Studies of the Electromagnetic Calorimeter and Direct Photon Production at the CMS Detector

This thesis describes the work I have undertaken as a member of the CMS collaboration. I have been working on the test beam programme for the Electromagnetic calorimeter and also studying direct photon production. The CMS collaboration is composed of 145 institutions from 30 countries, with a total membership of more than 1700 scientists who are all working towards the construction of a general purpose detector for the Large Hadron Collider (LHC). The LHC 7 TeV proton-proton collider is to be built at CERN, the European Centre for Particle Physics where it will replace the existing LEP collider. The project is currently (Spring 1999) in the final design and testing stages and it is expected that construction will be complete and data taking will begin in the year 2005.