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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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DOE OSTI2014

SU-E-T-494: A MOSFET-Based In-Vivo Dosimetry System for MR Image-Guided Radiation Therapy (MR-IGRT)

Purpose: To determine if a MOSFET based in-vivo dosimetry system can be used for patients undergoing MR-IGRT. Methods: Standard and high sensitivity MOSFET detectors were used for in-field and out-of-field measurements respectively. The systems were benchmarked and calibrated against a calibrated ionization chamber on a standard 6 MV linear accelerator, and then on the MR-IGRT system. Known doses were delivered to a water phantom with the MOSFETs placed between the top of the phantom and underneath a layer of bolus and water equivalent plastic, using a 6 MV beam and a {sup 6} {sup 0}Co MR-IGRT beam. The latter was performed with and without real-time MRI-guidance during the beam delivery (MRIGRT). Results: The in-field dosimeter response was linear from 50-500 cGy with little evidence of energy dependence or change in response due to the permanent static magnetic field of the MR-IGRT system. The detector response varied by < 2% between 6 MV and {sup 6} {sup 0}Co without image guided delivery. The out-of-field dosimeter response was linear from 1-50 cGy; however the detectors did display dose rate and energy dependence as the response varied by > 20% depending on distance from isocenter used during calibration. Therefore, to use the dosimeters for out-of-field measurements they must be calibrated out-of-field. Regardless of the detector orientation in the coronal plan, the response of the MOSFETs during MRI-guided delivery increased by 5% due to induced currents from the dynamic magnetic field present with image guidance. During the MRI-guided delivery, some loss in image quality was seen when the MOSFETs were present in the imaging plane. This was mitigated by using a handheld reader without a transmitting wireless receiver. Conclusion: A MOSFET-based in-vivo dosimetry system can be used for patients receiving MR-IGRT; however the change in detector response due to the dynamic magnetic field requires a special calibration.

07 ISOTOPE AND RADIATION SOURCES↗

DOE OSTI2024

Summary of Jefferson Lab LDRD on FFA@CEBAF Beam Dynamics Simulations

As Thomas Jefferson National Accelerator Facility (Jefferson Lab) looks toward the future, we are considering expanding our energy reach by using Fixed-Field Alternating Gradient (FFA) technology. Significant efforts have been made to design a hybrid accelerator which combines conventional recirculating electron LINAC design with permanent magnet-based FFA technology to increase the number of beam recirculations, and thus the energy. In an effort to further this progress, Jefferson Lab awarded a Laboratory Directed Research and Development (LDRD) grant to focus not on the design, but on detailed simulations of the designs created by the larger collaboration. This document will summarize the work performed during this LDRD, and direct the reader to other proceedings which describe elements of the work in greater detail.

Deitrick, K.↗

DOE OSTI2011

Hydropower from Wastewater

The project described in this report evaluates the potential for building a business around harvesting energy in wastewater effluent streams. This business could easily grow into other markets, notably the potable public water supply in which pressure reduction valves are used to throttle (reduce) the pressure by dissipating energy rather than capturing it. Industrial processes that are heavy users of water are also likely candidates.

13 HYDRO ENERGY↗

DOE OSTI2012

Sustainable Transportation Program 2011 Annual Report

Highlights of selected research and development efforts at Oak Ridge National Laboratory funded by the Vehicle Technologies Program, Biomass Program, and Hydrogen and Fuel Cells Program of the Department of Energy, Office of Energy Efficiency and Renewable Energy; and the Department of Transportation.

02 PETROLEUM↗

DOE OSTI2012

Advanced Gearless Drivetrain - Phase I Technical Report

Boulder Wind Power (BWP) collaborated with the National Renewable Energy Laboratory (NREL) in Golden, Colorado, to demonstrate the economics of scaling an advanced gearless drivetrain technology to 6MW (and larger) turbine applications. The project goal was to show that this advanced drivetrain technology enables a cost of energy of less than $\$$0.10/kWH in offshore applications. This drivetrain technology achieves this Cost of Energy (COE) advantage via a 70% greater torque density versus current state-of-the-art drivetrain technologies. In addition, a new dynamically compliant design strategy is required to optimize turbine system-level COE. The BWP generator is uniquely suited for this new design strategy. This project developed a concept design for a 6MW drivetrain and culminated in a plan for a system-level test of this technology at 3MW scale. The project further demonstrated the advantage of the BWP drivetrain with increasing power ratings, with conceptual designs through 10 MW.

17 WIND ENERGY↗

DOE OSTI2012

Advanced Motors

Transportation energy usage is predicted to increase substantially by 2020. Hybrid vehicles and fuel cell powered vehicles are destined to become more prominent as fuel prices rise with the demand. Hybrid and fuel cell vehicle platforms are both dependent on high performance electric motors. Electric motors for transportation duty will require sizeable low-speed torque to accelerate the vehicle. As motor speed increases, the torque requirement decreases which results in a nearly constant power motor output.