First target name: FO Aquarii Proposal number: 6507 Category: 3 (cataclysmic variables) PI number: 7004 Abstract: We shall investigate the white dwarf spin and beat pulse profiles of the intermediate polar, FO Aqr. In a 20ksec observation with the HRI, a complete orbital cycle of the system and 16 spin cycles of the white dwarf will be seen. Using the 1-D CLEAN algorithm, profiles will be reconstructed directly from the power spectrum, resulting in lightcurves which are uncontaminated by other source periods or window function effects. By combining these data with our earlier GINGA pulse profiles, we shall model the accretion mechanism of the system using our recently developed intermediate polar lightcurve modelling code. We shall thus determine the size, shape and location of the white dwarf emission regions and the fraction of the accretion flow which does and does not pass through a disc.