Spectroscopic study of magnetically-confined laser induced aluminium plasma

The characteristics of laser-induced Al plasmas under the confinement of a magnetic field with different pressures and laser fluences have been investigated using an optical multichannel analyzer (OMA). A magnetic field up to 0.26 Tesla was produced by two permanent magnets. A KrF excimer laser with a wavelength of 248 nm and a pulse width of 23 ns was used to produce plasmas which expanded across the magnetic field. The spectral intensity evolution of different Al spectral lines as functions of delay times, air pressures and laser fluences were reported and the mechanisms behind the observations were analyzed. It was observed that the magnetic field had obvious effect on the Al plasma spectra.