Read-out set-up and test results P. Salabura on behalf of Kraków crew

Read-out scheme Prototype I (july 2011) in tests TRB v2 128 channels HPTDC Evaluation board

ASIC interface ASIC setting for in-beam and radioactive source tests in 2012/2013 selected: rising time ~40 ns,pulse duration ~ 150 ns stable operation with tubes (no oscilations) Installed in Kraków, Juelich Installed also at GSI with HADES MDC- comparison to AD8 – on going Fe signal

Examples of signal: Fe-source Preamp- saturation Typical signal Asic setting: reduce Pramp gain (1.) to eliminate preamp-saturation

Event Display (new-since 2 weeks)

Plateau measurements ‘ 2013 Kraków straws January 2013

TOT vs charge characteristics: Fe source Q/Q~11% Q/Q~9% Total charge ~ few percent resolution below 1875 V: for higher HV resolution degradation due to Preamp saturation TOT vs charge dependence : typical shape for quasi-Gaussian pulses

TOT vs Tdrift -0.9 GeV protons September’ 2012 Juelich Simulation: Garfield + FEE transfer 1 GeV/c miuons 130 ns TOT [ns] Tdrift [ns] as expected besides second leg structure in TDrift>130 ns !!! ? pile-up due to micro bunch structure of the beam? – I doubt it – see next slides secondary emission from tube walls? electronic effects : cross talk (we could not find evidence for that)

TOT vs Tdrift vs HV (900 MeV/c protons) 1700 V 1750 V 1800 V T~130 ns time direction reversed separation between 2 structures increases with HV

Sr90 vs in- beam measurement same set-ups : 2 rows of straws aligned w.r.t beam Trigger : and between 2 scint. (in Krakow we use similar straws)

Spectra from one straw Juelich: p 900 MeV HV=1800 V Kraków: Sr90 HV=1800 V Tot [ns] Tdrift [ns] Tdrift [ns] several (>8) straws fired At least 5 straws fired + 2 scintil. similar second leg structure visible in sr90 case Sr90: can not be due to pile-up

Spectra from one straw when 2’d fired Juelich: p 900 MeV second straw in the same row Kraków: sr90 second straw in the same row second straw in the row below second straw in the row below

Correlation plots Juelich: p 900 MeV second straw in the row below Tdrift j+1 Kraków: Sr90 second straw in the row below Tdrift j j j+2 j+1

Further source tests are needed to understand origing of delayed signals in straw (Gas, mixtures, HV dependence, ASIC settings?) will be continued in Kraków Test at GSI with MDC . FEE + TRB installed . ASIC adopted to MDC signals (faster rising and larger gain) TOT / Charge / position resolution from in-beam data– see Jacek talk