Spatial and temporal evolution of electron density and plasma potential by resonance hairpin probe and emissive probe during pulsed laser photo-detachment of negative ions

ORAL

Abstract

Laser~photo-detachment is the most commonly used technique for measuring negative ion parameters. In this study we measured the electron density perturbation using a resonance hairpin probe and plasma potential using floating emissive probe along the path and outside the laser beam. Experiment is performed in a 13.56 MHz inductive RF discharge for various ranges of power and pressures. It is found that the plasma potential rises instantaneously for confining the photo-detached electrons and decays at a rate dictated by the diffusion of negative ions from the adjacent layer. This is found to be consistent with the spatial and temporal evolution of electron density.

–

Authors

  • N. Sirse

    National Centre For Plasma Science and Technology, Dublin City University, Ireland

  • M.A. Mujawar

    National Centre For Plasma Science and Technology, Dublin City University, Ireland, NCPST, Dublin City University, Dublin 9, Ireland

  • Jim Conway

    National Centre For Plasma Science and Technology, Dublin City University, Ireland, Dublin City University

  • Miles Turner

    Dublin City University, Dublin City University, Ireland, National Centre For Plasma Science and Technology, Dublin City University, Ireland, NCPST, Dublin City University, Dublin 9, Ireland, NCPST, School of Physical Sciences, DCU, NCPST, DCU

  • S.K. Karkari

    Dublin City University, Ireland and Institute for Plasma Research, India, National Centre for Plasma Science and Technology, Dublin City University, Ireland and Institute for Plasma Research, Bhat, Gandhinagar, India, NCPST, Dublin City University, Dublin 9, Ireland \& Institute for Plasma Research, Bhat, Gandhinagar, Gujarat, India, 382428, National Centre For Plasma Science and Technology, Dublin City University, Ireland and Institute For Plasma Research, Bhat, Ghandhinagar, India