Marc, Michael, Abe, Aso
Unfortunately, the Onsen treatment of ETMY did not remove the stains.
So, we decided to move on to the absorption measurement.
First contact cleaning
Before moving the mirror, we decided to clean the surface, for the first time after the contamination, with first contact.
Surface inspection after FC cleaning
We inspected the HR surface after the FC cleaning and took a bunch of pictures.
https://photos.app.goo.gl/sJKAhizVC5jD4iK18
There are still a lot of stains on the surface. Some of the stains, such as the one stretching long, may have different origin from the spot like stains of this time.
Note that these stains are extremely faint, and you cannot see them under normal condition. Only with a military grade LED light with 3500 Lumens, and seen from a proper angle, you can see these stains.
We will see how these stains contribute to the surface absorption of the mirror.
FC again
Before putting the mirror into the mirror box, we applied FC again within the central 190mm diameter.
Then we put the mirror face down onto the bottom plate of the mirror box using 4 jacks.
Mirror box cannot be closed
After sitting the mirror nicely at the center of the base plate, we assembled the mirror box.
Then we noticed that we cannot close the top lid of the box.
This is because of the following reason:
- On the AR surface of the mirror, we have a protection ring to prevent magnets from touching the lid.
- Because of this ring, the effective diameter of the mirror is slightly enlarged (by 2mm).
- This makes the three poles (to support the mirror from the side) to lean slightly outward.
- Then the screw holes at the top of the poles no longer align with the holes on the top lid, making it impossible to put screws.
In order to avoid this problem, we decided to put shallow grooves on the sleeves of the poles so that poles can stand straight even with the protection ring.
The modification will be finished by 3PM tomorrow. So we will continue the work after that.
