Yano, Hirata, Akutsu + Miyo; Cont'd from 17595 and 17635.
Abstract
Two things. 1. check if the GreenX go-back could get back, and it was recovered. 2. Height re-measuremnt. The 2nd point will be reported by Hirata-san later.
Details
First of all, we would like to confirm that the GreenX can be recovered with the PR2 suspneded table when the pair of the mid-size baffles was dismontled. GreenX was lost, and Miyo-kun swept PR3, and finally found a new nice combination of the PR3 good oplev. Although there was an accident of PR3 jump (see 17617), we thought the variation of the good oplev values would occur due to the PR2 suspended table movement.... note that PR3 would come back to its good oplev value even after the jump incident.
Fig. 1 shows several relevant signals at the time around we recovered GreenX optical path. The point is that the PR3 oplev values (the 3rd and 4th panes). In those days, (P,Y)=(0,0) was the set point for good alignment, but now, even though the condition of the PR2 suspended table is the same (i,e, no mid-size baffles), the updated good oplev is (P,Y) = (-3, 127.5) urad. So pitch has not varied so much, while yaw much!! Note that these values are not necessarily the drift of PR3; rather, considering what we were doing, these variation would occur due to the loading on and off the PR2 suspended table.
Discussion
Looking back the past, Fig. 2 is the situation at the time when we fisrtly put the pair of the PR2 mid-size baffles and released the suspeneded table. As written in 17595, we lost GreenX at that time and did search and recovered. At this time, (P, Y) =(0,0) should be the good oplev in the past, but after loading the PR2 suspended table with the mid-size baffles, to compensate the mis-alignment of the GreenX optical path, PR3 set point should change to (P, Y) = (0.3, -33). Comparing the numbers as of today,
- pitch seems stable.
- yaw seems easily moved... the direction (signal sign) seems opposite along with loaded or unloaded. But of course we lack enough statistics.
