  In the present work, we report the dynamics and geometrical features of the
plasma plume formed by the laser ablation of copper and graphite (carbon)
targets in the presence of different transverse magnetic field. This work
emphasizes on the effect of atomic mass of the plume species on the diamagnetic
behaviour and geometrical aspect of the expanding plasma plume in the magnetic
field. The time-resolved analysis of the simultaneously captured two
directional images in orthogonal to the expansion axis is carried out for the
comparative study of projected three-dimensional structure of copper and carbon
plasma plume. In the presence of magnetic field, sharp differences are observed
between the copper and carbon plasma plumes in terms of formation of
diamagnetic cavity and structure formation. An elliptical cavity-like structure
is observed in case of copper plasma plume which attains the sharp conical
shape with increasing the time delay or magnetic field strength. On the other
hand, splitted carbon plasma plume appears as a Y-shape structure in the
presence of magnetic field where the cavity-like structure is not observed for
the considered time and magnetic field. Based on the modified energy balance
relation for the elliptic cylindrical geometry, we have also simulated the
dynamics of the plume which is in close agreement with observed plasma
expansion in diamagnetic and non-diamagnetic regions.
