C.H. Skinner
A5025436098- Magnetic confinement fusion research
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Nuclear Materials and Properties
- Superconducting Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Plasma Diagnostics and Applications
- Ionosphere and magnetosphere dynamics
- Atomic and Molecular Physics
- Advanced X-ray Imaging Techniques
- Laser Design and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Muon and positron interactions and applications
- Ion-surface interactions and analysis
- Diamond and Carbon-based Materials Research
- Laser-Matter Interactions and Applications
- Laser-induced spectroscopy and plasma
- Graphite, nuclear technology, radiation studies
- Dust and Plasma Wave Phenomena
- Nuclear reactor physics and engineering
- Solar and Space Plasma Dynamics
- Photocathodes and Microchannel Plates
- Electron and X-Ray Spectroscopy Techniques
- Nuclear Physics and Applications
- Semiconductor materials and devices
Princeton Plasma Physics Laboratory
2014-2024
Natural Resources Canada
2023
Savannah River National Laboratory
2023
Princeton University
2002-2022
General Atomics (United States)
2006-2022
San Diego State University
2022
University of Illinois Urbana-Champaign
2022
Oak Ridge National Laboratory
1991-2017
Aix-Marseille Université
2010
University of Toronto
1999-2008
The major increase in discharge duration and plasma energy a next step DT fusion reactor will give rise to important plasma-material effects that critically influence its operation, safety performance. Erosion scale of several centimetres from being barely measurable at micron today's tokamaks. Tritium co-deposited with carbon strongly affect the operation machines facing components. Controlling plasma-wall interactions is critical achieving high performance present day tokamaks, this likely...
As part of the ITER Design Review and in response to issues identified by Science Technology Advisory Committee, physics requirements were reviewed as appropriate updated. The focus this paper will be on recent work affecting design with special emphasis topics near-term procurement arrangements. This describe results on: sensitivity studies, poloidal field coil requirements, vertical stability, effect toroidal ripple thermal confinement, material choice heat load for plasma-facing...
Dust production and accumulation present potential safety operational issues for the ITER. diagnostics can be divided into two groups: of dust on surfaces in plasma. Diagnostics from both groups are employed contemporary tokamaks; new suitable ITER also being developed tested. is likely to occur hidden areas, e.g., between tiles under divertor baffles. A novel electrostatic detector monitoring these regions has been tested at PPPL. In DIII-D tokamak include Mie scattering Nd:YAG lasers,...
Recent research in scrape-off layer (SOL) and divertor physics is reviewed; new existing data from a variety of experiments have been used to make cross-experiment comparisons with implications for further ITER. Studies the region near separatrix addressed relationship profiles turbulence as well scaling parallel power flow. Enhanced low-field side radial transport implicated driving flows inboard side. The medium-n nature edge localized modes (ELMs) has elucidated measurements determined...
National Spherical Torus Experiment [which M. Ono et al., Nucl. Fusion 40, 557 (2000)] high-power divertor plasma experiments have shown, for the first time, that benefits from lithium coatings applied to facing components found previously in limited plasmas can occur also diverted configurations. Lithium were with pellets injected into helium discharges, and an oven directed a collimated stream of vapor toward graphite tiles lower center stack divertor. depositions few milligrams 1g been...
Management of tritium inventory remains one the grand challenges in development fusion energy, and choice plasma-facing materials is a key factor for in-vessel retention. The Atomic Molecular Data Unit International Energy Agency organized Coordinated Research Project (CRP) on overall topic reactors during period 2001-2006. This dealt with hydrogenic retention ITER's – Be, C, W compounds (mixed materials) these elements as well removal techniques. results CRP are summarized this paper...
Abstract Lithium wall coatings have been shown to reduce recycling, suppress edge-localized modes (ELMs), and improve energy confinement in the National Spherical Torus Experiment (NSTX). Here we document effect of gradually increasing lithium on discharge characteristics, with reference ELMy discharges obtained boronized, i.e. non-lithiated conditions. We observed a continuous but not quite monotonic reduction recycling improvement confinement, gradual alteration edge plasma profiles,...
Research in NSTX has been conducted to establish spherical torus plasmas be used for high β, auxiliary heated experiments. This device a major radius R0 = 0.86 m and midplane halfwidth of 0.7 m. It operated with toroidal magnetic field B0 ⩽ 0.3 T Ip 1.0 MA. The evolution the plasma equilibrium is analysed between discharges an automated version EFIT code. Limiter, double null lower single diverted configurations have sustained several energy confinement times. stored reached 92 kJ (βt 17.8%)...
Wall conditioning in the Tokamak Fusion Test Reactor (TFTR) [K. M. McGuire et al., Phys. Plasmas 2, 2176 (1995)] by injection of lithium pellets into plasma has resulted large improvements deuterium–tritium fusion power production (up to 10.7 MW), Lawson triple product 1021 m−3 s keV), and energy confinement time 330 ms). The maximum current for access high-performance supershots been increased from 1.9 2.7 MA, leading stable operation at stored values greater than 5 MJ. amount on limiter...
Liquid metal plasma-facing components (PFCs) have been proposed as a means of solving several problems facing the creation economically viable fusion power reactors. To date, few demonstrations exist this approach in diverted tokamak and we here provide an overview such work on National Spherical Torus Experiment (NSTX). The Lithium Divertor (LLD) was installed operated for 2010 run campaign using evaporated coatings filling method. LLD consisted copper-backed structure with porous...
Lithium wall coatings have been shown to reduce recycling, improve energy confinement, and suppress edge localized modes in the National Spherical Torus Experiment. Here, we show that these effects depend continuously on amount of predischarge lithium evaporation. We observed a nearly monotonic reduction decrease electron transport, modification profiles stability with increasing lithium. These correlations challenge basic expectations, given even smallest exceeded needed for nominal...
The authors have observed an anomalous emission feature from a dense (\ensuremath{\sim} ${10}^{16}$ ${\mathrm{cm}}^{\ensuremath{-}3}$) barium vapor illuminated with ${\mathrm{N}}_{2}$ pumped dye laser (peak intensity \ensuremath{\sim} 1 MW ${\mathrm{cm}}^{\ensuremath{-}2}$). input wavelength was 552.5 nm, nm shorter in than the $6{s}^{2}^{1}S\ensuremath{-}6s6p^{1}P$ resonance transition. In forward direction strong emerging form of conical shell half-angle...
The National Spherical Torus Experiment (NSTX) has undergone a major upgrade, and the NSTX Upgrade (NSTX-U) Project was completed in summer of 2015.NSTX-U first plasma subsequently achieved, diagnostic control systems have been commissioned, H-mode accessed, magnetic error fields identified mitigated, physics research campaign carried out.During ten run weeks operation, NSTX-U surpassed record pulse-durations toroidal (TF), high-performance ~1 MA plasmas comparable to best sustained near...
Abstract An increased total energy was correlated with the addition of tritium were observed in supershots [1] during TFTR DT campaign [2] This regime had strikingly high, centrally peaked ion and electron temperatures, largest neutron emission rates TFTR. paper presents a study origin this increase stored energy. 

Twenty-six recently reanalyzed TRANSP plasma analysis code.Previous simulations did not accurately match measured magnitude time evolutions rates. mismatch is...
The Tokamak Fusion Test Reactor (TFTR) (R. J. Hawryluk, to be published in Rev. Mod. Phys.) experiments on high-temperature plasmas, that culminated the study of deuterium–tritium D–T plasmas containing significant populations energetic alpha particles, spanned over two decades from conception completion. During design TFTR, key physics issues were magnetohydrodynamic (MHD) equilibrium and stability, plasma energy transport, impurity effects, reactivity. Energetic particle was given less...
Global magnetohydrodynamic (MHD) stability limits in the National Spherical Torus Experiment (NSTX) have increased significantly recently due to a combination of device and operational improvements. First, more routine H-mode operation with broadened pressure profiles allows access higher normalized β lower internal inductance. Second, correction poloidal field coil induced error-field has largely eliminated locked tearing modes during normal maximum achievable β. As result these...
The emerging technology of soft x‐ray lasers is in a transition phase between the first laboratory demonstrations gain and acceptance as practical tools for novel applications. Current research focused on several fronts. operational wavelength range has been extended to ‘‘water window,’’ important applications life sciences. Gain also generated with substantially simpler (such 6 J laser) this augurs well commercial availability near future variety Advanced laser concepts are being developed...
It has been known for a long time that microscopic dust appears in plasmas fusion devices. Recently it was shown can be responsible the termination of long- discharges. Also, ITER-scale experiments pose safety problems related to its chemical activity, tritium retention and radioactive content. In particular, presence vacuum chamber ITER is one main concerns licensing process. Here we review recent progress understanding different experimental theoretical aspects physics dynamics transport...
The divergence of the C VI 182-\AA{} lasing line generated in a rapidly recombining, magnetically confined plasma column was measured with soft---x-ray spectrometers equipped multichannel detectors. In addition to measurements relative divergence, an absolute \ensuremath{\sim}9 mrad at magnetic field 20 kG and \ensuremath{\sim}5 35 or 50 obtained by direct scan axial radiation. Based on these data peak power \ensuremath{\sim}100 kW is obtained. Calculations spatial distribution gain were...
The urgent quest for new energy sources has led developed countries, representing over half of the world population, to collaborate on demonstrating scientific and technological feasibility magnetic fusion through construction operation international thermonuclear experimental reactor (ITER). Data high-Z ions will be important in this quest. Tungsten plasma facing components have necessary low erosion rates tritium retention but high radiative efficiency tungsten leads stringent restrictions...
Lithium wall conditioning has lowered hydrogenic recycling and dramatically improved plasma performance in many magnetic-fusion devices. In this Letter, we report quantum-classical atomistic simulations laboratory experiments that elucidate the roles of lithium oxygen uptake hydrogen amorphous carbon. Surprisingly, show creates a high concentration on carbon surface when bombarded by deuterium. Furthermore, oxygen, rather than lithium, plays key role trapping hydrogen.