Time-resolved HST UV echelle spectroscopy of IX Vel

In the hydrodynamical line-driven disk wind models of Proga, Stone & Drew (1998) the mass loss rate is a strong function of the local luminosity. Also, the outflow is found to be subject to clumping, where the main source of driving radiation is the accretion disk. In order to test these predictions, we have obtained high resolution UV spectroscopy of the brightest novalike variable, IX Vel. These data have allowed us to examine the line profile structure in unprecedented detail.