Muon RLA - Design Status and New Options Alex Bogacz Vasiliy Morozov, Yves Roblin, Jefferson Lab Kevin Beard, Muons Inc. MAP Winter Meeting, Jefferson Lab, March 2, 2011

Linac and RLAs - IDS IDS Goals: RLA with FFAG Arcs 244 MeV 0.6 GeV/pass 3.6 GeV 0.9 GeV 146 m 79 m 2 GeV/pass 264 m 12.6 GeV 79 m Vasiliy Morozov IDS Goals: Define beamlines/lattices for all components Matrix based end-to-end simulation (machine acceptance) (OptiM) Field map based end-to-end simulation: ELEGANT, GPT and G4Beamline Error sensitivity analysis Component count and costing Two regular droplet arcs replaced by one two-pass FFAG arc K. Beard Y. Roblin C. Bontoui MAP Winter Meeting, Jefferson Lab, March 2, 2011

Pre-Linac - Longitudinal phase-space Initial distribution ex/ey = 4.8 mm rad el = sDp sz/mmc = 24 mm ELEGANT (Fieldmap) OptiM (Matrix) MAP Winter Meeting, Jefferson Lab, March 2, 2011

Injection/Extraction Chicane $Lc = 60 cm $angH = 9 deg. $BH = 10.2 kGauss $Lc = 60 cm $angV = 2 deg. $BV = 4.7 kGauss m+ m+ m- m- 0.9 GeV 50 cm 1.7 m 2.1 GeV 1.5 GeV 30 1 -1 BETA_X&Y[m] DISP_X&Y[m] BETA_X BETA_Y DISP_X DISP_Y FODO lattice: 900/1200 (h/v) betatron phase adv. per cell Double achromat Optics H -H V -V 3 cells 4 cells MAP Winter Meeting, Jefferson Lab, March 2, 2011

Chicane - Double Achromat Optics 30 0.5 PHASE_X&Y Q_X Q_Y Dfx = 2p Dfy = 2p betatron phase 30 1 -1 BETA_X&Y[m] DISP_X&Y[m] BETA_X BETA_Y DISP_X DISP_Y Double achromat Optics FODO quads: L[cm] = 50 F: G[kG/cm] = 0.322 D: G[kG/cm] = -0.364 sextupole pair to correct vert. emittance dilution H -H V -V 3 cells 4 cells MAP Winter Meeting, Jefferson Lab, March 2, 2011

Multi-pass Linac Optics – Bisected Linac ‘half pass’ , 900-1200 MeV initial phase adv/cell 90 deg. scaling quads with energy 39.9103 15 5 BETA_X&Y[m] DISP_X&Y[m] BETA_X BETA_Y DISP_X DISP_Y quad gradient 1-pass, 1200-1800 MeV mirror symmetric quads in the linac 78.9103 15 5 BETA_X&Y[m] DISP_X&Y[m] BETA_X BETA_Y DISP_X DISP_Y quad gradient MAP Winter Meeting, Jefferson Lab, March 2, 2011

Multi-pass bi-sected linac Optics 389.302 30 5 BETA_X&Y[m] DISP_X&Y[m] BETA_X BETA_Y DISP_X DISP_Y 1.2 GeV 0.9 GeV 3.0 GeV 2.4 GeV 1.8 GeV 3.6 GeV Arc 4 Arc 3 Arc 2 Arc 1 bx = 3.2 m by = 6.0 m ax =-1.1 ay =1.5 bx,y → bx,y axy → - axy bx = 6.3 m by = 7.9 m ax =-1.2 ay =1.3 bx = 7.9 m by = 8.7 m ax =-0.8 ay =1.3 bx = 13.0 m by = 14.4 m ax =-1.2 ay =1.5 quad grad. length MAP Winter Meeting, Jefferson Lab, March 2, 2011

Linac-to-Arc – Chromatic Compensation E =1.8 GeV 72 15 3 -3 BETA_X&Y[m] DISP_X&Y[m] BETA_X BETA_Y DISP_X DISP_Y 15 3 BETA_X&Y[m] DISP_X&Y[m] -3 BETA_X BETA_Y DISP_X DISP_Y 36.9103 ‘Matching quads’ are invoked No 900 phase adv/cell maintained across the ‘junction’ Chromatic corrections needed – two pairs of sextupoles MAP Winter Meeting, Jefferson Lab, March 2, 2011

Linac-to-Arc - Chromatic Corrections initial uncorrected two families of sextupoles 36.9103 15 3 -3 BETA_X&Y[m] DISP_X&Y[m] BETA_X BETA_Y DISP_X DISP_Y 72 MAP Winter Meeting, Jefferson Lab, March 2, 2011

Mirror-symmetric ‘Droplet’ Arc – Optics 130 15 3 -3 BETA_X&Y[m] DISP_X&Y[m] BETA_X BETA_Y DISP_X DISP_Y E =1.2 GeV (bout = bin and aout = -ain , matched to the linacs) 2 cells out transition 2 cells out 10 cells in transition MAP Winter Meeting, Jefferson Lab, March 2, 2011

Alternative multi-pass linac Optics 389.302 90 5 BETA_X&Y[m] DISP_X&Y[m] BETA_X BETA_Y DISP_X DISP_Y 1.2 GeV 0.9 GeV 3.0 GeV 2.4 GeV 1.8 GeV 3.6 GeV Arc 1 Arc 4 Arc 3 Arc 2 bx = 3.2 m by = 6.0 m ax =-1.1 ay =1.5 bx,y → bx,y axy → - axy quad grad. length MAP Winter Meeting, Jefferson Lab, March 2, 2011

Arcs ‘Crossing’ - Vertical Bypass m+ m- 42 30 2 -2 BETA_X&Y[m] DISP_X&Y[m] BETA_X BETA_Y DISP_X DISP_Y 4 vertical bends: B = 1 Tesla L = 10 cm E = 1.2. GeV Dy = 25 cm V -V 4 cells (900 FODO) MAP Winter Meeting, Jefferson Lab, March 2, 2011

‘Droplet’ Arcs scaling – RLA I Ei [GeV] pi/p1 cell_out cell_in length [m] Arc1 1.2 1 2×2 10 130 Arc2 1.8 1.43 2×3 15 172 Arc3 2.4 1.87 2×4 20 214 Arc4 3.0 2.30 2×5 25 256 Fixed dipole field: Bi =10.5 kGauss Quadrupole strength scaled with momentum: Gi = × 0.4 kGauss/cm Arc circumference increases by: (1+1+5) × 6 m = 42 m MAP Winter Meeting, Jefferson Lab, March 2, 2011

‘Droplet’ Arcs scaling – RLA II Ei [GeV] pi/p1 cell_out cell_in length [m] Arc1 4.6 1 2×2 10 260 Arc2 6.6 1.435 2×3 15 344 Arc3 8.6 1.870 2×4 20 428 Arc4 10.6 2.305 2×5 25 512 Fixed dipole field: Bi = 40.3 kGauss Quadrupole strength scaled with momentum: Gi = × 1.5 kGauss/cm Arc circumference increases by: (1+1+5) × 12 m = 84 m MAP Winter Meeting, Jefferson Lab, March 2, 2011

Component Count beamline RF cavities solenoids dipoles quads sext 1-cell 2-cell pre-accelerator 6 62 25 inj-chic I 8+3 16 3 RLA I linac 24 26 arc1 35 43 arc2 49 57 8 arc3 63 71 arc4 77 85 inj-chic II RLA II 80 42 Lambertson 1 MAP Winter Meeting, Jefferson Lab, March 2, 2011

Summary Piece-wise end-to-end simulation with OptiM/ELEGANT (transport codes) Solenoid linac Injection chicane I (new more compact design) RLA I + Injection chicane II + RLA II Chromaticity correction with sextupoles validated via tracking Alternative multi-pass linac optics Currently under study… GPT/G4beamline End-to-end simulation with fringe fields (sol. & rf cav.) Engineer individual active elements (magnets and RF cryo modules) MAP Winter Meeting, Jefferson Lab, March 2, 2011

Backup slides MAP Winter Meeting, Jefferson Lab, March 2, 2011

Initial phase-space after the cooling channel at 220 MeV/c Linac-RLA Acceptance Initial phase-space after the cooling channel at 220 MeV/c ISS/IDS erms A = (2.5)2 e normalized emittance: ex/ey mmrad 4.8 30 longitudinal emittance: el (el = sDp sz/mmc) momentum spread: sDp/p bunch length: sz mm 24 0.07 165 150 0.17 412 bx,y = 2.74 m ax,y = -0.356 bg = 2.08 MAP Winter Meeting, Jefferson Lab, March 2, 2011