Diagnostic optics for fusion research

Louise Smyth

Optical Surfaces Ltd has received a sizeable order from the Culham Centre for Fusion Energy (CCFE) to manufacture the relay imaging reflective optics that will form part of two critical viewing diagnostic assemblies for the Joint European Torus (JET) when operating with a deuterium-tritium fuel mixture. The project is funded under the framework of EUROfusion**.

Comprising a series of large diameter (up to 500mm) ultra-smooth flat and spherical mirrors, some of which will have a very long radius of curvature, the relay imaging reflective optics will allow CCFE to monitor a number of physical and operational parameters within the JET fusion vessel with remote cameras from behind the 3m thick concrete shield wall. Knowledge of these parameters will ensure safe and smooth operation during JET’s planned campaign of fusion experiments using a deuterium-tritium fuel mixture. The relay imaging will be performed mainly with reflective optics because these are resilient to the hostile conditions that high energy neutrons and radiation present to them inside the Torus Hall.

CCFE is the UK's national laboratory for fusion research. CCFE is owned and operated by the United Kingdom Atomic Energy Authority (UKAEA). CCFE hosts JET - the world's largest magnetic fusion experiment - on behalf of its European partners. The JET facilities are collectively used by European fusion scientists, co-ordinated under EUROfusion. 

Dr Tim May-Smith, Diagnostics Support Physicist/Engineer at CCFE, said: "Selecting a supplier to manufacture the component optics was a very important decision because of the critical role that the relay cameras will play in the safe operation of JET. Optical Surfaces Ltd. was our selected supplier because of their experience and knowledge in the area of large optics, precision manufacturing expertise and value-for-money offered”.

**  The EUROfusion consortium is the organisational body of fusion energy research in Europe, funded by the Euratom Horizon 2020 programme and additionally from EU member states.