Determination of the particle
momentum
Charged particles are deviated in a magnetic field. The larger the
momentum, the smaller the deviation. By measuring this deviation the momentum
can be determined. The track detectors are therefore often placed in a strong
magnetic field. In DELPHI the magnetic field is created by a supraconducting
solenoid. The magnetic field inside the solenoid is parallel to the beam line
of the colliding particles and its strength is 1.2 Tesla.