Time of flight mass measurements in the neutron rich Fe region.

Masses of neutron rich nuclei are of high importance for astrophysics. They are direct inputs for r-process calculations, for modelling nuclear reactions in the crust of accreting neutron stars, etc. For most of the nuclides involved in these processes, the mass has not been determined experimentally. We have recently performed mass measurements by the time of flight technique at the National Superconducting Cyclotron Laboratory at Michigan State University. Details of the experimental technique are discussed, together with the first experiment in the neutron rich Fe region.