ABSTRACT
The detector surrounding the production location had full coverage in solid angle so that the energy and momenta of all the produced particles except the neutrino were measured. The earliest detectors depended on direct optical observations. A commonly used track detector is the spark chamber. It consists of a number of parallel metal plates mounted in a region filled with a mixture of gases, helium and neon. The detector is large enough in size that all the energy is deposited in the detector. One feature of the shower detectors which can be useful for identification of the particle as an electron or hadron is based on the different lateral and longitudinal shapes that form as the showers develop. The interactions of electrons and positrons occur in the middle of the detector. The tracking detectors detect the ionization caused by the outgoing charged particle.
