J. Kissel

I've gathered full sets of close out transfer functions for H1SUSPR3 (and HLTS) and H1SUSITMX (a wire-suspended QUAD). The results look good enough to proceed with pump down!

Yellow Flags:
H1SUSPR3 -- The Q of the 1st first vertical mode appears to be reduced from previous measurements of the free in-air suspension. I attach the .pdf of the raw DTT results for this DOF as well, to show that the coherence is still good for this resonance, implying a real loss mechanism. This is also noticeable on the R and T degrees of freedom as well, again only on the first resonance. But all resonant frequencies are in the same place, so the dynamics are as expected and well-behaved. In the end, we want these modes damped anyways, right? However if it is a real source of loss, then it's a source of noise. However, given that these are all the lowest frequency resonance, and it's the V/R DOFs it means that the loss is most likely on the top blade springs -- well away from the optic, so what ever excess noise is present will be filtered by the otherwise free SUS.

H1SUSITMX -- The only thing awry here is that the R0 V and R DOFs show much higher response (an overall DC scale factor) than expected. However, it was immediately obvious that this is a result of calibration filters not turned on. Taking a look, we immediately discovered this to be the case -- the "to_um" filters has been turned off for ONLY the R0 LF and RT OSEMs. They're now turned on, and we will be sure to capture a new safe.snap so this problem doesn't arise again.


All data and common scripts (with updated meas:ists) are committed to the SusSVN as of this entry.