Difference between revisions of "CDC time spikes"

Revision as of 10:04, 15 November 2012

Prototype at 2100V, 50/50 Ar/CO2

Tilted detectors

Trigger signals

Scint and coinc logic signals, scope triggered on coinc (magenta)

Same, with TI busy signal (green)

Same, different timebase

Histograms of threshold-crossing bins in central bank of 16 straws, different thresholds (ignore the histo titles)

ADC-value=150 crossing (~approx ped + 5sigma)

3.5sigma crossing (approx ADC value 112 = (55 + 3x16.5))

ADC-value=100 crossing

Histograms of ADC value=100 threshold-crossing bins in individual straws (search started at bin 160)

ADC-value=100 crossing

2-d histograms of ADC value=100 threshold-crossing bins in each straw vs same for one particular straw

straw 0

straw 1

straw 2

Same data after more normal analysis (Search forward to find pedestal+5sigma crossing, then backwards to find 4sigma and then 1sigma crossings)

5sigma crossing

4sigma crossing

1sigma crossing

extrapolation to local pedestal crossing

drift time (ns)

Noise run (triggered on 20us pulser) ADC=100 crossing bins

ADC=100 crossing bin, triggered on pulser

3.5sigma crossing bin, triggered on pulser

5sigma crossing bin, triggered on pulser

Noise run (triggered on scintillator when prototype was not above/beneath it) ADC=100 crossing bins

ADC=100 crossing bin, random trigger

3.5sigma crossing bin, random trigger

5sigma crossing bin, random trigger