Yamaguchi, Uchiyama, Kimura, Yasui
We started warming up EX about 2 PM.
(1) We Connected 4 TMPs(#32, 33, 39, 37).
(2) Stop two cryocooler for the payload(P-54, P-56) and one cryocooler for teh radiation shield(P-55).
(3) We turned on 8K shield heater. The current input heat is 10 W.
At that time, we didn't stop the ION pumps. We expected 7 vacuum pumps would suppress pressure increases due to temperature increases.
at 14:56 GVex was closed by the interlock system due to increase of the vacuum pressure. 7 vacuum pumps were not enough.
Kimura-sama, Yasui-sama went to Xend and stop all Ion pumps(#33, 37, 31). They operated one more TMP(#31).
about 4 PM. Since we observed reduction of the vacuum pressure in X_30, We opened GVex finally.
Nakagaki, Yasui
We stopped the other cryocooler for radiation shield(P-53) at 11:27.
The compressor operating time was 28231.5h.
Nakagaki, Yasui
We stopped two duct shield cryocoolers.
12:36 Xer (The compressor operating time was 12226.5h)
12:37 Xea (The compressor operating time was 10352.1h)
We turned on the heater on the BRT side of duct shield of EXC at 8:15, because the temperature of this duct shield was enough higher than 150K.
The heater power is about 8W.
Note that we did not turned on the Arm side at this time.
We turned on the heater on the Arm side of duct shield of EXC at 8:18, because the temperature of this duct shield was enough higher than 150K.
The heater power is about 8W.
Now, both side of EXC duct shields are heating up.
Since I failed upload the screenshot of the heater control panel for the BRT side of the duct shield yesterday, I upload it here.
Fig. 1: EX-BRT side.
Fig. 2: EX-Arm side.
Since the temperatures at the cold heads of the cryocoolers for the duct shields of IYC reached the room temperature, we turned off both sides of the duct shield heaters at 9:45 a.m. on January 5th, 2026.
I turned off the heater at the top of the inner ratioation shield.