Abstract
The main magnetic fields in COMPASS - i.e. The Toroidal, Magnetising, Equilibrium, and Shaping Fields - are created by a set of four corresponding thyristor power supplies controlled in a 0.5 ms loop.
The plasma position has to be controlled both radially and vertically by two additional magnetic fields provided by two fast amplifiers (FAs) based on MOSFET technology, each supplying +/- 100 V and up to +/- 5 kA. Currently, an ongoing project aims at ELM triggering by fast changes of the vertical position of the plasma column, also referred to as vertical kicks.
For this purpose, a new Vertical Kicks Power Supply (VKPS) capable of quick change of vertical plasma position is being constructed. This power supply should operate at up to 1.2 kV with switching frequency up to 5 kHz.
It is designed as a H-bridge but based on IGBT transistors which can be operated at higher voltages than MOSFETs. In this paper, we focus on the FAs and VIC'S engineering design and required output parameters.
Both the power supplies are based on modern components with highest available ratings in their categories. Unique design of the power supplies takes advantage of the short duration of the COMPASS discharge by overloading the transistors above their maximal steady-state rating.
The FA is regularly operating, so that in addition to describing its design, we also describe the achieved performance parameters. Finally, the common controller unit, communication, and error handling is described. (C) 2013 Institute of Plasma Physics ASCR, v.v.i.
Association EURATOM. Published by Elsevier B.V.
All rights reserved.