Analysis of the radial and poloidal turbulent transport in the edge tokamak plasma

Abstract

In 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.

The Study of Surface Properties of Tokamak First Wall Using TiN Coated on Stainless Steel

“…This device consists of a vacuum vessel with circular cross-section that was made from a stainless steel welding structure with two toroidal breaks and a minor radius b = 15 cm [13][14][15]. IR-T1 Tokamak chamber has been made of the stainless steel 316L (S.S.316L).…”

“…The plasma current and loop voltage are measured by Rogowski coil and loop voltage coil. Electron temperature is calculated by Langmuir-Ball Pen Probe (LBPP) using the method mentioned in earlier researches of IR-T1 group [13][14][15].…”

Development of an Innovative Mix-Probe for Spatio-Temporal Measurements of Vorticity Fluctuations in the IR-T1 Tokamak

“…Additionally, plasma density fluctuations were detected by LP tips, which was in the ion saturation state. With the calculation of the electric field from the floating potential [27], the radial velocity and its shearing rate can be obtained using this Mix-Probe. Signals from LP2, LP3, and LP4 have been sampled at 20 MHz, while the other pins were sampled at 2 MHz.…”