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36 results on '"Kazakov, Ye.O."'

2. Experiments on excitation of Alfvén eigenmodes by alpha-particles with bump-on-tail distribution in JET DTE2 plasmas.

Author

Sharapov, S.E., Oliver, H.J.C., Garcia, J., Keeling, D.L., Dreval, M., Goloborod'Ko, V., Kazakov, Ye.O., Kiptily, V.G., Štancar, Ž., Bonofiglo, P.J., Coelho, R., Craciunescu, T., Ferreira, J., Figueiredo, A., Fil, N., Fitzgerald, M., Nabais, F., Nocente, M., Puglia, P.G., and Rivero-Rodriguez, J.

Subjects
PLASMA jets, PLASMA beam injection heating, NEUTRAL beams, SOFT X rays, ION beams, REFLECTOMETRY, INTERFEROMETRY
Abstract

Dedicated experiments were performed in JET DTE2 plasmas for obtaining an α -particle bump-on-tail (BOT) distribution aiming at exciting Alfvén eigenmodes (AEs). Neutral beam injection-only heating with modulated power was used so that fusion-born α -particles were the only ions present in the MeV energy range in these DT plasmas. The beam power modulation on a time scale shorter than the α -particle slowing down time was chosen for modulating the α -particle source and thus sustaining a BOT in the α -particle distribution. High-frequency modes in the toroidicity-induced Alfven eigenmode (TAE) frequency range and multiple short-lived modes in a wider frequency range have been detected in these DT discharges with interferometry, soft x-ray cameras, and reflectometry. The modes observed were localised close to the magnetic axis, and were not seen in the Mirnov coils. Analysis with the TRANSP and Fokker-Planck FIDIT codes confirms that α -particle distributions with BOT in energy were achieved during some time intervals in these discharges though no clear correlation was found between the times of the high-frequency mode excitation and the BOT time intervals. The combined magneto-hydrodynamic (MHD) and kinetic modelling studies show that the high-frequency mode in the TAE frequency range is best fitted with a TAE of toroidal mode number n = 9. This mode is driven mostly by the on-axis beam ions while the smaller drive due to the pressure gradient of α -particles allows overcoming the marginal stability and exciting the mode (Oliver et al 2023 Nucl. Fusion submitted). The observed multiple short-lived modes in a wider frequency range are identified as the on-axis kinetic AEs predicted in Rosenbluth and Rutherford (1975 Phys. Rev. Lett. 34 1428). [ABSTRACT FROM AUTHOR]

Published
2023
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3. FUSION RESEARCH IN STELLARATOR DEPARTMENT OF IPP NSC KIPT

Author

Moiseenko, V.Е., primary, Dreval, M.B., additional, Kovtun, Yu.V., additional, Kulyk, Yu.S., additional, Glazunov, G.P., additional, Kazakov, Ye.O., additional, Ongena, J., additional, Sharapov, S.E., additional, Thomsen, H., additional, and Garkusha, I.E., additional

Published
2022
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4. Overview of W7-X ECRH Results

Author

Laqua H.P., Baldzuhn J., Braune H., Bozhenkov S., Brunner K.J., Kazakov Ye.O., Marsen S., Moseev D., Stange T., Wolf R.C., and Zanini M.

Subjects
Physics, QC1-999
Abstract

In its second operation phase (OP1.2a) W7-X was equipped with full 3d island divertor and an upgraded ECRH-system of 10 gyrotrons with a total port through power of 7 MW. The combination of pellet fueling and high density ECRH enabled to explore density above 1 1020 m-3. In particular with the O2-polarisation combined with a multi-pass reflector tile system a density of up to 1.4 1020 m-3 was achieved. At slightly lower densities high core beta values and record values of the fusion tripple product of 0.66 1020 m-3 keVs for stellarators were reached. In addition routine plasma start-up and ECRH wall conditioning were performed. The island divertor enables to demonstrate the intrinsic steady state capabilities of W7-X, where stationary discharges of up to 30s were demonstrated being only limited by the heat capacity of the uncooled divertor. With the flexible ECRH launch system current density profile variations were used for MHD stability investigations. Here by fine-tuning of the ECCD profile different MHD activity could be triggered.

Published
2019
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5. Simultaneous measurements of unstable and stable Alfvén eigenmodes in JET

Author

Tinguely, R.A., primary, Gonzalez-Martin, J., additional, Puglia, P.G., additional, Fil, N., additional, Dowson, S., additional, Porkolab, M., additional, Kumar, I., additional, Podestà, M., additional, Baruzzo, M., additional, Fasoli, A., additional, Kazakov, Ye.O., additional, Nave, M.F.F., additional, Nocente, M., additional, Ongena, J., additional, Štancar, Ž., additional, and Contributors, JET, additional

Published
2022
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6. FUSION RESEARCH IN STELLARATOR DEPARTMENT OF IPP NSC KIPT

Author

Moiseyenko, Volodymyr, Dreval, M.B., Kovtun, Yu.V., Kulyk, Yu.S., Glazunov, G.P., Kazakov, Ye.O., Ongena, J., Sharapov, S.E., Thomsen, H., Garkusha, I.E., Moiseyenko, Volodymyr, Dreval, M.B., Kovtun, Yu.V., Kulyk, Yu.S., Glazunov, G.P., Kazakov, Ye.O., Ongena, J., Sharapov, S.E., Thomsen, H., and Garkusha, I.E.

Abstract

This paper briefly describes intrinsic and collaborative scientific activities in the Stellarator Department of theInstitute of Plasma Physics of the National Science Center “Kharkov Institute of Physics and Technology” in lasttwo years. These activities include experiments on JET tokamak, stellarators Wendelstein 7-X and Uragan-2M,TOMAS toroidal device and theoretical studies related to modeling of radio-frequency fields in plasma andconceptual development of the stellarator-mirror fission-fusion hybrid.

Published
2022
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7. High-frequency reversed-shear Alfvén eigenmodes in fast-ion experiments on JET

Author

Dreval, M., Sharapov, S.E., Kazakov, Ye.O., Ongena, J., Nocente, M., Calado, Ceclia R. C., Coelho, R., Ferreira, J., Figueiredo, A., Fitzgerald, M., Garcia, J., Giroud, C., Hawkes, N.C., Kiptily, V.G., Nabais, F., Nave, M.F.F., Weisen, H., Craciunescu, T., Salewski, M., Stancar, Z., Dreval, M., Sharapov, S.E., Kazakov, Ye.O., Ongena, J., Nocente, M., Calado, Ceclia R. C., Coelho, R., Ferreira, J., Figueiredo, A., Fitzgerald, M., Garcia, J., Giroud, C., Hawkes, N.C., Kiptily, V.G., Nabais, F., Nave, M.F.F., Weisen, H., Craciunescu, T., Salewski, M., and Stancar, Z.

Published
2022

8. Overview of JET results for optimising ITER operation

Author

Mailloux, J., primary, Abid, N., additional, Abraham, K., additional, Abreu, P., additional, Adabonyan, O., additional, Adrich, P., additional, Afanasev, V., additional, Afzal, M., additional, Ahlgren, T., additional, Aho-Mantila, L., additional, Aiba, N., additional, Airila, M., additional, Akhtar, M., additional, Albanese, R., additional, Alderson-Martin, M., additional, Alegre, D., additional, Aleiferis, S., additional, Aleksa, A., additional, Alekseev, A.G., additional, Alessi, E., additional, Aleynikov, P., additional, Algualcil, J., additional, Ali, M., additional, Allinson, M., additional, Alper, B., additional, Alves, E., additional, Ambrosino, G., additional, Ambrosino, R., additional, Amosov, V., additional, Sundén, E.Andersson, additional, Andrew, P., additional, Angelini, B.M., additional, Angioni, C., additional, Antoniou, I., additional, Appel, L.C., additional, Appelbee, C., additional, Aria, S., additional, Ariola, M., additional, Artaserse, G., additional, Arter, W., additional, Artigues, V., additional, Asakura, N., additional, Ash, A., additional, Ashikawa, N., additional, Aslanyan, V., additional, Astrain, M., additional, Asztalos, O., additional, Auld, D., additional, Auriemma, F., additional, Austin, Y., additional, Avotina, L., additional, Aymerich, E., additional, Baciero, A., additional, Bairaktaris, F., additional, Balbin, J., additional, Balbinot, L., additional, Balboa, I., additional, Balden, M., additional, Balshaw, C., additional, Balshaw, N., additional, Bandaru, V.K., additional, Banks, J., additional, Baranov, Yu.F., additional, Barcellona, C., additional, Barnard, A., additional, Barnard, M., additional, Barnsley, R., additional, Barth, A., additional, Baruzzo, M., additional, Barwell, S., additional, Bassan, M., additional, Batista, A., additional, Batistoni, P., additional, Baumane, L., additional, Bauvir, B., additional, Baylor, L., additional, Beaumont, P.S., additional, Beckett, D., additional, Begolli, A., additional, Beidler, M., additional, Bekris, N., additional, Beldishevski, M., additional, Belli, E., additional, Belli, F., additional, Belonohy, É., additional, Ben Yaala, M., additional, Benayas, J., additional, Bentley, J., additional, Bergsåker, H., additional, Bernardo, J., additional, Bernert, M., additional, Berry, M., additional, Bertalot, L., additional, Betar, H., additional, Beurskens, M., additional, Bickerton, S., additional, Bieg, B., additional, Bielecki, J., additional, Bierwage, A., additional, Biewer, T., additional, Bilato, R., additional, Bílková, P., additional, Birkenmeier, G., additional, Bishop, H., additional, Bizarro, J.P.S., additional, Blackburn, J., additional, Blanchard, P., additional, Blatchford, P., additional, Bobkov, V., additional, Boboc, A., additional, Bohm, P., additional, Bohm, T., additional, Bolshakova, I., additional, Bolzonella, T., additional, Bonanomi, N., additional, Bonfiglio, D., additional, Bonnin, X., additional, Bonofiglo, P., additional, Boocock, S., additional, Booth, A., additional, Booth, J., additional, Borba, D., additional, Borodin, D., additional, Borodkina, I., additional, Boulbe, C., additional, Bourdelle, C., additional, Bowden, M., additional, Boyd, K., additional, Mihalić, I.Božičević, additional, Bradnam, S.C., additional, Braic, V., additional, Brandt, L., additional, Bravanec, R., additional, Breizman, B., additional, Brett, A., additional, Brezinsek, S., additional, Brix, M., additional, Bromley, K., additional, Brown, B., additional, Brunetti, D., additional, Buckingham, R., additional, Buckley, M., additional, Budny, R., additional, Buermans, J., additional, Bufferand, H., additional, Buratti, P., additional, Burgess, A., additional, Buscarino, A., additional, Busse, A., additional, Butcher, D., additional, Cal, E.de la, additional, Calabrò, G., additional, Calacci, L., additional, Calado, R., additional, Camenen, Y., additional, Canal, G., additional, Cannas, B., additional, Cappelli, M., additional, Carcangiu, S., additional, Card, P., additional, Cardinali, A., additional, Carman, P., additional, Carnevale, D., additional, Carr, M., additional, Carralero, D., additional, Carraro, L., additional, Carvalho, I.S., additional, Carvalho, P., additional, Casiraghi, I., additional, Casson, F.J., additional, Castaldo, C., additional, Catalan, J.P., additional, Catarino, N., additional, Causa, F., additional, Cavedon, M., additional, Cecconello, M., additional, Challis, C.D., additional, Chamberlain, B., additional, Chang, C.S., additional, Chankin, A., additional, Chapman, B., additional, Chernyshova, M., additional, Chiariello, A., additional, Chmielewski, P., additional, Chomiczewska, A., additional, Chone, L., additional, Ciraolo, G., additional, Ciric, D., additional, Citrin, J., additional, Ciupinski, Ł., additional, Clark, M., additional, Clarkson, R., additional, Clements, C., additional, Cleverly, M., additional, Coad, J.P., additional, Coates, P., additional, Cobalt, A., additional, Coccorese, V., additional, Coelho, R., additional, Coenen, J.W., additional, Coffey, I.H., additional, Colangeli, A., additional, Colas, L., additional, Collins, C., additional, Collins, J., additional, Collins, S., additional, Conka, D., additional, Conroy, S., additional, Conway, B., additional, Conway, N.J., additional, Coombs, D., additional, Cooper, P., additional, Cooper, S., additional, Corradino, C., additional, Corrigan, G., additional, Coster, D., additional, Cox, P., additional, Craciunescu, T., additional, Cramp, S., additional, Crapper, C., additional, Craven, D., additional, Craven, R., additional, Esposito, M.Crialesi, additional, Croci, G., additional, Croft, D., additional, Croitoru, A., additional, Crombé, K., additional, Cronin, T., additional, Cruz, N., additional, Crystal, C., additional, Cseh, G., additional, Cufar, A., additional, Cullen, A., additional, Curuia, M., additional, Czarski, T., additional, Dabirikhah, H., additional, Molin, A.Dal, additional, Dale, E., additional, Dalgliesh, P., additional, Dalley, S., additional, Dankowski, J., additional, David, P., additional, Davies, A., additional, Davies, S., additional, Davis, G., additional, Dawson, K., additional, Dawson, S., additional, Day, I.E., additional, De Bock, M., additional, De Temmerman, G., additional, De Tommasi, G., additional, Deakin, K., additional, Deane, J., additional, Dejarnac, R., additional, Del Sarto, D., additional, Delabie, E., additional, Del-Castillo-Negrete, D., additional, Dempsey, A., additional, Dendy, R.O., additional, Devynck, P., additional, Di Siena, A., additional, Di Troia, C., additional, Dickson, T., additional, Dinca, P., additional, Dittmar, T., additional, Dobrashian, J., additional, Doerner, R.P., additional, Donné, A.J.H., additional, Dorling, S., additional, Dormido-Canto, S., additional, Douai, D., additional, Dowson, S., additional, Doyle, R., additional, Dreval, M., additional, Drewelow, P., additional, Drews, P., additional, Drummond, G., additional, Duckworth, Ph., additional, Dudding, H., additional, Dumont, R., additional, Dumortier, P., additional, Dunai, D., additional, Dunatov, T., additional, Dunne, M., additional, Ďuran, I., additional, Durodié, F., additional, Dux, R., additional, Dvornova, A., additional, Eastham, R., additional, Edwards, J., additional, Eich, Th., additional, Eichorn, A., additional, Eidietis, N., additional, Eksaeva, A., additional, El Haroun, H., additional, Ellwood, G., additional, Elsmore, C., additional, Embreus, O., additional, Emery, S., additional, Ericsson, G., additional, Eriksson, B., additional, Eriksson, F., additional, Eriksson, J., additional, Eriksson, L.G., additional, Ertmer, S., additional, Esquembri, S., additional, Esquisabel, A.L., additional, Estrada, T., additional, Evans, G., additional, Evans, S., additional, Fable, E., additional, Fagan, D., additional, Faitsch, M., additional, Falessi, M., additional, Fanni, A., additional, Farahani, A., additional, Farquhar, I., additional, Fasoli, A., additional, Faugeras, B., additional, Fazinić, S., additional, Felici, F., additional, Felton, R., additional, Fernandes, A., additional, Fernandes, H., additional, Ferrand, J., additional, Ferreira, D.R., additional, Ferreira, J., additional, Ferrò, G., additional, Fessey, J., additional, Ficker, O., additional, Field, A.R., additional, Figueiredo, A., additional, Figueiredo, J., additional, Fil, A., additional, Fil, N., additional, Finburg, P., additional, Fiorucci, D., additional, Fischer, U., additional, Fishpool, G., additional, Fittill, L., additional, Fitzgerald, M., additional, Flammini, D., additional, Flanagan, J., additional, Flinders, K., additional, Foley, S., additional, Fonnesu, N., additional, Fontana, M., additional, Fontdecaba, J.M., additional, Forbes, S., additional, Formisano, A., additional, Fornal, T., additional, Fortuna, L., additional, Fortuna-Zalesna, E., additional, Fortune, M., additional, Fowler, C., additional, Fransson, E., additional, Frassinetti, L., additional, Freisinger, M., additional, Fresa, R., additional, Fridström, R., additional, Frigione, D., additional, Fülöp, T., additional, Furseman, M., additional, Fusco, V., additional, Futatani, S., additional, Gadariya, D., additional, Gál, K., additional, Galassi, D., additional, Gałązka, K., additional, Galeani, S., additional, Gallart, D., additional, Galvão, R., additional, Gao, Y., additional, Garcia, J., additional, García-Muñoz, M., additional, Gardener, M., additional, Garzotti, L., additional, Gaspar, J., additional, Gatto, R., additional, Gaudio, P., additional, Gear, D., additional, Gebhart, T., additional, Gee, S., additional, Gelfusa, M., additional, George, R., additional, Gerasimov, S.N., additional, Gervasini, G., additional, Gethins, M., additional, Ghani, Z., additional, Gherendi, M., additional, Ghezzi, F., additional, Giacalone, J.C., additional, Giacomelli, L., additional, Giacometti, G., additional, Gibson, C., additional, Gibson, K.J., additional, Gil, L., additional, Gillgren, A., additional, Gin, D., additional, Giovannozzi, E., additional, Giroud, C., additional, Glen, R., additional, Glöggler, S., additional, Goff, J., additional, Gohil, P., additional, Goloborodko, V., additional, Gomes, R., additional, Gonçalves, B., additional, Goniche, M., additional, Goodyear, A., additional, Gore, S., additional, Gorini, G., additional, Görler, T., additional, Gotts, N., additional, Goulding, R., additional, Gow, E., additional, Graham, B., additional, Graves, J.P., additional, Greuner, H., additional, Grierson, B., additional, Griffiths, J., additional, Griph, S., additional, Grist, D., additional, Gromelski, W., additional, Groth, M., additional, Grove, R., additional, Gruca, M., additional, Guard, D., additional, Gupta, N., additional, Gurl, C., additional, Gusarov, A., additional, Hackett, L., additional, Hacquin, S., additional, Hager, R., additional, Hägg, L., additional, Hakola, A., additional, Halitovs, M., additional, Hall, S., additional, Hall, S.A., additional, Hallworth-Cook, S., additional, Ham, C.J., additional, Hamaguchi, D., additional, Hamed, M., additional, Hamlyn-Harris, C., additional, Hammond, K., additional, Harford, E., additional, Harrison, J.R., additional, Harting, D., additional, Hatano, Y., additional, Hatch, D.R., additional, Haupt, T., additional, Hawes, J., additional, Hawkes, N.C., additional, Hawkins, J., additional, Hayashi, T., additional, Hazael, S., additional, Hazel, S., additional, Heesterman, P., additional, Heidbrink, B., additional, Helou, W., additional, Hemming, O., additional, Henderson, S.S., additional, Henriques, R.B., additional, Hepple, D., additional, Herfindal, J., additional, Hermon, G., additional, Hill, J., additional, Hillesheim, J.C., additional, Hizanidis, K., additional, Hjalmarsson, A., additional, Ho, A., additional, Hobirk, J., additional, Hoenen, O., additional, Hogben, C., additional, Hollingsworth, A., additional, Hollis, S., additional, Hollmann, E., additional, Hölzl, M., additional, Homan, B., additional, Hook, M., additional, Hopley, D., additional, Horáček, J., additional, Horsley, D., additional, Horsten, N., additional, Horton, A., additional, Horton, L.D., additional, Horvath, L., additional, Hotchin, S., additional, Howell, R., additional, Hu, Z., additional, Huber, A., additional, Huber, V., additional, Huddleston, T., additional, Huijsmans, G.T.A., additional, Huynh, P., additional, Hynes, A., additional, Iliasova, M., additional, Imrie, D., additional, Imríšek, M., additional, Ingleby, J., additional, Innocente, P., additional, Insulander Björk, K., additional, Isernia, N., additional, Ivanova-Stanik, I., additional, Ivings, E., additional, Jablonski, S., additional, Jachmich, S., additional, Jackson, T., additional, Jacquet, P., additional, Järleblad, H., additional, Jaulmes, F., additional, Rodriguez, J.Jenaro, additional, Jepu, I., additional, Joffrin, E., additional, Johnson, R., additional, Johnson, T., additional, Johnston, J., additional, Jones, C., additional, Jones, G., additional, Jones, L., additional, Jones, N., additional, Jones, T., additional, Joyce, A., additional, Juarez, R., additional, Juvonen, M., additional, Kalniņa, P., additional, Kaltiaisenaho, T., additional, Kaniewski, J., additional, Kantor, A., additional, Kappatou, A., additional, Karhunen, J., additional, Karkinsky, D., additional, Kashchuk, Yu, additional, Kaufman, M., additional, Kaveney, G., additional, Kazakov, Ye.O., additional, Kazantzidis, V., additional, Keeling, D.L., additional, Kelly, R., additional, Kempenaars, M., additional, Kennedy, C., additional, Kennedy, D., additional, Kent, J., additional, Khan, K., additional, Khilkevich, E., additional, Kiefer, C., additional, Kilpeläinen, J., additional, Kim, C., additional, Kim, Hyun-Tae, additional, Kim, S.H., additional, King, D.B., additional, King, R., additional, Kinna, D., additional, Kiptily, V.G., additional, Kirjasuo, A., additional, Kirov, K.K., additional, Kirschner, A., additional, kiviniemi, T., additional, Kizane, G., additional, Klas, M., additional, Klepper, C., additional, Klix, A., additional, Kneale, G., additional, Knight, M., additional, Knight, P., additional, Knights, R., additional, Knipe, S., additional, Knolker, M., additional, Knott, S., additional, Kocan, M., additional, Köchl, F., additional, Kodeli, I., additional, Kolesnichenko, Y., additional, Kominis, Y., additional, Kong, M., additional, Korovin, V., additional, Kos, B., additional, Kos, D., additional, Koslowski, H.R., additional, Kotschenreuther, M., additional, Koubiti, M., additional, Kowalska-Strzęciwilk, E., additional, Koziol, K., additional, Krasilnikov, A., additional, Krasilnikov, V., additional, Kresina, M., additional, Krieger, K., additional, Krishnan, N., additional, Krivska, A., additional, Kruezi, U., additional, Książek, I., additional, Kukushkin, A.B., additional, Kumpulainen, H., additional, Kurki-Suonio, T., additional, Kurotaki, H., additional, Kwak, S., additional, Kwon, O.J., additional, Laguardia, L., additional, Lagzdina, E., additional, Lahtinen, A., additional, Laing, A., additional, Lam, N., additional, Lambertz, H.T., additional, Lane, B., additional, Lane, C., additional, Neto, E.Lascas, additional, Łaszyńska, E., additional, Lawson, K.D., additional, Lazaros, A., additional, Lazzaro, E., additional, Learoyd, G., additional, Lee, Chanyoung, additional, Lee, S.E., additional, Leerink, S., additional, Leeson, T., additional, Lefebvre, X., additional, Leggate, H.J., additional, Lehmann, J., additional, Lehnen, M., additional, Leichtle, D., additional, Leipold, F., additional, Lengar, I., additional, Lennholm, M., additional, Gutierrez, E. Leon, additional, Lepiavko, B., additional, Leppänen, J., additional, Lerche, E., additional, Lescinskis, A., additional, Lewis, J., additional, Leysen, W., additional, Li, L., additional, Li, Y., additional, Likonen, J., additional, Linsmeier, Ch., additional, Lipschultz, B., additional, Litaudon, X., additional, Litherland-Smith, E., additional, Liu, F., additional, Loarer, T., additional, Loarte, A., additional, Lobel, R., additional, Lomanowski, B., additional, Lomas, P.J., additional, López, J.M., additional, Lorenzini, R., additional, Loreti, S., additional, Losada, U., additional, Loschiavo, V.P., additional, Loughlin, M., additional, Louka, Z., additional, Lovell, J., additional, Lowe, T., additional, Lowry, C., additional, Lubbad, S., additional, Luce, T., additional, Lucock, R., additional, Lukin, A., additional, Luna, C., additional, Luna, E.de la, additional, Lungaroni, M., additional, Lungu, C.P., additional, Lunt, T., additional, Lutsenko, V., additional, Lyons, B., additional, Lyssoivan, A., additional, Machielsen, M., additional, Macusova, E., additional, Mäenpää, R., additional, Maggi, C.F., additional, Maggiora, R., additional, Magness, M., additional, Mahesan, S., additional, Maier, H., additional, Maingi, R., additional, Malinowski, K., additional, Manas, P., additional, Mantica, P., additional, Mantsinen, M.J., additional, Manyer, J., additional, Manzanares, A., additional, Maquet, Ph., additional, Marceca, G., additional, Marcenko, N., additional, Marchetto, C., additional, Marchuk, O., additional, Mariani, A., additional, Mariano, G., additional, Marin, M., additional, Marinelli, M., additional, Markovič, T., additional, Marocco, D., additional, Marot, L., additional, Marsden, S., additional, Marsh, J., additional, Marshall, R., additional, Martellucci, L., additional, Martin, A., additional, Martin, A.J., additional, Martone, R., additional, Maruyama, S., additional, Maslov, M., additional, Masuzaki, S., additional, Matejcik, S., additional, Mattei, M., additional, Matthews, G.F., additional, Matveev, D., additional, Matveeva, E., additional, Mauriya, A., additional, Maviglia, F., additional, Mayer, M., additional, Mayoral, M.-L., additional, Mazzi, S., additional, Mazzotta, C., additional, McAdams, R., additional, McCarthy, P.J., additional, McClements, K.G., additional, McClenaghan, J., additional, McCullen, P., additional, McDonald, D.C., additional, McGuckin, D., additional, McHugh, D., additional, McIntyre, G., additional, McKean, R., additional, McKehon, J., additional, McMillan, B., additional, McNamee, L., additional, McShee, A., additional, Meakins, A., additional, Medley, S., additional, Meekes, C.J., additional, Meghani, K., additional, Meigs, A.G., additional, Meisl, G., additional, Meitner, S., additional, Menmuir, S., additional, Mergia, K., additional, Merriman, S., additional, Mertens, Ph., additional, Meshchaninov, S., additional, Messiaen, A., additional, Michling, R., additional, Middleton, P., additional, Middleton-Gear, D., additional, Mietelski, J., additional, Milanesio, D., additional, Milani, E., additional, Militello, F., additional, Asp, A.Militello, additional, Milnes, J., additional, Milocco, A., additional, Miloshevsky, G., additional, Minghao, C., additional, Minucci, S., additional, Miron, I., additional, Miyamoto, M., additional, Mlynář, J., additional, Moiseenko, V., additional, Monaghan, P., additional, Monakhov, I., additional, Moody, T., additional, Moon, S., additional, Mooney, R., additional, Moradi, S., additional, Morales, J., additional, Morales, R.B., additional, Mordijck, S., additional, Moreira, L., additional, Morgan, L., additional, Moro, F., additional, Morris, J., additional, Morrison, K.-M., additional, Msero, L., additional, Moulton, D., additional, Mrowetz, T., additional, Mundy, T., additional, Muraglia, M., additional, Murari, A., additional, Muraro, A., additional, Muthusonai, N., additional, N’Konga, B., additional, Na, Yong-Su, additional, Nabais, F., additional, Naden, M., additional, Naish, J., additional, Naish, R., additional, Napoli, F., additional, Nardon, E., additional, Naulin, V., additional, Nave, M.F.F., additional, Nedzelskiy, I., additional, Nemtsev, G., additional, Nesenevich, V., additional, Nestoras, I., additional, Neu, R., additional, Neverov, V.S., additional, Ng, S., additional, Nicassio, M., additional, Nielsen, A.H., additional, Nina, D., additional, Nishijima, D., additional, Noble, C., additional, Nobs, C.R., additional, Nocente, M., additional, Nodwell, D., additional, Nordlund, K., additional, Nordman, H., additional, Normanton, R., additional, Noterdaeme, J.M., additional, Nowak, S., additional, Nunn, E., additional, Nyström, H., additional, Oberparleiter, M., additional, Obryk, B., additional, O'Callaghan, J., additional, Odupitan, T., additional, Oliver, H.J.C., additional, Olney, R., additional, O’Mullane, M., additional, Ongena, J., additional, Organ, E., additional, Orsitto, F., additional, Orszagh, J., additional, Osborne, T., additional, Otin, R., additional, Otsuka, T., additional, Owen, A., additional, Oya, Y., additional, Oyaizu, M., additional, Paccagnella, R., additional, Pace, N., additional, Packer, L.W., additional, Paige, S., additional, Pajuste, E., additional, Palade, D., additional, Pamela, S.J.P., additional, Panadero, N., additional, Panontin, E., additional, Papadopoulos, A., additional, Papp, G., additional, Papp, P., additional, Parail, V.V., additional, Pardanaud, C., additional, Parisi, J., additional, Diaz, F.Parra, additional, Parsloe, A., additional, Parsons, M., additional, Parsons, N., additional, Passeri, M., additional, Patel, A., additional, Pau, A., additional, Pautasso, G., additional, Pavlichenko, R., additional, Pavone, A., additional, Pawelec, E., additional, Soldan, C.Paz, additional, Peacock, A., additional, Pearce, M., additional, Peluso, E., additional, Penot, C., additional, Pepperell, K., additional, Pereira, R., additional, Pereira, T., additional, Cippo, E.Perelli, additional, Pereslavtsev, P., additional, Perez von Thun, C., additional, Pericoli, V., additional, Perry, D., additional, Peterka, M., additional, Petersson, P., additional, Petravich, G., additional, Petrella, N., additional, Peyman, M., additional, Pillon, M., additional, Pinches, S., additional, Pintsuk, G., additional, Pires de Sá, W., additional, Pires dos Reis, A., additional, Piron, C., additional, Pionr, L., additional, Pironti, A., additional, Pitts, R., additional, van de Plassche, K.L., additional, Platt, N., additional, Plyusnin, V., additional, Podesta, M., additional, Pokol, G., additional, Poli, F.M., additional, Pompilian, O.G., additional, Popovichev, S., additional, Poradziński, M., additional, Porfiri, M.T., additional, Porkolab, M., additional, Porosnicu, C., additional, Porton, M., additional, Poulipoulis, G., additional, Predebon, I., additional, Prestopino, G., additional, Price, C., additional, Price, D., additional, Price, M., additional, Primetzhofer, D., additional, Prior, P., additional, Provatas, G., additional, Pucella, G., additional, Puglia, P., additional, Purahoo, K., additional, Pusztai, I., additional, Putignano, O., additional, Pütterich, T., additional, Quercia, A., additional, Rachlew, E., additional, Radulescu, G., additional, Radulovic, V., additional, Rainford, M., additional, Raj, P., additional, Ralph, G., additional, Ramogida, G., additional, Rasmussen, D., additional, Rasmussen, J.J., additional, Rattá, G., additional, Ratynskaia, S., additional, Rebai, M., additional, Réfy, D., additional, Reichle, R., additional, Reinke, M., additional, Reiser, D., additional, Reux, C., additional, Reynolds, S., additional, Richiusa, M.L., additional, Richyal, S., additional, Rigamonti, D., additional, Rimini, F.G., additional, Risner, J., additional, Riva, M., additional, Rivero-Rodriguez, J., additional, Roach, C.M., additional, Robins, R., additional, Robinson, S., additional, Robson, D., additional, Rodionov, R., additional, Rodrigues, P., additional, Ramos, M.Rodriguez, additional, Rodriguez-Fernandez, P., additional, Romanelli, F., additional, Romanelli, M., additional, Romanelli, S., additional, Romazanov, J., additional, Rossi, R., additional, Rowe, S., additional, Rowlands, D., additional, Rubel, M., additional, Rubinacci, G., additional, Rubino, G., additional, Ruchko, L., additional, Ruiz, M., additional, Ruiz, J.Ruiz, additional, Ruset, C., additional, Rzadkiewicz, J., additional, Saarelma, S., additional, Safi, E., additional, Sahlberg, A., additional, Salewski, M., additional, Salmi, A., additional, Salmon, R., additional, Salzedas, F., additional, Sanders, I., additional, Sandiford, D., additional, Santos, B., additional, Santucci, A., additional, Särkimäki, K., additional, Sarwar, R., additional, Sarychev, I., additional, Sauter, O., additional, Sauwan, P., additional, Scapin, N., additional, Schluck, F., additional, Schmid, K., additional, Schmuck, S., additional, Schneider, M., additional, Schneider, P.A., additional, Schwörer, D., additional, Scott, G., additional, Scott, M., additional, Scraggs, D., additional, Scully, S., additional, Segato, M., additional, Seo, Jaemin, additional, Sergienko, G., additional, Sertoli, M., additional, Sharapov, S.E., additional, Shaw, A., additional, Sheikh, H., additional, Sheikh, U., additional, Shepherd, A., additional, Shevelev, A., additional, Shigin, P., additional, Shinohara, K., additional, Shiraiwa, S., additional, Shiraki, D., additional, Short, M., additional, Sias, G., additional, Silburn, S.A., additional, Silva, A., additional, Silva, C., additional, Silva, J., additional, Silvagni, D., additional, Simfukwe, D., additional, Simpson, J., additional, Sinclair, D., additional, Sipilä, S.K., additional, Sips, A.C.C., additional, Sirén, P., additional, Sirinelli, A., additional, Sjöstrand, H., additional, Skinner, N., additional, Slater, J., additional, Smith, N., additional, Smith, P., additional, Snell, J., additional, Snoep, G., additional, Snoj, L., additional, Snyder, P., additional, Soare, S., additional, Solano, E.R., additional, Solokha, V., additional, Somers, A., additional, Sommariva, C., additional, Soni, K., additional, Sorokovoy, E., additional, Sos, M., additional, Sousa, J., additional, Sozzi, C., additional, Spagnolo, S., additional, Spelzini, T., additional, Spineanu, F., additional, Spong, D., additional, Sprada, D., additional, Sridhar, S., additional, Srinivasan, C., additional, Stables, G., additional, Staebler, G., additional, Stamatelatos, I., additional, Stancar, Z., additional, Staniec, P., additional, Stankūnas, G., additional, Stead, M., additional, Stefanikova, E., additional, Stephen, A., additional, Stephens, J., additional, Stevenson, P., additional, Stojanov, M., additional, Strand, P., additional, Strauss, H.R., additional, Strikwerda, S., additional, Ström, P., additional, Stuart, C.I., additional, Studholme, W., additional, Subramani, M., additional, Suchkov, E., additional, Sumida, S., additional, Sun, H.J., additional, Susts, T.E., additional, Svensson, J., additional, Svoboda, J., additional, Sweeney, R., additional, Sytnykov, D., additional, Szabolics, T., additional, Szepesi, G., additional, Tabia, B., additional, Tadić, T., additional, Tál, B., additional, Tala, T., additional, Tallargio, A., additional, Tamain, P., additional, Tan, H., additional, Tanaka, K., additional, Tang, W., additional, Tardocchi, M., additional, Taylor, D., additional, Teimane, A.S., additional, Telesca, G., additional, Teplova, N., additional, Teplukhina, A., additional, Terentyev, D., additional, Terra, A., additional, Terranova, D., additional, Terranova, N., additional, Testa, D., additional, Tholerus, E., additional, Thomas, J., additional, Thoren, E., additional, Thorman, A., additional, Tierens, W., additional, Tinguely, R.A., additional, Tipton, A., additional, Todd, H., additional, Tokitani, M., additional, Tolias, P., additional, Tomeš, M., additional, Tookey, A., additional, Torikai, Y., additional, von Toussaint, U., additional, Tsavalas, P., additional, Tskhakaya, D., additional, Turner, I., additional, Turner, M., additional, Turner, M.M., additional, Turnyanskiy, M., additional, Tvalashvili, G., additional, Tyrrell, S., additional, Tyshchenko, M., additional, Uccello, A., additional, Udintsev, V., additional, Urbanczyk, G., additional, Vadgama, A., additional, Valcarcel, D., additional, Valisa, M., additional, Olivares, P.Vallejos, additional, Vallhagen, O., additional, Valovič, M., additional, Van Eester, D., additional, Varje, J., additional, Vartanian, S., additional, Vasilopoulou, T., additional, Vayakis, G., additional, Vecsei, M., additional, Vega, J., additional, Ventre, S., additional, Verdoolaege, G., additional, Verona, C., additional, Rinati, G.Verona, additional, Veshchev, E., additional, Vianello, N., additional, Viezzer, E., additional, Vignitchouk, L., additional, Vila, R., additional, Villari, R., additional, Villone, F., additional, Vincenzi, P., additional, Vinyar, I., additional, Viola, B., additional, Virtanen, A.J., additional, Vitins, A., additional, Vizvary, Z., additional, Vlad, G., additional, Vlad, M., additional, Vondráček, P., additional, Vries, P.de, additional, Wakeling, B., additional, Walkden, N.R., additional, Walker, M., additional, Walker, R., additional, Walsh, M., additional, Wang, E., additional, Wang, N., additional, Warder, S., additional, Warren, R., additional, Waterhouse, J., additional, Watts, C., additional, Wauters, T., additional, Weckmann, A., additional, Maxwell, H.Wedderburn, additional, Weiland, M., additional, Weisen, H., additional, Weiszflog, M., additional, Welch, P., additional, Wendler, N., additional, West, A., additional, Wheatley, M., additional, Wheeler, S., additional, Whitehead, A., additional, Whittaker, D., additional, Widdowson, A., additional, Wiesen, S., additional, Wilkinson, J., additional, Williams, J.C., additional, Willoughby, D., additional, Wilson, I., additional, Wilson, J., additional, Wilson, T., additional, Wischmeier, M., additional, Wise, P., additional, Withenshaw, G., additional, Withycombe, A., additional, Witts, D., additional, Wojcik-Gargula, A., additional, Wolfrum, E., additional, Wood, R., additional, Woodley, C., additional, Woodley, R., additional, Woods, B., additional, Wright, J., additional, Wright, J.C., additional, Xu, T., additional, Yadikin, D., additional, Yajima, M., additional, Yakovenko, Y., additional, Yang, Y., additional, Yanling, W., additional, Yanovskiy, V., additional, Young, I., additional, Young, R., additional, Zabolockis, R.J., additional, Zacks, J., additional, Zagorski, R., additional, Zaitsev, F.S., additional, Zakharov, L., additional, Zarins, A., additional, Fernandez, D. Zarzoso, additional, Zastrow, K.-D., additional, Zayachuk, Y., additional, Zerbini, M., additional, Zhang, W., additional, Zhou, Y., additional, Zlobinski, M., additional, Zocco, A., additional, Zohar, A., additional, Zoita, V., additional, Zoletnik, S., additional, Zotta, V.K., additional, Zoulias, I., additional, Zwingmann, W., additional, and Zychor, I., additional

Published
2022
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10. Synergetic heating of D-NBI ions in the vicinity of the mode conversion layer in H-D plasmas in JET with the ITER like wall.

Author

Ongena J., Kazakov Ye.O., Baranov Y., Hellesen C., Eriksson J., Johnson T., Kiptily V.G., Mantsinen M.J., Nocente M., Bilato R., Cardinali A., Castaldo C., Crombé K., Czarnecka A., Dumont R., Faustin J., Giacomelli L., Goloborodko V., Graves J., Jacquet Ph., Krawczyk N., Lerche E., Meneses L., Nave M.F.F., Patten H., Schneider M., Van Eester D., Weisen H., and Wright J.C.

Subjects
Physics, QC1-999
Abstract

This paper discusses the extension of the ‘three-ion’ species ICRF technique for heating mixture plasmas using fast injected NBI ions as resonant ‘third’ species. In this scenario the ICRF power is absorbed by the fast beam ions in the vicinity of the mode conversion layer where the left-hand polarized RF electric field E+ is strongly enhanced. The ions in the beam velocity distribution that have a Doppler-shifted resonance close to the mode conversion layer efficiently absorb RF power and undergo acceleration. We show first experimental observations of ICRF heating of D-NBI ions in H-D plasmas in JET with the ITER-like wall. In agreement with theoretical predictions and numerical modelling, acceleration of the D-NBI ions in this D-(DNBI)-H scenario is confirmed by several fast-ion measurements. An extension of the heating scheme discussed here is acceleration of T-NBI and D-NBI ions in D-T plasmas, offering the potential to further boost the Q-value in future D-T campaigns in JET.

Published
2017
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11. Fast-ion orbit sensitivity of neutron and gamma-ray diagnostics for one-step fusion reactions.

Author

Järleblad, H., Stagner, L., Salewski, M., Eriksson, J., Nocente, M., Rasmussen, J., Štancar, Ž., Kazakov, Ye.O., Simmendefeldt, B., and JET Contributors

Subjects
NUCLEAR fusion, ORBITS (Astronomy), NEUTRON temperature, NEUTRON spectroscopy, NEUTRON emission
Abstract

Fast ions in the MeV-range can be diagnosed by neutron emission spectroscopy (NES) and gamma-ray spectroscopy (GRS). In this work, we present orbit weight functions for one-step fusion reactions, using NES and GRS diagnostics on perpendicular and oblique lines-of-sight (LOS) at Joint European Torus (JET) as examples. The orbit weight functions allow us to express the sensitivities of the diagnostics in terms of fast-ion (FI) orbits and can be used to swiftly reproduce synthetic signals that have been computed by established codes. For diagnostically relevant neutron energies for the D(D, n)3He reaction, the orbit sensitivities of the NES diagnostics follow a predictable pattern. As the neutron energy of interest increases, the pattern shifts upwards in FI energy. For the GRS diagnostic and the T(p, Îł)4He reaction, the orbit sensitivity is shown to be qualitatively different for red-shifted, blue-shifted and nominal gamma birth energies. Finally, we demonstrate how orbit weight functions can be used to decompose diagnostic signals into the contributions from different orbit types. For a TRANSP simulation of the JET discharge (a three-ion ICRF scenario) considered in this work, the NES signals for both the perpendicular and oblique LOS are shown to originate mostly from co-passing orbits. In addition, a significant fraction of the NES signal for the oblique LOS is shown to originate from stagnation orbits. [ABSTRACT FROM AUTHOR]

Published
2022
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12. Recent key contributions of ICRF heating in support of plasma scenario development and fast ion studies on JET and ASDEX Upgrade

Author

Mantsinen M.J., Bilato R., Bobkov Vl., Challis C., Gallart D., Garcia-Muñoz M., Jacquet P., Kappatou A., Kazakov Ye.O., Kiptily V., Lerche E., Mantica P., Manyer J., Nocente M., Pütterich T., Sauter O., Sertoli M., Tardini G., Taylor D., Van Eester D., Sharapov S., Weiland M., JET Contributors, EUROfusion, MST1 Team, and AUG Team

Subjects
ICRF, Cyclotron Resonance Frequency, Physics::Plasma Physics, JET, Physics::Accelerator Physics, High Energy Physics::Experiment, fast ion studies, ASDEX Upgrade, plasma scenario
Abstract

Recent key contributions of ICRF heating in support of plasma scenario development and fast ion studies on JET and ASDEX Upgrade.

Published
2021

13. Recent applications of 3-ion ICRF schemes on ASDEX Upgrade and JET in support of ITER

Author

Kazakov Ye.O., Bobkov V., Nocente M., Ongena J., Garcia J., Kappatou A., Kiptily V.G., Mantsinen M.J., Ochoukov R., Schneider M., Weisen H., Baranov Y., Baruzzo M., Bierwage A., Bilato R., Chomiczewska A., Coelho R., Craciunescu T., Crombé K., Delabie E., Dreval M., Dumont R., Dumortier P., Durodié F., Eriksson J., Fitzgerald M., Galdon-Quiroga J., Gallart D., Garcia-Munoz M., Giacomelli L., Giroud C., Gonzalez-Martin J., Hakola A., Jacquet P., Johnson T., Keeling D., King D., Kirov K.K., Lamalle P., Lauber P., Lennholm M., Lerche E., Maslov M., Mazzi S., Menmuir S., Monakhov I., Nabais F., Nave M.F.F., Polevoi A.R., Pinches S.D., Plank U., Rigamonti D., Sahlberg A., Salewski M., Schneider P.A., Sharapov S.E., Stancar Z., Thorman A., Valcarcel D., Van Eester D., Van Schoor M., Varje J., Weiland M., Wendler N., Wright J.C., Wukitch S., JET Contributors, ASDEX Upgrade Team, and EUROfusion MST1 Team

Subjects
Physics::Plasma Physics, Physics::Instrumentation and Detectors, 3-ion ICRF, JET, Astrophysics::High Energy Astrophysical Phenomena, ITER, Physics::Accelerator Physics, High Energy Physics::Experiment, ASDEX Upgrade
Abstract

Recent applications of 3-ion ICRF schemes on ASDEX Upgrade and JET in support of ITER.

Published
2021

14. Impact of suprathermal ions on neutron yield in the pre-DT phase of ITER operation

Author

Polevoi, A.R., primary, Loarte, A., additional, Bilato, R., additional, Gorelenkov, N., additional, Kazakov, Ye.O., additional, Polunovskiy, E., additional, Tchistiakov, A., additional, Fable, E., additional, Kiptily, V., additional, Krasilnikov, A.V., additional, Kuyanov, A.Y., additional, Nazikian, R., additional, Pinches, S.D., additional, and Schneider, M., additional

Published
2021
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15. A novel measurement of marginal Alfvén eigenmode stability during high power auxiliary heating in JET.

Author

Tinguely, R.A., Fil, N., Puglia, P.G., Dowson, S., Porkolab, M., Guillemot, V., PodestĂ, M., Baruzzo, M., Dumont, R., Fasoli, A., Fitzgerald, M., Kazakov, Ye.O., Nave, M.F.F., Nocente, M., Ongena, J., Sharapov, S.E., Ĺ tancar, Ĺ˝., and JET Contributors

Subjects
PLASMA beam injection heating, CYCLOTRON resonance, LANDAU damping, NEUTRAL beams, PLASMA flow
Abstract

The interaction of AlfvĂ©n eigenmodes (AEs) and energetic particles is one of many important factors determining the success of future tokamaks. In JET, eight in-vessel antennas were installed to actively probe stable AEs with frequencies ranging 25â€"250 kHz and toroidal mode numbers | n | < 20. During the 2019â€"2020 deuterium campaign, almost 7500 resonances and their frequencies f 0, net damping rates Îł < 0, and toroidal mode numbers were measured in almost 800 plasma discharges. From a statistical analysis of this database, continuum and radiative damping are inferred to increase with edge safety factor, edge magnetic shear, and when including non-ideal effects. Both stable AE observations and their associated damping rates are found to decrease with | n |. Active antenna excitation is also found to be ineffective in H-mode as opposed to L-mode; this is likely due to the increased edge density gradient’s effect on accessibility and ELM-related noise’s impact on mode identification. A novel measurement is reported of a marginally stable, edge-localized ellipticity-induced AE probed by the antennas during high-power auxiliary heating (ion cyclotron resonance heating and neutral beam injection) up to 25 MW. NOVA-K kinetic-MHD simulations show good agreement with experimental measurements of f 0, Îł, and n, indicating the dominance of continuum and electron Landau damping in this case. Similar experimental and computational studies are planned for the recent hydrogen and ongoing tritium campaigns, in preparation for the upcoming DT campaign. [ABSTRACT FROM AUTHOR]

Published
2022
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17. Validation of realistic Monte Carlo plasma gamma-ray source on JET discharges.

Author

Žohar, A., Nocente, M., Kos, B., Štancar, Ž., Rebai, M., Rigamonti, D., Craciunescu, T., Gorelenkova, M., Kazakov, Ye.O., Kiptily, V.G., Snoj, L., Tardocchi, M., Lengar, I., and JET Contributors

Subjects
PLASMA sources, PLASMA physics, HIGH-frequency discharges, JETS (Nuclear physics), ABSOLUTE value, NEUTRON transport theory
Abstract

A novel modelling methodology has been developed for the creation of a realistic plasma gamma-ray source for Monte Carlo transport simulations in the tokamak JET. The methodology couples the TRANSP code for plasma transport calculations with the MCNP Monte Carlo particle transport code, thus connecting plasma physics with gamma-ray transport. This paper presents the validation of the developed source methodology by comparing calculated gamma-ray spectra with measurements performed at JET. The validation focuses on gamma-ray spectra measured by the tangential gamma-ray spectrometer during two JET three ion RF scenario discharges, performed in the JET 2019 deuterium experimental campaign. For validation the calculated plasma gamma-ray spectrum was combined with the neutron induced prompt gamma-ray background, originating in the vacuum vessel, and scaled to absolute values calculating the total number of plasma gamma-ray and neutron emitting reactions. The comparison between calculated and measured gamma-ray spectra shows good agreement with the shape of the calculated gamma-ray spectra matching that of measurements for both studied discharges. Moreover, the calculated absolute values of the gamma-ray spectra were of the same order of magnitude at the position of the gamma-ray detector located at the end of a long line-of-sight in a biological shield. The comparison has validated the developed plasma gamma-ray source methodology for MCNP photon transport calculations at JET. The validation provides a basis for the developed plasma gamma-ray source to be used as a support for the development of future tokamaks such as DEMO. [ABSTRACT FROM AUTHOR]

Published
2022
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18. AlfvĂ©n cascade eigenmodes above the TAE-frequency and localization of AlfvĂ©n modes in Dâ€" 3 He plasmas on JET.

Author

Dreval, M., Sharapov, S.E., Kazakov, Ye.O., Ongena, J., Nocente, M., Calado, R., Coelho, R., Ferreira, J., Figueiredo, A., Fitzgerald, M., Garcia, J., Giroud, C., Hawkes, N.C., Kiptily, V.G., Nabais, F., Nave, M.F.F., Weisen, H., Craciunescu, T., Salewski, M., and Ĺ tancar, Ĺ˝.

Subjects
PLASMA jets, FAST ions, FUSION reactors, SOFT X rays, TOROIDAL plasma, SAFETY factor in engineering
Abstract

Various types of AlfvĂ©n eigenmodes (AEs) have been destabilized by fast ions over a broad frequency range from ∼80 kHz to ∼700 kHz in a series of JET experiments in mixed Dâ€"3He plasmas heated with the three-ion ICRF scenario (2020 Nocente et al Nucl. Fusion 60 124006). In this paper, we identify the radial localization of AEs using an X-mode reflectometer, a multiline interferometer and soft x-ray diagnostics. The analysis is focused on the most representative example of these measurements in JET pulse #95691, where two different types of AlfvĂ©n cascade (AC) eigenmodes were observed. These modes originate from the presence of a local minimum of the safety factor q min. In addition to ACs with frequencies below the frequency of toroidal AlfvĂ©n eigenmodes (TAEs), ACs with frequencies above the TAE frequency were destabilized by energetic ions. Both low- (f ≈ 80â€"180 kHz) and high-frequency (f ≈ 330â€"450 kHz) ACs were localized in the central regions of the plasma. The characteristics of the high-frequency ACs are investigated in detail numerically using HELENA, CSCAS and MISHKA codes. The resonant conditions for the mode excitation are found to be determined by passing ions of rather high energy of several hundred keV and similar to those established in JT-60U with negative-ion-based NBI (2005 Takechi et al Phys. Plasmas 12 082509). The computed radial mode structure is found to be consistent with the experimental measurements. In contrast to low-frequency ACs observed most often, the frequency of the high-frequency ACs decreases with time as the value of q min decreases. This feature is in a qualitative agreement with the analytical model of the high-frequency ACs in Breizman et al (2003 Phys. Plasmas 10 3649). The high-frequency AC could be highly relevant for future ITER and fusion reactor plasmas dominated by ∼MeV energetic ions, including a significant population of passing fast ions. [ABSTRACT FROM AUTHOR]

Published
2022
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19. Generation and observation of fast deuterium ions and fusion-born alpha particles in JET $\mathrm{D-^3He}$ plasmas with the 3-ion radio-frequency heating scenario

Author

Nocente, M., primary, Kazakov, Ye.O., additional, Garcia, J., additional, Kiptily, V.G., additional, Ongena, J., additional, Dreval, M., additional, Fitzgerald, M., additional, Sharapov, S.E., additional, Stancar, Z., additional, Weisen, H., additional, Baranov, Y., additional, Bierwage, A., additional, Craciunescu, T., additional, Dal Molin, A., additional, de la Luna, E., additional, Dumont, R., additional, Dumortier, P., additional, Eriksson, J., additional, Giacomelli, L., additional, Giroud, C., additional, Goloborodko, V., additional, Gorini, G., additional, Khilkevitch, E., additional, Kirov, K.K., additional, Iliasova, M., additional, Jacquet, P., additional, Lauber, P., additional, Lerche, E., additional, Mantsinen, M.J., additional, Mariani, A., additional, Mazzi, S., additional, Nabais, F., additional, Nave, M.F.F., additional, Oliver, J., additional, Panontin, E., additional, Rigamonti, D., additional, Sahlberg, A., additional, Salewski, M., additional, Shevelev, A., additional, Shinohara, K., additional, Siren, P., additional, Sumida, S., additional, Tardocchi, M., additional, Van Eester, D., additional, Varje, J., additional, Zohar, A., additional, and Contributors, JET, additional

Published
2020
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20. High frequency Alfvén eigenmodes detected with ion-cyclotron-emission diagnostics during NBI and ICRF heated plasmas on the ASDEX Upgrade tokamak

Author

Ochoukov, R., primary, Bilato, R., additional, Bobkov, V., additional, Chapman, S.C., additional, Dendy, R., additional, Dreval, M., additional, Faugel, H., additional, Kappatou, A., additional, Kazakov, Ye.O., additional, Mantsinen, M., additional, McClements, K.G., additional, Moseev, D., additional, Nielsen, S.K., additional, Noterdaeme, J.M., additional, Salewski, M., additional, Schneider, P., additional, and Weiland, M., additional

Published
2020
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21. The ICRH system for the stellarator Wendelstein 7-X

Author

Ongena, J., primary, Messiaen, A., additional, Kazakov, Ye.O., additional, Schweer, B., additional, Stepanov, I., additional, Vervier, M., additional, Crombé, K., additional, Schoor, M. Van, additional, Borsuk, V., additional, Castaño-Bardawil, D., additional, Kraemer-Flecken, A., additional, Hollfeld, K. P., additional, Offermanns, G., additional, Hartmann, D. A., additional, Kallmeyer, J. P., additional, and Wolf, R. C., additional

Published
2020
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22. Spatially resolved measurements of RF accelerated deuterons at JET.

Author

Sahlberg, A., Eriksson, J., Conroy, S., Ericsson, G., Nocente, M., Kazakov, Ye.O., and Contributors, JET

Subjects
LIQUID scintillators, FAST ions, DEUTERONS, NEUTRON counters, PLASMA sheaths, GAUSSIAN distribution, ENERGY density
Abstract

An understanding of fast (supra-thermal) ion behavior is of great importance in tokamak physics and is a subject studied from both theoretical and experimental perspectives. This paper investigates the spatial energy and density distributions of RF accelerated deuterons using the neutron camera at the tokamak JET. Using the 19 liquid scintillator detectors available in the neutron camera system, we obtain spatial information that cannot be accessed with a single sightline. We present a spectroscopic analysis method in which a spatially resolved model of the fast ion distribution is fitted to the pulse height spectra from all 19 detectors simultaneously. The fast ion distribution is parameterized in such a way that the density, energy, and pitch-angle parts are uncoupled. The energy part is composed of a Maxwellian distribution, characterized by an 'RF tail temperature,' and the spatial dependence is modeled as a two-dimensional Gaussian distribution on the poloidal plane of the tokamak. From this parameterized model, we can calculate the spectrum of fusion born neutrons originating from reactions involving RF accelerated deuterons, and by fitting this model to the measured neutron camera pulse height spectra, we obtain an estimate of the spatially resolved distribution of the fast deuterons. The method has been applied to three JET pulses using different RF heating schemes and is shown to identify several features of the fast ion distribution produced in the various scenarios. Hence, this method is able to provide quantitative information about the fast ion distribution resulting from different heating schemes, and can also be useful, e.g., to validate simulation results from RF modeling codes. [ABSTRACT FROM AUTHOR]

Published
2021
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23. Generation and observation of fast deuterium ions and fusion-born alpha particles in JET plasmas with the 3-ion radio-frequency heating scenario.

Author

Nocente, M., Kazakov, Ye.O., Garcia, J., Kiptily, V.G., Ongena, J., Dreval, M., Fitzgerald, M., Sharapov, S.E., Stancar, Z., Weisen, H., Baranov, Y., Bierwage, A., Craciunescu, T., Molin, A. Dal, de la Luna, E., Dumont, R., Dumortier, P., Eriksson, J., Giacomelli, L., and Giroud, C.

Subjects
*DEUTERIUM ions, *PLASMA jets, *FAST ions, *PLASMA beam injection heating, *TRITIUM, *CYCLOTRON resonance, *ALPHA rays, *ION energy
Abstract

Dedicated experiments to generate energetic D ions and fusion-born alpha particles were performed at the Joint European Torus (JET) with the ITER-like wall (ILW). Using the 3-ion radio frequency (RF) heating scenario, deuterium ions from neutral beam injection (NBI) were accelerated in the core of mixed plasmas to higher energies with ion cyclotron resonance frequency (ICRF) waves, in turn leading to a core-localized source of alpha particles. The fast-ion distribution of RF-accelerated D-NBI ions was controlled by varying the ICRF and NBI power (4–6 MW, 3–20 MW), resulting in rather high D-D neutron (≈ 1 × 1016 s−1) and alpha rates (≈ 2 × 1016 s−1) at moderate input heating power. Theory and TRANSP analysis shows that large populations of co-passing MeV-range D ions were generated using the 3-ion ICRF scenario. This important result is corroborated by several experimental observations, in particular gamma-ray measurements. The developed experimental scenario at JET provides unique conditions for probing several aspects of future burning plasmas, such as the contribution from MeV range ions to global confinement, but without introducing tritium. Dominant fast-ion core electron heating with and a rich variety of fast-ion driven Alfvén eigenmodes (AEs) were observed in these plasmas. The observed AE activities do not have a detrimental effect on the thermal confinement and, in some cases, may be driven by the fusion born alpha particles. A strong continuous increase in neutron rate was observed during long-period sawteeth (1 s), accompanied by the observation of reversed shear AEs, which implies that a non monotonic q profile was systematically developed in these plasmas, sustained by the large fast-ion populations generated by the 3-ion ICRF scenario. [ABSTRACT FROM AUTHOR]

Published
2020
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24. Plasma heating and generation of energetic D ions with the 3-ion ICRF + NBI scenario in mixed H-D plasmas at JET-ILW.

Author

Kazakov, Ye.O., Nocente, M., Mantsinen, M.J., Ongena, J., Baranov, Y., Craciunescu, T., Dreval, M., Dumont, R., Eriksson, J., Garcia, J., Giacomelli, L., Kiptily, V.G., Kirov, K.K., Meneses, L., Nabais, F., Nave, M.F.F., Salewski, M., Sharapov, S.E., Štancar, Ž., and Varje, J.

Subjects
*PLASMA heating, *PLASMA production, *PLASMA jets, *FAST ions, *ANDERSON localization
Abstract

Dedicated experiments were conducted in mixed H-D plasmas in JET to demonstrate the efficiency of the 3-ion ICRF scenario for plasma heating, relying on injected fast NBI ions as the resonant ion component. Strong core localization of the RF power deposition in the close vicinity of the ion-ion hybrid layer was achieved, resulting in an efficient plasma heating, generation of energetic D ions, strong enhancement of the neutron rate and observation of Alfvénic modes. A consistent physical picture that emerged from a range of fast-ion measurements at JET, including neutron and gamma-ray measurements, a high-energy neutral particle analyzer and MHD mode localization analysis, is presented. The possibility to moderate the fast-ion energies with the ratio PICRF/PNBI and the choice of the NBI injectors is demonstrated. An outlook of possible applications of the 3-ion scenarios, including a recent example of its use in mixed D-3He plasmas in JET and promising scenarios for D-T plasmas, are presented. [ABSTRACT FROM AUTHOR]

Published
2020
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25. Overview of W7-X ECRH Results.

Author

Poli, E., Laqua, H., Oosterbeek, J., Laqua, H.P., Baldzuhn, J., Braune, H., Bozhenkov, S., Brunner, K.J., Kazakov, Ye.O., Marsen, S., Moseev, D., Stange, T., Wolf, R.C., and Zanini, M.

Subjects
REACTOR charging machines, POLARIZATION (Electricity), STELLARATORS, STEADY state conduction, FUSION reactor divertors
Abstract

In its second operation phase (OP1.2a) W7-X was equipped with full 3d island divertor and an upgraded ECRH-system of 10 gyrotrons with a total port through power of 7 MW. The combination of pellet fueling and high density ECRH enabled to explore density above 1 1020 m-3. In particular with the O2-polarisation combined with a multi-pass reflector tile system a density of up to 1.4 1020 m-3 was achieved. At slightly lower densities high core beta values and record values of the fusion tripple product of 0.66 1020 m-3 keVs for stellarators were reached. In addition routine plasma start-up and ECRH wall conditioning were performed. The island divertor enables to demonstrate the intrinsic steady state capabilities of W7-X, where stationary discharges of up to 30s were demonstrated being only limited by the heat capacity of the uncooled divertor. With the flexible ECRH launch system current density profile variations were used for MHD stability investigations. Here by fine-tuning of the ECCD profile different MHD activity could be triggered. [ABSTRACT FROM AUTHOR]

Published
2019
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26. Efficient generation of energetic ions in multi-ion plasmas by radio-frequency heating

Author

Barcelona Supercomputing Center, Kazakov, Ye.O., Ongena, J., Wright, S.J., Wukith, S.J., Lerche, E., Mantisen, Mervi, van Eester, D., Craciunescu, T., Kiptily, V.G., Lin, Y., Nocente, M., Nabais, F., Nave, M.F.F., Baranov, Y., Bielecki, J., Bilato, R., Bobkov, V., Crombé, K., Czarnecka, A., Faustin, J., Felton, R., Fitzgerald, M., Gallart, Daniel, Giacomelli, L., Golfinopoulos, T., Hubbard, A., Jacquet, Ph., Johnson, T., Lennholm, M., Loarer, T., Porkolab, M., Sharapov, S., Valcarcel, D., van Schoor, M., Weisen, H., JET Contributors, Alcator C-Mod Team, Barcelona Supercomputing Center, Kazakov, Ye.O., Ongena, J., Wright, S.J., Wukith, S.J., Lerche, E., Mantisen, Mervi, van Eester, D., Craciunescu, T., Kiptily, V.G., Lin, Y., Nocente, M., Nabais, F., Nave, M.F.F., Baranov, Y., Bielecki, J., Bilato, R., Bobkov, V., Crombé, K., Czarnecka, A., Faustin, J., Felton, R., Fitzgerald, M., Gallart, Daniel, Giacomelli, L., Golfinopoulos, T., Hubbard, A., Jacquet, Ph., Johnson, T., Lennholm, M., Loarer, T., Porkolab, M., Sharapov, S., Valcarcel, D., van Schoor, M., Weisen, H., JET Contributors, and Alcator C-Mod Team

Abstract

We describe a new technique for the efficient generation of high-energy ions with electromagnetic ion cyclotron waves in multi-ion plasmas. The discussed ‘three-ion’ scenarios are especially suited for strong wave absorption by a very low number of resonant ions. To observe this effect, the plasma composition has to be properly adjusted, as prescribed by theory. We demonstrate the potential of the method on the world-largest plasma magnetic confinement device, JET (Joint European Torus, Culham, UK), and the high-magnetic-field tokamak Alcator C-Mod (Cambridge, USA). The obtained results demonstrate efficient acceleration of 3He ions to high energies in dedicated hydrogen–deuterium mixtures. Simultaneously, effective plasma heating is observed, as a result of the slowing-down of the fast 3He ions. The developed technique is not only limited to laboratory plasmas, but can also be applied to explain observations of energetic ions in space-plasma environments, in particular, 3He-rich solar flares., This paper is dedicated to the late P. E. M. Vandenplas, founder and first director of LPP-ERM/KMS, in recognition of his lifelong outstanding commitment to fusion research, in particular to ICRH. The support from the JET and Alcator C-Mod Teams is warmly acknowledged. We are grateful to A. Cardinali, C. Castaldo, R. Dumont, J. Eriksson, T. Fülöp, C. Giroud, C. Hellesen, S. Menmuir and M. Schneider for fruitful discussions. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 under grant agreement no. 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. This work was also supported by the US DoE, Office of Science, Office of Fusion Energy Sciences, SciDAC Center for Simulation of Wave Plasma Interactions under DE-FC02-01ER54648 and the User Facility Alcator C-Mod under DE-FC02-99ER54512. The Alcator C-Mod Team author list is reproduced from ref. 12. The JET Contributors author list is reproduced from ref. 33., Peer Reviewed, Postprint (author's final draft)

Published
2017

28. Technological and physics assessments on heating and current drive systems for DEMO

Author

Franke, Thomas, primary, Barbato, E., additional, Bosia, G., additional, Cardinali, A., additional, Ceccuzzi, S., additional, Cesario, R., additional, Van Eester, D., additional, Federici, G., additional, Gantenbein, G., additional, Helou, W., additional, Hillairet, J., additional, Jenkins, I., additional, Kazakov, Ye.O., additional, Kemp, R., additional, Lerche, E., additional, Mirizzi, F., additional, Noterdaeme, J.-M., additional, Poli, E., additional, Porte, L., additional, Ravera, G.L., additional, Surrey, E., additional, Tardini, G., additional, Tran, M.Q., additional, Tsironis, C., additional, Tuccillo, A.A., additional, Wenninger, R., additional, and Zohm, H., additional

Published
2015
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30. ICRF heating of hydrogen plasmas with two mode conversion layers

Author

Kazakov, Ye.O., Van Eester, D., Lerche, E., Pavlenko, I.V., Girka, I.O., and Weyssow, B.

Subjects
Методы создания и нагрева плазмы
Abstract

ICRF mode conversion heating regime is widely used in present-day tokamaks. The theoretically predicted mode conversion enhancement due to the constructive interference of the fast wave reflected from the evanescence layer with a wave reflected from the high-field side cutoff was first experimentally identified in JET in (3He)D experiments. This effect was recently tested in (3He)H plasmas, which is one of the ICRF heating scenarios considered for the non-activated phase of ITER operation. Due to the presence of the intrinsic D-like impurities in JET (e.g., C6+, 4He) the supplementary conversion layer was produced in the plasma that defined the interference conditions. The different behavior of the conversion efficiency observed at various 3He concentrations is analyzed in the paper on the basis of the theory of the fast wave mode conversion in plasmas with two evanescence layers. Высокочастотный нагрев плазмы в режиме конверсии мод широко используется в современных токамаках. Теоретически предсказанное увеличение эффективности конверсии вследствие интерференции быстрой волны, отраженной от области непрозрачности, с волной, отраженной от отсечки со стороны сильного магнитного поля, было впервые экспериментально подтверждено в (3He)D-экспериментах на токамаке JET. Данный эффект изучался в (3He)H-плазме, которая рассматривается как один из сценариев ВЧ-нагрева во время начальной стадии работы ITER. Вследствие присутствия в плазме JET дейтериеподобных примесей (C6+, 4He) образовывалась дополнительная область непрозрачности, которая определяла условия интерференции волн. Различное поведение коэффициента конверсии, наблюдаемое при разных значениях концентрации ионов 3He, анализируется в работе с помощью теории конверсии быстрых волн в плазме с двумя областями непрозрачности. Високочастотне нагрівання плазми в режимі конверсії мод широко застосовується в сучасних токамаках. Теоретично передбачене збільшення ефективності конверсії внаслідок інтерференції швидкої хвилі, що відбита від шару непрозорості, з хвилею, що відбита від відсічки з боку сильного магнітного поля, було вперше експериментально підтверджено в (3He)D-експериментах на токамаці JET. Цей ефект нещодавно апробовано в (3He)H-плазмі, яка розглядається як один із сценаріїв ВЧ-нагрівання на початковій стадії роботи ITER. Внаслідок присутності в плазмі JET дейтерієподібних домішок (C6+, 4He) утворювався додатковий шар непрозорості, що визначав умови інтерференції хвиль. Різна поведінка коефіцієнту конверсії, що спостерігалася за різної концентрації іонів 3He, аналізується в роботі на основі теорії конверсії швидких хвиль в плазмі з двома шарами непрозорості.

Published
2010

31. Fast wave mode conversion in multicomponent nonuniform plasmas

Author

Kazakov, Ye.O., Pavlenko, I.V., Girka, I.O., and Weyssow, B.

Subjects
Plasma heating and current drive
Abstract

The ICRF mode conversion heating scenario relevant to the start-up phase of ITER operation is studied. The 1D theory of fast wave (FW) propagation in fusion plasmas is applied to study the inverted ICRF (³He)H scenario with two ion-ion hybrid resonances for the typical conditions of the tokamak JET. The role of the intrinsic impurity C⁶⁺ ions in the mode conversion for the considered heating scenario is discussed. It is shown that for the modest concentrations of carbon impurity (above ~ 1.5%) the corresponding evanescence layer is enough wide to reflect the FW and produce the interference pattern which, in turn, determines the mode conversion efficiency and subsequent local electron heating. Досліджується сценарій високочастотного нагрівання плазми в режимі конверсії мод, який має відношення до початкової фази роботи токамака ITER. Одновимірна модель поширення швидких магнітозвукових хвиль (ШХ) в плазмі була застосована для вивчення (³He)H сценарія нагрівання з двома іон-іонними гібридними резонансами для типових умов токамака JET. Розглядається вплив іонів домішки вуглецю C⁶ на процес конверсії для даного сценарію нагрівання. Показано, що для помірних значень концентрації вуглецю (більше за ~1.5%) відповідний шар непрозорості є достатньо широким для того, щоб відбити ШХ та створити інтерференційну структуру, яка, в свою чергу, визначає ефективність конверсії та подальшого локального нагрівання електронів. Изучается сценарий высокочастотного нагрева плазмы в режиме конверсии мод, имеющий отношение к начальной стадии работы токамака ITER. Одномерная модель распространения быстрых магнитозвуковых волн (БВ) в плазме была применена для изучения (³He)H сценария нагрева с двумя ион-ионными гибридными резонансами для типичных условий токамака JET. Рассматривается влияние C⁶⁺ ионов примеси на процесс конверсии для данного сценария нагрева. Показано, что для умеренных значений концентрации углерода (больше ~1.5%) соответствующий слой непрозрачности является достаточно широким для того, чтобы отразить БВ и создать интерференционную структуру, которая, в свою очередь, определяет эффективность конверсии и последующего локального нагрева электронов.

Published
2008

32. Fast Alfvén wave propagation in milticomponent nonuniform plasmas

Author

Kazakov, Ye.O., Pavlenko, I.V., Girka, I.O., and Weyssow, B.

Subjects
Термоядерный синтез (коллективные процессы)
Abstract

The problem of the conversion, reflection and transmission of the fast Alfvén wave propagating in multicomponent nonuniform plasmas is studied. The dependences of the wave scattering characteristics on the plasma composition and parallel wave number have been obtained. The results can be used to control the part of the launched power converted to the slow short wavelength mode and to prevent the essential reflection of the wave power back to the antenna. Вивчається задача конверсії, відбиття та проходження швидкої магнітозвукової хвилі, яка поширюється у багатокомпонентній неоднорідній плазмі. Отримано залежності характеристик проходження хвилі від складу плазми та від паралельного хвильового вектора. Отримані результати можуть бути використані для керування частиною енергії хвилі, яка конвертується у короткохвильову моду, та для запобігання суттєвого відбиття енергії хвилі назад до антени. Изучается задача конверсии, отражения и прохождения быстрой магнитозвуковой волны, распространяющейся в многокомпонентной неоднородной плазме. Получены зависимости характеристик прохождения волны от состава плазмы и от параллельного волнового вектора. Полученные результаты могут быть использованы для управления частью энергии волны, которая конвертируется в коротковолновую моду, и для предотвращения существенного отражения энергии волны назад к антенне.

Published
2008

33. Effect of plasma shaping and resonance location on minority ion temperature anisotropy in tokamak plasmas heated with ICRH

Author

Kazakov, Ye.O., Fülöp, T., Pusztai, I., Johnson, Thomas, Kazakov, Ye.O., Fülöp, T., Pusztai, I., and Johnson, Thomas

Abstract

Poloidal asymmetries of the impurity distribution, which are observed in tokamaks, may influence the impurity cross-field transport. Low field side ion cyclotron resonance heating (ICRH) often results in an inboard accumulation of impurities, which may in turn lead to an outward convective impurity flux. The temperature anisotropy of the ICRH-heated minority ions is identified to be one of the main parameters governing the impurity asymmetry strength. In the present work we analyze the effect of plasma shaping and the ICRH resonance location on the minority temperature anisotropy by means of the TORIC-SSFPQL modelling. We find that ellipticity reduces the anisotropy level due to the wave defocussing and broader absorption regions for the elongated plasmas. The temperature anisotropy decrease in case of the resonance layers located closer to the edge is caused by the significant reduction in heating power densities due to geometrical reasons., QC 20130314

Published
2012
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36. The Dedicated ICRH System for the Stellarator Wendelstein 7-X.

Author

Ongena, J., Messiaen, A., Dumortier, P., Durodie, F., Kazakov, Ye.O., Louche, F., Schweer, B., Vervier, M., Van Eester, D., Koch, R., Krivska, A., Lyssoivan, A., Van Schoor, M., Wauters, T., Borsuk, V., Neubauer, O., Schmitz, O., Offermans, G., Altenburg, Y., and Baylard, C.

Subjects
STELLARATORS, ANTENNAS in plasma, PLASMA gases, POWER spectra, MAGNETIC fields, SUPERCONDUCTING coils, PLASMA beam injection heating, ICR heating
Abstract

The current status of the mechanical and electromagnetic design for the ICRF antenna system for W7-X is presented. Two antenna plugins are discussed : one consisting of a pair of straps with pre-matching to cover the first frequency band 25-38 MHz and a second one consisting of two short strap triplets to cover a frequency band around 76 MHz. This paper focusses on the two strap antenna for the lower frequency band. Power coupling of the antenna to a reference plasma profile is studied with the help of the codes TOPICA and Microwave Studio, that deliver the scattering matrix needed for the optimization of the geometric parameters of the straps and antenna box. Radiation power spectra for different phasings of the two straps are obtained using the code ANTITER II and different heating scenarii are discussed. The potential for heating, fast particle generation and current drive is discussed. The problem of RF coupling through the plasma edge and of edge power deposition is summarized. The system contains a prematching capacitor to limit the maximum voltage in the system, and the large mutual coupling between the 2 straps is counterbalanced by the use of a decoupler. The mechanical design highlights the challenges encountered with this antenna : adaptation to a large variety of plasma configurations, the limited space within the port to accommodate the necessary matching components and the watercooling needed for long pulse operation. [ABSTRACT FROM AUTHOR]

Published
2014
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