We propose to map out the spin excitations in La2O2FeOSe2 using the MARI chopper spectrometer on a powder sample. Although the structure of La2O2FeOSe2 has some similarities to the iron based superconductors, this compound is not metallic and there is considerable evidence suggesting it is a Mott insulator. We have obtained some data already on DCS for energies below 10 meV and apply to use MARI to map out the entire dispersion. The proposal calls for 5 days.