Search

Your search keyword '"Wijkamp, T."' showing total 32 results
Start Over Author "Wijkamp, T."
32 results on '"Wijkamp, T."'

1. 2D electron density profile evolution during detachment in Super-X divertor L-mode discharges on MAST-U

Author

Lonigro, N., Doyle, R. S., Verhaegh, K., Lipschultz, B., Moulton, D., Ryan, P., Allcock, J. S., Bowman, C., Harrison, J., Silburn, S., Theiler, C., Wijkamp, T. A., Team, the WPTE, and Team, MAST-U

Subjects
Physics - Plasma Physics
Abstract

2D electron density profiles obtained from coherence imaging spectroscopy in different MAST-U divertor conditions are compared. The data includes variations of strike point position, core electron density, and heating power. The improved performance of the long-legged divertors results in a lower electron density and particle flux at the target compared to configurations with smaller strike point major radius, while also being characterized by lower temperatures and deeper detachment. Comparisons against SOLPS simulations generally show good agreement in profile shape along and across the separatrix. The peaking of the electron density downstream of the detachment front is associated with significant neutral drag acting on the plasma flow.

Published
2024

2. First demonstration of Super-X divertor exhaust control for transient heat load management in compact fusion reactors

Author

Kool, B., Verhaegh, K., Derks, G. L., Wijkamp, T. A., Lonigro, N., Doyle, R., McArdle, G., Vincent, C., Lovell, J., Federici, F., Henderson, S. S., Osawa, R. T., Brida, D., Reimerdes, H., van Berkel, M., team, The EUROfusion tokamak exploitation, and team, the MAST-U

Subjects
Physics - Plasma Physics
Abstract

Nuclear fusion could offer clean, abundant energy. However, managing the immense power exhausted from the core fusion plasma towards the divertor remains a major challenge. This is compounded in emerging compact reactor designs which promise more cost-effective pathways towards commercial fusion energy. Alternative divertor configurations (ADCs) are a potential solution to this challenge. In this work, we demonstrate exhaust control in ADCs for the first time, on MAST-U. We employ a novel diagnostic strategy for the neutral gas buffer which shields the target. Our work shows that ADCs tackle key risks and uncertainties in realising fusion energy: 1) an enlarged operating window which 2) improves exhaust control through the absorption of transients which can remove the neutral shield and damage the divertor, 3) isolation of each divertor from other reactor regions, enabling combined control. This showcases real-world benefits of alternative divertors for effective heat load management and control in reactors.

Published
2024

3. First 2D electron density measurements using Coherence Imaging Spectroscopy in the MAST-U Super-X divertor

Author

Lonigro, N., Doyle, R., Allcock, J. S., Lipschultz, B., Verhaegh, K., Bowman, C., Brida, D., Harrison, J., Myatra, O., Silburn, S., Theiler, C., Wijkamp, T. A., Team, MAST-U, and Team, the EUROfusion Tokamak Exploitation

Subjects
Physics - Plasma Physics
Abstract

2D profiles of electron density and neutral temperature are inferred from multi-delay Coherence Imaging Spectroscopy data of divertor plasmas using a non-linear inversion technique. The inference is based on imaging the spectral line-broadening of Balmer lines and can differentiate between the Doppler and Stark broadening components by measuring the fringe contrast at multiple interferometric delays simultaneously. The model has been applied to images generated from simulated density profiles to evaluate its performance. Typical mean absolute errors of 30 percent are achieved, which are consistent with Monte Carlo uncertainty propagation accounting for noise, uncertainties in the calibrations, and in the model inputs. The analysis has been tested on experimental data from the MAST-U Super-X divertor, where it infers typical electron densities of 2-3 $10^{19}$ m$^{-3}$ and neutral temperatures of 0-2 eV during beam-heated L-mode discharges. The results are shown to be in reasonable agreement with the other available diagnostics.

Published
2024

4. Expulsion of runaway electrons using ECRH in the TCV tokamak

Author

Decker, J., Hoppe, M., Sheikh, U., Duval, B. P., Papp, G., Simons, L., Wijkamp, T., Cazabonne, J., Coda, S., Devlaminck, E., Ficker, O., Hellinga, R., Kumar, U., Savoye-Peysson, Y., Porte, L., Reux, C., Sommariva, C., Biwolé, A. Tema, Vincent, B., Votta, L., Team, the TCV, and Team, the EUROfusion Tokamak Exploitation

Subjects
Physics - Plasma Physics
Abstract

Runaway electrons (REs) are a concern for tokamak fusion reactors from discharge startup to termination. A sudden localized loss of a multi-megaampere RE beam can inflict severe damage to the first wall. Should a disruption occur, the existence of a RE seed may play a significant role in the formation of a RE beam and the magnitude of its current. The application of central electron cyclotron resonance heating (ECRH) in the Tokamak \`a Configuration Variable (TCV) reduces an existing RE seed population by up to three orders of magnitude within only a few hundred milliseconds. Applying ECRH before a disruption can also prevent the formation of a post-disruption RE beam in TCV where it would otherwise be expected. The RE expulsion rate and consequent RE current reduction are found to increase with applied ECRH power. Whereas central ECRH is effective in expelling REs, off-axis ECRH has a comparatively limited effect. A simple 0-D model for the evolution of the RE population is presented that explains the effective ECRH-induced RE expulsion results from the combined effects of increased electron temperature and enhanced RE transport.

Published
2024

5. Divertor shaping with neutral baffling as a solution to the tokamak power exhaust challenge

Author

Verhaegh, K., Harrison, J. R., Moulton, D., Lipschultz, B., Lonigro, N., Osborne, N., Ryan, P., Theiler, C., Wijkamp, T., Brida, D., Cowley, C., Derks, G., Doyle, R., Federici, F., Kool, B., Février, O., Hakola, A., Henderson, S., Reimerdes, H., Thornton, A. J., Vianello, N., Wischmeier, M., and Xiang, L.

Subjects
Physics - Plasma Physics
Abstract

Exhausting power from the hot fusion core to the plasma-facing components is one of the biggest challenges in fusion energy. The MAST Upgrade tokamak uniquely integrates strong containment of neutrals within the exhaust area (divertor) with extreme divertor shaping capability. By systematically altering the divertor shape, this study shows the strongest evidence to date that long-legged divertors with a high magnetic field gradient (total flux expansion) deliver key power exhaust benefits without adversely impacting the hot fusion core. These benefits are already achieved with relatively modest geometry adjustments that are more feasible to integrate in reactor designs. Benefits include reduced target heat loads and improved access to, and stability of, a neutral gas buffer that 'shields' the target and enhances power exhaust (detachment). Analysis and model comparisons shows these benefits are obtained by combining multiple shaping aspects: long-legged divertors have expanded plasma-neutral interaction volume that drive reductions in particle and power loads, while total flux expansion enhances detachment access and stability. Containing the neutrals in the exhaust area with physical structures further augments these shaping benefits. These results demonstrate strategic variation in the divertor geometry and magnetic topology is a potential solution to one of fusion's biggest challenges: power exhaust.

Published
2023

6. Investigations of atomic \& molecular processes of NBI-heated discharges in the MAST Upgrade Super-X divertor with implications for reactors

Author

Verhaegh, K., Harrison, J. R., Lipschultz, B., Lonigro, N., Kobussen, S., Moulton, D., Osborne, N., Ryan, P., Theiler, C., Wijkamp, T., Brida, D., Derks, G., Doyle, R., Federici, F., Hakola, A., Henderson, S., Kool, B., Newton, S., Osawa, R., Pope, X., Reimerdes, H., Vianello, N., and Wischmeier, M.

Subjects
Physics - Plasma Physics
Abstract

This experimental study presents an in-depth investigation of the performance of the MAST-U Super-X divertor during NBI-heated operation (up to 2.5 MW) focussing on volumetric ion sources and sinks as well as power losses during detachment. The particle balance and power loss analysis revealed the crucial role of Molecular Activated Recombination and Dissociation (MAR and MAD) ion sinks in divertor particle and power balance, which remain pronounced in the change from ohmic to higher power (NBI heated) L-mode conditions. The importance of MAR and MAD remains with double the absorbed NBI heating. MAD results in significant power dissipation (up to $\sim 20 \%$ of $P_{SOL}$), mostly in the cold ($T_e < 5$ eV) detached region. Theoretical and experimental evidence is found for the potential contribution of $D^-$ to MAR and MAD, which warrants further study. These results suggest that MAR and MAD can be relevant in higher power conditions than the ohmic conditions studied previously. Post-processing reactor-scale simulations shows that MAR and MAD can play a significant role in divertor physics and synthetic diagnostic signals of reactor-scale devices, which are currently underestimated in exhaust simulations. This raises implications for the accuracy of reactor-scale divertor simulations of particularly tightly baffled (alternative) divertor configurations.

Published
2023

7. Initial Fulcher band observations from high resolution spectroscopy in the MAST-U divertor

Author

Osborne, N., Verhaegh, K., Bowden, M. D., Wijkamp, T., Lonigro, N., Ryan, P., Pawelec, E., Lipschultz, B., Soukhanovskii, V., Biggelaar, T. van den, and team, the MAST-U

Subjects
Physics - Plasma Physics
Abstract

High resolution Fulcher band spectroscopy was used in the MAST-U divertors during Super-X and elongated conventional divertor density ramps with $\text{D}_{2}$ fuelling from the mid-plane high-field side. In the Super-X case (density ramp from Greenwald fraction 0.12 to 0.24), the upper divertor showed ground state rotational temperatures of the $\text{D}_{2}$ molecules increasing from $\sim$6000 K, starting at the detachment onset, to $\sim$9000 K during deepening detachment. This was correlated with the movement of the Fulcher emission region, which is correlated with the ionisation source. The increase in rotational temperature did not occur near the divertor entrance, where the plasma was still ionising. Qualitative agreement was obtained between the lower and upper divertor. Similar rotational temperatures were obtained in the elongated divertor before the detachment onset, although the increase in rotational temperature during detachment was less clearly observed as less deep detachment was obtained. %In the elongated conventional divertor there was some qualitative agreement of this effect impeded by low signal. The measured vibrational distribution of the upper Fulcher state (first four bands) does not agree with a ground state Boltzmann distribution but shows a different characteristic with an elevated population especially in the $\nu = 2$ and $\nu = 3$ bands. The populations of the $\nu = 2$ and $\nu = 3$ band relative to the $\nu = 0$ band are roughly proportional to the $\textit{rotational}$ temperature.

Published
2023

9. Tomographic reconstruction of the runaway distribution function in TCV using multispectral synchrotron images

Author

Wijkamp, T. A., Perek, A., Decker, J., Duval, B., Hoppe, M., Papp, G., Sheikh, U. A., Classen, I. G. J., Jaspers, R. J. E., team, the TCV, and team, the EUROfusion MST1

Subjects
Physics - Plasma Physics
Abstract

Synchrotron radiation observed in a quiescent TCV runaway discharge is studied using filtered camera images targeting three distinct wavelength intervals. Through the tomographic SART procedure the high momentum, high pitch angle part of the spatial and momentum distribution of these relativistic particles is reconstructed. Experimental estimates of the distribution are important for verification and refinement of formation-, decay- and transport-models underlying runaway avoidance and mitigation strategy design. Using a test distribution it is demonstrated that the inversion procedure provides estimates accurate to within a few tens of percent in the region of phase-space contributing most to the synchrotron image. We find that combining images filtered around different parts of the emission spectrum widens the probed part of momentum-space and reduces reconstruction errors. Next, the SART algorithm is used to obtain information on the spatiotemporal runaway momentum distribution in a selected TCV discharge. The momentum distribution is found to relax towards an avalanche-like exponentially decaying profile. Anomalously high pitch angles and a radial profile increasing towards the edge are found for the most strongly emitting particles in the distribution. Pitch angle scattering by toroidal magnetic field ripple is consistent with this picture. An alternative explanation is the presence of high frequency instabilities in combination with the formation of a runaway shell at the edge of the plasma., Comment: 18 pages, 13 figures, submitted to Nuclear Fusion

Published
2020
Full Text
View/download PDF

10. Benign termination of runaway electron beams on ASDEX Upgrade and TCV

Author

Sheikh, U, Decker, J, Hoppe, M, Pedrini, M, Sieglin, B, Simons, L, Cazabonne, J, Caloud, J, Cerovsky, J, Coda, S, Colandrea, C, Dal Molin, A, Duval, B, Ficker, O, Griener, M, Papp, G, Pautasso, G, Paz-Soldan, C, Reux, C, Tomesova, E, Wijkamp, T, Sheikh U., Decker J., Hoppe M., Pedrini M., Sieglin B., Simons L., Cazabonne J., Caloud J., Cerovsky J., Coda S., Colandrea C., Dal Molin A., Duval B., Ficker O., Griener M., Papp G., Pautasso G., Paz-Soldan C., Reux C., Tomesova E., Wijkamp T., Sheikh, U, Decker, J, Hoppe, M, Pedrini, M, Sieglin, B, Simons, L, Cazabonne, J, Caloud, J, Cerovsky, J, Coda, S, Colandrea, C, Dal Molin, A, Duval, B, Ficker, O, Griener, M, Papp, G, Pautasso, G, Paz-Soldan, C, Reux, C, Tomesova, E, Wijkamp, T, Sheikh U., Decker J., Hoppe M., Pedrini M., Sieglin B., Simons L., Cazabonne J., Caloud J., Cerovsky J., Coda S., Colandrea C., Dal Molin A., Duval B., Ficker O., Griener M., Papp G., Pautasso G., Paz-Soldan C., Reux C., Tomesova E., and Wijkamp T.

Abstract

This paper discusses the development of a benign termination scenario for runaway electron (RE) beams on ASDEX Upgrade and TCV. A systematic study revealed that a low electron density (n e) companion plasma was required to achieve a large MHD instability, which expelled the confined REs over a large wetted area and allowed for the conversion of magnetic energy to radiation. Control of the companion plasma ne was achieved via neutral pressure regulation and was agnostic to material injection method. The neutral pressure required for recombination was found to be dependent on impurity species, quantity and RE current. On TCV, n e increased at neutral pressures above 1 Pa, indicating that higher collisionality between the REs and neutrals may lead to an upper pressure limit. The conversion of magnetic energy to radiated energy was measured on both machines and a decrease in efficiency was observed at high neutral pressure on TCV. The benign termination technique was able to prevent any significant increase in maximum heat flux on AUG from 200 to 600 kA of RE current, highlighting the ability of this approach to handle fully formed RE beams.

Published
2024

11. Benign termination of runaway electron beams on ASDEX Upgrade and TCV

Author

Sheikh, U., Decker, J., Hoppe, Mathias, Pedrini, M., Sieglin, B., Simons, L., Cazabonne, J., Caloud, J., Cerovsky, J., Coda, S., Colandrea, C., Dal Molin, A., Duval, B., Ficker, O., Griener, M., Papp, G., Pautasso, G., Paz-Soldan, C., Reux, C., Tomesova, E., Wijkamp, T., Sheikh, U., Decker, J., Hoppe, Mathias, Pedrini, M., Sieglin, B., Simons, L., Cazabonne, J., Caloud, J., Cerovsky, J., Coda, S., Colandrea, C., Dal Molin, A., Duval, B., Ficker, O., Griener, M., Papp, G., Pautasso, G., Paz-Soldan, C., Reux, C., Tomesova, E., and Wijkamp, T.

Abstract

This paper discusses the development of a benign termination scenario for runaway electron (RE) beams on ASDEX Upgrade and TCV. A systematic study revealed that a low electron density (n e) companion plasma was required to achieve a large MHD instability, which expelled the confined REs over a large wetted area and allowed for the conversion of magnetic energy to radiation. Control of the companion plasma ne was achieved via neutral pressure regulation and was agnostic to material injection method. The neutral pressure required for recombination was found to be dependent on impurity species, quantity and RE current. On TCV, n e increased at neutral pressures above 1 Pa, indicating that higher collisionality between the REs and neutrals may lead to an upper pressure limit. The conversion of magnetic energy to radiated energy was measured on both machines and a decrease in efficiency was observed at high neutral pressure on TCV. The benign termination technique was able to prevent any significant increase in maximum heat flux on AUG from 200 to 600 kA of RE current, highlighting the ability of this approach to handle fully formed RE beams., QC 20240201

Published
2024
Full Text
View/download PDF

12. Resonant interaction between runaway electrons and the toroidal magnetic field ripple in TCV

Author

Wijkamp, T. A., Hoppe, Mathias, Decker, J., Duval, B. P., Perek, A., Sheikh, U., Classen, I. G. J., Jaspers, R. J. E., Wijkamp, T. A., Hoppe, Mathias, Decker, J., Duval, B. P., Perek, A., Sheikh, U., Classen, I. G. J., and Jaspers, R. J. E.

Abstract

This work explains the anomalously high runaway electron (RE) pitch angles inferred in the flat-top of dedicated Tokamak a Configuration Variable (TCV) experiments. Kinetic modelling shows that the resonant interaction between the gyromotion of the electrons and the toroidal magnetic field ripple will give rise to strong pitch angle scattering in TCV. The resulting increase in synchrotron radiation power losses acts as a RE energy barrier. These observations are tested experimentally by a magnetic field ramp-down, which gradually reduces the resonant parallel momentum at which the REs interact with the ripple. Resulting changes in synchrotron emission geometry and intensity are observed using three multi-spectral camera imaging systems, viewing the RE beam at distinct spatial angles in multiple wavelength ranges. Experimental reconstructions of the RE distribution in momentum- and real-space are consistent with kinetic model predictions., QC 20231211

Published
2024
Full Text
View/download PDF

13. Demonstration of a sparse sensor placement technique to the limited diagnostic set in a fusion power plant

Author

the TCV team, Raukema, J., Bosman, T.O.S.J., Classen, I.G.J., Wijkamp, T. A., Perek, A., Derks, G.L., Koenders, J.T.W., Martinelli, L., Jaspers, R.J.E., the TCV team, Raukema, J., Bosman, T.O.S.J., Classen, I.G.J., Wijkamp, T. A., Perek, A., Derks, G.L., Koenders, J.T.W., Martinelli, L., and Jaspers, R.J.E.

Abstract

DEMO will have a limited diagnostic set for optimization of reactor performance, and limited diagnostic coverage due to challenging reactor conditions. This poses challenges for control, especially for detachment control which is planned to be performed with a limited set of spectroscopic lines-of-sight. To demonstrate mitigation of the coverage problem, we have implemented a sparse sensor placement technique on TCV for the case of spectroscopy. Experimental CIII 2D emissivity profiles from the MANTIS multispectral imaging system at TCV are used to create a synthetic spectroscopy system, with DEMO-relevant lines-of-sight. This synthetic diagnostic is validated through comparison with spectroscopic measurements in TCV. The sparse sensor placement algorithm takes as input the radiance calculated for a large set of lines-of-sight, resolved in time. It provides a method to reconstruct an emission profile along the divertor leg based on measurements from only a few lines-of-sight. We demonstrate that it is feasible to use a calibration based on either experimental data or simulated emissivities from SOLPS-ITER. As a result, for DEMO, the line-of-sight selection and a mathematical basis for reconstruction can be obtained before the reactor is turned on. The sparse sensor placement method can also be applied to estimate other physical quantities from emission measurements, if they have a one-to-one relationship with the shape of the emission profile along the divertor leg. As an example, the peak target current density obtained with Langmuir probes can be reconstructed using spectroscopy measurements. Lastly, the geometry of the lines-of-sight plays an important role in proper emission profile reconstruction. It should be tailor-made to the used magnetic configuration to measure the emission profile accurately, and the technique described here offers a route for performing this optimization.

Published
2024

14. Resonant interaction between runaway electrons and the toroidal magnetic field ripple in TCV

Author

the TCV team, Wijkamp, T., Perek, A., Classen, I., Jaspers, R., the TCV team, Wijkamp, T., Perek, A., Classen, I., and Jaspers, R.

Abstract

This work explains the anomalously high runaway electron (RE) pitch angles inferred in the flat-top of dedicated Tokamak à Configuration Variable (TCV) experiments. Kinetic modelling shows that the resonant interaction between the gyromotion of the electrons and the toroidal magnetic field ripple will give rise to strong pitch angle scattering in TCV. The resulting increase in synchrotron radiation power losses acts as a RE energy barrier. These observations are tested experimentally by a magnetic field ramp-down, which gradually reduces the resonant parallel momentum at which the REs interact with the ripple. Resulting changes in synchrotron emission geometry and intensity are observed using three multi-spectral camera imaging systems, viewing the RE beam at distinct spatial angles in multiple wavelength ranges. Experimental reconstructions of the RE distribution in momentum- and real-space are consistent with kinetic model predictions.

Published
2024

15. The X-Point radiating regime at ASDEX Upgrade and TCV

Author

Bernert, M, Wiesen, S, Fevrier, O, Kallenbach, A, Koenders, J, Sieglin, B, Stroth, U, Bosman, T, Brida, D, Cavedon, M, David, P, Dunne, M, Henderson, S, Kool, B, Lunt, T, Mcdermott, R, Pan, O, Perek, A, Reimerdes, H, Sheikh, U, Theiler, C, van Berkel, M, Wijkamp, T, Wischmeier, M, Bernert M., Wiesen S., Fevrier O., Kallenbach A., Koenders J. T. W., Sieglin B., Stroth U., Bosman T. O. S. J., Brida D., Cavedon M., David P., Dunne M. G., Henderson S., Kool B., Lunt T., McDermott R. M., Pan O., Perek A., Reimerdes H., Sheikh U., Theiler C., van Berkel M., Wijkamp T., Wischmeier M., Bernert, M, Wiesen, S, Fevrier, O, Kallenbach, A, Koenders, J, Sieglin, B, Stroth, U, Bosman, T, Brida, D, Cavedon, M, David, P, Dunne, M, Henderson, S, Kool, B, Lunt, T, Mcdermott, R, Pan, O, Perek, A, Reimerdes, H, Sheikh, U, Theiler, C, van Berkel, M, Wijkamp, T, Wischmeier, M, Bernert M., Wiesen S., Fevrier O., Kallenbach A., Koenders J. T. W., Sieglin B., Stroth U., Bosman T. O. S. J., Brida D., Cavedon M., David P., Dunne M. G., Henderson S., Kool B., Lunt T., McDermott R. M., Pan O., Perek A., Reimerdes H., Sheikh U., Theiler C., van Berkel M., Wijkamp T., and Wischmeier M.

Abstract

Future fusion reactors require a safe, steady-state divertor operation. With deep divertor detachment, which is typically induced by impurity seeding, the radiation concentrates in a small region at the X-point or on closed flux surfaces above the X-point. This so-called X-point radiator (XPR) moves further inside the confined region with increasing seeding and the location can be actively controlled. At AUG, the parameter space for operation with an XPR was significantly extended, using active feedback on the XPR location. The XPR is observed in nearly the whole operational space of AUG in the high-densities or high collisionality regime. ELM suppression is consistently observed in all cases where the XPR was moved to a significant height above the X-point. Direct measurements of density and temperature from the region around the XPR using the new divertor Thomson scattering system at AUG indicate that the temperature at the location of the XPR remains high (>30eV) and only the region towards the X-point cools down further. In this cold XPR core, the temperature reduces to about 1eV. An XPR is also observed in TCV by the injection of nitrogen as extrinsic impurity. This highlights that the wall material (W for AUG, C for TCV) or machine size does not play a significant role for the existence of the regime. However, the scenario appears to be less stable in TCV. First experiments show the necessity of an active control for the XPR: Depending on the wall conditions and the nitrogen wall storage, the required nitrogen seeding level to achieve an XPR changes. Both, the low temperatures measured radially outside of the radiation zone at AUG, and the lower stability of the XPR regime at TCV with the presence of carbon are consistent with the predictions of a one-dimensional model of the XPR. However, the model would predict the development of the cold XPR core, and significant radiation at the X-point might already exist before reaching this cold temperature solution.

Published
2023

17. Overview of the TCV tokamak experimental programme

Author

Reimerdes, H, Agostini, M, Alessi, E, Alberti, S, Andrebe, Y, Arnichand, H, Balbin, J, Bagnato, F, Baquero-Ruiz, M, Bernert, M, Bin, W, Blanchard, P, Blanken, T, Boedo, J, Brida, D, Brunner, S, Bogar, C, Bogar, O, Bolzonella, T, Bombarda, F, Bouquey, F, Bowman, C, Brunetti, D, Buermans, J, Bufferand, H, Calacci, L, Camenen, Y, Carli, S, Carnevale, D, Carpanese, F, Causa, F, Cavalier, J, Cavedon, M, Cazabonne, J, Cerovsky, J, Chandra, R, Chandrarajan Jayalekshmi, A, Chellai, O, Chmielewski, P, Choi, D, Ciraolo, G, Classen, I, Coda, S, Colandrea, C, Dal Molin, A, David, P, De Baar, M, Decker, J, Dekeyser, W, De Oliveira, H, Douai, D, Dreval, M, Dunne, M, Duval, B, Elmore, S, Embreus, O, Eriksson, F, Faitsch, M, Falchetto, G, Farnik, M, Fasoli, A, Fedorczak, N, Felici, F, Fevrier, O, Ficker, O, Fil, A, Fontana, M, Fransson, E, Frassinetti, L, Furno, I, Gahle, D, Galassi, D, Galazka, K, Galperti, C, Garavaglia, S, Garcia-Munoz, M, Geiger, B, Giacomin, M, Giruzzi, G, Gobbin, M, Golfinopoulos, T, Goodman, T, Gorno, S, Granucci, G, Graves, J, Griener, M, Gruca, M, Gyergyek, T, Haelterman, R, Hakola, A, Han, W, Happel, T, Harrer, G, Harrison, J, Henderson, S, Hogeweij, G, Hogge, J, Hoppe, M, Horacek, J, Huang, Z, Iantchenko, A, Innocente, P, Insulander Bjork, K, Ionita-Schrittweiser, C, Isliker, H, Jardin, A, Jaspers, R, Karimov, R, Karpushov, A, Kazakov, Y, Komm, M, Kong, M, Kovacic, J, Krutkin, O, Kudlacek, O, Kumar, U, Kwiatkowski, R, Labit, B, Laguardia, L, Lammers, J, Laribi, E, Laszynska, E, Lazaros, A, Linder, O, Linehan, B, Lipschultz, B, Llobet, X, Loizu, J, Lunt, T, Macusova, E, Marandet, Y, Maraschek, M, Marceca, G, Marchetto, C, Marchioni, S, Marmar, E, Martin, Y, Martinelli, L, Matos, F, Maurizio, R, Mayoral, M, Mazon, D, Menkovski, V, Merle, A, Merlo, G, Meyer, H, Mikszuta-Michalik, K, Molina Cabrera, P, Morales, J, Moret, J, Moro, A, Moulton, D, Muhammed, H, Myatra, O, Mykytchuk, D, Napoli, F, Nem, R, Nielsen, A, Nocente, M, Nowak, S, Offeddu, N, Olsen, J, Orsitto, F, Pan, O, Papp, G, Pau, A, Perek, A, Pesamosca, F, Peysson, Y, Pigatto, L, Piron, C, Poradzinski, M, Porte, L, Putterich, T, Rabinski, M, Raj, H, Rasmussen, J, Ratta, G, Ravensbergen, T, Ricci, D, Ricci, P, Rispoli, N, Riva, F, Rivero-Rodriguez, J, Salewski, M, Sauter, O, Schmidt, B, Schrittweiser, R, Sharapov, S, Sheikh, U, Sieglin, B, Silva, M, Smolders, A, Snicker, A, Sozzi, C, Spolaore, M, Stagni, A, Stipani, L, Sun, G, Tala, T, Tamain, P, Tanaka, K, Tema Biwole, A, Terranova, D, Terry, J, Testa, D, Theiler, C, Thornton, A, Thrysoe, A, Torreblanca, H, Tsui, C, Vaccaro, D, Vallar, M, Van Berkel, M, Van Eester, D, Van Kampen, R, Van Mulders, S, Verhaegh, K, Verhaeghe, T, Vianello, N, Villone, F, Viezzer, E, Vincent, B, Voitsekhovitch, I, Vu, N, Walkden, N, Wauters, T, Weisen, H, Wendler, N, Wensing, M, Widmer, F, Wiesen, S, Wischmeier, M, Wijkamp, T, Wunderlich, D, Wuthrich, C, Yanovskiy, V, Zebrowski, J, Reimerdes H., Agostini M., Alessi E., Alberti S., Andrebe Y., Arnichand H., Balbin J., Bagnato F., Baquero-Ruiz M., Bernert M., Bin W., Blanchard P., Blanken T. C., Boedo J. A., Brida D., Brunner S., Bogar C., Bogar O., Bolzonella T., Bombarda F., Bouquey F., Bowman C., Brunetti D., Buermans J., Bufferand H., Calacci L., Camenen Y., Carli S., Carnevale D., Carpanese F., Causa F., Cavalier J., Cavedon M., Cazabonne J. A., Cerovsky J., Chandra R., Chandrarajan Jayalekshmi A., Chellai O., Chmielewski P., Choi D., Ciraolo G., Classen I. G. J., Coda S., Colandrea C., Dal Molin A., David P., De Baar M. R., Decker J., Dekeyser W., De Oliveira H., Douai D., Dreval M., Dunne M. G., Duval B. P., Elmore S., Embreus O., Eriksson F., Faitsch M., Falchetto G., Farnik M., Fasoli A., Fedorczak N., Felici F., Fevrier O., Ficker O., Fil A., Fontana M., Fransson E., Frassinetti L., Furno I., Gahle D. S., Galassi D., Galazka K., Galperti C., Garavaglia S., Garcia-Munoz M., Geiger B., Giacomin M., Giruzzi G., Gobbin M., Golfinopoulos T., Goodman T., Gorno S., Granucci G., Graves J. P., Griener M., Gruca M., Gyergyek T., Haelterman R., Hakola A., Han W., Happel T., Harrer G., Harrison J. R., Henderson S., Hogeweij G. M. D., Hogge J. -P., Hoppe M., Horacek J., Huang Z., Iantchenko A., Innocente P., Insulander Bjork K., Ionita-Schrittweiser C., Isliker H., Jardin A., Jaspers R. J. E., Karimov R., Karpushov A. N., Kazakov Y., Komm M., Kong M., Kovacic J., Krutkin O., Kudlacek O., Kumar U., Kwiatkowski R., Labit B., Laguardia L., Lammers J. T., Laribi E., Laszynska E., Lazaros A., Linder O., Linehan B., Lipschultz B., Llobet X., Loizu J., Lunt T., Macusova E., Marandet Y., Maraschek M., Marceca G., Marchetto C., Marchioni S., Marmar E. S., Martin Y., Martinelli L., Matos F., Maurizio R., Mayoral M. -L., Mazon D., Menkovski V., Merle A., Merlo G., Meyer H., Mikszuta-Michalik K., Molina Cabrera P. A., Morales J., Moret J. -M., Moro A., Moulton D., Muhammed H., Myatra O., Mykytchuk D., Napoli F., Nem R. D., Nielsen A. H., Nocente M., Nowak S., Offeddu N., Olsen J., Orsitto F. P., Pan O., Papp G., Pau A., Perek A., Pesamosca F., Peysson Y., Pigatto L., Piron C., Poradzinski M., Porte L., Putterich T., Rabinski M., Raj H., Rasmussen J. J., Ratta G. A., Ravensbergen T., Ricci D., Ricci P., Rispoli N., Riva F., Rivero-Rodriguez J. F., Salewski M., Sauter O., Schmidt B. S., Schrittweiser R., Sharapov S., Sheikh U. A., Sieglin B., Silva M., Smolders A., Snicker A., Sozzi C., Spolaore M., Stagni A., Stipani L., Sun G., Tala T., Tamain P., Tanaka K., Tema Biwole A., Terranova D., Terry J. L., Testa D., Theiler C., Thornton A., Thrysoe A., Torreblanca H., Tsui C. K., Vaccaro D., Vallar M., Van Berkel M., Van Eester D., Van Kampen R. J. R., Van Mulders S., Verhaegh K., Verhaeghe T., Vianello N., Villone F., Viezzer E., Vincent B., Voitsekhovitch I., Vu N. M. T., Walkden N., Wauters T., Weisen H., Wendler N., Wensing M., Widmer F., Wiesen S., Wischmeier M., Wijkamp T. A., Wunderlich D., Wuthrich C., Yanovskiy V., Zebrowski J., Reimerdes, H, Agostini, M, Alessi, E, Alberti, S, Andrebe, Y, Arnichand, H, Balbin, J, Bagnato, F, Baquero-Ruiz, M, Bernert, M, Bin, W, Blanchard, P, Blanken, T, Boedo, J, Brida, D, Brunner, S, Bogar, C, Bogar, O, Bolzonella, T, Bombarda, F, Bouquey, F, Bowman, C, Brunetti, D, Buermans, J, Bufferand, H, Calacci, L, Camenen, Y, Carli, S, Carnevale, D, Carpanese, F, Causa, F, Cavalier, J, Cavedon, M, Cazabonne, J, Cerovsky, J, Chandra, R, Chandrarajan Jayalekshmi, A, Chellai, O, Chmielewski, P, Choi, D, Ciraolo, G, Classen, I, Coda, S, Colandrea, C, Dal Molin, A, David, P, De Baar, M, Decker, J, Dekeyser, W, De Oliveira, H, Douai, D, Dreval, M, Dunne, M, Duval, B, Elmore, S, Embreus, O, Eriksson, F, Faitsch, M, Falchetto, G, Farnik, M, Fasoli, A, Fedorczak, N, Felici, F, Fevrier, O, Ficker, O, Fil, A, Fontana, M, Fransson, E, Frassinetti, L, Furno, I, Gahle, D, Galassi, D, Galazka, K, Galperti, C, Garavaglia, S, Garcia-Munoz, M, Geiger, B, Giacomin, M, Giruzzi, G, Gobbin, M, Golfinopoulos, T, Goodman, T, Gorno, S, Granucci, G, Graves, J, Griener, M, Gruca, M, Gyergyek, T, Haelterman, R, Hakola, A, Han, W, Happel, T, Harrer, G, Harrison, J, Henderson, S, Hogeweij, G, Hogge, J, Hoppe, M, Horacek, J, Huang, Z, Iantchenko, A, Innocente, P, Insulander Bjork, K, Ionita-Schrittweiser, C, Isliker, H, Jardin, A, Jaspers, R, Karimov, R, Karpushov, A, Kazakov, Y, Komm, M, Kong, M, Kovacic, J, Krutkin, O, Kudlacek, O, Kumar, U, Kwiatkowski, R, Labit, B, Laguardia, L, Lammers, J, Laribi, E, Laszynska, E, Lazaros, A, Linder, O, Linehan, B, Lipschultz, B, Llobet, X, Loizu, J, Lunt, T, Macusova, E, Marandet, Y, Maraschek, M, Marceca, G, Marchetto, C, Marchioni, S, Marmar, E, Martin, Y, Martinelli, L, Matos, F, Maurizio, R, Mayoral, M, Mazon, D, Menkovski, V, Merle, A, Merlo, G, Meyer, H, Mikszuta-Michalik, K, Molina Cabrera, P, Morales, J, Moret, J, Moro, A, Moulton, D, Muhammed, H, Myatra, O, Mykytchuk, D, Napoli, F, Nem, R, Nielsen, A, Nocente, M, Nowak, S, Offeddu, N, Olsen, J, Orsitto, F, Pan, O, Papp, G, Pau, A, Perek, A, Pesamosca, F, Peysson, Y, Pigatto, L, Piron, C, Poradzinski, M, Porte, L, Putterich, T, Rabinski, M, Raj, H, Rasmussen, J, Ratta, G, Ravensbergen, T, Ricci, D, Ricci, P, Rispoli, N, Riva, F, Rivero-Rodriguez, J, Salewski, M, Sauter, O, Schmidt, B, Schrittweiser, R, Sharapov, S, Sheikh, U, Sieglin, B, Silva, M, Smolders, A, Snicker, A, Sozzi, C, Spolaore, M, Stagni, A, Stipani, L, Sun, G, Tala, T, Tamain, P, Tanaka, K, Tema Biwole, A, Terranova, D, Terry, J, Testa, D, Theiler, C, Thornton, A, Thrysoe, A, Torreblanca, H, Tsui, C, Vaccaro, D, Vallar, M, Van Berkel, M, Van Eester, D, Van Kampen, R, Van Mulders, S, Verhaegh, K, Verhaeghe, T, Vianello, N, Villone, F, Viezzer, E, Vincent, B, Voitsekhovitch, I, Vu, N, Walkden, N, Wauters, T, Weisen, H, Wendler, N, Wensing, M, Widmer, F, Wiesen, S, Wischmeier, M, Wijkamp, T, Wunderlich, D, Wuthrich, C, Yanovskiy, V, Zebrowski, J, Reimerdes H., Agostini M., Alessi E., Alberti S., Andrebe Y., Arnichand H., Balbin J., Bagnato F., Baquero-Ruiz M., Bernert M., Bin W., Blanchard P., Blanken T. C., Boedo J. A., Brida D., Brunner S., Bogar C., Bogar O., Bolzonella T., Bombarda F., Bouquey F., Bowman C., Brunetti D., Buermans J., Bufferand H., Calacci L., Camenen Y., Carli S., Carnevale D., Carpanese F., Causa F., Cavalier J., Cavedon M., Cazabonne J. A., Cerovsky J., Chandra R., Chandrarajan Jayalekshmi A., Chellai O., Chmielewski P., Choi D., Ciraolo G., Classen I. G. J., Coda S., Colandrea C., Dal Molin A., David P., De Baar M. R., Decker J., Dekeyser W., De Oliveira H., Douai D., Dreval M., Dunne M. G., Duval B. P., Elmore S., Embreus O., Eriksson F., Faitsch M., Falchetto G., Farnik M., Fasoli A., Fedorczak N., Felici F., Fevrier O., Ficker O., Fil A., Fontana M., Fransson E., Frassinetti L., Furno I., Gahle D. S., Galassi D., Galazka K., Galperti C., Garavaglia S., Garcia-Munoz M., Geiger B., Giacomin M., Giruzzi G., Gobbin M., Golfinopoulos T., Goodman T., Gorno S., Granucci G., Graves J. P., Griener M., Gruca M., Gyergyek T., Haelterman R., Hakola A., Han W., Happel T., Harrer G., Harrison J. R., Henderson S., Hogeweij G. M. D., Hogge J. -P., Hoppe M., Horacek J., Huang Z., Iantchenko A., Innocente P., Insulander Bjork K., Ionita-Schrittweiser C., Isliker H., Jardin A., Jaspers R. J. E., Karimov R., Karpushov A. N., Kazakov Y., Komm M., Kong M., Kovacic J., Krutkin O., Kudlacek O., Kumar U., Kwiatkowski R., Labit B., Laguardia L., Lammers J. T., Laribi E., Laszynska E., Lazaros A., Linder O., Linehan B., Lipschultz B., Llobet X., Loizu J., Lunt T., Macusova E., Marandet Y., Maraschek M., Marceca G., Marchetto C., Marchioni S., Marmar E. S., Martin Y., Martinelli L., Matos F., Maurizio R., Mayoral M. -L., Mazon D., Menkovski V., Merle A., Merlo G., Meyer H., Mikszuta-Michalik K., Molina Cabrera P. A., Morales J., Moret J. -M., Moro A., Moulton D., Muhammed H., Myatra O., Mykytchuk D., Napoli F., Nem R. D., Nielsen A. H., Nocente M., Nowak S., Offeddu N., Olsen J., Orsitto F. P., Pan O., Papp G., Pau A., Perek A., Pesamosca F., Peysson Y., Pigatto L., Piron C., Poradzinski M., Porte L., Putterich T., Rabinski M., Raj H., Rasmussen J. J., Ratta G. A., Ravensbergen T., Ricci D., Ricci P., Rispoli N., Riva F., Rivero-Rodriguez J. F., Salewski M., Sauter O., Schmidt B. S., Schrittweiser R., Sharapov S., Sheikh U. A., Sieglin B., Silva M., Smolders A., Snicker A., Sozzi C., Spolaore M., Stagni A., Stipani L., Sun G., Tala T., Tamain P., Tanaka K., Tema Biwole A., Terranova D., Terry J. L., Testa D., Theiler C., Thornton A., Thrysoe A., Torreblanca H., Tsui C. K., Vaccaro D., Vallar M., Van Berkel M., Van Eester D., Van Kampen R. J. R., Van Mulders S., Verhaegh K., Verhaeghe T., Vianello N., Villone F., Viezzer E., Vincent B., Voitsekhovitch I., Vu N. M. T., Walkden N., Wauters T., Weisen H., Wendler N., Wensing M., Widmer F., Wiesen S., Wischmeier M., Wijkamp T. A., Wunderlich D., Wuthrich C., Yanovskiy V., and Zebrowski J.

Abstract

The tokamak à configuration variable (TCV) continues to leverage its unique shaping capabilities, flexible heating systems and modern control system to address critical issues in preparation for ITER and a fusion power plant. For the 2019-20 campaign its configurational flexibility has been enhanced with the installation of removable divertor gas baffles, its diagnostic capabilities with an extensive set of upgrades and its heating systems with new dual frequency gyrotrons. The gas baffles reduce coupling between the divertor and the main chamber and allow for detailed investigations on the role of fuelling in general and, together with upgraded boundary diagnostics, test divertor and edge models in particular. The increased heating capabilities broaden the operational regime to include Te/Ti ∼1 and have stimulated refocussing studies from L-mode to H-mode across a range of research topics. ITER baseline parameters were reached in type-I ELMy H-modes and alternative regimes with 'small' (or no) ELMs explored. Most prominently, negative triangularity was investigated in detail and confirmed as an attractive scenario with H-mode level core confinement but an L-mode edge. Emphasis was also placed on control, where an increased number of observers, actuators and control solutions became available and are now integrated into a generic control framework as will be needed in future devices. The quantity and quality of results of the 2019-20 TCV campaign are a testament to its successful integration within the European research effort alongside a vibrant domestic programme and international collaborations.

Published
2022

18. The X-Point radiating regime at ASDEX Upgrade and TCV

Author

Bernert, M., primary, Wiesen, S., additional, Février, O., additional, Kallenbach, A., additional, Koenders, J.T.W., additional, Sieglin, B., additional, Stroth, U., additional, Bosman, T.O.S.J., additional, Brida, D., additional, Cavedon, M., additional, David, P., additional, Dunne, M.G., additional, Henderson, S., additional, Kool, B., additional, Lunt, T., additional, McDermott, R.M., additional, Pan, O., additional, Perek, A., additional, Reimerdes, H., additional, Sheikh, U., additional, Theiler, C., additional, van Berkel, M., additional, Wijkamp, T., additional, and Wischmeier, M., additional

Published
2023
Full Text
View/download PDF

19. Runaway electron dynamics in the Tokamak à Configuration Variable

Author

Hoppe, Mathias, Decker, J., Sheikh, U., Wijkamp, T., Cazabonne, J., Duval, B. P., Papp, G., Perek, A., Peysson, Y., Simons, L., Tema-Biwole, A., Vincent, B., Votta, L., Hoppe, Mathias, Decker, J., Sheikh, U., Wijkamp, T., Cazabonne, J., Duval, B. P., Papp, G., Perek, A., Peysson, Y., Simons, L., Tema-Biwole, A., Vincent, B., and Votta, L.

Abstract

Part of ISBN 9781713898672QC 20240716

Published
2023

20. The role of plasma-atom and molecule interactions on power & particle balance during detachment on the MAST Upgrade Super-X divertor

Author

MAST Upgrade team, Verhaegh, K., Kobussen, S., Wijkamp, T., Kool, B., MAST Upgrade team, Verhaegh, K., Kobussen, S., Wijkamp, T., and Kool, B.

Abstract

This paper shows first quantitative analysis of the detachment processes in the MAST Upgrade Super-X divertor (SXD). We identify an unprecedented impact of plasma-molecular interactions involving molecular ions (likely D 2 + ), resulting in strong ion sinks (Molecular Activated Recombination—MAR), leading to a reduction of ion target flux. The MAR ion sinks exceed the divertor ion sources before electron-ion recombination (EIR) starts to occur, suggesting that significant ionisation occurs outside of the divertor chamber. In the EIR region, T e ≪ 0.2 eV is observed and MAR remains significant in these deep detached phases. The total ion sink strength demonstrates the capability for particle (ion) exhaust in the Super-X Configuration. Molecular Activated Dissociation is the dominant volumetric neutral atom creation process can lead to an electron cooling of 20% of P S O L . The measured total radiative power losses in the divertor chamber are consistent with inferred hydrogenic radiative power losses. This suggests that intrinsic divertor impurity radiation, despite the carbon walls, is minor in the divertor chamber. This contrasts previous TCV results, which may be associated with enhanced plasma-neutral interactions and reduced chemical erosion in the detached, tightly baffled SXD. The above observations have also been observed in higher heat flux (narrower SOL width) type I ELMy H-mode discharges. This provides evidence that the characterisation in this paper may be general.

Published
2023

21. The X-Point radiating regime at ASDEX Upgrade and TCV

Author

EUROfusion MST1 Team, the TCV team, the ASDEX-Upgrade team, Bernert, M., Wiesen, S., Février, O., Kallenbach, A., Koenders, J.T.W., Sieglin, B., Stroth, U., Bosman, T.O.S.J., Brida, D., Cavedon, M., David, P., Dunne, M.G., Henderson, S., Kool, B., Lunt, T., McDermott, R.M., Pan, O., Perek, A., Reimerdes, H., Sheikh, U., Theiler, C., van Berkel, M., Wijkamp, T., Wischmeier, M., EUROfusion MST1 Team, the TCV team, the ASDEX-Upgrade team, Bernert, M., Wiesen, S., Février, O., Kallenbach, A., Koenders, J.T.W., Sieglin, B., Stroth, U., Bosman, T.O.S.J., Brida, D., Cavedon, M., David, P., Dunne, M.G., Henderson, S., Kool, B., Lunt, T., McDermott, R.M., Pan, O., Perek, A., Reimerdes, H., Sheikh, U., Theiler, C., van Berkel, M., Wijkamp, T., and Wischmeier, M.

Abstract

Future fusion reactors require a safe, steady-state divertor operation. With deep divertor detachment, which is typically induced by impurity seeding, the radiation concentrates in a small region at the X-point or on closed flux surfaces above the X-point. This so-called X-point radiator (XPR) moves further inside the confined region with increasing seeding and the location can be actively controlled. At AUG, the parameter space for operation with an XPR was significantly extended, using active feedback on the XPR location. The XPR is observed in nearly the whole operational space of AUG in the high-densities or high collisionality regime. ELM suppression is consistently observed in all cases where the XPR was moved to a significant height above the X-point. Direct measurements of density and temperature from the region around the XPR using the new divertor Thomson scattering system at AUG indicate that the temperature at the location of the XPR remains high (>30eV) and only the region towards the X-point cools down further. In this cold XPR core, the temperature reduces to about 1eV. An XPR is also observed in TCV by the injection of nitrogen as extrinsic impurity. This highlights that the wall material (W for AUG, C for TCV) or machine size does not play a significant role for the existence of the regime. However, the scenario appears to be less stable in TCV. First experiments show the necessity of an active control for the XPR: Depending on the wall conditions and the nitrogen wall storage, the required nitrogen seeding level to achieve an XPR changes. Both, the low temperatures measured radially outside of the radiation zone at AUG, and the lower stability of the XPR regime at TCV with the presence of carbon are consistent with the predictions of a one-dimensional model of the XPR. However, the model would predict the development of the cold XPR core, and significant radiation at the X-point might already exist before reaching this cold temperature soluti

Published
2023

22. Characterisation of detachment in the MAST-U Super-X divertor using multi-wavelength imaging of 2D atomic and molecular emission processes

Author

MAST Upgrade team, Wijkamp, T., Kool, B., Verhaegh, K., Perek, A., Classen, I.G.J., Jaspers, R.J.E., MAST Upgrade team, Wijkamp, T., Kool, B., Verhaegh, K., Perek, A., Classen, I.G.J., and Jaspers, R.J.E.

Abstract

In this work, we provide the first 2D spatially resolved description of radiative detachment in MAST-U Super-X L-mode divertor plasmas. The Super-X magnetic configuration was designed to achieve reduced heat- and particle loads at the divertor target compared to conventional exhaust solutions. We use filtered camera imaging to reconstruct 2D emissivity profiles in the poloidal plane for multiple atomic and molecular emission lines and bands. A set of deuterium fuelling scans is discussed that, together, span attached to deeply detached divertor states observed in MAST-U. Emissivity profiles facilitate separate analysis of locked-mode induced split branches of the scrape-off layer. Molecular deuterium Fulcher band emission front tracking reveals that the deuterium electron-impact ionisation front, for which it serves a proxy, detaches at different upstream electron densities in the split branches. Upon detachment of this ionisation front, Balmer emission attributed to molecular activated recombination appears near-target. We report a simultaneous radial broadening of the emission leg, consistent with previous SOLPS-ITER modelling. With increased fuelling this emission region detaches, implying electron temperatures below ∼ 1 eV. In this phase, 2D Balmer line ratio reconstruction indicates an onset of volumetric direct electron-ion recombination near-target. At the highest fuelling rates this emission region moves off-target, suggesting a drop in near-wall electron density accompanying the low temperatures.

Published
2023

23. Spectroscopic investigations of detachment on the MAST Upgrade Super-X divertor

Author

Verhaegh, K., Lipschultz, B., Harrison, J.R., Osborne, N., Williams, A.C., Ryan, P., Allcock, J., Clark, J.G., Federici, F., Kool, B., Wijkamp, T., Fil, A., Moulton, D., Myatra, O., Thornton, A., Bosman, T.O.S.J., Bowman, C., Cunningham, G., Duval, B.P., Henderson, S., Scannell, R., Verhaegh, K., Lipschultz, B., Harrison, J.R., Osborne, N., Williams, A.C., Ryan, P., Allcock, J., Clark, J.G., Federici, F., Kool, B., Wijkamp, T., Fil, A., Moulton, D., Myatra, O., Thornton, A., Bosman, T.O.S.J., Bowman, C., Cunningham, G., Duval, B.P., Henderson, S., and Scannell, R.

Abstract

We present the first analysis of the atomic and molecular processes at play during detachment in the MAST-U Super-X divertor using divertor spectroscopy data. Our analysis indicates detachment in the MAST-U Super-X divertor can be separated into four sequential phases: first, the ionisation region detaches from the target at detachment onset leaving a region of increased molecular densities downstream. The plasma interacts with these molecules, resulting in molecular ions ( D 2 + and/or D 2 − → D + D − ) that further react with the plasma leading to molecular activated recombination and dissociation (MAR and MAD), which results in excited atoms and significant Balmer line emission. Second, the MAR region detaches from the target leaving a sub-eV temperature region downstream. Third, an onset of strong emission from electron-ion recombination (EIR) ensues. Finally, the electron density decays near the target, resulting in the bulk of the electron density moving upstream. The analysis in this paper indicates that plasma-molecule interactions have a larger impact than previously reported and play a critical role in the intensity and interpretation of hydrogen atomic line emission characteristics on MAST-U. Furthermore, we find that the Fulcher band emission profile in the divertor can be used as a proxy for the ionisation region and may also be employed as a plasma temperature diagnostic for improving the separation of hydrogenic emission arising from electron-impact excitation and that from plasma-molecular interactions. We provide evidences for the presence of low electron temperatures (≪0.5 eV) during detachment phases III-IV based on quantitative spectroscopy analysis, a Boltzmann relation of the high-n Balmer line transitions together with an analysis of the brightness of high-n Balmer lines.

Published
2023

24. Overview of the TCV tokamak experimental programme

Author

Reimerdes, H., Agostini, M., Alessi, E., Alberti, S., Andrebe, Y., Arnichand, H., Balbin, J., Bagnato, F., Baquero-Ruiz, M., Bernert, M., Bin, W., Blanchard, P., Blanken, T.C., Boedo, J. A., Brida, D., Brunner, S., Bogar, C., Bogar, O., Bolzonella, T., Bombarda, F., Bouquey, F., Bowman, C., Brunetti, D., Buermans, J., Bufferand, H., Calacci, L., Camenen, Y., Carli, S., Carnevale, D., Carpanese, F., Causa, F., Cavalier, J., Cavedon, M., Cazabonne, J. A., Cerovsky, J., Chandra, R., Chandrarajan Jayalekshmi, A., Chellaï, O., Chmielewski, P., Choi, D., Eriksson, F., Sun, G., Ciralo, G., Classen, I. G. J., Coda, S., Colandrea, C., Dal Molin, A., David, P., de Baar, M. R., Decker, J., Dekeyser, W., de Oliveira, H., Douai, D., Dreval, M., Dunne, M. G., Duval, B. P., Elmore, S., Embreus, O., Faitsch, M., Falchetto, G., Farnik, M., Fasoli, A., Fedorczak, N., Felici, F., Février, O., Ficker, O., Fil, A., Fontana, M., Fransson, E., Frassinetti, L., Furno, I., Gahle, D. S., Galassi, D., Galazka, K., Galperti, C., Garavaglia, S., Garcia-Munoz, M., Geiger, B., Giacomin, M., Giruzzi, G., Gobbin, M., Golfinopoulos, T., Goodman, T., Gorno, S., Granucci, G., Graves, J. P., Griener, M., Gruca, M., Gyergyek, T., Haelterman, R., Hakola, A., Han, W., Happel, T., Harrer, G., Harrison, J. R., Henderson, S., Hogeweij, G. M. D., Hogge, J. -P., Hoppe, M., Horacek, J., Huang, Z., Iantchenko, A., Innocente, P., Insulander Björk, K., Ionita-Schrittweiser, C., Isliker, H., Jardin, A., Jaspers, R. J. E., Karimov, R., Karpushov, A. N., Kazakov, Y., Komm, M., Kong, M., Kovacic, J., Krutkin, O., Kudlacek, O., Kumar, U., Kwiatkowski, R., Labit, B., Laguardia, L., Lammers, J. T., Laribi, E., Laszynska, E., Lazaros, A., Linder, O., Linehan, B., Lipschultz, B., Llobet, X., Loizu, J., Lunt, T., Macusova, E., Marandet, M., Maraschek, M., Marceca, G., Marchetto, C., Machioni, S., Marmar, E. S., Martin, Y., Martinelli, L., Matos, F., Maurizio, R., Mayoral, M.-L., Mazon, D., Menkovski, V., Merle, A., Merlo, G., Meyer, H., Mikszuta-Michalik, K., Molina Cabrera, P. A., Morales, J., Moret, J.-M, Moro, A., Moulton, D., Muhammed, H., Myatra, O., Mykytchuk, D., Napoli, F., Nem, R. D., Nielsen, Anders Henry, Nocente, M., Nowak, S., Offeddu, N., Olsen, J., Orsitto, F. P., Pan, O., Papp, G., Pau, A., Perek, A., Pesamosca, F., Peysson, Y., Pigatto, L., Piron, C., Poradzinski, M., Porte, L., Pütterich, T., Rabinski, M., Raj, H., Rasmussen, Jens Juul, Rattá, G. A., Ravensbergen, T., Ricci, D., Ricci, P., Rispoli, N., Riva, F., Rivero-Rodriguez, J. F., Salewski, M., Sauter, O., Schmidt, B. S., Schrittweiser, R., Sharapov, S., Sheikh, U. A., Sieglin, B., Silva, M., Smolders, A., Snicker, A., Sozzi, C., Spolaore, M., Stagni, A., Stipani, L., Tala, T., Tamain, P., Tanaka, K., Tema Biwole, A., Terranova, D., Terry, J. L., Testa, D., Theiler, C., Thornton, A., Thrysøe, Alexander Simon, Torreblanca, H., Tsui, C. K., Vaccaro, D., Vallar, M., van Berkel, M., Van Eester, D., van Kampen, R. J. R., Van Mulders, S., Verhaegh, K., Verhaeghe, T., Vianello, N., Villone, F., Viezzer, E., Vincent, B., Voitsekhovitch, I., Vu, N. M. T., Walkden, N., Wauters, T., Weisen, H., Wendler, N., Wensing, M., Widmer, F., Weisen, S., Wischmeier, M., Wijkamp, T. A., Wünderlich, D., Wüthrich, C., Yanovskiy, V., Zebrowski, J., Reimerdes, H., Agostini, M., Alessi, E., Alberti, S., Andrebe, Y., Arnichand, H., Balbin, J., Bagnato, F., Baquero-Ruiz, M., Bernert, M., Bin, W., Blanchard, P., Blanken, T.C., Boedo, J. A., Brida, D., Brunner, S., Bogar, C., Bogar, O., Bolzonella, T., Bombarda, F., Bouquey, F., Bowman, C., Brunetti, D., Buermans, J., Bufferand, H., Calacci, L., Camenen, Y., Carli, S., Carnevale, D., Carpanese, F., Causa, F., Cavalier, J., Cavedon, M., Cazabonne, J. A., Cerovsky, J., Chandra, R., Chandrarajan Jayalekshmi, A., Chellaï, O., Chmielewski, P., Choi, D., Eriksson, F., Sun, G., Ciralo, G., Classen, I. G. J., Coda, S., Colandrea, C., Dal Molin, A., David, P., de Baar, M. R., Decker, J., Dekeyser, W., de Oliveira, H., Douai, D., Dreval, M., Dunne, M. G., Duval, B. P., Elmore, S., Embreus, O., Faitsch, M., Falchetto, G., Farnik, M., Fasoli, A., Fedorczak, N., Felici, F., Février, O., Ficker, O., Fil, A., Fontana, M., Fransson, E., Frassinetti, L., Furno, I., Gahle, D. S., Galassi, D., Galazka, K., Galperti, C., Garavaglia, S., Garcia-Munoz, M., Geiger, B., Giacomin, M., Giruzzi, G., Gobbin, M., Golfinopoulos, T., Goodman, T., Gorno, S., Granucci, G., Graves, J. P., Griener, M., Gruca, M., Gyergyek, T., Haelterman, R., Hakola, A., Han, W., Happel, T., Harrer, G., Harrison, J. R., Henderson, S., Hogeweij, G. M. D., Hogge, J. -P., Hoppe, M., Horacek, J., Huang, Z., Iantchenko, A., Innocente, P., Insulander Björk, K., Ionita-Schrittweiser, C., Isliker, H., Jardin, A., Jaspers, R. J. E., Karimov, R., Karpushov, A. N., Kazakov, Y., Komm, M., Kong, M., Kovacic, J., Krutkin, O., Kudlacek, O., Kumar, U., Kwiatkowski, R., Labit, B., Laguardia, L., Lammers, J. T., Laribi, E., Laszynska, E., Lazaros, A., Linder, O., Linehan, B., Lipschultz, B., Llobet, X., Loizu, J., Lunt, T., Macusova, E., Marandet, M., Maraschek, M., Marceca, G., Marchetto, C., Machioni, S., Marmar, E. S., Martin, Y., Martinelli, L., Matos, F., Maurizio, R., Mayoral, M.-L., Mazon, D., Menkovski, V., Merle, A., Merlo, G., Meyer, H., Mikszuta-Michalik, K., Molina Cabrera, P. A., Morales, J., Moret, J.-M, Moro, A., Moulton, D., Muhammed, H., Myatra, O., Mykytchuk, D., Napoli, F., Nem, R. D., Nielsen, Anders Henry, Nocente, M., Nowak, S., Offeddu, N., Olsen, J., Orsitto, F. P., Pan, O., Papp, G., Pau, A., Perek, A., Pesamosca, F., Peysson, Y., Pigatto, L., Piron, C., Poradzinski, M., Porte, L., Pütterich, T., Rabinski, M., Raj, H., Rasmussen, Jens Juul, Rattá, G. A., Ravensbergen, T., Ricci, D., Ricci, P., Rispoli, N., Riva, F., Rivero-Rodriguez, J. F., Salewski, M., Sauter, O., Schmidt, B. S., Schrittweiser, R., Sharapov, S., Sheikh, U. A., Sieglin, B., Silva, M., Smolders, A., Snicker, A., Sozzi, C., Spolaore, M., Stagni, A., Stipani, L., Tala, T., Tamain, P., Tanaka, K., Tema Biwole, A., Terranova, D., Terry, J. L., Testa, D., Theiler, C., Thornton, A., Thrysøe, Alexander Simon, Torreblanca, H., Tsui, C. K., Vaccaro, D., Vallar, M., van Berkel, M., Van Eester, D., van Kampen, R. J. R., Van Mulders, S., Verhaegh, K., Verhaeghe, T., Vianello, N., Villone, F., Viezzer, E., Vincent, B., Voitsekhovitch, I., Vu, N. M. T., Walkden, N., Wauters, T., Weisen, H., Wendler, N., Wensing, M., Widmer, F., Weisen, S., Wischmeier, M., Wijkamp, T. A., Wünderlich, D., Wüthrich, C., Yanovskiy, V., and Zebrowski, J.

Abstract

The tokamak à configuration variable (TCV) continues to leverage its unique shaping capabilities, flexible heating systems and modern control system to address critical issues in preparation for ITER and a fusion power plant. For the 2019–20 campaign its configurational flexibility has been enhanced with the installation of removable divertor gas baffles, its diagnostic capabilities with an extensive set of upgrades and its heating systems with new dual frequency gyrotrons. The gas baffles reduce coupling between the divertor and the main chamber and allow for detailed investigations on the role of fuelling in general and, together with upgraded boundary diagnostics, test divertor and edge models in particular. The increased heating capabilities broaden the operational regime to include Te/Ti ∼ 1 and have stimulated refocussing studies from L-mode to H-mode across a range of research topics. ITER baseline parameters were reached in type-I ELMy H-modes and alternative regimes with ‘small’ (or no) ELMs explored. Most prominently, negative triangularity was investigated in detail and confirmed as an attractive scenario with H-mode level core confinement but an L-mode edge. Emphasis was also placed on control, where an increased number of observers, actuators and control solutions became available and are now integrated into a generic control framework as will be needed in future devices. The quantity and quality of results of the 2019–20 TCV campaign are a testament to its successful integration within the European research effort alongside a vibrant domestic programme and international collaborations.

Published
2022

25. Overview of the TCV tokamak experimental programme

Author

Reimerdes, H. Agostini, M. Alessi, E. Alberti, S. and Andrebe, Y. Arnichand, H. Balbin, J. Bagnato, F. and Baquero-Ruiz, M. Bernert, M. Bin, W. Blanchard, P. and Blanken, T. C. Boedo, J. A. Brida, D. Brunner, S. Bogar, C. Bogar, O. Bolzonella, T. Bombarda, F. Bouquey, F. and Bowman, C. Brunetti, D. Buermans, J. Bufferand, H. and Calacci, L. Camenen, Y. Carli, S. Carnevale, D. and Carpanese, F. Causa, F. Cavalier, J. Cavedon, M. and Cazabonne, J. A. Cerovsky, J. Chandra, R. Jayalekshmi, A. Chandrarajan Chellai, O. Chmielewski, P. Choi, D. and Ciraolo, G. Classen, I. G. J. Coda, S. Colandrea, C. Dal Molin, A. David, P. de Baar, M. R. Decker, J. Dekeyser, W. de Oliveira, H. Douai, D. Dreval, M. Dunne, M. G. and Duval, B. P. Elmore, S. Embreus, O. Eriksson, F. and Faitsch, M. Falchetto, G. Farnik, M. Fasoli, A. and Fedorczak, N. Felici, F. Fevrier, O. Ficker, O. Fil, A. and Fontana, M. Fransson, E. Frassinetti, L. Furno, I and Gahle, D. S. Galassi, D. Galazka, K. Galperti, C. and Garavaglia, S. Garcia-Munoz, M. Geiger, B. Giacomin, M. and Giruzzi, G. Gobbin, M. Golfinopoulos, T. Goodman, T. and Gorno, S. Granucci, G. Graves, J. P. Griener, M. Gruca, M. Gyergyek, T. Haelterman, R. Hakola, A. Han, W. and Happel, T. Harrer, G. Harrison, J. R. Henderson, S. and Hogeweij, G. M. D. Hogge, J-P Hoppe, M. Horacek, J. and Huang, Z. Iantchenko, A. Innocente, P. Bjork, K. Insulander and Ionita-Schrittweiser, C. Isliker, H. Jardin, A. Jaspers, R. J. E. Karimov, R. Karpushov, A. N. Kazakov, Y. Komm, M. Kong, M. Kovacic, J. Krutkin, O. Kudlacek, O. and Kumar, U. Kwiatkowski, R. Labit, B. Laguardia, L. and Lammers, J. T. Laribi, E. Laszynska, E. Lazaros, A. and Linder, O. Linehan, B. Lipschultz, B. Llobet, X. Loizu, J. Lunt, T. Macusova, E. Marandet, Y. Maraschek, M. and Marceca, G. Marchetto, C. Marchioni, S. Marmar, E. S. and Martin, Y. Martinelli, L. Matos, F. Maurizio, R. and Mayoral, M-L Mazon, D. Menkovski, V Merle, A. Merlo, G. and Meyer, H. Mikszuta-Michalik, K. Cabrera, P. A. Molina and Morales, J. Moret, J-M Moro, A. Moulton, D. Muhammed, H. and Myatra, O. Mykytchuk, D. Napoli, F. Nem, R. D. and Nielsen, A. H. Nocente, M. Nowak, S. Offeddu, N. Olsen, J. Orsitto, F. P. Pan, O. Papp, G. Pau, A. Perek, A. and Pesamosca, F. Peysson, Y. Pigatto, L. Piron, C. and Poradzinski, M. Porte, L. Putterich, T. Rabinski, M. and Raj, H. Rasmussen, J. J. Ratta, G. A. Ravensbergen, T. and Ricci, D. Ricci, P. Rispoli, N. Riva, F. and Rivero-Rodriguez, J. F. Salewski, M. Sauter, O. Schmidt, B. S. Schrittweiser, R. Sharapov, S. Sheikh, U. A. Sieglin, B. Silva, M. Smolders, A. Snicker, A. Sozzi, C. and Spolaore, M. Stagni, A. Stipani, L. Sun, G. Tala, T. and Tamain, P. Tanaka, K. Biwole, A. Tema Terranova, D. and Terry, J. L. Testa, D. Theiler, C. Thornton, A. Thrysoe, A. Torreblanca, H. Tsui, C. K. Vaccaro, D. Vallar, M. and van Berkel, M. Van Eester, D. van Kampen, R. J. R. Van Mulders, S. Verhaegh, K. Verhaeghe, T. Vianello, N. and Villone, F. Viezzer, E. Vincent, B. Voitsekhovitch, I and Vu, N. M. T. Walkden, N. Wauters, T. Weisen, H. Wendler, N. Wensing, M. Widmer, F. Wiesen, S. Wischmeier, M. and Wijkamp, T. A. Wunderlich, D. Wuthrich, C. Yanovskiy, V and Zebrowski, J. EUROfusion MST1 Team

Abstract

The tokamak a configuration variable (TCV) continues to leverage its unique shaping capabilities, flexible heating systems and modern control system to address critical issues in preparation for ITER and a fusion power plant. For the 2019-20 campaign its configurational flexibility has been enhanced with the installation of removable divertor gas baffles, its diagnostic capabilities with an extensive set of upgrades and its heating systems with new dual frequency gyrotrons. The gas baffles reduce coupling between the divertor and the main chamber and allow for detailed investigations on the role of fuelling in general and, together with upgraded boundary diagnostics, test divertor and edge models in particular. The increased heating capabilities broaden the operational regime to include T (e)/T (i) similar to 1 and have stimulated refocussing studies from L-mode to H-mode across a range of research topics. ITER baseline parameters were reached in type-I ELMy H-modes and alternative regimes with `small' (or no) ELMs explored. Most prominently, negative triangularity was investigated in detail and confirmed as an attractive scenario with H-mode level core confinement but an L-mode edge. Emphasis was also placed on control, where an increased number of observers, actuators and control solutions became available and are now integrated into a generic control framework as will be needed in future devices. The quantity and quality of results of the 2019-20 TCV campaign are a testament to its successful integration within the European research effort alongside a vibrant domestic programme and international collaborations.

Published
2022

26. Validation of 2D Te and ne measurements made with Helium imaging spectroscopy in the volume of the TCV divertor

Author

Linehan, B., Perek, A., Duval, B.P., Bagnato, F., Blanchard, P., Colandrea, C., de Oliveira, H., Février, O., Flom, E., Wijkamp, T., Gorno, S., Goto, M., Marmar, S., Martinelli, L., Mathews, A., Munoz-Burgos, J.M., Mykytchuk, D., Offeddu, N., Oliveira, D.S., Reimerdes, H., Reiter, D., Schmitz, O., Terry, J.L., Theiler, C., Tsui, C.K., Vincent, B., Wuthrich, C., Zholobenko, W., team, TCV, and TCV Team

Subjects
Nuclear and High Energy Physics, Condensed Matter Physics
Abstract

Multi-spectral imaging of helium atomic emission (HeMSI) has been used to create 2D poloidal maps of T e and n e in TCV’s divertor. To achieve these measurements, TCV’s MANTIS multispectral cameras (Perek et al 2019 Rev. Sci. Instrum. 90 123514) simultaneously imaged four He I lines (two singlet and two triplet) and a He II line (468 nm) from passively present He and He+. The images, which were absolutely calibrated and covered the whole divertor region, were inverted through the assumption of toroidal symmetry to create emissivity profiles and, consequently, line-ratio profiles. A collisional-radiative model (CRM) was applied to the line-ratio profiles to produce 2D poloidal maps of T e and n e . The collisional-radiative modeling was accomplished with the Goto helium CRM code (Zholobenko et al 2018 Nucl. Fusion 58 126006, Zholobenko et al 2018 Technical Report, Goto 2003 J. Quant. Spectrosc. Radiat. Transfer 76 331–44) which accounts for electron-impact excitation (EIE) and deexcitation, and electron–ion recombination (EIR) with He + . The HeMSI T e and n e measurements were compared with co-local Thomson scattering measurements. The two sets of measurements exhibited good agreement for ionizing plasmas: ( 5 eV ⩽ T e ⩽ 60 eV , and 2 × 10 18 m − 3 ⩽ n e ⩽ 3 × 10 19 m − 3 ) in the case of majority helium plasmas, and ( 10 eV ⩽ T e ⩽ 40 eV , 2 × 10 18 m − 3 ⩽ n e ⩽ 3 × 10 19 m − 3 ) in the case of majority deuterium plasmas. However, there were instances where HeMSI measurements diverged from Thomson scattering. When T e ⩽ 10 eV in majority deuterium plasmas, HeMSI deduced inaccurately high values of T e . This disagreement cannot be rectified within the CRM’s EIE and EIR framework. Second, on sporadic occasions within the private flux region, HeMSI produced erroneously high measurements of n e . Multi-spectral imaging of Helium emission has been demonstrated to produce accurate 2D poloidal maps of T e and n e within the divertor of a tokamak for plasma conditions relevant to contemporary divertor studies.

Published
2023

27. DIII-D research towards establishing the scientific basis for future fusion reactors

Author

Abadie, L, Abrams, T, Ahn, J, Akiyama, T, Aleynikov, P, Allcock, J, Allen, E, Allen, S, Anderson, J, Ashourvan, A, Austin, M, Bak, J, Barada, K, Barbour, N, Bardoczi, L, Barr, J, Barton, J, Bass, E, Battaglia, D, Baylor, L, Beckers, J, Belli, E, Berkery, J, Bertelli, N, Bialek, J, Boedo, J, Boivin, R, Bonoli, P, Bortolon, A, Boyer, M, Brambila, R, Bray, B, Brennan, D, Briesemeister, A, Bringuier, S, Brookman, M, Brower, D, Brown, B, Brown, W, Buchenauer, D, Burke, M, Burrell, K, Butt, J, Buttery, R, Bykov, I, Candy, J, Canik, J, Cao, N, Carbajal Gomez, L, Carlson, L, Carlstrom, T, Carter, T, Cary, W, Casali, L, Cengher, M, Chan, V, Chen, B, Chen, J, Chen, M, Chen, R, Chen, X, Choi, W, Chrobak, C, Chrystal, C, Churchill, R, Cianciosa, M, Clauser, C, Clement, M, Coburn, J, Collins, C, Cooper, A, Covele, B, Crippen, J, Crocker, N, Crowley, B, Dal Molin, A, Davis, E, Degrassie, J, del-Castillo-Negrete, C, Delgado-Aparicio, L, Diallo, A, Diem, S, Ding, R, Ding, S, Ding, W, Doane, J, Donovan, D, Drake, J, Du, D, Du, H, Du, X, Duarte, V, Duran, J, Eidietis, N, Elder, D, Eldon, D, Elwasif, W, Ely, T, Eng, K, Engelhorn, K, Ennis, D, Erickson, K, Ernst, D, Evans, T, Fenstermacher, M, Ferraro, N, Ferron, J, Finkenthal, D, Fisher, P, Fishler, B, Flanagan, S, Fooks, J, Frassinetti, L, Frerichs, H, Fu, Y, Fulop, T, Gao, Q, Garcia, F, Garofalo, A, Gattuso, A, Giacomelli, L, Giraldez, E, Giroud, C, Glass, F, Gohil, P, Gong, X, Gorelov, Y, Granetz, R, Green, D, Greenfield, C, Grierson, B, Groebner, R, Grosnickle, W, Groth, M, Grunloh, H, Guo, H, Guo, W, Guterl, J, Hager, R, Hahn, S, Halpern, F, Han, H, Hansink, M, Hanson, J, Harris, J, Haskey, S, Hatch, D, Heidbrink, W, Herfindal, J, Hill, D, Hill, M, Hinson, E, Holcomb, C, Holland, C, Holland, L, Hollmann, E, Holm, A, Hong, R, Hoppe, M, Houshmandyar, S, Howard, J, Howard, N, Hu, Q, Hu, W, Huang, H, Huang, J, Huang, Y, Hughes, G, Hughes, J, Humphreys, D, Hyatt, A, Ida, K, Igochine, V, In, Y, Inoue, S, Isayama, A, Isler, R, Izzo, V, Jackson, M, Jarvinen, A, Jeon, Y, Ji, H, Jian, X, Jimenez, R, Johnson, C, Joseph, I, Kaczala, D, Kaplan, D, Kates-Harbeck, J, Kellman, A, Kellman, D, Kessel, C, Khumthong, K, Kim, C, Kim, H, Kim, J, Kim, K, Kim, S, Kimura, W, King, J, Kirk, A, Kleijwegt, K, Knolker, M, Kohn, A, Kolemen, E, Kostuk, M, Kramer, G, Kress, P, Kriete, D, La Haye, R, Laggner, F, Lan, H, Lanctot, M, Lantsov, R, Lao, L, Lasnier, C, Lau, C, Law, K, Lawrence, D, Le, J, Lee, R, Lehnen, M, Leon, R, Leonard, A, Lesher, M, Leuer, J, Li, G, Li, K, Liao, K, Lin, Z, Liu, C, Liu, F, Liu, Y, Liu, Z, Loch, S, Logan, N, Lohr, J, Lore, J, Luce, T, Luhmann, N, Lunsford, R, Luo, C, Luo, Z, Lupin-Jimenez, L, Lvovskiy, A, Lyons, B, Ma, X, Maingi, R, Makowski, M, Mantica, P, Manuel, M, Margo, M, Marinoni, A, Marmar, E, Martin, W, Masline, R, Matsunaga, G, Mauzey, D, Mauzey, P, Mcclenaghan, J, Mckee, G, Mclean, A, Mclean, H, Meier, E, Meitner, S, Menard, J, Meneghini, O, Merlo, G, Meyer, W, Miller, D, Miller, W, Moeller, C, Montes, K, Morales, M, Mordijck, S, Moser, A, Moyer, R, Muller, S, Munaretto, S, Murakami, M, Murphy, C, Muscatello, C, Myers, C, Nagy, A, Navratil, G, Nazikian, R, Neff, A, Neiser, T, Nelson, A, Nguyen, P, Nguyen, R, Nichols, J, Nocente, M, Nygren, R, O'Neill, R, Odstrcil, T, Ohdachi, S, Okabayashi, M, Olofsson, E, Ono, M, Orlov, D, Osborne, T, Pablant, N, Pace, D, Paguio, R, Pajares Martinez, A, Pan, C, Pankin, A, Park, J, Park, Y, Parker, C, Parker, S, Parks, P, Pawley, C, Paz-Soldan, C, Peebles, W, Penaflor, B, Petrie, T, Petty, C, Peysson, Y, Pigarov, A, Piglowski, D, Pinsker, R, Piovesan, P, Piper, N, Pitts, R, Pizzo, J, Podesta, M, Poli, F, Ponce, D, Porkolab, M, Porter, G, Prater, R, Qian, J, Ra, O, Rafiq, T, Raman, R, Rand, C, Randall, G, Rauch, J, Rea, C, Reinke, M, Ren, J, Ren, Q, Ren, Y, Rhodes, T, Rice, J, Rognlien, T, Rost, J, Rowan, W, Rudakov, D, Salmi, A, Sammuli, B, Samuell, C, Sandorfi, A, Sang, C, Sauter, O, Schissel, D, Schmitz, L, Schmitz, O, Schuster, E, Scoville, J, Seltzman, A, Sfiligoi, I, Shafer, M, Shen, H, Shi, T, Shiraki, D, Si, H, Smith, D, Smith, S, Snipes, J, Snyder, P, Solano, E, Solomon, W, Sontag, A, Soukhanovskii, V, Spong, D, Stacey, W, Staebler, G, Stagner, L, Stahl, B, Stangeby, P, Stoltzfus-Dueck, T, Stotler, D, Strait, E, Su, D, Sugiyama, L, Sulyman, A, Sun, Y, Sung, C, Suttrop, W, Suzuki, Y, Svyatkovskiy, A, Sweeney, R, Taimourzadeh, S, Takechi, M, Tala, T, Tan, H, Tang, S, Tang, X, Taussig, D, Taylor, G, Taylor, N, Taylor, T, Teklu, A, Thomas, D, Thomas, M, Thome, K, Thorman, A, Tinguely, R, Tobias, B, Tooker, J, Torreblanca, H, Torrezan De Sousa, A, Trevisan, G, Truong, D, Turco, F, Turnbull, A, Unterberg, E, Vaezi, P, Vail, P, Van Zeeland, M, Velasco Enriquez, M, Venkatesh, M, Victor, B, Volpe, F, Wade, M, Walker, M, Wall, J, Wallace, G, Waltz, R, Wang, G, Wang, H, Wang, Y, Wang, Z, Wang, F, Ward, S, Watkins, J, Watkins, M, Wehner, W, Weiland, M, Weisberg, D, Welander, A, White, A, White, R, Whyte, D, Wijkamp, T, Wilcox, R, Wilks, T, Wilson, H, Wingen, A, Wolfe, E, Wu, M, Wu, W, Wukitch, S, Xia, T, Xiang, N, Xiao, B, Xie, R, Xu, G, Xu, H, Xu, X, Yan, Z, Yang, Q, Yang, X, Yoshida, M, Yu, G, Yu, J, Yu, M, Zamperini, S, Zeng, L, Zhao, B, Zhao, D, Zhao, H, Zhao, Y, Zhu, Y, Zywicki, B, L. Abadie, T. W. Abrams, J. Ahn, T. Akiyama, P. Aleynikov, J. Allcock, E. O. Allen, S. Allen, J. P. Anderson, A. Ashourvan, M. E. Austin, J. Bak, K. K. Barada, N. Barbour, L. Bardoczi, J. Barr, J. L. Barton, E. M. Bass, D. Battaglia, L. R. Baylor, J. Beckers, E. A. Belli, J. W. Berkery, N. Bertelli, J. M. Bialek, J. A. Boedo, R. L. Boivin, P. T. Bonoli, A. Bortolon, M. D. Boyer, R. E. Brambila, B. Bray, D. P. Brennan, A. R. Briesemeister, S. A. Bringuier, M. W. Brookman, D. L. Brower, B. R. Brown, W. D. Brown, D. Buchenauer, M. G. Burke, K. H. Burrell, J. Butt, R. J. Buttery, I. Bykov, J. M. Candy, J. M. Canik, N. M. Cao, L. Carbajal Gomez, L. C. Carlson, T. N. Carlstrom, T. A. Carter, W. Cary, L. Casali, M. Cengher, V. S. Chan, B. Chen, J. Chen, M. Chen, R. Chen, Xi Chen, W. Choi, C. Chrobak, C. Chrystal, R. M. Churchill, M. Cianciosa, C. F. Clauser, M. Clement, J. Coburn, C. S. Collins, A. W. Cooper, B. M. Covele, J. W. Crippen, N. A. Crocker, B. J. Crowley, A. Dal Molin, E. M. Davis, J. S. deGrassie, C. A. del-Castillo-Negrete, L. F. Delgado-Aparicio, A. Diallo, S. J. Diem, R. Ding, S. Ding, W. Ding, J. L. Doane, D. C. Donovan, J. Drake, D. Du, H. Du, X. Du, V. Duarte, J. D. Duran, N. W. Eidietis, D. Elder, D. Eldon, W. Elwasif, T. E. Ely, K. M. Eng, K. Engelhorn, D. Ennis, K. Erickson, D. R. Ernst, T. E. Evans, M. E. Fenstermacher, N. M. Ferraro, J. R. Ferron, D. F. Finkenthal, P. A. Fisher, B. Fishler, S. M. Flanagan, J. A. Fooks, L. Frassinetti, H. G. Frerichs, Y. Fu, T. Fulop, Q. Gao, F. Garcia, A. M. Garofalo, A. Gattuso, L. Giacomelli, E. M. Giraldez, C. Giroud, F. Glass, P. Gohil, X. Gong, Y. A. Gorelov, R. S. Granetz, D. L. Green, C. M. Greenfield, B. A. Grierson, R. J. Groebner, W. H. Grosnickle, M. Groth, H. J. Grunloh, H. Y. Guo, W. Guo, J. Guterl, R. C. Hager, S. Hahn, F. D. Halpern, H. Han, M. J. Hansink, J. M. Hanson, J. Harris, S. R. Haskey, D. R. Hatch, W. W. Heidbrink, J. Herfindal, D. N. Hill, M. D. Hill, E. T. Hinson, C. T. Holcomb, C. G. Holland, L. D. Holland, E. M. Hollmann, A. M. Holm, R. Hong, M. Hoppe, S. Houshmandyar, J. Howard, N. T. Howard, Q. Hu, W. Hu, H. Huang, J. Huang, Y. Huang, G. A. Hughes, J. Hughes, D. A. Humphreys, A. W. Hyatt, K. Ida, V. Igochine, Y. In, S. Inoue, A. Isayama, R. C. Isler, V. A. Izzo, M. R. Jackson, A. E. Jarvinen, Y. Jeon, H. Ji, X. Jian, R. Jimenez, C. A. Johnson, I. Joseph, D. N. Kaczala, D. H. Kaplan, J. Kates-Harbeck, A. G. Kellman, D. H. Kellman, C. E. Kessel, K. Khumthong, C. C. Kim, H. Kim, J. Kim, K. Kim, S. H. Kim, W. Kimura, J. R. King, A. Kirk, K. Kleijwegt, M. Knolker, A. Kohn, E. Kolemen, M. Kostuk, G. J. Kramer, P. Kress, D. M. Kriete, R. J. La Haye, F. M. Laggner, H. Lan, M. J. Lanctot, R. Lantsov, L. L. Lao, C. J. Lasnier, C. Lau, K. Law, D. Lawrence, J. Le, R. L. Lee, M. Lehnen, R. Leon, A. W. Leonard, M. Lesher, J. A. Leuer, G. Li, K. Li, K. T. Liao, Z. Lin, C. Liu, F. Liu, Y. Liu, Z. Liu, S. Loch, N. C. Logan, J. M. Lohr, J. Lore, T. C. Luce, N. C. Luhmann, R. Lunsford, C. Luo, Z. Luo, L. Lupin-Jimenez, A. Lvovskiy, B. C. Lyons, X. Ma, R. Maingi, M. A. Makowski, P. Mantica, M. Manuel, M. W. Margo, A. Marinoni, E. Marmar, W. C. Martin, R. L. Masline, G. K. Matsunaga, D. M. Mauzey, P. S. Mauzey, J. T. Mcclenaghan, G. R. Mckee, A. G. Mclean, H. S. Mclean, E. Meier, S. J. Meitner, J. E. Menard, O. Meneghini, G. Merlo, W. H. Meyer, D. C. Miller, W. J. Miller, C. P. Moeller, K. J. Montes, M. A. Morales, S. Mordijck, A. Moser, R. A. Moyer, S. A. Muller, S. Munaretto, M. Murakami, C. J. Murphy, C. M. Muscatello, C. E. Myers, A. Nagy, G. A. Navratil, R. M. Nazikian, A. L. Neff, T. F. Neiser, A. Nelson, P. Nguyen, R. Nguyen, J. H. Nichols, M. Nocente, R. E. Nygren, R. C. O'Neill, T. Odstrcil, S. Ohdachi, M. Okabayashi, E. Olofsson, M. Ono, D. M. Orlov, T. H. Osborne, N. A. Pablant, D. C. Pace, R. R. Paguio, A. Pajares Martinez, C. Pan, A. Pankin, J. M. Park, J. Park, Y. Park, C. T. Parker, S. E. Parker, P. B. Parks, C. J. Pawley, C. A. Paz-Soldan, W. A. Peebles, B. G. Penaflor, T. W. Petrie, C. C. Petty, Y. Peysson, A. Y. Pigarov, D. A. Piglowski, R. I. Pinsker, P. Piovesan, N. Piper, R. A. Pitts, J. D. Pizzo, M. L. Podesta, F. M. Poli, D. Ponce, M. Porkolab, G. D. Porter, R. Prater, J. Qian, O. Ra, T. Rafiq, R. Raman, C. Rand, G. C. Randall, J. M. Rauch, C. Rea, M. L. Reinke, J. Ren, Q. Ren, Y. Ren, T. L. Rhodes, J. Rice, T. D. Rognlien, J. C. Rost, W. L. Rowan, D. L. Rudakov, A. Salmi, B. S. Sammuli, C. M. Samuell, A. M. Sandorfi, C. Sang, O. J. Sauter, D. P. Schissel, L. Schmitz, O. Schmitz, E. J. Schuster, J. T. Scoville, A. Seltzman, I. Sfiligoi, M. Shafer, H. Shen, T. Shi, D. Shiraki, H. Si, D. R. Smith, S. P. Smith, J. A. Snipes, P. B. Snyder, E. R. Solano, W. M. Solomon, A. C. Sontag, V. A. Soukhanovskii, D. A. Spong, W. M. Stacey, G. M. Staebler, L. Stagner, B. Stahl, P. C. Stangeby, T. J. Stoltzfus-Dueck, D. P. Stotler, E. J. Strait, D. Su, L. E. Sugiyama, A. A. Sulyman, Y. Sun, C. Sung, W. A. Suttrop, Y. Suzuki, A. Svyatkovskiy, R. M. Sweeney, S. Taimourzadeh, M. Takechi, T. Tala, H. Tan, S. Tang, X. Tang, D. Taussig, G. Taylor, N. Z. Taylor, T. S. Taylor, A. Teklu, D. M. Thomas, M. B. Thomas, K. E. Thome, A. R. Thorman, R. A. Tinguely, B. J. Tobias, J. F. Tooker, H. Torreblanca, A. Torrezan De Sousa, G. L. Trevisan, D. Truong, F. Turco, A. D. Turnbull, E. A. Unterberg, P. Vaezi, P. J. Vail, M. A. Van Zeeland, M. Velasco Enriquez, M. C. Venkatesh, B. S. Victor, F. Volpe, M. R. Wade, M. L. Walker, J. R. Wall, G. M. Wallace, R. E. Waltz, G. Wang, H. Wang, Y. Wang, Z. Wang, F. Wang, S. H. Ward, J. G. Watkins, M. Watkins, W. P. Wehner, M. Weiland, D. B. Weisberg, A. S. Welander, A. E. White, R. B. White, D. Whyte, T. A. Wijkamp, R. Wilcox, T. Wilks, H. R. Wilson, A. Wingen, E. Wolfe, M. Wu, W. Wu, S. J. Wukitch, T. Xia, N. Xiang, B. Xiao, R. Xie, G. Xu, H. Xu, X. Xu, Z. Yan, Q. Yang, X. Yang, M. Yoshida, G. Yu, J. H. Yu, M. Yu, S. A. Zamperini, L. Zeng, B. Zhao, D. Zhao, H. Zhao, Y. Zhao, Y. Zhu, B. Zywicki, Abadie, L, Abrams, T, Ahn, J, Akiyama, T, Aleynikov, P, Allcock, J, Allen, E, Allen, S, Anderson, J, Ashourvan, A, Austin, M, Bak, J, Barada, K, Barbour, N, Bardoczi, L, Barr, J, Barton, J, Bass, E, Battaglia, D, Baylor, L, Beckers, J, Belli, E, Berkery, J, Bertelli, N, Bialek, J, Boedo, J, Boivin, R, Bonoli, P, Bortolon, A, Boyer, M, Brambila, R, Bray, B, Brennan, D, Briesemeister, A, Bringuier, S, Brookman, M, Brower, D, Brown, B, Brown, W, Buchenauer, D, Burke, M, Burrell, K, Butt, J, Buttery, R, Bykov, I, Candy, J, Canik, J, Cao, N, Carbajal Gomez, L, Carlson, L, Carlstrom, T, Carter, T, Cary, W, Casali, L, Cengher, M, Chan, V, Chen, B, Chen, J, Chen, M, Chen, R, Chen, X, Choi, W, Chrobak, C, Chrystal, C, Churchill, R, Cianciosa, M, Clauser, C, Clement, M, Coburn, J, Collins, C, Cooper, A, Covele, B, Crippen, J, Crocker, N, Crowley, B, Dal Molin, A, Davis, E, Degrassie, J, del-Castillo-Negrete, C, Delgado-Aparicio, L, Diallo, A, Diem, S, Ding, R, Ding, S, Ding, W, Doane, J, Donovan, D, Drake, J, Du, D, Du, H, Du, X, Duarte, V, Duran, J, Eidietis, N, Elder, D, Eldon, D, Elwasif, W, Ely, T, Eng, K, Engelhorn, K, Ennis, D, Erickson, K, Ernst, D, Evans, T, Fenstermacher, M, Ferraro, N, Ferron, J, Finkenthal, D, Fisher, P, Fishler, B, Flanagan, S, Fooks, J, Frassinetti, L, Frerichs, H, Fu, Y, Fulop, T, Gao, Q, Garcia, F, Garofalo, A, Gattuso, A, Giacomelli, L, Giraldez, E, Giroud, C, Glass, F, Gohil, P, Gong, X, Gorelov, Y, Granetz, R, Green, D, Greenfield, C, Grierson, B, Groebner, R, Grosnickle, W, Groth, M, Grunloh, H, Guo, H, Guo, W, Guterl, J, Hager, R, Hahn, S, Halpern, F, Han, H, Hansink, M, Hanson, J, Harris, J, Haskey, S, Hatch, D, Heidbrink, W, Herfindal, J, Hill, D, Hill, M, Hinson, E, Holcomb, C, Holland, C, Holland, L, Hollmann, E, Holm, A, Hong, R, Hoppe, M, Houshmandyar, S, Howard, J, Howard, N, Hu, Q, Hu, W, Huang, H, Huang, J, Huang, Y, Hughes, G, Hughes, J, Humphreys, D, Hyatt, A, Ida, K, Igochine, V, In, Y, Inoue, S, Isayama, A, Isler, R, Izzo, V, Jackson, M, Jarvinen, A, Jeon, Y, Ji, H, Jian, X, Jimenez, R, Johnson, C, Joseph, I, Kaczala, D, Kaplan, D, Kates-Harbeck, J, Kellman, A, Kellman, D, Kessel, C, Khumthong, K, Kim, C, Kim, H, Kim, J, Kim, K, Kim, S, Kimura, W, King, J, Kirk, A, Kleijwegt, K, Knolker, M, Kohn, A, Kolemen, E, Kostuk, M, Kramer, G, Kress, P, Kriete, D, La Haye, R, Laggner, F, Lan, H, Lanctot, M, Lantsov, R, Lao, L, Lasnier, C, Lau, C, Law, K, Lawrence, D, Le, J, Lee, R, Lehnen, M, Leon, R, Leonard, A, Lesher, M, Leuer, J, Li, G, Li, K, Liao, K, Lin, Z, Liu, C, Liu, F, Liu, Y, Liu, Z, Loch, S, Logan, N, Lohr, J, Lore, J, Luce, T, Luhmann, N, Lunsford, R, Luo, C, Luo, Z, Lupin-Jimenez, L, Lvovskiy, A, Lyons, B, Ma, X, Maingi, R, Makowski, M, Mantica, P, Manuel, M, Margo, M, Marinoni, A, Marmar, E, Martin, W, Masline, R, Matsunaga, G, Mauzey, D, Mauzey, P, Mcclenaghan, J, Mckee, G, Mclean, A, Mclean, H, Meier, E, Meitner, S, Menard, J, Meneghini, O, Merlo, G, Meyer, W, Miller, D, Miller, W, Moeller, C, Montes, K, Morales, M, Mordijck, S, Moser, A, Moyer, R, Muller, S, Munaretto, S, Murakami, M, Murphy, C, Muscatello, C, Myers, C, Nagy, A, Navratil, G, Nazikian, R, Neff, A, Neiser, T, Nelson, A, Nguyen, P, Nguyen, R, Nichols, J, Nocente, M, Nygren, R, O'Neill, R, Odstrcil, T, Ohdachi, S, Okabayashi, M, Olofsson, E, Ono, M, Orlov, D, Osborne, T, Pablant, N, Pace, D, Paguio, R, Pajares Martinez, A, Pan, C, Pankin, A, Park, J, Park, Y, Parker, C, Parker, S, Parks, P, Pawley, C, Paz-Soldan, C, Peebles, W, Penaflor, B, Petrie, T, Petty, C, Peysson, Y, Pigarov, A, Piglowski, D, Pinsker, R, Piovesan, P, Piper, N, Pitts, R, Pizzo, J, Podesta, M, Poli, F, Ponce, D, Porkolab, M, Porter, G, Prater, R, Qian, J, Ra, O, Rafiq, T, Raman, R, Rand, C, Randall, G, Rauch, J, Rea, C, Reinke, M, Ren, J, Ren, Q, Ren, Y, Rhodes, T, Rice, J, Rognlien, T, Rost, J, Rowan, W, Rudakov, D, Salmi, A, Sammuli, B, Samuell, C, Sandorfi, A, Sang, C, Sauter, O, Schissel, D, Schmitz, L, Schmitz, O, Schuster, E, Scoville, J, Seltzman, A, Sfiligoi, I, Shafer, M, Shen, H, Shi, T, Shiraki, D, Si, H, Smith, D, Smith, S, Snipes, J, Snyder, P, Solano, E, Solomon, W, Sontag, A, Soukhanovskii, V, Spong, D, Stacey, W, Staebler, G, Stagner, L, Stahl, B, Stangeby, P, Stoltzfus-Dueck, T, Stotler, D, Strait, E, Su, D, Sugiyama, L, Sulyman, A, Sun, Y, Sung, C, Suttrop, W, Suzuki, Y, Svyatkovskiy, A, Sweeney, R, Taimourzadeh, S, Takechi, M, Tala, T, Tan, H, Tang, S, Tang, X, Taussig, D, Taylor, G, Taylor, N, Taylor, T, Teklu, A, Thomas, D, Thomas, M, Thome, K, Thorman, A, Tinguely, R, Tobias, B, Tooker, J, Torreblanca, H, Torrezan De Sousa, A, Trevisan, G, Truong, D, Turco, F, Turnbull, A, Unterberg, E, Vaezi, P, Vail, P, Van Zeeland, M, Velasco Enriquez, M, Venkatesh, M, Victor, B, Volpe, F, Wade, M, Walker, M, Wall, J, Wallace, G, Waltz, R, Wang, G, Wang, H, Wang, Y, Wang, Z, Wang, F, Ward, S, Watkins, J, Watkins, M, Wehner, W, Weiland, M, Weisberg, D, Welander, A, White, A, White, R, Whyte, D, Wijkamp, T, Wilcox, R, Wilks, T, Wilson, H, Wingen, A, Wolfe, E, Wu, M, Wu, W, Wukitch, S, Xia, T, Xiang, N, Xiao, B, Xie, R, Xu, G, Xu, H, Xu, X, Yan, Z, Yang, Q, Yang, X, Yoshida, M, Yu, G, Yu, J, Yu, M, Zamperini, S, Zeng, L, Zhao, B, Zhao, D, Zhao, H, Zhao, Y, Zhu, Y, Zywicki, B, L. Abadie, T. W. Abrams, J. Ahn, T. Akiyama, P. Aleynikov, J. Allcock, E. O. Allen, S. Allen, J. P. Anderson, A. Ashourvan, M. E. Austin, J. Bak, K. K. Barada, N. Barbour, L. Bardoczi, J. Barr, J. L. Barton, E. M. Bass, D. Battaglia, L. R. Baylor, J. Beckers, E. A. Belli, J. W. Berkery, N. Bertelli, J. M. Bialek, J. A. Boedo, R. L. Boivin, P. T. Bonoli, A. Bortolon, M. D. Boyer, R. E. Brambila, B. Bray, D. P. Brennan, A. R. Briesemeister, S. A. Bringuier, M. W. Brookman, D. L. Brower, B. R. Brown, W. D. Brown, D. Buchenauer, M. G. Burke, K. H. Burrell, J. Butt, R. J. Buttery, I. Bykov, J. M. Candy, J. M. Canik, N. M. Cao, L. Carbajal Gomez, L. C. Carlson, T. N. Carlstrom, T. A. Carter, W. Cary, L. Casali, M. Cengher, V. S. Chan, B. Chen, J. Chen, M. Chen, R. Chen, Xi Chen, W. Choi, C. Chrobak, C. Chrystal, R. M. Churchill, M. Cianciosa, C. F. Clauser, M. Clement, J. Coburn, C. S. Collins, A. W. Cooper, B. M. Covele, J. W. Crippen, N. A. Crocker, B. J. Crowley, A. Dal Molin, E. M. Davis, J. S. deGrassie, C. A. del-Castillo-Negrete, L. F. Delgado-Aparicio, A. Diallo, S. J. Diem, R. Ding, S. Ding, W. Ding, J. L. Doane, D. C. Donovan, J. Drake, D. Du, H. Du, X. Du, V. Duarte, J. D. Duran, N. W. Eidietis, D. Elder, D. Eldon, W. Elwasif, T. E. Ely, K. M. Eng, K. Engelhorn, D. Ennis, K. Erickson, D. R. Ernst, T. E. Evans, M. E. Fenstermacher, N. M. Ferraro, J. R. Ferron, D. F. Finkenthal, P. A. Fisher, B. Fishler, S. M. Flanagan, J. A. Fooks, L. Frassinetti, H. G. Frerichs, Y. Fu, T. Fulop, Q. Gao, F. Garcia, A. M. Garofalo, A. Gattuso, L. Giacomelli, E. M. Giraldez, C. Giroud, F. Glass, P. Gohil, X. Gong, Y. A. Gorelov, R. S. Granetz, D. L. Green, C. M. Greenfield, B. A. Grierson, R. J. Groebner, W. H. Grosnickle, M. Groth, H. J. Grunloh, H. Y. Guo, W. Guo, J. Guterl, R. C. Hager, S. Hahn, F. D. Halpern, H. Han, M. J. Hansink, J. M. Hanson, J. Harris, S. R. Haskey, D. R. Hatch, W. W. Heidbrink, J. Herfindal, D. N. Hill, M. D. Hill, E. T. Hinson, C. T. Holcomb, C. G. Holland, L. D. Holland, E. M. Hollmann, A. M. Holm, R. Hong, M. Hoppe, S. Houshmandyar, J. Howard, N. T. Howard, Q. Hu, W. Hu, H. Huang, J. Huang, Y. Huang, G. A. Hughes, J. Hughes, D. A. Humphreys, A. W. Hyatt, K. Ida, V. Igochine, Y. In, S. Inoue, A. Isayama, R. C. Isler, V. A. Izzo, M. R. Jackson, A. E. Jarvinen, Y. Jeon, H. Ji, X. Jian, R. Jimenez, C. A. Johnson, I. Joseph, D. N. Kaczala, D. H. Kaplan, J. Kates-Harbeck, A. G. Kellman, D. H. Kellman, C. E. Kessel, K. Khumthong, C. C. Kim, H. Kim, J. Kim, K. Kim, S. H. Kim, W. Kimura, J. R. King, A. Kirk, K. Kleijwegt, M. Knolker, A. Kohn, E. Kolemen, M. Kostuk, G. J. Kramer, P. Kress, D. M. Kriete, R. J. La Haye, F. M. Laggner, H. Lan, M. J. Lanctot, R. Lantsov, L. L. Lao, C. J. Lasnier, C. Lau, K. Law, D. Lawrence, J. Le, R. L. Lee, M. Lehnen, R. Leon, A. W. Leonard, M. Lesher, J. A. Leuer, G. Li, K. Li, K. T. Liao, Z. Lin, C. Liu, F. Liu, Y. Liu, Z. Liu, S. Loch, N. C. Logan, J. M. Lohr, J. Lore, T. C. Luce, N. C. Luhmann, R. Lunsford, C. Luo, Z. Luo, L. Lupin-Jimenez, A. Lvovskiy, B. C. Lyons, X. Ma, R. Maingi, M. A. Makowski, P. Mantica, M. Manuel, M. W. Margo, A. Marinoni, E. Marmar, W. C. Martin, R. L. Masline, G. K. Matsunaga, D. M. Mauzey, P. S. Mauzey, J. T. Mcclenaghan, G. R. Mckee, A. G. Mclean, H. S. Mclean, E. Meier, S. J. Meitner, J. E. Menard, O. Meneghini, G. Merlo, W. H. Meyer, D. C. Miller, W. J. Miller, C. P. Moeller, K. J. Montes, M. A. Morales, S. Mordijck, A. Moser, R. A. Moyer, S. A. Muller, S. Munaretto, M. Murakami, C. J. Murphy, C. M. Muscatello, C. E. Myers, A. Nagy, G. A. Navratil, R. M. Nazikian, A. L. Neff, T. F. Neiser, A. Nelson, P. Nguyen, R. Nguyen, J. H. Nichols, M. Nocente, R. E. Nygren, R. C. O'Neill, T. Odstrcil, S. Ohdachi, M. Okabayashi, E. Olofsson, M. Ono, D. M. Orlov, T. H. Osborne, N. A. Pablant, D. C. Pace, R. R. Paguio, A. Pajares Martinez, C. Pan, A. Pankin, J. M. Park, J. Park, Y. Park, C. T. Parker, S. E. Parker, P. B. Parks, C. J. Pawley, C. A. Paz-Soldan, W. A. Peebles, B. G. Penaflor, T. W. Petrie, C. C. Petty, Y. Peysson, A. Y. Pigarov, D. A. Piglowski, R. I. Pinsker, P. Piovesan, N. Piper, R. A. Pitts, J. D. Pizzo, M. L. Podesta, F. M. Poli, D. Ponce, M. Porkolab, G. D. Porter, R. Prater, J. Qian, O. Ra, T. Rafiq, R. Raman, C. Rand, G. C. Randall, J. M. Rauch, C. Rea, M. L. Reinke, J. Ren, Q. Ren, Y. Ren, T. L. Rhodes, J. Rice, T. D. Rognlien, J. C. Rost, W. L. Rowan, D. L. Rudakov, A. Salmi, B. S. Sammuli, C. M. Samuell, A. M. Sandorfi, C. Sang, O. J. Sauter, D. P. Schissel, L. Schmitz, O. Schmitz, E. J. Schuster, J. T. Scoville, A. Seltzman, I. Sfiligoi, M. Shafer, H. Shen, T. Shi, D. Shiraki, H. Si, D. R. Smith, S. P. Smith, J. A. Snipes, P. B. Snyder, E. R. Solano, W. M. Solomon, A. C. Sontag, V. A. Soukhanovskii, D. A. Spong, W. M. Stacey, G. M. Staebler, L. Stagner, B. Stahl, P. C. Stangeby, T. J. Stoltzfus-Dueck, D. P. Stotler, E. J. Strait, D. Su, L. E. Sugiyama, A. A. Sulyman, Y. Sun, C. Sung, W. A. Suttrop, Y. Suzuki, A. Svyatkovskiy, R. M. Sweeney, S. Taimourzadeh, M. Takechi, T. Tala, H. Tan, S. Tang, X. Tang, D. Taussig, G. Taylor, N. Z. Taylor, T. S. Taylor, A. Teklu, D. M. Thomas, M. B. Thomas, K. E. Thome, A. R. Thorman, R. A. Tinguely, B. J. Tobias, J. F. Tooker, H. Torreblanca, A. Torrezan De Sousa, G. L. Trevisan, D. Truong, F. Turco, A. D. Turnbull, E. A. Unterberg, P. Vaezi, P. J. Vail, M. A. Van Zeeland, M. Velasco Enriquez, M. C. Venkatesh, B. S. Victor, F. Volpe, M. R. Wade, M. L. Walker, J. R. Wall, G. M. Wallace, R. E. Waltz, G. Wang, H. Wang, Y. Wang, Z. Wang, F. Wang, S. H. Ward, J. G. Watkins, M. Watkins, W. P. Wehner, M. Weiland, D. B. Weisberg, A. S. Welander, A. E. White, R. B. White, D. Whyte, T. A. Wijkamp, R. Wilcox, T. Wilks, H. R. Wilson, A. Wingen, E. Wolfe, M. Wu, W. Wu, S. J. Wukitch, T. Xia, N. Xiang, B. Xiao, R. Xie, G. Xu, H. Xu, X. Xu, Z. Yan, Q. Yang, X. Yang, M. Yoshida, G. Yu, J. H. Yu, M. Yu, S. A. Zamperini, L. Zeng, B. Zhao, D. Zhao, H. Zhao, Y. Zhao, Y. Zhu, and B. Zywicki

Abstract

DIII-D research is addressing critical challenges in preparation for ITER and the next generation of fusion devices through focusing on plasma physics fundamentals that underpin key fusion goals, understanding the interaction of disparate core and boundary plasma physics, and developing integrated scenarios for achieving high performance fusion regimes. Fundamental investigations into fusion energy science find that anomalous dissipation of runaway electrons (RE) that arise following a disruption is likely due to interactions with RE-driven kinetic instabilities, some of which have been directly observed, opening a new avenue for RE energy dissipation using naturally excited waves. Dimensionless parameter scaling of intrinsic rotation and gyrokinetic simulations give a predicted ITER rotation profile with significant turbulence stabilization. Coherence imaging spectroscopy confirms near sonic flow throughout the divertor towards the target, which may account for the convection-dominated parallel heat flux. Core-boundary integration studies show that the small angle slot divertor achieves detachment at lower density and extends plasma cooling across the divertor target plate, which is essential for controlling heat flux and erosion. The Super H-mode regime has been extended to high plasma current (2.0 MA) and density to achieve very high pedestal pressures (∼30 kPa) and stored energy (3.2 MJ) with H 98y2 ≈ 1.6-2.4. In scenario work, the ITER baseline Q = 10 scenario with zero injected torque is found to have a fusion gain metric independent of current between q 95 = 2.8-3.7, and a lower limit of pedestal rotation for RMP ELM suppression has been found. In the wide pedestal QH-mode regime that exhibits improved performance and no ELMs, the start-up counter torque has been eliminated so that the entire discharge uses ≈0 injected torque and the operating space is more ITER-relevant. Finally, the high- (3.8) hybrid scenario has been extended to the high-density levels ne

Published
2019

28. Runaway electron synchrotron radiation in a vertically translated plasma.

Author

Hoppe, M., Papp, G., Wijkamp, T., Perek, A., Decker, J., Duval, B., Embreus, O., Fülöp, T., Sheikh, U.A., team, the TCV, and team, the EUROfusion MST1

Subjects
SYNCHROTRON radiation, PREDICTION theory, ELECTRONS, MAGNETIC fields, SYNCHROTRONS, TOKAMAKS
Abstract

Synchrotron radiation observed from runaway electrons (REs) in tokamaks depends upon the position and size of the RE beam, the RE energy and pitch distributions, as well as the location of the observer. We show experimental synchrotron images of a vertically moving RE beam sweeping past the detector in the Tokamak ŕ Configuration Variable (TCV) tokamak and compare it with predictions from the synthetic synchrotron diagnostic Soft. This experimental validation lends confidence to the theory underlying the synthetic diagnostics which are used for benchmarking theoretical models of and probing runaway dynamics. We present a comparison of synchrotron measurements in TCV with predictions of kinetic theory for runaway dynamics in uniform magnetic fields. We find that to explain the detected synchrotron emission, significant non-collisional pitch angle scattering as well as radial transport of REs would be needed. Such effects could be caused by the presence of magnetic perturbations, which should be further investigated in future TCV experiments. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

29. Validation of 2D T e and n e measurements made with Helium imaging spectroscopy in the volume of the TCV divertor

Author

Linehan, B. L., Perek, A., Duval, B. P., Bagnato, F., Blanchard, P., Colandrea, C., De Oliveira, H., Fevrier, O., Flom, E., Gorno, S., Goto, M., Marmar, E., Martinelli, L., Mathews, A., Munoz-Burgos, J., Mykytchuk, D., Offeddu, N., Oliveira, D. S., Reimerdes, H., Reiter, D., Schmitz, O., Terry, J. L., Theiler, C., Tsui, C. K., Vincent, B., Wijkamp, T., Wuethrich, C., and Zholobenko, W.

Subjects
helium collisional radiative modeling, density, scrape-off layer, tokamak divertor, edge, multi-spectral imaging, plasma boundary physics, plasmas, populations, recombination, tokamak diagnostics, neutral helium, electron-temperature, collisional-radiative model, divertor, tcv, implementation
Abstract

Multi-spectral imaging of helium atomic emission (HeMSI) has been used to create 2D poloidal maps of T-e and ne in TCV's divertor. To achieve these measurements, TCV's MANTIS multispectral cameras (Perek et al 2019 Rev. Sci. Instrum. 90 123514) simultaneously imaged four He I lines (two singlet and two triplet) and a He II line (468 nm) from passively present He and He+. The images, which were absolutely calibrated and covered the whole divertor region, were inverted through the assumption of toroidal symmetry to create emissivity profiles and, consequently, line-ratio profiles. A collisional-radiative model (CRM) was applied to the line-ratio profiles to produce 2D poloidal maps of Te and ne. The collisional-radiative modeling was accomplished with the Goto helium CRM code (Zholobenko et al 2018 Nucl. Fusion 58 126006, Zholobenko et al 2018 Technical Report, Goto 2003 J. Quant. Spectrosc. Radiat. Transfer 76 331-44) which accounts for electron-impact excitation (EIE) and deexcitation, and electron-ion recombination (EIR) with He+. The HeMSI T-e and ne measurements were compared with co-local Thomson scattering measurements. The two sets of measurements exhibited good agreement for ionizing plasmas: (5 eV 5 T-e 5 60 eV, and 2 x 10(18)m(-3) 5 ne 5 3 x 1019m(-3)) in the case of majority helium plasmas, and (10 eV 5 T-e 5 40 eV, 2 x 1018m-3 5 ne 5 3 x 10(19)m(-3)) in the case of majority deuterium plasmas. However, there were instances where HeMSI measurements diverged from Thomson scattering. When T-e 5 10 eV in majority deuterium plasmas, HeMSI deduced inaccurately high values of T-e. This disagreement cannot be rectified within the CRM's EIE and EIR framework. Second, on sporadic occasions within the private flux region, HeMSI produced erroneously high measurements of ne. Multi-spectral imaging of Helium emission has been demonstrated to produce accurate 2D poloidal maps of Te and ne within the divertor of a tokamak for plasma conditions relevant to contemporary divertor studies.

30. Characterisation of detachment in the MAST-U Super-X divertor using multi-wavelength imaging of 2D atomic and molecular emission processes

Author

Wijkamp, T. A., Allcock, J. S., Feng, X., Kool, B., Lipschultz, B., Verhaegh, K., Duval, B. P., Harrison, J. R., Kogan, L., Lonigro, N., Perek, A., Ryan, P., Sharples, R. M., Classen, I. G. J., Jaspers, R. J. E., and MAST Upgrade team

Subjects
state, super-x, mast upgrade, detachment, multispectral imaging, divertor
Abstract

In this work, we provide the first 2D spatially resolved description of radiative detachment in MAST-U Super-X L-mode divertor plasmas. The Super-X magnetic configuration was designed to achieve reduced heat- and particle loads at the divertor target compared to conventional exhaust solutions. We use filtered camera imaging to reconstruct 2D emissivity profiles in the poloidal plane for multiple atomic and molecular emission lines and bands. A set of deuterium fuelling scans is discussed that, together, span attached to deeply detached divertor states observed in MAST-U. Emissivity profiles facilitate separate analysis of locked-mode induced split branches of the scrape-off layer. Molecular deuterium Fulcher band emission front tracking reveals that the deuterium electron-impact ionisation front, for which it serves a proxy, detaches at different upstream electron densities in the split branches. Upon detachment of this ionisation front, Balmer emission attributed to molecular activated recombination appears near-target. We report a simultaneous radial broadening of the emission leg, consistent with previous SOLPS-ITER modelling. With increased fuelling this emission region detaches, implying electron temperatures below & SIM;1

31. Overview of the TCV tokamak experimental programme

Author

H. Reimerdes, M. Agostini, E. Alessi, S. Alberti, Y. Andrebe, H. Arnichand, J. Balbin, F. Bagnato, M. Baquero-Ruiz, M. Bernert, W. Bin, P. Blanchard, T.C. Blanken, J.A. Boedo, D. Brida, S. Brunner, C. Bogar, O. Bogar, T. Bolzonella, F. Bombarda, F. Bouquey, C. Bowman, D. Brunetti, J. Buermans, H. Bufferand, L. Calacci, Y. Camenen, S. Carli, D. Carnevale, F. Carpanese, F. Causa, J. Cavalier, M. Cavedon, J.A. Cazabonne, J. Cerovsky, R. Chandra, A. Chandrarajan Jayalekshmi, O. Chellaï, P. Chmielewski, D. Choi, G. Ciraolo, I.G.J. Classen, S. Coda, C. Colandrea, A. Dal Molin, P. David, M.R. de Baar, J. Decker, W. Dekeyser, H. de Oliveira, D. Douai, M. Dreval, M.G. Dunne, B.P. Duval, S. Elmore, O. Embreus, F. Eriksson, M. Faitsch, G. Falchetto, M. Farnik, A. Fasoli, N. Fedorczak, F. Felici, O. Février, O. Ficker, A. Fil, M. Fontana, E. Fransson, L. Frassinetti, I. Furno, D.S. Gahle, D. Galassi, K. Galazka, C. Galperti, S. Garavaglia, M. Garcia-Munoz, B. Geiger, M. Giacomin, G. Giruzzi, M. Gobbin, T. Golfinopoulos, T. Goodman, S. Gorno, G. Granucci, J.P. Graves, M. Griener, M. Gruca, T. Gyergyek, R. Haelterman, A. Hakola, W. Han, T. Happel, G. Harrer, J.R. Harrison, S. Henderson, G.M.D. Hogeweij, J.-P. Hogge, M. Hoppe, J. Horacek, Z. Huang, A. Iantchenko, P. Innocente, K. Insulander Björk, C. Ionita-Schrittweiser, H. Isliker, A. Jardin, R.J.E. Jaspers, R. Karimov, A.N. Karpushov, Y. Kazakov, M. Komm, M. Kong, J. Kovacic, O. Krutkin, O. Kudlacek, U. Kumar, R. Kwiatkowski, B. Labit, L. Laguardia, J.T. Lammers, E. Laribi, E. Laszynska, A. Lazaros, O. Linder, B. Linehan, B. Lipschultz, X. Llobet, J. Loizu, T. Lunt, E. Macusova, Y. Marandet, M. Maraschek, G. Marceca, C. Marchetto, S. Marchioni, E.S. Marmar, Y. Martin, L. Martinelli, F. Matos, R. Maurizio, M.-L. Mayoral, D. Mazon, V. Menkovski, A. Merle, G. Merlo, H. Meyer, K. Mikszuta-Michalik, P.A. Molina Cabrera, J. Morales, J.-M. Moret, A. Moro, D. Moulton, H. Muhammed, O. Myatra, D. Mykytchuk, F. Napoli, R.D. Nem, A.H. Nielsen, M. Nocente, S. Nowak, N. Offeddu, J. Olsen, F.P. Orsitto, O. Pan, G. Papp, A. Pau, A. Perek, F. Pesamosca, Y. Peysson, L. Pigatto, C. Piron, M. Poradzinski, L. Porte, T. Pütterich, M. Rabinski, H. Raj, J.J. Rasmussen, G.A. Rattá, T. Ravensbergen, D. Ricci, P. Ricci, N. Rispoli, F. Riva, J.F. Rivero-Rodriguez, M. Salewski, O. Sauter, B.S. Schmidt, R. Schrittweiser, S. Sharapov, U.A. Sheikh, B. Sieglin, M. Silva, A. Smolders, A. Snicker, C. Sozzi, M. Spolaore, A. Stagni, L. Stipani, G. Sun, T. Tala, P. Tamain, K. Tanaka, A. Tema Biwole, D. Terranova, J.L. Terry, D. Testa, C. Theiler, A. Thornton, A. Thrysøe, H. Torreblanca, C.K. Tsui, D. Vaccaro, M. Vallar, M. van Berkel, D. Van Eester, R.J.R. van Kampen, S. Van Mulders, K. Verhaegh, T. Verhaeghe, N. Vianello, F. Villone, E. Viezzer, B. Vincent, I. Voitsekhovitch, N.M.T. Vu, N. Walkden, T. Wauters, H. Weisen, N. Wendler, M. Wensing, F. Widmer, S. Wiesen, M. Wischmeier, T.A. Wijkamp, D. Wünderlich, C. Wüthrich, V. Yanovskiy, J. Zebrowski, the EUROfusion MST1 Team, EUROfusion MST1 Team, Control Systems Technology, Liquid metal heat shields, Science and Technology of Nuclear Fusion, Group Heemels, Mechanical Engineering, Data Mining, EAISI Health, ICMS Affiliated, EAISI High Tech Systems, Applied Physics and Science Education, Reimerdes, H, Agostini, M, Alessi, E, Alberti, S, Andrebe, Y, Arnichand, H, Balbin, J, Bagnato, F, Baquero-Ruiz, M, Bernert, M, Bin, W, Blanchard, P, Blanken, T, Boedo, J, Brida, D, Brunner, S, Bogar, C, Bogar, O, Bolzonella, T, Bombarda, F, Bouquey, F, Bowman, C, Brunetti, D, Buermans, J, Bufferand, H, Calacci, L, Camenen, Y, Carli, S, Carnevale, D, Carpanese, F, Causa, F, Cavalier, J, Cavedon, M, Cazabonne, J, Cerovsky, J, Chandra, R, Chandrarajan Jayalekshmi, A, Chellai, O, Chmielewski, P, Choi, D, Ciraolo, G, Classen, I, Coda, S, Colandrea, C, Dal Molin, A, David, P, De Baar, M, Decker, J, Dekeyser, W, De Oliveira, H, Douai, D, Dreval, M, Dunne, M, Duval, B, Elmore, S, Embreus, O, Eriksson, F, Faitsch, M, Falchetto, G, Farnik, M, Fasoli, A, Fedorczak, N, Felici, F, Fevrier, O, Ficker, O, Fil, A, Fontana, M, Fransson, E, Frassinetti, L, Furno, I, Gahle, D, Galassi, D, Galazka, K, Galperti, C, Garavaglia, S, Garcia-Munoz, M, Geiger, B, Giacomin, M, Giruzzi, G, Gobbin, M, Golfinopoulos, T, Goodman, T, Gorno, S, Granucci, G, Graves, J, Griener, M, Gruca, M, Gyergyek, T, Haelterman, R, Hakola, A, Han, W, Happel, T, Harrer, G, Harrison, J, Henderson, S, Hogeweij, G, Hogge, J, Hoppe, M, Horacek, J, Huang, Z, Iantchenko, A, Innocente, P, Insulander Bjork, K, Ionita-Schrittweiser, C, Isliker, H, Jardin, A, Jaspers, R, Karimov, R, Karpushov, A, Kazakov, Y, Komm, M, Kong, M, Kovacic, J, Krutkin, O, Kudlacek, O, Kumar, U, Kwiatkowski, R, Labit, B, Laguardia, L, Lammers, J, Laribi, E, Laszynska, E, Lazaros, A, Linder, O, Linehan, B, Lipschultz, B, Llobet, X, Loizu, J, Lunt, T, Macusova, E, Marandet, Y, Maraschek, M, Marceca, G, Marchetto, C, Marchioni, S, Marmar, E, Martin, Y, Martinelli, L, Matos, F, Maurizio, R, Mayoral, M, Mazon, D, Menkovski, V, Merle, A, Merlo, G, Meyer, H, Mikszuta-Michalik, K, Molina Cabrera, P, Morales, J, Moret, J, Moro, A, Moulton, D, Muhammed, H, Myatra, O, Mykytchuk, D, Napoli, F, Nem, R, Nielsen, A, Nocente, M, Nowak, S, Offeddu, N, Olsen, J, Orsitto, F, Pan, O, Papp, G, Pau, A, Perek, A, Pesamosca, F, Peysson, Y, Pigatto, L, Piron, C, Poradzinski, M, Porte, L, Putterich, T, Rabinski, M, Raj, H, Rasmussen, J, Ratta, G, Ravensbergen, T, Ricci, D, Ricci, P, Rispoli, N, Riva, F, Rivero-Rodriguez, J, Salewski, M, Sauter, O, Schmidt, B, Schrittweiser, R, Sharapov, S, Sheikh, U, Sieglin, B, Silva, M, Smolders, A, Snicker, A, Sozzi, C, Spolaore, M, Stagni, A, Stipani, L, Sun, G, Tala, T, Tamain, P, Tanaka, K, Tema Biwole, A, Terranova, D, Terry, J, Testa, D, Theiler, C, Thornton, A, Thrysoe, A, Torreblanca, H, Tsui, C, Vaccaro, D, Vallar, M, Van Berkel, M, Van Eester, D, Van Kampen, R, Van Mulders, S, Verhaegh, K, Verhaeghe, T, Vianello, N, Villone, F, Viezzer, E, Vincent, B, Voitsekhovitch, I, Vu, N, Walkden, N, Wauters, T, Weisen, H, Wendler, N, Wensing, M, Widmer, F, Wiesen, S, Wischmeier, M, Wijkamp, T, Wunderlich, D, Wuthrich, C, Yanovskiy, V, and Zebrowski, J

Subjects
Nuclear and High Energy Physics, Tokamak, feedback-control, Nuclear fusion, TCV, EUROfusion, ddc:620, plasmas, Condensed Matter Physics, tokamak, nuclear fusion, QC
Abstract

The tokamak à configuration variable (TCV) continues to leverage its unique shaping capabilities, flexible heating systems and modern control system to address critical issues in preparation for ITER and a fusion power plant. For the 2019–20 campaign its configurational flexibility has been enhanced with the installation of removable divertor gas baffles, its diagnostic capabilities with an extensive set of upgrades and its heating systems with new dual frequency gyrotrons. The gas baffles reduce coupling between the divertor and the main chamber and allow for detailed investigations on the role of fuelling in general and, together with upgraded boundary diagnostics, test divertor and edge models in particular. The increased heating capabilities broaden the operational regime to include T e/T i ∼ 1 and have stimulated refocussing studies from L-mode to H-mode across a range of research topics. ITER baseline parameters were reached in type-I ELMy H-modes and alternative regimes with ‘small’ (or no) ELMs explored. Most prominently, negative triangularity was investigated in detail and confirmed as an attractive scenario with H-mode level core confinement but an L-mode edge. Emphasis was also placed on control, where an increased number of observers, actuators and control solutions became available and are now integrated into a generic control framework as will be needed in future devices. The quantity and quality of results of the 2019–20 TCV campaign are a testament to its successful integration within the European research effort alongside a vibrant domestic programme and international collaborations.

Published
2022

32. DIII-D research towards establishing the scientific basis for future fusion reactors

Author

L. Abadie, T. W. Abrams, J. Ahn, T. Akiyama, P. Aleynikov, J. Allcock, E. O. Allen, S. Allen, J. P. Anderson, A. Ashourvan, M. E. Austin, J. Bak, K. K. Barada, N. Barbour, L. Bardoczi, J. Barr, J. L. Barton, E. M. Bass, D. Battaglia, L. R. Baylor, J. Beckers, E. A. Belli, J. W. Berkery, N. Bertelli, J. M. Bialek, J. A. Boedo, R. L. Boivin, P. T. Bonoli, A. Bortolon, M. D. Boyer, R. E. Brambila, B. Bray, D. P. Brennan, A. R. Briesemeister, S. A. Bringuier, M. W. Brookman, D. L. Brower, B. R. Brown, W. D. Brown, D. Buchenauer, M. G. Burke, K. H. Burrell, J. Butt, R. J. Buttery, I. Bykov, J. M. Candy, J. M. Canik, N. M. Cao, L. Carbajal Gomez, L. C. Carlson, T. N. Carlstrom, T. A. Carter, W. Cary, L. Casali, M. Cengher, V. S. Chan, B. Chen, J. Chen, M. Chen, R. Chen, Xi Chen, W. Choi, C. Chrobak, C. Chrystal, R. M. Churchill, M. Cianciosa, C. F. Clauser, M. Clement, J. Coburn, C. S. Collins, A. W. Cooper, B. M. Covele, J. W. Crippen, N. A. Crocker, B. J. Crowley, A. Dal Molin, E. M. Davis, J. S. deGrassie, C. A. del-Castillo-Negrete, L. F. Delgado-Aparicio, A. Diallo, S. J. Diem, R. Ding, S. Ding, W. Ding, J. L. Doane, D. C. Donovan, J. Drake, D. Du, H. Du, X. Du, V. Duarte, J. D. Duran, N. W. Eidietis, D. Elder, D. Eldon, W. Elwasif, T. E. Ely, K. M. Eng, K. Engelhorn, D. Ennis, K. Erickson, D. R. Ernst, T. E. Evans, M. E. Fenstermacher, N. M. Ferraro, J. R. Ferron, D. F. Finkenthal, P. A. Fisher, B. Fishler, S. M. Flanagan, J. A. Fooks, L. Frassinetti, H. G. Frerichs, Y. Fu, T. Fulop, Q. Gao, F. Garcia, A. M. Garofalo, A. Gattuso, L. Giacomelli, E. M. Giraldez, C. Giroud, F. Glass, P. Gohil, X. Gong, Y. A. Gorelov, R. S. Granetz, D. L. Green, C. M. Greenfield, B. A. Grierson, R. J. Groebner, W. H. Grosnickle, M. Groth, H. J. Grunloh, H. Y. Guo, W. Guo, J. Guterl, R. C. Hager, S. Hahn, F. D. Halpern, H. Han, M. J. Hansink, J. M. Hanson, J. Harris, S. R. Haskey, D. R. Hatch, W. W. Heidbrink, J. Herfindal, D. N. Hill, M. D. Hill, E. T. Hinson, C. T. Holcomb, C. G. Holland, L. D. Holland, E. M. Hollmann, A. M. Holm, R. Hong, M. Hoppe, S. Houshmandyar, J. Howard, N. T. Howard, Q. Hu, W. Hu, H. Huang, J. Huang, Y. Huang, G. A. Hughes, J. Hughes, D. A. Humphreys, A. W. Hyatt, K. Ida, V. Igochine, Y. In, S. Inoue, A. Isayama, R. C. Isler, V. A. Izzo, M. R. Jackson, A. E. Jarvinen, Y. Jeon, H. Ji, X. Jian, R. Jimenez, C. A. Johnson, I. Joseph, D. N. Kaczala, D. H. Kaplan, J. Kates-Harbeck, A. G. Kellman, D. H. Kellman, C. E. Kessel, K. Khumthong, C. C. Kim, H. Kim, J. Kim, K. Kim, S. H. Kim, W. Kimura, J. R. King, A. Kirk, K. Kleijwegt, M. Knolker, A. Kohn, E. Kolemen, M. Kostuk, G. J. Kramer, P. Kress, D. M. Kriete, R. J. La Haye, F. M. Laggner, H. Lan, M. J. Lanctot, R. Lantsov, L. L. Lao, C. J. Lasnier, C. Lau, K. Law, D. Lawrence, J. Le, R. L. Lee, M. Lehnen, R. Leon, A. W. Leonard, M. Lesher, J. A. Leuer, G. Li, K. Li, K. T. Liao, Z. Lin, C. Liu, F. Liu, Y. Liu, Z. Liu, S. Loch, N. C. Logan, J. M. Lohr, J. Lore, T. C. Luce, N. C. Luhmann, R. Lunsford, C. Luo, Z. Luo, L. Lupin-Jimenez, A. Lvovskiy, B. C. Lyons, X. Ma, R. Maingi, M. A. Makowski, P. Mantica, M. Manuel, M. W. Margo, A. Marinoni, E. Marmar, W. C. Martin, R. L. Masline, G. K. Matsunaga, D. M. Mauzey, P. S. Mauzey, J. T. Mcclenaghan, G. R. Mckee, A. G. Mclean, H. S. Mclean, E. Meier, S. J. Meitner, J. E. Menard, O. Meneghini, G. Merlo, W. H. Meyer, D. C. Miller, W. J. Miller, C. P. Moeller, K. J. Montes, M. A. Morales, S. Mordijck, A. Moser, R. A. Moyer, S. A. Muller, S. Munaretto, M. Murakami, C. J. Murphy, C. M. Muscatello, C. E. Myers, A. Nagy, G. A. Navratil, R. M. Nazikian, A. L. Neff, T. F. Neiser, A. Nelson, P. Nguyen, R. Nguyen, J. H. Nichols, M. Nocente, R. E. Nygren, R. C. O'Neill, T. Odstrcil, S. Ohdachi, M. Okabayashi, E. Olofsson, M. Ono, D. M. Orlov, T. H. Osborne, N. A. Pablant, D. C. Pace, R. R. Paguio, A. Pajares Martinez, C. Pan, A. Pankin, J. M. Park, J. Park, Y. Park, C. T. Parker, S. E. Parker, P. B. Parks, C. J. Pawley, C. A. Paz-Soldan, W. A. Peebles, B. G. Penaflor, T. W. Petrie, C. C. Petty, Y. Peysson, A. Y. Pigarov, D. A. Piglowski, R. I. Pinsker, P. Piovesan, N. Piper, R. A. Pitts, J. D. Pizzo, M. L. Podesta, F. M. Poli, D. Ponce, M. Porkolab, G. D. Porter, R. Prater, J. Qian, O. Ra, T. Rafiq, R. Raman, C. Rand, G. C. Randall, J. M. Rauch, C. Rea, M. L. Reinke, J. Ren, Q. Ren, Y. Ren, T. L. Rhodes, J. Rice, T. D. Rognlien, J. C. Rost, W. L. Rowan, D. L. Rudakov, A. Salmi, B. S. Sammuli, C. M. Samuell, A. M. Sandorfi, C. Sang, O. J. Sauter, D. P. Schissel, L. Schmitz, O. Schmitz, E. J. Schuster, J. T. Scoville, A. Seltzman, I. Sfiligoi, M. Shafer, H. Shen, T. Shi, D. Shiraki, H. Si, D. R. Smith, S. P. Smith, J. A. Snipes, P. B. Snyder, E. R. Solano, W. M. Solomon, A. C. Sontag, V. A. Soukhanovskii, D. A. Spong, W. M. Stacey, G. M. Staebler, L. Stagner, B. Stahl, P. C. Stangeby, T. J. Stoltzfus-Dueck, D. P. Stotler, E. J. Strait, D. Su, L. E. Sugiyama, A. A. Sulyman, Y. Sun, C. Sung, W. A. Suttrop, Y. Suzuki, A. Svyatkovskiy, R. M. Sweeney, S. Taimourzadeh, M. Takechi, T. Tala, H. Tan, S. Tang, X. Tang, D. Taussig, G. Taylor, N. Z. Taylor, T. S. Taylor, A. Teklu, D. M. Thomas, M. B. Thomas, K. E. Thome, A. R. Thorman, R. A. Tinguely, B. J. Tobias, J. F. Tooker, H. Torreblanca, A. Torrezan De Sousa, G. L. Trevisan, D. Truong, F. Turco, A. D. Turnbull, E. A. Unterberg, P. Vaezi, P. J. Vail, M. A. Van Zeeland, M. Velasco Enriquez, M. C. Venkatesh, B. S. Victor, F. Volpe, M. R. Wade, M. L. Walker, J. R. Wall, G. M. Wallace, R. E. Waltz, G. Wang, H. Wang, Y. Wang, Z. Wang, F. Wang, S. H. Ward, J. G. Watkins, M. Watkins, W. P. Wehner, M. Weiland, D. B. Weisberg, A. S. Welander, A. E. White, R. B. White, D. Whyte, T. A. Wijkamp, R. Wilcox, T. Wilks, H. R. Wilson, A. Wingen, E. Wolfe, M. Wu, W. Wu, S. J. Wukitch, T. Xia, N. Xiang, B. Xiao, R. Xie, G. Xu, H. Xu, X. Xu, Z. Yan, Q. Yang, X. Yang, M. Yoshida, G. Yu, J. H. Yu, M. Yu, S. A. Zamperini, L. Zeng, B. Zhao, D. Zhao, H. Zhao, Y. Zhao, Y. Zhu, B. Zywicki, Abadie, L, Abrams, T, Ahn, J, Akiyama, T, Aleynikov, P, Allcock, J, Allen, E, Allen, S, Anderson, J, Ashourvan, A, Austin, M, Bak, J, Barada, K, Barbour, N, Bardoczi, L, Barr, J, Barton, J, Bass, E, Battaglia, D, Baylor, L, Beckers, J, Belli, E, Berkery, J, Bertelli, N, Bialek, J, Boedo, J, Boivin, R, Bonoli, P, Bortolon, A, Boyer, M, Brambila, R, Bray, B, Brennan, D, Briesemeister, A, Bringuier, S, Brookman, M, Brower, D, Brown, B, Brown, W, Buchenauer, D, Burke, M, Burrell, K, Butt, J, Buttery, R, Bykov, I, Candy, J, Canik, J, Cao, N, Carbajal Gomez, L, Carlson, L, Carlstrom, T, Carter, T, Cary, W, Casali, L, Cengher, M, Chan, V, Chen, B, Chen, J, Chen, M, Chen, R, Chen, X, Choi, W, Chrobak, C, Chrystal, C, Churchill, R, Cianciosa, M, Clauser, C, Clement, M, Coburn, J, Collins, C, Cooper, A, Covele, B, Crippen, J, Crocker, N, Crowley, B, Dal Molin, A, Davis, E, Degrassie, J, del-Castillo-Negrete, C, Delgado-Aparicio, L, Diallo, A, Diem, S, Ding, R, Ding, S, Ding, W, Doane, J, Donovan, D, Drake, J, Du, D, Du, H, Du, X, Duarte, V, Duran, J, Eidietis, N, Elder, D, Eldon, D, Elwasif, W, Ely, T, Eng, K, Engelhorn, K, Ennis, D, Erickson, K, Ernst, D, Evans, T, Fenstermacher, M, Ferraro, N, Ferron, J, Finkenthal, D, Fisher, P, Fishler, B, Flanagan, S, Fooks, J, Frassinetti, L, Frerichs, H, Fu, Y, Fulop, T, Gao, Q, Garcia, F, Garofalo, A, Gattuso, A, Giacomelli, L, Giraldez, E, Giroud, C, Glass, F, Gohil, P, Gong, X, Gorelov, Y, Granetz, R, Green, D, Greenfield, C, Grierson, B, Groebner, R, Grosnickle, W, Groth, M, Grunloh, H, Guo, H, Guo, W, Guterl, J, Hager, R, Hahn, S, Halpern, F, Han, H, Hansink, M, Hanson, J, Harris, J, Haskey, S, Hatch, D, Heidbrink, W, Herfindal, J, Hill, D, Hill, M, Hinson, E, Holcomb, C, Holland, C, Holland, L, Hollmann, E, Holm, A, Hong, R, Hoppe, M, Houshmandyar, S, Howard, J, Howard, N, Hu, Q, Hu, W, Huang, H, Huang, J, Huang, Y, Hughes, G, Hughes, J, Humphreys, D, Hyatt, A, Ida, K, Igochine, V, In, Y, Inoue, S, Isayama, A, Isler, R, Izzo, V, Jackson, M, Jarvinen, A, Jeon, Y, Ji, H, Jian, X, Jimenez, R, Johnson, C, Joseph, I, Kaczala, D, Kaplan, D, Kates-Harbeck, J, Kellman, A, Kellman, D, Kessel, C, Khumthong, K, Kim, C, Kim, H, Kim, J, Kim, K, Kim, S, Kimura, W, King, J, Kirk, A, Kleijwegt, K, Knolker, M, Kohn, A, Kolemen, E, Kostuk, M, Kramer, G, Kress, P, Kriete, D, La Haye, R, Laggner, F, Lan, H, Lanctot, M, Lantsov, R, Lao, L, Lasnier, C, Lau, C, Law, K, Lawrence, D, Le, J, Lee, R, Lehnen, M, Leon, R, Leonard, A, Lesher, M, Leuer, J, Li, G, Li, K, Liao, K, Lin, Z, Liu, C, Liu, F, Liu, Y, Liu, Z, Loch, S, Logan, N, Lohr, J, Lore, J, Luce, T, Luhmann, N, Lunsford, R, Luo, C, Luo, Z, Lupin-Jimenez, L, Lvovskiy, A, Lyons, B, Ma, X, Maingi, R, Makowski, M, Mantica, P, Manuel, M, Margo, M, Marinoni, A, Marmar, E, Martin, W, Masline, R, Matsunaga, G, Mauzey, D, Mauzey, P, Mcclenaghan, J, Mckee, G, Mclean, A, Mclean, H, Meier, E, Meitner, S, Menard, J, Meneghini, O, Merlo, G, Meyer, W, Miller, D, Miller, W, Moeller, C, Montes, K, Morales, M, Mordijck, S, Moser, A, Moyer, R, Muller, S, Munaretto, S, Murakami, M, Murphy, C, Muscatello, C, Myers, C, Nagy, A, Navratil, G, Nazikian, R, Neff, A, Neiser, T, Nelson, A, Nguyen, P, Nguyen, R, Nichols, J, Nocente, M, Nygren, R, O'Neill, R, Odstrcil, T, Ohdachi, S, Okabayashi, M, Olofsson, E, Ono, M, Orlov, D, Osborne, T, Pablant, N, Pace, D, Paguio, R, Pajares Martinez, A, Pan, C, Pankin, A, Park, J, Park, Y, Parker, C, Parker, S, Parks, P, Pawley, C, Paz-Soldan, C, Peebles, W, Penaflor, B, Petrie, T, Petty, C, Peysson, Y, Pigarov, A, Piglowski, D, Pinsker, R, Piovesan, P, Piper, N, Pitts, R, Pizzo, J, Podesta, M, Poli, F, Ponce, D, Porkolab, M, Porter, G, Prater, R, Qian, J, Ra, O, Rafiq, T, Raman, R, Rand, C, Randall, G, Rauch, J, Rea, C, Reinke, M, Ren, J, Ren, Q, Ren, Y, Rhodes, T, Rice, J, Rognlien, T, Rost, J, Rowan, W, Rudakov, D, Salmi, A, Sammuli, B, Samuell, C, Sandorfi, A, Sang, C, Sauter, O, Schissel, D, Schmitz, L, Schmitz, O, Schuster, E, Scoville, J, Seltzman, A, Sfiligoi, I, Shafer, M, Shen, H, Shi, T, Shiraki, D, Si, H, Smith, D, Smith, S, Snipes, J, Snyder, P, Solano, E, Solomon, W, Sontag, A, Soukhanovskii, V, Spong, D, Stacey, W, Staebler, G, Stagner, L, Stahl, B, Stangeby, P, Stoltzfus-Dueck, T, Stotler, D, Strait, E, Su, D, Sugiyama, L, Sulyman, A, Sun, Y, Sung, C, Suttrop, W, Suzuki, Y, Svyatkovskiy, A, Sweeney, R, Taimourzadeh, S, Takechi, M, Tala, T, Tan, H, Tang, S, Tang, X, Taussig, D, Taylor, G, Taylor, N, Taylor, T, Teklu, A, Thomas, D, Thomas, M, Thome, K, Thorman, A, Tinguely, R, Tobias, B, Tooker, J, Torreblanca, H, Torrezan De Sousa, A, Trevisan, G, Truong, D, Turco, F, Turnbull, A, Unterberg, E, Vaezi, P, Vail, P, Van Zeeland, M, Velasco Enriquez, M, Venkatesh, M, Victor, B, Volpe, F, Wade, M, Walker, M, Wall, J, Wallace, G, Waltz, R, Wang, G, Wang, H, Wang, Y, Wang, Z, Wang, F, Ward, S, Watkins, J, Watkins, M, Wehner, W, Weiland, M, Weisberg, D, Welander, A, White, A, White, R, Whyte, D, Wijkamp, T, Wilcox, R, Wilks, T, Wilson, H, Wingen, A, Wolfe, E, Wu, M, Wu, W, Wukitch, S, Xia, T, Xiang, N, Xiao, B, Xie, R, Xu, G, Xu, H, Xu, X, Yan, Z, Yang, Q, Yang, X, Yoshida, M, Yu, G, Yu, J, Yu, M, Zamperini, S, Zeng, L, Zhao, B, Zhao, D, Zhao, H, Zhao, Y, Zhu, Y, and Zywicki, B

Subjects
Physics, Nuclear and High Energy Physics, fusion, model, Tokamak, DIII-D, Divertor, Mechanics, Plasma, Fusion power, Dissipation, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, law.invention, Pedestal, Heat flux, law, Physics::Plasma Physics, 0103 physical sciences, 010306 general physics, tokamak, plasma, energy
Abstract

DIII-D research is addressing critical challenges in preparation for ITER and the next generation of fusion devices through focusing on plasma physics fundamentals that underpin key fusion goals, understanding the interaction of disparate core and boundary plasma physics, and developing integrated scenarios for achieving high performance fusion regimes. Fundamental investigations into fusion energy science find that anomalous dissipation of runaway electrons (RE) that arise following a disruption is likely due to interactions with RE-driven kinetic instabilities, some of which have been directly observed, opening a new avenue for RE energy dissipation using naturally excited waves. Dimensionless parameter scaling of intrinsic rotation and gyrokinetic simulations give a predicted ITER rotation profile with significant turbulence stabilization. Coherence imaging spectroscopy confirms near sonic flow throughout the divertor towards the target, which may account for the convection-dominated parallel heat flux. Core-boundary integration studies show that the small angle slot divertor achieves detachment at lower density and extends plasma cooling across the divertor target plate, which is essential for controlling heat flux and erosion. The Super H-mode regime has been extended to high plasma current (2.0 MA) and density to achieve very high pedestal pressures (~30 kPa) and stored energy (3.2 MJ) with H 98y2 ≈ 1.6–2.4. In scenario work, the ITER baseline Q = 10 scenario with zero injected torque is found to have a fusion gain metric independent of current between q 95 = 2.8–3.7, and a lower limit of pedestal rotation for RMP ELM suppression has been found. In the wide pedestal QH-mode regime that exhibits improved performance and no ELMs, the start-up counter torque has been eliminated so that the entire discharge uses ≈0 injected torque and the operating space is more ITER-relevant. Finally, the high- (⩽3.8) hybrid scenario has been extended to the high-density levels necessary for radiating divertor operation, achieving ~40% divertor heat flux reduction using either argon or neon with P tot up to 15 MW.

Published
2019

Catalog

Books, media, physical & digital resources
See catalog results