A5088291381- Particle accelerators and beam dynamics
- Magnetic confinement fusion research
- Gyrotron and Vacuum Electronics Research
- Plasma Diagnostics and Applications
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Fusion materials and technologies
- Nuclear Physics and Applications
- Microwave Engineering and Waveguides
- Insect Pest Control Strategies
- Nuclear reactor physics and engineering
- Solar and Space Plasma Dynamics
- Carbon Nanotubes in Composites
- Electrostatic Discharge in Electronics
- Nuclear Materials and Properties
- HVDC Systems and Fault Protection
- Photonic and Optical Devices
- Ultrasonics and Acoustic Wave Propagation
- Muon and positron interactions and applications
- Semiconductor Lasers and Optical Devices
- Seismic Waves and Analysis
- Pulsed Power Technology Applications
- Fiber-reinforced polymer composites
- Advancements in Photolithography Techniques
- Chemical Synthesis and Characterization
Oak Ridge National Laboratory
2015-2024
University of North Dakota
2020
Theragenics Corporation (United States)
2003-2005
Futures Group (United States)
2005
Princeton Plasma Physics Laboratory
1993-2002
National Institute for Fusion Science
1996-2002
Fusion (United States)
2001
CompX (United States)
2001
Plasma Technology (United States)
2001
Fusion Academy
2001
A linearly polarized (LP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mn</sub> ) mode basis set for oversized, corrugated, metallic waveguides is derived the special case of quarter-wavelength-depth circumferential corrugations. The relationship between LP modes and conventional (HE , EH TE xmlns:xlink="http://www.w3.org/1999/xlink">0n</sub> TM corrugated guide shown. loss in a gap or equivalent miter bend waveguide calculated single-mode...
Linear plasma generators are cost effective facilities to simulate divertor conditions of present and future fusion reactors. They used address important R&D gaps in the science material interactions towards viable facing components for Next generation have be able access expected on targets ITER devices. The steady-state linear device MPEX will this regime with electron temperatures 1–10 eV densities . resulting heat fluxes about 10 MW is designed deliver those a novel Radio Frequency...
Plasma-facing materials in the divertor of a magnetic fusion reactor have to tolerate steady state plasma heat fluxes range 10 MW/m2 for ∼107 s, addition neutron fluences, which can damage plasma-facing high displacements per atom (dpa) ∼50 dpa. Materials solutions needed components are yet be developed and tested. The material exposure experiment (MPEX) is newly proposed linear device designed deliver necessary flux target testing, including capability expose priori neutron-damaged samples...
The ITER electron cyclotron heating (ECH) transmission lines (TLs) are 63.5-mm-diam corrugated waveguides that will each carry 1 MW of power at 170 GHz. TL is defined here as the waveguide system connecting gyrotron mirror optics unit (MOU) to entrance ECH launcher and includes miter bends other components. losses on have been calculated for four possible cases corresponding having HE11 mode purity input 100, 97, 90, 80%. due coupling, ohmic, conversion loss evaluated in detail using a...
Insect mortality studies were performed with a high-power microwave source operating at frequency of 10.6 GHz power levels 9–20 kW to irradiate samples soft white wheat, Triticum aestivum (L.), infested maize weevil, Sitophilus zeamais Motschulsky, and ground wheat red flour beetle, Tribolium castaneum (Herbst). These pests are common internal external feeders in stored products, respectively. Samples various age intervals from egg adult exposed. The results support the hypothesis that...
The Prototype Material Plasma Exposure eXperiment (Proto-MPEX) is being used to qualify the plasma source and heating systems for (MPEX). MPEX will address important urgent research needs on material interactions future fusion reactors. In MPEX, plasma-facing components (nonirradiated a priori neutron irradiated) be exposed conditions as they are expected in steady-state device enabled by superconducting magnets, able break into new ground assessing materials at an ion fluence level range of...
Abstract The Materials Plasma Exposure eXperiment (MPEX) is a steady-state linear plasma device that will address plasma-material interaction (PMI) science and enable testing of fusion reactor-relevant divertor plasma-facing materials. MPEX source concept consists helicon to generate the plasma, electron cyclotron heating (ECH) for heating, ion (ICH) heating. then transported axially PMI material target region test samples in conditions. This paper summarize physical technical basis MPEX....
The magnetic geometry of the Prototype Material Plasma Exposure eXperiment (Proto-MPEX) was recently modified to enable more effective utilization 28 GHz microwave auxiliary power, specifically: (1) heat plasma electrons in radial core device and (2) deliver heated target plate device. To achieve this goal, launcher placement were significantly re-engineered, guided by previous experimental results computational modeling. electron temperature region is observed increase from 3 eV 11 with 30...
The Material Plasma Exposure eXperiment (MPEX) has completed its design phase. MPEX will be a unique facility to investigate plasma material interactions (PMIs) under fusion prototypic divertor conditions in steady state. This includes exposure expected reactor divertor. Materials investigated include solids, liquids, and neutron pre-irradiated materials. Electron ion heating allow for large operational domain ranging from erosion-dominated PMI deposition-dominated conditions. An overview of...
A fourfold increase in the conversion of thermal electron Bernstein waves (EBW) to extraordinary mode (X mode) was measured when density scale length (Ln) progressively shortened by a local boron nitride limiter scrape-off an Ohmically heated National Spherical Torus Experiment plasma [M. Ono, S. Kaye, M. Peng et al., Proceedings 17th IAEA Fusion Energy Conference (IAEA, Vienna, 1999), Vol. 3, p. 1135]. The maximum efficiency approached 50% Ln reduced 0.7 cm, agreement with theoretical...
The availability of future fusion devices such as a Fusion Nuclear Science Facility (FNSF) or DEMO greatly depends on long operating lifetimes plasma facing components in their divertors. ORNL is designing the Material-Plasma Exposure eXperiment (MPEX), superconducting magnet, steady-state device to address material interactions reactors. MPEX will utilize new high-intensity source concept based RF technology. This allow experiment cover entire expected conditions divertor reactor. It be...
The Prototype Material Plasma Exposure eXperiment (Proto-MPEX) is a pulsed linear plasma device that uses radio frequency (RF) helicon antenna and ceramic window as the ionization source. Modeling performed within this work on operations predicts hot spots due to an RF-induced sheath. RF sheath potential leads physical sputtering of predominantly where sits around window. role oxygen in Proto-MPEX also investigated needed match experimental data. Experiments show reasonable agreement with...
Edge electron density profile measurements, including the scrape-off layer, have been made during ion cyclotron range of frequency (ICRF) heating with two-frequency differential-phase reflectometer installed on an ICRF antenna Tokamak fusion test reactor (TFTR). This system probes plasma using extraordinary mode two signals swept from 90 to 118 GHz, while maintaining a fixed-difference 125 MHz. The is used obtain profiles in 1×1011–3×1013 cm−3 high-field (4.5–4.9 T) full-size (R0=2.62 m,...
Reliably mitigating disruptions is essential for ITER to meet its long-term operational research plan without damage the in-vessel components. Currently, shattered pellet injection (SPI) technique most effective radiator of thermal energy and has been chosen baseline disruption mitigation system (DMS) ITER. The SPI process uses cryogenic temperatures desublimate material into barrel a pipe gun forming solid cylindrical pellet. Pellets will initially be hydrogen hydrogen–neon mixtures. Once...
Recent tests of infested, freely flowing, hard red wheat, in a 28GHz microwave applicator indicate that abounding energy input 56.8 J/g will produce mortality 99% for the least vulnerable species and agelevel each three major grain pests tested, i.e. Triticum aestivum (L.), infested withpupae, young larvae eggs rice weevil Sitophilus oryzae (L), flour beetle Triboliumcastaneum (Herbst), lesser borer Rhizopertha dominica (F.). A 200kW prototype unit is nowbeing developed testing at throughput...
This article presents the integration of a dose control circuit (DCC) with vertically aligned carbon nanofiber (VACNF) field emission devices through voltage boost up interface for implementation digital electrostatically focused e-beam array direct-write lithography concept. The VACNFs act as diodes high turn on (∼70V). Commercially available complementary metal-oxide-semiconductor technology is not capable handling such magnitude voltages. described in this offers an efficient technique to...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation N. Kobayashi, T. Bigelow, Bonicelli, S. Cirant, G. Denisov, R. Heidinger, M. Henderson, J.‐P. Hogge, B. Piosczyk, Ramponi, L. Rao, D. Rasmussen, Saibene, K. Sakamoto, Takahashi, J. Temkin, Thumm, Q. Tran, A. Verhoeven, H. Zohm; Design of Electron Cyclotron Heating Current Drive System ITER. AIP Conf. Proc. 28...