We shook the PSL table and all chambers at the corner station except ITMY individually. By far the greatest up-conversion was at the BS. The figure shows that even a 20% increase in 1-80 Hz GS13 BLRMS produces bumps at higher frequencies. The up-conversion from injected peaks is not broadband like magnet domain changing noise, and is not a harmonic series like from scattering or saturation, but, instead produces peaks that look like intermodulation products.

Robert, Jordan