Extended Coupling Correction and Emittance Diagnostic Section for

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Extended Coupling Correction and Emittance
Diagnostic Section for optimal ATF2
Coupling Correction / Emittance Diagnostics
FONT
nBPM (SLAC)
nBPM (KEK)
Compton / laserwire
Existing ATF Extraction Line
ODR
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(No Transcript)
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FF Optics Modifications

• From Tauchi-sans email (bds 117 June 2, 2005)
• 5. Optics modifications
• (1) concentrate on "optimal" design (straight)
  done
• (2) change bends from sector bends to
  rectangular done
• (3) use 0.8 m bends (as used in ATF) instead of
  1 m for better field stability and more space
  done
• (4) remove octupoles (do not use them, and they
  are tight) done (OC0 removed OC1 moved away
  from SF1)
• (5) extend diagnostics section (use up to 10 m
  additional space) done
• (6) QM14 is the strongest quad, and is close to
  max field of BT quads, need to check if its
  strength can be reduced by reoptimizing the
  matching section done (QM14K1L -1.1 m-1)

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ßx,y 4,0.1 mm
?L 7.1 m (w.r.t. baseline)
30 cm offset
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Assembly Hall
optimal
baseline
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-1
1
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Coupling Correction

• ideally
• correction section with 4 independent skew
  quadrupoles, followed by
• 2D (4 wire scanner) emittance measurement section
• optics for orthogonal control of the 4 coupling
  phases
• minimize ey once with each skew quadrupole
• in present ATF extraction line
• non-optimal optics in EXT straight section
• wire scanners and skew quads interspersed
• each wire scanner has x, y, and u/v (small
  angle, 10) wires
• one attempt at full 4D beam matrix measurement
  and correction was inconclusive1

1 See http//atfweb.kek.jp/atf/Reports/ATF-99-01.p
df
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Ideal skew correction / e diagnostic section
SQ
SQ
SQ
SQ
WS
WS
WS
WS
x y
90 90
180 90
90 90
45 45
45 45
45 45
See http//www.slac.stanford.edu/cgi-wrap/getdoc/
slac-pub-8581.pdf
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SQ
SQ
SQ
SQ
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
1.3
1.3
1.3
1.3
WS
WS
WS
WS
WS
x y
90 90
180 90
90 90
33 57
57 33
33 57
57 33
59.2 10.8
108.0 5.9
59.2 10.8
108.0 5.9
59.2 10.8
s (µm)
For MAD files see http//www.slac.stanford.edu/m
dw/ATF2/optimal
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new quadrupole (between QF3X and BH1X.3)
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A Drift e-Diagnostic Section
from Paul Emma
b
s
L
w1
w2
w3
3 wire scanners (or profile monitors)
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x y
smin 3 µm
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Continuing Work

• optimize system bandwidth and performance
• add BPMs and dipole correctors
• simulate steering and dispersion/coupling
  correction with machine/diagnostic errors
• verify what space is needed for diagnostic
  equipment in chicane
• investigate drift ediagnostic section
• writeup for ATF2 proposal document