Abstract:
A high-energy and high-frequency laser with 1 064 nm and 532 nm laser pulses is designed to diagnose the plasma electron temperature and density in the core and boundary regions of EAST Thomson scattering diagnostic system, respectively. We use electro-optic Q-switching, Cassegrain unstable cavity and xenon lamp pumped pulse amplifier to output a frequency of 100 Hz and an energy of 3.5 J@1064 nm laser pulse. The fundamental frequency optical energy is amplified by two-stage semiconductor side pump module to output laser energy of 5.5 J@1064 nm. Through theoretical calculation and analysis, the amplification capacity of the pump module is determined and compared with the experimental results. LBO crystal is used to double the fundamental frequency light, and the output energy is 3 J@532 nm pulse laser, the frequency doubling efficiency is 55%. The diameter of the output fundamental frequency light spot is about 14.51 mm, the pulse width is 11.90 ns, the diameter of the frequency doubling light spot is about 17.81 mm, the pulse width is 9.92 ns, and the laser pulse is Gaussian flat top distribution. The repetition rate is adjustable from 1 Hz to 100 Hz, and the spatial resolution of Thomson scattering diagnostic is up to 10 ms, which provides conditions for the study of microphysical problems such as core and boundary transport barrier.