Engineering Test Facility

1
Engineering Test Facility

• What is it and what does it do?

2
What is the ETF?

• An Engineering Test Facility
• The Delay Line Distribution System (DLDS)
  represents a major technical challenge for the
  NLC. The ETF will be used to explore and refine
  the DLDS.
• The Linac structures are spaced approximately 56m
  apart. The ETF will allow the installation
  details of the structures, support girders,
  permanent magnets and ancillary electronics to be
  developed for use in a real linac.
• The later addition of a photoinjector could allow
  the transport and acceleration of beam for
  Wakefield and other physics studies. (C. Bohns
  area)

3
Where is the ETF?

• Meson
• Given the required length (? 400m) for one
  subsection of the main linac, the only
  contiguous, straight tunnel sections available
  were in Meson.
• Meson Polarized (MP) or Meson West (MW)
• MW has the Beams Division Cryogenics department
  located in MW9 and the upstream tunnels are
  scheduled to be used for VLHC string tests.
• MP has CMS activities currently underway in the
  MP9 hall but for the immediate future, this does
  not represent a conflict.
• In its final form, the ETF would stretch from the
  1200 area upstream of the Detector Building to
  nearly the end of the MP9 hall.

4
Why do we need an ETF?

• DLDS
• The DLDS waveguide is an x-band distribution
  system using over-moded waveguide and selective
  mode taps to deliver power to the linac
  structures. Calculations show that the waveguide
  is extremely sensitive to deformation. This will
  require the development of support hardware to
  minimize stresses on the waveguide.
• The high power RF (600MW pulses) precludes the
  use of windows between the accelerating
  structures and the RF waveguide. This implies
  the waveguide will see machine vacuum levels.
  Handling, cleaning, and certifying the waveguide
  are all details needing work.
• How does one connect the waveguide sections?
• The waveguide is currently planned to be 7 inches
  in diameter. The number of connections needed in
  a full length machine would require an extreme
  number of vacuum tight flanges. Alternative
  methods of coupling sections together will be
  explored.

5
What else?

• Structures from Technical Division require
  processing
• The accelerating structures need to be power
  conditioned and measured prior to installation.
  The ETF will be an area where 150MW of RF will be
  available to condition the structures.
• The structures also need to be mounted on support
  girders with auxiliary beam monitoring and
  transport magnets. The ETF will serve as an
  integration test area for these tasks.
• Development of the Control system and Machine
  protection systems can take place here.
• Development of Vacuum system.

6
What are we doing this year?

• In the next few weeks a marching army will
  begin the clean-out of MP-7 and MP-8
• When a mechanical engineer is lured into the ETF,
  work will begin on waveguide supports and section
  welding.
• A major task will be developing the waveguide
  welding scheme. The longest section of waveguide
  is 400m long! With 160 km of waveguide the use
  of flanges is cost prohibitive and could be a
  major detriment to the vacuum system reliability.
• Ralph Pasquinelli and Ding Sun have established
  the following items as goals for the RF work for
  FY01

7
Questions?

• We have a ton of them!