Detection of Dust on JET with the High Resolution Thomson Scattering Systems
Dust particles have been observed with Thomson Scattering on several tokamaks. We present here the first evidence of dust particles observed by the new High Resolution Thomson Scattering system on JET. The system consists of filter spectrometers that analyze the TS spectrum from 820-1062nm in 4 spectral channels. The laser source is a 5J Q-switched Nd:YAG laser. Without a spectral channel at the laser wavelength, only dust particles that emit broad band light emission could be detected, these particles have been observed on JET after disruptions. The timing of their emission is clearly different from that expected for a Thomson scattering pulse, as the light pulse from dust is much longer, it peaks after the peak of the incident light and has a long tail.