We summarize additions to our data base of charge-changing cross
sections for relativistic ultraheavy nuclei interacting in targets ranging
from H to Pb. We have improved parametric fits to those cross sections
as functions of energy and of projectile, target, and fragment charge. At
high energies, we have determined cross sections for Au projectiles at 10.6
GeV /nucleon in targets of H, CH_2, C, Al, Cu, Sn, and Pb. Compared
with cross sections at 1 GeV /n, fragment production is substantially
changed, especially for the H target. These changes have important implications
for calculations of interstellar propagation of ultraheavy nuclei.
At lower energies, we have added Kr and Ag to our list of projectiles.
Analysis of these data has led to a better understanding of the systematics
of these cross sections, hence more physically meaningful parameterizations
for fragmentation at high energies and for charge pickup
