Interaction of laser ablation plasma plume with grid screens

Abstract

Optical emission spectroscopy and charge collector time-of-flight measurements have been used to study interaction of laser ablation carbon plasma with grid screens in vacuum under conditions typical for pulsed laser deposition of thin diamondlike films. The effect of velocity distribution transformation of the ion flow has been observed and studied in a variety of experimental conditions. Our results indicate that the observed phenomenon is due to interaction of two plasma flows, the initial expanding one and the fraction of that flow scattered by the substrate or the screen. Three typical modes of velocity distribution function transformation have been observed depending on the plasma density: linear attenuation of the flow density, nonlinear attenuation of the slow ‘‘tail’’ of the velocity distribution function, and nonlinear transformation of the entire velocity spectrum. The latter regime occurs when plasma is throttling through the fine mesh screen. Our observations show that the reported phenomenon may substantially affect deposited film properties.

Temporal and spatial evolution of C2 in laser induced plasma from graphite target

“…In order to understand the processes leading to cluster formation, which may directly influence laser deposition, the mechanism of plasma plume generation from the target material under laser irradiation and the interaction of the resulting plume with the ambient atmosphere in the plasma chamber should be studied in detail. There are several techniques for characterizing laser induced plasma and these include optical emission spectroscopy, [25][26][27] optical absorption spectroscopy, 28,29 laser induced fluorescence, 30,31 time resolved spectroscopy, 32 mass spectroscopy 3 etc. Among these, time resolved spectroscopy is the most suitable method to study the dynamics of laser produced plasma.…”

Microscopic description of the thermalization process during pulsed laser deposition of aluminium in the presence of argon background gas

“…where n is the number density of the gas and σ is the ion-atom collision cross section (σ ≈ 10 −15 cm 2 ) [28]. If we set n equal to P /kT , where P and T are the pressure and temperature of the ambient gas and k is the Boltzmann constant, then L would read as…”