skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Role of ambient gas and laser fluence in governing the dynamics of the plasma plumes produced by laser blow off of LiF-C thin film

Abstract

The time- and space-resolved emission profiles of Li I and Li II emission lines from the laser-blow-off plumes of a multilayered LiF-C thin film have been studied using spectroscopic technique. The evolution features were analyzed in different ambient environments ranging from high vacuum to 3 mbars of argon pressures and at various fluences of the ablating laser. During the evolution of the plume, a transition region was found to exist between 4 and 6 mm. Here, the plume dynamics changed from free expansion to collisional regime, where the plume experienced viscous force of the medium. The enhancement observed in neutral lines, in comparison with ionic lines, is explained in terms of the yield difference in electron impact excitation and ionization processes. Substantial difference in the arrival time distribution of the plume species was observed for Li I and Li II lines at high ambient pressures. Three expansion models are invoked to explain the evolution of the plume in different ambient conditions. The laser fluence was found to control the ratio of ions and neutrals.

Authors:
; ; ;  [1];  [2]
  1. Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)
  2. (India)
Publication Date:
OSTI Identifier:
20982875
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 101; Journal Issue: 10; Other Information: DOI: 10.1063/1.2732446; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ABLATION; ARGON; CARBON; ELECTRON BEAMS; EVOLUTION; EXCITATION; ION EMISSION; IONIZATION; LASERS; LITHIUM FLUORIDES; PLASMA; PLASMA DIAGNOSTICS; PLUMES; THIN FILMS

Citation Formats

Singh, R. K., Kumar, Ajai, Patel, B. G., Subramanian, K. P., and Physical Research Laboratory, Navrangpura, Ahmedabad 380009. Role of ambient gas and laser fluence in governing the dynamics of the plasma plumes produced by laser blow off of LiF-C thin film. United States: N. p., 2007. Web. doi:10.1063/1.2732446.
Singh, R. K., Kumar, Ajai, Patel, B. G., Subramanian, K. P., & Physical Research Laboratory, Navrangpura, Ahmedabad 380009. Role of ambient gas and laser fluence in governing the dynamics of the plasma plumes produced by laser blow off of LiF-C thin film. United States. doi:10.1063/1.2732446.
Singh, R. K., Kumar, Ajai, Patel, B. G., Subramanian, K. P., and Physical Research Laboratory, Navrangpura, Ahmedabad 380009. Tue . "Role of ambient gas and laser fluence in governing the dynamics of the plasma plumes produced by laser blow off of LiF-C thin film". United States. doi:10.1063/1.2732446.
@article{osti_20982875,
title = {Role of ambient gas and laser fluence in governing the dynamics of the plasma plumes produced by laser blow off of LiF-C thin film},
author = {Singh, R. K. and Kumar, Ajai and Patel, B. G. and Subramanian, K. P. and Physical Research Laboratory, Navrangpura, Ahmedabad 380009},
abstractNote = {The time- and space-resolved emission profiles of Li I and Li II emission lines from the laser-blow-off plumes of a multilayered LiF-C thin film have been studied using spectroscopic technique. The evolution features were analyzed in different ambient environments ranging from high vacuum to 3 mbars of argon pressures and at various fluences of the ablating laser. During the evolution of the plume, a transition region was found to exist between 4 and 6 mm. Here, the plume dynamics changed from free expansion to collisional regime, where the plume experienced viscous force of the medium. The enhancement observed in neutral lines, in comparison with ionic lines, is explained in terms of the yield difference in electron impact excitation and ionization processes. Substantial difference in the arrival time distribution of the plume species was observed for Li I and Li II lines at high ambient pressures. Three expansion models are invoked to explain the evolution of the plume in different ambient conditions. The laser fluence was found to control the ratio of ions and neutrals.},
doi = {10.1063/1.2732446},
journal = {Journal of Applied Physics},
number = 10,
volume = 101,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}