1. Update: EMC R&D
David Hitlin
SuperB R&D Meeting
September 25, 2008

2. Developments since Elba
There were no meetings during June, July, August
(Bi-weekly) meetings resumed last week
Next meeting Tuesday, Sept. 30, then resume alternate Wednesdays at 8:30AM PST/5:30PM ECT
Good news on the crystal geometry (Zhu)
Good news on the beam test module (Asner)
Progress on fast simulation (Cheng)

3. Forward endcap geometry
We have been looking at two classes of crystal arrangement
Vary crystal sizes with radius, starting with a front face dimension at small radius of ~ 1 Molière radius (à la BABAR)
Use a single crystal size (à la CMS)
There advantages and disadvantages to each geometry
There is, however, an important constraint on both approaches

4. Candidate endcap crystal geometry
Constraint: a 60mm diameter SIPAT boule must yield two crystals
Stefano Germani

5. Cartesian endcap geometry (Frank Porter)
All crystals are identical

6. Boule constraint There is an important constraint
The SIPAT boule diameter is 60 mm
To retrieve two crystals per boule with a back end as large as 25x25 mm requires the two crystals to be in opposite orientation
In the Czochralski process, there is unavoidably a gradient in the dopant (Ce, Y) along the crystal length
There is evidence that light output depends on Ce concentration
Ren-yuan Zhu has been investigating this question in detail

15. This allows a yield of two crystals per SIPAT boule, which has a significant impact on the price/cc

16. Beam Test
A good solution to the “catcher crystal” problem has presented itself
INFN will provide €50K for LYSO crystals
A proposal to DOE for Advanced Detector Research funds is in preparation
A scintillating fiber/tile readout concept was presented at Elba by Gerald Eigen
Appears to be a cost-effective, well-performing approach with geometric flexibility in a difficult space
Many details to be worked out
Readout device (SiPM ??) – neutron radiation dose is a question
Rear endcap

17. 5x5 Projective LYSO array with CsI(Tl) surround
A 7x7 array is best, but it can be approximated by a 5x5 array surrounded by CsI(Tl) to catch the outer few percent of shower
16 radiation-damaged projective BABAR CsI(Tl) crystals may be available
New: 12 CLEO-II non-projective CsI(Tl) crystals may available
(four PD/crystal readout)
CMS APD readout module
5mmx5mm APD
(10x10mm APDs are now available)