Isotope physics of heat and particle transport with tritium in JET-ILW type-I ELMy H-mode plasmas

Nuclear Fushion

article

P.A. Schneider¹  C. Angioni¹  F. Auriemma²  N. Bonanomi¹  T. Görler¹  R. Henriques⁴  L. Horvath⁵  D. King⁵  R. Lorenzini²  H. Nyström⁷  M. Maslov⁵  J. Ruiz⁸  G. Szepesi⁵  C.D. Challis⁵  A. Chomiczewska⁹  E. Delabie^1,10  J.M. Fontdecaba^1,11  L. Frassinetti⁷  J. Garcia^1,12  C. Giroud⁵  J. Hillesheim⁵  J. Hobirk¹  A. Kappatou¹  D.L. Keeling⁵  E. Kowalska-Strzeciwilk⁹  M. Lennholm⁵  B. Lomanowski^1,10  T. Luda di Cortemiglia¹  C.F. Maggi⁵  S. Menmuir⁵  G. Pucella^1,13  A. Thorman⁵ 

[1] Max-Planck-Institut für Plasmaphysik;Consorzio RFX-CNR, ENEA, INFN, Università di Padova;CNR-ISTP;Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa;United Kingdom Atomic Energy Authority, Culham Science Centre;Princeton Plasma Physics Laboratory, Princeton;KTH Royal Institute of Technology;Rudolf Peierls Centre for Theoretical Physics, University of Oxford;Institute of Plasma Physics and Laser Microfusion;Oak Ridge National Laboratory;Laboratorio Nacional de Fusión Ciemat;CEA;Dip.to Fusione e Tecnologie per la Sicurezza Nucleare

关键词: H-mode;    tritium;    heat transport;    particle transport;    stability;    isotopes;   

DOI  :  10.1088/1741-4326/acf560

来源: Institute of Physics Publishing Ltd.

【 摘 要 】

As part the DTE2 campaign in the JET tokamak, we conducted a parameter scan in T and D-T complementing existing pulses in H and D. For the different main ion masses, type-I ELMy H-modes at fixed plasma current and magnetic field can have the pedestal pressure varying by a factor of 4 and the total pressure changing from beta_{mathrm{N}} = 1.0to 3.0. We investigated the pedestal and core isotope mass dependencies using this extensive data set. The pedestal shows a strong mass dependence on the density, which influences the core due to the strong coupling between both plasma regions. To better understand the causes for the observed isotope mass dependence in the pedestal, we analysed the interplay between heat and particle transport and the edge localised mode (ELM) stability. For this purpose, we developed a dynamic ELM cycle model with basic transport assumptions and a realistic neutral penetration. The temporal evolution and resulting ELM frequency introduce an additional experimental constraint that conventional quasi-stationary transport analysis cannot provide. Our model shows that a mass dependence in the ELM stability or in the transport alone cannot explain the observations. One requires a mass dependence in the ELM stability as well as one in the particle sources. The core confinement time increases with pedestal pressure for all isotope masses due to profile stiffness and electromagnetic turbulence stabilisation. Interestingly, T and D-T plasmas show an improved core confinement time compared to H and D plasmas even for matched pedestal pressures. For T, this improvement is largely due to the unique pedestal composition of higher densities and lower temperatures than H and D. With a reduced gyroBohm factor at lower temperatures, more turbulent drive in the form of steeper gradients is required to transport the same amount of heat. This picture is supported by quasilinear flux-driven modelling usingTGLF -SAT2 withinAstra . With the experimental boundary conditionTGLF -SAT2 predicts the core profiles well for gyroBohm heat fluxes {gt}15 , however, overestimates the heat and particle transport closer to the turbulent threshold.

【 授权许可】

Unknown