[Hasegawa, Akutsu]
Today's afternoon, we moved to EYC chamber with tools, and started replacement of oplev winodws at EYC. So far we just detached four flange assemblies. We will continue tomorrow.
[Hasegawa, Akutsu (Hsieh: afternoon)]
We detached two flange assemblies; six flange assemblies in total are now detached from the inner and the outer shields of the EYC chamber, thanks to the quick indium cutting... (but this made another issue).
Now all the flange assemblies contain AR-coated windows, but re-torqueing of the screws of them would be required later (not today). The flange assemblies themselves are now stored under the duct in the EY room.
Note: now all the M5x20 screws that fixing three parts of each flange have vent holes; they were replaced from the original ones to the vent-holed ones. Because we did not replace them of IYC, so we need to do the work later.
[Morozumi, Akutsu]
Abstract
Continued work from the last Thursday; we have completed to install six flange assemblies to the inner and outer shields in the EYC chamber.
Re-torquing
We started our work today with re-torquing the M5x20 screws of flange assemblies.
Installation
I entered into the EYC chamber to install those flange assemblies (due to the number of concurent workers, we faced a shortage of full-armored clean wears today; fortunately I had it). Indeed, the installation work was quite tough, as the aviable space was quite limited due to rails for cryopayload installation. Maji de semai!!! Anyway I've succeeded to open the corresponding shutters and install the flange assemblies.
I don't recommend to repeat the same situation as today again!... the flange assemblies should be installed BEFORE the rails for cryopayload installation are inserted, otherwise you need to become thinner.
Summary
So far, the number of anti-reflection (AR) coated windows are as follows.
| Inner shield | Outer shield | Chamber | |
| Planned | 3 | 3 | 3 |
| Installed so far | 3 | 3 | 0 |
| Diff. | 0 | 0 | 3 |
Incidents
During the installation work, I have lost two things: (1) a short hex wrentch with short neck (for M4) (2) one of M4 screws that was used to close (and hold) a shutter in the "-X+Y" direction of the inner shield. They fell down anywhere in the cryostat.
2 pieces of ICF152 oplev viewport windows were installed to EYA; they are at the level of the main beam; the serial numbers of them are S/N0030 for -X side and 0031 for +X side.
The torque: started with 5Nm, then 10Nm, then 15Nm for ICF152 part; the small screws part (for fixing a glass), the exerted torque was limited less than 5Nm.
Fig. 1, 2, and 3 shows "-X" side. You can see an attached aluminum(?) mirror on a sapphire dummy through the windows.
And so Fig. 5 and 6 for "+X" side.
A Mistake: not EYA, but EYC.
Mistake: not EYA but EYC.