Expansion dynamics of laser produced plasma

Abstract

We consider the applicability of the isentropic, adiabatic gas dynamical model of plume expansion for laser ablation in vacuum. We show that the model can be applied to ionized plumes and estimate the upper electron temperature limit on the applicability of the isentropic approximation. The model predictions are compared with Langmuir ion probe measurements and deposition profiles obtained for excimer laser ablation of silver.

Angular ion species distribution in droplet-based laser-produced plasmas

“…The gas-dynamic model yields a density and temperature distribution close to the experimental results in the first phase of the plasma expansion and in the core of the plasma, where the quasineutral assumption is valid. [27][28][29] For this reason, it could already be successfully used to numerically map the EUV emission distribution around the droplet target. 3 In order to model the ion expansion at larger distances, one main physical process is missing.…”

Estimation of Requirements for the Formation of Nanocrystalline Diamond Driven by Electron Beam Ablation

“…The analysis is based on a special solution of the equations assuming an adiabatic expansion of the plasma and when the flow is self-similar. The special solution has been extended to plasma expansion into a background gas provided that the background gas pressure is low, i.e., at most a few 10 −1 Pa [14], [15]. This is the case of PEBA, where the gas pressure is within the range of ∼0.10-2.5 Pa.…”

“…1, whose semiaxes are initially equal to X o , Y o , and Z o ≈ c s τ , where τ is the duration of the electron-beam pulse and c s is the speed of sound in the vaporized material and given by c s = [γ (γ − 1)ε] 1/2 , where γ is the ratio of the usual specific heats. The expression of the pressure and temperature profiles at the top of the plasma plume (x = 0, y = 0, z = z) can be expressed as [13]- [15] …”

“…A value of 1.25 is used for γ [15]. In order to calculate the temperature and pressure, the values of X, Y , and Z are needed.…”

Modelling the creation of surface nano-structures using test charge approach

“…Plasma expansion [1,2], has attracted attention as a means of explaining the increase of temperature in devices. Research in the field began in 1945 by Landau [3] and since then has developed considerably.…”