MuTr Chamber properties K.Shoji Kyoto Univ.

Measurement of MuTr raw signal Use oscilloscope & LabView Read 1 strip HV 1850V Gas mixture Ar:CO 2 :CF 4 =50%:30%:20% Total resistance 10kohm

Typical Pulse Shape

Fit to these region Ground Level Noise Subtract Event-by-event ground level noise subtract Use linear function y=gradient*x+intercept 3000 samples

Decay time Detector Capacitance C Total Resistance R=9800ohm ～ 10Kohm Exp(-t/CR) Fit Error <300nsec CR ～ 2.8usec ⇒ C ～ 300pF (?)

Pulse Height and Charge distribution Distribution of 1 Strip Typical Charge is 200fC But I used narrow scintillator for trigger, These distribution has dependence of place Pulse height charge Pulse HeightCharge

Correlation of Pulse Height & Charge There is clear correlation. But little bit rise where pulse height is low Because of the Noise?

Simple Model Cross mark is Profile of pulseheight&charge Red is Model Line

ASD Chip for MuTr LL1 Trigger 4 Channels for 1 Chip Input Impedance 370ohm Preamp Integration Time 80nsec Preamp gain 0.8mV/fC ENC 2000electrons for 300pF ⇒ Analog output Main amp gain 7 Comparator with LVDS output Threshold voltage : common for all 4 channels ⇒ Digital output

Expected Response of ASD Chip Input Impedance 370ohm Preamp Integration Time 80nsec Preamp gain 0.8mV/fC C ～ 300pF ⇒ CR ～ 110nsec Analog output Rise time : few ～ 10nsec

Linearity of ASD Chip 1Kohm load Linearity of Analog output is wrong where charge>500fC

From now… Correlation with neighbor strips Try to Change HV or Gas mixture Time Response Leading edge fluctuation from ion drift time<100nsec ENC 2000electrons for 300pF ～ 0.3fC Requirement is less than 1% Can we get 100um resolution with ASD Chip?