New BDS Production Deck BDS9801

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New BDS Production Deck -- BDS9801

• PT, 26-October-1998

Path that ever Promise made Desire dream
dissolve and fade
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1. Magnet Revisions
Why Revise any of the Magnets?

• Vacuum Magnet bore gt 8 mm
• Transitions mixed 1.2cm/1.0cm quad bores risky
• Uniformity of Quad Apertures

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Changed quads/sexts to minimum 1.2 cm full bore

• 40 quads with Bpole gt 6.7 kG (20 in final focus,
  3 cm full bore)
• 6 quads with Bpole 10-11 kG, all in
  pre-collimation diagnositcs
• Bends need no revision
• Sexts 2 with Bpole gt 7 kG -- longer?

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2. IP Switch/Separator

• IP separation gt 200 m in z
• One beamline (Short BDS) bends at IPSW, other
  goes straight to second IPSW module
• IPSW 100 m, so need 100-200 m Separator beamline

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Design Constraints of IP Separator Design

• Both beamlines pass through IP Switch 1 -- for
  IP 2, bends are turned off Degaussed!
• IP 2 line should contain second IP Switch for
  energy diagnostics
• Dfx,y np between 2 lines (collimation)

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IP Separator Solution

• Both beamlines pass through IPSW1
• IPSW quad 2 post-IPSW quads common (move
  cms)
• Long BDS contains 5 new quads, 2nd IP SW 2nd
  match into Big Bend

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IP Separator Soln (contd)

• Total added phase advance 2p in x and y, Dz
  287 meters
• A few quads and bends in short BDS must be moved
  out of way
• Optically solution is marginal (Dsx,Dsy)
  (0.5,2) --chromaticity?

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Conclusions (good news)

• New BDS Deck (BDS9801) almost ready for release
• Quad bores expanded
• IP Separator Beamline included

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Conclusions (bad news)

• Many quads too strong for 1.5 TeV CM some bad
  for 1 TeV
• IP separator design requires several shifts for
  IP switchover
• Separator chromaticity requires IPSW/BB sexts
  (needed anyway)

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Conclusions (ugly news)

• Need revised collimation region (no passive
  survival)
• Need IPSW/BB sextupoles
• Need to try longer, weaker IR quads