[Moller] beam line layout

[Jay Benesch]

https://moller.jlab.org/cgi-bin/DocDB/private/ShowDocument?docid=706

The 1 April layout of the beam line has been uploaded.  There may be mm shifts of items inside the BCM/Unser/BCM box once measurements are made but those will have no effect on physics.  No other changes are expected except corrector type (same centers and lengths).   Note the 6120 mm dimension at lower right, the face of the final accelerator gate valve.  This is the interface dimension to downstream efforts by others.  The subsequent bellows  (6031.1) is needed for alignment but it needn't be in that location, it just has to be before the target.   The upstream Z of a 69" OD cylinder centered at 4500 mm is 5376.3 mm, 743.7 mm from the 6120 mm gate valve flange and 654.8 mm from the end of the unstressed bellows.   I've made this document viewable by the public and submitted it under my name since none of the ME folk who worked on it are in author list.   The collaboration should consider whether the ~70 detailed and assembly drawings which will result from this work should be placed in the MOLLER docdb as well as the JLab documents cache.