Difference between revisions of "ASIC design optimizations"
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− | == | + | == Traces of cosmic rays in coincidence with the scintillators == |
+ | Here's how the trigger's formed: | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:trigger form.jpg|thumb|none|400px|Trigger formation.]] | ||
+ | |- | ||
+ | |} | ||
− | |||
− | |||
− | |||
+ | Here are some infinite persistence traces: | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:comics1.jpg|thumb|none|400px|Traces of straight cosmics.]] | ||
+ | |width="415pt"|[[Image:cosmics2.jpg|thumb|none|400px|Traces of straight cosmics.]] | ||
+ | |- | ||
+ | |} | ||
− | * (absolute) Gas gain | + | |
+ | Here are some infinite persistence traces: | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:comics1a.jpg|thumb|none|400px|Traces of straight cosmics.]] | ||
+ | |width="415pt"|[[Image:cosmics2a.jpg|thumb|none|400px|Traces of straight cosmics.]] | ||
+ | |width="415pt"|[[Image:cosmics3a.jpg|thumb|none|400px|Traces of straight cosmics.]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | == Fe-55 measurements == | ||
+ | |||
+ | === Cross talk === | ||
+ | |||
+ | To have a quick look concerning cross talk let's show some scatter plots: | ||
+ | |||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:2fe55-begins3.jpg|thumb|none|400px|Fe-55 peak amplitude spectrum (1800 V - begin - upper ).]] | ||
+ | |width="415pt"|[[Image:nextcross.jpg|thumb|none|400px|The straw next to it.]] | ||
+ | |width="415pt"|[[Image:undercross.jpg|thumb|none|400px|The straw underneath it.]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:elnext.jpg|thumb|none|400px|The electronic channel next to it.]] | ||
+ | |width="415pt"|[[Image:elnext2.jpg|thumb|none|400px|The other electronic channel next to it.]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | There is some electronic cross talk. | ||
+ | |||
+ | === Raw fADC spectra=== | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:rawsignal1.jpg|thumb|none|400px|Raw fADC spectrum (1800 V - end - upper ).]] | ||
+ | |width="415pt"|[[Image:rawsignal2.jpg|thumb|none|400px|Raw fADC spectrum (1800 V - end - upper ).]] | ||
+ | |width="415pt"|[[Image:rawsignal3.jpg|thumb|none|400px|Raw fADC spectrum (1800 V - end - upper ).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ADC-channel versus time(ns) | ||
+ | |||
+ | Upper means the straw that does not need extra support. | ||
+ | |||
+ | === "Energy" spectra=== | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:energy-1750.jpg|thumb|none|400px|"Energy" spectrum (1750 V - begin - upper ).]] | ||
+ | |width="415pt"|[[Image:energy-1800.jpg|thumb|none|400px|"Energy" spectrum (1800 V - begin - upper ).]] | ||
+ | |width="415pt"|[[Image:energy-1850.jpg|thumb|none|400px|"Energy" spectrum (1850 V - begin - upper ).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | High statistics run: | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:energy-1800-hs.jpg|thumb|none|400px|"Energy" spectrum (1800 V - begin - upper ).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | |||
+ | x-axis is in ADC channels | ||
+ | |||
+ | This measurements correspond with the three measurements with different HV on the straw that does not need extra support. | ||
+ | |||
+ | === Different HV (Straw supported): === | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:fe55-1750s.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1750 V - begin).]] | ||
+ | |width="415pt"|[[Image:fe55-1800s.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1800 V - begin).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | Different positions (straw supported,1800V): | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:fe55-1800s.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1800 V - begin).]] | ||
+ | |width="415pt"|[[Image:fe55-middles.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1800 V - middle).]] | ||
+ | |width="415pt"|[[Image:fe55-ends.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1800 V - end).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | |||
+ | Different HV (Straw not supported) | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:fe55-1700ns.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1700 V - begin).]] | ||
+ | |width="415pt"|[[Image:fe55-1800ns.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1800 V - begin).]] | ||
+ | |width="415pt"|[[Image:fe55-1850ns.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1850 V - begin).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | |||
+ | |||
+ | Are the measurements reproduce-able? | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:fe55-1800s2.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1800 V - begin - supported).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | supported/not supported (middle) + TILTED (55 degrees) | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:fe55-middle-s.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1800 V - middle - supported).]] | ||
+ | |width="415pt"|[[Image:fe55-middle-ns.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1800 V - middle - not supported).]] | ||
+ | |width="415pt"|[[Image:fe55-middle-tilted.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1800 V - middle - 55 degree tilted).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | |||
+ | |||
+ | What about measuring another straw (one that does not need support - and does not have dead spots): | ||
+ | Different positions (1800V): | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:2fe55-begins.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1800 V - begin).]] | ||
+ | |width="415pt"|[[Image:2fe55-middles.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1800 V - middle).]] | ||
+ | |width="415pt"|[[Image:2fe55-ends.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1800 V - end).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | Reproduce-able?: | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:2fe55-begins2.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1800 V - begin).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | Different-HV: | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:2fe55-1750.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1750 V - begin).]] | ||
+ | |width="415pt"|[[Image:2fe55-begins2.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1800 V - begin).]] | ||
+ | |width="415pt"|[[Image:2fe55-180.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1850 V - begin).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | |||
+ | To finish a high statistics run: | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:2fe55-begins3.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1800 V - begin - high statistics).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | == Chamber at 0 degrees == | ||
+ | * Measurements with the 55-Fe source | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:fe55-1750.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1750 V - low threshold).]] | ||
+ | |width="415pt"|[[Image:fe55-1800.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (1800 V - low threshold).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:bestfe55.jpg|thumb|none|400px|Amplitude spectrum measured with the 55-Fe source (high threshold - 1800 V).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | |||
+ | |||
+ | * High Voltage plateau === done | ||
+ | Gas: Ar-CO2 87%-13% gas mixture. | ||
+ | Setup: the signal after the shaper was inverted and fed to a discriminator. The HV was changed and the signals above threshold where counted (normalized to 100s measure time). | ||
+ | Update: results with 3,4,5 sigma pedestal cuts: | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hvplateau3s.jpg|thumb|none|400px|HV-curve - 3sigma cut, tracked events, normalized to a 40' measurements.]] | ||
+ | |width="415pt"|[[Image:hvplateau4s.jpg|thumb|none|400px|HV-curve - 4sigma cut, tracked events, normalized to a 40' measurement.]] | ||
+ | |width="415pt"|[[Image:hvplateau5s.jpg|thumb|none|400px|HV-curve - 5sigma cut, tracked events, normalized to a 40' measurement.]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | The pedestal means (the error bar is the pedestal width): | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hvplateau-noise.jpg|thumb|none|400px|HV-noise-curve - Pedestal mean as a function of applied HV, the error bars represent the pedestal width]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | The result: | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hvplateau_ch15.jpg|thumb|none|400px|HV-curve,the count is normalized to 100s measurements.]] | ||
+ | |width="415pt"|[[Image:hvplateau2_ch4.jpg|thumb|none|400px|HV-curve-plateau, tracked events, normalized to a 40' measurement.]] | ||
+ | |- | ||
+ | |} | ||
+ | So things start to show up (above threshold, the threshold was set just above noise) at 1500 V and start to break down at +2000V. We see a plateau starting at 1750V. All hv-plateaus are ahown in following figure: | ||
+ | [[Image:plateaus.jpg|thumb|none|830px|All hv-plateaus.]] | ||
+ | |||
+ | |||
+ | Next the scope traces of the (maximum) noise level after the shaper is shown on the left side. This pickup happens mostly on a different time then a signal. The right side shows a signal at 1800V, also after the shaper. To trigger on the signal I set the threshold to 350 mV. | ||
+ | |||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:trace-noise_after_shaper.jpg|thumb|none|400px|Trace of maximum noise after shaper.]] | ||
+ | |width="415pt"|[[Image:trace-1800V_after_shaper.jpg|thumb|none|400px|Trace of a signal at 1800 V after the shaper.]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | Let's compare signals at different stages in the electronics chain. Left plot is the signal right BEFORE the pre-amplifier, middle plot is the signal AFTER the pre-amplifier (0.366 times attenuated because of the differential probe), right plot is AFTER the shaper. | ||
+ | |||
+ | ** The noise | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|Noise before preAmp is dominated by the noise pickup of the probe. | ||
+ | |width="415pt"|[[Image:trace-noise-preAmp.jpg|thumb|none|400px|Noise after preAmp.]] | ||
+ | |width="415pt"|[[Image:trace-noise_after_shaper.jpg|thumb|none|400px|Noise after shaper.]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | |||
+ | ** 1600V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|N/A because of noisy probe. | ||
+ | |width="415pt"|[[Image:trace-1600V-preAmp.jpg|thumb|none|400px|Trace of signal after preAmp of channel 2.]] | ||
+ | |width="415pt"|[[Image:hv-1600-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1700V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|N/A because of noisy probe. | ||
+ | |width="415pt"|[[Image:trace-1700V-preAmp.jpg|thumb|none|400px|Trace of signal after preAmp of channel 2.]] | ||
+ | |width="415pt"|[[Image:hv-1700-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1750V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:trace-1750V-CDC.jpg|thumb|none|400px|Trace of signal before preAmp of channel 2.]] | ||
+ | |width="415pt"|[[Image:trace-1750V-preAmp.jpg|thumb|none|400px|Trace of signal after preAmp of channel 2.]] | ||
+ | |width="415pt"|[[Image:hv-1750-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1800V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:trace-1800V-CDC.jpg|thumb|none|400px|Trace of signal before preAmp of channel 2.]] | ||
+ | |width="415pt"|[[Image:trace-1800V-preAmp.jpg|thumb|none|400px|Trace of signal after preAmp of channel 2.]] | ||
+ | |width="415pt"|[[Image:hv-1800-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1900V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:trace-1900V-CDC.jpg|thumb|none|400px|Trace of signal before preAmp of channel 2.]] | ||
+ | |width="415pt"|[[Image:trace-1900V-preAmp.jpg|thumb|none|400px|Trace of signal after preAmp of channel 2.]] | ||
+ | |width="415pt"|[[Image:hv-1900-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1950V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:trace-1950V-CDC.jpg|thumb|none|400px|Trace of signal before preAmp of channel 2.]] | ||
+ | |width="415pt"|[[Image:trace-1950V-preAmp.jpg|thumb|none|400px|Trace of signal after preAmp of channel 2.]] | ||
+ | |width="415pt"|[[Image:hv-1950-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 2000V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:trace-2000V-CDC.jpg|thumb|none|400px|Trace of signal before preAmp of channel 2.]] | ||
+ | |width="415pt"|[[Image:trace-2000V-preAmp.jpg|thumb|none|400px|Trace of signal after preAmp of channel 2.]] | ||
+ | |width="415pt"|[[Image:hv-2000-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | |||
+ | What exactly does the shaper? Well you can see this in following traces: from left to right: three signals before/after (green/red) the shaper @ 1800 V: | ||
+ | (remember that the signal before the shaper is attenuated (0.336x) ) | ||
+ | |||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:1800ampshaper-1.jpg|thumb|none|400px|Trace of signal before/after (green/red) shaper.]] | ||
+ | |width="415pt"|[[Image:1800ampshaper-2.jpg|thumb|none|400px|Trace of signal before/after (green/red) shaper.]] | ||
+ | |width="415pt"|[[Image:1800ampshaper-3.jpg|thumb|none|400px|Trace of signal before/after (green/red) shaper.]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | The same measurement was performed but now with two probes measuring the differential input signal and MATH function on the scope. Here are three scope traces: | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:trace1.jpg|thumb|none|400px|Trace of signal before/after (purple/black) shaper.]] | ||
+ | |width="415pt"|[[Image:trace2.jpg|thumb|none|400px|Trace of signal before/after (purple/black) shaper.]] | ||
+ | |width="415pt"|[[Image:trace3.jpg|thumb|none|400px|Trace of signal before/after (purple/black) shaper.]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | Below galleries of pulses are shown for different HV (on the left channel 2, in the middle channel 15) -- remember everything above 1V is an overflow on the fADC, also the b/w traces are taken with infinite persistence, the colored ones with 10 s persistence. The amplitude spectra are also shown: notice the growing overflow peak around channel 3000 (they are pedestal subtracted): | ||
+ | ** 1600 V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hv-1600-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |width="415pt"|[[Image:hv-1600-ch15.jpg|thumb|none|400px|Gallery of pulses of channel 15.]] | ||
+ | |width="415pt"|[[Image:hv-1600-amp-ch15.jpg|thumb|none|400px|Amplitude spectrum of ch 15 (counts versus amplitude in ADC channels, with shaper).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1650 V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hv-1650-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |width="415pt"|[[Image:hv-1650-ch15.jpg|thumb|none|400px|Gallery of pulses of channel 15.]] | ||
+ | |width="415pt"|[[Image:hv-1650-amp-ch15.jpg|thumb|none|400px|Amplitude spectrum of ch 15 (counts versus amplitude in ADC channels, with shaper).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1700 V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hv-1700-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |width="415pt"|[[Image:hv-1700-ch15.jpg|thumb|none|400px|Gallery of pulses of channel 15.]] | ||
+ | |width="415pt"|[[Image:hv-1700-amp-ch15.jpg|thumb|none|400px|Amplitude spectrum of ch 15 (counts versus amplitude in ADC channels, with shaper).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1750 V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hv-1750-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |width="415pt"|[[Image:hv-1750-ch15.jpg|thumb|none|400px|Gallery of pulses of channel 15.]] | ||
+ | |width="415pt"|[[Image:hv-1750-amp-ch15.jpg|thumb|none|400px|Amplitude spectrum of ch 15 (counts versus amplitude in ADC channels, with shaper).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1800 V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hv-1800-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |width="415pt"|[[Image:hv-1800-ch15.jpg|thumb|none|400px|Gallery of pulses of channel 15.]] | ||
+ | |width="415pt"|[[Image:hv-1800-amp-ch15.jpg|thumb|none|400px|Amplitude spectrum of ch 15 (counts versus amplitude in ADC channels, with shaper).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1850 V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hv-1850-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |width="415pt"|[[Image:hv-1850-ch15.jpg|thumb|none|400px|Gallery of pulses of channel 15.]] | ||
+ | |width="415pt"|[[Image:hv-1850-amp-ch15.jpg|thumb|none|400px|Amplitude spectrum of ch 15 (counts versus amplitude in ADC channels, with shaper).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1900 V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hv-1900-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |width="415pt"|[[Image:hv-1900-ch15.jpg|thumb|none|400px|Gallery of pulses of channel 15.]] | ||
+ | |width="415pt"|[[Image:hv-1900-amp-ch15.jpg|thumb|none|400px|Amplitude spectrum of ch 15 (counts versus amplitude in ADC channels, with shaper).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1950 V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hv-1950-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |width="415pt"|[[Image:hv-1950-ch15.jpg|thumb|none|400px|Gallery of pulses of channel 15.]] | ||
+ | |width="415pt"|[[Image:hv-1950-amp-ch15.jpg|thumb|none|400px|Amplitude spectrum of ch 15 (counts versus amplitude in ADC channels, with shaper).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 2000 V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hv-2000-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |width="415pt"|[[Image:hv-2000-ch15.jpg|thumb|none|400px|Gallery of pulses of channel 15.]] | ||
+ | |width="415pt"|[[Image:hv-2000-amp-ch15.jpg|thumb|none|400px|Amplitude spectrum of ch 15 (counts versus amplitude in ADC channels, with shaper).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | == Chamber at 60 degrees == | ||
+ | [[Image:tilted.jpg|thumb|none|400px|]] | ||
+ | |||
+ | Below you can find some pulse galleries and amplitude spectra (low statistics) | ||
+ | |||
+ | |||
+ | ** 1600 V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hvtilt-1600-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |width="415pt"|[[Image:hvtilt-1600-ch15.jpg|thumb|none|400px|Gallery of pulses of channel 15.]] | ||
+ | |width="415pt"|[[Image:hv-1600-amptilt-ch15.jpg|thumb|none|400px|Amplitude spectrum of ch 15 (counts versus amplitude in ADC channels, with shaper).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1650 V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hvtilt-1650-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |width="415pt"|[[Image:hvtilt-1650-ch15.jpg|thumb|none|400px|Gallery of pulses of channel 15.]] | ||
+ | |width="415pt"|[[Image:hv-1650-amptilt-ch15.jpg|thumb|none|400px|Amplitude spectrum of ch 15 (counts versus amplitude in ADC channels, with shaper).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1700 V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hvtilt-1700-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |width="415pt"|[[Image:hvtilt-1700-ch15.jpg|thumb|none|400px|Gallery of pulses of channel 15.]] | ||
+ | |width="415pt"|[[Image:hv-1700-amptilt-ch15.jpg|thumb|none|400px|Amplitude spectrum of ch 15 (counts versus amplitude in ADC channels, with shaper).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1750 V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hvtilt-1750-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |width="415pt"|[[Image:hvtilt-1750-ch15.jpg|thumb|none|400px|Gallery of pulses of channel 15.]] | ||
+ | |width="415pt"|[[Image:hv-1750-amptilt-ch15.jpg|thumb|none|400px|Amplitude spectrum of ch 15 (counts versus amplitude in ADC channels, with shaper).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1800 V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hvtilt-1800-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |width="415pt"|[[Image:hvtilt-1800-ch15.jpg|thumb|none|400px|Gallery of pulses of channel 15.]] | ||
+ | |width="415pt"|[[Image:hv-1800-amptilt-ch15.jpg|thumb|none|400px|Amplitude spectrum of ch 15 (counts versus amplitude in ADC channels, with shaper).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1850 V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hvtilt-1850-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |width="415pt"|[[Image:hvtilt-1850-ch15.jpg|thumb|none|400px|Gallery of pulses of channel 15.]] | ||
+ | |width="415pt"|[[Image:hv-1850-amptilt-ch15.jpg|thumb|none|400px|Amplitude spectrum of ch 15 (counts versus amplitude in ADC channels, with shaper).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1900 V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hvtilt-1900-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |width="415pt"|[[Image:hvtilt-1900-ch15.jpg|thumb|none|400px|Gallery of pulses of channel 15.]] | ||
+ | |width="415pt"|[[Image:hv-1900-amptilt-ch15.jpg|thumb|none|400px|Amplitude spectrum of ch 15 (counts versus amplitude in ADC channels, with shaper).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 1950 V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hvtilt-1950-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |width="415pt"|[[Image:hvtilt-1950-ch15.jpg|thumb|none|400px|Gallery of pulses of channel 15.]] | ||
+ | |width="415pt"|[[Image:hv-1950-amptilt-ch15.jpg|thumb|none|400px|Amplitude spectrum of ch 15 (counts versus amplitude in ADC channels, with shaper).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | ** 2000 V | ||
+ | {| border="1" cellpadding="2" | ||
+ | |- | ||
+ | |width="415pt"|[[Image:hvtilt-2000-ch2.jpg|thumb|none|400px|Gallery of pulses of channel 2.]] | ||
+ | |width="415pt"|[[Image:hvtilt-2000-ch15.jpg|thumb|none|400px|Gallery of pulses of channel 15.]] | ||
+ | |width="415pt"|[[Image:hv-2000-amptilt-ch15.jpg|thumb|none|400px|Amplitude spectrum of ch 15 (counts versus amplitude in ADC channels, with shaper).]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | == To Do == | ||
+ | |||
+ | * (absolute) Gas gain as a function of High Voltage | ||
Source measurement using Sr-90 (e-) or 55-Fe (X-rays) (if we have it) / or using cosmic rays? | Source measurement using Sr-90 (e-) or 55-Fe (X-rays) (if we have it) / or using cosmic rays? | ||
− | -- Estimated time: 1 day | + | -- Estimated time: 1 day -- if we have a good source |
− | * | + | * amplitude distributions of tilted chamber |
− | + | 1 week measure with tilted chamber => In progress | |
− | + | ||
− | + | ||
Latest revision as of 15:24, 7 August 2008
Contents
Traces of cosmic rays in coincidence with the scintillators
Here's how the trigger's formed:
Here are some infinite persistence traces:
Here are some infinite persistence traces:
Fe-55 measurements
Cross talk
To have a quick look concerning cross talk let's show some scatter plots:
There is some electronic cross talk.
Raw fADC spectra
ADC-channel versus time(ns)
Upper means the straw that does not need extra support.
"Energy" spectra
High statistics run:
x-axis is in ADC channels
This measurements correspond with the three measurements with different HV on the straw that does not need extra support.
Different HV (Straw supported):
Different positions (straw supported,1800V):
Different HV (Straw not supported)
Are the measurements reproduce-able?
supported/not supported (middle) + TILTED (55 degrees)
What about measuring another straw (one that does not need support - and does not have dead spots): Different positions (1800V):
Reproduce-able?:
Different-HV:
To finish a high statistics run:
Chamber at 0 degrees
- Measurements with the 55-Fe source
- High Voltage plateau === done
Gas: Ar-CO2 87%-13% gas mixture. Setup: the signal after the shaper was inverted and fed to a discriminator. The HV was changed and the signals above threshold where counted (normalized to 100s measure time). Update: results with 3,4,5 sigma pedestal cuts:
The pedestal means (the error bar is the pedestal width):
The result:
So things start to show up (above threshold, the threshold was set just above noise) at 1500 V and start to break down at +2000V. We see a plateau starting at 1750V. All hv-plateaus are ahown in following figure:
Next the scope traces of the (maximum) noise level after the shaper is shown on the left side. This pickup happens mostly on a different time then a signal. The right side shows a signal at 1800V, also after the shaper. To trigger on the signal I set the threshold to 350 mV.
Let's compare signals at different stages in the electronics chain. Left plot is the signal right BEFORE the pre-amplifier, middle plot is the signal AFTER the pre-amplifier (0.366 times attenuated because of the differential probe), right plot is AFTER the shaper.
- The noise
Noise before preAmp is dominated by the noise pickup of the probe. |
- 1600V
N/A because of noisy probe. |
- 1700V
N/A because of noisy probe. |
- 1750V
- 1800V
- 1900V
- 1950V
- 2000V
What exactly does the shaper? Well you can see this in following traces: from left to right: three signals before/after (green/red) the shaper @ 1800 V:
(remember that the signal before the shaper is attenuated (0.336x) )
The same measurement was performed but now with two probes measuring the differential input signal and MATH function on the scope. Here are three scope traces:
Below galleries of pulses are shown for different HV (on the left channel 2, in the middle channel 15) -- remember everything above 1V is an overflow on the fADC, also the b/w traces are taken with infinite persistence, the colored ones with 10 s persistence. The amplitude spectra are also shown: notice the growing overflow peak around channel 3000 (they are pedestal subtracted):
- 1600 V
- 1650 V
- 1700 V
- 1750 V
- 1800 V
- 1850 V
- 1900 V
- 1950 V
- 2000 V
Chamber at 60 degrees
Below you can find some pulse galleries and amplitude spectra (low statistics)
- 1600 V
- 1650 V
- 1700 V
- 1750 V
- 1800 V
- 1850 V
- 1900 V
- 1950 V
- 2000 V
To Do
- (absolute) Gas gain as a function of High Voltage
Source measurement using Sr-90 (e-) or 55-Fe (X-rays) (if we have it) / or using cosmic rays? -- Estimated time: 1 day -- if we have a good source
- amplitude distributions of tilted chamber
1 week measure with tilted chamber => In progress
- Collection of gallery of pulses
I found 4 pulse galleries, measured directly after the pre-amplifier made by Gerard when he was here, they are shown below: