I found a correlation between the change in VIS-ITMX_MN_DAMP_L_INMON that was pointed out by Ushiba-kun and the sudden temperature reduction of  IX_4K_REF4_HEAD and IX_4K_COOLING_BAR_REF2.

So, some heat shock caused this change.

In addition, the cryocooler, which was turned off today, seemed to be connected with the REF4 cooling bar, not REF2. So, should we change the cryocooler that should be turned off?

Note that following is EY situation not IX.

Current (wrong) channel assignment:
- EY-No.1 #Ch3 = K1:CRY-TEMPERATURE_EY_4K_COOLING_BAR_REF4
- EY-No.1 #Ch6 = K1:CRY-TEMPERATURE_EY_4K_COOLING_BAR_REF2

Correct channel assignment:
- EY-No.1 #Ch3 = K1:CRY-TEMPERATURE_EY_4K_COOLING_BAR_REF2
- EY-No.1 #Ch6 = K1:CRY-TEMPERATURE_EY_4K_COOLING_BAR_REF4

Is it possible that a same thing is happening in IX (IY and EX)?

> Is it possible that a same thing is happening in IX (IY and EX)?

I guess YES in IX, however, No in IY and EX, I confirmed.

Although I expected that the IX_4K_COOLING_BAR_REF2 temperature would increase because of the IM heatup, no changes at all. So we need to turn off the REF4 cryocooler.

FIg.1 shows the VIS-ITMX_DAMP_L_INMON changes when we turned on/off the REF2/4 coolers.

Just after turning off REF2 cryocooler around -2days 6 hours, VIS-ITMX_DAMP_L_INMON started decreasing toward the Y1=-4899 from which the strange touching seemed to happen.

When we changed the cryocoolers from REF2 to REF4 which was turned off, the speed of decreasing of VIS-ITMX_DAMP_L_INMON became larger. However, it became smaller again when the REF2 cryocooler reached its minimum temperature.

By the way, the decrease of VIS-ITMX_DAMP_L_INMON to -4899 is a good sign or not?

Fig.1 shows, the changes of VIS-ITMX_DAMP_{L, V, P, R}_INMON, and 4K_REF{2, 4}_4K_HEAD, and 4K_COOLING_BAR_REF{2, 4} after turning off both REF2/4 cryocoolers.

Two lines in each graph show the values (named A) before turning on both REF2/4 cryocoolers about -18 days, and values (named B) that were reported by Ushiba-kun when the strange trends appeared.

• VIS-ITMX_DAMP_{L}_INMON seemed to rapidly go below A and go to B.
• VIS-ITMX_DAMP_{R}_INMON seemed to rapidly go to A and B.
• VIS-ITMX_DAMP_{V, P}_INMON seemed to slowly go to A and B.

Are they good signs or not??

More reports,

• VIS-ITMX_DAMP_{L}_INMON seemed to rapidly go to B. Good sign?
• VIS-ITMX_DAMP_{R}_INMON seemed to rapidly go over B and got to A. Good Sign?
• VIS-ITMX_DAMP_{V, P}_INMON seemed to slowly move away from A and B. How should we evaluate??

More reports,

• VIS-ITMX_DAMP_{L}_INMON seemed to mostly reach B
• VIS-ITMX_DAMP_{R}_INMON seemed to reach A
• VIS-ITMX_DAMP_{V, P}_INMON seemed to show increasing trends in the recent 12 hours (and to be set around A).

More reports,

• VIS-ITMX_DAMP_{L}_INMON seemed to reach B
• VIS-ITMX_DAMP_{R}_INMON seemed to reach A
• VIS-ITMX_DAMP_{V, P}_INMON seemed to be between A and B.