Full-Acceptance Detector Integration at MEIC

Transcription

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

2 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 IP ions e - ions e - EIC Users Meeting 6/27/14 2

3 50 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 Full-Acceptance Detector Small-angle electron detection EIC Users Meeting 6/27/14 3 R. Ent, C.E. Hyde, P. Nadel-Turonski

4 IR design features Ion IR Optics 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 matching section IP matching section\ coupling comp. FFB FFB detector elements CCB\ geom. match\ disp. suppression matching section\ coupling comp. ions EIC Users Meeting 6/27/14 4

5 EM calorimeter e/π threshold Cherenkov EM calorimeter 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 low-q 2 electron detection (from GEANT4) large-aperture electron quads small angle hadron detection ion quads IP ~60 mrad bend far forward hadron detection FP n, g p p 50 mrad beam (crab) crossing angle central detector with endcaps small-diameter electron quads Thin exit windows Fixed trackers Roman pots e dual-solenoid in common cryostat 4 m coil RICH + barrel DIRC + TOF TORCH? Tracking EM calorimeter Endcap 1 m 2 Tm dipole 1 m Trackers and donut calorimeter Ion quadrupoles Electron quadrupoles EIC Users Meeting 6/27/14 5

6 electron beam 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 EIC Users Meeting 6/27/14 6

7 electron beam 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 p/p > x,y = 0 60 GeV/c EIC Users Meeting 6/27/14 7

8 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: 24 / 5 μm, / 0.24 mrad x/ y x/ y x/ y x'/ y' x/ y x/ y EIC Users Meeting 6/27/14 8 Z.W. Zhao

9 Electron IR Optics 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 electrons CCB matching section matching section\ coupling comp. FFB FFB detector elements disp. suppression matching section\ coupling comp. IP EIC Users Meeting 6/27/14 9

10 Small-Angle Electron Detection Low-Q 2 tagger Dipole chicane for high-resolution detection of low-q 2 electrons e - x e - low-q 2 tagger (top view) ions Electron beam aligned with solenoid axis final focusing elements e - EIC Users Meeting 6/27/14 10

11 Electron Polarimetry 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 Photon calorimeter c Quasi-real low-energy photon tagger Laser + Fabry Perot cavity Quasi-real high-energy photon tagger Electron tracking detector e - beam EIC Users Meeting 6/27/14 11 A. Camsonne, D. Gaskell

12 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 local crab cavities ions IP global/local crab cavities e - EIC Users Meeting 6/27/14 12

13 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 Summary & Outlook Z.W. Zhao JLab & Old Dominion University EIC Users Meeting 6/27/14 13