Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 1 Recirculating Linac Acceleration  End-to-end Simulation NuFact'09, Chicago, IL, July 24, 2009

Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 2 Linac and RLAs - Goals 0.6 GeV/pass 3.6 GeV 0.9 GeV 244 MeV 146 m 79 m 2 GeV/pass 264 m 12.6 GeV NuFact'09, Chicago, IL, July 24, 2009 IDS Goals: Define beamlines/lattices for all components Resolve physical interferences, beamline crossings etc Error sensitivity analysis End-to-end simulation (machine acceptance) Component count and costing

Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 3 RLA Acceleration - 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) NuFact'09, Chicago, IL, July 24, 2009

Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 4 Linac-RLA Acceptance NuFact'09, Chicago, IL, July 24, 2009 Initial phase-space after the cooling channel at 220 MeV/c ISS/IDS  rms A = (2.5) 2  normalized emittance:  x /  y mm  rad longitudinal emittance:  l  l   p  z /m  c) momentum spread:   p/p bunch length:  z mm  0.17  412  x,y = 2.74 m  x,y =  = 2.08

Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 5 NuFact'09, Chicago, IL, July 24, 2009 Linear Pre-accelerator – 244 MeV to 909 MeV 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 Transverse acceptance (normalized): (2.5) 2   = 30 mm rad Longitudinal acceptance: (2.5) 2   p  z /m  c  = 150 mm

Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 6 NuFact'09, Chicago, IL, July 24, 2009 ‘Soft-edge’ Solenoid Non-zero aperture - correction due to the finite length of the edge : It introduces axially symmetric edge focusing at each solenoid end: Hard edge solenoid:

Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 7 NuFact'09, Chicago, IL, July 24, 2009 ‘Soft-edge’ Solenoid – Nonlinear Effects Nonlinear focusing term  F ~ O(r 2 ) follows from the scalar potential: Solenoid B-fields Nonlinear focusing included in particle tracking

Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 8 NuFact'09, Chicago, IL, July 24, 2009 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

Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 9 Multi-pass Linac Optics – Bisected Linac 1-pass, MeV ‘half pass’, MeV initial phase adv/cell 90 deg. scaling quads with energy mirror symmetric quads in the linac quad gradient NuFact'09, Chicago, IL, July 24, 2009

Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 10 NuFact'09, Chicago, IL, July 24, 2009 Injection/Extraction Chicane      

Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 11 Pre-accelerator–Chicane–Linac Matching  = 2×10 -5 NuFact'09, Chicago, IL, July 24, 2009

Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 12 NuFact'09, Chicago, IL, July 24, 2009 Pre-accelerator–Chicane–Linac Matching  = 2×10 -5

Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 13 NuFact'09, Chicago, IL, July 24, 2009 Injection-to–Linac – Chromatic Corrections uncorrected one family of sextupoles two families of sextupoles  xy = 180 0

Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 14 NuFact'09, Chicago, IL, July 24, 2009 Linac ½-to-Arc1 – Beta Match E =1.2 GeV Already matched ‘by design’ 90 0 phase adv/cell maintained across the ‘junction’ No chromatic corrections needed

Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 15 NuFact'09, Chicago, IL, July 24, 2009 Linac1-to-Arc2 – 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

Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 16 NuFact'09, Chicago, IL, July 24, 2009 Linac1-to-Arc2 - Chromatic Corrections initial uncorrected two families of sextupoles

Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 17 NuFact'09, Chicago, IL, July 24, cells in 2 cells out (  out =  in and  out = -  in, matched to the linacs) transition E =1.2 GeV Mirror-symmetric ‘Droplet’ Arc – Optics

Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 18 Adiabatic compression in the RLA  off-crest acceleration in the linac + non zero momentum compaction in the arcs (M 56 ~6 m) Longitudinal Compression in the RLA NuFact'09, Chicago, IL, July 24, 2009

Operated by JSA for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility Alex Bogacz 19 Summary Presently completed Lattices: Pre-accelerator (244 MeV-0.9) + injection double chicane RLA I ( GeV) and RLA II ( GeV) 4.5 pass linac Droplet Arcs1-4 Chromaticity correction with sextupoles validated via tracking Piece-wise end-to-end simulation with OptiM (transport code) Solenoid linac Injection chicane RLA I Still to do… end-to-end simulation with fringe fields (sol. & rf cav.) NuFact'09, Chicago, IL, July 24, 2009