Pulse-burst laser-based 10 kHz Thomson scattering measurements

Thomson scattering (TS), as a popular and reliable diagnostic technique, has successfully measured electron temperatures and electron number densities of plasmas for many years. However, conventional TS techniques using Nd:YAG lasers operate only at tens of hertz. Here, we present the development of a high-repetition-rate TS instrument based on a high-speed, pulse-burst laser system to greatly increase the temporal resolution of measurements. Successful instrument prototype testing was carried out by collecting TS light from laboratory helium and argon plasmas at 10 kHz. Calibration of the instrument detection sensitivity using nitrogen/ oxygen rotational Raman scattering signal is also presented. Quantitative electron number densities and electron temperatures of the plasma were acquired at 10 kHz, for stable plasma discharges as, respectively, ∼0.9 eV and ∼5.37×10²¹ m⁻³ for the argon plasma, and ∼1 eV and ∼6.5×10²¹ m⁻³ for the helium plasma.