Time-resolved two-dimensional measurements of the electron density, electron temperature, and drift velocity of laser-produced carbon plasmas using the ion feature of collective laser Thomson scattering

Abstract

Temporal evolutions of two-dimensional (2D) plasma profiles produced by Nd:YAG laser ( 5.9 × 10 9 W cm − 2 , 8 ns FWHM) were investigated at 5–25 ns after the laser peak at 0.2–0.5 mm from the initial target surface by measuring the electron density (n e), temperature (T e), and drift velocity (V d). The T e profiles were nonuniform and showed a peak at 0.3 to 0.4 mm above the target surface. The high-temperature region of the plasma moved outward at the same speed as that of the expansion of the plasma, indicating the isothermal expansion ends immediately after the ablation pulse. The 2D profiles of V d and pressure also show that the plasma expanded anisotropically.

Science-based, data-driven developments in plasma processing for material synthesis and device-integration technologies

“…45) The temporal variation in 2D measurements of electron density and electron temperature was reported in the case of laser-produced plasma, although it is slightly different from that in high-pressure plasma, using collective Thomson scattering with ion features. 46) Optical emissions can be measured relatively simply and are commonly diagnosed by analysis using the collisional radiative model. 47,48) Emissions of two excitation energy levels can be drawn on an electron density and electron temperature plane; thus, a pair of density and temperature can be obtained at an intersection point on the contour plane.…”

Comparative study of the decay process of LIP and gas arc in SF6/N2 gas mixture by Thomson scattering

“…Considering the characteristics of the SF 6 /N 2 gas mixture, studying both plasma types offers valuable insights. For LIP diagnostics, prior research has obtained the evolution properties of electron density and temperature throughout the LIP decay process in argon and air environments using LTS [26][27][28][29][30]. Tomita et al have measured the decay characteristics of gas arc within SF 6 /Ar mixture, employing LTS under the specific conditions of gas-blast nozzle constraints [31][32][33].…”

Two-color laser scattering for diagnostics of hydrogen plasma

“…It has also played an important role in studies of fusion plasmas [25][26][27][28] where it is still the most reliable method for measuring electron temperature. Last but not least, it has been used to study laser-induced plasmas [29][30][31][32][33][34][35][36] of both low and high temperatures, the latter being related to inertial-confinement fusion research.…”