1. Culham Centre for Fusion Energy , Tritium Engineering & Science Group, Abingdon, Oxfordshire, OX14 3DB
2. Culham Centre for Fusion Energy , JET Exploitation Unit, Abingdon, Oxfordshire, OX14 3DB
3. Universidade de Lisboa , Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Lisboa P-1049-001, Portugal
4. Culham Centre for Fusion Energy , Abingdon, Oxfordshire, OX14 3DB