Characterization of the pulse-burst laser system for high-repetition-rate Thomson scattering

Summary form only given, as follows. A pulse-burst laser has been installed for Thomson scattering measurements on MST. The laser design is a master-oscillator power-amplifier which is capable of Q-switching at frequencies between 5–250 kHz. A burst of laser pulses consists of a single flashlamp pulse ranging between 200 µs–20 ms and the master-oscillator delivering between 10–200 pulses. At small flashlamp pulse lengths 200–300 µs, the system can deliver multiple bursts at rates up to 1 kHz. Single pulses through the first (four) Nd:YAG amplifier stages give energies up to 1.5 J, and the gain for each stage has been measured. Repetitive pulsing at 10 kHz has also been performed with these amplifier stages for 2 ms bursts giving average pulse energies of 0.53 J with ΔE/E of 4.6%, where ΔE is the standard deviation between pulses. Successful operation of the first Nd:glass amplifier stage has been demonstrated and its performance will be evaluated. Additionally, the beam path has also been extended to the MST vacuum vessel for electron temperature measurements.