BDS comparison and positron source

1
BDS comparison and positron source

• A.Seryi
• October 26, 2005

Discussion of BDS and positron source is given in
1 Comment on Decision 8 Positron Source
Type by Tom Himel (editor), Nan Phinney, Tor
Raubenheimer, and Andrei Seryi. The present
file does not repeat the arguments which were
already given in 1 and intended for
illustration to several detailed points.
2

• Sequence in TDR design linac, undulator,
  switchyard and arc bends to offset beam from
  target, magnetic energy spoiler, energy
  collimation, beta-collimation diagnostics,
  final focus
• None of BDS systems are shared between 1st and
  2nd IR
• MES beamline may not need delicate
  instrumentation sensitive to radiations and
  requiring frequent handling

3
Shared diagnostics with laser wires and skew
correction

• In baseline design, the sequence is shared
  diagnostics with laser wires and skew
  corrections, switchyard, polarimeter,
  beta-collimation, energy collimation, final focus
• The diagnostics region has challenging laser wire
  instrumentations and need to have comfortable
  environment for operation and maintenance

4
ILC2005 Beam Switchyard
to dump
skew e
to IR1
to IR2
5
Spare slides

• Details of layout and optics of baseline

6
e-
e
2 mrad (L 3.51 m) dump lines
11 mrad NLC-style Big Bends
IR2 2 mrad
NLC BSY dump lines
20 mrad ILC FF9 (x 4)
IR1 20 mrad
20 mrad (L 3.51 m) dump lines
IP separation 138 m (Z), 21 m (X)
7
ILCFF9 (survivable spoilers)

• Includes
• energy spectrometer chicane
• spoilers
• absorbers
• muon shields
• photon masks
• PCs
• stoppers
• instrumentation
• feedback

8
Yuri-style (NLC) 11 mrad Big Bend polarimeter
chicane
ISR
9
ILC2005 Beam Switchyard
to dump
to IR1
skew e
to IR2