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