Fast Ion Loss Detectors
In order to identify plasma fluctuations which cause losses of fast ions, Fast Ion Loss Detectors (or FILD) are required. The detectors provide velocity-space measurements of escaping ions with a temporal resolution in the order of milliseconds.
The detectors must be very close to the plasma, in an area with extreme heat loads very close to the plasma when operating. In order to avoid damage they are mounting on a retractable arm, which moves towards the plasma for short periods when measurements are being taken.
The detectors themselves are scintillator based, emitting light when hit by fast ions. The light emitted by the scintillators will be collected by the light acquisition system, where it will be recorded by a fast visible camera.