Collimator Wakefield ESA beam test

1
Collimator Wakefield ESA beam test

• SLAC Proposal T-480 (Tenenbaum, Watson et al)
• http//www-project.slac.stanford.edu/ilc/testfac/
  ESA/files/ColWake_TestBeamRequest.pdf
• Many people involved directly, see proposal
• Part of evolving programme of ILC tests at ESA
• http//www.project.slac.stanford.edu/ilc/testfac/
  ESA/esa.html
• Purpose
• Commision/validate CollWake Expt. at ESA
• Additional study of resistive wakes in Cu
• First study of 2-step tapers
• Development of ECHO-3D code (TEMF) for shallow
  tapers/short bunches
• Schedule
• Short run, early Nov. 2005, 4 collimators
• Longer run, mid-late Jan. 2006, 8 collimators
• Status
• Beamline prep., DAQ, BPM set up ongoing
• Test collimators (RAL) sent for fabrication
• Related activity
• Implementation of validated/realistic 3D
  wakefunctions in Merlin
• Collimator damage studies also envisaged at ESA

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Test Beam Responsibilities

• Birmingham (Nigel Watson)
• Programme, analysis, beam test operation
• CCLRC ASTeC (Deepa Angal-Kalinin, Carl Beard,
  Frank Jacksonnew recruit)
• Wakefield simulations, optics design
• Data analysis, instrumentation/signal processing
  support
• Misc. cables (electronics modules t.b.d.?)
• CCLRC ED (Chris Densham, Justin Greenhalgh)
• Collimator insertion design/fabrication
• Lancaster (Jonny Smith, Andre Sopczak, David
  Burton, Robin Tucker, Nick Shales)
• Wakefield simulations and analytic calculations
• Manchester (Roger Barlow, Adam Mercer, German
  Kurevlev)
• Impact of collimator form on emittance dilution
• DESY (Igor Zagorodnov), TEMF TU Darmstadt
  (Wolfgang Mueller, Thomas Weiland)
• Development/validation of 3-d code to model short
  bunch/long structures, optimisation of collimator
  form.
• SLAC (Ray Arnold, Carsten Hast, Doug McCormick,
  Marc Ross and Zen Szalata, Peter Tenenbaum, Mike
  Woods)
• Programme, ESA co-ordinating and infrastructure,
  logistics/beamline support

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ESA beamline layout
Wakefield box

• Measure kick factor using incoming/outgoing beam
  trajectory, scanning collimator gap through beam
• Stage 1, 5 rf cavity BPMs, 1 stripline BPM, 2
  wire scanners
• Wakefield box, proposal for 2 sets of four pairs
  of spoiler jaws
• Each set mounted in separate sandwich to swap
  into WF box
• (relatively) rapid change over, in situ
• 1 week run, Nov. 2005 (t.b.c., going through
  approval process)

4
ESA optical design

• Optical design of A-line for WF expt. by Frank
  Jackson/Deepa A-K.

sy100mm and flat in vicinity of WF box
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Wakefield box
ESA sz 300mm ILC nominal sy 100mm
(Frank/Deepa design)
Magnet mover, y range ?1.4mm, precision 1mm
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Collim. Side view Beam view
1 a324mrad r2.0mm
2 a324mrad r1.4mm
3 a324mrad r1.4mm
4 ap/2rad r4.0mm
a
r1/2 gap
As per last set in Sector 2, commissioning
Extend last set, smaller r, resistive WF in Cu
7mm
cf. same r, tapered
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Collim. Side view Beam view
5 ap/2rad r1.4mm
6 a166mrad r1.4mm
7 a1p/2 rad a2166mrad r14.0mm r21.4mm
8 a1289mrad a2166mrad r1 4.0mm r2 1.4mm
7 mm
cf. collim. 4 smaller r
cf. collim. 2, same r
211mm
31mm
cf. collims. 4 and 6
133mm
cf. collim. 7, and same step in/out earlier data
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Collimator fabrication

• CCLRC ED (Greenhalgh/ODell)
• Required at SLAC 7 Oct.
• Final drawings sent for quote/fabrication Aug.
  10, delivery mid-Sept.