Optik - International Journal for Light and Electron Optics 224 (2020) 165746 Available online 6 October 2020 0030-4026/© 2020 Elsevier GmbH. All rights reserved. Original research article Enhancement of optical signal and characterization of palladium plasma by magnetic field-assisted laser-induced breakdown spectroscopy Shahab Ahmed Abbasi a, *, Zaheer Aziz a , Taj Muhammad Khan b , Dilawar Ali c , Toqeer ul Hassan a , Javed Iqbal a , Salah Ud-Din Khan d , Ashfaq Ahmad e, **, Rawaiz Khan f , Eid Muhammad Khan g a Department of Physics, University of Azad Jammu and Kashmir, Muzaffarabad, 13100, Pakistan b National Institute of Lasers and Optronics (NILOP), P.O. Nilore, 45650, Islamabad, Pakistan c Department of Physics, Government College University, Lahore, 54000, Pakistan d Sustainable Energy Technologies Center, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia e Department of Chemistry, College of Science, King Saud University, Riyadh, 2455, Riyadh 11451, Saudi Arabia f Engineer Abdullah Bugshan Research Chair for Dental and Oral Rehabilitation, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia g Acarology Laboratory, Department of Plant Protection, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia A R T I C L E INFO Keywords: MF-LIBS Palladium Magnetic field Intensity enhancement MHD ABSTRACT Optical emission signal enhancement from palladium (Pd) plasma by magnetic field-assisted laser-induced breakdown spectroscopy (MF-LIBS) is reported. Plasma from Pd target was pro- duced by second harmonic generation (532 nm, 5 ns) of Nd:YAG laser using fluence values in the range of 12.6–38.1 J/cm 2 . In the designed experiment, the magnetic field was parallel to the axis of plasma expansion direction with a maximum strength of 0.12 T at the target surface. Optical signals of the emission from the plasma were recorded in the spectral range of 200 700 nm with a LIBS2000+ spectrometer. A significant enhancement was noticed particularly at low fluence values for both atomic and singly ionized Pd lines. For the minimum fluence 12.6 J/cm 2 , an intensity enhancement of 3–4 fold was observed for Pd-I and Pd-II lines and dropped exponen- tially for the increased fluence values. At low fluence values, the trace elements viz., Ca and Mg were detected only in the presence of magnetic field. The optical signal enhancement effect of magnetic field was different for Pd, Ca, Mg, and H; suggesting that the field enhanced effect is strictly element dependent for plasma at the same conditions. The field influenced the plasma parameters; the electron number density (n e ), and temperature (T) which were increased considerably compared to without field. Expectedly, these attributes come from the plasma confinement by the external magnetic field and have been explained in the framework of magneto hydrodynamic (MHD) model. * Corresponding author at: Department of Physics, University of Azad Jammu and Kashmir, Muzaffarabad, 13100, Azad Jammu & Kashmir, Pakistan. ** Corresponding author at: Department of Chemistry, College of Science, King Saud University, Riyadh, 2455, Riyadh 11451, Saudi Arabia. E-mail addresses: shahab.ahmed@ajku.edu.pk (S.A. Abbasi), aahmad1@KSU.EDU.SA (A. Ahmad). Contents lists available at ScienceDirect Optik journal homepage: www.elsevier.com/locate/ijleo https://doi.org/10.1016/j.ijleo.2020.165746 Received 11 July 2020; Received in revised form 17 September 2020; Accepted 30 September 2020