Lateral Power Mosfets Hardened Against Single Event Radiation Effects

The underlying physical mechanisms of destructive single event effects (SEE) from heavy ion radiation have been widely studied in traditional vertical double-diffused power MOSFETs (VDMOS). Recently lateral double-diffused power MOSFETs (LDMOS), which inherently provide lower gate charge than VDMOS, have become an attractive option for MHz-frequency DC-DC converters in terrestrial power electronics applications [1]. There are growing interests in extending the LDMOS concept into radiation-hard space applications. Since the LDMOS has a device structure considerably different from VDMOS, the well studied single event burn-out (SEB) or single event gate rapture (SEGR) response of VDMOS cannot be simply assumed for LDMOS devices without further investigation. A few recent studies have begun to investigate ionizing radiation effects in LDMOS devices, however, these studies were mainly focused on displacement damage and total ionizing dose (TID) effects, with very limited data reported on the heavy ion SEE response of these devices [2]-[5]. Furthermore, the breakdown voltage of the LDMOS devices in these studies was limited to less than 80 volts (mostly in the range of 20-30 volts), considerably below the voltage requirement for some space power applications. In this work, we numerically and experimentally investigate the physical insights of SEE in two different fabricated LDMOS devices designed by the author and intended for use in radiation hard applications. The first device is a 24 V Resurf LDMOS fabricated on P-type epitaxial silicon on a P+ silicon substrate. The second device is a iv much different 150 V SOI Resurf LDMOS fabricated on a 1.0 micron thick N-type silicon-on-insulator substrate with a 1.0 micron thick buried silicon dioxide layer on an N-type silicon handle wafer. Each device contains internal features, layout techniques, and process methods designed to improve single event and total ionizing dose radiation hardness. Technology computer aided design (TCAD) software was used to develop the transistor design and fabrication process of each device and also to simulate the device response to heavy ion radiation. Using these simulations in conjunction with experimentally gathered heavy ion radiation test data, we explain and illustrate the fundamental physical mechanisms by which destructive single event effects occur in these LDMOS devices. We also explore the design tradeoffs for making an LDMOS device resistant to destructive single event effects, both in terms of electrical performance and impact on other radiation hardness metric

Program evaluation utilization in Canada and its relationship to evaluation process, evaluator and decision context variables.

Data on the extent and type of program evaluation utilization in a sample of recent Canadian program evaluations were analyzed and then assessed with the characteristics of the evaluation processes employed, the evaluators who conducted the evaluations and the decision contexts in which the evaluations were performed. Surveys were mailed to all members of the Canadian Evaluation Society (CES) and the Program Evaluation Section of the Canadian Psychological Association (PES-CPA) during the fall of 1988. These individuals were followed up using procedures prescribed by Dillman (1978) resulting in a response rate of 68%. Additional data were obtained by mailing surveys to the department heads of 135 Canadian university departments. This mailing was not followed up and produced a response rate of 21%. A total of 332 completed surveys was returned from all sources. Program evaluation utilization was reported to be very extensive with 98% percent of this sample reporting utilization of some type. The most frequently occurring type of utilization was conceptual utilization (65%), followed by instrumental utilization (55%) and persuasive utilization (40%). A single type of utilization was reported in 47% of cases, two types in 42% of cases and all three in 10% of cases. The occurrence of each of the three types of utilization was related to different patterns of the evaluation process, evaluator and decision context variables with no one group of variables dominating the analyses. Finally, findings from research on correlates of American evaluation utilization were not replicated in the present study. There was partial support for the Patton et al. (1978) finding that the identification of a key decision maker to take responsibility for utilization was a key factor in determining utilization. Implications for evaluation practice and suggestions for future research were discussed within the context of the current study\u27s results.Dept. of Psychology. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1991 .S573. Source: Dissertation Abstracts International, Volume: 53-01, Section: B, page: 0597. Thesis (Ph.D.)--University of Windsor (Canada), 1991

Turbine Powered Simulator Calibration and Testing for Hybrid Wing Body Powered Airframe Integration

Propulsion airframe integration testing on a 5.75% scale hybrid wing body model us- ing turbine powered simulators was completed at the National Full-Scale Aerodynamics Complex 40- by 80-foot test section. Four rear control surface con gurations including a no control surface de ection con guration were tested with the turbine powered simulator units to investigate how the jet exhaust in uenced the control surface performance as re- lated to the resultant forces and moments on the model. Compared to ow-through nacelle testing on the same hybrid wing body model, the control surface e ectiveness was found to increase with the turbine powered simulator units operating. This was true for pitching moment, lift, and drag although pitching moment was the parameter of greatest interest for this project. With the turbine powered simulator units operating, the model pitching moment was seen to increase when compared to the ow-through nacelle con guration indicating that the center elevon and vertical tail control authority increased with the jet exhaust from the turbine powered simulator units

Project Columbiad: Reestablishment of human presence on the Moon

In response to the Report of the Advisory Committee on the future of the U.S. Space Program and a request from NASA's Exploration Office, the MIT Hunsaker Aerospace Corporation (HAC) conducted a feasibility study, known as Project Columbiad, on reestablishing human presence on the Moon before the year 2000. The mission criteria established were to transport a four person crew to the lunar surface at any latitude and back to Earth with a 14-28 day stay on the lunar surface. Safety followed by cost of the Columbiad Mission were the top level priorities of HAC. The resulting design has a precursor mission that emplaces the required surface payloads before the piloted mission arrives. Both the precursor and piloted missions require two National Launch System (NLS) launches. Both the precursor and piloted missions have an Earth orbit rendezvous (EOR) with a direct transit to the Moon post-EOR. The piloted mission returns to Earth via a direct transit. Included among the surface payloads preemplaced are a habitat, solar power plant (including fuel cells for the lunar night), lunar rover, and mecanisms used to cover the habitat with regolith (lunar soil) in order to protect the crew members from severe solar flare radiation

Ascent Aerodynamic Force and Moment Database Development for the Space Launch System

The Space Launch System Aerodynamics Task Team is responsible for delivering aerodynamic force and moment databases from liftoff through ascent until the rocket leaves the Earths atmosphere. The process for developing the ascent portion of this database is described in the current paper. The data used to develop the database were generated using a combination of wind tunnel testing and CFD simulations. The details of the wind tunnel testing performed at the NASA Ames Unitary Plan Wind Tunnel and CFD simulations performed using FUN3D at wind tunnel and flight conditions are discussed, and comparisons of these data sets are provided. The methods used for converting the source data into the final database response surfaces with corresponding uncertainty are also detailed

Experimental Evaluation of Inlet Distortion on an Ejector Powered Hybrid Wing Body at Take-off and Landing Conditions

As part of the NASA Environmentally Responsible Aircraft project, an ultra high bypass ratio engine integration on a hybrid wing body demonstration was planned. The goal was to include engine and airframe integration concepts that reduced fuel consumption by at least 50% while still reducing noise 42 db cumulative on the ground. Since the engines would be mounted on the upper surface of the aft body of the aircraft, the inlets may be susceptible to vortex ingestion from the wing leading edge at high angles of attack and sideslip, and separated wing/body flow. Consequently, experimental and computational studies were conducted to collect flow surveys useful for characterizing engine operability. The wind tunnel tests were conducted at two NASA facilities, the 14- by 22-foot at NASA Langley and the 40- by 80-foot at NASA Ames Research Center. The test results included in this paper show that the distortion and pressure recovery levels were acceptable for engine operability. The CFD studies conducted to compare to experimental data showed excellent agreement for the angle of attacks examined, although failed to match the low speed experimental data at high sideslip angles

Outcomes of MYC-associated lymphomas after R-CHOP with and without consolidative autologous stem cell transplant: subset analysis of randomized trial intergroup SWOG S9704

Double hit lymphoma (DHL) and double protein-expressing (MYC and BCL2) lymphomas (DPL) fare poorly with R-CHOP; consolidative autologous stem cell transplant (ASCT) may improve outcomes. S9704, a phase III randomized study of CHOP +/−R with or without ASCT allows evaluation of intensive consolidation. Immunohistochemical analysis identified 27 of 198 patients (13.6%) with MYC IHC overexpression and 20 (74%) harboring concurrent BCL2 overexpression. Four had DHL and 16 had DPL only. With median follow-up 127 months, there is a trend favoring outcomes after consolidative ASCT in DPL and MYC protein overexpressing patients, whereas all DHL patients have died irrespective of ASCT

Comparison of electrical CD measurements and cross-section lattice-plane counts of sub-micrometer features replicated in Silicon-on-Insulator materials

Electrical test structures of the type known as cross-bridge resistors have been patterned in (100) epitaxial silicon material that was grown on Bonded and Etched-Back Silicon-on-Insulator (BESOI) substrates. The CDs (Critical Dimensions) of a selection of their reference segments have been measured electrically, by SEM (Scanning-Electron Microscopy) cross-section imaging, and by lattice-plane counting. The lattice-plane counting is performed on phase-contrast images made by High-Resolution Transmission-Electron Microscopy (HRTEM). The reference-segment features were aligned with <110> directions in the BESOI surface material. They were defined by a silicon micromachining process which results in their sidewalls being atomically-planar and smooth and inclined at 54.737{degree} to the surface (100) plane of the substrate. This (100) implementation may usefully complement the attributes of the previously-reported vertical-sidewall one for selected reference-material applications. The SEM, HRTEM, and electrical CD (ECD) linewidth measurements that are made on BESOI features of various drawn dimensions on the same substrate is being investigated to determine the feasibility of a CD traceability path that combines the low cost, robustness, and repeatability of the ECD technique and the absolute measurement of the HRTEM lattice-plane counting technique. Other novel aspects of the (100) SOI implementation that are reported here are the ECD test-structure architecture and the making of HRTEM lattice-plane counts from both cross-sectional, as well as top-down, imaging of the reference features. This paper describes the design details and the fabrication of the cross-bridge resistor test structure. The long-term goal is to develop a technique for the determination of the absolute dimensions of the trapezoidal cross-sections of the cross-bridge resistors reference segments, as a prelude to making them available for dimensional reference applications

Crop Updates 2003 - Cereals

This session covers twenty one papers from different authors: PLENARY 1. Recognising and responding to new market opportunities in the grains industry, Graham Crosbie, Manager, Grain Products Research, Crop Breeding, Plant Industries, Department of Agriculture 2. Stripe rust – where to now for the WA wheat industry? Robert Loughman1, Colin Wellings2 and Greg Shea11Department of Agriculture, 2University of Sydney Plant Breeding Institute, Cobbitty (on secondment from NSW Agriculture) 3. Benefits of a Grains Biosecurity Plan, Dr Simon McKirdy, Plant Health Australia, Mr Greg Shea, Department of Agriculture 4. Can we improve the drought tolerance of our crops? Neil C. Turner, CSIRO Plant Industry, Wembley 5. The silence of the lambing, Ross Kingwell, Department of Agriculture AGRONOMY AND VARIETIES 6. Maximising performance of wheat varieties, Brenda Shackley, Wal Anderson, Darshan Sharma, Mohammad Amjad, Steve Penny Jr, Melanie Kupsch, Anne Smith, Veronika Reck, Pam Burgess, Glenda Smith and Elizabeth Tierney, Department of Agriculture 7. Wheat variety performance in wet and dry, Peter Burgess 8. e-VarietyGuide for stripe rust – an updated version (1.02 – 2003), Moin Salam, Megan Collins, Art Diggle and Robert Loughman, Department of Agriculture 9. Baudin and Hamelin – new generation of malting barley developed in Western Australia, Blakely Paynter, Roslyn Jettner and Kevin Young, Department of Agriculture 10. Oaten hay production, Jocelyn Ball, Natasha Littlewood and Lucy Anderton, Department of Agriculture 11. Improving waterlogging tolerance in wheat and barley, Irene Waters and Tim Setter, Department of Agriculture 12. Broadscale variety comparisons featuring new wheat varieties, Jeff Russell, Department of Agriculture, Centre for Cropping Systems BIOTECHNOLOGY 13. Barley improvement in the Western Region – the intergration of biotechnologies, Reg Lance, Chengdao Li and Sue Broughton, Department of Agriculture 14. The Western Australian State Agricultural Biotechnology Centre – what we are and what we do, Michael Jones, WA State Agricultural Biotechnology Centre, Murdoch University 15. Protein and DNA methods for variety identification, Dr Grace Zawko, Saturn Biotech Limited 16. The Centre for High-throughput Agricultural Genetic Analysis (CHAGA), Keith Gregg, CHAGA, Murdoch University NUTRITION 17. Potassium – topdressed, drilled or banded? Stephen Loss, Patrick Gethin, Ryan Guthrie, Daniel Bell, Wesfarmers CSBP 18. Liquid phosphorus fertilisers in WA, Stephen Loss, Frank Ripper, Ryan Guthrie, Daniel Bell and Patrick Gethin, Wesfarmers CSBP 19. Wheat nutrition in the high rainfall cropping zone, Narelle Hill1and Laurence Carslake2, 1Department of Agriculture, 2Wesfarmers Landmark PESTS AND DISEASES 20. Managenent options for root lesion nematode in West Australian cropping systems, Vivien Vanstone, Sean Kelly and Helen Hunter, Department of Agriculture STORAGE 21. Aeration can profit your grain enterprise, Christopher R. Newman, Department of Agricultur