Timing below 100 ps with Spark Counters: Work principle and applications

The work principle of a spark counter with a localized discharge is described. A review of main counter characteristics as well as the key points of the latest R&D on the counter are presented. Possible large scale spark counter applications for the investigation of ion-ion collisions are discussed: ALICE - a dedicaated heavy-ion experiment at the CERN Large Collider (LHC); the FOPI-Detector at the SIS accelerator of GSI, Darmstadt; NA49 - a fixed target experiment at the CERN-SPS