Effect of rotating helical magnetic field on the turbulence fractal structure and transport in the tokamak edge plasma

2004 ◽  
Vol 44 (6) ◽  
pp. S108-S117 ◽  
Author(s):  
V Budaev ◽  
Y Kikuchi ◽  
Y Uesugi ◽  
S Takamura
2003 ◽  
Vol 313-316 ◽  
pp. 1309-1313 ◽  
Author(s):  
V.P. Budaev ◽  
Y. Kikuchi ◽  
M. Toyoda ◽  
Y. Uesugi ◽  
S. Takamura

2013 ◽  
Vol 84 (5) ◽  
pp. 053504 ◽  
Author(s):  
Mansoureh Lafouti ◽  
Mahmood Ghoranneviss ◽  
Sakineh Meshkani ◽  
Ahmad Salar Elahi

2015 ◽  
Vol 81 (3) ◽  
Author(s):  
Sakineh Meshkani ◽  
Mahmood Ghoranneviss ◽  
Mansoureh Lafouti

For understanding the effect of resonant helical magnetic field (RHF) and bias on the edge plasma turbulent transport, the radial and poloidal electric field (Er, EP), poloidal and toroidal magnetic field (BP, Br) were detected by the Langmuir probe, magnetic probe and diamagnetic loop. The poloidal, toroidal and radial velocity (VP, Vr, Vt) can be determined from the electric and magnetic field. In the present work, we have investigated the effect of the magnitude of bias (Vbias = 200v, Vbias = 320v) on Er, EP, BP, Bt, VP, Vr, Vt. Moreover, we applied RHF with L = 2, L = 3 and L = 2 and 3 and investigate the effect of the helical windings radius on above parameters. Also, the experiment was repeated by applying the positive biasing potentials and RHF's simultaneously. The results show that by applying bias to the plasma at t = 15 msec at r/a = 0.9, Er, BP and Bt increase while EP decreases. The best modification occurs at Vbias = 200v. By applying RHF to the plasma, both the electric and magnetic field vary. Er reaches the highest in the presence of RHF with L = 3. The same results are obtained for BP, Bt, VP and Vt. While the inverse results are obtained for EP and Vr. Finally, RHF and bias are applied simultaneously to the plasma. With applied bias with Vbias = 200v and RHF with L = 2 and 3, we reach to the ideal circumstance. The same results obtain in the situation with Vbias = 320v and RHF with L = 2 and 3.


2013 ◽  
Vol 79 (5) ◽  
pp. 647-655 ◽  
Author(s):  
S. MESHKANI ◽  
M. GHORANNEVISS ◽  
M. LAFOUTI ◽  
A. SALAR ELAHI

AbstractIn this paper, turbulent transport in the edge plasma of the IR-T1 tokamak (r/a = 0.9) in the presence of a resonant helical magnetic field (RHF) and a biased limiter has been investigated and analyzed. The time evolution of potential fluctuation, and electric field and turbulent transport have been measured by using two arrays of the Langmuir probes in both the radial and poloidal directions. The experiments have been done in different regimes such as limiter biasing and RHF, and both of them. The analyses have been done by the fast Fourier transport method and their spectral features are obtained with the help of the standard autocorrelation technique. The results show that radial turbulent transport decreases about 60% after positive biasing application, while it increases about 40% after negative biasing. The effect of positive biasing on poloidal turbulent transport displays an increase of about 55%, while the negative bias voltage decreases the poloidal turbulent transport about 30%. Consequently, confinement is improved and plasma density rises significantly due to the applied positive biasing in IR-T1. However, the results are reversed when negative biasing is applied. Also, in this work, the results of the applied RHF (L = 3) are compared with biasing results and analyzed.


2018 ◽  
Vol 58 (6-8) ◽  
pp. 688-695 ◽  
Author(s):  
G. Giorgiani ◽  
T. Camminady ◽  
H. Bufferand ◽  
G. Ciraolo ◽  
P. Ghendrih ◽  
...  

2015 ◽  
Vol 6 (1-2) ◽  
pp. 86-91
Author(s):  
S. I. Krasheninnikov ◽  
J. Guterl ◽  
W. Lee ◽  
R. D. Smirnov ◽  
E. D. Marenkov ◽  
...  

1997 ◽  
Vol 4 (9) ◽  
pp. 3436-3438 ◽  
Author(s):  
V. S. Tsypin ◽  
S. V. Vladimirov ◽  
A. G. Elfimov ◽  
M. Tendler ◽  
A. S. de Assis ◽  
...  

2002 ◽  
Vol 54 (3) ◽  
pp. L39-L43 ◽  
Author(s):  
Keiichi Asada ◽  
Makoto Inoue ◽  
Yutaka Uchida ◽  
Seiji Kameno ◽  
Kenta Fujisawa ◽  
...  

2010 ◽  
Vol 19 (06) ◽  
pp. 917-922
Author(s):  
JOSÉ L. GÓMEZ ◽  
MAR ROCA-SOGORB ◽  
IVÁN AGUDO ◽  
ALAN P. MARSCHER ◽  
SVETLANA G. JORSTAD

We present a sequence of 12 monthly polarimetric multi-frequency VLBA observations of the radio galaxy 3C 120. The motion of multiple superluminal components allows the mapping of the polarization structure along most of the jet and across its width, revealing a coherent in time Faraday screen and RM-corrected polarization angles. Gradients in Faraday rotation and degree of polarization across the jet are observed, together with a localized region of high rotation measure superposed on this structure. This is explained as produced by the presence of a helical magnetic field in a two-fluid jet model, consisting of an inner emitting jet and a sheath containing nonrelativistic electrons. Interaction of the jet with the external medium would explain the confined region of enhanced Faraday rotation.


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