework. This paper asks the question what conditions should such a theory satisfy and can this be accomplished? One such condition for a COT is that the orbital eigenvalues should satisfy an ionization theorem that generalizes Koopmans' approximation to the exact principal ionization potentials for every electron in a molecule. Guided by this principle, minimal parameterizations of KS-DFT are made that provide a good approximation to a quantitative MO theory.

The spectrum of electron content fluctuations in the ionosphere.

NASA Technical Reports Server (NTRS)

Titheridge, J. E.

1971-01-01

Continuous records of the electron content of the ionosphere, from 1965 to 1970, are used to obtain power spectra covering periods from 30 sec to 2 yr at latitudes of 34 deg S and 42 deg S. At periods up to 5 min amplitudes were less than 0.2% of the total electron content. Variations produced by gravity waves were very common in the range from 20 to 80 min, with no preferred periods. The amplitude increased during the day, particularly in winter when periodic components predominated. The cutoff at about 17 min was sharply defined, giving a mean scale height for the neutral atmosphere of about 43 km in summer, 47 km on winter days, and 42 km on winter nights.

Establishing the spectral turnover of blazar PKS 2155-304 as an outcome of radiative losses

NASA Astrophysics Data System (ADS)

Jagan, Sitha K.; Sahayanathan, S.; Misra, R.; Ravikumar, C. D.; Jeena, K.

2018-07-01

The broad-band optical/UV and X-ray spectra of blazars have been often modelled as synchrotron component arising from a broken power-law distribution of electrons. A broken power-law distribution is expected, since the high-energy electrons undergo radiative losses effectively. The change in the energy index should then be ≈1 and corresponds to a spectral index difference of 0.5. However, one of the long outstanding problems has been that the observed index change is significantly different. On the other hand, recent high-quality observations of blazars suggest that their local spectra may not be a power law, instead have a slight curvature and often represented by a log-parabola model. Using XMM-Newtonobservations spanning over 12 yr for the BL Lac PKS 2155-304, we show that the optical/UV and X-ray spectra can be well represented by a broken log-parabola model. Further, we show that such a spectrum can indicate the energy dependence of the electron escape time-scale from the main acceleration zone. This novel approach, besides addressing the observed difference in the photon spectral indices, also tries to explain the spectral turn over in far-UV/soft X-rays as a result of the radiative losses.

Functional energy nanocomposites surfaces based on mesoscopic microspheres, polymers and graphene flakes

NASA Astrophysics Data System (ADS)

Alekseev, S. A.; Dmitriev, A. S.; Dmitriev, A. A.; Makarov, P. G.; Mikhailova, I. A.

2017-11-01

In recent years, there has been a great interest in the development and creation of new functional energy materials, including for improving the energy efficiency of power equipment and for effectively removing heat from energy devices, microelectronics and optoelectronics (power micro electronics, supercapacitors, cooling of processors, servers and Data centers). In this paper, the technology of obtaining a new nanocomposite based on mesoscopic microspheres, polymers and graphene flakes is considered. The methods of sequential production of functional materials from graphite flakes of different volumetric concentration using polymers based on epoxy resins and polyimide, as well as the addition of a mesoscopic medium in the form of monodisperse microspheres are described. The data of optical and electron microscopy of such nanocomposites are presented, the main problems in the appearance of defects in such materials are described, the possibilities of their elimination by the selection of different concentrations and sizes of the components. Data are given on the measurement of the hysteresis of the contact angle and the evaporation of droplets on similar substrates. The results of studying the mechanical, electrophysical and thermal properties of such nanocomposites are presented. Particular attention is paid to the investigation of the thermal conductivity of these nanocomposites with respect to the creation of thermal interface materials for cooling devices of electronics, optoelectronics and power engineering.

Establishing the spectral turnover of blazar PKS 2155-304 as an outcome of radiative losses

NASA Astrophysics Data System (ADS)

Jagan, Sitha K.; Sahayanathan, S.; Misra, R.; Ravikumar, C. D.; Jeena, K.

2018-06-01

The broad-band optical/UV and X-ray spectra of blazars have been often modelled as synchrotron component arising from a broken power-law distribution of electrons. A broken power-law distribution is expected, since the high energy electrons undergo radiative losses effectively. The change in the energy index should then be ≈1 and corresponds to a spectral index difference of 0.5. However, one of the long outstanding problems has been that the observed index change is significantly different. On the other hand, recent high quality observations of blazars suggest that their local spectra may not be a power-law, instead have a slight curvature and often represented by a log parabola model. Using XMM-Newton observations spanning over 12 years for the BL Lac PKS 2155-304, we show that the optical/UV and X-ray spectra can be well represented by a broken log parabola model. Further, we show that such a spectrum can indicate the energy dependence of the electron escape time-scale from the main acceleration zone. This novel approach, besides addressing the observed difference in the photon spectral indices, also tries to explain the spectral turn over in far-UV/soft X-rays as a result of the radiative losses.

Magnetohydrodynamic modeling of three Van Allen Probes storms in 2012 and 2013

NASA Astrophysics Data System (ADS)

Paral, J.; Hudson, M. K.; Kress, B. T.; Wiltberger, M. J.; Wygant, J. R.; Singer, H. J.

2015-08-01

Coronal mass ejection (CME)-shock compression of the dayside magnetopause has been observed to cause both prompt enhancement of radiation belt electron flux due to inward radial transport of electrons conserving their first adiabatic invariant and prompt losses which at times entirely eliminate the outer zone. Recent numerical studies suggest that enhanced ultra-low frequency (ULF) wave activity is necessary to explain electron losses deeper inside the magnetosphere than magnetopause incursion following CME-shock arrival. A combination of radial transport and magnetopause shadowing can account for losses observed at radial distances into L = 4.5, well within the computed magnetopause location. We compare ULF wave power from the Electric Field and Waves (EFW) electric field instrument on the Van Allen Probes for the 8 October 2013 storm with ULF wave power simulated using the Lyon-Fedder-Mobarry (LFM) global magnetohydrodynamic (MHD) magnetospheric simulation code coupled to the Rice Convection Model (RCM). Two other storms with strong magnetopause compression, 8-9 October 2012 and 17-18 March 2013, are also examined. We show that the global MHD model captures the azimuthal magnetosonic impulse propagation speed and amplitude observed by the Van Allen Probes which is responsible for prompt acceleration at MeV energies reported for the 8 October 2013 storm. The simulation also captures the ULF wave power in the azimuthal component of the electric field, responsible for acceleration and radial transport of electrons, at frequencies comparable to the electron drift period. This electric field impulse has been shown to explain observations in related studies (Foster et al., 2015) of electron acceleration and drift phase bunching by the Energetic Particle, Composition, and Thermal Plasma Suite (ECT) instrument on the Van Allen Probes.

Linking the micro and macro: L-H transition dynamics and threshold physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malkov, M. A., E-mail: mmalkov@ucsd.edu; Diamond, P. H.; Miki, K.

2015-03-15

The links between the microscopic dynamics and macroscopic threshold physics of the L → H transition are elucidated. Emphasis is placed on understanding the physics of power threshold scalings, and especially on understanding the minimum in the power threshold as a function of density P{sub thr} (n). By extending a numerical 1D model to evolve both electron and ion temperatures, including collisional coupling, we find that the decrease in P{sub thr} (n) along the low-density branch is due to the combination of an increase in collisional electron-to-ion energy transfer and an increase in the heating fraction coupled to the ions.more » Both processes strengthen the edge diamagnetic electric field needed to lock in the mean electric field shear for the L→H transition. The increase in P{sub thr} (n) along the high-density branch is due to the increase with ion collisionality of damping of turbulence-driven shear flows. Turbulence driven shear flows are needed to trigger the transition by extracting energy from the turbulence. Thus, we identify the critical transition physics components of the separatrix ion heat flux and the zonal flow excitation. The model reveals a power threshold minimum in density scans as a crossover between the threshold decrease supported by an increase in heat fraction received by ions (directly or indirectly, from electrons) and a threshold increase, supported by the rise in shear flow damping. The electron/ion heating mix emerges as important to the transition, in that it, together with electron-ion coupling, regulates the edge diamagnetic electric field shear. The importance of possible collisionless electron-ion heat transfer processes is explained.« less

A Charge Sensitive Pre-Amplifier for Smart Point-of-Care Devices Employing Polymer Based Lab-on-a-Chip

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Hanfeng; Britton, Charles; Quaiyum, Farhan

With increasing emphasis on implantable and portable medical devices, low-power, small-chip-area sensor readout system realized in lab-on-a-chip (LOC) platform is gaining more and more importance these days. The main building blocks of the LOC system include a front-end transducer that generates an electrical signal in response to the presence of an analyte of interest, signal processing electronics to process the signal to comply with a specific transmission protocol and a low-power transmitter, all realized in a single integrated circuit platform. Low power consumption and compactness of the components are essential requirements of the LOC system. This paper presents a novelmore » charge sensitive pre-amplifier developed in a standard 180-nm CMOS process suitable for implementing in an LOC platform. The pre-amplifier converts the charge generated by a pyroelectric transducer into a voltage signal, which provides a measurement of the temperature variation in biological fluids. The proposed design is capable of providing 0.8-mV/pC gain while consuming only 2.1 μW of power. Finally, the pre-amplifier composed of integrated components occupies an area of 0.038 mm 2.« less

Sizing Power Components of an Electrically Driven Tail Cone Thruster and a Range Extender

NASA Technical Reports Server (NTRS)

Jansen, Ralph H.; Bowman, Cheryl; Jankovsky, Amy

2016-01-01

The aeronautics industry has been challenged on many fronts to increase efficiency, reduce emissions, and decrease dependency on carbon-based fuels. The NASA Aeronautics Research Mission Directorate has identified a suite of investments to meet long term research demands beyond the purview of commercial investment. Electrification of aviation propulsion through turboelectric or hybrid electric propulsion is one of many exciting research areas which has the potential to revolutionize the aviation industry. This paper will provide an overview of the turboelectric and hybrid electric technologies being developed under NASAs Advanced Air Transportation Technology (AATT) Project, and how these technologies can impact vehicle design. An overview will be presented of vehicle system studies and the electric drive system assumptions for successful turboelectric and hybrid electric propulsion in single aisle size commercial aircraft. Key performance parameters for electric drive system technologies will be reviewed, and the technical investment made in materials, electric machines, power electronics, and integrated power systems will be discussed. Finally, power components for a single aisle turboelectric aircraft with an electrically driven tail cone thruster and a hybrid electric nine passenger aircraft with a range extender will be parametrically sized.

A Charge Sensitive Pre-Amplifier for Smart Point-of-Care Devices Employing Polymer Based Lab-on-a-Chip

DOE PAGES

Wang, Hanfeng; Britton, Charles; Quaiyum, Farhan; ...

2018-01-01

With increasing emphasis on implantable and portable medical devices, low-power, small-chip-area sensor readout system realized in lab-on-a-chip (LOC) platform is gaining more and more importance these days. The main building blocks of the LOC system include a front-end transducer that generates an electrical signal in response to the presence of an analyte of interest, signal processing electronics to process the signal to comply with a specific transmission protocol and a low-power transmitter, all realized in a single integrated circuit platform. Low power consumption and compactness of the components are essential requirements of the LOC system. This paper presents a novelmore » charge sensitive pre-amplifier developed in a standard 180-nm CMOS process suitable for implementing in an LOC platform. The pre-amplifier converts the charge generated by a pyroelectric transducer into a voltage signal, which provides a measurement of the temperature variation in biological fluids. The proposed design is capable of providing 0.8-mV/pC gain while consuming only 2.1 μW of power. Finally, the pre-amplifier composed of integrated components occupies an area of 0.038 mm 2.« less

New strategies for SHM based on a multichannel wireless AE node

NASA Astrophysics Data System (ADS)

Godinez-Azcuaga, Valery; Ley, Obdulia

2014-03-01

This paper discusses the development of an Acoustic Emission (AE) wireless node and its application for SHM (Structural Health Monitoring). The instrument development was planned for applications monitoring steel and concrete bridges components. The final product, now commercially available, is a sensor node which includes multiple sensing elements, on board signal processing and analysis capabilities, signal conditioning electronics, power management circuits, wireless data transmission element and energy harvesting unit. The sensing elements are capable of functioning in both passive and active modes, while the multiple parametric inputs are available for connecting various sensor types to measure external characteristics affecting the performance of the structure under monitoring. The output of all these sensors are combined and analyzed at the node in order to minimize the data transmission rate, which consumes significant amount of power. Power management circuits are used to reduce the data collection intervals through selective data acquisition strategies and minimize the sensor node power consumption. This instrument, known as the 1284, is an excellent platform to deploy SHM in the original bridge applications, but initial prototypes has shown significant potential in monitoring composite wind turbine blades and composites mockups of Unmanned Autonomous Vehicles (UAV) components; currently we are working to extend the use of this system to fields such as coal flow, power transformer, and off-shore platform monitoring.

Pamela observational capabilities of Jovian electrons component

NASA Astrophysics Data System (ADS)

di Felice, V.; PAMELA Collaboration

PAMELA is a satellite-borne experiment that will be launched in the first half of 2006 It will make long duration measurements of cosmic radiation over an extended energy range 80Mev to 200 GeV Specifically PAMELA will measure the cosmic-ray antiproton and positron spectra over the largest energy range ever achieved 80MeV -- 190 GeV and will search for antinuclei with unprecedented sensitivity Furthermore it will measure the light nuclear component of cosmic rays and investigate phenomena connected with solar and earth physics The apparatus consists of a time of flight system a magnetic spectrometer an electromagnetic imaging calorimeter a shower tail catcher scintillator a neutron detector and an anticoincidence system In this work a study of the PAMELA capabilities to detect Jovian electrons is presented The Jovian magnetosphere is a powerful accelerator of electrons to several tens of MeV as observed at first by Pioneer 10 spacecraft 1973 The propagation of Jovian electrons to Earth is affected by modulation due to Corotating Interaction Regions CIR Their flux at Earth is moreover modulated because every sim 13 months Earth and Jupiter are aligned along the average direction of the Parker spiral of the Interplanetary Magnetic Field PAMELA will be able to measure the high energy tail of the Jovian electrons in the energy range from 50 MeV up to 130 MeV Moreover it will be possible to extract the Jovian component reaccelated at the solar wind termination shock above 130 MeV up to 2 GeV from the galactic flux

Detector Powering in the 21st Century Why stay stuck with the Good old 20th Century methods?

NASA Astrophysics Data System (ADS)

Dhawan, Satish; Sumner, Richard

Future Collider Physics Detectors are envisioned with large granularity but we have a power delivery problem unless we fill a large fraction of the detector volume with copper conductors. LHC detector electronics is powered by transporting direct current over distances of 30 to 150 meters. This is how Thomas Alva Edison powered his light bulb. For example, CMS ECAL uses 50 kiloamps at 2.5 volts, supplied over a cable set with a transmission efficiency of only 30%. The transmission loss becomes waste heat in the detector that has to be removed. We have been exploring methods to transmit the DC power at higher voltage (low current), reducing to the final low voltage (high current) using DC-DC converters. These converters must operate in high magnetic fields and high radiation levels. This requires rad hard components and non-magnetic (air core) inductors.

Price percolation model

NASA Astrophysics Data System (ADS)

Kanai, Yasuhiro; Abe, Keiji; Seki, Yoichi

2015-06-01

We propose a price percolation model to reproduce the price distribution of components used in industrial finished goods. The intent is to show, using the price percolation model and a component category as an example, that percolation behaviors, which exist in the matter system, the ecosystem, and human society, also exist in abstract, random phenomena satisfying the power law. First, we discretize the total potential demand for a component category, considering it a random field. Second, we assume that the discretized potential demand corresponding to a function of a finished good turns into actual demand if the difficulty of function realization is less than the maximum difficulty of the realization. The simulations using this model suggest that changes in a component category's price distribution are due to changes in the total potential demand corresponding to the lattice size and the maximum difficulty of realization, which is an occupation probability. The results are verified using electronic components' sales data.

Theoretical Interpretation of Pass 8 Fermi -LAT e {sup +} + e {sup −} Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Di Mauro, M.; Manconi, S.; Donato, F.

The flux of positrons and electrons ( e {sup +} + e {sup −}) has been measured by the Fermi Large Area Telescope (LAT) in the energy range between 7 GeV and 2 TeV. We discuss a number of interpretations of Pass 8 Fermi -LAT e {sup +} + e {sup −} spectrum, combining electron and positron emission from supernova remnants (SNRs) and pulsar wind nebulae (PWNe), or produced by the collision of cosmic rays (CRs) with the interstellar medium. We find that the Fermi -LAT spectrum is compatible with the sum of electrons from a smooth SNR population, positronsmore » from cataloged PWNe, and a secondary component. If we include in our analysis constraints from the AMS-02 positron spectrum, we obtain a slightly worse fit to the e {sup +} + e {sup −} Fermi -LAT spectrum, depending on the propagation model. As an additional scenario, we replace the smooth SNR component within 0.7 kpc with the individual sources found in Green’s catalog of Galactic SNRs. We find that separate consideration of far and near sources helps to reproduce the e {sup +} + e {sup −} Fermi -LAT spectrum. However, we show that the fit degrades when the radio constraints on the positron emission from Vela SNR (which is the main contributor at high energies) are taken into account. We find that a break in the power-law injection spectrum at about 100 GeV can also reproduce the measured e {sup +} + e {sup −} spectrum and, among the CR propagation models that we consider, no reasonable break of the power-law dependence of the diffusion coefficient can modify the electron flux enough to reproduce the observed shape.« less

Packaging printed circuit boards: A production application of interactive graphics

NASA Technical Reports Server (NTRS)

Perrill, W. A.

1975-01-01

The structure and use of an Interactive Graphics Packaging Program (IGPP), conceived to apply computer graphics to the design of packaging electronic circuits onto printed circuit boards (PCB), were described. The intent was to combine the data storage and manipulative power of the computer with the imaginative, intuitive power of a human designer. The hardware includes a CDC 6400 computer and two CDC 777 terminals with CRT screens, light pens, and keyboards. The program is written in FORTRAN 4 extended with the exception of a few functions coded in COMPASS (assembly language). The IGPP performs four major functions for the designer: (1) data input and display, (2) component placement (automatic or manual), (3) conductor path routing (automatic or manual), and (4) data output. The most complex PCB packaged to date measured 16.5 cm by 19 cm and contained 380 components, two layers of ground planes and four layers of conductors mixed with ground planes.

A 4 K tactical cryocooler using reverse-Brayton machines

NASA Astrophysics Data System (ADS)

Zagarola, M.; Cragin, K.; McCormick, J.; Hill, R.

2017-12-01

Superconducting electronics and spectral-spatial holography have the potential to revolutionize digital communications, but must operate at cryogenic temperatures, near 4 K. Liquid helium is undesirable for military missions due to logistics and scarcity, and commercial low temperature cryocoolers are unable to meet size, weight, power, and environmental requirements for many missions. To address this need, Creare is developing a reverse turbo-Brayton cryocooler that provides refrigeration at 4.2 K and rejects heat at 77 K to an upper-stage cryocooler or through boil-off of liquid nitrogen. The cooling system is predicted to reduce size, weight, and input power by at least an order of magnitude as compared to the current state-of-the-art 4.2 K cryocooler. For systems utilizing nitrogen boil-off, the boil-off rate is reasonable. This paper reviews the design of the cryocooler, the key components, and component test results.

Low-cost, high-fidelity, adaptive cancellation of periodic 60 Hz noise.

PubMed

Wesson, Kyle D; Ochshorn, Robert M; Land, Bruce R

2009-12-15

A common method to eliminate unwanted power line interference in neurobiology laboratories where sensitive electronic signals are measured is with a notch filter. However a fixed-frequency notch filter cannot remove all power line noise contamination since inherent frequency and phase variations exist in the contaminating signal. One way to overcome the limitations of a fixed-frequency notch filter is with adaptive noise cancellation. Adaptive noise cancellation is an active approach that uses feedback to create a signal that when summed with the contaminated signal destructively interferes with the noise component leaving only the desired signal. We have implemented an optimized least mean square adaptive noise cancellation algorithm on a low-cost 16 MHz, 8-bit microcontroller to adaptively cancel periodic 60 Hz noise. In our implementation, we achieve between 20 and 25 dB of cancellation of the fundamental 60 Hz noise component.

The NASA computer aided design and test system

NASA Technical Reports Server (NTRS)

Gould, J. M.; Juergensen, K.

1973-01-01

A family of computer programs facilitating the design, layout, evaluation, and testing of digital electronic circuitry is described. CADAT (computer aided design and test system) is intended for use by NASA and its contractors and is aimed predominantly at providing cost effective microelectronic subsystems based on custom designed metal oxide semiconductor (MOS) large scale integrated circuits (LSIC's). CADAT software can be easily adopted by installations with a wide variety of computer hardware configurations. Its structure permits ease of update to more powerful component programs and to newly emerging LSIC technologies. The components of the CADAT system are described stressing the interaction of programs rather than detail of coding or algorithms. The CADAT system provides computer aids to derive and document the design intent, includes powerful automatic layout software, permits detailed geometry checks and performance simulation based on mask data, and furnishes test pattern sequences for hardware testing.

Non-Equilibrium Phenomena in High Power Beam Materials Processing

NASA Astrophysics Data System (ADS)

Tosto, Sebastiano

2004-03-01

The paper concerns some aspects of non-equilibrium materials processing with high power beams. Three examples show that the formation of metastable phases plays a crucial role to understand the effects of beam-matter interaction: (i) modeling of pulsed laser induced thermal sputtering; (ii) formation of metastable phases during solidification of the melt pool; (i) possibility of carrying out heat treatments by low power irradiation ``in situ''. The case (i) deals with surface evaporation and boiling processes in presence of superheating. A computer simulation model of thermal sputtering by vapor bubble nucleation in molten phase shows that non-equilibrium processing enables the rise of large surface temperature gradients in the boiling layer and the possibility of sub-surface temperature maximum. The case (ii) concerns the heterogeneous welding of Cu and AISI 304L stainless steel plates by electron beam irradiation. Microstructural investigation of the molten zone has shown that dwell times of the order of 10-1-10-3 s, consistent with moderate cooling rates in the range 10^3-10^5 K/s, entail the formation of metastable Cu-Fe phases. The case (iii) concerns electron beam welding and post-welding treatments of 2219 Al base alloy. Electron microscopy and positron annihilation have explained why post-weld heat transients induced by low power irradiation of specimens in the as welded condition enable ageing effects usually expected after some hours of treatment in furnace. The problem of microstructural instability is particularly significant for a correct design of components manufactured with high power beam technologies and subjected to severe acceptance standards to ensure advanced performances during service life.

NASA Ames Research Center 60 MW Power Supply Modernization

NASA Technical Reports Server (NTRS)

Choy, Yuen Ching; Ilinets, Boris V.; Miller, Ted; Nagel, Kirsten (Technical Monitor)

2001-01-01

The NASA Ames Research Center 60 MW DC Power Supply was built in 1974 to provide controlled DC power for the Thermophysics Facility Arc Jet Laboratory. The Power Supply has gradually losing reliability due to outdated technology and component life limitation. NASA has decided to upgrade the existing rectifier modules with contemporary high-power electronics and control equipment. NASA plans to complete this project in 2001. This project includes a complete replacement of obsolete thyristor stacks in all six rectifier modules and rectifier bridge control system. High power water-cooled thyristors and freewheeling diodes will be used. The rating of each of the six modules will be 4000 A at 5500 V. The control firing angle signal will be sent from the Facility Control System to six modules via fiberoptic cable. The Power Supply control and monitoring system will include a Master PLC in the Facility building and a Slave PLC in each rectifier module. This system will also monitor each thyristor level in each stack and the auxiliary equipment.

Overview of space power electronic's technology under the CSTI High Capacity Power Program

NASA Technical Reports Server (NTRS)

Schwarze, Gene E.

1994-01-01

The Civilian Space Technology Initiative (CSTI) is a NASA Program targeted at the development of specific technologies in the areas of transportation, operations and science. Each of these three areas consists of major elements and one of the operation's elements is the High Capacity Power element. The goal of this element is to develop the technology base needed to meet the long duration, high capacity power requirements for future NASA initiatives. The High Capacity Power element is broken down into several subelements that includes energy conversion in the areas of the free piston Stirling power converter and thermoelectrics, thermal management, power management, system diagnostics, and environmental compatibility and system's lifetime. A recent overview of the CSTI High capacity Power element and a description of each of the program's subelements is given by Winter (1989). The goals of the Power Management subelement are twofold. The first is to develop, test, and demonstrate high temperature, radiation-resistant power and control components and circuits that will be needed in the Power Conditioning, Control and Transmission (PCCT) subsystem of a space nuclear power system. The results obtained under this goal will also be applicable to the instrumentation and control subsystem of a space nuclear reactor. These components and circuits must perform reliably for lifetimes of 7-10 years. The second goal is to develop analytical models for use in computer simulations of candidate PCCT subsystems. Circuits which will be required for a specific PCCT subsystem will be designed and built to demonstrate their performance and, also, to validate the analytical models and simulations. The tasks under the Power Management subelement will now be described in terms of objectives, approach and present status of work.

Fundamental Technology Development for Gas-Turbine Engine Health Management

NASA Technical Reports Server (NTRS)

Mercer, Carolyn R.; Simon, Donald L.; Hunter, Gary W.; Arnold, Steven M.; Reveley, Mary S.; Anderson, Lynn M.

2007-01-01

Integrated vehicle health management technologies promise to dramatically improve the safety of commercial aircraft by reducing system and component failures as causal and contributing factors in aircraft accidents. To realize this promise, fundamental technology development is needed to produce reliable health management components. These components include diagnostic and prognostic algorithms, physics-based and data-driven lifing and failure models, sensors, and a sensor infrastructure including wireless communications, power scavenging, and electronics. In addition, system assessment methods are needed to effectively prioritize development efforts. Development work is needed throughout the vehicle, but particular challenges are presented by the hot, rotating environment of the propulsion system. This presentation describes current work in the field of health management technologies for propulsion systems for commercial aviation.

Design of a Miniaturized Langmuir Plasma Probe for the QuadSat/PnP

NASA Astrophysics Data System (ADS)

Landavazo, M.; Jorgensen, A. M.; Del Barga, C.; Ferguson, D.; Guillette, D.; Huynh, A.; Klepper, J.; Kuker, J.; Lyke, J. C.; Marohn, B.; Mason, J.; Quiroga, J.; Ravindran, V.; Yelton, C.; Zagrai, A. N.; Zufelt, B.

2011-12-01

We have developed a miniaturized Langmuir plasma probe for measuring plasma density in low-earth orbit. Measuring plasma density in the upper ionosphere is important as a diagnostic for the rest of the ionosphere and as an input to space weather forecasting models. Developing miniaturized instrumentation allows easier deployment of a large number of small satellites for monitoring space weather. Our instrument was designed for the Swedish QuadSat/PnP, with the following constraints: A volume constraint of 5x5x1.25cm for the electronics enclosure, a mass budget 100 g, and a power budget of 0.5 W. We met the volume and mass constraints and where able to use less power than budgeted, only 0.25 W. We designed the probe for a bias range of +/-15V and current measurements in the 1 nA to 1 mA range (6 orders of magnitude). Necessary voltage of +/- 15 V and 3.3 V were generated on-board from a single 5 V supply. The electronics suite is based off carefully selected yet affordable commercial components that exhibit low noise, low leakage currents and low power consumption. Size constraints, low noise and low leakage requirements called for a carefully designed four layer PCB with a properly guarded current path using surface mount components on both sides. An ultra-low power microcontroller handles instrument functionality and is fully controllable over i2c using SPA-1 space plug and play. We elected for a probe launched deployed, which required careful design to survive launch vibrations while staying within the mass budget. The QuadSat/PnP has not been launched at the time of writing. We will present details of the instrument design and initial calibration data.

The Power Supply And Control Unit For The HEMP Thruster

NASA Astrophysics Data System (ADS)

Brag, Rafael; Lenz, Werner; Huther, Andreas; Herty, Frank

2011-10-01

In the recent years, Astrium GmbH started to develop electronics to control and supply Electric Propulsion systems or corresponding components. One of the developments is a Power Supply and Control Unit (PSCU) for the Thales Electron Devices development "High Efficiency Multistage Plasma Thruster" (HEMP- T). The PSCU is developed, manufactured and tested on the Astrium southern Germany site in Friedrichshafen. The first application is the SGEO Satellite (HISPASAT- 1), where the In-Orbit Demonstration (IOD) of the HEMP Thruster system will prove the success of the product. Astrium conducted several coupling tests during the PSCU development especially concentrated on *Thruster electrical I/F parameters *Neutralizer electrical I/F parameters *Flow Control I/F parameters Results of these tests were used to refine the specification and adapt the PSCU drivers and control algorithms. Furthermore, the tests results gave Thales and Astrium the possibility for a deep understanding of the interaction between the physics and the electronics. The paper presents an overview of the PSCU topology, key features, technical and development logic details as well as a view into the control capabilities of the PSCU.

Imaging crystal spectrometer for high-resolution x-ray measurements on electron beam ion traps and tokamaks

DOE PAGES

Beiersdorfer, P.; Magee, E. W.; Hell, N.; ...

2016-09-09

Here, we describe a crystal spectrometer implemented on the Livermore electron beam ion traps that employ two spherically bent quartz crystals and a cryogenically cooled back-illuminated charge-coupled device detector to measure x rays with a nominal resolving power of λ/Δλ ≥ 10 000. Its focusing properties allow us to record x rays either with the plane of dispersion perpendicular or parallel to the electron beam and, thus, to preferentially select one of the two linear x-ray polarization components. Moreover, by choice of dispersion plane and focussing conditions, we use the instrument either to image the distribution of the ions withinmore » the 2 cm long trap region, or to concentrate x rays of a given energy to a point on the detector, which optimizes the signal-to-noise ratio. We demonstrate the operation and utility of the new instrument by presenting spectra of Mo 34+, which prepares the instrument for use as a core impurity diagnostic on the NSTX-U spherical torus and other magnetic fusion devices that employ molybdenum as plasma facing components.« less

Electron energy balance and ionization in the channel of a stationary plasma thruster

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veselovzorov, A. N., E-mail: Veselovzorov-AN@nrcki.ru; Pogorelov, A. A.; Svirskiy, E. B.

2016-03-15

The paper presents results of numerical simulations of the electron dynamics in the field of the azimuthal and longitudinal waves excited in the channel of a stationary plasma thruster (SPT). The simulations are based on the experimentally determined wave characteristics. The simulation results show that the azimuthal wave displayed as ionization instability enhances electron transport along the thruster channel. It is established that the electron transport rate in the azimuthal wave increases as compared to the rate of diffusion caused by electron scattering from neutral atoms in proportion to the ratio between the times of electron− neutral collisions responsible formore » ionization and elastic electron scattering, respectively. An expression governing the plasma conductivity is derived with allowance for electron interaction with the azimuthal wave. The Hall parameter, the electron component of the discharge current, and the electron heating power in the thruster channel are calculated for two model SPTs operating with krypton and xenon. The simulation results agree well with the results of experimental studies of these two SPTs.« less

Recovery Act: Advanced Direct Methanol Fuel Cell for Mobile Computing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fletcher, James H.; Cox, Philip; Harrington, William J

2013-09-03

ABSTRACT Project Title: Recovery Act: Advanced Direct Methanol Fuel Cell for Mobile Computing PROJECT OBJECTIVE The objective of the project was to advance portable fuel cell system technology towards the commercial targets of power density, energy density and lifetime. These targets were laid out in the DOE’s R&D roadmap to develop an advanced direct methanol fuel cell power supply that meets commercial entry requirements. Such a power supply will enable mobile computers to operate non-stop, unplugged from the wall power outlet, by using the high energy density of methanol fuel contained in a replaceable fuel cartridge. Specifically this project focusedmore » on balance-of-plant component integration and miniaturization, as well as extensive component, subassembly and integrated system durability and validation testing. This design has resulted in a pre-production power supply design and a prototype that meet the rigorous demands of consumer electronic applications. PROJECT TASKS The proposed work plan was designed to meet the project objectives, which corresponded directly with the objectives outlined in the Funding Opportunity Announcement: To engineer the fuel cell balance-of-plant and packaging to meet the needs of consumer electronic systems, specifically at power levels required for mobile computing. UNF used existing balance-of-plant component technologies developed under its current US Army CERDEC project, as well as a previous DOE project completed by PolyFuel, to further refine them to both miniaturize and integrate their functionality to increase the system power density and energy density. Benefits of UNF’s novel passive water recycling MEA (membrane electrode assembly) and the simplified system architecture it enabled formed the foundation of the design approach. The package design was hardened to address orientation independence, shock, vibration, and environmental requirements. Fuel cartridge and fuel subsystems were improved to ensure effective fuel containment. PROJECT OVERVIEW The University of North Florida (UNF), with project partner the University of Florida, recently completed the Department of Energy (DOE) project entitled “Advanced Direct Methanol Fuel Cell for Mobile Computing”. The primary objective of the project was to advance portable fuel cell system technology towards the commercial targets as laid out in the DOE R&D roadmap by developing a 20-watt, direct methanol fuel cell (DMFC), portable power supply based on the UNF innovative “passive water recovery” MEA. Extensive component, sub-system, and system development and testing was undertaken to meet the rigorous demands of the consumer electronic application. Numerous brassboard (nonpackaged) systems were developed to optimize the integration process and facilitating control algorithm development. The culmination of the development effort was a fully-integrated, DMFC, power supply (referred to as DP4). The project goals were 40 W/kg for specific power, 55 W/l for power density, and 575 Whr/l for energy density. It should be noted that the specific power and power density were for the power section only, and did not include the hybrid battery. The energy density is based on three, 200 ml, fuel cartridges, and also did not include the hybrid battery. The results show that the DP4 system configured without the methanol concentration sensor exceeded all performance goals, achieving 41.5 W/kg for specific power, 55.3 W/l for power density, and 623 Whr/l for energy density. During the project, the DOE revised its technical targets, and the definition of many of these targets, for the portable power application. With this revision, specific power, power density, specific energy (Whr/kg), and energy density are based on the total system, including fuel tank, fuel, and hybridization battery. Fuel capacity is not defined, but the same value is required for all calculations. Test data showed that the DP4 exceeded all 2011 Technical Status values; for example, the DP4 energy density was 373 Whr/l versus the DOE 2011 status of 200 Whr/l. For the DOE 2013 Technical Goals, the operation time was increased from 10 hours to 14.3 hours. Under these conditions, the DP4 closely approached or surpassed the technical targets; for example, the DP4 achieved 468 Whr/l versus the goal of 500 Whr/l. Thus, UNF has successfully met the project goals. A fully-operational, 20-watt DMFC power supply was developed based on the UNF passive water recovery MEA. The power supply meets the project performance goals and advances portable power technology towards the commercialization targets set by the DOE.« less

Predicting the Noise of High Power Fluid Targets Using Computational Fluid Dynamics

NASA Astrophysics Data System (ADS)

Moore, Michael; Covrig Dusa, Silviu

The 2.5 kW liquid hydrogen (LH2) target used in the Qweak parity violation experiment is the highest power LH2 target in the world and the first to be designed with Computational Fluid Dynamics (CFD) at Jefferson Lab. The Qweak experiment determined the weak charge of the proton by measuring the parity-violating elastic scattering asymmetry of longitudinally polarized electrons from unpolarized liquid hydrogen at small momentum transfer (Q2 = 0 . 025 GeV2). This target satisfied the design goals of < 1 % luminosity reduction and < 5 % contribution to the total asymmetry width (the Qweak target achieved 2 % or 55ppm). State of the art time dependent CFD simulations are being developed to improve the predictions of target noise on the time scale of the electron beam helicity period. These predictions will be bench-marked with the Qweak target data. This work is an essential component in future designs of very high power low noise targets like MOLLER (5 kW, target noise asymmetry contribution < 25 ppm) and MESA (4.5 kW).

Wide bandgap BaSnO3 films with room temperature conductivity exceeding 104 S cm−1

PubMed Central

Prakash, Abhinav; Xu, Peng; Faghaninia, Alireza; Shukla, Sudhanshu; Ager, Joel W.; Lo, Cynthia S.; Jalan, Bharat

2017-01-01

Wide bandgap perovskite oxides with high room temperature conductivities and structural compatibility with a diverse family of organic/inorganic perovskite materials are of significant interest as transparent conductors and as active components in power electronics. Such materials must also possess high room temperature mobility to minimize power consumption and to enable high-frequency applications. Here, we report n-type BaSnO3 films grown using hybrid molecular beam epitaxy with room temperature conductivity exceeding 104 S cm−1. Significantly, these films show room temperature mobilities up to 120 cm2 V−1 s−1 even at carrier concentrations above 3 × 1020 cm−3 together with a wide bandgap (3 eV). We examine the mobility-limiting scattering mechanisms by calculating temperature-dependent mobility, and Seebeck coefficient using the Boltzmann transport framework and ab-initio calculations. These results place perovskite oxide semiconductors for the first time on par with the highly successful III–N system, thereby bringing all-transparent, high-power oxide electronics operating at room temperature a step closer to reality. PMID:28474675

Ultrafast high-power microwave window breakdown: nonlinear and postpulse effects.

PubMed

Chang, C; Verboncoeur, J; Guo, M N; Zhu, M; Song, W; Li, S; Chen, C H; Bai, X C; Xie, J L

2014-12-01

The time- and space-dependent optical emissions of nanosecond high-power microwave discharges near a dielectric-air interface have been observed by nanosecond-response four-framing intensified-charged-coupled device cameras. The experimental observations indicate that plasma developed more intensely at the dielectric-air interface than at the free-space region with a higher electric-field amplitude. A thin layer of intense light emission above the dielectric was observed after the microwave pulse. The mechanisms of the breakdown phenomena are analyzed by a three-dimensional electromagnetic-field modeling and a two-dimensional electromagnetic particle-in-cell simulation, revealing the formation of a space-charge microwave sheath near the dielectric surface, accelerated by the normal components of the microwave field, significantly enhancing the local-field amplitude and hence ionization near the dielectric surface. The nonlinear positive feedback of ionization, higher electron mobility, and ultraviolet-driven photoemission due to the elevated electron temperature are crucial for achieving the ultrafast discharge. Following the high-power microwave pulse, the sheath sustains a glow discharge until the sheath collapses.

Wide bandgap BaSnO 3 films with room temperature conductivity exceeding 10 4 S cm -1

DOE PAGES

Prakash, Abhinav; Xu, Peng; Faghaninia, Alireza; ...

2017-05-05

Wide bandgap perovskite oxides with high room temperature conductivities and structural compatibility with a diverse family of organic/inorganic perovskite materials are of sign ificant interest as transparent conductors and as active components in power electronics. Such materials must also possess high room temperature mobility to minimize power consumption and to enable high-frequency applications. Here, we report n-type BaSnO 3 films grown using hybrid molecular beam epitaxy with room temperature conductivity exceeding 10 4 S cm -1 . Significantly, these films show room temperature mobilities up to 120 cm 2 V -1 s -1 even at carrier concentrations abovemore » 3 × 10 20 cm -3 together with a wide bandgap (3 eV). We examine the mobility-limiting scattering mechanisms by calculating temperature-dependent mobility, and Seebeck coefficient using the Boltzmann transport framework and ab-initio calculations. These results place perovskite oxide semiconductors for the first time on par with the highly successful III-N system, thereby bringing all-transparent, high-power oxide electronics operating at room temperature a step closer to reality.« less

System design and operation of a 100 kilovolt, 2 kilohertz pulse modulator for plasma source ion implantation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reass, W.A.

1994-07-01

This paper describes the electrical design and operation of a high power modulator system implemented for the Los Alamos Plasma Source Ion Implantation (PSII) facility. To test the viability of the PSII process for various automotive components, the modulator must accept wide variations of load impedance. Components have varying area and composition which must be processed with different plasmas. Additionally, the load impedance may change by large factors during the typical 20 uS pulse, due to plasma displacement currents and sheath growth. As a preliminary design to test the system viability for automotive component implantation, suitable for a manufacturing environment,more » circuit topology must be able to directly scale to high power versions, for increased component through-put. We have chosen an evolutionary design approach with component families of characterized performance, which should Ion result in a reliable modulator system with component lifetimes. The modulator utilizes a pair of Litton L-3408 hollow beam amplifier tubes as switching elements in a ``hot-deck`` configuration. Internal to the main of planar triode hot deck, an additional pair decks, configured in a totem pole circuit, provide input drive to the L-3408 mod-anodes. The modulator can output over 2 amps average current (at 100 kV) with 1 kW of modanode drive. Diagnostic electronics monitor the load and stops pulses for 100 mS when a load arcs occur. This paper, in addition to providing detailed engineering design information, will provide operational characteristics and reliability data that direct the design to the higher power, mass production line capable modulators.« less

Space Environment Testing of Photovoltaic Array Systems at NASA's Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Schneider, Todd A.; Vaughn, Jason A.; Wright, Kenneth H., Jr.; Phillips, Brandon S.

2015-01-01

CubeSats, Communication Satellites, and Outer Planet Science Satellites all share one thing in common: Mission success depends on maintaining power in the harsh space environment. For a vast majority of satellites, spacecraft power is sourced by a photovoltaic (PV) array system. Built around PV cells, the array systems also include wiring, substrates, connectors, and protection diodes. Each of these components must function properly throughout the mission in order for power production to remain at nominal levels. Failure of even one component can lead to a crippling loss of power. To help ensure PV array systems do not suffer failures on-orbit due to the space environment, NASA's Marshall Space Flight Center (MSFC) has developed a wide ranging test and evaluation capability. Key elements of this capability include: Testing: a. Ultraviolet (UV) Exposure b. Charged Particle Radiation (Electron and Proton) c. Thermal Cycling d. Plasma and Beam Environments Evaluation: a. Electrostatic Discharge (ESD) Screening b. Optical Inspection and easurement c. PV Power Output including Large Area Pulsed Solar Simulator (LAPSS) measurements This paper will describe the elements of the space environment which particularly impact PV array systems. MSFC test capabilities will be described to show how the relevant space environments can be applied to PV array systems in the laboratory. A discussion of MSFC evaluation capabilities will also be provided. The sample evaluation capabilities offer test engineers a means to quantify the effects of the space environment on their PV array system or component. Finally, examples will be shown of the effects of the space environment on actual PV array materials tested at MSFC.

RXTE Observation of the Tycho Supernova Remnant

NASA Technical Reports Server (NTRS)

The, Lih-Sin

1998-01-01

SN1006 [4] and Cas A [1, 9] supernova remnants have been shown convincingly to have a hard X-ray power-law continuum. This continuum is thought to be the synchrotron radiation from accelerated electrons of approx. 100 TeV at the shock fronts. Our goal of AO2 RXTE observation is to detect the hard X-ray continuum and to determine the nature of the continuum from Tycho SNR. A detection of a power-law continuum from Tycho SNR can strongly argue for SNRs are the source of cosmic rays with the first order Fermi acceleration as the energizing process. We report the results of our AO2 RXTE 1 x 10(exp 5) sec observation of Tycho SNR. We detect two components of the X-ray spectrum from Tycho SNR both at better than 3 omega confidence. The best two component models are: bremsstrahlung (kT=2.67 +/- 0.13 keV) + bremsstrahlung (kT=7.07 +/- 2.21/1.72 keV) or bremsstrahlung (kT=2.36 +/- 0.21/0.57 keV) + power-law (gamma=2.58 +/- 0.12/0.09 ). This result is an improvement compaxed with the previous most sensitive X-ray measurements by Ginga which shows Tycho's observed X-ray continuum requires a two-component model to yield acceptable fits with the hard component parameters being highly uncertain. Our RXTE measurements constrain all parameter within 3o, ranges. However, we cannot yet distinguish between thermal and nonthermal models for the hard component. In the followings, we describe what we accomplished in the period covered by the grant proposal.

New trend in electron holography

NASA Astrophysics Data System (ADS)

Tanigaki, Toshiaki; Harada, Ken; Murakami, Yasukazu; Niitsu, Kodai; Akashi, Tetsuya; Takahashi, Yoshio; Sugawara, Akira; Shindo, Daisuke

2016-06-01

Electron holography using a coherent electron wave is a promising technique for high-resolution visualization of electromagnetic fields in and around objects. The capability of electron holography has been enhanced by the development of new technologies and has thus become an even more powerful tool for exploring scientific frontiers. This review introduces these technologies including split-illumination electron holography and vector-field electron tomography. Split-illumination electron holography, which uses separated coherent waves, overcomes the limits imposed by the lateral coherence requirement for electron waves in electron holography. Areas that are difficult to observe using conventional electron holography are now observable. Exemplified applications include observing a singular magnetic domain wall in electrical steel sheets, local magnetizations at anti-phase boundaries, and electrostatic potentials in metal-oxide-semiconductor field-effect transistors. Vector-field electron tomography can be used to visualize magnetic vectors in three dimensions. Two components of the vectors are reconstructed using dual-axis tomography, and the remaining one is calculated using div B   =  0. A high-voltage electron microscope can be used to achieve precise magnetic reconstruction. For example, magnetic vortices have been visualized using a 1 MV holography electron microscope.

Power-law X-ray and gamma-ray emission from relativistic thermal plasmas

NASA Technical Reports Server (NTRS)

Zdziarski, A. A.

1985-01-01

A common characteristic of cosmic sources is power-law X-ray emission. Extragalactic sources of this type include compact components of active galactic nuclei (AGN). The present study is concerned with a theoretical model of such sources, taking into account the assumption that the power-law spectra are produced by repeated Compton scatterings of soft photons by relativistic thermal electrons. This is one of several possible physical mechanisms leading to the formation of a power-law spectrum. Attention is given to the Comptonization of soft photon sources, the rates of pair processes, the solution of the pair equilibrium equation, and the constraints on a soft photon source and an energy source. It is concluded that the compactness parameters L/R of most of the cosmic sources observed to date lie below the maximum luminosity curves considered.

Detection of the high energy component of Jovian electrons at 1 AU with the PAMELA experiment.

NASA Astrophysics Data System (ADS)

Casolino, M.; PAMELA Collaboration

PAMELA is a satellite-borne experiment that will be launched in the first half of 2006 It will make long duration measurements of cosmic radiation over an extended energy range 80Mev to 200 GeV Specifically PAMELA will measure the cosmic-ray antiproton and positron spectra over the largest energy range ever achieved 80MeV - 190 GeV and will search for antinuclei with unprecedented sensitivity Furthermore it will measure the light nuclear component of cosmic rays and investigate phenomena connected with solar and earth physics The apparatus consists of a time of flight system a magnetic spectrometer an electromagnetic imaging calorimeter a shower tail catcher scintillator a neutron detector and an anticoincidence system The Jovian magnetosphere is a powerful accelerator of electrons to several tens of MeV as observed at first by Pioneer 10 spacecraft 1973 The propagation of Jovian electrons to Earth is affected by modulation due to Corotating Interaction Regions CIR Their flux at Earth is moreover modulated because every 13 months Earth and Jupiter are aligned along the average direction of the Parker spiral of the Interplanetary Magnetic Field For its characteristics PAMELA will be able to measure the high energy tail of the Jovian electrons in the energy range from 50 MeV up to 130 MeV With long term observation it will also be possible to detect the Jovian component reaccelated at the solar wind termination shock from the galactic flux

Modular electron-transport chains from eukaryotic organelles function to support nitrogenase activity.

PubMed

Yang, Jianguo; Xie, Xiaqing; Yang, Mingxuan; Dixon, Ray; Wang, Yi-Ping

2017-03-21

A large number of genes are necessary for the biosynthesis and activity of the enzyme nitrogenase to carry out the process of biological nitrogen fixation (BNF), which requires large amounts of ATP and reducing power. The multiplicity of the genes involved, the oxygen sensitivity of nitrogenase, plus the demand for energy and reducing power, are thought to be major obstacles to engineering BNF into cereal crops. Genes required for nitrogen fixation can be considered as three functional modules encoding electron-transport components (ETCs), proteins required for metal cluster biosynthesis, and the "core" nitrogenase apoenzyme, respectively. Among these modules, the ETC is important for the supply of reducing power. In this work, we have used Escherichia coli as a chassis to study the compatibility between molybdenum and the iron-only nitrogenases with ETC modules from target plant organelles, including chloroplasts, root plastids, and mitochondria. We have replaced an ETC module present in diazotrophic bacteria with genes encoding ferredoxin-NADPH oxidoreductases (FNRs) and their cognate ferredoxin counterparts from plant organelles. We observe that the FNR-ferredoxin module from chloroplasts and root plastids can support the activities of both types of nitrogenase. In contrast, an analogous ETC module from mitochondria could not function in electron transfer to nitrogenase. However, this incompatibility could be overcome with hybrid modules comprising mitochondrial NADPH-dependent adrenodoxin oxidoreductase and the Anabaena ferredoxins FdxH or FdxB. We pinpoint endogenous ETCs from plant organelles as power supplies to support nitrogenase for future engineering of diazotrophy in cereal crops.

Ethanol concentration in 56 refillable electronic cigarettes liquid formulations determined by headspace gas chromatography with flame ionization detector (HS-GC-FID).

PubMed

Poklis, Justin L; Wolf, Carl E; Peace, Michelle R

2017-10-01

Personal battery-powered vaporizers or electronic cigarettes were developed as an alternative to traditional cigarettes. The modern electronic cigarettes were patented in 2004 by Hon Lik in China. In May 2016, the US Food and Drug Administration (FDA) imposed regulatory statutes on e-cigarettes and their liquid formulations (e-liquids); prior to that, they were unregulated. E-liquids are typically composed of propylene glycol and/or glycerin, flavouring component(s), and active ingredient(s), such as nicotine. Fifty-six commercially available e-liquids, purchased from various sources, contained a variety of flavours and active ingredients. A headspace gas chromatography with flame ionization detector (HS-GC-FID) method was used to analyze these e-liquids for volatiles content. Only one of the e-liquids listed ethanol as a component. The chromatographic separation of volatiles was performed on a Restek BAC-1 column. A linear calibration was generated for ethanol with limits of detection and quantification (LOD/LOQ) of 0.05 mg/mL. Ethanol concentrations in the 56 e-liquids ranged from none detected to 206 mg/mL. The ethanol determined in these products may have been used in flavourants or a solvent; the reason for inclusion cannot be fully ascertained. The implications of vaporizing ethanol as an e-liquid component are unknown. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Mechanically Flexible and High-Performance CMOS Logic Circuits.

PubMed

Honda, Wataru; Arie, Takayuki; Akita, Seiji; Takei, Kuniharu

2015-10-13

Low-power flexible logic circuits are key components required by the next generation of flexible electronic devices. For stable device operation, such components require a high degree of mechanical flexibility and reliability. Here, the mechanical properties of low-power flexible complementary metal-oxide-semiconductor (CMOS) logic circuits including inverter, NAND, and NOR are investigated. To fabricate CMOS circuits on flexible polyimide substrates, carbon nanotube (CNT) network films are used for p-type transistors, whereas amorphous InGaZnO films are used for the n-type transistors. The power consumption and voltage gain of CMOS inverters are <500 pW/mm at Vin = 0 V (<7.5 nW/mm at Vin = 5 V) and >45, respectively. Importantly, bending of the substrate is not found to cause significant changes in the device characteristics. This is also observed to be the case for more complex flexible NAND and NOR logic circuits for bending states with a curvature radius of 2.6 mm. The mechanical stability of these CMOS logic circuits makes them ideal candidates for use in flexible integrated devices.

Mechanically Flexible and High-Performance CMOS Logic Circuits

PubMed Central

Honda, Wataru; Arie, Takayuki; Akita, Seiji; Takei, Kuniharu

2015-01-01

Low-power flexible logic circuits are key components required by the next generation of flexible electronic devices. For stable device operation, such components require a high degree of mechanical flexibility and reliability. Here, the mechanical properties of low-power flexible complementary metal–oxide–semiconductor (CMOS) logic circuits including inverter, NAND, and NOR are investigated. To fabricate CMOS circuits on flexible polyimide substrates, carbon nanotube (CNT) network films are used for p-type transistors, whereas amorphous InGaZnO films are used for the n-type transistors. The power consumption and voltage gain of CMOS inverters are <500 pW/mm at Vin = 0 V (<7.5 nW/mm at Vin = 5 V) and >45, respectively. Importantly, bending of the substrate is not found to cause significant changes in the device characteristics. This is also observed to be the case for more complex flexible NAND and NOR logic circuits for bending states with a curvature radius of 2.6 mm. The mechanical stability of these CMOS logic circuits makes them ideal candidates for use in flexible integrated devices. PMID:26459882

Detection of a Spectral Break in the Extra Hard Component of GRB 090926A

NASA Astrophysics Data System (ADS)

Ackermann, M.; Ajello, M.; Asano, K.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bhat, P. N.; Bissaldi, E.; Blandford, R. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brez, A.; Briggs, M. S.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Carrigan, S.; Casandjian, J. M.; Cecchi, C.; Çelik, Ö.; Chaplin, V.; Charles, E.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Connaughton, V.; Conrad, J.; Cutini, S.; Dermer, C. D.; de Angelis, A.; de Palma, F.; Dingus, B. L.; Silva, E. do Couto e.; Drell, P. S.; Dubois, R.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Frailis, M.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Goldstein, A.; Granot, J.; Greiner, J.; Grenier, I. A.; Grove, J. E.; Guiriec, S.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashi, K.; Hayashida, M.; Hays, E.; Horan, D.; Hughes, R. E.; Itoh, R.; Jóhannesson, G.; Johnson, A. S.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kippen, R. M.; Knödlseder, J.; Kocevski, D.; Kouveliotou, C.; Kuss, M.; Lande, J.; Latronico, L.; Lee, S.-H.; Llena Garde, M.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Makeev, A.; Mazziotta, M. N.; McBreen, S.; McEnery, J. E.; McGlynn, S.; Meegan, C.; Mehault, J.; Mészáros, P.; Michelson, P. F.; Mizuno, T.; Monte, C.; Monzani, M. E.; Moretti, E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakajima, H.; Nakamori, T.; Naumann-Godo, M.; Nishino, S.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohno, M.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paciesas, W. S.; Paneque, D.; Panetta, J. H.; Parent, D.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Petrosian, V.; Piron, F.; Porter, T. A.; Preece, R.; Racusin, J. L.; Rainò, S.; Rando, R.; Rau, A.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Reposeur, T.; Reyes, L. C.; Ripken, J.; Ritz, S.; Roth, M.; Ryde, F.; Sadrozinski, H. F.-W.; Sander, A.; Scargle, J. D.; Schalk, T. L.; Sgrò, C.; Siskind, E. J.; Smith, P. D.; Spandre, G.; Spinelli, P.; Stamatikos, M.; Stecker, F. W.; Strickman, M. S.; Suson, D. J.; Tajima, H.; Takahashi, H.; Tanaka, T.; Tanaka, Y.; Thayer, J. B.; Thayer, J. G.; Tibaldo, L.; Tierney, D.; Toma, K.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Uehara, T.; Usher, T. L.; Vandenbroucke, J.; van der Horst, A. J.; Vasileiou, V.; Vilchez, N.; Vitale, V.; von Kienlin, A.; Waite, A. P.; Wang, P.; Wilson-Hodge, C.; Winer, B. L.; Wood, K. S.; Wu, X. F.; Yamazaki, R.; Yang, Z.; Ylinen, T.; Ziegler, M.

2011-03-01

We report on the observation of the bright, long gamma-ray burst, GRB 090926A, by the Gamma-ray Burst Monitor and Large Area Telescope (LAT) instruments on board the Fermi Gamma-ray Space Telescope. GRB 090926A shares several features with other bright LAT bursts. In particular, it clearly shows a short spike in the light curve that is present in all detectors that see the burst, and this in turn suggests that there is a common region of emission across the entire Fermi energy range. In addition, while a separate high-energy power-law component has already been observed in other gamma-ray bursts, here we report for the first time the detection with good significance of a high-energy spectral break (or cutoff) in this power-law component around 1.4 GeV in the time-integrated spectrum. If the spectral break is caused by opacity to electron-positron pair production within the source, then this observation allows us to compute the bulk Lorentz factor for the outflow, rather than a lower limit.

The G_E/G_M-ratio of the proton by recoil polarization measurement in e+parrow e'+p

NASA Astrophysics Data System (ADS)

Punjabi, Vina; Jones, Mark; Perdrisat, Charles F.; Quemener, Gilles

1998-10-01

The recently commissioned Hall A high resolution spectrometers (HRS) and the focal plane polarimeter (FPP) were used to obtain the ratio of the electric and magnetic form factors of the proton, G_E/G_M. This form factor ratio is proportional to the measured ratio of the transverse, P_t, to longitudinal, P_l, components of the recoiling proton polarization. The method takes advantage of the precession of the proton magnetic moment in the hadron HRS, which rotates the longitudinal polarization component into the plane of the FPP analyzer; this allows simultaneous measurement of both components of the polarization. The ratio P_t/P_l is independent of both the electron beam polarization and the polarimeter analyzing power. Most of the data were obtained with polarized beams of 100 μ A with polarization of ~ 0.39 incident on the 15 cm cell of the high power LH2 target. We will report the results for G_E/GM at several values of Q^2 between 0.5 and 3.5 GeV^2.

Detection of a spectral break in the extra hard component of GRB 090926A

DOE PAGES

Ackermann, M.; Ajello, M.; Asano, K.; ...

2011-02-16

Here, we report on the observation of the bright, long gamma-ray burst, GRB 090926A, by the Gamma-ray Burst Monitor and Large Area Telescope (LAT) instruments on board the Fermi Gamma-ray Space Telescope. GRB 090926A shares several features with other bright LAT bursts. In particular, it clearly shows a short spike in the light curve that is present in all detectors that see the burst, and this in turn suggests that there is a common region of emission across the entire Fermi energy range. In addition, while a separate high-energy power-law component has already been observed in other gamma-ray bursts, heremore » we report for the first time the detection with good significance of a high-energy spectral break (or cutoff) in this power-law component around 1.4 GeV in the time-integrated spectrum. If the spectral break is caused by opacity to electron-positron pair production within the source, then this observation allows us to compute the bulk Lorentz factor for the outflow, rather than a lower limit.« less

Evolution of the 1-mlb mercury ion thruster subsystem

NASA Technical Reports Server (NTRS)

Kerslake, W. R.; Banks, B. A.

1978-01-01

The developmental history, performance, and major lifetests of each component of the present 1-mlb (4.5 mN) thruster system are traced over the past 10 years. The 1-mlb thruster subsystem consists of an 8 cm diameter ion thruster mounted on 2 axis gimbals, a mercury propellant tank, a power electronics unit, a controller/digital interface unit, and necessary electrical harnesses plus propellant tankage and feed lines.

Experimental Studies of Ageing in Electrolytic Capacitors

DTIC Science & Technology

2010-10-01

mechanisms of electronic components critical avionics systems such as the GPS and INAV are of critical importance. Electrolytic capac- itors and...the Inertial Navigation ( INAV ) system, causing the aircraft to fly off course. In this paper, we present the details of our ageing methodology along...directed towards DC-DC convert- ers in Avionics systems. In these systems the power supply drives a Global Positioning System (GPS) and INAV unit, and

An Electronic Patch for wearable health monitoring by reflectance pulse oximetry.

PubMed

Haahr, Rasmus G; Duun, Sune B; Toft, Mette H; Belhage, Bo; Larsen, Jan; Birkelund, Karen; Thomsen, Erik V

2012-02-01

We report the development of an Electronic Patch for wearable health monitoring. The Electronic Patch is a new health monitoring system incorporating biomedical sensors, microelectronics, radio frequency (RF) communication, and a battery embedded in a 3-dimensional hydrocolloid polymer. In this paper the Electronic Patch is demonstrated with a new optical biomedical sensor for reflectance pulse oximetry so that the Electronic Patch in this case can measure the pulse and the oxygen saturation. The reflectance pulse oximetry solution is based on a recently developed annular backside silicon photodiode to enable low power consumption by the light emitting components. The Electronic Patch has a disposable part of soft adhesive hydrocolloid polymer and a reusable part of hard polylaurinlactam. The disposable part contains the battery. The reusable part contains the reflectance pulse oximetry sensor and microelectronics. The reusable part is 'clicked' into the disposable part when the patch is prepared for use. The patch has a size of 88 mm by 60 mm and a thickness of 5 mm.

Electronic Power Conditioner for Ku-band Travelling Wave Tube

NASA Astrophysics Data System (ADS)

Kowstubha, Palle; Krishnaveni, K.; Ramesh Reddy, K.

2017-04-01

A highly sophisticated regulated power supply is known as electronic power conditioner (EPC) is required to energise travelling wave tubes (TWTs), which are used as RF signal amplifiers in satellite payloads. The assembly consisting of TWT and EPC together is known as travelling wave tube amplifier (TWTA). EPC is used to provide isolated and conditioned voltage rails with tight regulation to various electrodes of TWT and makes its RF performance independent of solar bus variations which are caused due to varying conditions of eclipse and sunlit. The payload mass and their power consumption is mainly due to the existence of TWTAs that represent about 35 % of total mass and about 70-90 % (based on the type of satellite application) of overall dc power consumption. This situation ensures a continuous improvement in the design of TWTAs and their associated EPCs to realize more efficient and light products. Critical technologies involved in EPCs are design and configuration, closed loop regulation, component and material selection, energy limiting of high voltage (HV) outputs and potting of HV card etc. This work addresses some of these critical technologies evolved in realizing and testing the state of art of EPC and it focuses on the design of HV supply with a HV and high power capability, up to 6 kV and 170 WRF, respectively required for a space TWTA. Finally, an experimental prototype of EPC with a dc power of 320 W provides different voltages required by Ku-band TWT in open loop configuration.

Electron beam diagnostic for profiling high power beams

DOEpatents

Elmer, John W [Danville, CA; Palmer, Todd A [Livermore, CA; Teruya, Alan T [Livermore, CA

2008-03-25

A system for characterizing high power electron beams at power levels of 10 kW and above is described. This system is comprised of a slit disk assembly having a multitude of radial slits, a conducting disk with the same number of radial slits located below the slit disk assembly, a Faraday cup assembly located below the conducting disk, and a start-stop target located proximate the slit disk assembly. In order to keep the system from over-heating during use, a heat sink is placed in close proximity to the components discussed above, and an active cooling system, using water, for example, can be integrated into the heat sink. During use, the high power beam is initially directed onto a start-stop target and after reaching its full power is translated around the slit disk assembly, wherein the beam enters the radial slits and the conducting disk radial slits and is detected at the Faraday cup assembly. A trigger probe assembly can also be integrated into the system in order to aid in the determination of the proper orientation of the beam during reconstruction. After passing over each of the slits, the beam is then rapidly translated back to the start-stop target to minimize the amount of time that the high power beam comes in contact with the slit disk assembly. The data obtained by the system is then transferred into a computer system, where a computer tomography algorithm is used to reconstruct the power density distribution of the beam.

Trends and problems in development of the power plants electrical part

NASA Astrophysics Data System (ADS)

Gusev, Yu. P.

2015-03-01

The article discusses some problems relating to development of the electrical part of modern nuclear and thermal power plants, which are stemming from the use of new process and electrical equipment, such as gas turbine units, power converters, and intellectual microprocessor devices in relay protection and automated control systems. It is pointed out that the failure rates of electrical equipment at Russian and foreign power plants tend to increase. The ongoing power plant technical refitting and innovative development processes generate the need to significantly widen the scope of research works on the electrical part of power plants and rendering scientific support to works on putting in use innovative equipment. It is indicated that one of main factors causing the growth of electrical equipment failures is that some of components of this equipment have insufficiently compatible dynamic characteristics. This, in turn may be due to lack or obsolescence of regulatory documents specifying the requirements for design solutions and operation of electric power equipment that incorporates electronic and microprocessor control and protection devices. It is proposed to restore the system of developing new and updating existing departmental regulatory technical documents that existed in the 1970s, one of the fundamental principles of which was placing long-term responsibility on higher schools and leading design institutions for rendering scientific-technical support to innovative development of components and systems forming the electrical part of power plants. This will make it possible to achieve lower failure rates of electrical equipment and to steadily improve the competitiveness of the Russian electric power industry and energy efficiency of generating companies.

Widely tunable opto-electronic oscillator

NASA Astrophysics Data System (ADS)

Maxin, J.; Pillet, G.; Morvan, L.; Dolfi, D.

2012-03-01

We present here a widely tunable opto-electronic oscillator (OEO) based on an Er,Yb:glass Dual Frequency Laser (DFL) at 1.53 μm. The beatnote is stabilized with an optical fiber delay line. Compared to classical optoelectronic oscillators, this architecture does not need RF filter and offers a wide tunability. We measured a reduction of 67 dB of the phase noise power spectral density (PSD) at 10 Hz of the carrier optical fiber leading to a level of -27 dBc/Hz with only 100 m optical fiber. Moreover, the scheme offers a microwave signal tunability from 2.5 to 5.5 GHz limited by the RF components.

A Bulk Comptonization Model for the Prompt GRB Emission and its Relation to the Fermi GRB Spectra

NASA Technical Reports Server (NTRS)

Kazanas, Demosthenes

2010-01-01

We present a model in which the GRB prompt emission at E E(sub peak) is due to bulk Comptonization by the relativistic blast wave motion of either its own synchrotron photons of ambient photons of the stellar configuration that gave birth to the GRB. The bulk Comptonization process then induces the production of relativistic electrons of Lorentz factor equal to that of the blast wave through interactions with its ambient protons. The inverse compton emission of these electrons produces a power law component that extends to multi GeV energies in good agreement with the LAT GRB observations.

Power Electronics Thermal Management | Transportation Research | NREL

Science.gov Websites

Power Electronics Thermal Management Power Electronics Thermal Management A photo of water boiling in liquid cooling lab equipment. Power electronics thermal management research aims to help lower the investigates and develops thermal management strategies for power electronics systems that use wide-bandgap

Design and characterization of an irradiation facility with real-time monitoring

NASA Astrophysics Data System (ADS)

Braisted, Jonathan David

Radiation causes performance degradation in electronics by inducing atomic displacements and ionizations. While radiation hardened components are available, non-radiation hardened electronics can be preferable because they are generally more compact, require less power, and less expensive than radiation tolerant equivalents. It is therefore important to characterize the performance of electronics, both hardened and non-hardened, to prevent costly system or mission failures. Radiation effects tests for electronics generally involve a handful of step irradiations, leading to poorly-resolved data. Step irradiations also introduce uncertainties in electrical measurements due to temperature annealing effects. This effect may be intensified if the time between exposure and measurement is significant. Induced activity in test samples also complicates data collection of step irradiated test samples. The University of Texas at Austin operates a 1.1 MW Mark II TRIGA research reactor. An in-core irradiation facility for radiation effects testing with a real-time monitoring capability has been designed for the UT TRIGA reactor. The facility is larger than any currently available non-central location in a TRIGA, supporting testing of larger electronic components as well as other in-core irradiation applications requiring significant volume such as isotope production or neutron transmutation doping of silicon. This dissertation describes the design and testing of the large in-core irradiation facility and the experimental campaign developed to test the real-time monitoring capability. This irradiation campaign was performed to test the real-time monitoring capability at various reactor power levels. The device chosen for characterization was the 4N25 general-purpose optocoupler. The current transfer ratio, which is an important electrical parameter for optocouplers, was calculated as a function of neutron fluence and gamma dose from the real-time voltage measurements. The resultant radiation effects data was seen to be repeatable and exceptionally finely-resolved. Therefore, the capability at UT TRIGA has been proven competitive with world-class effects characterization facilities.

First-principles modeling of the thermoelectric properties of SrTiO3/SrRuO3 superlattices

NASA Astrophysics Data System (ADS)

García-Fernández, Pablo; Verissimo-Alves, Marcos; Bilc, Daniel I.; Ghosez, Philippe; Junquera, Javier

2012-08-01

Using a combination of first-principles simulations, based on density functional theory and Boltzmann's semiclassical theory, we have calculated the transport and thermoelectric properties of the half-metallic two-dimensional electron gas confined in single SrRuO3 layers of SrTiO3/SrRuO3 periodic superlattices. Close to the Fermi energy, we find that the semiconducting majority-spin channel displays a very large in-plane component of the Seebeck tensor at room temperature, S˜ 1500 μV/K, and the minority-spin channel shows good in-plane conductivity, σ=2.5 (mΩ cm)-1. However, we find that the total power factor and thermoelectric figure of merit for reduced doping is too small for practical applications. Our results support that the confinement of the electronic motion is not the only thing that matters to describe the main features of the transport and thermoelectric properties with respect the chemical doping, but the shape of the electronic density of states, which in our case departs from the free-electron behavior, is also important. The evolution of the electronic structure, electrical conductivity, Seebeck coefficient, and power factor as a function of the chemical potential is explained by a simplified tight-binding model. We find that the electron gas in our system is composed by a pair of one-dimensional electron gases orthogonal to each other. This reflects the fact the physical dimensionality of the electronic system (1D) can be even smaller than that of the spacial confinement of the carriers (2D).

Associative Pattern Recognition In Analog VLSI Circuits

NASA Technical Reports Server (NTRS)

Tawel, Raoul

1995-01-01

Winner-take-all circuit selects best-match stored pattern. Prototype cascadable very-large-scale integrated (VLSI) circuit chips built and tested to demonstrate concept of electronic associative pattern recognition. Based on low-power, sub-threshold analog complementary oxide/semiconductor (CMOS) VLSI circuitry, each chip can store 128 sets (vectors) of 16 analog values (vector components), vectors representing known patterns as diverse as spectra, histograms, graphs, or brightnesses of pixels in images. Chips exploit parallel nature of vector quantization architecture to implement highly parallel processing in relatively simple computational cells. Through collective action, cells classify input pattern in fraction of microsecond while consuming power of few microwatts.

Power Amplifier Module with 734-mW Continuous Wave Output Power

NASA Technical Reports Server (NTRS)

Fung, King Man; Samoska, Lorene A.; Kangaslahti, Pekka P.; Lamgrigtsen, Bjorn H.; Goldsmith, Paul F.; Lin, Robert H.; Soria, Mary M.; Cooperrider, Joelle T.; Micovic, Moroslav; Kurdoghlian, Ara

2010-01-01

Research findings were reported from an investigation of new gallium nitride (GaN) monolithic millimeter-wave integrated circuit (MMIC) power amplifiers (PAs) targeting the highest output power and the highest efficiency for class-A operation in W-band (75-110 GHz). W-band PAs are a major component of many frequency multiplied submillimeter-wave LO signal sources. For spectrometer arrays, substantial W-band power is required due to the passive lossy frequency multipliers-to generate higher frequency signals in nonlinear Schottky diode-based LO sources. By advancing PA technology, the LO system performance can be increased with possible cost reductions compared to current GaAs PAs. High-power, high-efficiency GaN PAs are cross-cutting and can enable more efficient local oscillator distribution systems for new astrophysics and planetary receivers and heterodyne array instruments. It can also allow for a new, electronically scannable solid-state array technology for future Earth science radar instruments and communications platforms.

High-efficiency L-band T/R Module: Development Results

NASA Technical Reports Server (NTRS)

Edelstein, Wendy N.; Andricos, Constantine; Wang, Feiyu; Rutled, David B.

2005-01-01

Future interferometric synthetic aperture radar (InSAR) systems require electronically scanned phased-array antennas, where the transmit/receive (T/R) module is a key component. The T/R module efficiency is a critical figure of merit and has direct implications on the power dissipation and power generation requirements of the system. Significant improvements in the efficiency of the T/R module will make SAR missions more feasible and affordable. The results of two high-efficiency T/R modules are presented, each based on different power amplifier technologies. One module uses a 30W GaAs Class-AlB power amplifier and the second module uses a 70W LD-MOS Class-ElF power amplifier, where both modules use a common low power section. Each module operates over an 80MHz bandwidth at L-band (1.2GHz) with an overall module efficiency greater than 58%. We will present the results of these two T/R modules that have been designed, built and tested.

The Space Technology 5 Power System Design

NASA Technical Reports Server (NTRS)

Stewart, Karen D.; Hernandez-Pellerano, Amri I.

2005-01-01

The Space Technology 5 (ST5) mission is a NASA New Millennium Program (NMP) project that was developed to validate new technologies for future missions and to demonstrate the feasibility of building and launching multiple, miniature spacecraft that can operate as science probes, collecting research quality measurements. The three satellites in the ST5 constellation will be launched into a sun synchronous LEO (Low Earth Orbit) in early 2006. ST5 fits in the 25 kilogram and 24 Watt class of miniature but fully capable spacecraft. The power system design features the use of new technology components and a low voltage power bus. In order to hold the mass and volume low and to qualify new technologies for future use in space, high efficiency triple junction solar cells and a lithium ion battery were baselined into the design. The Power System Electronics (PSE) was designed for a high radiation environment and uses hybrid microcircuits for power switching and over current protection. The ST5 power system architecture and technologies will be presented.

Nanocomposites in Multifuntional Structures for Spacecraft Platforms

NASA Astrophysics Data System (ADS)

Marcos, J.; Mendizabal, M.; Elizetxea, C.; Florez, S.; Atxaga, G.; Del Olmo, E.

2012-07-01

The integration of functionalities as electrical, thermal, power or radiation shielding inside carrier electronic boxes, solar panels or platform structures allows reducing weight, volume, and harness for spacecraft. The multifunctional structures represent an advanced design approach for space components and subsystems. The development of such multifunctional structures aims the re-engineering traditional metallic structures by composites in space, which request to provide specific solutions for thermal conductivity, EMI-EMC, radiation shielding and integration. The use of nanomaterials as CNF and nano-adds to reinforce composite structures allows obtaining local solutions for improving electrical conductivity, thermal conductivity and radiation shielding. The paper summarises the results obtained in of three investigations conducted by Tecnalia based on carbon nanofillers for improving electro-thermal characteristics of spacecraft platform, electronic substrates and electronics boxes respectively.

Observation of magnetic fluctuations and rapid density decay of magnetospheric plasma in Ring Trap 1

NASA Astrophysics Data System (ADS)

Saitoh, H.; Yoshida, Z.; Morikawa, J.; Yano, Y.; Mikami, H.; Kasaoka, N.; Sakamoto, W.

2012-06-01

The Ring Trap 1 device, a magnetospheric configuration generated by a levitated dipole field magnet, has created high-β (local β ˜ 70%) plasma by using electron cyclotron resonance heating (ECH). When a large population of energetic electrons is generated at low neutral gas pressure operation, high frequency magnetic fluctuations are observed. When the fluctuations are strongly excited, rapid loss of plasma was simultaneously observed especially in a quiet decay phase after the ECH microwave power is turned off. Although the plasma is confined in a strongly inhomogeneous dipole field configuration, the frequency spectra of the fluctuations have sharp frequency peaks, implying spatially localized sources of the fluctuations. The fluctuations are stabilized by decreasing the hot electron component below approximately 40%, realizing stable high-β confinement.

Microcomputer control of an electronically commutated dc motor

NASA Astrophysics Data System (ADS)

El-Sharkawi, M. A.; Coleman, J. S.; Mehdi, I. S.; Sommer, D. L.

A microcomputer control system for an electronically commutated dc motor (ECM) has been designed, built and tested. A 3-hp, 270-volt, samarium-cobalt brushless dc motor is controlled by an Intel 8086-based microcomputer. The main functions of the microcomputer are to control the speed of the motor, to provide forward or reverse rotation, to brake, and to protect the motor and its power electronic switching circuits from overcurrents. The necessary interface circuits were designed and built, and the system components have been integrated and tested. It is shown that the proposed ECM system with the microcomputer control operate the motor reliably over a wide range of speeds. The purpose of this effort is to develop the motorcontroller for driving electromechanical actuators for flight control and other aircraft applications.

High-Energy Emission From Millisecond Pulsars

NASA Technical Reports Server (NTRS)

Harding, Alice K.; Usov, Vladimir V.; Muslimov, Alex G.

2004-01-01

The X-ray and gamma-ray spectrum of rotation-powered millisecond pulsars is investigated in a model for acceleration and pair cascades on open field lines above the polar caps. Although these pulsars have low surface magnetic fields, their short periods allow them to have large magnetospheric potential drops, but the majority do not produce sufficient pairs to completely screen the accelerating electric field. In these sources, the primary and secondary electrons continue to accelerate to high altitude and their Lorentz factors are limited by curvature and synchrotron radiation reaction. The accelerating particles maintain high Lorentz factors and undergo cyclotron resonant absorption of radio emission, that produces and maintains a large pitch angle, resulting in a strong synchrotron component. The resulting spectra consist of several distinct components: curvature radiation from primary electrons dominating from 1 - 100 GeV, synchrotron radiation from primary and secondary electrons dominating up to about 100 MeV, and much weaker inverse-Compton radiation from primary electrons a t 0.1 - 1 TeV. We find that the relative size of these components depends on pulsar period, period derivative, and neutron star mass and radius with the level of the synchrotron component also depending sensitively on the radio emission properties. This model is successful in describing the observed X-ray and gamma-ray spectrum of PSR J0218+4232 as synchrotron radiation, peaking around 100 MeV and extending up to a turnover around several GeV. The predicted curvature radiation components from a number of millisecond pulsars, as well as the collective emission from the millisecond pulsars in globular clusters, should be detectable with AGILE and GLAST. We also discuss a hidden population of X-ray-quiet and radio-quiet millisecond pulsars which have evolved below the pair death line, some of which may be detectable by telescopes sensitive above 1 GeV. Subject headings: pulsars: general - radiation mechanisms: nonthermal - stars: neutron - gamma rays: theory

Optical characteristics and parameters of gas-discharge plasma in a mixture of mercury dibromide vapor with neon

NASA Astrophysics Data System (ADS)

Malinina, A. A.; Malinin, A. N.

2013-12-01

Results are presented from studies of the optical characteristics and parameters of plasma of a dielectric barrier discharge in a mixture of mercury dibromide vapor with neon—the working medium of a non-coaxial exciplex gas-discharge emitter. The electron energy distribution function, the transport characteristics, the specific power losses for electron processes, the electron density and temperature, and the rate constants for the processes of elastic and inelastic electron scattering by the working mixture components are determined as functions of the reduced electric field. The rate constant of the process leading to the formation of exciplex mercury monobromide molecules is found to be 1.6 × 10-14 m3/s for a reduced electric field of E/ N = 15 Td, at which the maximum emission intensity in the blue-green spectral region (λmax = 502 nm) was observed in this experiment.

The new front-end electronics for the ATLAS Tile Calorimeter Phase 2 Upgrade

NASA Astrophysics Data System (ADS)

Gomes, A.

2016-02-01

We present the plans, design, and performance results to date for the new front-end electronics being developed for the Phase 2 Upgrade of the ATLAS Tile Calorimeter. The front-end electronics will be replaced to address the increased luminosity at the HL-LHC around 2025, as well as to upgrade to faster, more modern components with higher radiation tolerance. The new electronics will operate dead-timelessly, pushing full data sets from each beam crossing to the data acquisition system that resides off-detector. The new on-detector electronics contains five main parts: the front-end boards that connect directly to the photomultiplier tubes; the Main Boards that digitize the data; the Daughter Boards that collect the data streams and contain the high speed optical communication links for writing data to the data acquisition system; a programmable high voltage control system; and a new low voltage power supply. There are different options for implementing these subcomponents, which will be described. The new system contains new features that in the current version include power system redundancy, data collection redundancy, data transmission redundancy with 2 QSFP optical transceivers and Kintex-7 FPGAs with firmware enhanced scheme for single event upset mitigation. To date, we have built a Demonstrator—a fully functional prototype of the new system. Performance results and plans are presented.

Cooling system for electronic components

DOEpatents

Anderl, William James; Colgan, Evan George; Gerken, James Dorance; Marroquin, Christopher Michael; Tian, Shurong

2015-12-15

Embodiments of the present invention provide for non interruptive fluid cooling of an electronic enclosure. One or more electronic component packages may be removable from a circuit card having a fluid flow system. When installed, the electronic component packages are coincident to and in a thermal relationship with the fluid flow system. If a particular electronic component package becomes non-functional, it may be removed from the electronic enclosure without affecting either the fluid flow system or other neighboring electronic component packages.

Cooling system for electronic components

DOEpatents

Anderl, William James; Colgan, Evan George; Gerken, James Dorance; Marroquin, Christopher Michael; Tian, Shurong

2016-05-17

Embodiments of the present invention provide for non interruptive fluid cooling of an electronic enclosure. One or more electronic component packages may be removable from a circuit card having a fluid flow system. When installed, the electronic component packages are coincident to and in a thermal relationship with the fluid flow system. If a particular electronic component package becomes non-functional, it may be removed from the electronic enclosure without affecting either the fluid flow system or other neighboring electronic component packages.

Spectra of Cosmic Ray Electrons and Diffuse Gamma Rays with the Constraints of AMS-02 and HESS Data

NASA Astrophysics Data System (ADS)

Chen, Ding; Huang, Jing; Jin, Hong-Bo

2015-10-01

Recently, AMS-02 reported their results of cosmic ray (CR) observations. In addition to the AMS-02 data, we add HESS data to estimate the spectra of CR electrons and the diffuse gamma rays above TeV. In the conventional diffusion model, a global analysis is performed on the spectral features of CR electrons and the diffuse gamma rays by the GALRPOP package. The results show that the spectrum structure of the primary component of CR electrons cannot be fully reproduced by a simple power law and that the relevant break is around 100 GeV. At the 99% confidence level (C.L.) the injection indices above the break decrease from 2.54 to 2.35, but the ones below the break are only in the range of 2.746-2.751. The spectrum of CR electrons does not need to add TeV cutoff to also match the features of the HESS data. Based on the difference between the fluxes of CR electrons and their primary components, the predicted excess of CR positrons is consistent with the interpretation that these positrons originate from a pulsar or dark matter. In the analysis of the Galactic diffuse gamma rays with the indirect constraint of AMS-02 and HESS data, it is found that the fluxes of Galactic diffuse gamma rays are consistent with the GeV data of the Fermi-Large Area Telescope (LAT) in the high-latitude regions. The results indicate that inverse Compton scattering is the dominant component in the range of hundreds of GeV to tens of TeV, respectively from the high-latitude regions to the low ones, and in all of the regions of the Galaxy the flux of diffuse gamma rays is less than that of CR electrons at the energy scale of 20 TeV.

SPECTRA OF COSMIC RAY ELECTRONS AND DIFFUSE GAMMA RAYS WITH THE CONSTRAINTS OF AMS-02 AND HESS DATA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Ding; Jin, Hong-Bo; Huang, Jing, E-mail: hbjin@bao.ac.cn

2015-10-01

Recently, AMS-02 reported their results of cosmic ray (CR) observations. In addition to the AMS-02 data, we add HESS data to estimate the spectra of CR electrons and the diffuse gamma rays above TeV. In the conventional diffusion model, a global analysis is performed on the spectral features of CR electrons and the diffuse gamma rays by the GALRPOP package. The results show that the spectrum structure of the primary component of CR electrons cannot be fully reproduced by a simple power law and that the relevant break is around 100 GeV. At the 99% confidence level (C.L.) the injectionmore » indices above the break decrease from 2.54 to 2.35, but the ones below the break are only in the range of 2.746–2.751. The spectrum of CR electrons does not need to add TeV cutoff to also match the features of the HESS data. Based on the difference between the fluxes of CR electrons and their primary components, the predicted excess of CR positrons is consistent with the interpretation that these positrons originate from a pulsar or dark matter. In the analysis of the Galactic diffuse gamma rays with the indirect constraint of AMS-02 and HESS data, it is found that the fluxes of Galactic diffuse gamma rays are consistent with the GeV data of the Fermi-Large Area Telescope (LAT) in the high-latitude regions. The results indicate that inverse Compton scattering is the dominant component in the range of hundreds of GeV to tens of TeV, respectively from the high-latitude regions to the low ones, and in all of the regions of the Galaxy the flux of diffuse gamma rays is less than that of CR electrons at the energy scale of 20 TeV.« less

A High Performance COTS Based Computer Architecture

NASA Astrophysics Data System (ADS)

Patte, Mathieu; Grimoldi, Raoul; Trautner, Roland

2014-08-01

Using Commercial Off The Shelf (COTS) electronic components for space applications is a long standing idea. Indeed the difference in processing performance and energy efficiency between radiation hardened components and COTS components is so important that COTS components are very attractive for use in mass and power constrained systems. However using COTS components in space is not straightforward as one must account with the effects of the space environment on the COTS components behavior. In the frame of the ESA funded activity called High Performance COTS Based Computer, Airbus Defense and Space and its subcontractor OHB CGS have developed and prototyped a versatile COTS based architecture for high performance processing. The rest of the paper is organized as follows: in a first section we will start by recapitulating the interests and constraints of using COTS components for space applications; then we will briefly describe existing fault mitigation architectures and present our solution for fault mitigation based on a component called the SmartIO; in the last part of the paper we will describe the prototyping activities executed during the HiP CBC project.

Inverter power module with distributed support for direct substrate cooling

DOEpatents

Miller, David Harold [San Pedro, CA; Korich, Mark D [Chino Hills, CA; Ward, Terence G [Redondo Beach, CA; Mann, Brooks S [Redondo Beach, CA

2012-08-21

Systems and/or methods are provided for an inverter power module with distributed support for direct substrate cooling. An inverter module comprises a power electronic substrate. A first support frame is adapted to house the power electronic substrate and has a first region adapted to allow direct cooling of the power electronic substrate. A gasket is interposed between the power electronic substrate and the first support frame. The gasket is configured to provide a seal between the first region and the power electronic substrate. A second support frame is adapted to house the power electronic substrate and joined to the first support frame to form the seal.

PROBING DYNAMICS OF ELECTRON ACCELERATION WITH RADIO AND X-RAY SPECTROSCOPY, IMAGING, AND TIMING IN THE 2002 APRIL 11 SOLAR FLARE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fleishman, Gregory D.; Nita, Gelu M.; Gary, Dale E.

Based on detailed analysis of radio and X-ray observations of a flare on 2002 April 11 augmented by realistic three-dimensional modeling, we have identified a radio emission component produced directly at the flare acceleration region. This acceleration region radio component has distinctly different (1) spectrum, (2) light curves, (3) spatial location, and, thus, (4) physical parameters from those of the separately identified trapped or precipitating electron components. To derive evolution of physical parameters of the radio sources we apply forward fitting of the radio spectrum time sequence with the gyrosynchrotron source function with five to six free parameters. At themore » stage when the contribution from the acceleration region dominates the radio spectrum, the X-ray- and radio-derived electron energy spectral indices agree well with each other. During this time the maximum energy of the accelerated electron spectrum displays a monotonic increase with time from {approx}300 keV to {approx}2 MeV over roughly one minute duration indicative of an acceleration process in the form of growth of the power-law tail; the fast electron residence time in the acceleration region is about 2-4 s, which is much longer than the time of flight and so requires a strong diffusion mode there to inhibit free-streaming propagation. The acceleration region has a relatively strong magnetic field, B {approx} 120 G, and a low thermal density, n{sub e} {approx}< 2 Multiplication-Sign 10{sup 9} cm{sup -3}. These acceleration region properties are consistent with a stochastic acceleration mechanism.« less

Silicon Carbide High-Temperature Power Rectifiers Fabricated and Characterized

NASA Technical Reports Server (NTRS)

1996-01-01

The High Temperature Integrated Electronics and Sensors (HTIES) team at the NASA Lewis Research Center is developing silicon carbide (SiC) for use in harsh conditions where silicon, the semiconductor used in nearly all of today's electronics, cannot function. Silicon carbide's demonstrated ability to function under extreme high-temperature, high power, and/or high-radiation conditions will enable significant improvements to a far ranging variety of applications and systems. These improvements range from improved high-voltage switching for energy savings in public electric power distribution and electric vehicles, to more powerful microwave electronics for radar and cellular communications, to sensors and controls for cleaner-burning, more fuel-efficient jet aircraft and automobile engines. In the case of jet engines, uncooled operation of 300 to 600 C SiC power actuator electronics mounted in key high-temperature areas would greatly enhance system performance and reliability. Because silicon cannot function at these elevated temperatures, the semiconductor device circuit components must be made of SiC. Lewis' HTIES group recently fabricated and characterized high-temperature SiC rectifier diodes whose record-breaking characteristics represent significant progress toward the realization of advanced high-temperature actuator control circuits. The first figure illustrates the 600 C probe-testing of a Lewis SiC pn-junction rectifier diode sitting on top of a glowing red-hot heating element. The second figure shows the current-versus voltage rectifying characteristics recorded at 600 C. At this high temperature, the diodes were able to "turn-on" to conduct 4 A of current when forward biased, and yet block the flow of current ($quot;turn-off") when reverse biases as high as 150 V were applied. This device represents a new record for semiconductor device operation, in that no previous semiconductor electronic device has ever simultaneously demonstrated 600 C functionality, and 4-A turn-on and 150-V rectification. The high operating current was achieved despite severe device size limitations imposed by present-day SiC wafer defect densities. Further substantial increases in device performance can be expected when SiC wafer defect densities decrease as SiC wafer production technology matures.

The Language of Glove: Wireless gesture decoder with low-power and stretchable hybrid electronics.

PubMed

O'Connor, Timothy F; Fach, Matthew E; Miller, Rachel; Root, Samuel E; Mercier, Patrick P; Lipomi, Darren J

2017-01-01

This communication describes a glove capable of wirelessly translating the American Sign Language (ASL) alphabet into text displayable on a computer or smartphone. The key components of the device are strain sensors comprising a piezoresistive composite of carbon particles embedded in a fluoroelastomer. These sensors are integrated with a wearable electronic module consisting of digitizers, a microcontroller, and a Bluetooth radio. Finite-element analysis predicts a peak strain on the sensors of 5% when the knuckles are fully bent. Fatigue studies suggest that the sensors successfully detect the articulation of the knuckles even when bent to their maximal degree 1,000 times. In concert with an accelerometer and pressure sensors, the glove is able to translate all 26 letters of the ASL alphabet. Lastly, data taken from the glove are used to control a virtual hand; this application suggests new ways in which stretchable and wearable electronics can enable humans to interface with virtual environments. Critically, this system was constructed of components costing less than $100 and did not require chemical synthesis or access to a cleanroom. It can thus be used as a test bed for materials scientists to evaluate the performance of new materials and flexible and stretchable hybrid electronics.

The Language of Glove: Wireless gesture decoder with low-power and stretchable hybrid electronics

PubMed Central

O’Connor, Timothy F.; Fach, Matthew E.; Miller, Rachel; Root, Samuel E.; Mercier, Patrick P.

2017-01-01

This communication describes a glove capable of wirelessly translating the American Sign Language (ASL) alphabet into text displayable on a computer or smartphone. The key components of the device are strain sensors comprising a piezoresistive composite of carbon particles embedded in a fluoroelastomer. These sensors are integrated with a wearable electronic module consisting of digitizers, a microcontroller, and a Bluetooth radio. Finite-element analysis predicts a peak strain on the sensors of 5% when the knuckles are fully bent. Fatigue studies suggest that the sensors successfully detect the articulation of the knuckles even when bent to their maximal degree 1,000 times. In concert with an accelerometer and pressure sensors, the glove is able to translate all 26 letters of the ASL alphabet. Lastly, data taken from the glove are used to control a virtual hand; this application suggests new ways in which stretchable and wearable electronics can enable humans to interface with virtual environments. Critically, this system was constructed of components costing less than $100 and did not require chemical synthesis or access to a cleanroom. It can thus be used as a test bed for materials scientists to evaluate the performance of new materials and flexible and stretchable hybrid electronics. PMID:28700603

Gallium

USGS Publications Warehouse

Foley, Nora K.; Jaskula, Brian W.; Kimball, Bryn E.; Schulte, Ruth F.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

2017-12-19

Gallium is a soft, silvery metallic element with an atomic number of 31 and the chemical symbol Ga. Gallium is used in a wide variety of products that have microelectronic components containing either gallium arsenide (GaAs) or gallium nitride (GaN). GaAs is able to change electricity directly into laser light and is used in the manufacture of optoelectronic devices (laser diodes, light-emitting diodes [LEDs], photo detectors, and solar cells), which are important for aerospace and telecommunications applications and industrial and medical equipment. GaAs is also used in the production of highly specialized integrated circuits, semiconductors, and transistors; these are necessary for defense applications and high-performance computers. For example, cell phones with advanced personal computer-like functionality (smartphones) use GaAs-rich semiconductor components. GaN is used principally in the manufacture of LEDs and laser diodes, power electronics, and radio-frequency electronics. Because GaN power transistors operate at higher voltages and with a higher power density than GaAs devices, the uses for advanced GaN-based products are expected to increase in the future. Gallium technologies also have large power-handling capabilities and are used for cable television transmission, commercial wireless infrastructure, power electronics, and satellites. Gallium is also used for such familiar applications as screen backlighting for computer notebooks, flat-screen televisions, and desktop computer monitors.Gallium is dispersed in small amounts in many minerals and rocks where it substitutes for elements of similar size and charge, such as aluminum and zinc. For example, gallium is found in small amounts (about 50 parts per million) in such aluminum-bearing minerals as diaspore-boehmite and gibbsite, which form bauxite deposits, and in the zinc-sulfide mineral sphalerite, which is found in many mineral deposits. At the present time, gallium metal is derived mainly as a byproduct of the processing of bauxite ore for aluminum; lesser amounts of gallium metal are produced from the processing of sphalerite ore from three types of deposits (sediment-hosted, Mississippi Valley-type, and volcanogenic massive sulfide) for zinc. The United States is expected to meet its current and expected future needs for gallium through imports of primary, recycled, and refined gallium, as well as through domestic production of recycled and refined gallium. The U.S. Geological Survey estimates that world resources of gallium in bauxite exceed 1 billion kilograms, and a considerable quantity of gallium could be present in world zinc reserves.

Improved grating angular sensor for LISA and MGRS

NASA Astrophysics Data System (ADS)

Sun, Ke-Xun; Lu, Patrick; Byer, Robert L.

2009-03-01

LISA requires high precision angular beam pointing and telescope steering. In this paper, we report recent results for an improved grating angular sensor. We have achieved better than 0.2 nrad/Hz1/2 at 1 kHz with 14 mW of incident power, a factor of 5 improvement over our previously reported results. At 1 Hz we achieved 1-2 nrad/Hz1/2. We realized these improvements by enclosing the grating angular sensor assembly in a vacuum chamber and mounting the optics components on a zerodur glass plate, thereby lowering the noise floor at low frequencies. Furthermore, by upgrading the electronics and thus the detector power handing capability, we also investigated sensitivity scaling versus incident laser power. The results will benefit the design of grating angular sensors.

The electromagnetic environment of hospitals: how it is affected by the strength of electromagnetic fields generated both inside and outside the hospital.

PubMed

Hanada, Eisuke

2007-01-01

Most problems with the electromagnetic environment of medical institutions have been related to radiated electromagnetic fields and have been constructed from reports about electromagnetic interference (EMI) with electronic medical equipment by the radio waves emitted from mobile telephone handsets. However, radiated electromagnetic fields are just one of the elements. For example, little attention has been placed on problems with the electric power source. Apparatus for clinical treatment and diagnosis that use electric power sources have come into wide use in hospitals. Hospitals must pay careful attention to all elements of the electromagnetic environment. Herein, I will show examples of measurements and measuring methods for radiated electromagnetic fields, static magnetic fields, and power-source noise, common components of the medical electromagnetic environment.

Carbon-Nanotube Schottky Diodes

NASA Technical Reports Server (NTRS)

Manohara, Harish; Wong, Eric; Schlecht, Erich; Hunt, Brian; Siegel, Peter

2006-01-01

Schottky diodes based on semiconducting single-walled carbon nanotubes are being developed as essential components of the next generation of submillimeter-wave sensors and sources. Initial performance predictions have shown that the performance characteristics of these devices can exceed those of the state-of-the-art solid-state Schottky diodes that have been the components of choice for room-temperature submillimeter-wave sensors for more than 50 years. For state-of-the-art Schottky diodes used as detectors at frequencies above a few hundred gigahertz, the inherent parasitic capacitances associated with their semiconductor junction areas and the resistances associated with low electron mobilities limit achievable sensitivity. The performance of such a detector falls off approximately exponentially with frequency above 500 GHz. Moreover, when used as frequency multipliers for generating signals, state-of-the-art solid-state Schottky diodes exhibit extremely low efficiencies, generally putting out only micro-watts of power at frequencies up to 1.5 THz. The shortcomings of the state-of-the-art solid-state Schottky diodes can be overcome by exploiting the unique electronic properties of semiconducting carbon nanotubes. A single-walled carbon nanotube can be metallic or semiconducting, depending on its chirality, and exhibits high electron mobility (recently reported to be approx.= 2x10(exp 5)sq cm/V-s) and low parasitic capacitance. Because of the narrowness of nanotubes, Schottky diodes based on carbon nanotubes have ultra-small junction areas (of the order of a few square nanometers) and consequent junction capacitances of the order of 10(exp -18) F, which translates to cutoff frequency >5 THz. Because the turn-on power levels of these devices are very low (of the order of nano-watts), the input power levels needed for pumping local oscillators containing these devices should be lower than those needed for local oscillators containing state-of-the-art solid-state Schottky diodes.

Integrated Vehicle Thermal Management - Combining Fluid Loops in Electric Drive Vehicles (Presentation)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rugh, J. P.

2013-07-01

Plug-in hybrid electric vehicles and electric vehicles have increased vehicle thermal management complexity, using separate coolant loop for advanced power electronics and electric motors. Additional thermal components result in higher costs. Multiple cooling loops lead to reduced range due to increased weight. Energy is required to meet thermal requirements. This presentation for the 2013 Annual Merit Review discusses integrated vehicle thermal management by combining fluid loops in electric drive vehicles.

High temperature furnace

DOEpatents

Borkowski, Casimer J.

1976-08-03

A high temperature furnace for use above 2000.degree.C is provided that features fast initial heating and low power consumption at the operating temperature. The cathode is initially heated by joule heating followed by electron emission heating at the operating temperature. The cathode is designed for routine large temperature excursions without being subjected to high thermal stresses. A further characteristic of the device is the elimination of any ceramic components from the high temperature zone of the furnace.

Light weight Heat-Sink, Based on Phase-Change-Material for a High powered - Time limited application

NASA Astrophysics Data System (ADS)

Leibovitz, Johnathan

2002-01-01

When designing components for an aerospace application, whether it is an aircraft, satellite, space station or a launcher - a major considered parameter is its weight . For a combat aircraft, an addition of such a lightweight Heat sink to a high power component, can extend significantly avionics performance at very high altitude - when cooling means are poor. When dealing with a satellite launcher, each pound saved from the launcher in favor of the satellite - may contribute, for instance, several months of satellite life. The solution presented in this paper deals with an electronic device producing high power, for limited time and requires relatively low temperature base plate. The requirements demand that a base plate temperature should not exceed 70°c while exposed to a heat- flux of about 1.5W/cm^2 from an electronic device, during approximately 14 minutes. The classical solution for this transient process requires an Aluminum block heat sink of about 1100 grams . The PCM based heat-sink gives the solution for this case with about 400 grams only with a compact package. It also includes an option for cooling the system by forced convection (and in principle by radiation), when those means of heat dissipation - are available. The work includes a thermal analysis for the Aluminum - PCM heat sink and a series of validation tests of a model. The paper presents results of the analysis and results of the tests, including comparison to the classical robust solution. A parametric performance envelope for customizing to other potential applications is presented as well.

Electron-phonon heat exchange in quasi-two-dimensional nanolayers

NASA Astrophysics Data System (ADS)

Anghel, Dragos-Victor; Cojocaru, Sergiu

2017-12-01

We study the heat power P transferred between electrons and phonons in thin metallic films deposited on free-standing dielectric membranes. The temperature range is typically below 1 K, such that the wavelengths of the excited phonon modes in the system is large enough so that the picture of a quasi-two-dimensional phonon gas is applicable. Moreover, due to the quantization of the components of the electron wavevectors perpendicular to the metal film's surface, the electrons spectrum forms also quasi two-dimensional sub-bands, as in a quantum well (QW). We describe in detail the contribution to the electron-phonon energy exchange of different electron scattering channels, as well as of different types of phonon modes. We find that heat flux oscillates strongly with thickness of the film d while having a much smoother variation with temperature (Te for the electrons temperature and Tph for the phonons temperature), so that one obtains a ridge-like landscape in the two coordinates, (d, Te) or (d, Tph), with crests and valleys aligned roughly parallel to the temperature axis. For the valley regions we find P ∝ Te3.5 - Tph3.5. From valley to crest, P increases by more than one order of magnitude and on the crests P cannot be represented by a simple power law. The strong dependence of P on d is indicative of the formation of the QW state and can be useful in controlling the heat transfer between electrons and crystal lattice in nano-electronic devices. Nevertheless, due to the small value of the Fermi wavelength in metals, the surface imperfections of the metallic films can reduce the magnitude of the oscillations of P vs. d, so this effect might be easier to observe experimentally in doped semiconductors.

An Adaptable Power System with Software Control Algorithm

NASA Technical Reports Server (NTRS)

Castell, Karen; Bay, Mike; Hernandez-Pellerano, Amri; Ha, Kong

1998-01-01

A low cost, flexible and modular spacecraft power system design was developed in response to a call for an architecture that could accommodate multiple missions in the small to medium load range. Three upcoming satellites will use this design, with one launch date in 1999 and two in the year 2000. The design consists of modular hardware that can be scaled up or down, without additional cost, to suit missions in the 200 to 600 Watt orbital average load range. The design will be applied to satellite orbits that are circular, polar elliptical and a libration point orbit. Mission unique adaptations are accomplished in software and firmware. In designing this advanced, adaptable power system, the major goals were reduction in weight volume and cost. This power system design represents reductions in weight of 78 percent, volume of 86 percent and cost of 65 percent from previous comparable systems. The efforts to miniaturize the electronics without sacrificing performance has created streamlined power electronics with control functions residing in the system microprocessor. The power system design can handle any battery size up to 50 Amp-hour and any battery technology. The three current implementations will use both nickel cadmium and nickel hydrogen batteries ranging in size from 21 to 50 Amp-hours. Multiple batteries can be used by adding another battery module. Any solar cell technology can be used and various array layouts can be incorporated with no change in Power System Electronics (PSE) hardware. Other features of the design are the standardized interfaces between cards and subsystems and immunity to radiation effects up to 30 krad Total Ionizing Dose (TID) and 35 Mev/cm(exp 2)-kg for Single Event Effects (SEE). The control algorithm for the power system resides in a radiation-hardened microprocessor. A table driven software design allows for flexibility in mission specific requirements. By storing critical power system constants in memory, modifying the system code for other programs is simple. These constants can be altered also by ground command, or in response to an anomolous event. All critical power system functions have backup hardware functions to prevent a software or computer glitch from propagating. A number of battery charge control schemes can be implemented by selecting the proper control terms in the code. The architecture allows the design engineer to tune the system response to various system components and anticipated load profiles without costly alterations. A design trade was made with the size, weight and power dissipation of the electronics versus the performance of the power bus to load variations. Linear, fine control is maintained with a streamlined electronics design. This paper describes the hardware design as well as the software control algorithm. The challenges of closing the system control loop digitally is discussed. Control loop margin and power system performance is presented. Lab measurements are shown and compared to the system response of a hardware model running actual flight software.