349 results on '"Nicolas JC"'
Search Results
2. A Lived Experience Co-Designed Study Protocol for a Randomised Control Trial: The Attempted Suicide Short Intervention Program (ASSIP) or Brief Cognitive Behavioural Therapy as Additional Interventions After a Suicide Attempt Compared to a Standard Suicide Prevention Pathway (SPP).
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Stapelberg, Nicolas JC, primary, Bowman, Candice, additional, Woerwag-Mehta, Sabine, additional, Walker, Sarah, additional, Davis, Angela, additional, Hughes, Ian, additional, Michel, Konrad, additional, Pisani, Anthony R, additional, Engelen, Heidy Van, additional, Delos, Mia, additional, Hageman, Tamara, additional, Fullerton-Smith, Kim, additional, Krishnaiah, Ravikumar, additional, McDowell, Sarah, additional, Cameron, Alison, additional, Scales, Trudy-Lee, additional, Dillon, Cherie, additional, Gigante, Titta, additional, Heddle, Cindy, additional, Mudge, Natalie, additional, Zappa, Anne, additional, Edwards, Michelle, additional, Gutjahr, Sigrun, additional, Joshi, Hitesh, additional, and Turner, Kathyrn, additional
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- 2021
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3. Reduced suicidal presentations to emergency departments during the COVID‐19 outbreak in Queensland, Australia
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Sveticic, Jerneja, primary, Stapelberg, Nicolas JC, additional, and Turner, Kathryn, additional
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- 2021
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4. Suicide prevention during COVID-19: identification of groups with reduced presentations to emergency departments
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Sveticic, Jerneja, primary, Stapelberg, Nicolas JC, additional, and Turner, Kathryn, additional
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- 2021
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5. Implementing a systems approach to suicide prevention in a mental health service using the Zero Suicide Framework
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Turner, Kathryn, primary, Sveticic, Jerneja, additional, Almeida-Crasto, Alice, additional, Gaee-Atefi, Taralina, additional, Green, Vicki, additional, Grice, Diana, additional, Kelly, Petra, additional, Krishnaiah, Ravikumar, additional, Lindsay, Luke, additional, Mayahle, Brian, additional, Patist, Carla, additional, Van Engelen, Heidy, additional, Walker, Sarah, additional, Welch, Matthew, additional, Woerwag-Mehta, Sabine, additional, and Stapelberg, Nicolas JC, additional
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- 2020
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6. Inconvenient truths in suicide prevention: Why a Restorative Just Culture should be implemented alongside a Zero Suicide Framework
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Turner, Kathryn, primary, Stapelberg, Nicolas JC, additional, Sveticic, Jerneja, additional, and Dekker, Sidney WA, additional
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- 2020
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7. Mitigation of divertor heat flux by high-frequency ELM pacing with non-fuel pellet injection in DIII-D
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T.H. Osborne, A. Nagy, Larry R. Baylor, Nicolas Jc Commaux, Robert Lunsford, R. Maingi, Raffi Nazikian, A. L. Roquemore, D.K. Mansfield, Daisuke Shiraki, Alessandro Bortolon, C.J. Lasnier, G.L. Jackson, and M.J. Makowski
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Nuclear and High Energy Physics ,Toroid ,Materials science ,DIII-D ,Field line ,Materials Science (miscellaneous) ,Divertor ,Granule (cell biology) ,Pellets ,Mechanics ,01 natural sciences ,lcsh:TK9001-9401 ,010305 fluids & plasmas ,Pedestal ,Nuclear Energy and Engineering ,Heat flux ,0103 physical sciences ,lcsh:Nuclear engineering. Atomic power ,Atomic physics ,010306 general physics - Abstract
Experiments have been conducted on DIII-D investigating high repetition rate injection of non-fuel pellets as a tool for pacing Edge Localized Modes (ELMs) and mitigating their transient divertor heat loads. Effective ELM pacing was obtained with injection of Li granules in different H-mode scenarios, at frequencies 3–5 times larger than the natural ELM frequency, with subsequent reduction of strike-point heat flux (Bortolon et al., Nucl. Fus., 56, 056008, 2016). However, in scenarios with high pedestal density (∼6 × 1019 m−3), the magnitude of granule triggered ELMs shows a broad distribution, in terms of stored energy loss and peak heat flux, challenging the effectiveness of ELM mitigation. Furthermore, transient heat-flux deposition correlated with granule injections was observed far from the strike-points. Field line tracing suggest this phenomenon to be consistent with particle loss into the mid-plane far scrape-off layer, at toroidal location of the granule injection.
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- 2017
8. Design and Commissioning of a Three-Barrel Shattered Pellet Injector for DIII-D Disruption Mitigation Studies
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T. Ha, W. D. McGinnis, S.K. Combs, Larry R. Baylor, Daisuke Shiraki, Nicolas Jc Commaux, T. Bjorholm, and Steven J. Meitner
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010302 applied physics ,Nuclear and High Energy Physics ,Tokamak ,Materials science ,DIII-D ,Mechanical Engineering ,Nuclear engineering ,Barrel (horology) ,Injector ,Plasma ,01 natural sciences ,010305 fluids & plasmas ,law.invention ,Nuclear Energy and Engineering ,Runaway electrons ,law ,0103 physical sciences ,Pellet ,General Materials Science ,Civil and Structural Engineering - Abstract
Disruptions are sudden unplanned terminations of tokamak plasmas that can lead to high thermal loads and runaway electrons (REs). Unmitigated disruptions in ITER are predicted to dissipate ...
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- 2017
9. Core tungsten radiation diagnostic calibration by small shell pellet injection in the DIII-D tokamak
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Nicolas Jc Commaux, Neil Alexander, Igor Bykov, Daniel Thomas, Daisuke Shiraki, Auna Moser, Eric Hollmann, and Brian Victor
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Brightness ,Tokamak ,Materials science ,DIII-D ,business.industry ,Pellets ,chemistry.chemical_element ,Radiation ,Tungsten ,01 natural sciences ,010305 fluids & plasmas ,law.invention ,Core (optical fiber) ,Optics ,chemistry ,law ,0103 physical sciences ,Plasma diagnostics ,Atomic physics ,010306 general physics ,business ,Instrumentation - Abstract
Injection of small (outer diameter = 0.8 mm) plastic pellets carrying embedded smaller (10 μg) tungsten grains is used to check calibrations of core tungsten line radiation diagnostics in support of the 2016 tungsten ring campaign in the DIII-D tokamak. Observed total brightness (1 eV–10 keV) and soft x-ray (1 keV–10 keV) brightness are found to be reasonably well (
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- 2017
10. ELM mitigation with pellet ELM triggering and implications for PFCs and plasma performance in ITER
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Larry R. Baylor, A. Loarte, S.L. Allen, Tom Osborne, G. T. A. Huijsmans, Anthony Leonard, S. Maruyama, Nicolas Jc Commaux, R.A. Moyer, Peter Lang, Charles Lasnier, Todd Evans, T.C. Jernigan, R. Maingi, Steven J. Meitner, Max E. Fenstermacher, S.K. Combs, Science and Technology of Nuclear Fusion, and Magneto-Hydro-Dynamic Stability of Fusion Plasmas
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Nuclear and High Energy Physics ,Materials science ,DIII-D ,Nuclear engineering ,Divertor ,digestive, oral, and skin physiology ,Pellets ,Plasma ,Ballooning ,Nuclear physics ,Materials Science(all) ,Nuclear Energy and Engineering ,ASDEX Upgrade ,Heat flux ,Pellet ,General Materials Science - Abstract
PLASMA-SURFACE INTERACTIONS 21 — Proceedings of the 21st International Conference on Plasma-Surface Interactions in Controlled Fusion Devices Kanazawa, Japan May 26-30, 2014 The triggering of rapid small edge localized modes (ELMs) by high frequency pellet injection has been proposed as a method to prevent large naturally occurring ELMs that can erode the ITER plasma facing components (PFCs). Deuterium pellet injection has been used to successfully demonstrate the ondemand triggering of edge localized modes (ELMs) at much higher rates and with much smaller intensity than natural ELMs. The proposed hypothesis for the triggering mechanism of ELMs by pellets is the local pressure perturbation resulting from reheating of the pellet cloud that can exceed the local high-n ballooning mode threshold where the pellet is injected. Nonlinear MHD simulations of the pellet ELM triggering show destabilization of high-n ballooning modes by such a local pressure perturbation. A review of the recent pellet ELM triggering results from ASDEX Upgrade (AUG), DIII-D, and JET reveals that a number of uncertainties about this ELM mitigation technique still remain. These include the heat flux impact pattern on the divertor and wall from pellet triggered and natural ELMs, the necessary pellet size and injection location to reliably trigger ELMs, and the level of fueling to be expected from ELM triggering pellets and synergy with larger fueling pellets. The implications of these issues for pellet ELM mitigation in ITER and its impact on the PFCs are presented along with the design features of the pellet injection system for ITER. 2014 Elsevier B.V. All rights reserved. 1. Introduction The H-mode confinement regime of plasma operation is planned for ITER in order to achieve high fusion performance. It is characterized by a steep pressure gradient and ‘‘pedestal’’ at the plasma edge that is expected to lead to the quasi-periodic instability of edgelocalized modes (ELMs) [1]. ELMs expel periodic bursts of particles and energy from the plasma, which if large enough can pose a serious threat to the PFCs by erosion and melting from the high heat fluxes and
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- 2015
11. Implementing a systems approach to suicide prevention in a mental health service using the Zero Suicide Framework.
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Turner, Kathryn, Sveticic, Jerneja, Almeida-Crasto, Alice, Gaee-Atefi, Taralina, Green, Vicki, Grice, Diana, Kelly, Petra, Krishnaiah, Ravikumar, Lindsay, Luke, Mayahle, Brian, Patist, Carla, Van Engelen, Heidy, Walker, Sarah, Welch, Matthew, Woerwag-Mehta, Sabine, and Stapelberg, Nicolas JC
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SUICIDE prevention ,MEDICAL care ,MACHINE learning ,CONCEPTUAL structures ,HUMAN services programs ,SYSTEM analysis ,QUALITY assurance ,MENTAL health services - Abstract
Objective: The Zero Suicide Framework, a systems approach to suicide prevention within a health service, is being implemented across a number of states in Australia, and internationally, although there is limited published evidence for its effectiveness. This paper aims to provide a description of the implementation process within a large health service in Australia and describes some of the outcomes to date and learnings from this process. Method: Gold Coast Mental Health and Specialist Services has undertaken an implementation of the Zero Suicide Framework commencing in late 2015, aiming for high fidelity to the seven key elements. This paper describes the practical steps undertaken by the service, the new practices embedded, emphasis on supporting staff following the principles of restorative just culture and the development of an evaluation framework to support a continuous quality improvement approach. Results: Improvements have been demonstrated in terms of processes implementation, enhanced staff skills and confidence, positive cultural change and innovations in areas such as the use of machine learning for identification of suicide presentations. A change to 'business as usual' has benefited thousands of consumers since the implementation of a Suicide Prevention Pathway in late 2016 and achieved reductions in rates of repeated suicide attempts and deaths by suicide in Gold Coast Mental Health and Specialist Services consumers. Conclusion: An all-of-service, systems approach to suicide prevention with a strong focus on cultural shifts and aspirational goals can be successfully implemented within a mental health service with only modest additional resources when supported by engaged leadership across the organisation. A continuous quality improvement approach is vital in the relentless pursuit of zero suicides in healthcare. [ABSTRACT FROM AUTHOR]
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- 2021
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12. Study of Z scaling of runaway electron plateau final loss energy deposition into wall of DIII-D
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D.L. Rudakov, Nicolas Jc Commaux, Jose Ramon Martin-Solis, C. M. Cooper, Charles Lasnier, Carlos Paz-Soldan, Paul Parks, Daisuke Shiraki, Eric Hollmann, N.W. Eidietis, and Ministerio de Economía y Competitividad (España)
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Hard X-rays ,X-ray fluorescence ,Circuit theorems ,Electron ,Kinetic energy ,01 natural sciences ,010305 fluids & plasmas ,Ion ,Runaway electrons ,Plasma impurities ,Impurity ,Electrical resistivity and conductivity ,0103 physical sciences ,Thermodynamic states and processes ,010306 general physics ,Physics ,Física ,Plasma ,Condensed Matter Physics ,Cameras ,Energy conversion ,Thermography ,Atomic physics ,Joule heating ,Deposition (chemistry) ,Tokamaks - Abstract
Controlled runaway electron (RE) plateau-wall strikes with different initial impurity levels are used to study the effect of background plasma ion charge Z (resistivity) on RE-wall loss dynamics. It is found that Joule heating (magnetic to kinetic energy conversion) during the final loss does not go up monotonically with increasing Z but peaks at intermediate Z similar to 6. Joule heating and overall time scales of the RE final loss are found to be reasonably well-described by a basic 0D coupled-circuit model, with only the loss time as a free parameter. This loss time is found to be fairly well correlated with the avalanche time, possibly suggesting that the RE final loss rate is limited by the avalanche rate. First attempts at measuring total energy deposition to the vessel walls by REs during the final loss are made. At higher plasma impurity levels Z > 5, energy deposition to the wall appears to be consistent with modeling, at least within the large uncertainties of the measurement. At low impurity levels Z < 5, however, local energy deposition appears around 5-20x less than expected, suggesting that the RE energy dissipation at low Z is not fully understood. Published by AIP Publishing. This work was supported in part by the U.S. Department of Energy under Nos. DE-FG02-07ER54917, DE-FC02-04ER54698, DE-AC05-00OR22725, DE-AC52-07NA27344, and DE-AC05-06OR23100 and in part by the Spanish Direccion General de Investigacion Cientifica y Tecnica under Projects ENE2012–31753 and ENE2015-66444R (MINECO/FEDERE, UE). DIII-D data shown in this paper can be obtained in digital format by following the links at https://fusion.gat.com/global/D3D_DMP Publicado
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- 2017
13. Applying the new gamma ray imager diagnostic to measurements of runaway electron Bremsstrahlung radiation in the DIII-D Tokamak (invited)
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Daisuke Shiraki, Carlos Paz-Soldan, Eric Hollmann, C. M. Cooper, David Pace, Nicolas Jc Commaux, and N.W. Eidietis
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Physics ,Scintillation ,DIII-D ,business.industry ,Gamma ray ,Bremsstrahlung ,01 natural sciences ,Particle detector ,010305 fluids & plasmas ,law.invention ,Optics ,law ,0103 physical sciences ,Scintillation counter ,Pinhole camera ,Plasma diagnostics ,010306 general physics ,business ,Instrumentation - Abstract
A new gamma ray imager (GRI) is developed to probe the electron distribution function with 2D spatial resolution during runaway electron (RE) experiments at the DIII-D tokamak. The diagnostic is sensitive to 0.5-100 MeV gamma rays, allowing characterization of the RE distribution function evolution during RE growth and dissipation. The GRI consists of a lead "pinhole camera" mounted on the DIII-D midplane with 123 honeycombed tangential chords 20 cm wide that span the vessel interior. Up to 30 bismuth germanate (BGO) scintillation detectors capture RE bremsstrahlung radiation for Pulse Height Analysis (PHA) capable of discriminating up to 20 000 pulses per second. Digital signal processing routines combining shaping filters are performed during PHA to reject noise and record gamma ray energy. The GRI setup and PHA algorithms will be described and initial data from experiments will be presented. A synthetic diagnostic is developed to generate the gamma ray spectrum of a GRI channel given the plasma information and a prescribed distribution function. Magnetic reconstructions of the plasma are used to calculate the angle between every GRI sightline and orient and discriminate gamma rays emitted by a field-aligned RE distribution function.
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- 2016
14. Use of Ar pellet ablation rate to estimate initial runaway electron seed population in DIII-D rapid shutdown experiments
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D. L. Rudakov, Paul Parks, Daisuke Shiraki, E. M. Hollmann, C. Cooper, I. Bykov, N.W. Eidietis, Carlos Paz-Soldan, M. G. O'Mullane, R. A. Moyer, Nicolas Jc Commaux, and Max E Austin
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Nuclear and High Energy Physics ,education.field_of_study ,Tokamak ,Argon ,Materials science ,DIII-D ,Shutdown ,medicine.medical_treatment ,Population ,Pellets ,chemistry.chemical_element ,Electron ,Condensed Matter Physics ,Ablation ,01 natural sciences ,010305 fluids & plasmas ,law.invention ,chemistry ,law ,0103 physical sciences ,medicine ,Atomic physics ,010306 general physics ,education ,QC - Abstract
Small (2–3 mm, 0.9–2 Pa · m3) argon pellets are used in the DIII-D tokamak to cause rapid shutdown (disruption) of discharges. The Ar pellet ablation is typically found to be much larger than expected from the thermal plasma electron temperature alone; the additional ablation is interpreted as being due to non-thermal runaway electrons (REs) formed during the pellet-induced temperature collapse. Simple estimates of the RE seed current using the enhanced ablation rate give values of order 1–10 kA, roughly consistent with estimates based on avalanche theory. Analytic estimates of the RE seed current based on the Dreicer formula tend to significantly underestimate it, while estimates based on the hot tail model significantly overestimate it.
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- 2016
15. The diversity of zinc-finger genes on human chromosome 19 provides an evolutionary mechanism for defense against inherited endogenous retroviruses
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Arnold J. Levine, Nicolas Jc, and Lukic S
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Endogenous retrovirus ,Tripartite Motif-Containing Protein 28 ,germline ,Genome ,Retrovirus ,Humans ,Copy-number variation ,Promoter Regions, Genetic ,Molecular Biology ,Gene ,Genetics ,Original Paper ,Binding Sites ,biology ,Endogenous Retroviruses ,Zinc Fingers ,Cell Biology ,biology.organism_classification ,retrotransposons ,Chromatin ,Repressor Proteins ,HEK293 Cells ,DNA methylation ,DNA Transposable Elements ,Human genome ,Paleovirology ,Chromosomes, Human, Pair 19 ,Zinc-fingers ,Retroviridae Infections ,Transcription Factors - Abstract
Endogenous retroviruses (ERVs) are remnants of ancient retroviral infections of the germ line that can remain capable of replication within the host genome. In the soma, DNA methylation and repressive chromatin keep the majority of this parasitic DNA transcriptionally silent. However, it is unclear how the host organism adapts to recognize and silence novel invading retroviruses that enter the germ line. Krueppel-Associated Box (KRAB)-associated protein 1 (KAP1) is a transcriptional regulatory factor that drives the epigenetic repression of many different loci in mammalian genomes. Here, we use published experimental data to provide evidence that human KAP1 is recruited to endogenous retroviral DNA by KRAB-containing zinc-finger transcription factors (TFs). Many of these zinc-finger genes exist in clusters associated with human chromosome 19. We demonstrate that these clusters are located at hotspots for copy number variation (CNV), generating a large and continuing diversity of zinc-finger TFs with new generations. These zinc-finger genes possess a wide variety of DNA binding affinities, but their role as transcriptional repressors is conserved. We also perform a computational study of the different ERVs that invaded the human genome during primate evolution. We find candidate zinc-finger repressors that arise in the genome for each ERV family that enters the genomes of primates. In particular, we show that those repressors that gained their binding affinity to retrovirus sequences at the same time as their targets invaded the human lineage are preferentially located on chromosome 19 (P-value: 3 × 10(-3)).
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- 2013
16. Measurement of toroidal variation in conducted heat loads in locked mode induced disruptions on DIII-D
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Eric Hollmann, R. A. Moyer, C.J. Lasnier, Nicolas Jc Commaux, Carlos Paz-Soldan, Daisuke Shiraki, N.W. Eidietis, and J.G. Watkins
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Physics ,Toroid ,Tokamak ,DIII-D ,Divertor ,Phase (waves) ,Mechanics ,Plasma ,Condensed Matter Physics ,01 natural sciences ,010305 fluids & plasmas ,law.invention ,Physics::Plasma Physics ,law ,0103 physical sciences ,Thermal ,Magnetohydrodynamics ,010306 general physics - Abstract
Locked mode disruptions with a controlled toroidal phase are produced in the DIII-D tokamak by locking to large non-axisymmetric applied magnetic perturbations with different toroidal phases. The disruption conducted heat loads are found to reach almost completely the divertor region, possibly due to not only strong inner leg detachment but also plasma motion and limiting on the outer divertor leg shelf. The outer leg conducted heat loads are found to have a significant toroidal variation of order ±30%, with a dominant n = 1 structure. The heat load phase is shifted from the initial locked mode phase in a way that is approximately consistent with heat loss into the scrape-off layer being enhanced at the mode island O-point outer midplane crossing. These measurements suggest that pre-existing locked modes can affect the conducted heat load structure during the thermal quench by affecting the thermal quench MHD phase. This is consistent with previous MHD simulations which indicated that pre-disruption locke...
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- 2018
17. Trends and repetition of non-fatal suicidal behaviour: analyses of the Gold Coast University Hospital’s Emergency Department
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Kõlves, Kairi, primary, Crompton, David, additional, Turner, Kathryn, additional, Stapelberg, Nicolas JC, additional, Khan, Ashar, additional, Robinson, Gail, additional, and de Leo, Diego, additional
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- 2018
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18. Plasma–surface interactions during tokamak disruptions and rapid shutdowns
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J.H. Yu, F. Saint-Laurent, Michael Lehnen, Todd Evans, A.N. James, J.C. Wesley, Robert Granetz, T.C. Jernigan, G. Maddaluno, G. Arnoux, Valeryi Sizyuk, R. Paccagnella, Paul Parks, N.W. Eidietis, V. Philipps, E. J. Strait, Matthew Reinke, A. Huber, Nicolas Jc Commaux, C.P.C. Wong, D.A. Humphreys, D.L. Rudakov, Eric Hollmann, and V.A. Izzo
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Nuclear and High Energy Physics ,Jet (fluid) ,DIII-D ,Tokamak ,Plasma surface ,Chemistry ,Nuclear engineering ,chemistry.chemical_element ,law.invention ,Nuclear physics ,Nuclear Energy and Engineering ,Runaway electrons ,law ,Thermal radiation ,ITER ,RUNAWAY ELECTRONS ,General Materials Science ,TRANSIENT HEAT LOADS ,Halo ,Current (fluid) ,Beryllium ,POWER LOAD - Abstract
Recent progress in understanding of disruptions and in developing methods to avoid disruption damage is presented. Nearly complete mitigation of conducted heat loads has been achieved with high-Z gas jet shutdown. The resulting local radiation heat flash melting in the main chamber might be a concern in ITER, especially with beryllium walls. During the current quench, significant vessel forces can occur due to halo currents I-halo; however, these are found to fall reliably below a boundary of (halo current fraction times halo current peaking factor)
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- 2011
19. A Technique for Producing Large Dual-Layer Pellets in Support of Disruption Mitigation Experiments
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C.R. Foust, S.K. Combs, T. C. Jernigan, Nicolas Jc Commaux, Jacob Leachman, Steven J. Meitner, and Larry R. Baylor
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Nuclear and High Energy Physics ,Materials science ,020209 energy ,Mechanical Engineering ,digestive, oral, and skin physiology ,Pellets ,Dual layer ,02 engineering and technology ,Cryogenics ,01 natural sciences ,010305 fluids & plasmas ,Nuclear Energy and Engineering ,0103 physical sciences ,Pellet ,0202 electrical engineering, electronic engineering, information engineering ,General Materials Science ,Composite material ,Civil and Structural Engineering - Abstract
A special single-shot pellet injection system that produces and accelerates large cryogenic pellets (~16mm diameter and composed of D2 or Ne) to relatively high speeds (>300 and 600 m/s, respective...
- Published
- 2011
20. Dissipation of post-disruption runaway electron plateaus by shattered pellet injection in DIII-D
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S.K. Combs, Nicolas Jc Commaux, Carlos Paz-Soldan, Larry R. Baylor, N.W. Eidietis, Steven J. Meitner, Eric Hollmann, Daisuke Shiraki, and C. M. Cooper
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Nuclear and High Energy Physics ,Materials science ,Tokamak ,DIII-D ,chemistry.chemical_element ,Plasma ,Electron ,Dissipation ,Condensed Matter Physics ,01 natural sciences ,010305 fluids & plasmas ,law.invention ,Neon ,chemistry ,Deuterium ,Impurity ,law ,0103 physical sciences ,Atomic physics ,010306 general physics - Abstract
We report on the first demonstration of dissipation of fully avalanched post-disruption runaway electron (RE) beams by shattered pellet injection in the DIII-D tokamak. Variation of the injected species shows that dissipation depends strongly on the species mixture, while comparisons with massive gas injection do not show a significant difference between dissipation by pellets or by gas, suggesting that the shattered pellet is rapidly ablated by the relativistic electrons before significant radial penetration into the runaway beam can occur. Pure or dominantly neon injection increases the RE current dissipation through pitch-angle scattering due to collisions with impurity ions. Deuterium injection is observed to have the opposite effect from neon, reducing the high-Z impurity content and thus decreasing the dissipation, and causing the background thermal plasma to completely recombine. When injecting mixtures of the two species, deuterium levels as low as ~10% of the total injected atoms are observed to adversely affect the resulting dissipation, suggesting that complete elimination of deuterium from the injection may be important for optimizing RE mitigation schemes.
- Published
- 2018
21. Alternative Techniques for Injecting Massive Quantities of Gas for Plasma-Disruption Mitigation
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T.C. Jernigan, S.K. Combs, C.R. Foust, J. M. McGill, Larry R. Baylor, D. T. Fehling, David A Rasmussen, John Caughman, Nicolas Jc Commaux, Paul Parks, and Steven J. Meitner
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Nuclear and High Energy Physics ,Tokamak ,Argon ,Materials science ,Nuclear engineering ,Refrigerator car ,Pellets ,Magnetic confinement fusion ,chemistry.chemical_element ,Injector ,Cryogenics ,Condensed Matter Physics ,law.invention ,chemistry ,law ,Rupture disc ,Atomic physics - Abstract
Injection of massive quantities of noble gases or D2 has proven to be effective at mitigating some of the deleterious effects of disruptions in tokamaks. Two alternative methods that might offer some advantages over the present technique for massive gas injection are ?shattering? massive pellets and employing close-coupled rupture disks. Laboratory testing has been carried out to evaluate their feasibility. For the study of massive pellets, a pipe-gun pellet injector cooled with a cryogenic refrigerator was fitted with a relatively large barrel (16.5-mm bore), and D2 and Ne pellets were made and were accelerated to speeds of ~ 600 and 300 m/s, respectively. Based on the successful proof-of-principle testing with the injector and a special double-impact target to shatter pellets, a similar system has been prepared and installed on DIII-D, with preliminary experiments already carried out. To study the applicability of rupture disks for disruption mitigation, a simple test apparatus was assembled in the laboratory. Commercially available rupture disks of 1-in nominal diameter were tested at conditions relevant for the application on tokamaks, including tests with Ar and He gases and rupture pressures of ~ 54 bar. Some technical and practical issues of implementing this technique on a tokamak are discussed.
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- 2010
22. Disruption-Mitigation-Technology Concepts and Implications for ITER
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Steven J. Meitner, David A Rasmussen, Michael Lehnen, Manfred Glugla, Larry R. Baylor, John Caughman, Paul Parks, Nicolas Jc Commaux, S.K. Combs, R. Pearce, T.C. Jernigan, and S. Maruyama
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Physics ,Nuclear and High Energy Physics ,Tokamak ,Helium gas ,Nuclear engineering ,chemistry.chemical_element ,Magnetic confinement fusion ,Plasma ,Condensed Matter Physics ,Collision ,law.invention ,Nuclear physics ,Heat flux ,chemistry ,Runaway electrons ,law ,Helium - Abstract
Disruptions on ITER present challenges to handle the intense heat flux, the large forces from halo currents, and the potential first wall damage from energetic runaway electrons. Injecting large quantities of material into the plasma during the disruption can reduce the plasma energy and increase its resistivity to mitigate these effects. Assessments of the amount of various mixtures and quantities of the material required have been made to provide collision mitigation of runaway-electron conversion, which is the most difficult challenge. The quantities of the material required (~0.5 MPa·m3 for deuterium or helium gas) are large enough to have implications on the design and operation of the vacuum system and tokamak exhaust processing system.
- Published
- 2010
23. Poloidal radiation asymmetries during disruption mitigation by massive gas injection on the DIII-D tokamak
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Nicolas Jc Commaux, Eric Hollmann, Daisuke Shiraki, Valerie Izzo, and N.W. Eidietis
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Physics ,Tokamak ,DIII-D ,chemistry.chemical_element ,Injector ,Plasma ,Effective radiated power ,Condensed Matter Physics ,01 natural sciences ,010305 fluids & plasmas ,law.invention ,Computational physics ,Neon ,chemistry ,law ,0103 physical sciences ,Emissivity ,Plasma diagnostics ,Atomic physics ,010306 general physics - Abstract
A comparison of radiated power poloidal peaking during disruption mitigation using massive gas injection at multiple poloidal positions on the DIII-D tokamak is presented. The two injectors are located poloidally above and below the low field side midplane and toroidally located within the quadrants to either side of the fast bolometry diagnostic used to measure the radiated power. Differing quantities of injected neon are compared. A strong dependence of impurity poloidal flows upon the injector location is observed. Injection from the upper half of the vessel results in strong poloidal flows over the top of the plasma to the high field side midplane, while lower injection exhibits far less pronounced poloidal flow that is oriented in the opposite direction. The poloidal location of both pre-thermal quench and thermal quench emissivity peaking shows a strong dependence upon the injector location, although the poloidal flow in the upper injection case results in a much broader distribution. The wall radia...
- Published
- 2017
24. Pellet interaction with runaway electrons
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J.H. Yu, S. Putvinski, Eric Hollmann, Paul Parks, E. J. Strait, George Tynan, Todd Evans, A.N. James, D.A. Humphreys, T.C. Jernigan, J.C. Wesley, Nicolas Jc Commaux, and Max E Austin
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Nuclear and High Energy Physics ,Argon ,Chemistry ,digestive, oral, and skin physiology ,Cyclotron ,Pellets ,chemistry.chemical_element ,Particle accelerator ,Cryogenics ,Plasma ,Electron ,law.invention ,Nuclear Energy and Engineering ,law ,Pellet ,General Materials Science ,Atomic physics - Abstract
We describe results from recent experiments studying interaction of solid polystyrene pellets with a runaway electron current channel generated after cryogenic argon pellet rapid shutdown of DIII-D. Fast camera imaging shows the pellet trajectory and continuum emission from the subsequent explosion, with geometric calibration providing detailed explosion analysis and runaway energy. Electron cyclotron emission also occurs, associated with knock-on electrons broken free from the pellet by RE which then accelerate and runaway, and also with a short lived hot plasma blown off the pellet surface. In addition, we compare heating and explosion times from observations and a model of pellet heating and breakdown by runaway interaction.
- Published
- 2011
25. Non-linear MHD modelling of ELM triggering by pellet injection in DIII-D and implications for ITER
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Nicolas Jc Commaux, A. Loarte, Gta Guido Huijsmans, Shimpei Futatani, T.H. Osborne, M.E. Fenstermacher, C.J. Lasnier, B. Pégourié, T.C. Jernigan, and Larry R. Baylor
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Nuclear and High Energy Physics ,Tokamak ,Materials science ,DIII-D ,Nuclear engineering ,Pellets ,Magnetic confinement fusion ,Plasma ,Condensed Matter Physics ,law.invention ,Nuclear physics ,law ,Pellet ,Magnetohydrodynamics ,Edge-localized mode - Abstract
Edge localized mode (ELM) triggering by pellet injection in the DIII-D tokamak has been simulated with the non-linear MHD code JOREK with a view to validating its physics models. JOREK has been subsequently applied to evaluate the requirements for ELM control by pellet injection in ITER. JOREK modelling results for DIII-D show that the key parameter for the triggering of ELMs by pellets is the value of the localized pressure perturbation caused by pellet injection which leads to a threshold minimum pellet size for a given injection velocity, injection geometry and H-mode plasma characteristics. The minimum pellet size for ELM triggering is found to depend on injection geometry with the largest value being required for injection at the outer midplane, intermediate for injection near the X-point and the smallest one for injection at the high-field side. The first results of studies for ELM triggering by pellet injection in ITER 15 MA Q = 10 plasmas with the foreseen injection geometry in ITER are presented.
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- 2014
- Full Text
- View/download PDF
26. Ultrasonographic anatomy and diagnosis of fetal uropathies affecting the upper urinary tract: II Nonobstructive uropathies
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Duval, JM, Milon, J, Coadou, Y, Blouet, JM, Langella, B, Bourgin, T, Nicolas, JC, Fremond, B, Duval, JC, and Jouan, H
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- 1986
- Full Text
- View/download PDF
27. Reduction of edge-localized mode intensity using high-repetition-rate pellet injection in tokamak H-mode plasmas
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S.K. Combs, Ezekial A Unterberg, N.H. Brooks, Nicolas Jc Commaux, A. Loarte, Larry R. Baylor, R.A. Moyer, E. J. Strait, R.C. Isler, Steven J. Meitner, T.H. Osborne, C.J. Lasnier, P. B. Snyder, M.E. Fenstermacher, P. B. Parks, T.C. Jernigan, and Todd Evans
- Subjects
Materials science ,Tokamak ,Pedestal ,Deuterium ,law ,Divertor ,Pellets ,General Physics and Astronomy ,Plasma ,Atomic physics ,Edge-localized mode ,Instability ,law.invention - Abstract
High repetition rate injection of deuterium pellets from the low-field side (LFS) of the DIII-D tokamak is shown to trigger high-frequency edge-localized modes (ELMs) at up to $12\ifmmode\times\else\texttimes\fi{}$ the low natural ELM frequency in $H$-mode deuterium plasmas designed to match the ITER baseline configuration in shape, normalized beta, and input power just above the $H$-mode threshold. The pellet size, velocity, and injection location were chosen to limit penetration to the outer 10% of the plasma. The resulting perturbations to the plasma density and energy confinement time are thus minimal ($l10%$). The triggered ELMs occur at much lower normalized pedestal pressure than the natural ELMs, suggesting that the pellet injection excites a localized high-$n$ instability. Triggered ELMs produce up to $12\ifmmode\times\else\texttimes\fi{}$ lower energy and particle fluxes to the divertor, and result in a strong decrease in plasma core impurity density. These results show for the first time that shallow, LFS pellet injection can dramatically accelerate the ELM cycle and reduce ELM energy fluxes on plasma facing components, and is a viable technique for real-time control of ELMs in ITER.
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- 2012
28. Thermal quench mitigation and current quench control by injection of mixed species shattered pellets in DIII-D
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C.J. Lasnier, Larry R. Baylor, Daisuke Shiraki, R. A. Moyer, Eric Hollmann, N.W. Eidietis, and Nicolas Jc Commaux
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Physics ,Tokamak ,DIII-D ,Divertor ,Pellets ,chemistry.chemical_element ,Plasma ,Condensed Matter Physics ,01 natural sciences ,010305 fluids & plasmas ,law.invention ,Neon ,chemistry ,law ,0103 physical sciences ,Pellet ,Current (fluid) ,Atomic physics ,010306 general physics - Abstract
Injection of large shattered pellets composed of variable quantities of the main ion species (deuterium) and high-Z impurities (neon) in the DIII-D tokamak demonstrates control of thermal quench (TQ) and current quench (CQ) properties in mitigated disruptions. As the pellet composition is varied, TQ radiation fractions increase continuously with the quantity of radiating impurity in the pellet, with a corresponding decrease in divertor heating. Post-TQ plasma resistivities increase as a result of the higher radiation fraction, allowing control of current decay timescales based on the pellet composition. Magnetic reconstructions during the CQ show that control of the current decay rate allows continuous variation of the minimum safety factor during the vertically unstable disruption, reducing the halo current fraction and resulting vessel displacement. Both TQ and CQ characteristics are observed to saturate at relatively low quantities of neon, indicating that effective mitigation of disruption loads by shattered pellet injection (SPI) can be achieved with modest impurity quantities, within injection quantities anticipated for ITER. This mixed species SPI technique provides a possible approach for tuning disruption properties to remain within the limited ranges allowed in the ITER design.
- Published
- 2016
29. High frequency pacing of edge localized modes by injection of lithium granules in DIII-D H-mode discharges
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M. A. Van Zeeland, Shaun Haskey, Nicolas Jc Commaux, Robert Lunsford, Larry R. Baylor, R. J. Groebner, Rajesh Maingi, Daisuke Shiraki, T.H. Osborne, Colin Chrystal, M.J. Makowski, Brian Grierson, Raffi Nazikian, G.L. Jackson, A. L. Roquemore, Alessandro Bortolon, C.J. Lasnier, A. Nagy, Paul Parks, D. K. Mansfield, and Erik P. Gilson
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Nuclear and High Energy Physics ,Tokamak ,Materials science ,DIII-D ,Granule (cell biology) ,Injector ,Plasma ,Condensed Matter Physics ,01 natural sciences ,010305 fluids & plasmas ,law.invention ,Pedestal ,Heat flux ,law ,0103 physical sciences ,Metallic impurities ,Atomic physics ,010306 general physics - Abstract
A newly installed Lithium Granule Injector (LGI) was used to pace edge localized modes (ELM) in DIII-D. ELM pacing efficiency was studied injecting lithium granules of nominal diameter 0.3–0.9 mm, speed of 50–120 m s−1 and average injection rates up to 100 Hz for 0.9 mm granules and up to 700 Hz for 0.3 mm granules. The efficiency of ELM triggering was found to depend strongly on size of the injected granules, with triggering efficiency close to 100% obtained with 0.9 mm diameter granules, lower with smaller sizes, and weakly depending on granule velocity. Robust ELM pacing was demonstrated in ITER-like plasmas for the entire shot length, at ELM frequencies 3–5 times larger than the ‘natural’ ELM frequency observed in reference discharges. Within the range of ELM frequencies obtained, the peak ELM heat flux at the outer strike point was reduced with increasing pacing frequency. The peak heat flux reduction at the inner strike point appears to saturate at high pacing frequency. Lithium was found in the plasma core, with a concurrent reduction of metallic impurities and carbon. Overall, high frequency ELM pacing using the lithium granule injection appears to be compatible with both H-mode energy confinement and attractive H-mode pedestal characteristics, but further assessment is needed to determine whether the projected heat flux reduction required for ITER can be met.
- Published
- 2016
30. First demonstration of rapid shutdown using neon shattered pellet injection for thermal quench mitigation on DIII-D
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C.J. Lasnier, C.R. Foust, Nicolas Jc Commaux, N.W. Eidietis, S.K. Combs, R.A. Moyer, Daisuke Shiraki, Steven J. Meitner, T.C. Jernigan, Eric Hollmann, and Larry R. Baylor
- Subjects
Nuclear and High Energy Physics ,Materials science ,DIII-D ,Divertor ,chemistry.chemical_element ,Plasma ,Radiation ,Effective radiated power ,Dissipation ,Condensed Matter Physics ,01 natural sciences ,010305 fluids & plasmas ,Nuclear physics ,Neon ,chemistry ,0103 physical sciences ,010306 general physics ,Helium - Abstract
Shattered pellet injection (SPI) is one of the prime candidates for the ITER disruption mitigation system because of its deeper penetration and larger particle flux than massive gas injection (MGI) (Taylor et al 1999 Phys. Plasmas 6 1872) using deuterium (Commaux et al 2010 Nucl. Fusion 50 112001, Combs et al 2010 IEEE Trans. Plasma Sci. 38 400, Baylor et al 2009 Nucl. Fusion 49 085013). The ITER disruption mitigation system will likely use mostly high Z species such as neon because of more effective thermal mitigation and pumping constraints on the maximum amount of deuterium or helium that could be injected. An upgrade of the SPI on DIII-D enables ITER relevant injection characteristics in terms of quantities and gas species. This upgraded SPI system was used on DIII-D for the first time in 2014 for a direct comparison with MGI using identical quantities of neon. This comparison enabled the measurements of density perturbations during the thermal quench (TQ) and radiated power and heat loads to the divertor. It showed that SPI using similar quantities of neon provided a faster and stronger density perturbation and neon assimilation, which resulted in a lower conducted energy to the divertor and a faster TQ onset. Radiated power data analysis shows that this was probably due to the much deeper penetration of the neon in the plasma inducing a higher core radiation than in the MGI case. This experiment shows also that the MHD activity during an SPI shutdown (especially during the TQ) is quite different compared to MGI. This favorable TQ energy dissipation was obtained while keeping the current quench (CQ) duration within acceptable limits when scaled to ITER.
- Published
- 2016
31. Publisher’s Note: 'Changes in particle transport as a result of resonant magnetic perturbations in DIII-D' [Phys. Plasmas 19, 056503 (2012)]
- Author
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Kenneth W Gentle, George McKee, M.E. Fenstermacher, G. Wang, H. Reimerdes, E. J. Doyle, Oliver Schmitz, R.A. Moyer, W. M. Solomon, T. L. Rhodes, Lei Zeng, Saskia Mordijck, G. M. Staebler, and Nicolas Jc Commaux
- Subjects
Nuclear physics ,Physics ,Two-stream instability ,DIII-D ,Waves in plasmas ,Magnetic confinement fusion ,ddc:530 ,Plasma ,Condensed Matter Physics ,Plasma stability ,Resonant magnetic perturbations ,Magnetic field - Abstract
Publisher s Note: Changes in particle transport as a result of resonant magnetic perturbations in DIII-D [Phys. Plasmas 19, 056503 (2012)]a) In the Invited Papers from the 53rd Annual Meeting of the APS Division of Plasma Physics of the May 2012 issue of the journal, this article was originally published online and in print in the incorrect section; it was published within Ionospheric, Solar-System and Astrophysical Plasmas (Sec. 65) instead of Magnetically Confined Plasmas, Heating, Confinement (Sec. 61). AIP apologizes for this error. a)
- Published
- 2012
32. Mitigation of upward and downward vertical displacement event heat loads with upper or lower massive gas injection in DIII-D
- Author
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Daisuke Shiraki, Nicolas Jc Commaux, R. A. Moyer, C.J. Lasnier, Paul Parks, N.W. Eidietis, and Eric Hollmann
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Physics ,Jet (fluid) ,DIII-D ,Phase (waves) ,chemistry.chemical_element ,Mechanics ,Plasma ,Effective radiated power ,Condensed Matter Physics ,Neon ,chemistry ,Thermal ,Vertical displacement ,Atomic physics - Abstract
Intentionally triggered upward and downward vertical displacement events (VDEs) leading to disruptions were pre-emptively mitigated with neon massive gas injection (MGI) coming from either above or below the plasma. Global indicators of disruption mitigation effectiveness (conducted heat loads, radiated power, and vessel motion) do not show a clear improvement when mitigating with the gas jet located closer to the VDE impact area. A clear trend of improved mitigation is observed for earlier MGI timing relative to the VDE impact time. The plasma edge magnetic perturbation is seen to lock to a preferential phase during the VDE thermal quench, but this phase is not clearly matched by preliminary attempts to fit to the conducted heat load phase. Clear indications of plasma infra-red (IR) emission are observed both before and during the disruptions. This IR emission can affect calculation of disruption heat loads; here, the time decay of post-disruption IR signals is used to correct for this effect.
- Published
- 2015
33. Massive pellet and rupture disk testing for disruption mitigation applications
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S.K. Combs, C.R. Foust, David A Rasmussen, John Caughman, Larry R. Baylor, D. T. Fehling, Paul Parks, T.C. Jernigan, Nicolas Jc Commaux, J. M. McGill, and Steven J. Meitner
- Subjects
Materials science ,Tokamak ,DIII-D ,law ,Nuclear engineering ,Divertor ,Rupture disc ,Pellets ,Refrigerator car ,Injector ,Cryogenics ,Atomic physics ,law.invention - Abstract
Injection of massive quantities of noble gases or D 2 has proven to be effective at mitigating some of the deleterious effects of disruptions in tokamaks. Two alternative methods that might offer some advantages over the present technique for massive gas injection are “shattering” massive pellets and employing close-coupled rupture disks. Laboratory testing has been carried out to evaluate their feasibility. For the study of massive pellets, a pipe gun pellet injector cooled with a cryogenic refrigerator was fitted with a relatively large barrel (16.5 mm bore), and D 2 and Ne pellets were made and were accelerated to speeds of ∼600 and 300 m/s, respectively. Based on the successful proof-of-principle testing with the injector and a special double-impact target to shatter pellets, a similar system has been prepared and installed on DIII-D and should be ready for experiments later this year. To study the applicability of rupture disks for disruption mitigation, a simple test apparatus was assembled in the lab. Commercially available rupture disks of 1 in. nominal diameter were tested at conditions relevant for the application on tokamaks, including tests with Ar and He gases and rupture pressures of ∼54 bar. Some technical and practical issues of implementing this technique on a tokamak are discussed.
- Published
- 2009
34. Characterization of MHD activity and its influence on radiation asymmetries during massive gas injection in DIII-D
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R.A. Moyer, Valerie Izzo, Larry R. Baylor, Eric Hollmann, N.W. Eidietis, Daisuke Shiraki, Nicolas Jc Commaux, and Carlos Paz-Soldan
- Subjects
Physics ,Nuclear and High Energy Physics ,Tokamak ,Toroid ,DIII-D ,Plasma ,Radiation ,Effective radiated power ,Condensed Matter Physics ,law.invention ,Nuclear physics ,Physics::Plasma Physics ,law ,Magnetohydrodynamic drive ,Magnetohydrodynamics ,Atomic physics - Abstract
Measurements from the DIII-D tokamak show that toroidal radiation asymmetries during fast shutdown by massive gas injection (MGI) are largely driven by n = 1 magnetohydrodynamic modes during the thermal quench. The phenomenology of these modes, which are driven unstable by pro le changes as the thermal energy is quenched, is described based on detailed magnetic measurements. Here, the toroidal evolution of the dominantly n = 1 perturbation is understood to be a function of three parameters: the location of the MGI port, pre-MGI plasma rotation, and n = 1 error elds. Here, the resulting level of radiation asymmetry in these DIII-D plasmas is modest, with a toroidal peaking factor (TPF) of 1:2 ± 0:1 for the total thermal quench energy and 1:4 ± 0:3 for the peak radiated power, both of which are below the estimated limit for ITER (TPF ≈ 2).
- Published
- 2015
35. The role of MHD in 3D aspects of massive gas injection
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Eric Hollmann, Roger Raman, Nicolas Jc Commaux, Charles Lasnier, N.W. Eidietis, David A. Humphreys, Paul Parks, Daisuke Shiraki, Robert Granetz, E. J. Strait, Carlos Paz-Soldan, Valerie Izzo, and R.A. Moyer
- Subjects
Physics ,Nuclear and High Energy Physics ,Toroid ,Tokamak ,Field line ,Mechanics ,Plasma ,Effective radiated power ,Condensed Matter Physics ,Neutral beam injection ,law.invention ,Heat flux ,law ,Magnetohydrodynamics ,Atomic physics - Abstract
Simulations of massive gas injection for disruption mitigation in DIII-D are carried out to compare the toroidal peaking of radiated power for the cases of one and two gas jets. The radiation toroidal peaking factor (TPF) results from a combination of the distribution of impurities and the distribution of heat flux associated with the mode. When ignoring the effects of strong uni-directional neutral beam injection and rotation present in the experiment, the injected impurities are found to spread helically along field lines preferentially toward the high-field-side, which is explained in terms of a nozzle equation. Therefore when considering the plasma rest frame, reversing the current direction also reverses the toroidal direction of impurity spreading. During the pre-thermal quench phase of the disruption, the toroidal peaking of radiated power is reduced in a straightforward manner by increasing from one to two gas jets. However, during the thermal quench phase, reduction in the TPF is achieved only for a particular arrangement of the two gas valves with respect to the field line pitch. In particular, the relationship between the two valve locations and the 1/1 mode phase is critical, where gas valve spacing that is coherent with 1/1 symmetry effectively reduces TPF.
- Published
- 2015
36. Protection of mammalian cell used in biosensors by coating with a polyelectrolyte shell
- Author
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Germain, Marie, Balaguer, P., Nicolas, Jc, Lopez, F., Esteve, Jp, Sukhorukov, Gb, Winterhalter, M., Richard-Foy, H., Fournier, D., Laboratoire de biologie moléculaire eucaryote (LBME), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Centre de Biologie Intégrative (CBI), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
- Published
- 2006
37. Long Pulse Operation on Tore-Supra: Towards Steady State
- Author
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B. Schunke, A. Géraud, L. Colas, B. Pégourié, P. Monier-Garbet, Patrick Maget, F. Saint-Laurent, E. Dufour, T. Loarer, C. Brosset, James Paul Gunn, V. Basiuk, S. Bremond, R. Mitteau, J.C. Vallet, M. Chantant, G.T. Hoang, P. Hertout, F. Kazarian, J. Bucalossi, D. Mazon, E. Tsitrone, R. Guirlet, Nicolas Jc Commaux, and P. Moreau
- Subjects
Physics ,Steady state (electronics) ,business.industry ,Oscillation ,Nuclear engineering ,Electrical engineering ,Plasma ,Tore Supra ,Physics::Plasma Physics ,Pinch ,Electron temperature ,Plasma diagnostics ,Magnetohydrodynamics ,business - Abstract
The experimental programme of Tore Supra is devoted to the study of technology and physics issues associated to long‐duration high performance discharges. This new domain of operation requires simultaneously and in steady state: heat removal capability, particle exhaust, fully non‐inductive current drive, advanced technology integration and real time plasma control. The long discharge allows for addressing new time scale physic such as the wall particle retention and erosion. Moreover, the physics of fully non‐inductive discharges is full of novelty, namely: the MHD stability, the slow spontaneous oscillation of the central electron temperature or the outstanding inward particle pinch.
- Published
- 2006
38. Radiation asymmetries during disruptions on DIII-D caused by massive gas injectiona)
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R.A. Moyer, Nicolas Jc Commaux, J.C. Wesley, S.K. Combs, C.R. Foust, Larry R. Baylor, N.W. Eidietis, Valerie Izzo, C.J. Lasnier, Paul Parks, T.C. Jernigan, Steven J. Meitner, D.A. Humphreys, and Eric Hollmann
- Subjects
Physics ,Tokamak ,Toroid ,DIII-D ,Mechanics ,Plasma ,Effective radiated power ,Condensed Matter Physics ,law.invention ,Nuclear physics ,law ,Heat transfer ,Vertical displacement ,Magnetohydrodynamics - Abstract
One of the major challenges that the ITER tokamak will have to face during its operations are disruptions. During the last few years, it has been proven that the global consequences of a disruption can be mitigated by the injection of large quantities of impurities. But one aspect that has been difficult to study was the possibility of local effects inside the torus during such injection that could damage a portion of the device despite the global heat losses and generated currents remaining below design parameter. 3D MHD simulations show that there is a potential for large toroidal asymmetries of the radiated power during impurity injection due to the interaction between the particle injection plume and a large n = 1 mode. Another aspect of 3D effects is the potential occurrence of Vertical Displacement Events (VDE), which could induce large poloidal heat load asymmetries. This potential deleterious effect of 3D phenomena has been studied on the DIII-D tokamak, thanks to the implementation of a multi-location massive gas injection (MGI) system as well as new diagnostic capabilities. This study showed the existence of a correlation between the location of the n = 1 mode and the local heat load on the plasma facing components but shows also that this effect is much smaller than anticipated (peaking factor of ∼1.1 vs 3-4 according to the simulations). There seems to be no observable heat load on the first wall of DIII-D at the location of the impurity injection port as well as no significant radiation asymmetries whether one or 2 valves are fired. This study enabled the first attempt of mitigation of a VDE using impurity injection at different poloidal locations. The results showed a more favorable heat deposition when the VDE is mitigated early (right at the onset) by impurity injection. No significant improvement of the heat load mitigation efficiency has been observed for late particle injection whether the injection is done “in the way” of the VDE (upward VDE mitigated by injection from the upper part of the vessel vs the lower part) or not.
- Published
- 2014
39. The contribution of major depression to the global burden of ischemic heart disease: a comparative risk assessment
- Author
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Charlson, Fiona J, primary, Moran, Andrew E, additional, Freedman, Greg, additional, Norman, Rosana E, additional, Stapelberg, Nicolas JC, additional, Baxter, Amanda J, additional, Vos, Theo, additional, and Whiteford, Harvey A, additional
- Published
- 2013
- Full Text
- View/download PDF
40. Disability-adjusted life years (DALYs) for 291 diseases and injuries in 21 regions, 1990–2010: a systematic analysis for the Global Burden of Disease Study 2010
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Murray, Christopher J L, primary, Vos, Theo, additional, Lozano, Rafael, additional, Naghavi, Mohsen, additional, Flaxman, Abraham D, additional, Michaud, Catherine, additional, Ezzati, Majid, additional, Shibuya, Kenji, additional, Salomon, Joshua A, additional, Abdalla, Safa, additional, Aboyans, Victor, additional, Abraham, Jerry, additional, Ackerman, Ilana, additional, Aggarwal, Rakesh, additional, Ahn, Stephanie Y, additional, Ali, Mohammed K, additional, AlMazroa, Mohammad A, additional, Alvarado, Miriam, additional, Anderson, H Ross, additional, Anderson, Laurie M, additional, Andrews, Kathryn G, additional, Atkinson, Charles, additional, Baddour, Larry M, additional, Bahalim, Adil N, additional, Barker-Collo, Suzanne, additional, Barrero, Lope H, additional, Bartels, David H, additional, Basáñez, Maria-Gloria, additional, Baxter, Amanda, additional, Bell, Michelle L, additional, Benjamin, Emelia J, additional, Bennett, Derrick, additional, Bernabé, Eduardo, additional, Bhalla, Kavi, additional, Bhandari, Bishal, additional, Bikbov, Boris, additional, Abdulhak, Aref Bin, additional, Birbeck, Gretchen, additional, Black, James A, additional, Blencowe, Hannah, additional, Blore, Jed D, additional, Blyth, Fiona, additional, Bolliger, Ian, additional, Bonaventure, Audrey, additional, Boufous, Soufiane, additional, Bourne, Rupert, additional, Boussinesq, Michel, additional, Braithwaite, Tasanee, additional, Brayne, Carol, additional, Bridgett, Lisa, additional, Brooker, Simon, additional, Brooks, Peter, additional, Brugha, Traolach S, additional, Bryan-Hancock, Claire, additional, Bucello, Chiara, additional, Buchbinder, Rachelle, additional, Buckle, Geoffrey, additional, Budke, Christine M, additional, Burch, Michael, additional, Burney, Peter, additional, Burstein, Roy, additional, Calabria, Bianca, additional, Campbell, Benjamin, additional, Canter, Charles E, additional, Carabin, Hélène, additional, Carapetis, Jonathan, additional, Carmona, Loreto, additional, Cella, Claudia, additional, Charlson, Fiona, additional, Chen, Honglei, additional, Cheng, Andrew Tai-Ann, additional, Chou, David, additional, Chugh, Sumeet S, additional, Coffeng, Luc E, additional, Colan, Steven D, additional, Colquhoun, Samantha, additional, Colson, K Ellicott, additional, Condon, John, additional, Connor, Myles D, additional, Cooper, Leslie T, additional, Corriere, Matthew, additional, Cortinovis, Monica, additional, de Vaccaro, Karen Courville, additional, Couser, William, additional, Cowie, Benjamin C, additional, Criqui, Michael H, additional, Cross, Marita, additional, Dabhadkar, Kaustubh C, additional, Dahiya, Manu, additional, Dahodwala, Nabila, additional, Damsere-Derry, James, additional, Danaei, Goodarz, additional, Davis, Adrian, additional, Leo, Diego De, additional, Degenhardt, Louisa, additional, Dellavalle, Robert, additional, Delossantos, Allyne, additional, Denenberg, Julie, additional, Derrett, Sarah, additional, Des Jarlais, Don C, additional, Dharmaratne, Samath D, additional, Dherani, Mukesh, additional, Diaz-Torne, Cesar, additional, Dolk, Helen, additional, Dorsey, E Ray, additional, Driscoll, Tim, additional, Duber, Herbert, additional, Ebel, Beth, additional, Edmond, Karen, additional, Elbaz, Alexis, additional, Ali, Suad Eltahir, additional, Erskine, Holly, additional, Erwin, Patricia J, additional, Espindola, Patricia, additional, Ewoigbokhan, Stalin E, additional, Farzadfar, Farshad, additional, Feigin, Valery, additional, Felson, David T, additional, Ferrari, Alize, additional, Ferri, Cleusa P, additional, Fèvre, Eric M, additional, Finucane, Mariel M, additional, Flaxman, Seth, additional, Flood, Louise, additional, Foreman, Kyle, additional, Forouzanfar, Mohammad H, additional, Fowkes, Francis Gerry R, additional, Fransen, Marlene, additional, Freeman, Michael K, additional, Gabbe, Belinda J, additional, Gabriel, Sherine E, additional, Gakidou, Emmanuela, additional, Ganatra, Hammad A, additional, Garcia, Bianca, additional, Gaspari, Flavio, additional, Gillum, Richard F, additional, Gmel, Gerhard, additional, Gonzalez-Medina, Diego, additional, Gosselin, Richard, additional, Grainger, Rebecca, additional, Grant, Bridget, additional, Groeger, Justina, additional, Guillemin, Francis, additional, Gunnell, David, additional, Gupta, Ramyani, additional, Haagsma, Juanita, additional, Hagan, Holly, additional, Halasa, Yara A, additional, Hall, Wayne, additional, Haring, Diana, additional, Haro, Josep Maria, additional, Harrison, James E, additional, Havmoeller, Rasmus, additional, Hay, Roderick J, additional, Higashi, Hideki, additional, Hill, Catherine, additional, Hoen, Bruno, additional, Hoffman, Howard, additional, Hotez, Peter J, additional, Hoy, Damian, additional, Huang, John J, additional, Ibeanusi, Sydney E, additional, Jacobsen, Kathryn H, additional, James, Spencer L, additional, Jarvis, Deborah, additional, Jasrasaria, Rashmi, additional, Jayaraman, Sudha, additional, Johns, Nicole, additional, Jonas, Jost B, additional, Karthikeyan, Ganesan, additional, Kassebaum, Nicholas, additional, Kawakami, Norito, additional, Keren, Andre, additional, Khoo, Jon-Paul, additional, King, Charles H, additional, Knowlton, Lisa Marie, additional, Kobusingye, Olive, additional, Koranteng, Adofo, additional, Krishnamurthi, Rita, additional, Laden, Francine, additional, Lalloo, Ratilal, additional, Laslett, Laura L, additional, Lathlean, Tim, additional, Leasher, Janet L, additional, Lee, Yong Yi, additional, Leigh, James, additional, Levinson, Daphna, additional, Lim, Stephen S, additional, Limb, Elizabeth, additional, Lin, John Kent, additional, Lipnick, Michael, additional, Lipshultz, Steven E, additional, Liu, Wei, additional, Loane, Maria, additional, Ohno, Summer Lockett, additional, Lyons, Ronan, additional, Mabweijano, Jacqueline, additional, MacIntyre, Michael F, additional, Malekzadeh, Reza, additional, Mallinger, Leslie, additional, Manivannan, Sivabalan, additional, Marcenes, Wagner, additional, March, Lyn, additional, Margolis, David J, additional, Marks, Guy B, additional, Marks, Robin, additional, Matsumori, Akira, additional, Matzopoulos, Richard, additional, Mayosi, Bongani M, additional, McAnulty, John H, additional, McDermott, Mary M, additional, McGill, Neil, additional, McGrath, John, additional, Medina-Mora, Maria Elena, additional, Meltzer, Michele, additional, Memish, Ziad A, additional, Mensah, George A, additional, Merriman, Tony R, additional, Meyer, Ana-Claire, additional, Miglioli, Valeria, additional, Miller, Matthew, additional, Miller, Ted R, additional, Mitchell, Philip B, additional, Mock, Charles, additional, Mocumbi, Ana Olga, additional, Moffitt, Terrie E, additional, Mokdad, Ali A, additional, Monasta, Lorenzo, additional, Montico, Marcella, additional, Moradi-Lakeh, Maziar, additional, Moran, Andrew, additional, Morawska, Lidia, additional, Mori, Rintaro, additional, Murdoch, Michele E, additional, Mwaniki, Michael K, additional, Naidoo, Kovin, additional, Nair, M Nathan, additional, Naldi, Luigi, additional, Narayan, K M Venkat, additional, Nelson, Paul K, additional, Nelson, Robert G, additional, Nevitt, Michael C, additional, Newton, Charles R, additional, Nolte, Sandra, additional, Norman, Paul, additional, Norman, Rosana, additional, O'Donnell, Martin, additional, O'Hanlon, Simon, additional, Olives, Casey, additional, Omer, Saad B, additional, Ortblad, Katrina, additional, Osborne, Richard, additional, Ozgediz, Doruk, additional, Page, Andrew, additional, Pahari, Bishnu, additional, Pandian, Jeyaraj Durai, additional, Rivero, Andrea Panozo, additional, Patten, Scott B, additional, Pearce, Neil, additional, Padilla, Rogelio Perez, additional, Perez-Ruiz, Fernando, additional, Perico, Norberto, additional, Pesudovs, Konrad, additional, Phillips, David, additional, Phillips, Michael R, additional, Pierce, Kelsey, additional, Pion, Sébastien, additional, Polanczyk, Guilherme V, additional, Polinder, Suzanne, additional, Pope, C Arden, additional, Popova, Svetlana, additional, Porrini, Esteban, additional, Pourmalek, Farshad, additional, Prince, Martin, additional, Pullan, Rachel L, additional, Ramaiah, Kapa D, additional, Ranganathan, Dharani, additional, Razavi, Homie, additional, Regan, Mathilda, additional, Rehm, Jürgen T, additional, Rein, David B, additional, Remuzzi, Guiseppe, additional, Richardson, Kathryn, additional, Rivara, Frederick P, additional, Roberts, Thomas, additional, Robinson, Carolyn, additional, De Leòn, Felipe Rodriguez, additional, Ronfani, Luca, additional, Room, Robin, additional, Rosenfeld, Lisa C, additional, Rushton, Lesley, additional, Sacco, Ralph L, additional, Saha, Sukanta, additional, Sampson, Uchechukwu, additional, Sanchez-Riera, Lidia, additional, Sanman, Ella, additional, Schwebel, David C, additional, Scott, James Graham, additional, Segui-Gomez, Maria, additional, Shahraz, Saeid, additional, Shepard, Donald S, additional, Shin, Hwashin, additional, Shivakoti, Rupak, additional, Silberberg, Donald, additional, Singh, David, additional, Singh, Gitanjali M, additional, Singh, Jasvinder A, additional, Singleton, Jessica, additional, Sleet, David A, additional, Sliwa, Karen, additional, Smith, Emma, additional, Smith, Jennifer L, additional, Stapelberg, Nicolas JC, additional, Steer, Andrew, additional, Steiner, Timothy, additional, Stolk, Wilma A, additional, Stovner, Lars Jacob, additional, Sudfeld, Christopher, additional, Syed, Sana, additional, Tamburlini, Giorgio, additional, Tavakkoli, Mohammad, additional, Taylor, Hugh R, additional, Taylor, Jennifer A, additional, Taylor, William J, additional, Thomas, Bernadette, additional, Thomson, W Murray, additional, Thurston, George D, additional, Tleyjeh, Imad M, additional, Tonelli, Marcello, additional, Towbin, Jeffrey A, additional, Truelsen, Thomas, additional, Tsilimbaris, Miltiadis K, additional, Ubeda, Clotilde, additional, Undurraga, Eduardo A, additional, van der Werf, Marieke J, additional, van Os, Jim, additional, Vavilala, Monica S, additional, Venketasubramanian, N, additional, Wang, Mengru, additional, Wang, Wenzhi, additional, Watt, Kerrianne, additional, Weatherall, David J, additional, Weinstock, Martin A, additional, Weintraub, Robert, additional, Weisskopf, Marc G, additional, Weissman, Myrna M, additional, White, Richard A, additional, Whiteford, Harvey, additional, Wiebe, Natasha, additional, Wiersma, Steven T, additional, Wilkinson, James D, additional, Williams, Hywel C, additional, Williams, Sean RM, additional, Witt, Emma, additional, Wolfe, Frederick, additional, Woolf, Anthony D, additional, Wulf, Sarah, additional, Yeh, Pon-Hsiu, additional, Zaidi, Anita KM, additional, Zheng, Zhi-Jie, additional, Zonies, David, additional, and Lopez, Alan D, additional
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- 2012
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- View/download PDF
41. A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990–2010: a systematic analysis for the Global Burden of Disease Study 2010
- Author
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Lim, Stephen S, primary, Vos, Theo, additional, Flaxman, Abraham D, additional, Danaei, Goodarz, additional, Shibuya, Kenji, additional, Adair-Rohani, Heather, additional, AlMazroa, Mohammad A, additional, Amann, Markus, additional, Anderson, H Ross, additional, Andrews, Kathryn G, additional, Aryee, Martin, additional, Atkinson, Charles, additional, Bacchus, Loraine J, additional, Bahalim, Adil N, additional, Balakrishnan, Kalpana, additional, Balmes, John, additional, Barker-Collo, Suzanne, additional, Baxter, Amanda, additional, Bell, Michelle L, additional, Blore, Jed D, additional, Blyth, Fiona, additional, Bonner, Carissa, additional, Borges, Guilherme, additional, Bourne, Rupert, additional, Boussinesq, Michel, additional, Brauer, Michael, additional, Brooks, Peter, additional, Bruce, Nigel G, additional, Brunekreef, Bert, additional, Bryan-Hancock, Claire, additional, Bucello, Chiara, additional, Buchbinder, Rachelle, additional, Bull, Fiona, additional, Burnett, Richard T, additional, Byers, Tim E, additional, Calabria, Bianca, additional, Carapetis, Jonathan, additional, Carnahan, Emily, additional, Chafe, Zoe, additional, Charlson, Fiona, additional, Chen, Honglei, additional, Chen, Jian Shen, additional, Cheng, Andrew Tai-Ann, additional, Child, Jennifer Christine, additional, Cohen, Aaron, additional, Colson, K Ellicott, additional, Cowie, Benjamin C, additional, Darby, Sarah, additional, Darling, Susan, additional, Davis, Adrian, additional, Degenhardt, Louisa, additional, Dentener, Frank, additional, Des Jarlais, Don C, additional, Devries, Karen, additional, Dherani, Mukesh, additional, Ding, Eric L, additional, Dorsey, E Ray, additional, Driscoll, Tim, additional, Edmond, Karen, additional, Ali, Suad Eltahir, additional, Engell, Rebecca E, additional, Erwin, Patricia J, additional, Fahimi, Saman, additional, Falder, Gail, additional, Farzadfar, Farshad, additional, Ferrari, Alize, additional, Finucane, Mariel M, additional, Flaxman, Seth, additional, Fowkes, Francis Gerry R, additional, Freedman, Greg, additional, Freeman, Michael K, additional, Gakidou, Emmanuela, additional, Ghosh, Santu, additional, Giovannucci, Edward, additional, Gmel, Gerhard, additional, Graham, Kathryn, additional, Grainger, Rebecca, additional, Grant, Bridget, additional, Gunnell, David, additional, Gutierrez, Hialy R, additional, Hall, Wayne, additional, Hoek, Hans W, additional, Hogan, Anthony, additional, Hosgood, H Dean, additional, Hoy, Damian, additional, Hu, Howard, additional, Hubbell, Bryan J, additional, Hutchings, Sally J, additional, Ibeanusi, Sydney E, additional, Jacklyn, Gemma L, additional, Jasrasaria, Rashmi, additional, Jonas, Jost B, additional, Kan, Haidong, additional, Kanis, John A, additional, Kassebaum, Nicholas, additional, Kawakami, Norito, additional, Khang, Young-Ho, additional, Khatibzadeh, Shahab, additional, Khoo, Jon-Paul, additional, Kok, Cindy, additional, Laden, Francine, additional, Lalloo, Ratilal, additional, Lan, Qing, additional, Lathlean, Tim, additional, Leasher, Janet L, additional, Leigh, James, additional, Li, Yang, additional, Lin, John Kent, additional, Lipshultz, Steven E, additional, London, Stephanie, additional, Lozano, Rafael, additional, Lu, Yuan, additional, Mak, Joelle, additional, Malekzadeh, Reza, additional, Mallinger, Leslie, additional, Marcenes, Wagner, additional, March, Lyn, additional, Marks, Robin, additional, Martin, Randall, additional, McGale, Paul, additional, McGrath, John, additional, Mehta, Sumi, additional, Memish, Ziad A, additional, Mensah, George A, additional, Merriman, Tony R, additional, Micha, Renata, additional, Michaud, Catherine, additional, Mishra, Vinod, additional, Hanafiah, Khayriyyah Mohd, additional, Mokdad, Ali A, additional, Morawska, Lidia, additional, Mozaffarian, Dariush, additional, Murphy, Tasha, additional, Naghavi, Mohsen, additional, Neal, Bruce, additional, Nelson, Paul K, additional, Nolla, Joan Miquel, additional, Norman, Rosana, additional, Olives, Casey, additional, Omer, Saad B, additional, Orchard, Jessica, additional, Osborne, Richard, additional, Ostro, Bart, additional, Page, Andrew, additional, Pandey, Kiran D, additional, Parry, Charles DH, additional, Passmore, Erin, additional, Patra, Jayadeep, additional, Pearce, Neil, additional, Pelizzari, Pamela M, additional, Petzold, Max, additional, Phillips, Michael R, additional, Pope, Dan, additional, Pope, C Arden, additional, Powles, John, additional, Rao, Mayuree, additional, Razavi, Homie, additional, Rehfuess, Eva A, additional, Rehm, Jürgen T, additional, Ritz, Beate, additional, Rivara, Frederick P, additional, Roberts, Thomas, additional, Robinson, Carolyn, additional, Rodriguez-Portales, Jose A, additional, Romieu, Isabelle, additional, Room, Robin, additional, Rosenfeld, Lisa C, additional, Roy, Ananya, additional, Rushton, Lesley, additional, Salomon, Joshua A, additional, Sampson, Uchechukwu, additional, Sanchez-Riera, Lidia, additional, Sanman, Ella, additional, Sapkota, Amir, additional, Seedat, Soraya, additional, Shi, Peilin, additional, Shield, Kevin, additional, Shivakoti, Rupak, additional, Singh, Gitanjali M, additional, Sleet, David A, additional, Smith, Emma, additional, Smith, Kirk R, additional, Stapelberg, Nicolas JC, additional, Steenland, Kyle, additional, Stöckl, Heidi, additional, Stovner, Lars Jacob, additional, Straif, Kurt, additional, Straney, Lahn, additional, Thurston, George D, additional, Tran, Jimmy H, additional, Van Dingenen, Rita, additional, van Donkelaar, Aaron, additional, Veerman, J Lennert, additional, Vijayakumar, Lakshmi, additional, Weintraub, Robert, additional, Weissman, Myrna M, additional, White, Richard A, additional, Whiteford, Harvey, additional, Wiersma, Steven T, additional, Wilkinson, James D, additional, Williams, Hywel C, additional, Williams, Warwick, additional, Wilson, Nicholas, additional, Woolf, Anthony D, additional, Yip, Paul, additional, Zielinski, Jan M, additional, Lopez, Alan D, additional, Murray, Christopher JL, additional, and Ezzati, Majid, additional
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- 2012
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42. Years lived with disability (YLDs) for 1160 sequelae of 289 diseases and injuries 1990–2010: a systematic analysis for the Global Burden of Disease Study 2010
- Author
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Vos, Theo, primary, Flaxman, Abraham D, additional, Naghavi, Mohsen, additional, Lozano, Rafael, additional, Michaud, Catherine, additional, Ezzati, Majid, additional, Shibuya, Kenji, additional, Salomon, Joshua A, additional, Abdalla, Safa, additional, Aboyans, Victor, additional, Abraham, Jerry, additional, Ackerman, Ilana, additional, Aggarwal, Rakesh, additional, Ahn, Stephanie Y, additional, Ali, Mohammed K, additional, AlMazroa, Mohammad A, additional, Alvarado, Miriam, additional, Anderson, H Ross, additional, Anderson, Laurie M, additional, Andrews, Kathryn G, additional, Atkinson, Charles, additional, Baddour, Larry M, additional, Bahalim, Adil N, additional, Barker-Collo, Suzanne, additional, Barrero, Lope H, additional, Bartels, David H, additional, Basáñez, Maria-Gloria, additional, Baxter, Amanda, additional, Bell, Michelle L, additional, Benjamin, Emelia J, additional, Bennett, Derrick, additional, Bernabé, Eduardo, additional, Bhalla, Kavi, additional, Bhandari, Bishal, additional, Bikbov, Boris, additional, Abdulhak, Aref Bin, additional, Birbeck, Gretchen, additional, Black, James A, additional, Blencowe, Hannah, additional, Blore, Jed D, additional, Blyth, Fiona, additional, Bolliger, Ian, additional, Bonaventure, Audrey, additional, Boufous, Soufiane, additional, Bourne, Rupert, additional, Boussinesq, Michel, additional, Braithwaite, Tasanee, additional, Brayne, Carol, additional, Bridgett, Lisa, additional, Brooker, Simon, additional, Brooks, Peter, additional, Brugha, Traolach S, additional, Bryan-Hancock, Claire, additional, Bucello, Chiara, additional, Buchbinder, Rachelle, additional, Buckle, Geoffrey, additional, Budke, Christine M, additional, Burch, Michael, additional, Burney, Peter, additional, Burstein, Roy, additional, Calabria, Bianca, additional, Campbell, Benjamin, additional, Canter, Charles E, additional, Carabin, Hélène, additional, Carapetis, Jonathan, additional, Carmona, Loreto, additional, Cella, Claudia, additional, Charlson, Fiona, additional, Chen, Honglei, additional, Cheng, Andrew Tai-Ann, additional, Chou, David, additional, Chugh, Sumeet S, additional, Coffeng, Luc E, additional, Colan, Steven D, additional, Colquhoun, Samantha, additional, Colson, K Ellicott, additional, Condon, John, additional, Connor, Myles D, additional, Cooper, Leslie T, additional, Corriere, Matthew, additional, Cortinovis, Monica, additional, de Vaccaro, Karen Courville, additional, Couser, William, additional, Cowie, Benjamin C, additional, Criqui, Michael H, additional, Cross, Marita, additional, Dabhadkar, Kaustubh C, additional, Dahiya, Manu, additional, Dahodwala, Nabila, additional, Damsere-Derry, James, additional, Danaei, Goodarz, additional, Davis, Adrian, additional, De Leo, Diego, additional, Degenhardt, Louisa, additional, Dellavalle, Robert, additional, Delossantos, Allyne, additional, Denenberg, Julie, additional, Derrett, Sarah, additional, Des Jarlais, Don C, additional, Dharmaratne, Samath D, additional, Dherani, Mukesh, additional, Diaz-Torne, Cesar, additional, Dolk, Helen, additional, Dorsey, E Ray, additional, Driscoll, Tim, additional, Duber, Herbert, additional, Ebel, Beth, additional, Edmond, Karen, additional, Elbaz, Alexis, additional, Ali, Suad Eltahir, additional, Erskine, Holly, additional, Erwin, Patricia J, additional, Espindola, Patricia, additional, Ewoigbokhan, Stalin E, additional, Farzadfar, Farshad, additional, Feigin, Valery, additional, Felson, David T, additional, Ferrari, Alize, additional, Ferri, Cleusa P, additional, Fèvre, Eric M, additional, Finucane, Mariel M, additional, Flaxman, Seth, additional, Flood, Louise, additional, Foreman, Kyle, additional, Forouzanfar, Mohammad H, additional, Fowkes, Francis Gerry R, additional, Franklin, Richard, additional, Fransen, Marlene, additional, Freeman, Michael K, additional, Gabbe, Belinda J, additional, Gabriel, Sherine E, additional, Gakidou, Emmanuela, additional, Ganatra, Hammad A, additional, Garcia, Bianca, additional, Gaspari, Flavio, additional, Gillum, Richard F, additional, Gmel, Gerhard, additional, Gosselin, Richard, additional, Grainger, Rebecca, additional, Groeger, Justina, additional, Guillemin, Francis, additional, Gunnell, David, additional, Gupta, Ramyani, additional, Haagsma, Juanita, additional, Hagan, Holly, additional, Halasa, Yara A, additional, Hall, Wayne, additional, Haring, Diana, additional, Haro, Josep Maria, additional, Harrison, James E, additional, Havmoeller, Rasmus, additional, Hay, Roderick J, additional, Higashi, Hideki, additional, Hill, Catherine, additional, Hoen, Bruno, additional, Hoffman, Howard, additional, Hotez, Peter J, additional, Hoy, Damian, additional, Huang, John J, additional, Ibeanusi, Sydney E, additional, Jacobsen, Kathryn H, additional, James, Spencer L, additional, Jarvis, Deborah, additional, Jasrasaria, Rashmi, additional, Jayaraman, Sudha, additional, Johns, Nicole, additional, Jonas, Jost B, additional, Karthikeyan, Ganesan, additional, Kassebaum, Nicholas, additional, Kawakami, Norito, additional, Keren, Andre, additional, Khoo, Jon-Paul, additional, King, Charles H, additional, Knowlton, Lisa Marie, additional, Kobusingye, Olive, additional, Koranteng, Adofo, additional, Krishnamurthi, Rita, additional, Lalloo, Ratilal, additional, Laslett, Laura L, additional, Lathlean, Tim, additional, Leasher, Janet L, additional, Lee, Yong Yi, additional, Leigh, James, additional, Lim, Stephen S, additional, Limb, Elizabeth, additional, Lin, John Kent, additional, Lipnick, Michael, additional, Lipshultz, Steven E, additional, Liu, Wei, additional, Loane, Maria, additional, Ohno, Summer Lockett, additional, Lyons, Ronan, additional, Ma, Jixiang, additional, Mabweijano, Jacqueline, additional, MacIntyre, Michael F, additional, Malekzadeh, Reza, additional, Mallinger, Leslie, additional, Manivannan, Sivabalan, additional, Marcenes, Wagner, additional, March, Lyn, additional, Margolis, David J, additional, Marks, Guy B, additional, Marks, Robin, additional, Matsumori, Akira, additional, Matzopoulos, Richard, additional, Mayosi, Bongani M, additional, McAnulty, John H, additional, McDermott, Mary M, additional, McGill, Neil, additional, McGrath, John, additional, Medina-Mora, Maria Elena, additional, Meltzer, Michele, additional, Memish, Ziad A, additional, Mensah, George A, additional, Merriman, Tony R, additional, Meyer, Ana-Claire, additional, Miglioli, Valeria, additional, Miller, Matthew, additional, Miller, Ted R, additional, Mitchell, Philip B, additional, Mocumbi, Ana Olga, additional, Moffitt, Terrie E, additional, Mokdad, Ali A, additional, Monasta, Lorenzo, additional, Montico, Marcella, additional, Moradi-Lakeh, Maziar, additional, Moran, Andrew, additional, Morawska, Lidia, additional, Mori, Rintaro, additional, Murdoch, Michele E, additional, Mwaniki, Michael K, additional, Naidoo, Kovin, additional, Nair, M Nathan, additional, Naldi, Luigi, additional, Narayan, KM Venkat, additional, Nelson, Paul K, additional, Nelson, Robert G, additional, Nevitt, Michael C, additional, Newton, Charles R, additional, Nolte, Sandra, additional, Norman, Paul, additional, Norman, Rosana, additional, O'Donnell, Martin, additional, O'Hanlon, Simon, additional, Olives, Casey, additional, Omer, Saad B, additional, Ortblad, Katrina, additional, Osborne, Richard, additional, Ozgediz, Doruk, additional, Page, Andrew, additional, Pahari, Bishnu, additional, Pandian, Jeyaraj Durai, additional, Rivero, Andrea Panozo, additional, Patten, Scott B, additional, Pearce, Neil, additional, Padilla, Rogelio Perez, additional, Perez-Ruiz, Fernando, additional, Perico, Norberto, additional, Pesudovs, Konrad, additional, Phillips, David, additional, Phillips, Michael R, additional, Pierce, Kelsey, additional, Pion, Sébastien, additional, Polanczyk, Guilherme V, additional, Polinder, Suzanne, additional, Pope, C Arden, additional, Popova, Svetlana, additional, Porrini, Esteban, additional, Pourmalek, Farshad, additional, Prince, Martin, additional, Pullan, Rachel L, additional, Ramaiah, Kapa D, additional, Ranganathan, Dharani, additional, Razavi, Homie, additional, Regan, Mathilda, additional, Rehm, Jürgen T, additional, Rein, David B, additional, Remuzzi, Guiseppe, additional, Richardson, Kathryn, additional, Rivara, Frederick P, additional, Roberts, Thomas, additional, Robinson, Carolyn, additional, De Leòn, Felipe Rodriguez, additional, Ronfani, Luca, additional, Room, Robin, additional, Rosenfeld, Lisa C, additional, Rushton, Lesley, additional, Sacco, Ralph L, additional, Saha, Sukanta, additional, Sampson, Uchechukwu, additional, Sanchez-Riera, Lidia, additional, Sanman, Ella, additional, Schwebel, David C, additional, Scott, James Graham, additional, Segui-Gomez, Maria, additional, Shahraz, Saeid, additional, Shepard, Donald S, additional, Shin, Hwashin, additional, Shivakoti, Rupak, additional, Silberberg, Donald, additional, Singh, David, additional, Singh, Gitanjali M, additional, Singh, Jasvinder A, additional, Singleton, Jessica, additional, Sleet, David A, additional, Sliwa, Karen, additional, Smith, Emma, additional, Smith, Jennifer L, additional, Stapelberg, Nicolas JC, additional, Steer, Andrew, additional, Steiner, Timothy, additional, Stolk, Wilma A, additional, Stovner, Lars Jacob, additional, Sudfeld, Christopher, additional, Syed, Sana, additional, Tamburlini, Giorgio, additional, Tavakkoli, Mohammad, additional, Taylor, Hugh R, additional, Taylor, Jennifer A, additional, Taylor, William J, additional, Thomas, Bernadette, additional, Thomson, W Murray, additional, Thurston, George D, additional, Tleyjeh, Imad M, additional, Tonelli, Marcello, additional, Towbin, Jeffrey A, additional, Truelsen, Thomas, additional, Tsilimbaris, Miltiadis K, additional, Ubeda, Clotilde, additional, Undurraga, Eduardo A, additional, van der Werf, Marieke J, additional, van Os, Jim, additional, Vavilala, Monica S, additional, Venketasubramanian, N, additional, Wang, Mengru, additional, Wang, Wenzhi, additional, Watt, Kerrianne, additional, Weatherall, David J, additional, Weinstock, Martin A, additional, Weintraub, Robert, additional, Weisskopf, Marc G, additional, Weissman, Myrna M, additional, White, Richard A, additional, Whiteford, Harvey, additional, Wiersma, Steven T, additional, Wilkinson, James D, additional, Williams, Hywel C, additional, Williams, Sean RM, additional, Witt, Emma, additional, Wolfe, Frederick, additional, Woolf, Anthony D, additional, Wulf, Sarah, additional, Yeh, Pon-Hsiu, additional, Zaidi, Anita KM, additional, Zheng, Zhi-Jie, additional, Zonies, David, additional, Lopez, Alan D, additional, and Murray, Christopher JL, additional
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- 2012
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- View/download PDF
43. Reduction of edge localized mode intensity on DIII-D by on-demand triggering with high frequency pellet injection and implications for ITER
- Author
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Steven J. Meitner, P.B. Snyder, C.J. Lasnier, Paul Parks, T.E. Evans, R.A. Moyer, Ezekial A Unterberg, G. T. A. Huijsmans, E. J. Strait, R.C. Isler, A.W. Leonard, A. Loarte, Nicolas Jc Commaux, M.E. Fenstermacher, Larry R. Baylor, Shimpei Futatani, T.H. Osborne, N.H. Brooks, T.C. Jernigan, and S.K. Combs
- Subjects
Physics ,Tokamak ,DIII-D ,law ,Divertor ,Pellets ,Plasma ,Magnetohydrodynamics ,Atomic physics ,Condensed Matter Physics ,Edge-localized mode ,Ballooning ,law.invention - Abstract
The injection of small deuterium pellets at high repetition rates up to 12× the natural edge localized mode (ELM) frequency has been used to trigger high-frequency ELMs in otherwise low natural ELM frequency H-mode deuterium discharges in the DIII-D tokamak [J. L. Luxon and L. G. Davis, Fusion Technol. 8, 441 (1985)]. The resulting pellet-triggered ELMs result in up to 12× lower energy and particle fluxes to the divertor than the natural ELMs. The plasma global energy confinement and density are not strongly affected by the pellet perturbations. The plasma core impurity density is strongly reduced with the application of the pellets. These experiments were performed with pellets injected from the low field side pellet in plasmas designed to match the ITER baseline configuration in shape and normalized β operation with input heating power just above the H-mode power threshold. Nonlinear MHD simulations of the injected pellets show that destabilization of ballooning modes by a local pressure perturbation is responsible for the pellet ELM triggering. This strongly reduced ELM intensity shows promise for exploitation in ITER to control ELM size while maintaining high plasma purity and performance.
- Published
- 2013
44. Control and dissipation of runaway electron beams created during rapid shutdown experiments in DIII-D
- Author
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M. A. Van Zeeland, David Humphreys, T.C. Jernigan, P. B. Parks, Nicolas Jc Commaux, N.H. Brooks, V.A. Izzo, A.N. James, J.M. Muñoz-Burgos, N.W. Eidietis, Dmitry Rudakov, Max E Austin, Jose Ramon Martin-Solis, E. J. Strait, A. Loarte, C.K. Tsui, J.H. Yu, J.C. Wesley, R.A. Moyer, J.A. Boedo, and E. M. Hollmann
- Subjects
Physics ,Nuclear and High Energy Physics ,Argon ,DIII-D ,chemistry.chemical_element ,Electron ,Plasma ,Dissipation ,Condensed Matter Physics ,Kinetic energy ,Distribution function ,chemistry ,Physics::Accelerator Physics ,Atomic physics ,Beam (structure) - Abstract
DIII-D experiments on rapid shutdown runaway electron (RE) beams have improved the understanding of the processes involved in RE beam control and dissipation. Improvements in RE beam feedback control have enabled stable confinement of RE beams out to the volt-second limit of the ohmic coil, as well as enabling a ramp down to zero current. Spectroscopic studies of the RE beam have shown that neutrals tend to be excluded from the RE beam centre. Measurements of the RE energy distribution function indicate a broad distribution with mean energy of order several MeV and peak energies of order 30?40?MeV. The distribution function appears more skewed towards low energies than expected from avalanche theory. The RE pitch angle appears fairly directed (????0.2) at high energies and more isotropic at lower energies (??100?keV). Collisional dissipation of RE beam current has been studied by massive gas injection of different impurities into RE beams; the equilibrium assimilation of these injected impurities appears to be reasonably well described by radial pressure balance between neutrals and ions. RE current dissipation following massive impurity injection is shown to be more rapid than expected from avalanche theory?this anomalous dissipation may be linked to enhanced radial diffusion caused by the significant quantity of high-Z impurities (typically argon) in the plasma. The final loss of RE beams to the wall has been studied: it was found that conversion of magnetic to kinetic energy is small for RE loss times smaller than the background plasma ohmic decay time of order 1?2?ms.
- Published
- 2013
45. Characterization of heat loads from mitigated and unmitigated vertical displacement events in DIII-D
- Author
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R.A. Pitts, Nicolas Jc Commaux, N.W. Eidietis, D.A. Humphreys, C.J. Lasnier, J. Wesley, Eric Hollmann, T. J. Jernigan, E. J. Strait, R.A. Moyer, J.G. Watkins, and M. Sugihara
- Subjects
Physics ,Toroid ,Tokamak ,DIII-D ,chemistry.chemical_element ,Plasma ,Mechanics ,Effective radiated power ,Condensed Matter Physics ,law.invention ,Neon ,chemistry ,law ,Vertical displacement ,Atomic physics ,Electric current - Abstract
Experiments have been conducted on the DIII-D tokamak to study the distribution and repeatability of heat loads and vessel currents resulting from vertical displacement events (VDEs). For unmitigated VDEs, the radiated power fraction appears to be of order 50%, with the remaining power dominantly conducted to the vessel walls. Shot-to-shot scatter in heat loads measured at one toroidal location is not large (
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- 2013
46. Visible imaging and spectroscopy of disruption runaway electrons in DIII-D
- Author
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D.A. Humphreys, Eric Hollmann, Nicolas Jc Commaux, A.N. James, R.A. Moyer, T. C. Jernigan, J.H. Yu, and N.W. Eidietis
- Subjects
Physics ,Spectrometer ,Astrophysics::High Energy Astrophysical Phenomena ,Bremsstrahlung ,Synchrotron radiation ,Electron ,Condensed Matter Physics ,Electromagnetic radiation ,Synchrotron ,law.invention ,law ,Physics::Accelerator Physics ,Plasma diagnostics ,Atomic physics ,Spectroscopy - Abstract
The first visible light images of synchrotron emission from disruption runaway electrons are presented. The forward-detected continuum radiation from runaways is identified as synchrotron emission by comparing two survey spectrometers and two visible fast cameras viewing in opposite toroidal directions. Analysis of the elongation of 2D synchrotron images of oval-shaped runaway beams indicates that the velocity pitch angle v⊥/v|| ranges from 0.1 to 0.2 for the detected electrons, with energies above 25 MeV. Analysis of synchrotron intensity from a camera indicates that the tail of the runaway energy distribution reaches energies up to 60 MeV, which agrees with 0D modeling of electron acceleration in the toroidal electric field generated during the current quench. A visible spectrometer provides an independent estimate of the upper limit of runaway electron energy which is roughly consistent with energy determined from camera data. Synchrotron spectra reveal that approximately 1% of the total post-thermal q...
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- 2013
47. Control of post-disruption runaway electron beams in DIII-D
- Author
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J.H. Yu, Nicolas Jc Commaux, M. A. Vanzeeland, R.A. Moyer, J.C. Wesley, E. J. Strait, N.W. Eidietis, D.A. Humphreys, T.C. Jernigan, and Eric Hollmann
- Subjects
Physics ,Tokamak ,Steady state ,Electron ,Mechanics ,Dissipation ,Condensed Matter Physics ,law.invention ,law ,Limiter ,Electric current ,Atomic physics ,Current (fluid) ,Beam (structure) - Abstract
Recent experiments in the DIII-D tokamak have demonstrated real-time control and dissipation of post-disruption runaway electron (RE) beams. In the event that disruption avoidance, control, and mitigation schemes fail to avoid or suppress RE generation, active control of the RE beam may be an important line of defense to prevent the rapid, localized deposition of RE beam energy onto vulnerable vessel sections. During and immediately after the current quench, excessive radial compression of the runaway beams is avoided by a combination of techniques, improving the likelihood of the beams surviving this dynamic period without a fast termination. Once stabilized, the runaway beams are held in a steady state (out to the ohmic flux limit) with the application of active plasma current and position controls. Beam interaction with the vessel wall is minimized by avoiding distinct thresholds for enhanced wall interaction at small and large radii, corresponding to inner wall and outer limiter interaction, respectively. Staying within the “safe zone” between those radial thresholds allows for the sustainment of long-lived, quiescent runaway beams. The total beam energy and runaway electron population are then dissipated gradually by a controlled ramp-down of the runaway current.
- Published
- 2012
48. Changes in particle transport as a result of resonant magnetic perturbations in DIII-D
- Author
-
W. M. Solomon, G. M. Staebler, H. Reimerdes, R.A. Moyer, T. L. Rhodes, M.E. Fenstermacher, E. J. Doyle, George McKee, Lei Zeng, Nicolas Jc Commaux, Oliver Schmitz, G. Wang, Saskia Mordijck, and Kenneth W Gentle
- Subjects
Shear (sheet metal) ,Physics ,DIII-D ,Turbulence ,Electric field ,ddc:530 ,Plasma ,Atomic physics ,Condensed Matter Physics ,Resonance (particle physics) ,Resonant magnetic perturbations ,Computational physics ,Magnetic field - Abstract
In this paper, we introduce the first direct perturbed particle transport measurements in resonant magnetic perturbation (RMP) H-mode plasmas. The perturbed particle transport increases as a result of application of RMP deep into the core. In the core, a large reduction in E × B shear to a value below the linear growth rate, in conjunction with increasing density fluctuations, is consistent with an increase in turbulent particle transport. In the edge, the changes in turbulent particle transport are less obvious. There is a clear correlation between the linear growth rates and the density fluctuations measured at different scales, but it is uncertain which is the cause and which is the consequence. © 2012 American Institute of Physics.
- Published
- 2012
49. Measurements of hard x-ray emission from runaway electrons in DIII-D
- Author
-
George Tynan, Eric Hollmann, Nicolas Jc Commaux, Paul Parks, J.C. Wesley, Max E Austin, R.J. La Haye, Todd Evans, D.A. Humphreys, A.N. James, N.W. Eidietis, J.H. Yu, Valerie Izzo, T.C. Jernigan, E. J. Strait, and A.W. Hyatt
- Subjects
Physics ,Nuclear and High Energy Physics ,Argon ,DIII-D ,Divertor ,chemistry.chemical_element ,Plasma ,Kink instability ,Condensed Matter Physics ,Instability ,chemistry ,Physics::Plasma Physics ,Physics::Space Physics ,Limiter ,Electric current ,Atomic physics - Abstract
The spatial distribution of runaway electron (RE) strikes to the wall during argon pellet-initiated rapid shutdown of diverted and limited plasma shapes in DIII-D is studied using a new array of hard x-ray (HXR) scintillators. Two plasma configurations were investigated: an elongated diverted H-mode and a low-elongation limited L-mode. HXR emission from MeV level REs generated during the argon pellet injection is observed during the thermal quench (TQ) in diverted discharges from REs lost into the divertor. In limiter discharges, this prompt TQ loss is reduced, suggesting improved TQ confinement of REs in this configuration. During the plateau phase when the plasma current is carried by REs, toroidally symmetric HXR emission from remaining confined REs is seen. Transient HXR bursts during this RE current plateau suggest the presence of a small level of wall losses due to the presence of an unidentified instability. Eventually, an abrupt final loss of the remaining RE current occurs. This final loss HXR emission shows a strong toroidal peaking and a consistent spatiotemporal evolution that suggests the development of a kink instability.
- Published
- 2011
50. Effect of applied toroidal electric field on the growth/decay of plateau-phase runaway electron currents in DIII-D
- Author
-
E. J. Strait, J.H. Yu, Eric Hollmann, N.H. Brooks, Paul Parks, D.A. Humphreys, N.W. Eidietis, Todd Evans, T.C. Jernigan, A.N. James, C.K. Tsui, R.C. Isler, J.C. Wesley, J. Munoz, and Nicolas Jc Commaux
- Subjects
Physics ,Nuclear and High Energy Physics ,Tokamak ,Toroid ,Argon ,DIII-D ,chemistry.chemical_element ,Electron ,Dissipation ,Condensed Matter Physics ,law.invention ,chemistry ,Physics::Plasma Physics ,law ,Electric field ,Astrophysics::Earth and Planetary Astrophysics ,Atomic physics ,Voltage - Abstract
Large relativistic runaway electron currents (0.1?0.5?MA) persisting for ~100?ms are created in the DIII-D tokamak during rapid discharge shut down caused by argon pellet injection. Slow upward and downward ramps in runaway currents were found in response to externally applied loop voltages. Comparison between the observed current growth/decay rate and the rate expected from the knock-on avalanche mechanism suggests that classical collisional dissipation of runaways alone cannot account for the measured growth/damping rates. It appears that a fairly constant anomalous dissipation rate of order 10?s?1 exists, possibly stemming from radial transport or direct orbit losses to the vessel walls, although the possibility of an apparent loss due to current profile shrinking cannot be ruled out at present.
- Published
- 2011
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