Installation and commissioning of SST-1 Thomson scattering system

SST-1 Thomson scattering (TS) system is designed with 6 Nd:YAG lasers of 1.6 J energy each at the fundamental wavelength of 1064 nm. The 90 degree scattered photons are imaged to an array of optical fibers which transfer the photons for spectral dispersion and detection to a five channel interference filter polychromator. Avalanche photodiodes with nearly 3 mm active area are being used for the signal detection along with appropriate signal conditioning electronics and data acquisition. The commissioning of 6 laser system is in progress. At present, a single laser based TS system with 1.6 J energy at 30 Hz has been commissioned in SST-1 with 5 spatial points having spatial resolution around 10 mm. Inter channel calibration of filter polychromator and absolute calibration of Thomson scattering system has been performed. We discuss the data from different calibrations performed for commissioning of a single laser based Thomson scattering system on SST-1. (author)