Plasma density behavior with new graphite limiters in the Hefei Tokamak-7

Asif, M.; Gao, X.; Li, J.; Kuang, G. L.; Wan, B. N.; Jie, Y. X.; Zhao, J. Y.; Zhang, X. D.; Liu, H. Q.; Tong, X. D.; Liu, J.; Xu, Q.; Hu, J. S.; Yang, Y.; Shen, B.; Mao, J. S.; Hu, L. Q.; Wu, Z. W.; Ling, B. L.
August 2005
Physics of Plasmas;Aug2005, Vol. 12 Issue 8, p082502
Academic Journal
A new set of actively cooled toroidal double-ring graphite limiters has been developed in the Hefei Tokamak-7 (HT-7) [X. Gao et al., Phys. Plasmas 7, 2933 (2000)] for long pulse operation. The extension of operational region and density behavior with graphite (C) limiters have been studied in this paper. Extended high-density region at the high plasma current low-qa was obtained. The density profile with the C limiter was studied to compare with the previous molybdenum (Mo) limiter. The critical density of multifaceted asymmetric radiation from the edge (MARFE) onset is observed in the region of Zeff½fGW=0.9∼1.2, where fGW=ne/nGW. (Here ne is the maximum line average electron density and nGW is the Greenwald density.) Under the same injected power, the critical density of MARFE onset with the new C limiter is much higher than the previous Mo limiter.


Related Articles

  • Active control of internal transport barrier formation due to off-axis electron-cyclotron heating in GAMMA 10 experiments. Cho, T.; Pastukhov, V. P.; Horton, W.; Numakura, T.; Hirata, M.; Kohagura, J.; Chudin, N. V.; Pratt, J. // Physics of Plasmas;May2008, Vol. 15 Issue 5, p056120 

    The controlled formation of an internal transport barrier (ITB) is observed in GAMMA 10 [T. Cho et al., Nucl. Fusion 45, 1650 (2005)]. The barrier is localized within a layer of a strongly sheared Er×B plasma rotation (5.5

  • Measurements of the plasma density in the FTU tokamak by a pulsed time-of-flight X-wave refractometer. Petrov, V.; Petrov, A.; Malyshev, A.; Benedetti, M.; Tudisco, O. // Plasma Physics Reports;Jan2008, Vol. 34 Issue 1, p24 

    On-line control over the plasma density in tokamaks (especially, in long-term discharges) requires reliable measurements of the averaged plasma density. For this purpose, a new method of density measurements—a pulsed time-of-flight plasma refractometry—was developed and tested in...

  • ELMy Studies in ITER Relevant Regimes in ASDEX Upgrade Broadband FM-CW Reflectometry Techniques. Manso, M.; Silva, A.; Varela, P.; Borba, D.; Lang, P.; Cupido, L.; Nunes, I.; Conway, G. // AIP Conference Proceedings;2006, Vol. 875 Issue 1, p363 

    We present a study performed in ASDEX Upgrade H mode regime based on results from the broadband FM-CW reflectometry diagnostic, equipped with the unique capability of measuring the plasma density profile both at the low and high field sides of the tokamak. The plasma edge dynamics due to fast...

  • Curvature particle pinch in tokamak and stellarator geometry. Mishchenko, Alexey; Helander, Per; Turkin, Yuriy // Physics of Plasmas;Oct2007, Vol. 14 Issue 10, p102308 

    A study of the curvature pinch effect in various fusion devices (both tokamaks and stellarators) is presented. Canonical density profiles are calculated employing the theory developed by M. B. Isichenko, A. V. Gruzinov, P. H. Diamond, and P. N. Yushmanov [Phys. Plasmas 3, 1916 (1995)]. In...

  • Parameters of turbulent structures at the periphery of the FT-2 tokamak. Shatalin, S.; Vekshina, E.; Vicente, J.; Vazhnov, P.; Esipov, L.; Lashkul, S.; Sidorov, A. // Plasma Physics Reports;May2011, Vol. 37 Issue 5, p371 

    Results are presented from probe measurements carried out in the scrape-off layer of the FT-2 tokamak in the course of additional lower hybrid heating, during which an L-H transition was observed. The objective of this study was to obtain information on the parameters of blobs-turbulent...

  • The existence of normal equilibrium in tokamaks with negative current in the column center. Pozdnyakov, Yu. I. // Physics of Plasmas;Aug2005, Vol. 12 Issue 8, p084503 

    Plasma rotation is shown to remove the impossibility of the existence of “normal” equilibrium in a tokamak with reversed current. The mathematical procedure of how to overcome the peculiarities, which appear in the equilibrium equations due to current reversal, is suggested. An...

  • Dynamical alignment in three species tokamak edge turbulence. Scott, Bruce D. // Physics of Plasmas;Aug2005, Vol. 12 Issue 8, p082305 

    Three-dimensional computations of self-consistent three species gyrofluid turbulence are carried out for tokamak edge conditions. Profiles as well as disturbances in dependent variables are followed, running the dynamical system to transport equilibrium. The third species density shows a...

  • Saturation levels of neoclassical tearing modes in International Thermonuclear Experimental Reactor plasmas. Lütjens, Hinrich; Luciani, Jean-François // Physics of Plasmas;Aug2005, Vol. 12 Issue 8, p080703 

    For the future ITER tokamak (International Thermonuclear Experimental Reactor) plasmas [R. Aymar et al., Nucl. Fusion 41, 1301 (2001)] a simple and robust theoretical model for the prediction of the dynamics of neoclassical tearing modes (NTM) is a crucial topic. Presently, this theory is...

  • Fast growing double tearing modes in a tokamak plasma. Bierwage, Andreas; Benkadda, Sadruddin; Hamaguchi, Satoshi; Wakatani, Masahiro // Physics of Plasmas;Aug2005, Vol. 12 Issue 8, p082504 

    Configurations with nearby multiple resonant surfaces have broad spectra of linearly unstable coupled tearing modes with dominant high poloidal mode numbers m. This was recently shown for the case of multiple q=1 resonances [Bierwage et al., Phys. Rev. Lett. 94 65001 (2005)]. In the present...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics