Forward Multiplicity Detector
The Forward Multiplicity Detector (FMD) has a special role in ALICE. It is designed to measure the charged particles produced in the collisions and emitted at small angles relative to the beam direction. The FMD also provides an independent measurement of the orientation of the collisions in the vertical plane, which can be used with measurements from the barrel detector to investigate flow, jets, etc. It is the primary detector to measure the multiplicity distribution of charged particles over a wide kinematical range (rapidity coverage in the interval 1.7 < |η| < 5.1 corresponding to an angular interval of about 0.75 degrees to 21 degrees with respect to the beam direction.