I measured residual gas pressure inside of IYC with Q-mass during cooling of IYC payload.
Please confirm attached three graphs.
The conditions during measurements are as follows;
IYC BS side inside pressure=1.1 x 10^-6 Pa
IYC arm side inside pressure=3.1 x 10^-6 Pa
Yfa (duct shield cryo-cooler arm side) inside pressure=4.6 x 10^-6 Pa
IYC inside pressure=2.3~2.4 x 10^-6 Pa
8 K shield temp:
Top=14.6 K
TM=92.2 K
Condition of view-ports;
There are "NO' frosting on the surface of view ports visually.
From the measurement, it was confirmed that the tendency of the pressure drop of the residual gas due to the cooling of the inner shield has stopped.
