Fission Cross Sections of Lead Projectiles in Pb-Nucleus Interactions at 40 and 158 Gev/C Per Nucleon

The fission of lead projectiles has been investigated at the CERN SPS by the NA50 experiment. For this study, a Cherenkov quartz detector was added to the standard NA50 setup to measure the charge of projectilelike fragments. The data collected on different targets at 40 and 158 GeV/c per nucleon are presented here. The contributions arising from the nuclear and the electromagnetic fission mechanism are extracted from the measured fission cross sections; the electromagnetic contribution is then compared to the Weizsacker-Williams predictions.