1. Detector / Interaction Region Integration Vasiliy Morozov, Charles Hyde, Pawel Nadel-Turonski Joint CASA/Accelerator and Nuclear Physics MEIC/ELIC Meeting February 3, 2012

2. -- 2 -- V.S. Morozov 02/03/2012 Motivation Pawel Nadel-Turonski

3. -- 3 -- V.S. Morozov 02/03/2012 Central detector EM Calorimeter Hadron Calorimeter Muon Detector EM Calorimeter Solenoid yoke + Muon Detector TOF HTCC RICH Cerenkov Tracking 2 m 3 m 2 m 4-5 m Solenoid yoke + Hadronic Calorimeter MEIC Primary “Full-Acceptance” Detector Distance IP – electron FFQs = 3.5 m Distance IP – ion FFQs = 7.0 m (Driven by push to 0.5  detection before ion FFQs) Pawel Nadel-Turonski & Rolf Ent solenoid electron FFQs 50 mrad 0 mrad ion dipole w/ detectors (approximately to scale) ions electrons IP ion FFQs 2+3 m 2 m Make use of the (50 mr) crossing angle for ions! detectors Central detector, more detection space in ion direction as particles have higher momenta Detect particles with angles below 0.5 o beyond ion FFQs and in arcs. Detect particles with angles down to 0.5 o before ion FFQs. Need up to 2 Tm dipole in addition to central solenoid. 7 m

4. -- 4 -- V.S. Morozov 02/03/2012 GEANT4 Model Detector solenoid – 4 T field at the center, 5 m long, 2.5 m inner radius, IP 2 m downstream from edge Small spectrometer dipole in front of the FFB – 1.2 T (@ 60 GeV/c), 1 m long, hard-edge uniform field – Interaction plane and dipole are rotated around z to compensate orbit offset FFB Big spectrometer dipole – 4 m downstream of the FFB, sector bend, 3.5 m long, 60 mrad bending angle (12 Tm, 3.43 T @ 60 GeV/c),  20 cm square aperture

5. -- 5 -- V.S. Morozov 02/03/2012 Separation of Electron and Ion Beams

6. -- 6 -- V.S. Morozov 02/03/2012 Beam Parallel after FFB FFB: quad lengths = 1.2, 2.4, 1.2 m, quad strengths @ 100 GeV/c = -79.6, 41.1, -23.1 T/m 1.2 Tm (@ 60 GeV/c) outward-bending dipole in front of the final focus 12 Tm (@ 60 GeV/c) inward-bending dipole 4 m downstream of the final focus Pawel Nadel-Turonski & Alex Bogacz

7. -- 7 -- V.S. Morozov 02/03/2012 FFB Acceptance 60 GeV/c protons, each quad aperture = B max / (field gradient @ 100 GeV/c) 6 T max 9 T max 12 T max

8. -- 8 -- V.S. Morozov 02/03/2012 FFB Acceptance for Neutrons 6 T max 9 T max 12 T max Neutrons uniformly distributed within  1  horizontal & vertical angles around 60 GeV/c proton beam Each quad aperture = B max / (field gradient @ 100 GeV/c)

9. -- 9 -- V.S. Morozov 02/03/2012 System Acceptance at 6 T max Field Uniform distribution horizontally & vertically within  1  around 60 GeV/c protons Each quad aperture = 6 T / (field gradient @ 100 GeV/c)  p/p = 0 neutrons  p/p = -0.5  p/p = 0.5  electron beam

10. -- 10 -- V.S. Morozov 02/03/2012 Momentum & Angle Resolution Beam parallel after the final focus Protons with  p/p spread launched at different angles to nominal 60 GeV/c trajectory Red hashed band indicates  10  beam stay-clear

11. -- 11 -- V.S. Morozov 02/03/2012 Momentum & Angle Resolution Beam parallel after the final focus Protons with  p/p spread launched at different angles to nominal 60 GeV/c trajectory Red hashed band indicates  10  beam stay-clear |  p/p| > 0.03 @  x,y = 0

12. -- 12 -- V.S. Morozov 02/03/2012 Momentum & Angle Resolution Beam parallel after the final focus Protons with different  p/p launched with  x spread around nominal 60 GeV/c trajectory Red hashed band indicates  10  beam stay-clear

13. -- 13 -- V.S. Morozov 02/03/2012 Momentum & Angle Resolution Beam parallel after the final focus Protons with different  p/p launched with  x spread around nominal 60 GeV/c trajectory Red hashed band indicates  10  beam stay-clear |  x | > 2 mrad @  p/p = 0

14. -- 14 -- V.S. Morozov 02/03/2012 Beam Focused after FFB FFB: quad lengths = 1.2, 2.4, 1.2 m, quad strengths @ 100 GeV/c = -89.0, 51.1, -35.7 T/m 1.2 Tm (@ 60 GeV/c) outward-bending dipole in front of the final focus 12 Tm (@ 60 GeV/c) inward-bending dipole 4 m downstream of the final focus Pawel Nadel-Turonski & Charles Hyde

15. -- 15 -- V.S. Morozov 02/03/2012 System Acceptance at 6 T max Field Uniform distribution horizontally & vertically within  1  around 60 GeV/c protons Each quad aperture = 6 T / (field gradient @ 100 GeV/c)  p/p = 0 neutrons  p/p = -0.5  p/p = 0.5  electron beam

16. -- 16 -- V.S. Morozov 02/03/2012 System Acceptance with Varied Quad Fields Uniform distribution horizontally & vertically within  1  around 60 GeV/c protons Quad apertures = 9, 9, 6 T / (field gradient @ 100 GeV/c)  p/p = -0.5  p/p = 0  p/p = 0.5 neutrons  electron beam

17. -- 17 -- V.S. Morozov 02/03/2012 Detector / IR Layout n p e

18. -- 18 -- V.S. Morozov 02/03/2012 Momentum & Angle Resolution Beam focused after the FFB Protons with  p/p spread launched at different angles to nominal 60 GeV/c trajectory Red hashed band indicates  10  beam stay-clear

19. -- 19 -- V.S. Morozov 02/03/2012 Momentum & Angle Resolution Beam focused after the FFB Protons with  p/p spread launched at different angles to nominal 60 GeV/c trajectory Red hashed band indicates  10  beam stay-clear |  p/p| > 0.005 @  x,y = 0

20. -- 20 -- V.S. Morozov 02/03/2012 Momentum & Angle Resolution Beam focused after the FFB Protons with different  p/p launched with  x spread around nominal 60 GeV/c trajectory Red hashed band indicates  10  beam stay-clear

21. -- 21 -- V.S. Morozov 02/03/2012 Momentum & Angle Resolution Beam focused after the FFB Protons with different  p/p launched with  x spread around nominal 60 GeV/c trajectory Red hashed band indicates  10  beam stay-clear |  x | > N/A @  p/p = 0 |  x | > 3 mrad @  p/p = 0

22. -- 22 -- V.S. Morozov 02/03/2012 Electron FFB Quads nearest to IP are inside strong solenoid fringe field  either permanent-magnet or super-conducting quadrupoles Consider hybrid electron FFB design (P. Nadel-Turonski & A. Bogacz): first two quads are permanent-magnet, subsequent quads are super- conducting (smaller OD) Outer radius of a permanent-magnet quad (M. Sullivan) depending on the inner radius and field gradient: r inner = 20 mm, G = 15 T/m  r outer = 23.4 mm Permanent-magnet quad – can be placed closer to IP – covers smaller solid angle  greater acceptance

23. -- 23 -- V.S. Morozov 02/03/2012 Hybrid Electron FFB Optics at 3 GeV/c Drift lengths: 3, 0.25, 0.25, 1, 0.2 m Quad lengths: 0.5, 0.5, 0.5, 0.5, 0.3 m Quad inner radii: 2, 2, 2, 4, 4 cm; quad outer radii: 3, 3, 9, 11, 11 cm Quad strengths: -15.0, 15.0, -5.87, 7.70, -8.48 T/m

24. -- 24 -- V.S. Morozov 02/03/2012 Hybrid Electron FFB Optics at 5 GeV/c Drift lengths: 3, 0.25, 0.25, 1, 0.2 m Quad lengths: 0.5, 0.5, 0.5, 0.5, 0.3 m Quad inner radii: 2, 2, 2, 4, 4 cm; quad outer radii: 3, 3, 9, 11, 11 cm Quad strengths: -15.0, 15.0, -14.7, 20.4, -19.3 T/m

25. -- 25 -- V.S. Morozov 02/03/2012 Hybrid Electron FFB Optics at 11 GeV/c Drift lengths: 3, 0.25, 0.25, 1, 0.2 m Quad lengths: 0.5, 0.5, 0.5, 0.5, 0.3 m Quad inner radii: 2, 2, 2, 4, 4 cm; quad outer radii: 3, 3, 9, 11, 11 cm Quad strengths: -15.0, 15.0, -34.0, 45.6, -38.0 T/m

26. -- 26 -- V.S. Morozov 02/03/2012 Detector / IR Layout n p e

27. -- 27 -- V.S. Morozov 02/03/2012 Upstream Ion / Downstream Electron Side Electron FFB – 4 m distance to IP? – 1  polar angle acceptance – Superconducting quads (solenoid fringe field, small size, large aperture) – Electron beam focused inside spectrometer dipole? Ion FFB – First quad immediately after first electron quad at ~4.5-5 m – Ion quads interleaved with electron quads

28. -- 28 -- V.S. Morozov 02/03/2012 Conclusions Completed the study of forward ion tagging, a few design choices to be made Request to nuclear physics – Come up with specs for detector resolution requirements – this will help to motivate and make the design choices, in particular, quantify the advantages of focused vs parallel downstream ion beam To do list – Design forward electron tagging and upstream ion FFB – Design optimization, e.g. acceptance of the FFB using genetic algorithm – Integration into the ring optics, such as decoupling, dispersion compensation, understanding effect of large-aperture quadrupoles on the optics, etc. – Evaluation of the engineering aspects, such as magnet parameters, electron and ion beam line separation, etc.