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Measurements of the plasma current density and q-profiles in IR-T1 tokamak
, Article Journal of Fusion Energy ; Volume 29, Issue 3 , June , 2010 , Pages 232-236 ; 01640313 (ISSN) ; Salar Elahi, A ; Abbaspour Tehrani Fard, A ; Tajdidzadeh, M ; Sharif University of Technology
2010
Abstract
The purposes of this paper are determination of the current density and safety factor profiles, J(r) and q(r), in IR-T1 tokamak. For these purposes, a diamagnetic loop with its compensation coil, and also an array of magnetic probes were designed, constructed, and installed on outer surface of the IR-T1 tokamak chamber, and then the poloidal beta and poloidal and radial magnetic fields measured. Moreover, a few approximate values of the internal inductance for the different possible profiles of the plasma current density are also calculated. From the results, current density and q-profiles obtained
Design, construction, and installation of movable electrode biasing system on tokamak
, Article Journal of Fusion Energy ; Volume 29, Issue 5 , 2010 , Pages 467-470 ; 01640313 (ISSN) ; Salar Elahi, A ; Tajdidzadeh, M ; Mohammadi, S ; Arvin, R ; Gheydi, M ; Abbaspour Tehrani Fard, A ; Sharif University of Technology
Springer New York LLC
Abstract
The first results of the movable electrode biasing experiments performed on the IR-T1 tokamak are presented. For this purpose, a movable electrode biasing system was designed, constructed, and installed on the IR-T1 tokamak, and then the positive voltage applied to an electrode inserted inside the tokamak limiter and 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 compared and discussed
Corrected formulation for estimation of ripple in large aspect ratio tokamaks
, Article Journal of Fusion Energy ; Volume 31, Issue 2 , 2012 , Pages 195-197 ; 01640313 (ISSN) ; Khorasani, S ; Sharif University of Technology
Abstract
The finite number of toroidal field coils of a tokamak destroys the perfect axisymmetry of the device. The coils produce a short wavelength ripple in the toroidal magnetic field strength as a field line follows round the torus, which becomes important in transport and confinement properties of plasma. Hence, a quick and accurate estimation of ripple becomes important. We have noticed that a previously reported analytical formulation by Princeton Plasma Physics Laboratory team is not applicable to our large aspect ratio tokamak, and have devised a slightly modified form which has greatly improved the accuracy of the analytical fit
Recent results of edge plasma parameters measurements in IR-T1 tokamak by probe
, Article Journal of Fusion Energy ; Volume 29, Issue 3 , June , 2010 , Pages 271-274 ; 01640313 (ISSN) ; Emami, M ; Ghoranneviss, M ; Abaspour Tehrani Fard, A ; Sharif University of Technology
2010
Abstract
Langmuir probes (LP) are the most common diagnostics for the local measurement of very important plasma parameters such as plasma density, electron temperature, plasma potential and the electron energy distribution function (EEDF). In this paper the applicability of the first derivative Langmuir probe method in processing the electron part of the current-voltage (I-V) characteristics in IR-T1 Tokamak is reported. The EEDF at different radial positions in the edge region and Scrape off Layer (SOL) are derived and the values of the plasma potential, electron temperature and electron density are estimated. Results comparison between the first derivative method and Stangeby method shows a...
Runaway electron energy measurement using hard x-ray spectroscopy in "damavand" tokamak
, Article Review of Scientific Instruments ; Volume 80, Issue 1 , 2009 ; 00346748 (ISSN) ; Iraji, D ; Farahbod, A. H ; Akhtari, K ; Rasouli, H ; Modarresi, H ; Lamehi, M ; Sharif University of Technology
2009
Abstract
Set of experiments has been developed to study existing runaway electrons in "Damavand" tokamak plasma upon characteristics of hard x-ray emissions produced by collision of the runaway electrons with the plasma particles and limiters. As a first step, spatial distribution of hard x-ray emissions on the equatorial plane of the torus was considered. Obtained spectra of hard x-ray emissions for different alignments of shielded detector indicate isotropic emissivity in the equatorial plane. This is in agreement with wide angle cone of bremsstrahlung radiations, deduced from the mean value of energy of the runaway electrons. The mean energy was calculated from the slope of the energy spectrum of...
MHD equilibrium and kink stability in Damavand tokamak
, Article Journal of Fusion Energy ; Volume 28, Issue 3 , 2009 , Pages 282-289 ; 01640313 (ISSN) ; Khorasani, S ; Sharif University of Technology
2009
Abstract
Magnetohydrodynamic (MHD) equilibrium is vulnerable to numerous destabilizing mechanisms. Instabilities introduce distortions to the plasma magnetic surfaces and its boundaries, their driving force being the radial gradient of plasma toroidal current density. For certain modal numbers, internal kink modes may develop, and their study is feasible according to the energy principle, in which the change in total potential energy due to the disturbance is evaluated. In this article, we present a totally new analysis of MHD equilibrium and stability, and apply it to Damavand tokamak which has a large aspect ratio. For this purpose, we combine perturbation and Green's function methods to solve for...