  We report the measurement of the fragmentation cross sections in high-energy
nucleus-nucleus collisions using the 158 A GeV Pb beam from the CERN-SPS. The
fragments have charges changed from that of the incident projectile nucleus by
$\Delta Z=Z_{Pb}-Z_{frag}$, with 8 <\Delta Z <75. The targets range from
polyethylene to lead. Charge identification is made with CR39 nuclear track
detectors, measured with an automatic image analyzer system. The measured
fragmentation cross sections are parameterized with an empirical relation in
terms of the atomic mass of the target, and of the charge of the final
fragment.
