The main beam viewport window Category M (JGW-D2213701) was inserted to the viewport adapter (the thicker one of JGW-D1402928). Then I attached it to the already attached ICF203-152 conversion flange (19310) on the IMM chamber in the +Y direction. The thicker side of the window due to the wedge (marked with a red pen on the flange) is oriented in the +X direction, basing on the design (see JGW-G2112943).

• Note that, as in the Cat.M window specification in the above link, the AR coating on the both sides of the window is best designed for 30 deg incident angle beam.
• M8x40 bolts are used (5->10->15 Nm). Small-sized washers are required.
• For the Phillips-head (plus-head) screws to fix the glass to the adapter, they were fully fasten by hand, not a torque wrench, as the head grooves were easily broken when I tried with the torque wrench.... This design should be modified in the next time, if possible.
• See also here.
• For reference about the similiar works, see 8032, 7779, 7465, 4115...