BNL electronics: first tests Progress report 15 Dec 2009, CERN

BNL TPC ASIC IC85 Technology: CMOS 0.25mm – 2.5 V Power 43 mW MiM capacitor and silicide block resistor options Power 43 mW Front-End Channels 32 charge preamplifier 2nd order shaping amplifier peak detector timing detector Integrated calibration capacitor 250 fF (s=0.1%) Shaping time 600 ns Channel gain 15mV/fC to 32mV/fC

ASIC IC85 Time and Amplitude Measuring Chain When an event occurs above threshold the discriminator fires and the peak and timing detectors are enabled At the same time the peak and timing detectors of the two neighbor channels are enabled The events in the three channels are processed for peak amplitude and peak timing The two corresponding voltages are stored for each channel DATA Trigger Ramp Event Shaped pulse Comparator Peak detector Time detector

Timing: Tdelay scan Shown for Tdelay = 150 ns Pulser Amplitude 105 e Trigger Pulser Tdelay s=3.3 mV T, mV

Timing calibration: chip A channel 8 needed 1mV = 3.23 ns

On-chip zero suppression Amplitude Time Trigger ID 3263 13 0.210266 0.424957 14 0.370636 0.437927 15 0.225220 0.412750 3264 3265 0 0.284119 0.457306 1 0.435333 0.418854 2 0.313873 0.450287 3266 3267 … 3281 18 0.206909 0.261841 19 0.902252 0.404968 20 1.113892 0.397491 21 0.597534 0.394440 22 0.304718 0.355682 3282 13 0.225525 0.369110 14 0.406952 0.401764 15 0.382996 0.368195 16 0.225372 0.379486 Automatic recording of neighbor strips when a channel exceeds hardware threshold Strip addresses Empty event Testbeam data file run26 136K triggered events 7.5 Mb ascii would be much smaller in binary

mMega + Double mesh VDmesh 650 V Vmesh 420 V  Low Gain 3·103

Stand alone run26 triggered by scintillators, no silicon Vdreif 1800 V Vtop 1400 V Vbott 750 V Vmesh 420 V chip A chip B Channels 13 1nd 18 are not connected to the chamber

Total number of strips fired in event no clustering Total number of events 2 strip events

2 strip events one of three channels missing Bin 9 – 27 entries in 3 cluster events this channel fired 2807 times There are rare cases when 2 neighbors are missing

Analysis cuts Looking for a single cluster per event Cluster width 3≤width≤6 Timing cuts for a channel with maximum amplitude in a cluster 0.3<time<0.5 Amplitude cut: only hardware cut of 0.35 75 ns no timing calibration built-in ramp

Landau

Summary BNL electronics based on ASIC IC85 tested with a pulser and with the beam at H6 Built-in ramp is very shallow to be replaced with an external one Sparking prevent from running at high gain Each channel to be calibrated separately on both timing and amplitude Plan Event Display Mapping is simple here)) Resolution with Silicon