Speaker
Mr
Umesh Kumar
(Institute for Plasma Research, Gandhinagar, Gujarat, India)
Description
A simple toroidal device (SMT) is a toroidal device in which plasma is
confined by the application of toroidal and vertical magnetic field only
resulting in absence of a conventional effective rotational transform. Such
devices provide a simple and well diagnosable test-bed for studies related
to equilibrium, fluctuations and particle confinement for Tokamak edge.
The device BETA at the Institute for Plasma Research (IPR) is one such
SMT with a plasma major radius of 45 cm and minor radius of 15 cm and a
maximum toroidal field of 0.1 Tesla. Quasi-static equilibrium in an SMT is
controlled by the nature of fluctuation and flow [1, 2]. As observed in hot
cathode discharges studied earlier [1, 2], density gradient provide
fluctuation in the plasma and hence the instabilities [2]. Whereas radial
electric field provides poloidal flow. Thus, the conditions are akin to
Tokamak edge.
To experimentally understand the effect of the density gradient, it is
desirable to be able to control the local gradient at the outboard side by
an additional plasma source. To this end, a new microwave source of
frequency 2.4 GHz and power about 0.5 kW has been developed [3]. Hot
cathode and microwave sources are used in tandem such that the upper
hybrid resonance falls at the outboard density gradient region, which in
turn allows us to control the density gradient locally. The details of the
experiment will be presented.
References
[1] T. S. Goud, Thesis, Institute for Plasma Research, Gandhinagar,
Gujarat, India (2012).
[2] Umesh Kumar, Shekar G Thatipamula, R. Ganesh, Y. C. Saxena and D.
Raju, Phys. Plasmas 23, 102301 (2016).
[3] Umesh Kumar, R. Ganesh, K. Sathyanarayana, Y. C. Saxena, S. G.
Thatipamula, D. Raju , Manuscript under preparation
| Country or International Organization | India |
|---|---|
| Paper Number | EX/P2-6 |
Primary author
Mr
Umesh Kumar
(Institute for Plasma Research, Gandhinagar, Gujarat, India)
Co-authors
Dr
Rajaraman Ganesh
(Institute for Plasma Researh, Bhat Village, Gandhinagar 382428, Gujarat, INDIA)
Dr
Raju Daniel
(Institute for Plasma Research, Gandhinagar, India)
Mr
Sathyanarayana Krishnamachari
(Institute for Plasma Research, Gandhinagar, India)
Dr
Shekar G. Thatipamula
(National Fusion Research Institute, Daejeon, South Korea)
Prof.
Yogesh C. Saxena
(Institute for Plasma Research, Gandhinagar, India)
