[Jenne, Koji and Kiwamu]
We finished a coarse alignment of IP_ANG.
The beam for IP_ANG successfully reached to the ETMY chamber and is ready for the final alignment.
(Additionally we again tried looking for a resonance for TEM00 in the X arm, but we obtained only flashes of some higher order modes.)
--- what we did
* installed the steering mirrors for IP_ANG and IP_POS.
* checked PZT1 if it worked correctly or not. It was healthy.
* neutralized and realigned PZT1.
* flipped a window, which is standing before PRM, because the wedged side of the window was at wrong side.
* realigned PZT2 and checked the spot positions on the TTs.
* repositioned more carefully the TTs and aligned them to the correct angles.
* aligned the beam to the center of both the BS and ITMY by rotating the last TT.
* aligned the beam more precisely by tweaking PZT2 while looking at the spot at the Y end.
The beam is still hitting the center of ETMY.
* aligned the steering mirror for IP_ANG while looking at the spot at the Y end.
In fact IP_ANG is visible with a card.
* aligned the BS by looking at the spot on ITMX.
* covered ETMX with aluminum foil, and made a ~1cm hole on the foil as a target.
The hole was placed on the center of ETMX.
* more precisely aligned the BS by looking at the spot on the aluminum foil.
The spot was clearly visible on CCD monitor.
* aligned the ITMX by looking at a spot on the foil. The spot represented the beam reflected by ITMX back to ETMX.
* saw flashes on the foil but couldn't make it TEM00 because it was difficult to see any flashes on the surface of either ETMX or ITMX.
It means the flashes are visible only when the beam is hitting some scattering surface.
The mirror surface of the test masses are less lossy than that of the old test masses ??