Influence of axial magnetic field on angular distribution of charge and energy of laser produced slow and fast tungsten ion groups

Here effect of magnetic field on the angular distribution of laser produced tungsten (W) ions is reported. Plasma plume was generated by irradiating surface of W target, placed inside a vacuum chamber under magnetic field of 0.23 T, by nanosecond pulsed laser beam. Angular distribution of W ion flux was measured with the help of an ion collector (IC) and explained under the framework of Anisimov model. Magnetic field clearly split the ion signals temporally into comparable fast and slow ion components and enhanced the intensity of fast ion group significantly. Enhancement of ion charge state with B was confirmed by Ion energy analyser (IEA). Theoretical fitting of bimodal ion signal suggested the existence of thermal and non-thermal component of nanosecond laser produced plasma. With magnetic field, a two fold increase in total charge of the fast ion component was observed. Magnetic field effect on ion energy was also investigated. The optical emission spectrum of W plasma was also recorded, and plasma parameters were measured in both the absence and presence of magnetic field. The rise of electron temperature and number density in presence of B confirmed the heating of W plasma by magnetic field.

Automated summary

The effects of magnetic field on the angular distribution of laser produced tungsten ions were investigated. A plasma plume was generated by irradiating the surface of a tungsten target with a nanosecond pulsed laser beam inside a vacuum chamber under a magnetic field of 0.23 T. The angular distribution of the tungsten ion flux was measured and explained using the Anisimov model. The magnetic field caused a temporal splitting of the ion signals into fast and slow ion components, enhancing the intensity of the fast ion group significantly.