Neutronics analyses for EU-DEMO 2023 electron cyclotron port

One of the fundamental challenges in the development of a fusion power plant is to integrate all the systems required for the operation of the power plant into a machine that fulfills all the design requirements. This includes designing sufficient shielding against neutrons and gamma rays to ensure that the machine can operate reliably throughout its planned lifetime.

The electron cyclotron (EC) heating is one of the systems critical to heating and controlling the fusion plasma. In the EU-DEMO reactor, the EC system is integrated into an equatorial port. However, the challenge with this system is that the waveguides required for it to function act as neutron and gamma ray streaming paths, which makes controlling the nuclear loads inside and behind the EC port a challenge. This concerns both the components of the EC system itself and components and systems outside the equatorial port where the EC system is located, e.g. the superconducting toroidal field coils.

The latest iteration of the EU-DEMO EC heating system from 2023 was analyzed. The main nuclear loads have been calculated and the shielding performance optimized to ensure that the design limits are met. These analyses include calculations of nuclear heating in EC port, determination of peak nuclear heating in the toroidal field coils and peak neutron-induced damage (DPA) in the components exposed to the plasma neutrons.