Present: Cooper, Demarteau, Graham, Grillo, Haller, Jaros, Kenney,
Maruyama, Partridge

Please send any comments/corrections to the whole group. 

1. Next Meeting: Friday, Dec 18, at 9AM PST.

2. We reviewed the current ideas for the tracker. Takashi noted that
innermost strips (i.e.closest to the beam) have few per cent occupancies
from hi energy electrons, which at 40 MHz translates into 30 Mrad doses
in a month! See attached slides.

  The current tracker fits within good field region of the first
analyzing magnet, a space of 20 x 20 x 100 cm**3. There are 6 planes of
si so far: x,y close to the target; x,y farther (for vertexing), and two
more planes for additional momentum constraint. We know this doesn't
pattern recognize. Rich and Matt are working on that with a full
lcsimulation. In particular, we don't know yet if there are sensors at
small stereo angles to resolve ambiguities. Note that multiple coulomb
scattering is already limiting our momentum resolution and vertexing
resolution and invariant mass resolution, with just the 6 planes of
detector (see attachment). 

  Takashi and others are still optimizing the layout. For practical
purposes of imagining how the detectors are supported, cooled, readout
and so on, the present picture is adequate, but its details will change.

3. Marcel talked about the D0 sensors which were described in a previous
attachement. They are 10 x 4 cm, 60 micron pitch with intermediate
strips (not read out), 320 microns thick. Fermilab has 700 sensors from
Hamamatsu, all in very good shape, and expects to be able to fill our
needs.

Some questions arose in discussion:
A. Can snesors be thinned?
B. How must they be cooled? Can we minimize cooling material in the
fiducial region?
C. Can sensors operate in helium gas or in vacuum? (The question comes
up because the primary 100 nA beam passes within 5 mm of these
detectors. It may kick up a serious backgrounds in passing through air)
D. How much radiation can they take? What happens when just a few mm of
strips are affected by very High dose?

4. Alex talked about the ATLAS tracker amp/readout chips. UCSC has ~4000
ABCD chips, each of which has two bad channels (of 128), but many of
which are therefore available to us gratis. They have been described in
pubs sent around earlier. They have binary readout, work at 40 MHz, have
3 microsecond latency for readout, and can support a trigger rate up to
100 kHz. Noise occupancy is low with proper threshold setting, order
10**-4.

The question of availability of hybrids came up. Alex will see if any
can be scrounged for some preliminary tests, and if the present design
can be copied for a new production run. We assume readout chips will be
positioned near to the pole faces for strips perpendicular to the poles;
and benignly sit off to the edges for strips parallel to the pole faces
(no tight space constraints there). Neither should see high radiation
dosages.

The bad channels  are due to excess noise or a stuck bint in the
pipeline.

The sensor pitch is very close to the 50 micron pitch of the ABCD chip.

Some questions re readout:
1. What is resolution with binary readout? Worse than width/ root 12? 
2. What fraction of double hits?
3. Are some ATLAS hybrids available for tests with sensor?
4. Who will develop and build hybrids? On kapton? PC?

5. Gunter spoke briefly about plans for readout. Systems in use at LCLS
can transfer data at the needed
rates. He'll present architecture ideas soon. All agreed this was a
reasonable direction for DAQ.

6. Resources and schedule.
John said he hopes we can develop a proposal by Feb 2010, including a
good conceptual design of the microstrip system and readout. The hope is
to build the experiment in 2010, and have it ready by spring 2011. This
would give it one year in the beam before Jlab shuts down in May 2012
for its upgrade to 12 GeV. Our job in the proposal will be to provide
conceptual designs, estimates of time needed for fab and testing and
assembly, and estimation of costs. Resources for now are some minor
design funds at SLAC.
We should explore extra support at Fermilab and Jlab once  we understand
what we'd like contributions to be. Basic expenses, besides manpower,
are for DAQ, hybrid, and magnets. The experiment also needs an ecal
trigger, and muon id, which haven't received much attention yet.