Transfer Line for EIC

Proposed EIC layout

Transfer line requirements Achromatic Keep Sync. Rad. Growth under control Room for matching region, diagnostic region Room for compression chicane if needed Room to make a spreader step Minimize number of dipoles (cost)

EIC Ion ring and e- ring IP IP Injection

Electron ring CEBAF coordinates Injection

Option 1 design choices Utilizes 3.6 meters dipoles (68 of them) Quadrupoles are QR type (73 of them) 120 degrees FODO. First ARC bends 175.84 degrees. Second ARC bends 197.7631 in other direction Injecting at -21.9231 degrees. Leaving 10mrad for septum. Straight of 21 meters between the two arcs. Straight of 23 meters after 2nd arc (matching quads in it)

Proposed transfer line

CEBAF to EIC

Optical properties

Emittance growth 0.11 mm normalized

Alternate option Making the design choice that one can inject at the 90 degrees point. (Assuming beam quality is not an issue when doing trickle injection). Drastic reduction in footprint, number of magnets and consequently cost. Almost no synch rad loss. Beam quality preserved.

Alternate option

Emittance growth option 2 80 μm.rad

Optical properties option 2

Component count and layout Option Quads Dipoles Tunnel length (m) #1 injecting front of arc 73 68 382 #2 injection at 90 degs. 46 16 285

Ring Injection We will start with a PEPII like design: Dispersion free injection insertion Septum+ RF kickers Insertion with five quad, one of them split to inject and upright beam ellipse Closed orbit will be bumped by RF and DC kickers Vertical injection because of greater dynamic aperture in this plane and absence of synchrotron oscillations.

Things to check Beam quality after half an arc Effect of injected beam (still in the process of damping) on detectors (need to design collimators to be installed in the rest of the arc for beam dumping and envelope control) Beam Beam effects due to degraded injected beam Effect on polarization (dilution?)