Ion flux enhancements and oscillations in spatially confined laser produced aluminum plasmas

Journal Article · Mon Sep 15 04:00:00 EDT 2014 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4895601· OSTI ID:22303444

Fallon, C.; Hayden, P.; Yeates, P.; Costello, J. T. ^[1]; Mujawar, M. ^[2]

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

Ion signals from laser produced plasmas (LPPs) generated inside aluminum rectangular cavities at a fixed depth d = 2 mm and varying width, x = 1.0, 1.6, and 2.75 mm were obtained by spatially varying the position of a negatively biased Langmuir probe. Damped oscillatory features superimposed on Maxwellian distributed ion signals were observed. Depending on the distance of the probe from the target surface, three to twelve fold enhancements in peak ion density were observed via confinement of the LPP, generated within rectangular cavities of varying width which constrained the plasma plume to near one dimensional expansion in the vertical plane. The effects of lateral spatial confinement on the expansion velocity of the LPP plume front, the temperature, density and expansion velocity of ions, enhancement of ion flux, and ion energy distribution were recorded. The periodic behavior of ion signals was analyzed and found to be related to the electron plasma frequency and electron-ion collision frequency. The effects of confinement and enhancement of various ion parameters and expansion velocities of the LPP ion plume are explained on the basis of shock wave theory.

• OSTI ID: 22303444
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 9 Vol. 21; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALUMINIUM
ELECTRON-ION COLLISIONS
ENERGY SPECTRA
ION DENSITY
IONS
LANGMUIR FREQUENCY
LANGMUIR PROBE
LASER-PRODUCED PLASMA
LASERS
OSCILLATIONS
PERIODICITY
PLASMA CONFINEMENT
PLASMA EXPANSION