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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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A review of the radiation effects investigation capabilities of the JPL Dynamitron Accelerator Facility are discussed. A process for its use in performing total ionizing dose (TID) studies are outlined. The results of radiation effects in complicated test systems where device effects may occur due to local system irradiation are also presented.
The two main objectives of this trade study are characterizing the mission radiation environment for multiple Design Reference Missions (DRM) and analysis of radiation effects on avionics with the goal of producing radiation tolerant Neuromorphic Computing processor chips with innovative radiation-induced fault mitigation. The NASA process for defining radiation requirements for flight avionics is applied to this domain. The effects of trapped protons and electrons in the Van Allen radiation belts predominates in Low-Earth-Orbit (LEO) and the solar wind, solar flares and Galactic Cosmic Rays (GCRs) are the dominant radiation challenge in the open space between the planets of our solar system. The nature and energy of the particles that cause circuit upset and failure is very different in the two regimes. Two results are produced from the radiation models: determining the Total Integrated Dose (TID) experienced by avionics for a given DRM and predicting the Single Event Effects (SEE) rates for avionics during high rate exposure. These tools are applied to existing semiconductors and can be used for predicting the radiation performance of future semiconductors based on early radiation testing of new devices.
The Oak Ridge National Laboratory (ORNL) and the US Department of Energy Nuclear Physics Program have built a high-resolution Electromagnetic Isotope Separator (EMIS) as a prototype for reestablishing a US based enrichment capability for stable isotopes. ORNL has over 60 years of experience providing enriched stable isotopes and related technical services to the international accelerator target community, as well as medical, research, industrial, national security, and other communities. ORNL is investigating the combined use of electromagnetic and gas centrifuge isotope separation technologies to provide research quantities (milligram to several kilograms) of enriched stable isotopes. In preparation for implementing a larger scale production facility, a 10 mA high-resolution EMIS prototype has been built and tested. Initial testing of the device has simultaneously collected greater than 98% enriched samples of all the molybdenum isotopes from natural abundance feedstock.
The National Wind Technology Center (NWTC) at the National Renewable Energy Laboratory (NREL) is helping guide our nation's research-and-development effort in offshore renewable energy, which includes: Design, modeling, and analysis tools; Device and component testing; Resource characterization; Economic modeling and analysis; Grid integration.
The Internal Short Circuit (ISC) device enables critical battery safety verification. With the aluminum interstitial heat sink between the cells, normal trigger cells cannot be driven into thermal runaway without excessive temperature bias of adjacent cells. With an implantable, on-demand ISC device, thermal runaway tests show that the conductive heat sinks protected adjacent cells from propagation. High heat dissipation and structural support of Al heat sinks show high promise for safer, higher performing batteries.
As new loads such as rooftop photovoltaics, electric vehicles and other distributed energy resources become commonplace on the distribution grid, the stress on already aging assets begins to escalate. This increased loading and changing dynamics can exacerbate failure rates. While traditional monitoring efforts focus on transmission and generation assets, utilities are now beginning to pay close attention to distribution assets in order to increase reliability indices and reduce cost from unexpected outages. This research develops low-cost and scalable methods to monitoring the health of a critical distribution grid asset: the service transformer. Existing methods in literature are either invasive and thus difficult to implement or require the device to be tested offline in an expensive lab setting. Data from the ubiquitous smart meter as well as a novel Bluetooth based transformer monitor are leveraged to automatically notify the utility of deteriorating or damaged transformers. Voltage, temperature, and vibration are some of the signals measured and analyzed by the proposed algorithms to predict transformer failures. Furthermore, these algorithms are designed to keep the implementation and processing costs low by taking advantage of edge computing where possible.
A new high energy polarized photon source is being constructed for the GlueX experiment at Jefferson Lab. Linear polarization is obtained using coherent bremsstrahlung from an oriented diamond radiator. By collimating the photon beam to a fraction of the characteristic bremsstrahlung angle $m_e/E_0$, linear polarization of 40\% is obtained at a photon energy of 9~GeV, for an incident electron beam of 12~GeV. Active stabilization of the photon beam spot on the collimator face is required in order to establish and maintain the alignment of the beam on the collimator axis with the required degree of accuracy. A photon beam centroid monitor has been developed for this purpose, based on the design of an electron beam halo detector that was invented for use at SLAC 30 years ago. Beam tests of this device in Hall B at 6 GeV show that it has the required bandwidth and sensitivity to be used in an active feedback loop in the electron beam steering controls. Such a feedback circuit is capable of locking the Hall D photon beam on the Hall D collimator with the required accuracy for GlueX at frequencies up to 1~kHz, over a wide range in beam current.
MARIA reactor is an open-pool research reactor what gives the chance to install uranium fission converter on the periphery of the core. It could be installed far enough not to induce reactivity of the core but close enough to produce high flux of fast neutrons. Special design of the converter is now under construction. It is planned to set the research stand based on such uranium converter in the near future: in 2015 MARIA reactor infrastructure should be ready (preparation started in 2013), in 2016 the neutron beam starts and in 2017 opening the stand for material and biological research or for medical training concerning BNCT. Unused for many years, horizontal channel number H2 at MARIA research rector in Poland, is going to be prepared as a part of unique stand. The characteristics of the neutron beam will be significant advantage of the facility. High flux of neutrons at the level of 2x10{sup 9} cm{sup -2}s{sup -1} will be obtainable by uranium neutron converter located 90 cm far from the reactor core fuel elements (still inside reactor core basket between so called core reflectors). Due to reaction of core neutrons with converter U{sub 3}Si{sub 2} material it will produce high flux of fast neutrons. After conversion neutrons will be collimated and moderated in the channel by special set of filters and moderators. At the end of H2 channel i.e. at the entrance to the research room neutron energy will be in the epithermal energy range with neutron intensity at least at the level required for BNCT (2x10{sup 9} cm{sup -2}s{sup -1}). For other purposes density of the neutron flux could be smaller. The possibility to change type and amount of installed filters/moderators which enables getting different properties of the beam (neutron energy spectrum, neutron-gamma ratio and beam profile and shape) is taken into account. H2 channel is located in separate room which is adjacent to two other empty rooms under the preparation for research laboratories (200 m2). It is planned to create fully equipped complex facility possible to perform various experiments on the intensive neutron beam. Epithermal neutron beam enables development across the full spectrum of materials research for example shielding concrete tests or electronic devices construction improvement. Due to recent reports on the construction of the accelerator for the Boron Neutron Capture Therapy (BNCT) it has the opportunity to become useful and successful method in the fight against brain and other types of cancers not treated with well known medical methods. In Europe there is no such epithermal neutron source which could be used throughout the year for training and research for scientist working on BNCT what makes the stand unique in Europe. Also our research group which specializes in mixed radiation dosimetry around nuclear and medical facilities would be able to carry out research on new detectors and methods of measurements for radiological protection and in-beam (therapeutic) dosimetry. Another group of scientists from National Centre for Nuclear Research, where MARIA research reactor is located, is involved in research of gamma detector systems. There is an idea to develop Prompt-gamma Single Photon Emission Computed Tomography (Pg- SPECT). This method could be used as imaging system for compounds emitting gamma rays after nuclear reaction with thermal neutrons e.g. for boron concentration in BNCT. Inside the room, where H2 channel is located, there is another horizontal channel - H1 which is also unused. Simultaneously with the construction of the H2 stand it will be possible to create special pneumatic horizontal mail inside the H1 channel for irradiation material samples in the vicinity of the core i.e. in the distal part of the H1 channel. It might expand the scope of research at the planned neutron station. Secondly it is planned to equip both stands with moveable positioning system, video system and facilities to perform animal experiments (anaesthesia, vital signs control, imaging devices, positioning). These all above make constructed station unique in the world (uranium fission converter-based beam) and the only one of such intense neutron beam in the Europe. Moreover implementation of the station would allow the development of research on a number of issues for researchers from all over the Europe. One of very important advantages of the station is undisturbed exploitation of the reactor and other vertical and horizontal channels. MARIA reactor operates 6000 hours per year and that amount of time will be achievable for research on the neutron station. It have to be underlined that new neutron station will work parallel to all another ventures. (authors)
As a prototype of future instrumented material experiments in the Jules Horowitz Reactor (JHR), the MELODIE project was launched in 2009 by the CEA in collaboration with VTT. Being designed as a biaxial creep experiment with online capability, MELODIE is able to apply an online-controlled biaxial loading on a LWR clad sample up to 120 MPa and to perform an online measurement of its biaxial deformation. An important experimental challenge was to perform reliably accurate measurements under the high nuclear heat load of in-core locations while keeping within their tight space. For that purpose, specific sensors were co-designed with and built by IFE Halden. Manufacturing of the MELODIE components was completed one year ago. The complexity of its in-pile section and of the pressurization system requested a step-by-step tuning of the setup. The toughest part of this process dealt with the Diameter gauge which required a partial redesign to take into account unexpected and unwanted electromagnetic interactions with the hosting device. Final cold performance tests of the on-board instrumentation will be presented. The MELODIE device is now ready and irradiation should start in OSIRIS reactor this spring. (authors)
A visionics device creates a pictorial representation of the external scene for the pilot. The ultimate objective of these systems may be to electronically generate a form of Visual Meteorological Conditions (VMC) to eliminate weather or time-of-day as an operational constraint and provide enhancement over actual visual conditions where eye-limiting resolution may be a limiting factor. Empirical evidence has shown that the total system delays or latencies including the imaging sensors and display systems, can critically degrade their utility, usability, and acceptability. Definitions and measurement techniques are offered herein as common test and evaluation methods for latency testing in visionics device applications. Based upon available data, very different latency requirements are indicated based upon the piloting task, the role in which the visionics device is used in this task, and the characteristics of the visionics cockpit display device including its resolution, field-of-regard, and field-of-view. The least stringent latency requirements will involve Head-Up Display (HUD) applications, where the visionics imagery provides situational information as a supplement to symbology guidance and command information. Conversely, the visionics system latency requirement for a large field-of-view Head-Worn Display application, providing a Virtual-VMC capability from which the pilot will derive visual guidance, will be the most stringent, having a value as low as 20 msec.
We propose a network architecture with a separate quantum dataplane and a conventional control plane: (a) Quantum Data Plane: The Quantum Data plane consists of links of dark fibers connecting quantum switches and repeaters, which in turn, connect to quantum computers, memory and sensors. Since the current reach is limited to local areas, it will begin as a collection of site networks at laboratories, (b) Conventional Control Plane: The Control plane provides management access to quantum devices for configuration and provisioning via control nodes with firewall and encryption capabilities. Continuous Test and Transition Infrastructure: We propose an infrastructure with a control plane connecting multiple sites via encrypted tunnels over conventional networks consisting of the following: (a) Site Quantum Networks: Individual site networks supported by their fiber plants connect laboratories that house and connect to their quantum devices for testing and interoperability.(b) Site Control Planes: Sites are connected over individual control planes with control hosts with Software Defined Networking capabilities, which can be peered with other networks via ESnet.(c) Progressive Expansion: Initially, sites will develop individual data planes with their specific quantum devices and fiber connections, and mechanisms to interface with conventional networks. They progressively expand and interconnect, under a wide-area ecosystem of peered control planes for device testing, interoperability development and roll off into production environments.
Purpose: The monitoring and management of radio frequency (RF) exposure is critical for ensuring magnetic resonance imaging (MRI) safety. Commercial MRI scanners can overestimate specific absorption rates (SAR) and improperly restrict clinical MRI scans or the application of new MRI sequences, while underestimation of SAR can lead to tissue heating and thermal injury. Accurate scanner-independent RF dosimetry is essential for measuring actual exposure when SAR is critical for ensuring regulatory compliance and MRI safety, for establishing RF exposure while evaluating interventional leads and devices, and for routine MRI quality assessment by medical physicists. However, at present there are no scanner-independent SAR dosimeters. Methods: An SAR dosimeter with an RF transducer comprises two orthogonal, rectangular copper loops and a spherical MRI phantom. The transducer is placed in the magnet bore and calibrated to approximate the resistive loading of the scanner's whole-body birdcage RF coil for human subjects in Philips, GE and Siemens 3 tesla (3T) MRI scanners. The transducer loop reactances are adjusted to minimize interference with the transmit RF field (B{sub 1}) at the MRI frequency. Power from the RF transducer is sampled with a high dynamic range power monitor and recorded on a computer. The deposited power is calibrated and tested on eight different MRI scanners. Whole-body absorbed power vs weight and body mass index (BMI) is measured directly on 26 subjects. Results: A single linear calibration curve sufficed for RF dosimetry at 127.8 MHz on three different Philips and three GE 3T MRI scanners. An RF dosimeter operating at 123.2 MHz on two Siemens 3T scanners required a separate transducer and a slightly different calibration curve. Measurement accuracy was ∼3%. With the torso landmarked at the xiphoid, human adult whole‑body absorbed power varied approximately linearly with patient weight and BMI. This indicates that whole-body torso SAR is on average independent of the imaging subject, albeit with fluctuations. Conclusions: Our 3T RF dosimeter and transducers accurately measure RF exposure in body-equivalent loads and provide scanner-independent assessments of whole-body RF power deposition for establishing safety compliance useful for MRI sequence and device testing.
We present the design, calibration, and testing of a magnetic tweezers device that employs two pairs of permanent neodymium iron boron magnets surrounded by low-carbon steel focusing tips to apply large forces to soft materials for microrheology experiments. Our design enables the application of forces in the range of 1-1800 pN to {approx}4.5 {mu}m paramagnetic beads using magnet-bead separations in the range of 0.3-20 mm. This allows the use of standard coverslips and sample geometries. A high speed camera, custom LED-based illumination scheme, and mechanically stabilized measurement platform are employed to enable the measurement of materials with viscoelastic moduli as high as {approx}1 kPa.
Room temperature and elevated temperature preliminary ultrasonic measurements and capsule design, construction and testing - ultrasonic temperature measuring device
In this presentation, the driving factors changing the world of single-event effects (SEE) testing will be discussed. This includes both semiconductor technological advances and morphing space system philosophies. Considerations for meeting these new challenges will then follow.
A temperature sensor qualification device is undergoing development and testing in order to qualify temperature sensors for advanced reactor metrology applications. This device will provide National Institute of Standards and Technology (NIST) traceable performance testing of temperature sensors while under the high radiation environments experienced while in-core. This is completed by utilizing retractable sensors which transfer the measurements from ex-core to in-core sensors. A detailed discussion of the uncertainty propagation associated with this comparative process is provided. Experimental testing of the temperature distribution occurring in the device has begun and is reported on. It is pertinent to minimize this temperature distribution to prevent variation in sensor measurements. This variation will be indistinguishable from sensor drift for in-pile applications and would result in unnecessarily conservative uncertainty bounds.
Purpose: The protective effects of induced or even accidental hypothermia on the human body are widespread with several medical uses currently under active research. In vitro experiments using human cell lines have shown hypothermia provides a radioprotective effect that becomes more pronounced at large, single-fraction doses common to SBRT treatments. Relevant to prostate SBRT, this work details the fabrication and testing of a 3D-printed cooling device to facilitate the investigation of the radioprotective effect of local hypothermia on the rat rectum. Methods: A 3cm long, two-channel rectal cooling device was designed in SOLIDWORKS CAD for 3D printing. The water intake nozzle is connected to a 1mm diameter brass pipe from which water flows and circulates back around to the exit nozzle. Both nozzles are connected by plastic tubing to a water chiller pump. Following leak-proof testing, fiber optic temperature probes were used to evaluate the temperature over time when placed adjacent to the cooling device within a rat rectum. MRI thermometry characterized the relative temperature distribution in concentric ROIs surrounding the probe. CBCT images from a small-animal irradiator were evaluated for imaging artifacts which could affect Monte Carlo dose calculations during treatment planning. Results: The rectal temperature adjacent to the cooling device decreased from body temperature (37°C) to 15°C in 10–20 minutes from device insertion. Rectal temperature was maintained at 15±3°C during active cooling. MRI thermometry tests revealed a steep temperature gradient with increasing distance from the cooling device, with the desired temperature range maintained within the surrounding few millimeters. Conclusion: A 3D printed rectal cooling device was fabricated for the purpose of inducing local hypothermia in rat rectums. Rectal cooling capabilities were characterized in-vivo to facilitate an investigation of the radioprotective effect of hypothermia for late rectal toxicity following a single large dose of radiation. Funding support provided by RSNA research seed grant.
The WEC-Sim project is currently on track, having met both the SNL and NREL FY14 Milestones, as shown in Table 1 and Table 2. This is also reflected in the Gantt chart uploaded to the WEC-Sim SharePoint site in the FY14 Q4 Deliverables folder. The work completed in FY14 includes code verification through code-to-code comparison (FY14 Q1 and Q2), preliminary code validation through comparison to experimental data (FY14 Q2 and Q3), presentation and publication of the WEC-Sim project at OMAE 2014 [1], [2], [3] and GMREC/METS 2014 [4] (FY14 Q3), WEC-Sim code development and public open-source release (FY14 Q3), and development of a preliminary WEC-Sim validation test plan (FY14 Q4). This report presents the preliminary Validation Testing Plan developed in FY14 Q4. The validation test effort started in FY14 Q4 and will go on through FY15. Thus far the team has developed a device selection method, selected a device, and placed a contract with the testing facility, established several collaborations including industry contacts, and have working ideas on the testing details such as scaling, device design, and test conditions.