[Ikeda, Fabian, Hirata, Yasui, Ushiba]

Abstract:
After the recovery of PRM traverser, we roughly aligned the PRM so that reflection beam comes back to IFI.
Then, we send IR beam and checked the beam position at PRM and PR2.

Detail:
After the PRM traverser recovery (klog19319), we roughly algined PRM so that HR reflection is overlaped with the injection beam.
First, we locked the suspension to the flame to avoid shaking suspension too much by moving the traverser a lot.
Then, we released suspension and aligned PRM by the traverser and picomotor while checking the reflection beam position at several place: in front of PRM, IMMT2, and IFI.
We rotated the traverser by 1260 mdegs to +YAW direction (reverse direction of the traverser) to align the PRM while I'm not sure how much the picomotor moved.
After the alignment, reflection beam is coming back to at least around IFI.

Then, we checked the PR2 target plate position with respect to the PR2 recoil mass center.
We set the laser leveler on the reference point on the ground in front of PR2 and align vertical laser line to PR2 recoil mass center (fig1).
Then, we put target in front of PR2 and found the marker is slightly off from the center (fig2).
So, we realigned the target slightly (fig3).

Then, we checked the greenX beam position on the target (fig4), which is hitting almost center of the target.
After that, we moved IMMT2 to hit main IR beam around PR2 center (fig5) and then checked the IR beam position on the PRM target (fig6).

Note:
Currently, if we made PRM-PR2 line by using reference at the ground and PR2 center(fig6), the laser line at PRM is 2cm off from the PRM cenmter (fig7).
In addition, if we made PRM-PR2 line by using reference at the ground and PRM center(fig8), ther laser line at PR2 is 1-2 mm off from the PR2 center (fig9).
So, it is better to set the reference of PRM-PR2 line again in the same way in klog19157.