A5084282889- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Plasma Diagnostics and Applications
- Superconducting Materials and Applications
- Fusion materials and technologies
- Ionosphere and magnetosphere dynamics
- Gyrotron and Vacuum Electronics Research
- Laser-Plasma Interactions and Diagnostics
- Antenna Design and Analysis
- Microwave Engineering and Waveguides
- Electrostatic Discharge in Electronics
- Advanced Data Storage Technologies
- Nuclear Physics and Applications
- Particle Accelerators and Free-Electron Lasers
- Laser-induced spectroscopy and plasma
- Electromagnetic Launch and Propulsion Technology
- Dust and Plasma Wave Phenomena
- Spacecraft and Cryogenic Technologies
- Antenna Design and Optimization
- Geophysical Methods and Applications
- Nuclear reactor physics and engineering
- Metal and Thin Film Mechanics
- Physics of Superconductivity and Magnetism
- Muon and positron interactions and applications
- Electromagnetic Compatibility and Measurements
Oak Ridge National Laboratory
2015-2025
Princeton Plasma Physics Laboratory
2009-2024
Royal Military Academy
2020
University of Tennessee at Knoxville
2016-2018
University of Illinois Urbana-Champaign
2018
National Technical Information Service
2018
Office of Scientific and Technical Information
2018
Memorial University of Newfoundland
1994-2017
CEA Cadarache
2013
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2013
Plasma with significant central-cell beta can be sustained in a tandem mirror composed of three axisymmetric simple cells by the use ion-cyclotron resonant heating. Radial ponderomotive force due to rf electric field opposes centrifugal field-line curvature ensure interchange stability. This is indicated sensitive dependence plasma stability on sign difference between frequency and frequency.
The availability of future fusion devices, such as a nuclear science facility or demonstration power station, 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 highintensity source concept based RF technology. This allow experiment cover entire expected conditions divertor reactor....
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...
The ability to obtain high plasma densities with fractional ionization using readily available, low-cost components makes the helicon a candidate source for many applications, including rocket propulsion, fusion component testing, and materials processing. However, operation of can be sensitive function magnetic field strength geometry as well driving frequency, especially when light feedstock gases such hydrogen or helium. In this paper, results from coupled rf transport model are compared...
AbstractA new era of fusion research has started with ITER being constructed and DEMO for power demonstration on the horizon. However, nuclear science needs to be developed before can designed. One most crucial complex outstanding issues solved is plasma surface interaction (PSI) in hostile environment a reactor. Not only are materials exposed unprecedented steady-state transient fluxes, but they also neutron fluxes. Both ion fluxes will change micro-structure facing significantly even...
This paper summarizes the operational experience of ion cyclotron resonant frequency (ICRF) ITER-like antenna on JET aiming at substantially increasing power density in range requirements for ITER combined with load resiliency. An in-depth description its commissioning, aspects and achieved performances is presented.
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...
Proto-MPEX is a linear plasma device being used to study novel RF source concept for the planned Material Plasma Exposure eXperiment (MPEX), which will address plasma-materials interaction (PMI) nuclear fusion reactors. Plasmas are produced using large diameter helicon operating at frequency of 13.56 MHz power levels up 120 kW. In recent experiments has deuterium plasmas with densities ~6 × 1019 m–3 measured location 2 m downstream from antenna and 0.4 target. Previous production on have...
The Prototype-Material Plasma Exposure eXperiment (Proto-MPEX) linear plasma device is a test bed for exploring and developing source concepts to be employed in the future steady-state Material (MPEX) that will study plasma-material interactions nuclear fusion program. concept foresees using helicon supplemented with electron ion heating systems reach necessary conditions. In this paper, we discuss temperature measurements obtained from Doppler broadening of spectral lines argon particles....
Abstract Radio-frequency (RF) driven helicon plasma sources can produce relatively high-density plasmas ( n > 10 19 m −3 ) at moderate powers (<2 kW) in argon. However, to similar for fusion relevant gases such as hydrogen (H), deuterium (D) and helium (He), much higher RF are needed. For very high powers, thermal issues of the RF-transparent dielectric window, used source design, limit operation timescales. To mitigate this constraint, we have designed, built tested a novel assembly...
The paper summarizes the continuous developments made to ion cyclotron resonant frequency (ICRF) system at JET in order improve reliability of power coupled plasma. It details changes and improvements so that more is during ELMy plasmas as well increasing density demonstrate reliable operation range requirements for ITER. Results obtained using conventional matching (stubs trombones) system, 3 dB couplers conjugate-T scheme with variable elements outside wave launching structure (external...
The Proto-MPEX helicon source has been operating in a high electron density 'helicon-mode'. Establishing plasma densities and magnetic field strengths under the antenna that allow for formation of normal modes fast-wave are believed to be responsible A 2D finite-element full-wave model on is used identify steady-state profile produced by source. We also show through simulation regions operation which core power deposition maximum slow-wave does not deposit significant besides directly...
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...
The Material Plasma Exposure eXperiment (MPEX) is a steady state linear device with the goal to perform plasma material interaction (PMI) studies at future fusion reactor relevant conditions. A prototype of MPEX referred as Porto-MPEX designed carry out research and development related source, heating transport concepts on planned full device. auxiliary schemes in are based cyclotron resonance radio frequency (RF) waves. Ion (ICH) electron (ECH) used independently heat ions electrons provide...
The steady-state linear device “Material Plasma Exposure eXperiment” (MPEX) is currently under construction at Oak Ridge National Laboratory with the goal of enabling Plasma-Material Interaction studies future fusion reactor relevant plasma conditions. In this work, a newly in-house developed hybrid Particle-In-Cell code-PICOS++ applied to understand experimental results obtained from prototype MPEX referred as “Proto-MPEX” during its helicon-only and helicon ion cyclotron resonance heating...
The non-inductive current drive from directional fast Alfven and electron cyclotron waves was measured in the DIII-D tokamak order to demonstrate these forms of radiofrequency (RF) compare efficiencies with theoretical expectations. wave frequency 8 times deuterium at plasma centre, while twice frequency. Complete achieved using a combination (FWCD) (ECCD) discharges for which total inductively ramped down 400 170 kA. For steady discharges, an analysis loop voltage revealed up 195 kA (out...
The development of the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) was initiated in late 1970s to address a critical requirement for fast, high-power interplanetary space transportation. While not being fusion rocket, it nevertheless borrows heavily from that technology and takes advantage natural topology open-ended magnetic systems. In addition its high power density exhaust velocity, VASIMR is capable constant throttling feature, which allows in-flight mission-optimization...
A high density (1019 m−3) hydrogen plasma has been sustained successfully in axially non-uniform static magnetic field configurations for frequencies both above and below the limit of lower hybrid resonance frequency (LH-HD). Wave measurements suggest several modes are coupling to generate these helicon plasmas. The dependence on strength a fixed geometry can be explained by waves, with wavelength close antenna length, that couple fundamental radial mode LH-HD second frequency.
The Prototype Material Plasma Exposure eXperiment (Proto-MPEX) at Oak Ridge National Laboratory (ORNL) is a precursor linear plasma device to the (MPEX), which will study material interactions (PMIs) for future fusion reactors. This paper discuss initial steps performed towards completing power balance on Proto-MPEX quantify where energy lost from plasma, including relevant diagnostic package implemented. Machine operating parameters that improve Proto-MPEX’s performance may be identified,...
We present time-resolved measurements of an edge-to-core power transition in a light-ion (deuterium) helicon discharge the form infra-red camera imaging thin stainless steel target plate on Proto-Material Exposure eXperiment device. The images measure two-dimensional distribution deposition discharge. displays mode characterized by significant increase on-axis electron density and core coupling, suppression edge formation fast-wave radial eigenmode. Although self-consistent mechanism that...
The Materials Plasma Exposure eXperiment (MPEX) is a linear plasma device that will address the plasma-material interaction (PMI) science for future fusion reactors and enable testing of plasma-facing components (PFCs). It designed as steady-state eventually delivering an ion fluence up to 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">31</sup> m xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> target. be handle neutron-activated...