A Study of Electromagnetic Showers in the High Density Projection Chamber

A prototype module of a High density Projection Chamber (HPC) has been tested in an electron beam. The HPC, with the shower conversion separated from the charge collection, offers a simple, homogeneous large volume detector with an energy resolution of 12.5%/?E and an exceptionally fine granularity both along and transverse to the shower axis. The results from the test are presented together with a description of the calorimeter system.