MDI panel meeting minutes
May 31, 2006 (Wed) 23h (JST)

+81-29-877-1214 for only voice
KEK gate keeper ID number 31110

Attendance: Omori, Tauchi, Bambade, Burrows, Seryi,
Busser, Kozanecki, Markiewicz, Lohmann, Yamamoto,
Torrence, Sugiyama (observer)

1. gamma-gamma upgrade option

Andrei explained the current status of the change
control submitted to CCB. It was submitted since
the gamma-gamma option is in the scope document and
has implications on the design at the BCD level.
However, CCB has decided to return the change-control
request to the submitter mainly due to the lack of
concerted efforts on accelerator, BDS, and detector
issues related to the gamma-gamma option.

The MDI panel accept the decision by CCB since there
is not enough resources at this time when all resources
are focused on RDR. The panel stresses, however, that
the issue of gamma-gamma option continues to exist, and
it needs to be dealt with well-organized resources, e.g.
when RDR is completed.

Meanwhile, works related to gamma-gamma should be
done whenever possible. It was suggested that each
detector concept team should consider the gamma-gamma
upgrade option and such discussion should be in
DCR to be written at the end of this year.

2. Experimental hall issues.

The goal is to provide enough information so that
the experimental hall section of BCD can be
written. Two things seem certain:

a. Beam commissioning and detector assembly need to be
able to proceed in parallel.

This means that the access shaft should not be right on
top of the beamline.

b. The hall should be designed such that any of the three
detector concepts can fit. Namely, it should accomodate

The current default is 72x32x30m hall for each of the two

Also, it was suggested that,
(i) the detector concepts should take a serious look at the
CERN CMS approach (surface assembly, very large assembled pieces
lowered into the pit)
(ii) the detector concepts should document not only the cavern
requirements associated with the construction, but also those linked
to access and maintenance once construction is completed?.

There are more questions to be answered by detector conceot
teams. Andrei will contact Jean-Luc to make a list of
questions that are not answered at present. It will be
handed to each detector concept team for them to reply.

3. DID, anti-DID issues

Philip expressed a concern that if DID/anti-DID to be
'tuned' to varying beam conditions, then the TPC
calibration will become impossible.
For precision physics we will need to have large datasets
common to all physics teams and calibration efforts.
Therefore, a procedure will have to be followed to optimise
this correction as a compromise between the different conflicting
requirements (arising from physics, backgrounds, beam conditions...)
during the commissioning. Once such a setting has been found, it will
have to be kept stable for a long enough time so that a common dataset
with maximal statistics be available for both the physics analys
The panel generallyagreed with his point, and each detector concept
shouldassess the amount of time and effort needed for the
calibration of TPC for one setting of the field.
(According to Ron Settles who could not attend the
meeting, such calibration can be done, but details
still need to be worked out.)

4. Other issues

Tom pointed out that the magnet envelope (or stay clear)
needs to be worked out for each detector concept including
the compensating solenoid (for different crossing
angles). A preliminary study was done for
SiD, and it became clear that this is one missing MDI

There will be a MDI panel meeting at Vancouver. We may
also have one more before Vancouver if needed.