Fast imaging of laser-blow-off plume: Lateral confinement in ambient environment

Abstract

The dynamics of plasma plume, formed by the laser-blow-off of multicomponent LiF-C thin film under various ambient pressures ranging from high vacuum to argon pressure of 3 Torr, has been studied using fast imaging technique. In vacuum, the plume has ellipsoidal shape. With the increase in the ambient pressure, sharp plume boundary is developed showing a focusing-like (confinement in the lateral space) behavior in the front end, which persists for long times. At higher ambient pressure (>10−1 Torr), structures are developed in the plasma plume due to hydrodynamic instability/turbulences.

Influence of laser beam intensity profile on propagation dynamics of laser-blow-off plasma plume

“…The plume expansion in vacuum under the influence of pressure gradient inside ablated plume is treated as adiabatic expansion (Singh & Narayan, 1990), where the thermal energy of plume species is rapidly converted into the kinetic energy. This leads to decrease in electron temperature and density with time and hence decrease in electron impact process (George et al, 2009). Therefore, considerable reduction in the emission intensity of the plume with increase in the time delay can be anticipated.…”

“…Plasma plume formed by laser-blow-off (LBO) technique (Adrian et al, 1987;Bakos et al, 1992;Veiko et al, 2006;George et al, 2009;Kumar et al, 2010), where the laser beam interacts with a thin film of target material supported on a thick transparent substrate, is used to generate short bursts of high intensity, neutral atomic/ionic beams. This technique is extensively used for neutral atomic beam injection in plasma as a diagnostic tool, impurity transport studies for the high temperature Tokamak plasma (Huber et al, 2005) and as a source of metallic atomic beam for accelerators (Doria et al, 2004).…”

Plume splitting and rebounding in a high-intensity CO2 laser induced air plasma

“…In particular, the phenomenon of plasma "plume splitting" has been reported previously in a number of experiments. [8][9][10][11] This phenomenon results in a distinct two part velocity distribution within the plasma, termed the "fast" and the "slow" components. In parallel to pulsed laser-solid interactions, the study of laser-induced gas plasma [12][13][14][15] is also important in diagnosing the mechanisms present in laser generated plasma plume dynamics.…”

Parametric study of expanding plasma plume formed by laser-blow-off of thin film using triple Langmuir probe

“…5 In the recent past, we have made attempts to characterize the LBO generated plasma plume using different diagnostic techniques, for example, optical emission spectroscopy ͑OES͒, 4-7 times resolved fast photography, 8 fast charge collector, 9 and single Langmuir probe ͑LP͒. 10 The results obtained by these diagnostic techniques give the complementary information about the LBO plume with regard to the expansion dynamics in different regions, structural information, and electron density and temperature.…”