CRY (Cryostat IX)

masahide.tamaki - 13:50 Friday 08 March 2024 (28788)

viewport cleaning

[Ushiba, Tamaki]

We cleaned viewports which was removed yesterday.
Basically, we wiped them with Vectro Alpha and aceton / isopropanol as follows.

For -x-y side of MN outer viewport, we wiped only the inside.
For +x-y side of MN inner viewport, we wiped only the outside.
For -x-y side of MN inner viewport, we wiped only the outside.

Fig1-4: -x-y side of MN outer viewport (inside / outside / inside after cleaning / outside after cleaning)
Fig5-8: +x-y side of MN inner viewport (inside / outside / inside after cleaning / outside after cleaning)
Fig9-12: -x-y side of MN inner viewport (inside / outside / inside after cleaning / outside after cleaning)

► We were able to clean it up with just a wipe, then the work on the other viewports seems relatively easy (although we have to use organic solvents in the vacuum chamber if the viewports are not removed as in this case).

► Considering the surfaces wiped (inside for outer viewport, outside for inner viewports), it seems unlikely that a similar problem is occurring on the mirror.

► After wiping the viewports, no stains were found on the wipers.

Images attached to this report

28788_1709873219_mn+x-yInnerOutClean.png

Comments to this report:

takafumi.ushiba - 18:29 Tuesday 12 March 2024 (28826)

[Uchiyama, Ushiba]

Abstract:

We reinstalled cleaned viewports into the IXC.
Then, we tried to clean the viewport (MN +X -Y side, outer) inside the cryostat.
Though it can be cleaned, the smell of organic solvent fills the cryostat even if we used small amount of it.
So, it is better to remove the viewports and clean them one by one at the outside of the cryostat.

Detail:

First, we retighten the screws, which are used for fixing viewports onto the flanges, with the torque wrench (5 Nm).
Then, we fixed them onto the radiation shields (3Nm -> 4Nm -> 5Nm -> 5Nm).

After that, we tried to clean the +X -Y side viewport on the outer radiation shield for MN OpLev.
Figure 1 shows the picture before cleaning.
First, we cleaned inner surface with isopropanor but stains still remain (fig2).
Then, we cleaned outer surface and then successfully wiped them out (fig3: inner surface and fig4: outer surface).
So, it is not ture that the contamination is existing between outer and inner radiation shields.

During the cleaning, we noticed the smell of organic solvent fills inside the cryostat even though we used small amount of organic solvent for wiping.
So, it is not good to wipe many viewports inside the cryostat.

Images attached to this comment

masahide.tamaki - 16:11 Monday 18 March 2024 (28885)

[Miyoki, Yuzurihara, Ishikawa, Tamaki]

First, we removed the 6 viewports (MN +X+Y outer / inner・MN -X+Y outer / inner・TM -X+Y outer / inner).
Then, they were cleaned up along with two that had been previously removed (TM -X-Y outer / inner・klog28838).

Basically, they could be cleaned up as same as the original post, but TM -X+Y inner had a small mark which could not be removed (Fig.1).

►Cleaned viewports have not been reinstalled yet.
►The viewports for PF oplev have not been removed yet.

Images attached to this comment

masahide.tamaki - 17:13 Tuesday 19 March 2024 (28906)

[Uchiyama, Yuzurihara, Ishikawa, Tamaki]

I reinstalled 6 viewports which were removed & cleaned yesterday (MN +X+Y outer / inner・MN -X+Y outer / inner・TM -X+Y outer / inner) and last week (TM -X-Y outer / inner).

And also PF -X+Y inner was removed (so PF -X+Y outer・ PF -X-Y outer / inner remain without being cleaned).

takashi.uchiyama - 18:26 Thursday 21 March 2024 (28930)

2024/03/21

mTakahashi, Uchiyama

We removed two viewports (PF -X+Y outer, PF -X-Y outer) from IXC.
While removing the viewport (PF -X-Y outer), I dropped one screw between SI and the outer shield but we finally found it.

At present, 4 viewports in the IXC cryostat require cleaning.
3 viewports have been removed, and 1 viewport (PF -X-Y inner) is still inside.

masahide.tamaki - 17:05 Monday 25 March 2024 (28963)

[Ushiba, Tanaka, Tamaki]

We cleaned viewports which was removed by Uchiyama-san last week and reinstalled them (Fig1-3: front / back side after clean).
Also we removed the one left behind (PF_in_-X-Y), and cleaned + reinstalled it (we forgot to take a photo).

memo
► PF_out_-X+Y: front side was foggy / back side was also a little foggy
► PF_out_-X-Y: front was foggy
► PF_in_-X+Y: the mark on front side was not removed perfectly / back side was foggy
► PF_in_-X-Y: the mark on front side was not removed perfectly / back side was foggy

Images attached to this comment