LASER INDUCED BREAKDOWN SPECTROSCOPY OF LIQUID AND SOLID SAMPLES IN THE PRESENCE OF MAGNETIC FIELD

Abstract

Investigation of optical emission from laser-produced plasma expanding across an external magnetic field is the subject of current interest and has its application in various field of research[1-2]. It is well known that various external parameters such as energy and wavelength of the laser, electric and magnetic field, and ambient condition, affects the plasma parameters and emission properties. The effects of magnetic field on the emission properties of laser-produced plasma have been studied earlier [1-2]. During the process of plasma expansion (deceleration in the presence of magnetic field), the kinetic energy of the plasma is totally transformed into thermal energy of the plasma as well as in the energy of the magnetic field. In this situation, the plasmas emission as well as its various other physical properties change. Effect of magnetic field on the emission from the laser-produced plasma has been studied by many authors from X-ray to visible wavelength range at different experimental conditions. Laser Induced Breakdown Spectroscopy (LIBS) is a laser based diagnostics technique, which has been used to study the atomic emission from various samples such as solid, liquid or gas [3]. In the light of the above discussion, it will be interesting to study the effect of a low intensity steady magnetic field on the LIBS signal from liquid as well as solid samples, which will be important for trace element analysis. In the present experiment we have studied the emission properties of the laser-produced plasma from the metal seeded liquid samples as well as aluminum alloy in the presence of magnetic field.