**3.2. Large magnetic field coils**

The main vessel is equipped with two magnetic coils in a Helmholtz configuration. The distance between the coils is about 815 mm. Some of the characteristics are given in **Table 1**. The outer/inner diameter is 2200/1200 mm and the thickness varies between 120 and 180 mm. The coils are connected to the central high current supply of the institute, which uses two modules connected either in parallel or in series using regular electrical voltage at 10.5 kV at 50 Hz. The magnetic (B) field in the centre of the vacuum vessel is expected to be 0.1 T for a current of 2.4 kA in the main coils. Higher currents and fields are possible. The current generator can sustain 4 kA for 10s and 12kA for 1 s, corresponding with B-fields up to 0.275 and 0.4 T respectively.
