  The physics motivation for a very forward detector for the ALICE heavy ion
experiment at the CERN LHC is discussed. A phenomenological model describing
the formation and decay of a Centauro fireball in nucleus-nucleus collisions is
presented. The CASTOR detector which is aimed to measure the hadronic and
photonic content of an interaction and to identify deeply penetrating objects
in the very forward, baryon-rich phase space 5.6 < eta < 7.2 in an
event-by-event mode is described. Results of simulations of the expected
response of the calorimeter, and in particular to the passage of strangelets,
are presented.
