Grounding and cabling aspects inside the ITER cryostat

The experimental fusion reactor ITER presents a number of special ElectroMagnetic Compatibility issues. Earlier tokamaks like JET applied single point grounding of the electronics for measurement and control. This is impossible for ITER because of its size and complexity and the all metal heart of the machine. Outside the cryostat a meshed grounding has been selected and will be implemented throughout. The circumstances inside the cryostat with large magnetic fields B and time-derivatives dB/dt require careful cable selection and routing: the loop controlled zone. Other aspects are required reliability in spite of limited space and no access after installation. This paper discusses several issues of grounding and cabling inside the cryostat.