Effect of magnetic field confinement on LIBS spectral enhancement and shape

In order to enhance the emission spectrum of plasma in laser induced breakdown spectroscopy (LIBS), magnetic fields with different intensities were applied around the plasma to investigate its enhancement. Adjust the laser energy to 60mJ, change the magnetic field strength, use the traditional LIBS, magnetic field enhanced LIBS (MF-LIBS) for laser-induced breakdown of pure copper samples, to obtain the spectral comparison of characteristic line of trace elements (Bi I 206.16 nm) under different constraints and analysis of its enhancement mechanism. The experimental results show that the magnetic field of 153mT will reduce the spectral intensity, the 20mT, 50mT, and 90mT magnetic fields will enhance the spectral intensity. The stronger the magnetic field, the better the spectral enhancement effect, but the enhancement effect of 20mt is not obvious. The Lorenz fitting coefficient of the line is the lowest when magnetic field is not applied, the fitting coefficient gradually increases at 153mT, 20mT, 50mT and 90mT magnetic fields, indicating that the line shape is closer to the Lorentz type. And the spectral line width are also larger and reaches the largest when the 90 mT magnetic field is applied.