[FFA_CEBAF_Collab] extraction concept

[Jay Benesch]

Colleagues, 

An idea that came to me this morning.    I suspect it doesn't fit, but have we any extraction ideas that do? 

1. assume that Hall D will run only as a solo hall, or will be closed in favor of resuming polarized photon work in Hall B, albeit with lower polarization since drift would be ~50 m instead of 75m 
2. build the SW splitter entirely in the straight, not encroaching on the arc
3. if ABC want, say, seventh pass beam, put in the eighth pass dumplet and set up the machine. 
4. within each splitter have a C magnet which is unpowered for recirculation and picks off the beam, as in the BSY, when extraction is desired.  Vacuum will have to be common for the multiple lines. 
5. direct whichever pass beam is extracted into a chicane which leads to the transport recombiner and vertical RF separators.  

Also, I checked with SRF engineers: the cryomodule internal supports can deal with ~5% slope so a ramp 16-20 m long to a false floor 80 cm above the real one would be compatible. 

Jay