1. Status of Linac and RLAs – Simulations
Alex Bogacz, Yves Roblin, Jefferson Lab
Kevin Beard, Muons Inc.
Morteza Aslaninejad, Cristian Bontoiu, Jürgen Pozimski Imperial College
Vasiliy Morozov, Old Dominion University
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

2. Linac and RLAs – ‘Big picture’
1st part of this talk
0.6 GeV/pass
3.6 GeV
0.9 GeV
244 MeV
146 m
79 m
2 GeV/pass
264 m
12.6 GeV
2nd part of this talk
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
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

3. RLA Lattice Studies - 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)
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

4. Muon Acceleration Mini-workshop
Feb 2-5, 2010
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

5. Solenoid Linac ( MeV)
6 short cryos
15 MV/m
8 medium cryos
17 MV/m
11 long cryos
1.1 Tesla solenoid
1.4 Tesla solenoid
2.4 Tesla solenoid
Transverse acceptance (normalized): (2.5)2eN = 30 mm rad
Longitudinal acceptance: (2.5)2 sDpsz/mmc = 150 mm
146
Sat Dec 13 22:36: OptiM - MAIN: - D:\IDS\PreLinac\Sol\Linac_sol.opt 12 5
BETA_X&Y[m]
DISP_X&Y[m]
BETA_X
BETA_Y
DISP_X
DISP_Y
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

6. Linac – tracking studies
DONE SO FAR:
shielded two-shell solenoid modeled with POISSON
RF cavities modeled with SUPERFISH, COMSOL, & CST
front-to-end lattice for OptiM (solenoids, dipoles, quadrupoles, & sextupoles)
linac lattice tested in MAD-X
beam tracking using GPT
optical match of linac to cooling channel with one solenoid
beam-loading effects evaluated as negligible
standard for exchanging data files proposed
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

7. Solenoid Model (Superfish)
outer coil
shield
inner coil
‘Soft-edge’ Solenoid
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

8. Two-cell cavity (201 MHz) – COMSOL
Morteza Aslaninejad
Cristian Bontoiu
Jürgen Pozimski
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

9. 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 =
bg = 2.08
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

10. Linac Optics – Beam envelopes
146
Thu Apr 08 13:54: OptiM - MAIN: - C:\Working\IDS\PreLinac\Linac_sol.opt 30
Size_X[cm]
Size_Y[cm]
Ax_bet
Ay_bet
Ax_disp
Ay_disp
Transverse acceptance (normalized): (2.5)2eN = 30 mm rad
Longitudinal acceptance: (2.5)2 sDpsz/mmc = 150 mm
NFMCC Collaboration Meeting, Oxford, MS, January 14, 2010

11. Linac Optics – OptiM vs ELEGANT
146
Sat Dec 13 22:36: OptiM - MAIN: - D:\IDS\PreLinac\Sol\Linac_sol.opt 12 5
BETA_X&Y[m]
DISP_X&Y[m]
BETA_X
BETA_Y
DISP_X
DISP_Y
a = 19.5 cm
a = 19.5 cm
Yves Roblin
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

12. Longitudinal phase-space tracking
MATHCAD
OptiM
Initial distribution
Kevin Beard
Alex Bogacz
ELEGANT
MATLAB
Yves Roblin
Morteza Aslaninejad
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

13. Cooling Channel – Linac Opticsb
B|| a
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

14. GPT Particle Tracking in the Linac
cooling -> upper linac
upper -> middle linac
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

15. Linac and RLAs - ‘field map’ tracking
TO DO NEXT:
Include cavity filling effect on accelaration
Get a more accurate initial distribution
Design an improved cooling-to-linac section
Upgrade analytic cavity phasing – check against GPT
Complete linac lattice via tuning solenoids, phasing cavities, & tracking with GPT
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

16. Linac-to-Arc – Chromatic Compensation
E =1.8 GeV
Wed Jun 11 13:14: OptiM - MAIN: - D:\IDS\Linacs_short\Linac1_fudg.opt 15 3 -3
BETA_X&Y[m]
DISP_X&Y[m]
BETA_X
BETA_Y
DISP_X
DISP_Y 72
Wed Jun 11 14:08: OptiM - MAIN: - D:\IDS\Arcs\Arc2_match.opt
‘Matching quads’ are invoked
No 900 phase adv/cell maintained across the ‘junction’
Chromatic corrections needed – two pairs of sextupoles
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

17. Linac-to-Arc - Chromatic Corrections
initial
uncorrected
two families of sextupoles
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

18. Mirror-symmetric ‘Droplet’ Arc – Optics
130
Tue Jun 10 21:14: OptiM - MAIN: - D:\IDS\Arcs\Arc1.opt 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
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

19. Multi-pass FFAG Arc Basic cell
2 or more passes through the same arc e.g. 5 GeV and 9 GeV
NS-FFAG arc lattice design
Achromatic basic cell with 90 horizontal phase advance
Automatic matching between inward and outward bending cells
Linear optics understood
Need to incorporate sextupole and higher-order field components to accommodate higher momenta
Basic cell
example trajectories
dispersion
Vasiliy Morozov
COSY Infinity
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

20. Multi-pass FFAG Arc 300 60 simple closing of geometry
Vasiliy Morozov
simple closing of geometry
when using similar cells
r = 38.5 meters
300
60
C = 302 meters
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

21. Proposed SDDS Exchange Format
ZGOUBI
ELEGANT
G4beamline
ICOOL
OptiM
COSY-Infinity
MAD-X
GPT …
Kevin Beard
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

22. Summary Critical components of front-end linac modeled
Initial design of the front-end linac simulated
Design matching sections simulated
RLA arc lattice + chromaticity compensation simulated
Putting the pieces together for end-to-end simulations
Multi-pass (2) FFAG Arcs?
IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010