1. J-C Brient-DESY meeting -Jan/2004 1 The 2 detector options today …. SiD vs TDR [ * ] [ * ] J.Jaros at ALCPG-SLAC04 ECAL ECAL tungsten-silicon both optionsHCAL Digital (RPC,GEM,..) Digital / Tile AHCAL Digital (RPC,GEM,..) Digital / Tile AHCAL CALORIMETRY TRACKER Silicon trackerTPC for TDR Silicon tracker TPC for TDR Partly the same people SiD TDR

2. J-C Brient-DESY meeting -Jan/2004 2 ECAL HCAL The 2 options of J.Jaros Silicon cost TDR Silicon cost SiD ~ 2.6

3. J-C Brient-DESY meeting -Jan/2004 3 What is the reason for the TPC radius of 1.60m Single track resolution ? Separability ? What is the reason for 1.70m for the ECAL radius TPC radius + 10cm Charged track - photon separation Reducing the external radius of the TPC (reduce the cost of the overall detector) if needed a precise point outside TPC can be added ?? what about the separation charged-neutral ?? See next slides See later What is the reason for 2.50m for the TPC length Covering at low angle ? but the FTD is doing it with FCH Tracker size ECAL size Radius, length, size, …

4. J-C Brient-DESY meeting -Jan/2004 4 ∆Z≈ Strip Width ECAL module Add alveoli without tungsten ▪ Minimize the thickness/”tracker point” ▪ Minimize the distance to the ECAL ▪ Minimize the inter alignment tracker-ECAL Example for the TPC T0 Strips along RΦ in the barrel Of course It could be a pixels device or a double side det. with strips … if the cooling for the VFE is not needed or if it fits inside the alveoli … Reducing the external radius of the TPC ?? Need precise point(s) Just before the ECAL (large radius)

5. J-C Brient-DESY meeting -Jan/2004 5 PCB or Kapton Silicon Strips Matrix VFE + ADC+ MUX IN-OUT Possible scheme of a “tracker” alveoli The overall thickness fits inside the standard alveoli of the ECAL

6. J-C Brient-DESY meeting -Jan/2004 6 ECAL-SiD- ALCPGECAL-TDR- CALICE 1.27m 1.68m At least, there is a good agreement on the global geometry [ * ] Is it so different ? Geometry of the calorimeter [ * ] The calorimeter 8-fold way of Henri Videau

7. J-C Brient-DESY meeting -Jan/2004 7 e + e – → ZH → jets at √s = 500 GeV Presentation at LBL 2000 – LC meeting For SD geometry, there is an average of ~65GeV of photons closer than 2.5 cm versus ~20 GeV for the TDR geometry SD geometry TDR geometry The ECAL internal radius WARNING SD here use B=6T while now people talk of B=5T

8. J-C Brient-DESY meeting -Jan/2004 8 Energy per event for photons closer than 2.5 cm from a charged track At the ECAL entrance GeV Distance to closest CH. cm Fraction of the photons energy Example here with B=4T, R=170cm at 800 GeV e + e – → W W at √s = 800 GeV 14% of the sample The average is here What for different physics process

9. J-C Brient-DESY meeting -Jan/2004 9 Fraction of photons energy at D<Rm Internal radius fixed at 1.50 m and B=4T Distance of the ECAL endcap W W final state at 800 GeV We define Rm at 2cm When going to 1 TeV Variation with the ECAL endcap entrance SiD Value Length of the TPC Efficiency of reconstructing photons close to ch. track (D<Rm) is <<100%

10. J-C Brient-DESY meeting -Jan/2004 10 Fraction of photons energy at D<Rm Z endcap at 2.00 m and B=4T Internal radius of the ECAL 1 TeV W W final state at 1 TeV We define Rm at 2cm Variation with the internal ECAL radius SiD Value SiD ValuesRint=125, Zec=170 and B=5T

11. J-C Brient-DESY meeting -Jan/2004 11 30 layers 25 layers 20 layers Internal radius of the ECAL Length of the ECAL barrel TESLA TDR Curves ISOCOST(area) versus SiD SiD detector Possible Interesting Region

12. J-C Brient-DESY meeting -Jan/2004 12 (R=170cm and 4T) For the TDR type of detector (R=170cm and 4T) 14% 14% of the events have more than 50 GeV in the difficult region (R=125cm and 5T) For the SiD detector (R=125cm and 5T) 32% 32% of the events have more than 50GeV in the difficult region For the photon(s) reconstruction, the ECAL radius is much more important !!! Impact on the jets to be quantified Impact on the jets to be quantified To reduce the ECAL cost, Playing with the layers number is more efficient and less penalizing for the performances on jet, ,… ?! + the TPC length could also be reduced without a strong effect ? (my guess) VERY IMPORTANT NUMBERS The relevant law is in BR 2 /Rm Do we goNOWto15-20 layersECAL at R=1.40 -1.50m?? Do we go NOW to 15-20 layers ECAL at R=1.40 -1.50m ??

13. J-C Brient-DESY meeting -Jan/2004 13 Summary of the ECAL change vs TDR ► VFE inside for the ECAL, alveoli thinner, better eff. Molière radius ► For the simulation, I propose to use 30 layers to be consistent with the SiD ECAL Changing the general geometry ► VFE inside for the HCAL (Si-PM, or digital readout for DHCAL) → NO SPACE for fibbers in overlap !!! → NEW distance TPC-ECAL in endcap !!!! VFE (with ADC?) send each BX to DAQ board (with/without ADC)  DAQ-ADC board digitise, store in digital memory, MUX to optical link VFE inside DAQ-ADC board ▪ VFE time occupancy is about 1/200 for TESLA ▪ VFE On-Off take about 100  s  1/20 is a reasonable value of the duty cycle Passive cooling would be sufficient ECAL readout R&D in CALICE ECAL with MOU between IN2P3 and MOST to quantify this passive cooling limit

14. J-C Brient-DESY meeting -Jan/2004 14 ► FCH (SET?) in silicon device inserted in ECAL CFi frame ? ► ECAL as the track seed for SiD tracker ? a kind of substitute for the TPC number of points Other open questions ► Quantitative variation of performances on jet(s) TPC size (and impact on physics program) with TPC size ► What is the number of X0 of the endplate and readout electronics ? what is the distance TPC-ECAL ? ► Is there a way to avoid the hole between Forward CAL and ECAL together with the possibility to open the detector ? ► The CALOR. endcap geometry must be reviewed