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1 A CLUster COUnting Drift Chamber for ILC F.Grancagnolo, INFN – Lecce

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2 outline Requirements for tracking at ILC Cluster Counting 4 th Concept CLUCOU Drift Chamber 4 th Concept MUon Detector F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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4 From ILC, for B = 5 T, L = 1.5 m N = 150, L ~ 2m (1 cm 2 hex. cells) sense wires field wires F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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5 Multiple scattering contribution (equivalent L/X 0 ) : m W sense wires 1.8 × (X 0 = 0.35 cm) m Al field wires 2.2 × (X 0 = 8.9 cm) 2 m gas (90% He + 10% iC 4 H 10 ) 1.5 × (X 0 = 1300 m) Equivalent L/X 0 = 5.5 × Sagitta measurement contribution (in plane) : F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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6 4 th Concept TPC (160 pads) 4thConcept TPC + 5 pixel planes this CLUCOU Drift Chamber Momentum Resolution F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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7 CLUster COUnting 2 cm drift tube 90%He-10%iC 4 H 10 few x 10 gain 5 t : time separation between consecutive ionization clusters, as a function of their ordered arrival time, for different impact parameters. (caveat: electrons!) i+1,i In this He mixture, provided that: sampling frequency of signals > 2 Gsa/s and rise (and fall) time of single electron signals < 1ns single electron counting is possible. F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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8 CLUster COUnting MC generated events: 2cm diam. drift tube gain = few x 10 gas: 90%He–10%iC 4 H 10 no electronics simulated vertical arbitrary units cosmic rays triggered by scintillator telescope and readout by: 8 bit, 4 GHz, 2.5 Gsa/s digital sampling scope through a 1.8 GHz, x10 preamplifier b=0b=1 cm 10 mV 500 ns trigger signal t0t0 t last t first t max =1.6 s F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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9 CLUster COUnting For a given set up, and a digitized pulse (t last is constant with a spread < 20 ns) t 0 = t last – t max gives the trigger time b f = v(t) dt first approx. of impact parameter b (c/2) 2 = r 2 - b f 2 length of chord N cl = c / ( ( ) × sin ) expected number of cluster N ele = 1.6 x N cl expected number of electrons (to be compared with counted one) {t i } and {A i }, i=1,N ele ordered sequence of ele.drift times and their amplitudes P(i,j), i=1,N ele, j=1,N cl probability i-th ele. to j-th cl. D i (x) = (1-x) x probability density function of ionization along track t first t 0 N cl ! (N cl -i)! (i-1)! N cl -ii-1N cl F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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10 Each cluster contributes to the measurement of the impact parameter with an independent estimate weighted according to the Poisson nature of the process and the electron diffusion along the drift path. The resolution on the impact parameter, b, improves with the addition of each cluster beyond the first one. It, however, saturates at a value of m, convolution of: spread in mechanical tolerances (position of sense wire; gravitational sag; electrostatic displacement) timing uncertainties (trigger timing; electronics calibration; t 0 ) degree of knowledge of time-to-distance relation instability of working parameters (HV, gas temperature and pressure, gas mixture composition) Fit to resolution function: (from KLOE data) = m n p = 12.9 cm -1 D = 140 m cm -1/2 t = ns b b Reasonable to assume b = 50 m per sense wire F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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11 Particle Identification gas mixture = 95%He+5%iC 4 H 10 N cl = 10/cm beam test measurements p = 200 MeV/c experiment : theory: trunc. mean: CLUCOU chamber expected dN cl /dx resolution for a 2 m m.i.p. at 13 cluster/cm: (dN cl /dx)/(dN cl /dx) = 2.0 % F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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12 4thConcept ILC Drift Chamber Layout and assembly technique Length: 3.4 m at r = 22.5 cm 3.0 m at r = cm Spherical end plates: C-f. 12 mm + 30 m Cu (0.047 X 0 ) Inner cylindrical wall: C-f. 0.2 mm + 30 m Al (0.001 X 0 ) Outer cylindrical wall: C-f./hex.cell. sandwich held by 6 unidir. struts X 0 ) Retaining ring Stiffening ring Gas = X 0 Wires = X 0 TOTAL = X 0 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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13 4thConcept ILC Drift Chamber Layout Hexagonal cells f.w./s.w.=2:1 cell height: cm cell width: mm (max. drift time < 300 ns !) 20 superlayers, in 200 rings 10 cells each (7.5 in average) at alternating stereo angles ±72 ±180 mrad (constant stereo drop = 2 cm) sense w. 20 m W field w. 80 m Al easy t-to-d r(t) (few param.) >90% sampled volume F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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14 Summary for ILC A drift chamber à la KLOE with cluster counting ( 1GHz, 2Gsa/s, 8bit) uniform sampling throughout >90% of the active volume hexagonal drift cells in 20 stereo superlayers (72 to 180 mrad) cell width 0.6 ÷ 0.7 cm (max drift time < 300 ns) sense wires (20 m W), field wires (80 m Al) high efficiency for kinks and vees spatial resolution on impact parameter b = 50 m ( z = 300 m) particle identification (dN cl /dx)/(dN cl /dx) = 2.0% transverse momentum resolution p /p = 2·10 -5 p 5·10 -4 gas contribution to m.s. 0.15% X 0, wires contribution 0.40% X 0 high transparency (barrel 2.8% X 0, end plates 5.4%/cos X 0 +electronics) easy to construct and very low cost is realistic, provided: cluster counting techique is at reach (front end VLSI chip) fast and efficient counting of single electrons to form clusters is possible 50 m spatial resolution has been demonstrated F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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15 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC --- Drift Chamber for CMD-3 VEPP-2000, Novosibirsk G.V. Fedotovich and the CMD-3 Collaboration

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16 to be presented at F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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17 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC --- CLUCOU Proposal during

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18 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC --- rendering of first two superlayer stereo

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19 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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20 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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21 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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22 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC --- highest multiplicity events: 300 tracks per such event fraction of hit cells per ring superlayer average number of tracks crossing a hit cell 300 cells 680 cells

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23 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC m 7.7 m 12.8 m x 15.4 m diameter x length 4 th Concept layout

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24 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC BARREL CLUCOU chamber MUD barrel MUD E C N A D P 4 th Concept Dual Solenoid

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25 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC --- radius 2.3 cm filled with 90% He – 10% iC 4 H NTP gas gain few × 10 5 total drift time 2 µs primary ionization 13 cluster/cm 20 electrons/cm total both ends instrumented with: > 1.5 GHz bandwith 8 bit fADC > 2 Gsa/s sampling rate free running memory for a fully efficient timing of primary ionization: cluster counting accurate measurement of longitudinal position with charge division particle identification with dN cl /dx - system basic element: drift tube

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26 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC --- Drift tube end plug detail

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27 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC --- × 18 × 36 × tubes 26 cards 550 tubes 22 cards 1750 tubes 70 cards Modularity

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28 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC --- ×3× tubes 420 cards 1/3 of barrel

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29 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC tubes 1632 channels 76 cards ×6×6 1/3 end cap

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30 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC --- ×2×2 One end cap

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31 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC --- Barrel: tubes channels 840 cards End caps: 8640 tubes 9792 channels 456 cards Total: tubes channels 1296 cards Full muon system

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32 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC at 3.5 GeV/c

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33 Downscaling to SuperB F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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34 SuperB Drift Chamber Layout and assembly technique Length × Diameter : ~ 2.8 m × 0.8 m Spherical end plates: C-f. 6 mm equivalent + 30 m Cu (0.024 X 0 ) Inner cylindrical wall: C-f. 0.2 mm + 30 m Al (0.001 X 0 ) Outer cylindrical wall: C-f./hex.cell. sandwich held by 6 unidir. struts X 0 ) Retaining ring Stiffening ring Gas = X 0 (80%He+20%iC 4 H 10 ) Wires = X 0 TOTAL = X 0 F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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35 SuperB Drift Chamber Layout Hexagonal cells f.w./s.w.=2:1 cell height: ~ 1.70 cm cell width: ~ 10. mm (max. drift time < 700 ns !) 10 superlayers in 100 rings 10 cells each (7.5 in average) at alternating stereo angles ±72 ±130 mrad (constant stereo drop = 2 cm) sense w. 20 m W field w. 80 m Al easy t-to-d r(t) (few param.) >90% sampled volume F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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36 Summary for SuperB A drift chamber à la KLOE with cluster counting ( 1GHz, 2Gsa/s, 8bit) uniform sampling throughout >90% of the active volume hexagonal drift cells in 8 stereo superlayers (72 to 130 mrad) cell width ~ 1.0 cm (max drift time < 700 ns) sense wires (20 m W), field wires (80 m Al) high efficiency for kinks and vees spatial resolution on impact parameter b = 50 m ( z = 400 m) particle identification (dN cl /dx)/(dN cl /dx) = 2.3% transverse momentum resolution p /p = 1.0·10 -3 p 1.5·10 -3 gas contribution to m.s. 0.14% X 0, wires contribution 0.03% X 0 high transparency (barrel 2.2% X 0, end plates 2.6%/cos X 0 +electronics) easy to construct and very low cost is realistic, provided: cluster counting techique is at reach (front end VLSI chip) fast and efficient counting of single electrons to form clusters is possible 50 m spatial resolution has been demonstrated F. Grancagnolo. INFN – Lecce --- CLUCOU for ILC ---

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