  Gas electron multipliers (GEM) detectors are gaseous detectors widely used
for tracking and imaging applications due to their good position resolution,
high efficiency at high irradiation rates, among other factors. In the present
work, position resolution, charge spread, energy resolution and gain uniformity
have been investigated experimentally for single and double GEM geometries
using an Fe-55 source. The position resolution measurements have been performed
by a novel method, using a high precision instrument for source movement and is
found to be highly successful. The result shows that the double GEM can resolve
positions with sigma values up to 36.8 micron and 54.6 micron in x and y
directions, respectively. To validate the experimental results, a Garfield
simulation work has been carried out on charge spread.
