A5057000822- Magnetic confinement fusion research
- Plasma Diagnostics and Applications
- Particle accelerators and beam dynamics
- Fusion materials and technologies
- Ionosphere and magnetosphere dynamics
- Laser-induced spectroscopy and plasma
- Laser-Plasma Interactions and Diagnostics
- Dust and Plasma Wave Phenomena
- Superconducting Materials and Applications
- Particle Accelerators and Free-Electron Lasers
- Magnetic Field Sensors Techniques
- Muon and positron interactions and applications
- Radiation Effects in Electronics
- Antenna Design and Analysis
- Metal and Thin Film Mechanics
- Atomic and Molecular Physics
- Solar and Space Plasma Dynamics
- Spacecraft and Cryogenic Technologies
- Advanced Sensor Technologies Research
- Graphite, nuclear technology, radiation studies
- High voltage insulation and dielectric phenomena
- Electrostatic Discharge in Electronics
- Plasma Applications and Diagnostics
- Energy Harvesting in Wireless Networks
- Theoretical and Computational Physics
Oak Ridge National Laboratory
2016-2024
CompX (United States)
2022-2023
University of Tennessee at Knoxville
2018
University of Illinois Urbana-Champaign
2017-2018
Australian National University
2012-2017
The Magnetized Plasma Interaction Experiment (MAGPIE) is a versatile helicon source plasma device operating in magnetic hill configuration designed to support broad range of research activity and the first stage Materials Diagnostic Facility at Australian National University. Various material targets can be introduced study plasma–material interaction phenomena.
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...
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...
A radio frequency field solver based on Maxwell's equations and a cold plasma dielectric tensor is employed to describe wave phenomena observed in cylindrical non-uniform helicon discharge. The experiment carried out recently built linear plasma-material interaction machine: magnetized [Blackwell et al., Plasma Sources Sci. Technol. (submitted)], which both density static magnetic are functions of axial position. strength increases by factor 15 from source target plate, the electron...
An analytical model describing the physics of driven floating probes has been developed to RF compensation double langmuir probe (DLP) technique. The is based on theory self-bias effect as described in Braithwaite's work [1], which we extend include time-resolved behaviour. main contribution this allow quantitative determination intrinsic a DLP given discharge. Using these ideas, discuss design compensated DLPs. Experimental validation for ideas presented and effects rectification...
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....
Antenna radiation patterns in the vicinity of a helicon antenna are investigated hydrogen plasmas produced MAGPIE linear plasma device. Using uniform cold-plasma full-wave code, we model wave physics and find good agreement with experimental measurements. We show for first time which elements device couple most strongly to discuss physical mechanism that determines this effect. Helicon wavefields near field best described terms group velocity ray direction, while far from antenna, behave...
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...
In this paper, we investigate the propagation and damping of helicon waves along length (50 cm) a helicon-produced 20 kW hydrogen plasma ( 1–2 1019 m−3, 1–6 eV, H2 8 mTorr) operated in magnetic mirror configuration (antenna region: 50–200 G 800 G). Experimental results show presence traveling (4–8 10–15 propagating away from antenna region which become collisionally absorbed within 40–50 cm. We describe use WKB method to calculate wave provide an expression assess its validity based on...
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 Prototype Material Plasma Exposure Experiment at the Oak Ridge National Laboratory utilizes a variety of power systems to generate and deliver high heat flux plasma onto surface material targets. In experiments described here, deuterium is produced via ∼100 kW, 13.56 MHz RF helicon source, which ∼20 kW 28 GHz microwave applied. electron density temperature profiles are measured using Thomson scattering (TS) diagnostic, indicate that centrally peaked. core column, higher than cut-off...
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...
High density (≥6 × 1019 m−3), low temperature (2–6 eV) helicon discharges in the Prototype Material Plasma Exposure eXperiment (Proto-MPEX) are analyzed with coupled multifluid plasma, kinetic neutrals code B2.5-Eirene. The interpretative analyses constrained by data from multiple diagnostics, including Langmuir probes, Mach filterscopes, infrared TV system, Thomson scattering, and baratrons. objectives of transport simulations include: investigation effects heating, fueling, plasma...
The physics of electron and ion heating high-density deuterium helicon plasmas (&gt;3 × 1019 m−3) in the Proto-Material Plasma Exposure Experiment linear device are under investigation. Theoretical estimates indicate that for efficient heating, discharges with very low neutral gas content (≪0.1 Pa) sections required to minimize collisional losses charge exchange interactions neutrals. However, this requirement is typically not compatible pressures (1–2 commonly used high-density,...
Ion cyclotron heating (ICH) on the Prototype Material Plasma Exposure eXperiment (Proto-MPEX) is to be accomplished using “beach-heating” technique. Beach has not been previously demonstrated efficiently heat core ions at high electron density values present in Proto-MPEX. This work numerically investigates wave propagation characteristics of ICH region Proto-MPEX explore avenues for efficient ion heating. The analysis reveals that finite temperature effects are required predict Cold plasma...
The light-ion helicon plasma source of the Proto-MPEX linear device has been recently upgraded to enable pulsed (0.5–1 s) operation up 200 kW. main objective this work is report on plasma-induced surface heat fluxes incident window during high power (60–150 kW net power) for purpose design upcoming material exposure eXperiment (MPEX). IR imaging system and associated physics models extraction are presented. Experimental results demonstrate that control strike point via magnetic flux mapping...
The physics of ion cyclotron heating (ICH) relevant to the steady-state linear machine MPEX (Material Plasma Exposure eXperiment) has been explored in its predecessor, short-pulse device: Proto-MPEX. will utilize fundamental ICH increase heat flux at target and produce temperatures velocity distributions with improved fidelity those found a tokamak divertor region, comparison produced by substrate biasing. In experiments on Proto-MPEX described here, bulk up ∼ 15 eV have achieved 20 kW net...