Baseline Lattice Design for PERLE Alex Bogacz Thomas

Baseline Lattice Design for PERLE Alex Bogacz Thomas Jefferson National Accelerator Facility Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 1

Outline What is unique about PERLE? Baseline Design, Lattices PERLE@Orsay - Layout Multi-pass linac Optics in ER mode Arc Optics Architecture ‘Six bend’ arc configuration Switchyard Options Compact ’two step’ Spr/Rec with a second B-com magnet ‘Single step’ vs ’Two step’ Spr/Rec’ configurations Summary and Outlook Thomas Jefferson National Accelerator Facility Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 2

Why is PERLE Unique? PERLE originated as the LHe. C Test Facility is a sub-Ge. V-scale accelerator system invoking a unique combination of parameters, technology, and design choices Very high ‘virtual’ beam power (~10 MW) Moderately high current and bunch charge (20 m. Amp, 500 p. C) Conventional accelerator transport system design Common beam transport for acceleration and recovery Extremely large dynamic range (ratio of full to initial/final energy ~ 100) Multiple passes (3) PERLE offers unique opportunity to controllably study of virtually every effect of interest in the next generation of ERL design Thomas Jefferson National Accelerator Facility Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 3

PERLE@Orsay - Baseline Layout 5 Me. V Top view 5. 5 m 24 m 4 m 10 m DE = 65. 5 Me. V 2: 4: 6 DC = l. RF/2 0. 4 m + 0. 4 m 1: 3: 5 Side view DE = 65. 5 Me. V Thomas Jefferson National Accelerator Facility Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 4

Linac, Cryo-module - Layout SNS-like cryomodule 801. 58 MHz RF, 5 -cell cavity: l = 37. 40 cm Lc = 5 l/2 = 93. 50 cm 1 m 8. 49 Grad = 17. 5 Me. V/m (16. 4 Me. V per cavity) 10 DE= 65. 5 Me. V per Cryo-module 0 BETA_X&Y[m] Linac length: 26 × l. RF 0 BETA_X Re-injection chicane BETA_Y 9. 72 Cryo-module (8. 491 m) Thomas Jefferson National Accelerator Facility Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 5

BETA_X&Y[m] 12 Multi-pass ER Optics 0 Acceleration 0 BETA_X BETA_Y DISP_X E 2 E 1 59. 2518 E 3 E 4 E 6 E 5 BETA_X&Y[m] 12 Einj DISP_Y 0 Deceleration 0 E 6 BETA_X BETA_Y E 5 DISP_X DISP_Y E 4 59. 2518 E 3 E 2 E 1 Einj Thomas Jefferson National Accelerator Facility Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 6

10 2 Arc 6 (5, 4) Optics – ‘Four-Bend’ Lattice 4× 450 bends Qx = 1. 25 Qy = 0. 75 0 -2 DISP_X&Y[m] BETA_X&Y[m] 399 Me. V 0 BETA_X BETA_Y DISP_X triplet: Q 1 Q 2 Q 3 DISP_Y 7. 70429 singlet: Q 4 triplet: Q 3 Q 2 Q 1 Quadrupoles: Dipoles: (91. 2 cm long) B = 1. 2 Tesla Q 1 Q 2 Q 3 L[cm] =10 L[cm] =15 L[cm] =10 G[T/m] = - 23. 6 G[T/m] = 28. 2 G[T/m] = - 22. 4 Q 4 L[cm] =10 G[T/m] = 8. 6 Thomas Jefferson National Accelerator Facility Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 7

Benefits of ‘Six-Bend’ vs ‘Four-Bend’ Arc Smaller bend angle of individual dipoles (300 vs 450) Alleviates strong edge focusing effects of the bends Results in a better balanced optics with smaller alphas Optics more resilient to CSR (micro bunching) Larger number of periods (3 vs 2) – Smaller M 56 variance. Lattices with smaller variation in M 56 generate lower CSR gain*, ideally, lattices that are composed of multiple super-periods, each period being achromatic and isochronous. * Thomas Jefferson National Accelerator Facility Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 8

8 1 Arc 6 (5, 4) Optics – ‘Six-Bend’ Lattice Qx = 1. 75 Qy = 0. 75 6× 300 bends 0 -1 DISP_X&Y[m] BETA_X&Y[m] 399 Me. V 0 BETA_X BETA_Y DISP_X triplet: Q 1 Q 2 Q 3 DISP_Y singlet: Q 0 8. 14398 triplet: Q 4 Q 5 Q 4 singlet: Q 0 triplet: Q 3 Q 2 Q 1 Quadrupoles: Dipoles: (66 cm long) B = 1. 2 Tesla (1. 0 Tesla, 0. 8 Tesla) q. Q 0 L[cm] = 10 G[T/m] = 16. 6 q. Q 1 q. Q 2 q. Q 3 L[cm] = 10 L[cm] = 15 L[cm] = 10 G[T/m] = -30. 1 G[T/m] = 39. 2 G[T/m] = -29. 6 q. Q 4 L[cm] = 10 q. Q 5 National Accelerator L[cm] = 15 Facility Thomas Jefferson Operated by JSA for the U. S. Department of Energy Alex Bogacz G[T/m] = -31. 1 G[T/m] = 40. 6 PERLE Collaboration Meeting, June 3, 2020 9

2 10 M 56 Variance Across Arcs 0 -2 DISP_X&Y[m] BETA_X&Y[m] ‘Four-Bend’ Arc BETA_X BETA_Y DISP_X 7. 704 DISP_Y 2 10 0 0 -2 DISP_X&Y[m] BETA_X&Y[m] ‘Six-Bend’ Arc 0 BETA_X BETA_Y DISP_X DISP_Y 8. 144 Thomas Jefferson National Accelerator Facility Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 10

8 1 Arc 6 (5, 4) Optics – Dispersion/M 56 Control Qx = 1. 75 Qy = 0. 75 6× 300 bends 0 -1 DISP_X&Y[m] BETA_X&Y[m] 399 Me. V 0 BETA_X BETA_Y DISP_X triplet: Q 1 Q 2 Q 3 Q 2 DISP_Y 8. 14398 singlet: Q 0 DQx = 0. 5 triplet: Q 4 Q 5 singlet: Q 0 triplet: Q 3 Q 2 Q 1 Q 2 DQx = 0. 5 Independent Control of Dispersion and M 56 ’Orthogonal Knobs’: Q 2 Q 5 Q 2 Thomas Jefferson National Accelerator Facility Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 11

1 8 Arc 3 (2, 1) Optics – ‘Six-Bend’ Lattice Qx = 1. 75 Qy = 0. 75 6× 300 bends 0 -1 DISP_X&Y[m] BETA_X&Y[m] 202 Me. V 0 BETA_X BETA_Y DISP_X triplet: Q 1 Q 2 Q 3 DISP_Y singlet: Q 0 7. 92569 singlet: Q 0 triplet: Q 4 Q 5 Q 4 triplet: Q 3 Q 2 Q 1 Quadrupoles: Dipoles: (33 cm long) B = 1. 2 Tesla (0. 8 Tesla, 0. 4 Tesla) q. Q 0 L[cm] = 10 G[T/m] = 9. 1 q. Q 2 q. Q 3 L[cm] = 10 L[cm] = 15 L[cm] = 10 G[T/m] = -14. 7 G[T/m] = 16. 6 G[T/m] = -13. 8 q. Q 4 L[cm] = 10 q. Q 5 L[cm] = 15 Facility Thomas Jefferson National Accelerator Operated by JSA for the U. S. Department of Energy Alex Bogacz G[T/m] = -13. 9 G[T/m] = 16. 8 PERLE Collaboration Meeting, June 3, 2020 12

PERLE Magnet Design (dipoles and quads) Two varieties of bends: (66 cm and 33 cm long) 1. 2 Tesla 1. 0 Tesla 0. 8 Tesla 1. 2 Tesla 0. 8 Tesla 0. 4 Accelerator Tesla Facility Thomas Jefferson National Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 13

Switchyard Layout with a Single B-com Energies 1: 2: 3 Arc 2 40 cm Arc 4 Arc 6 Thomas Jefferson National Accelerator Facility Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 14

Switchyard Layout with Two B-coms Energies 1: 2: 3 Arc 2 40 cm Arc 4 Arc 6 Thomas Jefferson National Accelerator Facility Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 15

Switchyard – Pathlength Differences Energies 1: 2: 3 Arc 2 DS 2 -4 = 21. 38 cm Arc 4 DS 4 -6 = 6. 88 cm Arc 6 Thomas Jefferson National Accelerator Facility Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 16

0 -1 DISP_X&Y[m] BETA_X&Y[m] 50 1 ‘Two-step’ vs ‘Single-step’ Spreader 0 BETA_X BETA_Y DISP_X DISP_Y 4. 52 vertical step II 0 -1 DISP_X&Y[m] BETA_X&Y[m] 50 1 vertical step I 0 BETA_X BETA_Y DISP_X DISP_Y 4. 52 vertical step Thomas Jefferson National Accelerator Facility Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 17

‘Two-step’ vs ‘Single-step’ Spreader 1 72 Me. V 0 -1 DISP_X&Y[m] BETA_X&Y[m] 50 L[cm]=10 0 BETA_X BETA_Y DISP_X DISP_Y Q 4 Q 5 Q 6 Q 7 G[T/m] = 10. 50 G[T/m] = -10. 30 G[T/m] = 6. 01 G[T/m] = -3. 34 4. 52 Matching: Q 4 Q 5 Q 6 Q 7 50 0 -1 DISP_X&Y[m] BETA_X&Y[m] 72 Me. V 0 G[T/m] = 1. 96 G[T/m] = 5. 03 G[T/m] = 3. 89 L[cm]=10 1 Disp. supp: Q 1 Q 2 Q 3 BETA_X BETA_Y DISP_X Disp. supp: Q 1 Q 2 Q 3 DISP_Y 4. 52 Q 1 Q 2 Q 3 G[T/m] = -22. 90 G[T/m] = 18. 92 G[T/m] = -24. 44 Q 5 Q 6 Q 7 G[T/m] = -9. 36 G[T/m] = 4. 30 G[T/m] = -2. 49 G[T/m] = 2. 91 Matching: Q 4 Q 5 Q 6 Q 7 Thomas Jefferson National Accelerator Facility Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 18

Summary, Outlook PERLE Baseline Design, Refinements New architecture ‘Six bend’ rather than ‘Four bend’ arc configuration Present ‘Curved Dipole’ design with shorter bends (66 cm, 33 cm) Explored switchyard options Compact ’two step’ Spr/Rec with a second B-com magnet ‘Single step’ vs ’two step’ Spr/Rec’ configurations Next steps …. new Baseline? Thomas Jefferson National Accelerator Facility Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 19

Thank you! Thomas Jefferson National Accelerator Facility Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 20

Special Thanks to: Max Klein Bernhard Holzer and Kevin Andre Thomas Jefferson National Accelerator Facility Operated by JSA for the U. S. Department of Energy Alex Bogacz PERLE Collaboration Meeting, June 3, 2020 21