  Using an isospin-dependent quantum molecular dynamics, nuclear stopping in
intermediate heavy ion collisions has been studied. The calculation has been
done for colliding systems with different neutron-proton ratios in beam energy
ranging from 15MeV/u to 150MeV/u. It is found that, in the energy region from
above Fermi energy to 150MeV/u, nuclear stopping is very sensitive to the
isospin dependence of in-medium nucleon-nucleon cross section, but insensitive
to symmetry potential. From this investigation, we propose that nuclear
stopping can be used as a new probe to extract the information on the isospin
dependence of in-medium nucleon-nucleon cross section in intermediate energy
heavy ion collisions.
