A5036716187- Magnetic confinement fusion research
- Plasma Diagnostics and Applications
- Laser-induced spectroscopy and plasma
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Fusion materials and technologies
- Spectroscopy and Laser Applications
- Atomic and Molecular Physics
- Ion-surface interactions and analysis
- Integrated Circuits and Semiconductor Failure Analysis
- Electromagnetic Compatibility and Measurements
- Electron and X-Ray Spectroscopy Techniques
- Particle Accelerators and Free-Electron Lasers
- CCD and CMOS Imaging Sensors
- Image Processing Techniques and Applications
- Laser-Plasma Interactions and Diagnostics
- Electrostatic Discharge in Electronics
- Magnetic Properties and Applications
- Advanced Semiconductor Detectors and Materials
- High voltage insulation and dielectric phenomena
- Power Transformer Diagnostics and Insulation
- Dust and Plasma Wave Phenomena
- Nuclear Materials and Properties
- Advanced Optical Sensing Technologies
Oak Ridge National Laboratory
2016-2025
Michigan State University
2025
University of Michigan–Ann Arbor
2025
National Technical Information Service
2018
Office of Scientific and Technical Information
2018
Aker Arctic (Canada)
2016
CEA Cadarache
2015
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2015
North Carolina State University
2005-2014
Universidad de Murcia
2002
Samples of commercial plastics have been bombarded by short pulses nonpenetrating electrons. Observations charge transients representing the long-lived component induced current lead to following conclusions: (i) One carrier species is rapidly and strongly localized; (ii) mobile excess carriers decay bimolecular recombination; (iii) although such cannot in practice complete transits through thickness samples, they can be swept out excited layer into electrode. This paper fully explains how...
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...
This work presents the assembly of 48 papers, representing 74 different compounds and blends, into a machine-readable database nonaqueous proton-conducting materials. SMILES was used to encode chemical structures molecules, we tabulated reported proton conductivity, diffusion coefficient, material composition for total 3152 data points. The spans broad range temperatures ranging from −70 260 °C. To explore this landscape conductors, DFT calculate affinity 18 unique carriers. results were...
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 electrical conduction in a number of commercial plastics has been studied under pulsed bombardment by fully penetrating electrons. Detailed results are given mainly for polystyrene. kinetics obeyed the ``prompt'' component induced current predominantly first order, those ``long-lived'' current, second order. generally support assumptions made Paper I, and particular confirm interpretation decay time long-lived as bimolecular recombination lifetime. A simple model radiation-induced...
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....
Three identical new WEST Ion Cyclotron Resonance Heating (ICRH) antennas have been designed, assembled then commissioned on plasma from 2013 to 2019.The ICRH system is both load-resilient and compatible with long-pulse operations.The three successfully operated together in 2019 2020.The load resilience capability has demonstrated the antenna feedback controls for phase matching developed.The breakdown detection systems validated protected antennas.The use of combination Lower Hybrid...
Helicon current drive (CD), also called fast wave CD in the lower hybrid range of frequencies, has long been regarded as a promising tool for reactor grade plasmas.A newly installed MW-level system at DIII-D will be first test this technology reactor-relevant plasmas, sense that full single-pass absorption is expected.A 30-module traveling antenna and optimized in-vessel early 2020.The linear electromagnetic characteristics unloaded module array have extensively tested both on bench vessel...
Abstract High power experiments, up to 9.2 MW with LHCD and ICRH, have been carried out in the full tungsten tokamak WEST. Quasi non inductive discharges achieved allowing extend plasma duration 53 s stationary conditions particular respect contamination. Transitions H mode are observed, H-modes lasting 4 obtained. The increase stored energy is weak since crossing separatrix close L–H threshold. Hot L plasmas (central temperature exceeding 3 keV) a confinement time following ITER L96 scaling...
Novel experimental measurements of the lower hybrid (LH) wave electric field vector, ELH, obtained in Alcator C-Mod using dynamic Stark spectroscopy are presented. Three key results were by comparison with 3D full-wave COMSOL simulations cold plasma dielectric tensor and reflectometry-measured density profiles. (1) As a function space LH power, magnitude ELH was found to agree simulation result. (2) The direction have substantial poloidal component is strong disagreement nearly radial (3)...
Fully dynamic Stark effect visible spectroscopy was used for the first time to directly measure local rf electric field in boundary plasma near a high-power antenna high-performance, magnetically confined, fusion energy experiment. The measurement performed superconducting tokamak Tore Supra, of 1–3 MW, lower-hybrid, 3.7 GHz wave-launch antenna, and combined with modeling neutral atom transport estimate amplitude (as low as 1–2 kV/cm) direction this region. then shown be consistent predicted...
Doppler-free saturation spectroscopy provides a very powerful method to obtain detailed information about the electronic structure of atom through measurement spectral line profile. This is achieved significant decrease in Doppler broadening and essentially an elimination instrument inherent passive spectroscopic techniques. In this paper we present technique associated physics addition how one selects appropriate transition. Simulations Hδ spectra are presented illustrate increased...
Abstract More than 0.6 MW of rf power at 476 MHz has been coupled to DIII-D plasmas by launching helicon (whistler) waves with a traveling-wave antenna (comb-line) in the fast-wave polarization (Van Compernolle et al 2021 Nucl. Fusion 61 116034) which resulted observation electron heating core plasma single-pass absorption based on ray-tracing L-mode discharges. The coupling performance 1.5 m wide 30-element comb-line consistent expectations 2015–2016 experiments low-power 12-element...
Interaction of radio-frequency (RF) waves with the plasma in near-field a high-power wave launcher is now seen to be an important topic, both understanding channeling these through boundary and avoiding power losses edge. In recent Letter, direct non-intrusive measurement near antenna RF electric field range lower hybrid (LH) frequencies (ELH) was announced (2013 Phys. Rev. Lett. 110 215005). This achieved fitting Balmer series deuterium spectral lines utilizing time dependent (dynamic)...
Abstract Helicon waves have been recently proposed as an off-axis current drive actuator due to their expected high efficiency in the mid-radius region beta tokamaks. This paper focuses on a numerical study better understand effects of scrape-off-layer (SOL) turbulence helicon wave propagation and absorption DIII-D tokamak using developed full-wave model with turbulent density inputs from synthetic single wavelength SOL first-principles HERMES multi-wavelength models. With both input models,...
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...
Passive spectroscopic measurements of Zeeman splitting have been used reliably to measure magnetic fields in plasmas for decades. However, a requirement is that the field magnitude must be sufficiently strong resolved over Doppler and instrument broadening (typically >10 000 G). A diagnostic measuring spectroscopically well below this limit (>20 G) with high sensitivity has developed at Oak Ridge National Laboratory. The relies on resolution spectral profile using Doppler-free...