Optical emission enhancement of laser-produced copper plasma under a steady magnetic field

From a copper target, laser-ablated plasma was investigated by spectral- and temporal-resolved emission spectroscopy. With the presence of a 0.8T steady magnetic field, the emission of the expanding plasma showed significant enhancements of the spectral lines for all neutral, singly, and doubly ionized species. The relative enhancements for different species have been studied with temporal-resolved measurement by comparing the spectra obtained with and without the magnetic field. The enhanced emission from the plasma plume is attributed to an increase of the radiative recombination rate in the plasma due to magnetic confinement. The temporal evolution of the plasma parameters, including electron temperature and electron density, was deduced and discussed for the cases with and without a magnetic field. (C) 2008 Optical Society of America