1. A cluster counting drift chamber for central tracking at ILC Roberto Perrino INFN Lecce INSTR08 Novosibirsk Mar 1, 2008

2. Outline Tracking requirements at the ILC Low density DCH + Cluster counting Expectations for the CluCou DCH (ILC 4 th Concept) CluCouCluCou R&D Program Status of the Experimental Tools Summary and outlook INSTR08 Novosibirsk

3. A golden channel for SM Higgs:  Z decay is tagged by clean l + l _ decays H-mass measured independent of decay channel, because of constrained kinematics LHC machine for discovery machine for precision measurements [ ILC-Reference Design Report - Vol.I ] Which precision? Unbiased benchmark case:Higgs detection at the ILC

4. How to meet P T resolution requirements? ILC-type TPC + 5 layers of Si pixels KLOE-type DCH  m New DCH with potential  m [G. Tassielli, Doctoral Dissertation, Feb 2008] We can operate on both arms of Light-mass DCH He+wires Higher position resolution track sampling 0.5 % X 0 Greatly Improves p T <25 GeV/c  m Greatly Improves p T >25 GeV/c

5. [C. Grupen - Particle Detectors - Cambridge U. Press] He-based mixture Low drift velocity (  2.5 times less than Ar) Low ionization density along track (  5 times less than Ar) Read-out elx Risetime  ns Sampling rate  Gsa/s 0.4 ns/chan mip crossing 2 cm radius drift tube He+iC 4 H 10 (90/10) With lesson learned from e.g. KLOE and BaBar

6. A cluster counting central DCH for future experiments at ILC (4 th Concept proposal) Design and construction of such type of chamber relying on robust engineering calculations and consolidated carbon fiber technology (e.g. KLOE, Novosibirsk DCH) KLOE-like DCH  CluCou (≥1GHz; ≥2 GSa/s; 8 bit)  1.5 m track-length; ~125 points/track;  = 60  m  He-based mix ⇒ contribution to m.s.~0.15% X 0  60K Hex 0.6-0.7 cm cells in 20 s_layers  Full stereo U-V ±72-180mrad  60K 20  m sense wires; 120K 80  m Ewires  Uniform sampling over >90% of volume  Position resolutions:  b  = 60  m ;  z  = 300  m  PID resolution ~2% through dN cl /dx

7. Expectations for CluCou DCH @ ILC 4th Concept Simulation in the ILCRoot framework: √s=230 GeV @ 500 fb -1 [G. Tassielli, Doctoral Dissertation, Feb 2008] e + e - → HZ → X + µ + µ -

8. The CluCou R&D Program Software simulations (Garfield, Magboltz): control of the gas transport parameters electrical characterization of drift cell measurability of single electron FE elx transfer function Simple cosmic ray experimental setup (drift tubes, trigger, fast digital scope) Development of fast FE VLSI ASIC (preamp, shaper, ADC, buffer) Precision  strip tracker for detailed study DCH small scale prototype construction CR-test and beam-test of DCH prototype Waveform analysis and cluster counting algorithms

9. CLUCOU Simulation: Gas parameters He-iC 4 H 10 90%-10%85%-15%80%-20% n cl /cm11.315.319.6 n el /n cl 1.601.62 Based on packages: HEED, MAGBOLTZ, GARFIELD9 and ROOT Number of clusters/cm and e - /cluster Clusters Poisson ionization statistics He-iC 4 H 10 Working Point Electron Landau ionization statistics [G. Chiodini - SuperB Detector R&D - Slac Feb 2008]

10. CLUCOU simulations: Peak Finder after Front-End Atlas internal note MUON-NO-105 (1995) and PS-SPICE Gain Phase ~1MHz ~3GHz [G. Tassielli, Doctoral Dissertation, Feb 2008] FE response

11. CluCou Measurements Scintillator trigger Drift tube: r = 1.4 cm L=30 cm He 90% + iC 4 H 10 10% Sense wire 25  m ∅ HV  V 10 × Preamp @ bw=500 MHz 2.5 Gsa/s 4GHz bw digital scope Slow control parameters continuosly monitored (HV, Temp, Press, GasFlow) t dr tt t FIRST t LAST

12. “Confidence gaining” results R=1.2 cm R=2.0 cm  t=900 ns High # of peaks Short arrival time Little Impact Parameter DriftTime “white” spectrum Look forward to select impact parameter with micrometric tracker

13. A precision tracking telescope

14. CLUCOU measurements: Si-Telescope (I) Linux OS FNAL PTA card FNAL Mezzanine PCI bus XILINX FPGA ALTERA FPGA ILLINOIS adapter board Daisy-Chain 6 CDF Run2b modules Module~4x18 cm 2 = 1 hybrid+ 2 Si sensor: 8 bit ADC p+/n sensors 75um readout pitch with intermediate floating strips HV caen LV Power Supply TTL Trigger In Hardware ready Firmware ready Software to finalize for: tracking analysis Two Si-modules already readout in daisy chain External trigger readout 6 modules + 4 spare available Mechanical assembly and HV ready. Drift tube Under test Many thanks Fermilab ESE department and Thomas Junk (IL Urbana University) !!! [G. Chiodini - SuperB Detector R&D - Slac Feb 2008]

15. Si - telescope and Device Under Test. Only one Si plane shown out of 6. 6 plane microStrip-Si telescope Next: Tracking on cosmics - X 0 Material not optimized yet CLUCOU measurements: Si-Telescope (II) Full adjustable angles 1.2 0 step Easy to upgrade to more planes [G. Chiodini - SuperB Detector R&D - Slac Feb 2008]

16. The CluCou Chip Technology = 0.13 µm CMOS Core area = 2.4 mm 2 ADC: Resolution = 6 bits Sample rate = 1 GSa/s FS input range = 160 mV Preamp: Programmable DC-gain 0-20 dB BW 500 MHz @ -3 dB Input-referred noise = 52  V rms wrt drift tube output noise of 100  V rms [S. D’Amico - Proc. IWASI2007 - Bari June 26-27, 2007] Design specs

17. CluCou FE Chip test plan Last Word from TESTS ON DETECTOR’s FE BENCH TESTS: Polarization: control of absorbed current and output voltages Characterization of variable gain amplifier prior to ADC Frequency response for different gains Noise and linearity Characterization of the ADC S/N ratio evaluation + distorsion Feb 18th 2008: 70 chips delivered Feb 22nd 2008: Test boards delivered In the course of setting-up bench tests (electrical, general functionality)

18. Summary & Outlook  The CluCou Collaboration is exploring the introduction of a very light He-based DCH with cluster counting capabilities  Exploration of new light materials for wiring (carbon, polyester, as thin as 10  m)  Solution applicable to ILC for pushing to extreme resolution on momentum measurements (or to SuperB Factories for PID with ionization density measurement)  MC computational tools developed for exploring the improvement of single point position resolution to 50  m  VLSI ASIC designed for 1 GHz bw and 1 Gsa/s 6 bit waveform sampling; first 70 out of foundry ready for testing  Experimental tools for consistency check of simulations with drift tubes and cosmic rays INSTR08 Novosibirsk In progress this year:  Bench tests of the 70 pre-production CluCou chips; get conclusions within 2008  Further development of peak-counting algorithms for efficient waveform analysis  Setting-up microstrip telescope for detailed study of the ionization statistics, r-t relation and resolution  Event-by-event measurements on drift tubes with the CluCou chip and a commercial board (National Semiconductors) for performance comparison On the longer run (2009)  Design and build a prototype DCH w/ 50 cells fully equipped with FE elx  Test of the prototype DCH with cosmics  Test of the prototype DCH in a testbeam

19. Credits The CluCou Collaboration F. Grancagnolo [1], A. Baschirotto [2,1], G. Chiodini [1], P. Creti [1], S. D’Amico [2,1], M. De Matteis [2,1], M. Panareo [2,1], R. Perrino [1], S. Spagnolo [3,1], G.F. Tassielli [3,1] 1) INFN Lecce 2) Università del Salento, Dipartimento di Ingegneria dell’Innovazione, Lecce 3) Università del Salento, Dipartimento di Fisica, Lecce INSTR08 Novosibirsk