We finished the installation of ETMX into the chamber.
In order to clear the issue of the side OSEM, we put a spacer such that the OSEM can tilt itself and accommodate the magnet.
Though we still don't fully understand why the side magnet is off from the center.
Anyway we are going to proceed with this ETMX and perform the REAL green locking.
(what we did)
- took the ETM tower out from the chamber, and brought it to the clean room again.
- checked the rotation of the ETM by using a microscope. It was pretty good.
The scribe lines at the both sides are at the same height within the diameter of the scribe line.
- checked the height of the ETM by measuring the vertical distance from the table top to the scribe line. This was also quite good.
The height is correctly 5.5 inch within the diameter of the scribe line.
- checked the magnet positions compared with the OSEM holder holes.
All the face magnets are a little bit off upward (approximately by 1mm or less).
The side magnet is off toward the AR surface by ~ 1-2mm.
(yesterday we thought it was off downward, but actually the height is good.)
- raised the position of the OSEM holder bar in order to correct the miscentering of the face magnets.
Now all the face magnets are well centered.
- brought the tower back to the chamber again
- installed the OSEMs
We put a folded piece of aluminum foil in between the hole and the side OSEM as a spacer.
- leveled the table and set the OSEMs to their mid positions.
- slided the tower to place