  The J/\Psi(1S) and \Psi'(2S) production near threshold in antiproton-nucleus
reactions is calculated on the basis of the Glauber model. The model takes into
account the antiproton (pre)absorption, proton Fermi motion, and charmonium
formation length. We confirm earlier prediction that the charmonium production
in $\bar pA$ collisions at $p_{lab}=3-10$ GeV/c is not influenced by formation
length effects and is very well suited to determine the genuine
charmonium-nucleon dissociation cross sections. The comparison is performed
with the J/\Psi photoproduction at high energies, where formation length
effects play a very important role. However, we demonstrate that the detailed
structure of the proton and neutron density profiles has to be taken into
account, if one wants to extract information on the J/\Psi N dissociation cross
section from J/\Psi transparency ratios. These studies are relevant for the
upcoming PANDA experiment at FAIR.
