We propose to measure possible exciton states below the anisotropy gap in CaFe2O4. Recent diffraction work by ourselves has shown that this structure has two competing magnetic phases allowing antiphase boundaries to be energetically favourable and also controllable with a magnetic field. In our previous study, we observe significant scattering peak at 1 meV, within the gap of the 1-magnon fluctuations. We propose to map these out in this experiment using the good resolution on OSIRIS. The experiment requests 6 days of time.