  The electron density is one of the crucial parameters in plasma plume, which
plays a major role in producing the key reactive species required for
biological and industrial applications. In this work, experiments are performed
to estimate the spatial variation of plasma density in a steady plume. The
time-resolved images obtained from the ICCD camera, plume current measurements
are utilized for estimating the plasma density. We observed the plasma density
increases from the glass nozzle to the plume tip. This increase in plasma
density is due to the combined effect of reduction of drift velocity, charge,
and area confinement of plume. Further, the intensity plots of the ICCD camera
images obtained with larger exposure time validate the increased density at the
plume tip. The plasma density along the plume gives information about the
approximation to the plume exposure time desired and the impact it creates on
the very sensitive targets. The spatial variation of plasma density in a plume
is a futuristic requirement for several biological and industrial applications
considering a single plasma device.
