The magnetic excitations will be studied in a powdered sample of 3% CoO in 97% MgO in order to to study the excitations of isolated Co ions and of isolated pairs of Co ions. (MgO is non-magnetic.) The experiments will be performed using the MARI spectrometer with the sample cooled between temperatures of 295K and 5K. Measurements of the spin orbit interaction have been made by studying the excitation energy of isolated Co ions. The excitation energy is similar to the phonon density of states of MgO and so careful measurements are needed for both the mixed powder and for pure MgO. Measurements of the pair excitations provide information about J1 and J2 where J1 is the exchange interaction between nearest neighbours and J2 the exchange between next nearest neighbours. These measurements will require experiments at several different incident neutron energies and at various temperatures.