Berkeley Lab Generic Presentation

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IR Design, Matching to Rings, Chromatic
Corrections
Alex Bogacz
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IRs with 30 mrad crossing angle Layout
Eion 225 GeV Eelectron 9 GeV
80 cm
80 cm
110 cm
260 cm
60 cm
200 cm
50 cm
240 cm
ion
10 cm
300 cm
130 cm
420 cm
electron
IR
180 cm
180 cm
300 cm
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IRs with 30 mrad crossing angle Betas, beam
envelopes
smax 2.6/2.1 mm
Eelectron 9 GeV b 5/5 mm eN 100/4 mm rad
bmax 1.5/20 km
Quads Lcm GkG/cm 50 4.49 60 -3.14 80
3.15 80 -3.05
200 cm
260 cm
240 cm
110 cm
200 cm
260 cm
240 cm
110 cm
smax 3.7/3.3 mm
Eion 225 GeV b 5/5 mm eN 1350/60 mm rad
bmax 2.7/44 km
Quads Lcm GkG/cm 180 24.0 300 -11.3 180
19.7 180 -23.1
300 cm
130 cm
420 cm
160 cm
300 cm
130 cm
420 cm
160 cm
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IR - matching to the Ring
Eion 225 GeV
bx 5 mm by 5 mm
FODO
IR doublet
IR doublet
matching doublet
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Ion Ring (periodic FODO cell) 60 deg. phase
advance
phase adv./cell (Dfx 600, Dfy600)
Arc dipoles E225 GeV Lb170 cm Nin32
Ndip2116Nin gt
214 ang240/Ndip gt 1.121
deg. BPIHrang/(180Lb) gt 86.77
kG RdLb/(PIang/180) gt 8685 cm
Arc quadrupoles Name Lcm GkG/cm qF 100
10.51 qD 100 -10.46
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Layout of one half of the Figure-8 Ion ring with
60 deg. crossing
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Chromatic Compensation Concepts (S. Derbenev)

• Optimize the IR to provide the smallest beta star
  no correcting multipoles
• Use a long section of the beam extension/matching
  for the chromatic compensations (i.e. insertion
  of a Compensating Block (CB) before the IR).
• Design a chicane (snake) CB with a special Optics
  (to introduce dispersion)
• Design a symmetric quadrupole/sextupole lattice
  of the CB self-compensated for emittance and
  squared momentum spread parasitic effects of
  sextupoles
• Compensation for higher order effects (spherical
  aberrations, the third order forces)
• Expansion of the s-Hamiltonian (2-nd, 3-rd, 4-th
  order terms)
• Reduction of tuning equations
• Compensation for aberrations with multipoles

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Chromatic Compensation Block (Chicane/Snake)
R
L
L
R