A flange member is provided on {TAIL ~ an outer wall} of the vacuum chamber to cover {HEAD ~ an opening} in the wall 
A flange member is provided on { TAIL ~ an outer wall } of the vacuum chamber to cover { HEAD ~ an opening } in the wall
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH