with Fabian-san, Hirata-san
For mirror cleaning, today we locked the suspension, set the jigs' bases, and inspected its surface.
We found some stain-like dirt on its HR side, which maybe couldn't be cleaned by FC,
and we also found some tiny dust on both sides of the mirror using green light.
It's difficult to find this dirt on our picture, but I uploaded today's pictures here.
I'll apply the First Contact on both sides of the mirror tomorrow.
with Hirata-san,
At first, we set the jig for HR and applied the First Contact on the HR side.
One drop of FC reached this jig on its left side, we removed this jig and repaired this area at the end.
After the HR side, we also applied on the AR side.
Our pictures were uploaded here.
We'll peel off these FC after cleaning inside the chamber tomorrow.
with Hirata-san, Yano-san, and Miyoki-san
At first, we cleaned outside and inside the chamber.
And then we peeled off both sides of the FC using a Top gun.
The center area seems clean mostly but there were still some dirt and dust that is on the out-of-jig range.
Unfortunately, FC residue remains on the HR right side, which we pulled the peeling tab(fig.1).
On the other hand, we successfully peeled off AR FC, but tragically I touched the surface of the AR mirror when we inspected it after peeling and made a new stain on its upper left(fig.2).
Both of them may affect the beam, we decided to try to remove them.
At first, we applied the FC on a partial area of the AR side(fig.3).
We'll remove this additional FC and inspect it again tomorrow morning.
Next, we pushed away the HR FC residue by using swab stick and Vectra alpha(fig.4).
This stain were divided and pushed to its edge direction but slightly spreded(fig.5).
NOTE;
1. DO NOT pointâ at remaining dirt after cleaning.
2. Before applying, check the beam path and put a peeling tab on the least affected area.
with Hirata-san, Miyoki-san
[AR]
We successfully removed the additional FC on the AR side and we could completely remove the stain(fig.1).
But we found some dirt or dust on its upper right, which couldn't be removed by blowing(fig.2).
Furthermore, it seems some dust stuck to its surface after the FC was removed, so please keep it clean!!
[HR]
We inspected the right side stain, which we had pushed away yesterday and decided re-apply the FC on this partial area(fig.3&4).
We prepared a dummy piece with the same amount of FC applied to see if it dried(fig.5).
After about 3 hour we confirmed FC was dried up using a dummy, and peeled off the FC on the mirror.
The stain we wanted to remove were completely removed, but FC edge, that was under the tab we pulled, remained again(fig.6).
Because this residue was much far from its center, we finished this cleaning work and released the suspension.
[PICTURES]
https://www.dropbox.com/work/Subsystems/MIR/mirror%20inspection/BS/20220527
