1. “Medium Term”: VFAT2 + SRS readout system
Goals :
Lab set-ups for GEM development using VFAT2
To be used in test beams.
Allows detector studies using both VFAT2 and APV simultaneously.
24 new wafers of VFAT2 ordered in 2011.
H.Muller, S.Martoiu

2. VFAT2 hybrids Readout & power options: HDMI cable Plug-in to GEM PCB
Short hybrid version to be used with VFAT2_GEM

3. CMS GEM chambers 10x3. One GEM chamber = 30 VFATs,
Eta partitions 1 2 3 .
Phi Columns
Segments
(ie Segment A3)
A B C
GEM chamber segmentation
FE ASIC
1 FE ASIC / segment
One GEM chamber = 30 VFATs,
A Super-chamber = double sided GEM chamber (hence 60 VFATs).
We wish to be able to read, two Super-chambers (hence 120 VFATs).

4. VFAT2 + SRS Goals Read two super chambers using SRS.
Purpose …….… lab measurements of GEMs at CERN
Possible use in test beams
Enable external labs to purchase VFAT2 plus DAQ system
Time scale : September 2012 : New VFAT2 hybrid testing.
SRS system to read one chamber 1 crate + 4 FEC cards.
Q : SRS system to read 2 super chambers (Q3 order).
1 additional crate + 12 FEC cards.

5. CMS Needs 1st run (Sept) Source 2nd run (Q4 12) Total Crates 1
Prisma/CERN Store 2
FEC 4 12 16
Adapter cards1
Prototype (CERN/RD51)
Prisma/CERN Store(?)
Hybrids (VFAT)1 30 90
CERN Store
120
1Under design. First prototypes due in September

6. Future GEM with integrated GEM PCB
Evolution of GEM PCB
Present GEM chamber plus VFAT2 totem hybrids
Future GEM with integrated GEM PCB
Evolution of GEM PCB:
Present : Power and signals delivered to VFAT via flat cables.
Near Future : GEM PCB to carry power to new VFAT2 hybrids, HDMI cables to carry signals.
Future : GEM PCB to carry power and signals, no cables on GEM, plug in hybrids with glob top VFATs.