Scintillator probe diagnostic for high energy particles escaped from Large Helical Device

A scintillator probe for escaping fast ion diagnostics has been developed in the Large Helical Device. This probe is capable of traveling across a divertor leg and sweeping the aperture angle rotationally with respect to the axis of the probe shaft. Pitch angle and gyro radius resolutions are estimated numerically by using a Monte Carlo orbit simulation. The result shows that the detector has sufficient resolution in pitch angle and gyro radius for our target plasmas. Under the neutral beam injected plasma, a signal derived from fast ions was obtained on the scintillator plate and analyzed by using the recorded camera image.