Full-Acceptance Detector Integration at MEIC Vasiliy Morozov for MEIC Study Group Electron Ion Collider Users Meeting, Stony Brook University June 27, 2014

EIC Users Meeting 6/27/142 Lattice design of geometrically-matched collider rings completed Detector locations minimize synchrotron and hadronic backgrounds ̶ Close to arc where ions exit ̶ Far from arc where electron exit Collider Rings IPs e-e- ions e-e- IP

EIC Users Meeting 6/27/ mrad crossing angle ̶ Improved detection, no parasitic collisions, fast beam separation Forward hadron detection in three stages ̶ Endcap ̶ Small dipole covering angles up to a few degrees ̶ Far forward, up to one degree, for particles passing through accelerator quads Low-Q 2 tagger ̶ Small-angle electron detection Full-Acceptance Detector R. Ent, C.E. Hyde, P. Nadel-Turonski

EIC Users Meeting 6/27/144 IR design features ̶ Based on triplet Final Focusing Blocks (FFB) ̶ Asymmetric design to satisfy detector requirements and reduce chromaticity ̶ Spectrometer dipoles before and after downstream FFB, second focus downstream of IP ̶ No dispersion at IP, downstream dispersion suppression designed to function as CCB Ion IR Optics IP ions matching section\ coupling comp. FFB detector elements CCB\ geom. match\ disp. suppression matching section\ coupling comp. matching section

EIC Users Meeting 6/27/145 Detector Modeling & Machine Integration Fully-integrated detector and interaction region satisfying –Detector requirements: full acceptance and high resolution –Beam dynamics requirements: consistent with non-linear dynamics requirements –Geometric constraints: matched collider ring footprints far forward hadron detection low-Q 2 electron detection large-aperture electron quads small-diameter electron quads central detector with endcaps ion quads 50 mrad beam (crab) crossing angle n,  e p p small angle hadron detection ~60 mrad bend (from GEANT4) 2 Tm dipole Endcap Ion quadrupoles Electron quadrupoles 1 m 1 m1 m1 m1 m IPFP Roman pots Thin exit windows Fixed trackers Trackers and “donut” calorimeter RICH + TORCH? dual-solenoid in common cryostat 4 m coil barrel DIRC + TOF EM calorimeter Tracking EM calorimeter e/π threshold Cherenkov

EIC Users Meeting 6/27/146 Far-Forward Acceptance Transmission of particles with initial angular and  p/p spread vs peak field –Quad apertures = B max / (fixed field 100 GeV/c) –Uniform particle distribution of  0.7 in  p/p and  1  in horizontal angle originating at IP –Transmitted particles are indicated in blue (the box outlines acceptance of interest) 6 T max 9 T max 12 T max  electron beam

EIC Users Meeting 6/27/147 Momentum & Angular Resolution –Protons with  p/p spread are launched at different angles to nominal trajectory –Resulting deflection is observed at the second focal point –Particles with large deflections can be detected closer to the dipole  electron beam ±10 60 GeV/c |  p/p| >  x,y = 0

EIC Users Meeting 6/27/148 Far-Forward Acceptance GEMC simulation framework developed by M. Ungaro MILOU DVCS event generator Detection of recoil protons produced in DVCS process by forward detectors –Acceptance limitation due to beam stay-clear rather than magnet apertures in this case  Beam stay-clear depends the emittances achievable by beam cooling: Z.W. Zhao

EIC Users Meeting 6/27/149 Design features similar to that of ion IR ̶ Triplet Final Focusing Blocks (FFB) ̶ Asymmetric design to satisfy detector requirements and reduce chromaticity ̶ Spectrometer dipole after downstream FFB, second focus downstream of IP ̶ No dispersion at IP, downstream dispersion suppression by chicane Electron IR Optics IP electrons matching section FFB detector elements disp. suppression matching section\ coupling comp. CCB matching section\ coupling comp.

EIC Users Meeting 6/27/1410 Small-Angle Electron Detection Low-Q 2 tagger –Dipole chicane for high-resolution detection of low-Q 2 electrons low-Q 2 tagger final focusing elements e-e- ions e-e- Electron beam aligned with solenoid axis x e-e- (top view)

EIC Users Meeting 6/27/1411 Compton polarimeter in low-Q 2 chicane Same polarization as at the IP due to zero net bend Non-invasive continuous polarization monitoring Polarization measurement accuracy of ~1% expected No interference with quasi real photon tagging detectors Electron Polarimetry c Laser + Fabry Perot cavity e - beam Quasi-real high-energy photon tagger Quasi-real low-energy photon tagger Electron tracking detector Photon calorimeter A. Camsonne, D. Gaskell

EIC Users Meeting 6/27/1412 Crab Crossing Restores effective head-on collisions with 50 crossing angle –Luminosity preserved Two feasible technologies –Deflective crabbing: transverse electric field of SRF cavities (developed at ODU) –Dispersive crabbing: regular accelerating/bunching cavities in dispersive region Two possible schemes –Global: one set of cavities upstream of IP next to FFB –Local One set of cavities upstream of IP next to FFB Another set of cavities  (n+1/2)  downstream of IP IP e-e- ions global/local crab cavities local crab cavities

EIC Users Meeting 6/27/1413 Lattice design of geometrically-matched collider rings developed Interaction regions integrated into collider rings Detector requirements fully satisfied Ongoing and future work ̶ Detector modeling ̶ Polarimetry development ̶ Design optimization ̶ Design of interaction region magnets ̶ Systematic investigation of non-linear dynamics ̶ Development of beam diagnostics and orbit correction scheme Acknowledgements ̶ P. Brindza, A. Camsonne, Ya.S. Derbenev, R. Ent, D. Gaskell, F. Lin, P. Nadel-Turonski, M. Ungaro, Y. Zhang  JLab ̶ C.E. Hyde, K. Park  Old Dominion University ̶ M. Sullivan  SLAC ̶ Z.W. Zhao  JLab & Old Dominion University Summary & Outlook