  The emission angle distribution of projectile fragments (PFs) and the
temperature of PFs emission source for fragmentation of $^{56}$Fe on
polyethylene, carbon and aluminum targets at the highest energy of 496 A MeV
are investigated using CR-39 plastic nuclear track detector. It is found that
the averaged emission angle of PFs increases with the decrease of PF charge for
the same target, and no obvious dependence of angular distribution on the mass
of target nucleus is found for the same PF. The cumulated squared transverse
momentum distribution of PF can be well represented by a single Rayleigh
distribution, the temperature of PFs emission source is extracted from the
distribution, which is about 1.0-8.0 MeV and do not depend on the mass of
target for PF with charge of 9<=Z<=25.

Nuclear Experiment