NLC - The Next Linear Collider Paul Czarapata Engineering Test Facility What is it and what does it do?

Paul Czarapata Slide 2 NLC - The Next Linear Collider 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)

Paul Czarapata Slide 3 NLC - The Next Linear Collider 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.

Paul Czarapata Slide 4 NLC - The Next Linear Collider 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.

Paul Czarapata Slide 5 NLC - The Next Linear Collider 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.

Paul Czarapata Slide 6 NLC - The Next Linear Collider 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:

Paul Czarapata Slide 7 NLC - The Next Linear Collider Questions? We have a ton of them!