TESLA MEETING 26-28 May 2003 Frascati

1
Working Group Linac techologyintroduction

• Cryomodule design and Assy.
• Tuner issue.
• Danilo Barni
• Danilo.Barni_at_mi.infn.it

2
Cryostat Design Issue

• Actual design - III Generation
• 3 module delivered and assemblied, 2 almost
  installed
• 12m long
• 8 9-cell cavities
• 1 Superconducting QUAD
• Compatible with movable(- 20mm) or quasi-fixed
  coupler(-2mm) by sliding supports (easy
  allignements)
• Lateral 4.2K QUAD (Begin/End of the module)
• ALL drawing for cryostat available in AutoCAD on
  EDMS
• There is no real specification book for
  industry production

3
Cryomodule Assembly and operation

• Experience pointed out during the assembly of
  existing modules (3 generations and other
  specific system)
• Long time between assembly and test of modules gt
  no feedback possible on assembly procedure
• M1 tested after more than 2 years
• M4 will be tested after 2 years
• Module assembly in steps because people involved
  in the assembly also involved in other high-
  priority program (HERA) M3 M4
• Performance of module 1 and 3 worse than
  expected after vertical and horizontal tests
  results not yet reprocidible.
• Leaks in all modules (except of
  Superstructure-module) mainly in RF-feedthrought
  and ceramics but also in the 2K vessel.
• Couplers and coupler assembly often with serious
  problems.
• adjustment of HOM couplers not satisfactory
  problem of communication between rf and
  clean-room stuff (WDM)

4
Cryomodule Assembly and operation

• Open questions,necessary improvements
• TEST of module 4 and 5 to check improvements
  and new technological solution.
• Review of specifications of all components
  materials
• Vessel
• Classification of modules pressure vessel
  regulations safety issues
• Demagnetisation of vacuum vessel necessary?
• Cold Mass
• Number and type of necessary sensors
• Tubing distances to allow use of orbital welding
• Alignment/survey more confortable, more overview
• Tolerable cool-down/warm-up speed

• String
• Tuner (which one / Piezos)
• BPM cleanroom compatible better performance
• He-Tank problems with flanged bottom 2K feed
  line? Problems with introduction of vibrations?
• Specification of cables (especially rf-cables)
• Magnetic shielding no information about exact
  effectiveness, compatibility with tuner
• Cryomodule
• Mechanical vibrations
• Transportation procedure
• Review of vacuum design
• Comparsion of cost of components different
  supplier--- Book of specifications

5
Cryomodule Design Issue

• We need to improve and review really many things
• Everything has to be included and fit in the
  cryomodule for example
• 2K QUAD
• Central QUAD
• New tuner with Piezos
• Coupler
• Heat sink of components (cone, posts, diagnostic)
• Evrerything that will be discussed in this WG.

• INTEGRATION
• We need a good and reliable way to exchange and
  approve drawing coming from different labs and
  industries.
• Definition of procedure for drawing and design
  approve.
• Definition of CAD packages end visualization tool
  to check clereance and interaction regions
• Intensive use of EDMS

6
Tuner design and specs

• At present 2 family of tuner exists
• Lateral Tuner (so called Saclay tuner)
• Lot and lot and lot of experience (since 1997),
  in TTF-I Chechia but most of this experience can
  be moved to other tuner design
• Piezos has been implemented and full tested at
  room temperature and 2K
• All the RD program at DESY on Piezos is carried
  on Saclay Tuner
• BUT
• Longitudinal space consuming
• Too soft for passive Lorentz compensation

• Coaxial Tuner
• 1st prototype never really tested
• Blade tuner.
• Cold tested on superstructure module
• In principle stiff enough for passive lorentz
  compensation.
• Piezo compatibility just on paper-work but never
  tested
• Compatibility with 3rd generation module never
  tested
• New DESY coaxial Tuner
• Easier to integrate with 3rd generation
  cryomodule

7
Tuner Review and RD need

• Which TUNER ???
• Parallel study VS Converge on one solution When
  the decision ?
• To answer we need real specification on
  clearance, stiffness, tuning range
• Integration of Piezo actuator is a MUST. It has
  to be proven for the chosen Tuner.
• Cold Test at least on Chechia.
• Most of the work done on Saclay tuner
  optimisation and components (Motor, harmonic
  driver, ball bearing treatment, control system)
  can be used to design Coaxial tuner.
• Compatibility with the Magnetic Shielding at
  industry level

8
Additional Information

• Leaks in tests - Detlef Reschke
• Flange designs - Kirsten Zapfe
• Cleanroom Quality control - Axel Matheisen
• Coupler Design and Processing - Terry Garvey /
  W.-D. Moeller
• HOM and Pickup - Wolf-Dietrich Moeller
• Experience Module Assembly Rolf Lange
• Active tuning - Lutz Lilje/Stefan Simrock