Assorted VTS News Items

1
Assorted VTS News Items

• Project subtasks
• Aseet Mukherjee is designing a thermometry system
  for 9-cell cavities
• RD stage
• Currently planning cryo test of cheaper
  thermometers in ICB (with help from E. Barzi)
• Andrei Lunin has preliminary RF design for a VTS
  input coupler
• Will prepare some plots showing operational range
  in terms of measurement quantities
• Valeri Poloubotko will design the radiation
  shielding lid/movement
• Communications with management
• VTS project progress report for GDE to be
  submitted today
• Only approved tasks appear
• Completed tasks FY06, and plans for remainder
  FY06 and FY07
• Proposal for two additional VTSs (gtFY07) in
  preparation (R. Kephart et al.)
• VTS update to ILC/SRF RD meeting Thursday August
  3
• Plan for MOU addendum with JLab for Tom Powers
  time on RF commissioning
• Plan for electronic logbook (M. Votava) meeting
  today at 2 pm

2
Update of ILC/FNAL RF responsibilities
NB Ralph Pasquinelli is overall responsible
person for ILC/FNAL RF
Generally AD is responsible for RF outside the
cryostat TD is responsible for RF inside
(cables, input couplers, etc.)
3
RF System Design Review

• Charge to the committee
• Assess and comment on all technical aspects of
  the IB1 VTS RF system design, and
• Provide a written report. 
• Committee members Ralph Pasquinelli (chair), Jim
  Steimel, Brian Chase, Chuck Worel, John Reid,
  Wolf-Dietrich Moeller
• Time/date/location/deadlines
• Thursday, August 24, 830-1230
• IB1 Mezzanine conference room
• Background materials to committee by August 17

4
VLCW06 News Gradient task force
Charge to the committee

• The RDB is asked to set up a task force to carry
  out a closely coordinated global execution of the
  work leading to the achievement of the
  accelerating gradient specified in the ILC
  Baseline (BCD)
• A definition of the goals for the cavity
  performance in terms of gradient and yield and a
  plan for achieving them should be proposed by
  this group, which should take account of the
  global resources available and how they may be
  used most rapidly and efficiently.
• The accelerating gradient performance and yield
  should be specified both for an individual 9-cell
  cavity and for an individual cryomodule, and the
  plan should cover the demonstration of this
  performance in both cases.
• The GDE will facilitate the coordination at the
  global level to achieve this vital goal asap.
• Members Hitoshi Hayano, Toshiyasu Higo, Lutz
  Lilje, John Mammosser, Hasan Padamsee, Marc Ross,
  Kenji Saito

5
VLCW06 News Gradient task force

• Make tests more reproducible among labs
• Define tests needed on 9-cells
• complete documentation of prep/test process
• develop common set of parameters
• results more comparable
• Synchronize efforts globally
• model of international coordination of RD
  efforts
• distribute work load

6
VLCW06 News Gradient task force

• Stage 1 Tight-loop (finish mid-2007)
• Start with 20 cavities globally. Carry out the
  full treatment once
• Pick out the best 9 cavities and distribute 3 per
  location. These 9 cavities have a starting
  average gradient and spread.
• Show reproducibility of final process with 3
  best cavities at each location by using the
  tight-loop EP 20um/HPR/test. cavities x 3
  cycles 9 tests per location
• Determine spread and best gradient for final
  treatment process
• Stage 2 improved tight-loop (finish mid 2008)
• Include improvements from the parallel/coupled
  RD program
• Repeat the first stage with the same 9 cavities,
  get smaller spread with higher gradient
• Stage 3 Production Like (start 06)
• Order a large number of cavities starting asap in
  06/07
• According to first assessment, total number of
  cavities in hand by end of 2007 could be 50-60
• Stage 4 Final Production (finish mid-2009)
• Carry out full treatment. Apply best recipe from
  stage 2 to large batch of cavities

7
(Preliminary) set of common tests for 9-cells
VLCW06 News Gradient task force

• Check for hydrogen contamination of the niobium
  material (Q-disease)
• Stay at 100K for 8 hours during cooldown, cool
  down curve should be provided
• As this test significantly extends the testing
  time for some labs, may be omitted after
  confidence has been gained, that the processes
  do not contaminate the niobium with hydrogen.
• Common Q(T) measurement field level about 1 MV/m
  for residual resistance measurement
• p mode as a standard decision on the data, but
  all 9 passband modes have to be measured in order
  to interpret this right
• information of the field flatness has to be added
  (known) some times we see results, hard to
  understand and not to explain with the bad field
  flatness
• Help to localize the problem -    Checks of
  fundamental mode spectrum for possible detuning
  of the field flatness (instead of bead-pull)
• Deformation in field flatness would lead to a
  unusable information from the passband modes
  measurement (if the field flatness is known, it
  could be recalculated)
• Further information to be provided with the data
  above include
• Continuous pumping during test or closed cavity
  vacuum valve
• If closed, pressure before closing valve
•     Cooldown speed
• Temperature difference over cavity during
  cooldown
• Method of low-power processing if necessary
• pulsed or cw
• Coupler type (fixed or variable)
• Recorded quantities Eacc, Qo, Qext, Qtrans,
  Qhom, Pfor, Prefl, Ptrans, Phom, Beta, frequency,
  He bath temperature, X-ray flux, Comments

8
RF Design Review Proposed Agenda
For discussion

• Introduction to VTS (Camille) 15 mins
• Introduction to the team members
• Project scope/progress/plans (copy/update talk
  from July 6 ILC/SRF meeting)
• Infrastructure (Cosmore) 15 mins
• Proposed instrumentation rack location, assembly
  area, etc.
• Drawings with shielding location and movement (as
  known)
• Technical parameters of the measurements (Joe)
  30 mins
• Test plans, testing capacity (including cryo
  capacity)
• Pages 1-5 of May 12 talk, with emphasis on what
  is measured, and why. (motivate the design)
• Required frequency range, phase and amplitude
  stability, input power step size
• Some data from JLab or DESY of measurement
  ranges, as available/relevant
• RF System Engineering Design (Tom) 45 mins
• Schematics
• Data acquisition and control
• RF System Implementation plans (Joe/Ruben) 30
  mins
• Instrumentation list
• Summary/status of purchases
• Project tasks/milestones/resources/schedule

9
RF Design Background Materials

• Test plans, testing capacity