Calorimeter

The calorimeter in the ZEUS detector surrounds the tracking detector. It absorbs and measures the energy of the particles incident on it. It is made of layers of depleted uranium and scintilator. Depleted uranium is used because it is very dense and so is good at absorbing particles. The scintillator between the layers of depleted uranium produces small flashes of light when particles are absorbed which are then amplified using photo-multiplier tubes and go on to produce a signal.

This is a picture of the entire calorimeter with the yokes and muon detectors (which lie outside of the calorimeter) retracted.