The first results of electrode biasing experiments in the IR-T1 tokamak

Abstract

We report here the first results of our movable electrode biasing experiments performed in the IR-T1 tokamak. For this study, a movable electrode biasing system was designed, constructed and installed on the IR-T1 tokamak. A positive voltage was applied to an electrode inserted in the tokamak limiter. The plasma current, poloidal and radial components of the magnetic fields, loop voltage and diamagnetic flux in the absence and presence of the biased electrode were measured. Results of the improvement done to plasma equilibrium behaviour are compared and discussed in this paper.

Application of multipole moments and magnetic techniques for determination of tokamak plasma shift

“…Therefore, an accurate determination of plasma column displacement during confinement is essential to transport it to a control system based on feedback. Over the years, different methods have been developed to analyze tokamak plasma equilibrium characteristics (Mukhovatov and Shafranov 1971;Shkarofsky 1982;Lee and Ghoranneviss 2001;Nakamura and Ghoranneviss 2003;Rahimi Rad et al 2009Seo 2009;Ghoranneviss and Salar Elahi 2010;Salar Elahi and Ghoranneviss 2010a, 2010b, 2010cGhanbari et al 2011aGhanbari et al , 2011bSalar Elahi 2011;Goodarzi et al 2013;Mikaili Agah et al 2013). In this paper, we will deduce the plasma current and plasma boundary centers shift using the two semi-empirical techniques in the IR-T1 tokamak.…”

“…However, in the second part, the two opposite forces (expansion force and Lorentz force due to the external vertical field) may not be equal and consequently the plasma intends to shift inward or outward, which is dangerous for the toroidal plasma. However, the toroidal plasma equilibrium study is one of the fundamental problems in the magnetically confined plasmas (Lee and Ghoranneviss 2001;Rahimi Rad et al 2009;Seo 2009;Ghoranneviss and Salar Elahi 2010;Salar Elahi andGhoranneviss 2010a, 2010b). In tokamak plasma equilibrium studies, there are many available experimental methods and analytical solutions for the steadystate Magneto Hydro Dynamics (MHD) equations, in particular the Grad-Shafranov equation.…”

“…Therefore, a precise determination of the plasma column shift during confinement is essential to transport it to a control system based on feedback. Over the years, different methods have been developed to analyze the toroidal plasma equilibrium problems (Ghoranneviss and Salar Elahi 2010;Rahimi Rad et al 2010;Salar Elahi and Ghoranneviss 2010c;Ghanbari et al 2011aGhanbari et al , 2011bGhanbari et al , 2012Salar Elahi 2011;Goodarzi et al 2013;Mikaili Agah et al 2013).…”

A confident source of hard X-rays: radiation from a tokamak applicable for runaway electrons diagnosis

“…of a chamber wall, escaping in large facilities of the tokamak type (Lipa et al, 2003). Runaway electrons colliding with residual plasma particles and the first wall are two sources of hard X-ray radiation in tokamaks (Naghidokht et al, 2016;, 2010aGhoranneviss et al, 2010;. Although the intensity of radiation due to collisions with heavy nuclei of the first wall is higher, in both cases the dominant mechanism is bremsstrahlung (Salar Elahi & Ghoranneviss, ,c,d,e,f, 2010f, 2014Salar Elahi et al, 2009b,c;Rahimi Rad et al, 2009;Ghanbari et al, 2014Ghanbari et al, , 2016Mikaili Agah et al, 2015a,b).…”

Design and construction of hot limiter biasing system for the tokamak

“…Limiter *Corresponding author. Email: ahmadsalari2005@yahoo.com bias has been used on IR-T1 tokamak to investigate the possibility of modifying the plasma confinement and edge plasma rotation (11). It has been shown that both positive and negative limiter and electrode bias can modify the plasma behavior.…”