M. Barton, (J. Kissel)

After the IAS/SUS team performed the final tweaks on H1SUSITMY, Mark (late last night!) remeasured each chain's TOP to TOP transfer functions. I attach the processed results. Baring noise arising from the in-air measurement, the mechanics look as good as they did at-vacuum in chamber, back in late May. In fact, it appears as though the alignment tweaks had little to know affect on the dynamics. Nice work all!

I approve this QUAD for re-re-re-installation. (Don't worry, we've still got one more!)

Interesting note (which is of no consequence but academic): this QUAD's Thin CP has been flipped, as per E1200943. Because we've assembled the TCP and ERM prisms to have a physical d4 of 0 mm (i.e. the prism break off is "exactly" ([+/- 1 [mm]) parallel to the optic's horizontal centerline, see T1200487), the dynamics should not have changed after flipping the TCP. However, as can be seen on pg 11 (R0 P to P) of allquads_121115_H1SUSITMY_Phase2a_ALL_ZOOMED_TFs.pdf, the (poorly modeled) P/L mode that was (measured) formerly at 0.74 Hz has moved up to 0.77 Hz. This mode is known to vary almost entirely due to changes in effective d4 ( = physical d4 + flexure correction). Assuming that the flexure correction (dependent on wire parameters and the tension on them from the optic mass) has not changed substantially (if at all), this implies that the physical d has changed with the flip, further implying that indeed the prisms are not bonded exactly along the optic centerline, but slightly below the center line (where "below" is defined by its original orientation, yet presumably still within the +/- 1 [mm] tolerance). That pitch is too sensitive, I tell you!