I recently reported on multiple potential stray light issues in the vertex area, including a 45 degree conical annular beam from the beamsplitter, and a reflection of the halo of the beam passing through the ITMX elliptical baffle that is roughly directed at ITMY (83050). In a first attempt to study potential scattered light noise problems from these beams, before the break I injected 0.2 Hz X and Y motion onto the BS HEPI, with motion amplitudes of about 1e-6 m at stages, 0 and 2 (see figure).  The figure demonstrates with spectrograms and spectra (second page), that there is a slight increase in DARM noise for both X and Y injections,  mainly below 60 Hz. I turned the injections on and off multiple times because the noise is pretty subtle. I think we should further study these potential scattering issues after the break.