CURVED LINAC ILC BCD LATTICE

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CURVED LINAC ILC BCD LATTICE
Orbit at the YCORs (mm)
Normalized Emittance (nm)
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CURVED LINAC ILC BCD LATTICE
Yp - dispersion
Y dispersion (m)
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• Dispersion MATCHED steering (for straight linac,
  its Dispersion FREE steering)
• Do the 11 steering in the whole Linac
• Do the DMS from the 8th BPM onwards
• 1st 7 BPMs are assumed to have smaller offset
  30 um.
• Minimized orbit yb_dfs_b - yb_dfs_a -
  design_diff, where
• yb_dfs_b is the BPM readings for off energy
  orbit, i.e., for E2 Eo DE
• yb_dfs_a is the BPM readings for on energy orbit,
  i.e., for E1 Eo
• design_diff is the orbit difference coming from
  design dispersion h(E2-E1)/E1
• and h is the machines design dispersion

ab initio (Nominal) installation conditions
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CURVED LINAC ILC BCD LATTICE 50 seeds
Normalized emittance (nm)
DMS projected 50 seeds and mean
DMS corrected 50 seeds and mean
DMS mean
11 mean
projected
projected
corrected
corrected
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STRAIGHT LINAC ILC BCD LATTICE 50 seeds
Normalized emittance (nm)
DMS
11 mean
DMS mean
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CURVED vs. STRAIGHT LINAC ILC BCD LATTICE 50
seeds Normalized emittance (nm)
CURVED
STRAIGHT
DMS
DFS
Mean 7.4 0.5 nm
Mean 5.0 0.4 nm
90 11.8 nm
90 8.7 nm
corrected
11
11
Mean 211 25 nm
Mean 232 28 nm
90 442 nm
90 436 nm
corrected
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CURVED vs. STRAIGHT LINAC ILC BCD LATTICE 50
seeds Mean projected Normalized emittance
DMS
CURVED corrected
STRAIGHT
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Decomposition in terms of different
components Dispersion - Quad offset, BPM offset,
Cavity pitch, CM pitch, No wakes, ELOSS on Wakes
- Cavity offset, CM offset , Wakes
on Quadroll - Quad roll only BPM resolution
1 micron
CURVED
STRAIGHT
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Dispersion Matched Steering Sensitivity
studies Keeping all other misalignments at the
nominal values, just vary one particular offset
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Mean
90
11
Mean
90