Calorimeters
The energy of both charged and neutral particles can be measured with
calorimeters. A calorimeter consists of several layers of a heavy material
like lead or iron interleaved with layers of gas. The particle interacts in the
heavy material giving rise to a shower of particles. The total number of
particles produced is proportional to the energy of the original particle. The
ionisation in the gas volumes between the heavy material measures the number of
produced particles. The ionisation is collected on metal wires or pads as in
the track detector.