1. EMC Barrel Electronics Status
Valerio Bocci INFN Roma
2nd SuperB Collaboration INFN-LNF Dec 2011 Valerio Bocci 1

2. Location of the Front End electronics in the EMC barrel
Data Transmission
Unit (ex IOB)
40 DTU
Slac Visit
25 Nov 2011
40 DTU
2nd SuperB Collaboration INFN-LNF Dec 2011 Valerio Bocci

3. 21 Crystals Calorimeter Module (40 (phi) x (4+4) (theta) = 320 modules)
Cooling pipe
21 Preamp Boards inside this two
windows
2nd SuperB Collaboration INFN-LNF Dec 2011 Valerio Bocci

4. Crystals Moudule
2nd SuperB Collaboration INFN-LNF Dec 2011 Valerio Bocci

5. Preamplifier Asssembly
Epoxy Glue
2nd SuperB Collaboration INFN-LNF Dec 2011 Valerio Bocci

6. Way to replace Preamps Remove Extenal Remove the coling Access and
shiel
Remove the coling
pipes
Access and
Replace
Preamp

7. EMC Barrel readout granularity
X 2 Side (Fwd,Bck)
FWD
Mini
Crate 7 7 7 3 3 8 8 8 3
BWD
Mini
Crate
One phi row of 3(phi) x 24 (theta) Crystals is read out from same module
Physical Module = 3 * 7 =21 Crystals and 3*6 =18 last bkw
Trigger Tower =3*8=24 Crystals in Babar proposed 3*4=12 in SuperB
One optical fiber for two trigger module (3 optical fiber)
2nd SuperB Collaboration INFN-LNF Dec 2011 Valerio Bocci

8. Mini Crate structure Optica Fiber
Custom
Backplane
Preamp connection
Optica
Fiber
Digitizer
Board
Connection
Boards
2nd SuperB Collaboration INFN-LNF Dec 2011 Valerio Bocci

9. Connection Board 12 input cables from preamps
Distribution of PINs Power supply
Connected to Backplane board
2nd SuperB Collaboration INFN-LNF Dec 2011 Valerio Bocci

10. Mini Crate Backplane 6 Slots robust connection
2nd SuperB Collaboration INFN-LNF Dec 2011 Valerio Bocci

11. EMC Barrel Trigger Primitives (As before)
EMC Barrel :5760 CsI(Tl) Crystals
480 Sums unit
Warning: The 3 phi Crystal constraint request
A Chamber design with multiple
of (360/40*3)=3 deg granularity
at external layer
Sum of the energy deposition of
12 crystals of the barrel module
any sample time
2nd SuperB Collaboration INFN-LNF Dec 2011 Valerio Bocci 11 11

12. Crystals Test Box
2nd SuperB Collaboration INFN-LNF Dec 2011 Valerio Bocci

13. Crystals Test Box
2nd SuperB Collaboration INFN-LNF Dec 2011 Valerio Bocci

14. Setup
2nd SuperB Collaboration INFN-LNF Dec 2011 Valerio Bocci

15. Time jitter of the APD signals from CsI(Tl) crystal
Signal from external scintillator (PM readout)
Signal from CsI(Tl) (PM readout)
Signal froma CsI(Tl) (APD readout)
DSP d(apd)/dt to found the maximum
Jitter measurements 48 ns RMS
2nd SuperB Collaboration INFN-LNF Dec 2011 Valerio Bocci

16. INFN SuperB
Test of modification of the integration constant of the original Babar preamp to reduce pile up in SuperB (Measuraments from Luigi Recchia ) Rf=200M Cf=1pF -> Rf=2M Cf=1pF
(Measuraments from Luigi Recchia)
Cosmic signal Rf=200M (Original )
Cosmic signals Rf=2M

17. Preliminary test results of the Babar integrator time
constant modification to work with higher rate and backgrond
of SupeB. (Measuraments from Luigi Recchia )
ORIGINAL FRONT-END:
Pulse positive width 6us
undershot about 20 us
Total pulse width 25us -> RATE MAX= 40KHz?!
Modificated FRONT-END:
Pulse positive width 2.2us
undershot about 4 us
Total pulse width 6.5us -> RATE MAX= 150KHz

18. TDR EMC BARREL: Babar Mechanical constraint for electronics
Electronics changes
Rationale for changes
Premp design
Shaping and digitization
concentration and data transmission
Cabling
Forward:
Readout and Electronics
APD Readout
Electronics Block diagram
Preamplifier
Shaper
Digitization
Requirements on mechanics

19. Conclusions
The Mechanical structure of the Barrel give some strong physical
constraint to electronics design
It is impossible without risking to destroy the assembly to substitute the PIN diodes.
The form factor of the new preamplifier must be the same of the old one
The substitution of the Preamplifier it is not trivial but feasible (order 1 yr man pwr)
The Phi granularity for the readout and for the trigger is fixed
(3 cystals =>9 deg) it is preferable that the Chamber follow this granularity.
New Preamp,New (Digitizer + trigger sum),New Data Transmission
Test working in progress differents crystals differents preamp configuration
2nd SuperB Collaboration INFN-LNF Dec 2011 Valerio Bocci