Effects of a steady magnetic field on the laser-induced breakdown spectroscopy of certain elements (Mn, Mg, Cr, and Ti) in aqueous solution were studied, in which the plasma plume expanded across an external steady magnetic field (∼5 kilogauss). Nearly 1.5 times enhancement in the line emission intensity was observed in the presence of the magnetic field. The temporal evolution of the line emission showed a significant enhancement in plasma emission between 2- and 7-μs gate delays for Mg in the presence of the magnetic field (5–30 μs for Mn). This enhancement in the emission is attributed to an increase in the rate of recombination because of an increase in plasma density due to a magnetic confinement after cooling the plasma. The increase in the optical line emission due to magnetic confinement was absent when the plasma was hot with a dominant background (continuum) emission. The limits of detection of Mg and Mn were reduced by a factor of two in the presence of a steady magnetic field of 5 kilogauss.
© 2003 Optical Society of America
(120.6200) Instrumentation, measurement, and metrology : Spectrometers and spectroscopic instrumentation
(140.3440) Lasers and laser optics : Laser-induced breakdown
(300.2140) Spectroscopy : Emission
(300.6210) Spectroscopy : Spectroscopy, atomic
(300.6360) Spectroscopy : Spectroscopy, laser
Virendra N. Rai, Hansheng Zhang, Fang Y. Yueh, Jagdish P. Singh, and Akshaya Kumar, "Effect of Steady Magnetic Field on Laser-Induced Breakdown Spectroscopy," Appl. Opt. 42, 3662-3669 (2003)