[Ext-GDE-97] Remarks on CCR#23 from MDI and WWS?

[N.Toge <toge@xxxxxxxxxxxx>]

Dear Jim, Francois, Hitoshi,

Nobu Toge from CCB/ILC-GDE here.

I am writing to ask your comments and remarks as leading
members of WWS and/or MDI with regards to CCR#23 (one-IP,
push+pull) that CCB received from A.Seryi today.

Information is available at

   http://lcdev.kek.jp/ML/PubCCB/msg00130.html

with links to related documents and reports.

What CCB is particularly interested in is your assessment
on the physics research potential from the luminosity
availability stand-point.

a. In case of two-IR, although an instantaneous switch-over
   is not a possibility, it is expected possible to
   switch delivery of colliding beams from one IR to the
   other within a time scale compatible to ~ one day.

b. In case of single-IR, the detectors have to rolle-out
   and in, and all the associated re-plumbing and interlock
   rewiring etc are needed. So the time-scale of the switch-over 
   could be substantially longer unless careful planning
   is made with well-prepared hardware designs.

The report "Push-Pull Interaction Region Issues" by M.Breidenbach 
and B. Richter Sept. 29, 2006, as referenced by CCR#23 indicates
that the switch-over and the beam recovery with case b could
be done within 24hrs.

CCB in particular would like to understand 

- if the report above (feasibility of 24hr turn-around) has 
  a concurrence of relevant parties in HEP community around ILC

  then,

- how your concurrence (or other) on CCR#24 is contingent on 
  the statement given by this Breidenbach-Richter report

CCR description document by BDS AG leaders refers to "the meaning of
push-pull" by M.Breidenbach. CCB would like to access this document
as soon as it becomes available, too.

Also CCB would be interested to hear additional remarks or comments,
if there are any, on this CCR from representatives of WWS, MDI as
well as representatives of SiD, LDS and GLD.

CCB would appreciate hearing your response (if possible)

    before the end of Tuesday, Dec. 5, 2006, PST.

Thank you, in advance, for your attention and help on this matter.

Sincerely,

- Nobu Toge (KEK, Accelerator Lab)
  email: toge@xxxxxxxxxxxx
  voice: +81-29-864-5224
  fax:   +81-29-864-3182