Performance of the HERMES micro-strip gas chamber for the HERMES collaboration

A large Micro-Strip Gas Counter (MSGC) is in use at the HERMES deep-inelastic lepton scattering experiment at DESY for the determination of the interaction vertex. This chamber consists of two separate units, one above and one below the beam line. Each detector half comprises six planes with an active area of 13 × 40 cm2 each. To minimize the data transfer time, the signals of the 24 800 anode strips are digitized at an early stage, resulting in a deadtime of less than 58 μs. The performance during the 1996 and (part of) 1997 running period is described.