TY - JOUR
T1 - Shear Reversal and Mhd Activity During Pellet Enhanced Performance Pulses in Jet
JF - Nuclear Fusion
Y1 - 1992
A1 - Hugon, M.
A1 - van Milligen, B. P.
A1 - Smeulders, P.
A1 - Appel, L. C.
A1 - Bartlett, D. V.
A1 - Boucher, D.
A1 - Edwards, A. W.
A1 - Eriksson, L. G.
A1 - Gowers, C. W.
A1 - Hender, T. C.
A1 - Huysmans, G.
A1 - Jacquinot, J. J.
A1 - Kupschus, P.
A1 - Porte, L.
A1 - Rebut, P. H.
A1 - Start, D. F. H.
A1 - Tibone, F.
A1 - Tubbing, B. J. D.
A1 - Watkins, M. L.
A1 - Zwingmann, W.
AB - Analysis of MHD activity in Pellet Enhanced Performance (PEP) pulses is used to determine the position of rational surfaces associated with the safety factor q. This gives evidence for negative shear in the central region of the plasma. The plasma equilibrium calculated from the measured q values yields a Shafranov shift in reasonable agreement with the experimental value of about 0.2 m. The corresponding current profile has two large off-axis maxima in agreement with the bootstrap current calculated from the electron temperature and density measurements. A transport simulation shows that the bootstrap current is driven by the steep density gradient, which results from improved confinement in the plasma core where the shear is negative. During the PEP phase, (m, n) = (1, 1) fast MHD events are correlated with collapses in the neutron rate. The dominant mode preceding these events usually is n = 3, whereas the mode following them is dominantly n = 2. Toroidal linear MHD stability calculations assuming a non-monotonic q-profile with an off-axis minimum decreasing from above 1 to below 1 describe this sequence of modes (n = 3, 1, 2), but always give a larger growth rate for the n = 1 mode than for the n = 2 mode. This large growth rate is due to the high central poloidal beta of 1.5 observed in the PEP pulses. Finally, a rotating (m, n) = (1, 1) mode is observed as a hot spot with a ballooning character on the low field side. The hot spot has some of the properties of a 'hot' island consistent with the presence of a region of negative shear.
VL - 32
SN - 0029-5515
U5 - 25a36c4ffccde2efa62d7503c5bdc2a9
ER -
TY - JOUR
T1 - Fusion Energy-Production from a Deuterium-Tritium Plasma in the Jet Tokamak
JF - Nuclear Fusion
Y1 - 1992
A1 - Rebut, P. H.
A1 - Gibson, A.
A1 - Huguet, M.
A1 - Adams, J. M.
A1 - Alper, B.
A1 - Altmann, H.
A1 - Andersen, A.
A1 - Andrew, P.
A1 - Angelone, M.
A1 - Aliarshad, S.
A1 - Baigger, P.
A1 - Bailey, W.
A1 - Balet, B.
A1 - Barabaschi, P.
A1 - Barker, P.
A1 - Barnsley, R.
A1 - Baronian, M.
A1 - Bartlett, D. V.
A1 - Baylor, L.
A1 - Bell, A. C.
A1 - Benali, G.
A1 - Bertoldi, P.
A1 - Bertolini, E.
A1 - Bhatnagar, V.
A1 - Bickley, A. J.
A1 - Binder, D.
A1 - Bindslev, H.
A1 - Bonicelli, T.
A1 - Booth, S. J.
A1 - Bosia, G.
A1 - Botman, M.
A1 - Boucher, D.
A1 - Boucquey, P.
A1 - Breger, P.
A1 - Brelen, H.
A1 - Brinkschulte, H.
A1 - Brooks, D.
A1 - Brown, A.
A1 - Brown, T.
A1 - Brusati, M.
A1 - Bryan, S.
A1 - Brzozowski, J.
A1 - Buchse, R.
A1 - Budd, T.
A1 - Bures, M.
A1 - Businaro, T.
A1 - Butcher, P.
A1 - Buttgereit, H.
A1 - Caldwellnichols, C.
A1 - Campbell, D. J.
A1 - Card, P.
A1 - Celentano, G.
A1 - Challis, C. D.
A1 - Chankin, A. V.
A1 - Cherubini, A.
A1 - Chiron, D.
A1 - Christiansen, J.
A1 - Chuilon, P.
A1 - Claesen, R.
A1 - Clement, S.
A1 - Clipsham, E.
A1 - Coad, J. P.
A1 - Coffey, I. H.
A1 - Colton, A.
A1 - Comiskey, M.
A1 - Conroy, S.
A1 - Cooke, M.
A1 - Cooper, D.
A1 - Cooper, S.
A1 - Cordey, J. G.
A1 - Core, W.
A1 - Corrigan, G.
A1 - Corti, S.
A1 - Costley, A. E.
A1 - Cottrell, G.
A1 - Cox, M.
A1 - Cripwell, P.
A1 - Dacosta, O.
A1 - Davies, J.
A1 - Davies, N.
A1 - de Blank, H.
A1 - De Esch, H.
A1 - Dekock, L.
A1 - Deksnis, E.
A1 - Delvart, F.
A1 - Dennehinnov, G. B.
A1 - Deschamps, G.
A1 - Dickson, W. J.
A1 - Dietz, K. J.
A1 - Dmitrenko, S. L.
A1 - Dmitrieva, M.
A1 - Dobbing, J.
A1 - Doglio, A.
A1 - Dolgetta, N.
A1 - Dorling, S. E.
A1 - Doyle, P. G.
A1 - Duchs, D. F.
A1 - Duquenoy, H.
A1 - Edwards, A.
A1 - Ehrenberg, J.
A1 - Ekedahl, A.
A1 - Elevant, T.
A1 - Erents, S.K.
A1 - Eriksson, L. G.
A1 - Fajemirokun, H.
A1 - Falter, H.
A1 - Freiling, J.
A1 - Freville, F.
A1 - Froger, C.
A1 - Froissard, P.
A1 - Fullard, K.
A1 - Gadeberg, M.
A1 - Galetsas, A.
A1 - Gallagher, T.
A1 - Gambier, D.
A1 - Garribba, M.
A1 - Gaze, P.
A1 - Giannella, R.
A1 - Gill, R. D.
A1 - Girard, A.
A1 - Gondhalekar, A.
A1 - Goodall, D.
A1 - Gormezano, C.
A1 - Gottardi, N. A.
A1 - Gowers, C.
A1 - Green, B. J.
A1 - Grievson, B.
A1 - Haange, R.
A1 - Haigh, A.
A1 - Hancock, C. J.
A1 - Harbour, P. J.
A1 - Hartrampf, T.
A1 - Hawkes, N. C.
A1 - Haynes, P.
A1 - Hemmerich, J. L.
A1 - Hender, T.
A1 - Hoekzema, J.
A1 - Holland, D.
A1 - Hone, M.
A1 - Horton, L.
A1 - How, J.
A1 - Huart, M.
A1 - Hughes, I.
A1 - Hughes, T. P.
A1 - Hugon, M.
A1 - Huo, Y.
A1 - Ida, K.
A1 - Ingram, B.
A1 - Irving, M.
A1 - Jacquinot, J.
A1 - Jaeckel, H.
A1 - Jaeger, J. F.
A1 - Janeschitz, G.
A1 - Jankovicz, Z.
A1 - Jarvis, O. N.
A1 - Jensen, F.
A1 - Jones, E. M.
A1 - Jones, H. D.
A1 - Jones, Lpdf
A1 - Jones, S.
A1 - Jones, T. T. C.
A1 - Junger, J. F.
A1 - Junique, F.
A1 - Kaye, A.
A1 - Keen, B. E.
A1 - Keilhacker, M.
A1 - Kelly, G. J.
A1 - Kerner, W.
A1 - Khudoleev, A.
A1 - Konig, R.
A1 - Konstantellos, A.
A1 - Kovanen, M.
A1 - Kramer, G.
A1 - Kupschus, P.
A1 - Lasser, R.
A1 - Last, J. R.
A1 - Laundy, B.
A1 - Laurotaroni, L.
A1 - Laveyry, M.
A1 - Lawson, K.
A1 - Lennholm, M.
A1 - Lingertat, J.
A1 - Litunovski, R. N.
A1 - Loarte, A.
A1 - Lobel, R.
A1 - Lomas, P.
A1 - Loughlin, M.
A1 - Lowry, C.
A1 - Lupo, J.
A1 - Maas, A. C.
A1 - Machuzak, J.
A1 - Macklin, B.
A1 - Maddison, G.
A1 - Maggi, C. F.
A1 - Magyar, G.
A1 - Mandl, W.
A1 - Marchese, V.
A1 - Marcon, G.
A1 - Marcus, F.
A1 - Mart, J.
A1 - Martin, D.
A1 - Martin, E.
A1 - Martinsolis, R.
A1 - Massmann, P.
A1 - Matthews, G.
A1 - McBryan, H.
A1 - McCracken, G.
A1 - McKivitt, J.
A1 - Meriguet, P.
A1 - Miele, P.
A1 - Miller, A.
A1 - Mills, J.
A1 - Mills, S. F.
A1 - Millward, P.
A1 - Milverton, P.
A1 - Minardi, E.
A1 - Mohanti, R.
A1 - Mondino, P. L.
A1 - Montgomery, D.
A1 - Montvai, A.
A1 - Morgan, P.
A1 - Morsi, H.
A1 - Muir, D.
A1 - Murphy, G.
A1 - Myrnas, R.
A1 - Nave, F.
A1 - Newbert, G.
A1 - Newman, M.
A1 - Nielsen, P.
A1 - Noll, P.
A1 - Obert, W.
A1 - Obrien, D.
A1 - Orchard, J.
A1 - Orourke, J.
A1 - Ostrom, R.
A1 - Ottaviani, M.
A1 - Pain, M.
A1 - Paoletti, F.
A1 - Papastergiou, S.
A1 - Parsons, W.
A1 - Pasini, D.
A1 - Patel, D.
A1 - Peacock, A.
A1 - Peacock, N.
A1 - Pearce, R. J. M.
A1 - Pearson, D.
A1 - Peng, J. F.
A1 - Desilva, R. P.
A1 - Perinic, G.
A1 - Perry, C.
A1 - Petrov, M.
A1 - Pick, M. A.
A1 - Plancoulaine, J.
A1 - Poffe, J. P.
A1 - Pohlchen, R.
A1 - Porcelli, F.
A1 - Porte, L.
A1 - Prentice, R.
A1 - Puppin, S.
A1 - Putvinskii, S.
A1 - Radford, G.
A1 - Raimondi, T.
A1 - Deandrade, M. C. R.
A1 - Reichle, R.
A1 - Reid, J.
A1 - Richards, S.
A1 - Righi, E.
A1 - Rimini, F.
A1 - Robinson, D.
A1 - Rolfe, A.
A1 - Ross, R. T.
A1 - Rossi, L.
A1 - Russ, R.
A1 - Rutter, P.
A1 - Sack, H. C.
A1 - Sadler, G.
A1 - Saibene, G.
A1 - Salanave, J. L.
A1 - Sanazzaro, G.
A1 - Santagiustina, A.
A1 - Sartori, R.
A1 - Sborchia, C.
A1 - Schild, P.
A1 - Schmid, M.
A1 - Schmidt, G.
A1 - Schunke, B.
A1 - Scott, S. M.
A1 - Serio, L.
A1 - Sibley, A.
A1 - Simonini, R.
A1 - Sips, A.C.C.
A1 - Smeulders, P.
A1 - Smith, R.
A1 - Stagg, R.
A1 - Stamp, M.
A1 - Stangeby, P.
A1 - Stankiewicz, R.
A1 - Start, D. F.
A1 - Steed, C. A.
A1 - Stork, D.
A1 - Stott, P.E.
A1 - Stubberfield, P.
A1 - Summers, D.
A1 - Summers, H.
A1 - Svensson, L.
A1 - Tagle, J. A.
A1 - Talbot, M.
A1 - Tanga, A.
A1 - Taroni, A.
A1 - Terella, C.
A1 - Terrington, A.
A1 - Tesini, A.
A1 - Thomas, P. R.
A1 - Thompson, E.
A1 - Thomsen, K.
A1 - Tibone, F.
A1 - Tiscornia, A.
A1 - Trevalion, P.
A1 - Tubbing, B.
A1 - Vanbelle, P.
A1 - Vanderbeken, H.
A1 - Vlases, G.
A1 - von Hellermann, M.
A1 - Wade, T.
A1 - Walker, C.
A1 - Walton, R.
A1 - Ward, D.
A1 - Watkins, M. L.
A1 - Watkins, N.
A1 - Watson, M. J.
A1 - Weber, S.
A1 - Wesson, J.
A1 - Wijnands, T. J.
A1 - Wilks, J.
A1 - Wilson, D.
A1 - Winkel, T.
A1 - Wolf, R.
A1 - Wong, D.
A1 - Woodward, C.
A1 - Wu, Y.
A1 - Wykes, M.
A1 - Young, D.
A1 - Young, I. D.
A1 - Zannelli, L.
A1 - Zolfaghari, A.
A1 - Zwingmann, W.
AB - The paper describes a series of experiments in the Joint European Torus (JET), culminating in the first tokamak discharges in deuterium-tritium fuelled mixtures. The experiments were undertaken within limits imposed by restrictions on vessel activation and tritium usage. The objectives were: (i) to produce more than one megawatt of fusion power in a controlled way; (ii) to validate transport codes and provide a basis for accurately predicting the performance of deuterium-tritium plasma from measurements made in deuterium plasmas; (iii) to determine tritium retention in the torus systems and to establish the effectiveness of discharge cleaning techniques for tritium removal; (iv) to demonstrate the technology related to tritium usage; and (v) to establish safe procedures for handling tritium in compliance with the regulatory requirements. A single-null X-point magnetic configuration, diverted onto the upper carbon target, with reversed toroidal magnetic field was chosen. Deuterium plasmas were heated by high power, long duration deuterium neutral beams from fourteen sources and fuelled also by up to two neutral beam sources injecting tritium. The results from three of these high performance hot ion H-mode discharges are described: a high performance pure deuterium discharge; a deuterium-tritium discharge with a 1% mixture of tritium fed to one neutral beam source; and a deuterium-tritium discharge with 100% tritium fed to two neutral beam sources. The TRANSP code was used to check the internal consistency of the measured data and to determine the origin of the measured neutron fluxes. In the best deuterium-tritium discharge, the tritium concentration was about 11% at the time of peak performance, when the total neutron emission rate was 6.0 x 10(17) neutrons/s. The integrated total neutron yield over the high power phase, which lasted about 2 s, was 7.2 x 10(17) neutrons, with an accuracy of +/- 7%. The actual fusion amplification factor, Q(DT), was about 0.15. With an optimum tritium concentration, this pulse would have produced a fusion power of almost-equal-to 5 MW and a nominal Q(DT) almost-equal-to 0.46. The same extrapolation for the pure deuterium discharge would have given almost-equal-to 11 MW and a nominal Q(DT) = 1.14, so that the total fusion power (neutrons and alpha-particles) would have exceeded the total losses in the equivalent deuterium-tritium discharge in these transient conditions. Techniques for introducing, tracking, monitoring and recovering tritium were demonstrated to be highly effective: essentially all of the tritium introduced into the neutral beam system and, so far, about two thirds of that introduced into the torus have been recovered.
VL - 32
SN - 0029-5515
U5 - e65831798ed0c55ed964fef6ea71d10c
ER -