Magnetic field enhanced growth of carbon cluster ions in the laser ablation plume of graphite

Time-of-flight mass spectrometric studies were carried out on neutral and positive ion clusters, composed of up to twenty carbon atoms, produced by Nd:YAG laser ablation of graphite in the presence of magnetic fields in the range of 0.03–0.10 T. The growth of larger carbon cluster ions with C11+ dominance in the laser-ionized ablation plume of graphite was found to be enhanced by the magnetic fieds. We believe that an enhancement of ion-neutral reactions due to an increase of ionic species, resulting from collisional ionization of neutral species through a confinement of electrons, leads to the growth of larger carbon cluster ions.