Spectroscopic, imaging, and probe diagnostics of laser plasma plumes expanding between confining surfaces

Journal Article · Mon Nov 15 00:00:00 EST 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3505801· OSTI ID:21476598

Yeates, P ^[1]; Kennedy, E T ^[2]

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1. National Centre for Plasma Science and Technology, Dublin City University, Dublin 9 (Ireland)
2. School of Physical Sciences, Dublin City University, Dublin 9 (Ireland)

Laser plasma plumes were generated in aluminum rectangular cavities of fixed depth (6 mm) and varying height (2.0, 1.5, and 1.0 mm). Space and time resolved visible emission spectroscopy, gated intensified visible imaging, and Langmuir probe diagnostics were utilized to diagnose the evolution of the confined plasma plumes in comparison to freely expanding plasma plume generated from ablation of a planar target. The constrained plasma behavior displayed a multiphase history. Early stage interactions (t<100 ns) resulted in enhanced continuum and line emission, shockwave formation and plasma plume rebound. Later phase, long duration plasma-surface interactions (t>160 ns) resulted in sustained 'decay', i.e., a rapid termination of continuum emission, in concert with decreases in peak electron density (N{sub e}) and plasma temperature (T). This later phase originates from loss mechanisms which bleed the plasma plume of thermal energy and charged particles. These loss mechanisms increase in magnitude as the duration of the plasma-surface interaction increases. The transition from enhancement phase, originating from hydrodynamic containment, and plasma-surface collisions, to decay phase is described and occurs for each cavity at a different point in the space time history.

• OSTI ID: 21476598
• Journal Information: Journal of Applied Physics, Vol. 108, Issue 9; Other Information: DOI: 10.1063/1.3505801; (c) 2010 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ABLATION
ALUMINIUM
CHARGED PARTICLES
COMPARATIVE EVALUATIONS
ELECTRON DENSITY
ELECTRON TEMPERATURE
EMISSION SPECTROSCOPY
ION TEMPERATURE
LANGMUIR PROBE
LASER-PRODUCED PLASMA
PLASMA CONFINEMENT
PLASMA DENSITY
PLASMA DIAGNOSTICS
PLASMA PRODUCTION
SHOCK WAVES
TIME RESOLUTION
WALL EFFECTS
CONFINEMENT
ELECTRIC PROBES
ELEMENTS
EVALUATION
METALS
PLASMA
PROBES
RESOLUTION
SPECTROSCOPY
TIMING PROPERTIES