Straw spatial resolution (beam test 2007 and 2008) A.Zinchenko, S.Shkarovskiy

Muon and pion runs(2007), Muon runs (2008) Gas mixture(2007) – CO2+isoC4H10+CF4 (80:10:10) Gas mixture(2008) – CO2+isoC4H10+CF4 (82:5:13) Front end chip – ASD-8 (2007) ASDQ, CARIOCA (2008) Threshold: 6 fC HV: (2200 –2700) V (Gas gain: – 10 6 )

Comparison ASD-8, ASDQ and CARIOCA Front-End Chips

Straw resolution vs R (ASD-8) Ua=+2400 V Gas Gain G=110 5 Straw resolution (sigma) 40x1.2=48 mkm R (cm) Th= 6 fC Th=12 fC Sigma of residuals (cm) Muon runs Straw resolution (sigma) 45 mkm Straw resolution (cm) vs R (cm) (Garfield) Th= 6 fC Th=12 fC

Straw residuals vs HV (ASD-8, beam test 2007) Muon+pion runs Th=6 fC for straw R>3 mm

Straw residuals vs HV ( ASDQ, CARIOCA ) Beam test 2008, ASDQ Beam test 2008, CARIOCA R = 350 Ohm R = ∞ Ohm R = 350 Ohm R = ∞ Ohm Residual, mkm HV, V Threshold Th= 6 fC, for straw R=3 mm HV, V Straw resolution 40x1.2 = 48 mkm Straw resolution 60x1.2 = 72 mkm

Straw residuals vs HV ( ASDQ, CARIOCA ) Beam test 2008, ASDQ Beam test 2008, CARIOCA R = 350 Ohm R = ∞ Ohm R = 350 Ohm R = ∞ Ohm Residual, mkm HV, V Threshold Th= 6 fC, for straw R=3 mm HV, V Straw resolution 40x1.2 = 48 mkm Straw resolution 50x1.2 = 60 mkm

R, cm Beam test 2008, ASDQ Beam test 2008, CARIOCA Beam test 2007, ASD-8 GARFIELD, ASDQ GARFIELD, CARIOCA GARFIELD, ASD-8 Ua=2600 V Ua=2500 V Ua=2400 V Ua=2600 V Ua=2500 V Ua=2600 V Ua=2500 V Ua=2600 V Ua=2500 V Residuals, mkm Straw resolution vs R ( ASD-8, ASDQ, CARIOCA )

Straw resolution vs R Threshold Th=6 fC ASD-8 HV=2400 V G= ASDQ HV=2500 V G= CARIOCA HV=2600 V G= Resolution, cm R, cm NA62 requerement ASD-8 HV=2400 V G= ASDQ HV=2500 V G= CARIOCA HV=2600 V G= Residual, cm R, cm NA62 requerement Beam test 2007, 2008GARFIELD

Amplification vs Wire Voltage GARFIELD Amplification Voltage, V 2375 V2490 V CO2+isoC4H10+CF4 (80:10:10)CO2+isoC4H10+CF4 (82:5:13) dU shift = 115 V

Comparison CARIOCA Front-End Chips with transistor and resistor termination

CARIOCA cold (2 boards) ch1 ch8 ch1 ch8 ch1 ch8 ch1 ch8 ch1 CARIOCA hot (2 boards) ASDQ (2 boards) Particles Straw far-end Open Hot Open Hot Open Hot Straw near-end Inputs TDC1 (32 channels) TDC2 (32 channels) # - dead wires # - tubes used for reconstruction CARIOCA cold =transistor termination CARIOCA hot = resistor termination

Time spectrum from tube with CARIOCA hot Time spectrum from tube with CARIOCA cold RT-dependence Drift time, ns R,cm

Row with CARIOCA resistor termination Sigma residuals = 33.6 μm Row with CARIOCA transistor termination Sigma residuals = 47.2 μm Residuals, cm Straw residuals ( CARIOCA )

Straw Efficiency vs Radius (ASD-8, th=6 fC) Ua=+2400 V (G=110 5 ) R effective =4.7 mm Data muon runs R effective =4.8 mm Efficiency vs R (cm) (Garfield)

Results ASD-8 resolution (2007): The minimal limit of straw spatial resolution is about 48 µm for gas gain higher than G=110 5 and compare with Garfield simulation result (45 µm) Efficiency (2007): 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)

Results Resolution (2008): The minimal limit on straw spatial resolution for ASDQ (R = ∞) and for CARIOCA (R = ∞) is about 50 µm and compare with Garfield simulation result CARIOCA with resistor termination is better than CARIOCA with transistor termination Slightly wrong definition of RT-dependence and Т0 leads to insignificant degradation of the straw spatial resolution (compare results on slide 6 and 7)

Conclusions Comparison ASD-8, ASDQ and CARIOCA FEE: Straw spatial resolution for ASD-8, ASDQ and CARIOCA is about the same. The minimal limit of straw spatial resolution is about 50 µm For gas mixture CO2+isoC4H10+CF4 (82:5:13) HV working point is in the range (2500 – 2600) V -> G=(1-2) 10 5 Comparison CARIOCA termination schemes: CARIOCA with resistor termination is better than CARIOCA with transistor termination ASD channels is available at Dubna