  In future nuclear fusion reactors high heat load events, such as
edge-localised modes (ELMs), can potentially damage divertor materials and
release impurities into the main plasma, limiting plasma performance. The most
difficult to handle are type I ELMs since they carry the largest fraction of
energy from the plasma and therefore deposit the largest heat flux at the
target and on first wall materials. Knowing the temperature of the ions
released from ELM events is important since it determines the potential
sputtering they would cause from plasma facing materials. To make measurements
of Ti by retarding field energy analyser (RFEA) during type I ELMs a new
operational technique has been used to allow faster measurements to be made;
this is called the fast swept technique (FST).
