J. Oberling, J. Warner

After letting things settle overnight we took another look at the WHAM1 ISI alignment this morning.  Jim found that a few of the HEPI stops had become engaged (likely during the final moves yesterday afternoon), so he backed those off and I took a look at ISI alignment.  Again, the ISI position is reported as deviation from its nominal LHO global coordinates of [-22726.7, 0.0, -201.9] mm.

• X axis: +0.95 mm
• Y axis: +0.3 mm
• Z axis: +0.36 mm
• Yaw: ~144 µrad CCW
• Level to within 0.75 mm

Jim said this was good enough to begin attaching HEPI actuators, so that work has begun.  We'll take another look at ISI alignment once the actuators are attached.

Data

Data for the above alignment deviations.  Method described in alog 84057.

X axis position and yaw:

• +Y scale reading: +0.8 mm
• -Y scale reading: +1.1 mm
• X axis position: (1.1 + 0.8) / 2 = +0.95 mm
• Yaw: (1.1 - 0.8) / 2082.8 = +144 µrad => 144 µrad CCW

Y axis position:

• Total Station EDM: 2009.6 mm
• Target: 2009.3 mm
• Deviation: +0.3 mm

Z axis position and level:

• -X/+Y: 3.91"
• -X/-Y: 3.92"
• +X/+Y: 3.935"
• +X/-Y: 3.94"
• Average: 3.926"
• Target: 3.94"
• Deviation: +0.014" => +0.36 mm
• Level: 3.94 - 3.91 = 0.03" => 0.75 mm