EMC Barrel Electronics Status Valerio Bocci INFN Roma

EMC Barrel Electronics Status Valerio Bocci INFN Roma 2 nd Super. B Collaboration Meeting @ INFN-LNF 13 -16 Dec 2011 Valerio Bocci

ac Visit Nov 2011 Location of the Front End electronics in the EMC barrel Data Transmission Unit (ex IOB) 40 DTU 2 nd Super. B Collaboration Meeting @ INFN-LNF 13 -16 Dec 2011

21 Crystals Calorimeter Module (40 (phi) x (4+4) (theta) = 320 modules) Cooling pipe 21 Preamp Boards inside this two windows 2 nd Super. B Collaboration Meeting @ INFN-LNF 13 -16 Dec 2011 Valerio Bocci

Crystals Moudule 2 nd Super. B Collaboration Meeting @ INFN-LNF 13 -16 Dec 2011 Valerio Bocci

Preamplifier Asssembly Epoxy Glue 2 nd Super. B Collaboration Meeting @ INFN-LNF 13 -16 Dec 2011 Valerio Bocci

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

EMC Barrel readout granularity X 2 Side (Fwd, Bck) FWD Mini Crate 7 7 7 3 3 8 8 8 3 • 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 Super. B • One optical fiber for two trigger module (3 optical fiber) BWD Mini Crate 2 nd Super. B Collaboration Meeting @ INFN-LNF 13 -16 Dec 2011 Valerio Bocci

Mini Crate structure Custom Backplane Preamp connection Optica Fiber Digitizer Board Connection Boards 2 nd Super. B Collaboration Meeting @ INFN-LNF 13 -16 Dec 2011 Valerio Bocci

Connection Board • 12 input cables from preamps • Distribution of PINs Power supply • Connected to Backplane board 2 nd Super. B Collaboration Meeting @ INFN-LNF 13 -16 Dec 2011 Valerio Bocci

Mini Crate Backplane 6 Slots robust connection 2 nd Super. B Collaboration Meeting @ INFN-LNF 13 -16 Dec 2011 Valerio Bocci

EMC Barrel Trigger Primitives (As before) • EMC Barrel : 5760 Cs. I(Tl) Crystals • 480 Sums unit Sum of the energy deposition of 12 crystals of the barrel module any sample time Warning: The 3 phi Crystal constraint request A Chamber design with multiple of (360/40*3)=3 deg granularity at external layer 2 nd Super. B Collaboration Meeting @ INFN-LNF 13 -16 Dec 2011 Valerio Bocci

Crystals Test Box 2 nd Super. B Collaboration Meeting @ INFN-LNF 13 -16 Dec 2011 Valerio Bocci

Crystals Test Box 2 nd Super. B Collaboration Meeting @ INFN-LNF 13 -16 Dec 2011 Valerio Bocci

Setup 2 nd Super. B Collaboration Meeting @ INFN-LNF 13 -16 Dec 2011 Valerio Bocci

Time jitter of the APD signals from Cs. I(Tl) crystal 1) 2) 3) 4) 5) Signal from external scintillator (PM readout) Signal from Cs. I(Tl) (PM readout) Signal froma Cs. I(Tl) (APD readout) DSP d(apd)/dt to found the maximum Jitter measurements 48 ns RMS 2 nd Super. B Collaboration Meeting @ INFN-LNF 13 -16 Dec 2011 Valerio Bocci

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

Preliminary test results of the Babar integrator time constant modification to work with higher rate and backgrond of Supe. B. (Measuraments from Luigi Recchia ) ORIGINAL FRONT-END: • Pulse positive width 6 us • undershot about 20 us • Total pulse width 25 us -> RATE MAX= 40 KHz? ! Modificated FRONT-END: • Pulse positive width 2. 2 us • undershot about 4 us • Total pulse width 6. 5 us -> RATE MAX= 150 KHz

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 • concentration and data transmission • Requirements on mechanics

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 2 nd Super. B Collaboration Meeting @ INFN-LNF 13 -16 Dec 2011 Valerio Bocci