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Measuring the plasma composition in tokamaks with metallic plasma-facing components

Part of: Focus on Fusion

Published online by Cambridge University Press:  07 October 2019

M. Sertoli Open the ORCID record for M. Sertoli [Opens in a new window] ,
Pedro Jorge Carvalho Open the ORCID record for Pedro Jorge Carvalho [Opens in a new window] ,
C. Giroud ,
S. Menmuir  and
JET Contributors
M. Sertoli*
Affiliation:
Max-Planck-Institut für Plasmaphysik, Boltzmannstrasse 2, D-85748 Garching, Germany CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, UK
Pedro Jorge Carvalho
Affiliation:
Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
C. Giroud
Affiliation:
CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, UK
S. Menmuir
Affiliation:
CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, UK
JET Contributors
Affiliation:
Max-Planck-Institut für Plasmaphysik, Boltzmannstrasse 2, D-85748 Garching, Germany CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, UK Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
*
†Email address for correspondence: marco.sertoli@ukaea.uk
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Abstract

In present and future magnetic confined fusion devices with metallic plasma-facing components (PFCs) such as JET-ILW and ITER, the calculation of the plasma composition must account for multiple impurities of a wide range of mass and charge, resolve their poloidal asymmetries and account for different central peakings for various elements. Single measurements of radiation and effective charge are not enough to characterize this complex system and a self-consistent analysis of data from multiple diagnostics is required. This contribution describes a method to calculate the plasma composition simultaneously accounting for contributions of up to two low-Z impurities, and two mid-/high-Z impurities. The analysis stems from methodologies explained in Sertoli et al. (Rev. Sci. Instrum., vol. 89 (11), 2018, 113501), expanded to include more impurities and to coherently analyse multiple diagnostics within the same framework. The example Ne-seeded JET-ILW hybrid discharge reported here shows that Be, Ne, Ni and W are necessary to simultaneously explain the observed soft X-ray emission, the W concentration measured by passive vacuum ultra-violet spectroscopy, the line-of-sight integrated measurement of the effective charge, the observed poloidal asymmetry of the soft X-ray (SXR) emission, the Ne density measured by charge-exchange-recombination spectroscopy and the line-of-sight integrals of the total radiation as measured by bolometry. This consistent picture of the elemental composition enables the calculation of the radial profiles of the effective charge, the dilution and total radiation. For the cases analysed up to now, these are often very different from the typical assumptions presently used when modelling JET-ILW discharges. This will affect, among others, the calculation of neutron rates, current density profile and heat transport. These considerations are of course valid for all present and future magnetic-controlled fusion devices which exhibit multi-material plasma-facing components, including ITER.

Keywords

fusion plasmaplasma diagnosticsplasma properties
Type
Research Article
Information
Journal of Plasma Physics , Volume 85 , Issue 5 , October 2019 , 905850504
Copyright
© The Author(s) 2019. Published by Cambridge University Press 

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Footnotes

‡

See the author list of ‘Overview of the JET preparation for Deuterium-Tritium Operation’ by E. Joffrin et al. to be published in Nuclear Fusion Special issue: overview and summary reports from the 27th Fusion Energy Conference (Ahmedabad, India, 22–27 October 2018).

References

Angioni, C., Casson, F. J., Mantica, P., Pütterich, T., Valisa, M., Belli, E. A., Bilato, R., Giroud, C., Helander, P.& JET Contributors 2015 The impact of poloidal asymmetries on tungsten transport in the core of JET H-mode plasmas. Phys. Plasmas 22 (5), 055902.Google Scholar
Angioni, C., Mantica, P., Pütterich, T., Valisa, M., Baruzzo, M., Belli, E. A., Belo, P., Casson, F. J., Challis, C., Drewelow, P. et al. & JET EFDA Contributors 2014 Tungsten transport in JET H-mode plasmas in hybrid scenario, experimental observations and modelling. Nucl. Fusion 54 (8), 083028.Google Scholar
Angioni, C., McDermott, R. M., Fable, E., Fischer, R., Pütterich, T., Ryter, F. & Tardini, G. 2011 Gyrokinetic modelling of electron and boron density profiles of H-mode plasmas in ASDEX upgrade. Nucl. Fusion 51 (2), 023006.Google Scholar
Asmussen, K., Fournier, K. B., Laming, J. M., Neu, R., Seely, J. F., Dux, R., Engelhardt, W., Fuchs, J. C.& ASDEX Upgrade Team 1998 Spectroscopic investigations of tungsten in the EUV region and the determination of its concentration in tokamaks. Nucl. Fusion 38 (7), 967–986.Google Scholar
Baylor, L. R., Burrell, K. H., Groebner, R. J., Houlberg, W. A., Ernst, D. P., Murakami, M. & Wade, M. R. 2004 Comparison of toroidal rotation velocities of different impurity ions in the diii-d tokamak. Phys. Plasmas 11 (6), 3100–3105.Google Scholar
Behringer, K. H., Carolan, P. G., Denne, B., Decker, G., Engelhardt, W., Forrest, M. J., Gill, R., Gottardi, N., Hawkes, N. C., Källne, E. et al. 1986 Impurity and radiation studies during the jet ohmic heating phase. Nucl. Fusion 26 (6), 751.Google Scholar
Beurskens, M. N. A., Schweinzer, J., Angioni, C., Burckhart, A., Challis, C. D., Chapman, I., Fischer, R., Flanagan, J., Frassinetti, L., Giroud, C. et al. 2013 The effect of a metal wall on confinement in JET and ASDEX Upgrade. Plasma Phys. Control. Fusion 55 (12), 124043.Google Scholar
Bonanomi, N., Mantica, P., Giroud, C., Angioni, C., Manas, P. & Menmuir, S. 2018 Light impurity transport in JET ILW l-mode plasmas. Nucl. Fusion 58 (3), 036009.Google Scholar
Bourdelle, C., Camenen, Y., Citrin, J., Marin, M., Casson, F. J., Koechl, F. & Maslov, M. 2018 Fast $h$ isotope and impurity mixing in ion-temperature-gradient turbulence. Nucl. Fusion 58 (7), 076028.Google Scholar
Breton, S., Casson, F. J., Bourdelle, C., Citrin, J., Baranov, Y., Camenen, Y., Challis, C., Corrigan, G., Garcia, J., Garzotti, L. et al. 2018a First principle integrated modeling of multi-channel transport including tungsten in JET. Nucl. Fusion 58 (9), 096003.Google Scholar
Breton, S., Casson, F. J., Bourdelle, C., Angioni, C., Belli, E., Camenen, Y., Citrin, J., Garbet, X., Sarazin, Y. & Sertoli, M. 2018b High $z$ neoclassical transport: application and limitation of analytical formulae for modelling JET experimental parameters. Phys. Plasmas 25 (1), 012303.Google Scholar
Casson, F. J., Angioni, C., Belli, E. A., Bilato, R., Mantica, P., Odstrcil, T., Pütterich, T., Valisa, M., Garzotti, L., Giroud, C. et al. & ASDEX Upgrade Team 2015 Theoretical description of heavy impurity transport and its application to the modelling of tungsten in JET and ASDEX Upgrade. Plasma Phys. Control. Fusion 57 (1), 014031.Google Scholar
Coenen, J. W., Sertoli, M., Brezinsek, S., Coffey, I., Dux, R., Giroud, C., Groth, M., Huber, A., Ivanova, D., Krieger, K. et al. 2013 Long-term evolution of the impurity composition and impurity events with the ITER-like wall at JET. Nucl. Fusion 53 (7), 073043.Google Scholar
Czarnecka, A., Zastrow, K.-D., Rzadkiewicz, J., Coffey, I. H., Lawson, K. D. & O’Mullane, M. G. 2011 Determination of metal impurity density, zeff and dilution on JET by VUV emission spectroscopy. Plasma Phys. Control. Fusion 53 (3), 035009.Google Scholar
Delgado-Aparicio, L., Stutman, D., Tritz, K., Volpe, F., Wong, K. L., Bell, R., Finkenthal, M., Fredrickson, E., Gerhardt, S. P., Kaye, S. et al. 2011 Impurity transport experiments and effects on MHD in the national spherical torus experiment (NSTX). Nucl. Fusion 51 (8), 083047.Google Scholar
Dux, R. & Peeters, A. G. 2000 Neoclassical impurity transport in the core of an ignited tokamak plasma. Nucl. Fusion 40 (10), 1721–1729.Google Scholar
Frassinetti, L., Beurskens, M. N. A., Scannell, R., Osborne, T. H., Flanagan, J., Kempenaars, M., Maslov, M., Pasqualotto, R., Walsh, M.& JET-EFDA Contributors 2012 Spatial resolution of the JET thomson scattering system. Rev. Sci. Instrum. 83 (1), 013506.Google Scholar
Giroud, C., Meigs, A. G., Negus, C. R., Zastrow, K.-D., Biewer, T. M. & Versloot, T. W. 2008 Impact of calibration technique on measurement accuracy for the jet core charge-exchange system. Rev. Sci. Instrum. 79 (10), 10F525.Google Scholar
Grierson, B. A., Chrystal, C., Haskey, S. R., Wang, W. X., Rhodes, T. L., McKee, G. R., Barada, K., Yuan, X., Nave, M. F. F., Ashourvan, A. et al. 2019 Main-ion intrinsic toroidal rotation across the itg/tem boundary in diii-d discharges during ohmic and electron cyclotron heating. Phys. Plasmas 26 (4), 042304.Google Scholar
Huber, A., McCormick, K., Andrew, P., Beaumont, P., Dalley, S., Fink, J., Fuchs, J. C., Fullard, K., Fundamenski, W., Ingesson, L. C. et al. 2007 Upgraded bolometer system on JET for improved radiation measurements. Fusion Engng Des. 82 (5), 1327–1334; Proceedings of the 24th Symposium on Fusion Technology.Google Scholar
Ingesson, L. C., Alper, B., Chen, H., Edwards, A. W., Fehmers, G. C., Fuchs, J. C., Giannella, R., Gill, R. D., Lauro-Taroni, L. & Romanelli, M. 1998 Soft x ray tomography during elms and impurity injection in JET. Nucl. Fusion 38 (11), 1675.Google Scholar
Kallenbach, A., Bernert, M., Dux, R., Casali, L., Eich, T., Giannone, L., Herrmann, A., McDermott, R., Mlynek, A., Müller, H. W. et al. 2013 Impurity seeding for tokamak power exhaust: from present devices via ITER to DEMO. Plasma Phys. Control. Fusion 55 (12), 124041.Google Scholar
Kallenbach, A., Neu, R., Dux, R., Fahrbach, H.-U., Fuchs, J. C., Giannone, L., Gruber, O., Herrmann, A., Lang, P. T., Lipschultz, B. et al. & ASDEX Upgrade Team 2005 Tokamak operation with high- $z$ plasma facing components. Plasma Phys. Control. Fusion 47 (12B), B207–B222.Google Scholar
Kappatou, A., McDermott, R. M., Angioni, C., Manas, P., Pütterich, T., Dux, R., Viezzer, E., Jaspers, R. J. E., Fischer, R., Dunne, M. G. et al. 2019 Understanding helium transport: experimental and theoretical investigations of low- $z$ impurity transport at ASDEX Upgrade. Nucl. Fusion 59 (5), 056014.Google Scholar
Lao, L. L., John, H. S., Stambaugh, R. D., Kellman, A. G. & Pfeiffer, W. 1985 Reconstruction of current profile parameters and plasma shapes in tokamaks. Nucl. Fusion 25 (11), 1611.Google Scholar
Lebschy, A.2018 Experimental characterization of the core plasma flow at the ASDEX Upgrade tokamak. Phd thesis, Technisce Universität München, also IPP report 18/16.Google Scholar
Lerche, E., Eester, D. V., Ongena, J., Mayoral, M.-L., Laxaback, M., Rimini, F., Argouarch, A., Beaumont, P., Blackman, T., Bobkov, V. et al. 2011 Optimizing ion-cyclotron resonance frequency heating for ITER: dedicated JET experiments. Plasma Phys. Control. Fusion 53 (12), 124019.Google Scholar
Loarte, A., Reinke, M. L., Polevoi, A. R., Hosokawa, M., Chilenski, M., Howard, N., Hubbard, A., Hughes, J. W., Rice, J. E., Walk, J. et al. 2015 Tungsten impurity transport experiments in alcator c-mod to address high priority research and development for iter. Phys. Plasmas 22 (5), 056117.Google Scholar
de la Luna, E., Sánchez, J., Tribaldos, V., Conway, G., Suttrop, W., Fessey, J., Prentice, R., Gowers, C., Chareau, J. M.& JET-EFDA contributors 2004 Electron cyclotron emission radiometer upgrade on the joint european torus (JET) tokamak. Rev. Sci. Instrum. 75 (10), 3831–3833.Google Scholar
Maslov, M., Beurskens, M. N. A., Kempenaars, M. & Flanagan, J. 2013 Status of the JET LIDAR thomson scattering diagnostic. J. Instrumentation 8 (11), C11009.Google Scholar
McDermott, R. M., Dux, R., Pütterich, T., Geiger, B., Kappatou, A., Lebschy, A., Bruhn, C., Cavedon, M., Frank, A., den Harder, N. et al. 2018 Evaluation of impurity densities from charge exchange recombination spectroscopy measurements at ASDEX Upgrade. Plasma Phys. Control. Fusion 60 (9), 095007.Google Scholar
Menmuir, S., Giroud, C., Biewer, T. M., Coffey, I. H., Delabie, E., Hawkes, N. C., Sertoli, M.& JET EFDA Contributors 2014 Carbon charge exchange analysis in the iter-like wall environment. Rev. Sci. Instrum. 85 (11), 11E412.Google Scholar
Odstrcil, T., Pütterich, T., Angioni, C., Bilato, R., Gude, A., Odstrcil, M., Team, A.& the EUROfusion MST1 team 2018 The physics of $w$ transport illuminated by recent progress in $w$ density diagnostics at ASDEX Upgrade. Plasma Phys. Control. Fusion 60 (1), 014003.Google Scholar
Ongena, J. P. H. E., Voitsekhovitch, I., Evrard, M. & McCune, D. 2012 Numerical transport codes. Fusion Sci. Technol. 61 (2T), 180–189.Google Scholar
Pacher, G. W., Pacher, H. D., Janeschitz, G., Kukushkin, A. S., Kotov, V. & Reiter, D. 2007 Modelling of DEMO core plasma consistent with SOL/divertor simulations for long-pulse scenarios with impurity seeding. Nucl. Fusion 47 (5), 469–478.Google Scholar
Pasqualotto, R., Nielsen, P., Gowers, C., Beurskens, M., Kempenaars, M., Carlstrom, T., Johnson, D.& JET-EFDA Contributors 2004 High resolution thomson scattering for joint european torus (JET). Rev. Sci. Instrum. 75 (10), 3891–3893.Google Scholar
Pucella, G., Giovannozzi, E., Challis, C. D., Chomiczewska, A., Giroud, C., Hobirk, J., Joffrin, E., Kappatou, A., Keeling, D. L., King, D. et al. & JET Contributors 2019 Evaluation of the effective charge profile and analysis of the effect of the impurity mixture on the current density and safety factor profiles. In 3rd Asia-Pacific Conference on Plasma Physics 2019.Google Scholar
Pütterich, T., Dux, R., Beurskens, M. N. A., Bobkov, V., Brezinsek, S., Bucalossi, J., Coenen, J. W., Coffey, I., Czarnecka, A., Giroud, C. et al. & JET EFDA contributors 2012 Tungsten screening and impurity control in JET. In Proceedings of the 24th IAEA Conference Fusion Energy (CD-Rom), San Diego, USA, October 2012, p. EX/P315. Vienna: IAEA.Google Scholar
Pütterich, T., Neu, R., Dux, R., Whiteford, A. D., O’Mullane, M. G.& ASDEX Upgrade Team 2008 Modelling of measured tungsten spectra from ASDEX Upgrade and predictions for iter. Plasma Phys. Control. Fusion 50 (8), 085016.Google Scholar
Pütterich, T., Fable, E., Dux, R., O’Mullane, M., Neu, R. & Siccinio, M. 2019 Determination of the tolerable impurity concentrations in a fusion reactor using a consistent set of cooling factors. Nucl. Fusion 59 (5), 056013.Google Scholar
Rathgeber, S. K., Fischer, R., Fietz, S., Hobirk, J., Kallenbach, A., Meister, H., Pütterich, T., Ryter, F., Tardini, G. & Wolfrum, E. 2010 Estimation of profiles of the effective ion charge at ASDEX Upgrade with integrated data analysis. Plasma Phys. Control. Fusion 52 (9), 095008.Google Scholar
Reinke, M. L., Hutchinson, I. H., Rice, J. E., Howard, N. T., Bader, A., Wukitch, S., Lin, Y., Pace, D. C., Hubbard, A., Hughes, J. W. et al. 2012 Poloidal variation of high- $z$ impurity density due to hydrogen minority ion cyclotron resonance heating on alcator c-mod. Plasma Phys. Control. Fusion 54 (4), 045004.Google Scholar
Schwob, J. L., Wouters, A. W., Suckewer, S. & Finkenthal, M. 1987 High-resolution duo-multichannel soft x-ray spectrometer for tokamak plasma diagnostics. Rev. Sci. Instrum. 58 (9), 1601–1615.Google Scholar
Sertoli, M., Angioni, C., Odstrcil, T.& ASDEX Upgrade Team, and EUROFusion MST1 Team 2017 Parametric dependencies of the experimental tungsten transport coefficients in icrh and ecrh assisted ASDEX Upgrade H-modes. Phys. Plasmas 24 (11), 112503.Google Scholar
Sertoli, M., Dux, R., Pütterich, T.& ASDEX Upgrade Team 2015 Modification of impurity transport in the presence of saturated $(m,n)=(1,1)$ mhd activity at ASDEX Upgrade. Plasma Phys. Control. Fusion 57 (7), 075004.Google Scholar
Sertoli, M., Flanagan, J., Maslov, M., Maggi, C., Coffey, I., Giroud, C., Menmuir, S., Carvalho, P., Shaw, A., Delabie, E.& JET Contributors 2018 Determination of 2d poloidal maps of the intrinsic w density for transport studies in JET-ILW. Rev. Sci. Instrum. 89 (11), 113501.Google Scholar
Shumack, A. E., Rzadkiewicz, J., Chernyshova, M., Jakubowska, K., Scholz, M., Byszuk, A., Cieszewski, R., Czarski, T., Dominik, W., Karpinski, L. et al. 2014 X-ray crystal spectrometer upgrade for ITER-like wall experiments at JET. Rev. Sci. Instrum. 85 (11), 11E425.Google Scholar
Tardini, G., Fischer, R., Jenko, F., Kallenbach, A., McDermott, R. M., Pütterich, T., Rathgeber, S. K., Schneller, M., Schweinzer, J., Sips, A. C. C. et al. 2012 Core transport analysis of nitrogen seeded H-mode discharges in the ASDEX Upgrade. Plasma Phys. Control. Fusion 55 (1), 015010.Google Scholar
Zagórski, R., Ivanova-Stanik, R. I. & Stankiewicz, R. 2013 Simulations with the COREDIV code of DEMO discharges. Nucl. Fusion 53 (7), 073030.Google Scholar