1. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 1 Status of Baseline Linac and RLAs Design – IDR Presentation + Annex 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25

2. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 2 Linac and RLAs  Goals 244 MeV 0.6 GeV/pass 3.6 GeV 0.9 GeV 146 m 79 m 2 GeV/pass 264 m 12.6 GeV IDS Tasks: Define beamlines/lattices for all components Matrix based end-to-end simulation (machine acceptance) (OptiM vs ELEGANT) Field map based end-to-end simulation (transmission) GPT vs G4Beamline Error sensitivity analysis Component count and costing 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25 79 m RLA with FFAG Arcs

3. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 3 Linac and RLA Design  Status Presently completed lattices Linear pre-accelerator – solenoid focusing 4.5 pass Dogbone RLA × 2 (RLA I + RLA II) Optimized multi-pass linac optics (bisected - quad profile along the linac) Droplet return arcs (4) matched to the linacs Transfer lines between the components – injection chicanes Droplet arcs crossing – Double achromat Optics design Chromatic corrections with sextupoles at Spr/Rec junctions Error analysis for the Arc lattices (proof-or-principle) Magnet misalignment tolerance – DIMAD Monte Carlo Simulation Focusing errors tolerance – betatron mismatch sensitivity Piece-wise end-to-end simulation with OptiM (pre-accelerator + RLA I & II) 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25

4. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 4 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25 Linear Pre-accelerator – 244 MeV to 909 MeV Transverse acceptance (normalized): (2.5) 2   = 30 mm rad Longitudinal acceptance: (2.5) 2   p  z /m  c  = 150 mm 6 short cryos 15 MV/m 8 medium cryos 17 MV/m 11 long cryos 17 MV/m 1.1 Tesla solenoid 1.4 Tesla solenoid 2.4 Tesla solenoid

5. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 5 Solenoid Model (Superfish) 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25 outer coil inner coil shield ‘Soft-edge’ Solenoid

6. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 6 Two-cell cavity (201 MHz) – COMSOL Morteza Aslaninejad Cristian Bontoiu J ü rgen Pozimski 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25

7. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 7 Longitudinal phase-space tracking Initial distribution OptiM ELEGANT 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25 Yves Roblin Alex Bogacz MATHCAD MATLAB Morteza Aslaninejad Kevin Beard  x /  y = 4.8 mm rad  l   p  z /m  c = 24 mm

8. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 8 Include cavity filling effect on acceleration Get a more accurate initial distribution Design an improved cooling-to-linac section Upgrade analytic cavity phasing – check GPT vs G4beamline Complete linac lattice via tuning solenoids, phasing cavities, & tracking with GPT and G4beamline Linac and RLAs - ‘field map’ tracking 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25 CURRENT EFFORTS:

9. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 9 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25 Injection/Extraction Chicane 1.8 GeV         0.9 GeV 1 m $Lc = 60 cm $angH =18 deg. $BH = 1.6 Tesla 360 15 0 0.5 -0.5 BETA_X&Y[m]DISP_X&Y[m] BETA_XBETA_YDISP_XDISP_Y 2.4 GeV

10. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 10 39.91030 15 0 5 0 BETA_X&Y[m] DISP_X&Y[m] BETA_XBETA_YDISP_XDISP_Y Multi-pass Linac Optics – Bisected Linac 1-pass, 1200-1800 MeV ‘half pass’, 900-1200 MeV initial phase adv/cell 90 deg. scaling quads with energy mirror symmetric quads in the linac quad gradient 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25

11. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 11 Linac-to-Arc – Chromatic Compensation E =1.8 GeV ‘Matching quads’ are invoked No 90 0 phase adv/cell maintained across the ‘junction’ Chromatic corrections needed – two pairs of sextupoles 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25 36.91030 15 0 3 -3 BETA_X&Y[m] DISP_X&Y[m] BETA_XBETA_YDISP_XDISP_Y 720 15 0 3 -3 BETA_X&Y[m]DISP_X&Y[m] BETA_XBETA_YDISP_XDISP_Y

12. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 12 Linac-to-Arc  Chromatic Corrections initial uncorrected two families of sextupoles 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25 36.91030 15 0 3 -3 BETA_X&Y[m] DISP_X&Y[m] BETA_XBETA_YDISP_XDISP_Y 720 15 0 3 -3 BETA_X&Y[m]DISP_X&Y[m] BETA_XBETA_YDISP_XDISP_Y

13. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 13 10 cells in 2 cells out (  out =  in and  out = -  in, matched to the linacs) transition E =1.2 GeV Mirror-symmetric ‘Droplet’ Arc – Optics 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25

14. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 14 ‘Droplet’ Arcs scaling – RLA I i = 1…4E i [GeV]p i /p 1 cell_outcell_inlength [m] Arc11.21 2×22×2 10130 Arc21.83/2 2×32×3 15172 Arc32.42 2×42×4 20214 Arc43.05/22×52×525256 Fixed dipole field: B i =10.5 kGauss Quadrupole strength scaled with momentum: G i = × 0.4 kGauss/cm Arc circumference increases by: (1+1+5) × 6 m = 42 m 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25

15. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 15 ‘Droplet’ Arcs scaling – RLA II i = 1…4E i [GeV]p i /p 1 cell_outcell_inlength [m] Arc14.61 2×22×2 10260 Arc26.63/2 2×32×3 15344 Arc38.62 2×42×4 20428 Arc410.65/22×52×525512 Fixed dipole field: B i = 40.3 kGauss Quadrupole strength scaled with momentum: G i = × 1.5 kGauss/cm Arc circumference increases by: (1+1+5) × 12 m = 84 m 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25

16. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 16 Summary Presently completed Lattices: Pre-accelerator (244 MeV-0.9) + double chicane I RLA I (0.9-3.6 GeV) + double chicane II + RLA II (3.6-12.6 GeV) 4.5 pass linac Droplet Arcs1-4 Chromaticity correction with sextupoles validated via tracking Magnet error lattice sensitivity of Arc lattices Magnet misalignment error analysis shows quite manageable level of orbit distortion for ~1 mm level of magnet misalignment error. Great focusing errors tolerance for the presented lattice  1% of Arc-to-Arc betatron mismatch limit sets the quadrupole field spec at 0.2% 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25

17. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 17 Summary – cont. Piece-wise end-to-end simulation with OptiM/ELEGANT (transport codes) Solenoid linac Injection chicane I RLA I + Injection chicane II + RLA II Currently under study… GPT/G4beamline End-to-end simulation with fringe fields (sol. & rf cav.) Engineer individual active elements (magnets and RF cryo modules) 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25

18. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 18 RLA with Two-Pass FFAG Arcs - Annex 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25   41 m

19. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 19 1.2 GeV/c Linear Optics of Arc 1 Unit Cell 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25 Combined-function bending magnets are used 1.2 GeV/c orbit goes through magnet centers Linear optics controlled by quadrupole gradients in symmetric 3-magnet cell Dispersion compensated in each 3-magnet cell 3-magnet cell Vasiliy Morozov MAD-X (PTC)

20. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 20 sextupole and octupole components 2.4 GeV/c Linear Optics of Arc 1 Unit Cell 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25 Unit cell composed symmetrically of three 3-magnet cells Off-center periodic orbit Orbit offset and dispersion are compensated by symmetrically introducing sextupole and octupole field components in the center magnets of 3-magnet cells symmetric unit cell MAD-X (PTC)

21. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 21 Cell Matching 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25 1.2 GeV/c2.4 GeV/c outward inwardoutward inward

22. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 22 1.8 GeV/c Linear Optics of Arc 2 Unit Cell 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25 Same concept as 1.2 GeV/c linear optics of Arc #1

23. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 23 3.0 GeV/c Linear Optics of Arc 2 Unit Cell 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25 Same concept as 2.4 GeV/c linear optics of Arc #1

24. Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 24 Matching of Linac Optics to Arcs 6-th Plenary Meeting of the IDS-NF, RAL, September 22-25 Adjust linac quads to match arc optics at 1.2, 1.8, 2.4, and 3.0 GeV/c 1 st half pass through linac 0.9 GeV/c 1.2 GeV/c, matched to 1.2 GeV/c optics of arc #1 1 st full pass through linac 1.2 GeV/c 1.8 GeV/c, matched to 1.8 GeV/c optics of arc #2 2 nd full pass through linac 1.8 GeV/c 2.4 GeV/c, matched to 2.4 GeV/c optics of arc #1 Matching to 3.0 GeV/c optics of arc #2 after 3 rd full pass through the linac is in progress