  A prototype Gas Electron Multiplier (GEM) detector is under construction for
medical imaging purposes. A single thick GEM of size 10x10 cm^2 is assembled
inside a square shaped air-tight box which is made of Perspex glass. In order
to ionize gas inside the drift field two types of voltage supplier circuits
were fabricated, and array of 2x4 pads of each size 4x8 mm^2 were utilized for
collecting avalanche charges. Preliminary testing results show that the circuit
which produces high voltage and low current is better than that of low voltage
and high current supplier circuit in terms of x-ray signal counting rates.
