29-Feb-16S.Movchan Straw status1 Choose of FEE chip for NA62 straw detector Beam tests results 2007 and 2008 (Straw spatial resolution) Comparison FEE based on chips: ASD-8 CARIOCA ASDQ Garfield results (gas gain, resolution,…) Threshold value estimation Conclusion Presented by S.Movchan

29-Feb-16S.Movchan Straw status2 ASD-8 Gas mixture – CO2+isoC4H10+CF4 (80:10:10) Front end chip ASD-8: K=5 mv/fC, noise (Cd=20pF) N= 2000 e-, Rin=110 Ohm Threshold sets: 6 fC and 12 fC HV sets: (2200 –2700) V (Gas gain: 2x10**4 – 10**6) Pion runs: Th: 6 fC HV: 2200, 2300, 2400 Volts Muon runs: Th: 6 fC and 12 fC HV: 2400, 2500, 2600 Volts

29-Feb-16S.Movchan Straw status3 Residual vs R, pions

29-Feb-16S.Movchan Straw status4 Residual vs R, muons

29-Feb-16S.Movchan Straw status5 Straw residual vs HV Muon+pion runs Th=6 fC for straw R=3 mm

29-Feb-16S.Movchan Straw status6 Straw resolution vs R (ASD-8, th=6-12 fC) Ua=+2400 V (G=2x10**5) Straw resolution (sigma) 35x1.2=40 mkm R (cm) Th= 6 fC Th=12 fC Sigma of residuals (cm) Muon runs Straw resolution (sigma) 35 mkm Straw resolution (cm) vs R (cm) (Garfield)

29-Feb-16S.Movchan Straw status7 Straw efficiency vs R (ASD-8, th=6 fC) Ua=+2400 V (G=2x10**5) R effective =4.7 mm Muon runs R effective =4.8 mm Efficiency vs R (cm) (Garfield)

29-Feb-16S.Movchan Straw status8 Straw spatial resolution and efficiency For ASD-8 chip: K=5 mv/fC, noise (Cd=20pF) N= 2000 e-, Rin=110 Ohm Resolution: Straw spatial resolution limit is about 40 µm for R=(3-5) mm for gas gain higher than G=2x10**5 and compare with Garfield simulation result (35 µm) Efficiency: Straw efficiency is about 100% for R effective up to 4.7 mm and compare with Garfield simulation result (R up to 4.8 mm)

29-Feb-16S.Movchan Straw status9 CARIOCA and ASDQ Gas mixture – CO2+isoC4H10+CF4 (82:5:13) ppm O ppm N2 CARIOCA: K=15 mv/fC, noise (Cd=20pF) N= 3000 e-, Rin=10 Ohm Straw termination: R term.=350 Ohm ASDQ: K=12 mv/fC, noise (Cd=20pF) N= 2000 e-, Rin=120 Ohm Straw termination: R term.=230 Ohm Threshold sets: 4-6 fC and 15 fC HV sets: 2400 –2700 V (Gas gain:5x10**4 – 5x10**5) Muon runs: Th: 4-6 fC and 15 fC HV: 2400, 2500, 2600, 2700 Volts

29-Feb-16S.Movchan Straw status10 Residual vs R: comparison FEE electronics Th=“6 fC” ASD-8ASDQ/CARIOCA 2500V The same dependence Th=6 fC

29-Feb-16S.Movchan Straw status11 Garfield simulation results: gas gain vs HV for unflammable gas mixture CO2/isoC4H10/CF4 (82:5:13) “effective” threshold value estimation for different front end chips straw resolution versus radius for different thresholds

29-Feb-16S.Movchan Straw status12 Gas gain vs HV HV shift: dUa=115 V

29-Feb-16S.Movchan Straw status13 Gas gain vs HV, linear scale HV=2400 V for ASD-8 is compatible with HV =2515 V for CARIOCA/ASDQ

29-Feb-16S.Movchan Straw status14 Measurements: ASD-8 (Beam test 2007) eff=50% at Ua=2150 V

29-Feb-16S.Movchan Straw status15 Garfield: ASD-8 eff=50%: Th= 6 fC -> 2075 V Th=10 fC -> 2150 V Th=15 fC -> 2200 V Th=25 fC -> 2270 V

29-Feb-16S.Movchan Straw status16 Measurements: CARIOCA and ASDQ (Beam test 2008) eff=50% at Ua=2275 V

29-Feb-16S.Movchan Straw status17 Garfield: CARIOCA eff=50%: Th= 6 fC -> 2025 V Th=15 fC -> 2160 V Th=25 fC -> 2225 V Th=30 fC -> 2250 V

29-Feb-16S.Movchan Straw status18 Threshold value estimation for different front end chips from measurements of straw counting plato: ASD-8 -> Th= 10 fC CARIOCA/ASDQ -> Th= 30 fC From calibration: ASD-8 (S.Vasiliev) -> Th= 6 fC CARIOCA/ASDQ -> Th= (4-6) fC (A.Kaschuk) x 3 times 1 ?

29-Feb-16S.Movchan Straw status19 Straw resolution vs R Physical limitwith ASD-8 R (cm) Sigma (mkm) Sigma (mkm) 2 mm1 mm Resolution vs R near anode wire strongly depends from gas gain and threshold (preamp.) Near the straw wall a physical limit of resolution is achieved without problem

29-Feb-16S.Movchan Straw status20 Straw resolution vs R for different thresholds (ASD-8) G=2x10 4 Th=6.0 fC Th=3.0 fC Th=0.5 fC Physical limit Resolution vs R near anode wire strongly depends from gas gain and threshold Near the straw wall a physical limit of resolution is achieved without problem (ASD-8 preamp.)

Simulation conditions Ø Tube 9.75 mm Ø Wire 30 μm FEE CARIOCA HV 2400 V Gas Gain 4∙10 4 Threshold 4 fC Pressure – bar Temperature 290 K – 310 K

Drift time, μs CO 2 80% CF 4 10% C 4 H 10 10% CO 2 80% CF 4 13% C 4 H 10 7% CO 2 80% CF 4 14% C 4 H 10 6% CO 2 82% CF 4 13% C 4 H 10 5% CO 2 90% CF 4 5% C 4 H 10 5%

Drift time, μs p = 1 bar p = bar p = bar t = 300 K t = 310 K t = 290 K p = 1 atm p = atm p = atm t = 300 K t = 310 K t = 290 K No msc, δ-e -, amplifier With msc, δ-e -, amplifier No msc, δ-e -, amplifier With msc, δ-e -, amplifier

Resolution, μ m p = 1 bar p = bar p = bar No msc, δ-e -, amplifier No msc, δ-e -, amplifier Spatial resolution by pressure & temperature Radius, cm Mean of gauss, μ m t = 300 K t = 310 K t = 290 K No msc, δ-e -, amplifier Resolution, μ m Mean of gauss, μ m No msc, δ-e -, amplifier

29-Feb-16S.Movchan Straw status25 Conclusion Unflammable gas mixture CO2/isoC4H10/CF4 (82:5:13) can be used Straw resolution versus R is reachable by each chip: 200 μm near anode wire and μm for R=(3-5) mm Min “effective” threshold for ASD-8 chip is Th=10 fC while for CARIOCA and ASDQ chips min “effective” threshold is Th=30 fC. Due to this ASD-8 chip can operate at HV=2400 V instead HV= V for CARIOCA and ASDQ Straw efficiency is about 100 % for radii up to R=4.7mm Each chip ASD-8, CARIOCA and ASDQ can be used for NA62 straw tracker Available amount of FEE: ASD-8: spare=500 boards/16ch each, in total 8000 ch (Dubna) CARIOCA:available as wafers only, 8000 ch (LHCb) ASDQ:1000 chips/8ch each, in total 8000 ch (PANDA)