Difference between revisions of "CDC 50 50"

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|+ Drift time for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(t4sig)-17, tz_add=0  
+
|+ Drift time for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(5sig)-17, tz_add=0  
 
|[[Image:run_31809_np17_thr5_20.png|thumb|x350px|2090V, hit threshold 5sigma, time thresholds 4 and 1 sigma
 
|[[Image:run_31809_np17_thr5_20.png|thumb|x350px|2090V, hit threshold 5sigma, time thresholds 4 and 1 sigma
 
Estimate of t0 is 88 and tmax is 756, difference is 668, straight-line intercept is 79.2, to match histogram fit t0, use tz_add 8.4
 
Estimate of t0 is 88 and tmax is 756, difference is 668, straight-line intercept is 79.2, to match histogram fit t0, use tz_add 8.4
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{| border="0" cellpadding="2"  
 
{| border="0" cellpadding="2"  
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|+ Resolution for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(t4sig)-17, tz_add=8, 50/50 Garfield  
+
|+ Resolution for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(5sig)-17, tz_add=8, 50/50 Garfield  
 
|[[Image:run_31809_np17_tz8_res20.png|thumb|x250px|50/50 Garfield, resolution ch 20]]
 
|[[Image:run_31809_np17_tz8_res20.png|thumb|x250px|50/50 Garfield, resolution ch 20]]
 
|[[Image:run_31809_np17_tz8_resx20.png|thumb|x250px|50/50 Garfield, resolution vs hit radius]]
 
|[[Image:run_31809_np17_tz8_resx20.png|thumb|x250px|50/50 Garfield, resolution vs hit radius]]
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{| border="0" cellpadding="2"  
 
{| border="0" cellpadding="2"  
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|+ Resolution for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(t4sig)-17, tz_add=8, 49.5/50.5 Garfield  
+
|+ Resolution for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(5sig)-17, tz_add=8, 49.7/50.3 Garfield
 +
|[[Image:run_31809_497503_np17_tz8_res20.png|thumb|x250px|49.7/50.3 Garfield, resolution ch 20]]
 +
|[[Image:run_31809_497503_np17_tz8_resx20.png|thumb|x250px|49.7/50.3 Garfield, resolution vs hit radius]]
 +
|[[Image:run_31809_497503_np17_tz8_res20_5mm.png|thumb|x250px|49.7/50.3 Garfield, resolution ch 20 for tracks of radius 5mm+]]
 +
|}
 +
 
 +
{| border="0" cellpadding="2"
 +
|+ Resolution for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(5sig)-17, tz_add=8, 49.5/50.5 Garfield  
 
|[[Image:run_31809_495505_np17_tz8_res20.png|thumb|x250px|49.5/50.5 Garfield, resolution ch 20]]
 
|[[Image:run_31809_495505_np17_tz8_res20.png|thumb|x250px|49.5/50.5 Garfield, resolution ch 20]]
 
|[[Image:run_31809_495505_np17_tz8_resx20.png|thumb|x250px|49.5/50.5 Garfield, resolution vs hit radius]]
 
|[[Image:run_31809_495505_np17_tz8_resx20.png|thumb|x250px|49.5/50.5 Garfield, resolution vs hit radius]]
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{| border="0" cellpadding="2"  
 
{| border="0" cellpadding="2"  
−
|+ Resolution for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(t4sig)-17, tz_add=8, 50/50 Garfield  
+
|+ Resolution for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(5sig)-17, tz_add=8, 50/50 Garfield  
 
|[[Image:run_31809_np17_tz8_xchunks.png|thumb|x250px|50/50 Garfield, resolution vs track radius]]
 
|[[Image:run_31809_np17_tz8_xchunks.png|thumb|x250px|50/50 Garfield, resolution vs track radius]]
 
|[[Image:run_31809_np17_tz8_xchunks3.png|thumb|x250px|50/50 Garfield, resolution vs track radius]]
 
|[[Image:run_31809_np17_tz8_xchunks3.png|thumb|x250px|50/50 Garfield, resolution vs track radius]]
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{| border="0" cellpadding="2"  
 
{| border="0" cellpadding="2"  
−
|+ Resolution for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(t4sig)-17, tz_add=8, 49.5/50.5 Garfield  
+
|+ Resolution for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(5sig)-17, tz_add=8, 49.7/50.3 Garfield
 +
|[[Image:run_31809_497503_np17_tz8_xchunks.png|thumb|x250px|49.7/50.3 Garfield, resolution vs track radius]]
 +
|[[Image:run_31809_497503_np17_tz8_xchunks8.png|thumb|x250px|49.7/50.3 Garfield, resolution vs track radius]]
 +
|}
 +
 
 +
 
 +
{| border="0" cellpadding="2"
 +
|+ Resolution for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(5sig)-17, tz_add=8, 49.5/50.5 Garfield  
 
|[[Image:run_31809_495505_np17_tz8_xchunks.png|thumb|x250px|49.5/50.5 Garfield, resolution vs track radius]]
 
|[[Image:run_31809_495505_np17_tz8_xchunks.png|thumb|x250px|49.5/50.5 Garfield, resolution vs track radius]]
 
|[[Image:run_31809_495505_np17_tz8_xchunks8.png|thumb|x250px|49.5/50.5 Garfield, resolution vs track radius]]
 
|[[Image:run_31809_495505_np17_tz8_xchunks8.png|thumb|x250px|49.5/50.5 Garfield, resolution vs track radius]]
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<div style="background-color:gray">
 
<div style="background-color:gray">
  
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This does not look nearly as good as 50/50 gas mix.
 
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Resolution is calculated as fitted drift distance - measured (interpolated) distance, so it is positive when the measured drift time and distance are too small.
 
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In this case they are slightly too small at small drift distance but too large at large drift distance. This could be a problem with the gas mix.  For reference, plot res vs distance for tz=5,7,and 0.
 
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−
 
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{| border="0" cellpadding="2"
 
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|+ Resolution for 1975V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(t4sig)-13, tz_add=8, 60/40 Garfield
 
−
|[[Image:run_31842_res20_tz8_6040.png|thumb|x250px|1975V, resolution ch 20]]
 
−
|[[Image:run_31842_resx20_tz8_6040.png|thumb|x250px|1975V, resolution vs hit radius]]
 
−
|}
 
−
Increasing tz_add to 8ns shifts the resolution up at earlier times but it hardly moves at later times.  This would probably have been obvious from the tz=0 data (below) where all the measured drift distances are too large.  "Measured" drift distances are actually interpolated from a table of distance calculated for a given gas mix and a range of time measurements.  So for this data I should use Garfield tables for a gas mix with slower drift velocity, ie less Ar.
 
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{| border="0" cellpadding="2"
 
−
|+ Resolution for 1975V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(t4sig)-13, tz_add=0, 60/40 Garfield
 
−
|[[Image:run_31842_res20_tz0_6040.png|thumb|x250px|1975V, resolution ch 20]]
 
−
|[[Image:run_31842_resx20_tz0_6040.png|thumb|x250px|1975V, resolution vs hit radius]]
 
−
|}
 
−
 
−
 
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Suspect total flow of 60sccm might be too low for the CO2 MFC.  Increase to 80sccm and repeat. Also try Garfield for different gas mixes and look at tmax.
 
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Fitted Tmax was 573, edge is from 560 to 600ns. Garfield calcs give 560ns for 60/40, 573ns (ta-daa!) for 59/41, 588ns for 28/42 and 610ns for 57/43.
 
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It's easiest to look at resolution far from the wire to find the best gas mix model. 
 
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{| border="0" cellpadding="2"
 
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|+ Resolution for 1975V, drift time > 240ns (~approx 5mm), different gas mix in Garfield, same thresholds and pedestal as before, tz_add=6ns
 
−
|[[Image:run_31842_res20_5mm_6040_tz6.png|thumb|x250px|60/40]]
 
−
|[[Image:run_31842_res20_5mm_5941_tz6.png|thumb|x250px|59/41]]
 
−
|[[Image:run_31842_res20_5mm_585415_tz6.png|thumb|x250px|58.5/41.5]]
 
−
|[[Image:run_31842_res20_5mm_5842_tz6.png|thumb|x250px|58/42]]
 
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|}
 
−
 
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{| border="0" cellpadding="2"
 
−
|+ Resolution for 1975V, same thresholds and pedestal as before, tz_add=6ns, 58.5/41.5 Garfield
 
−
|[[Image:run_31842_res20_tz6_585_415.png|thumb|x250px|1975V, resolution ch 20]]
 
−
|[[Image:run_31842_resx20_tz6_585_415.png|thumb|x250px|1975V, resolution vs hit radius]]
 
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|}
 
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Now look at timing.  Where to take local pedestal.  These are plots of change in ADC value vs time relative to the threshold crossing time.
 
−
Nothing to do with Garfield or tz_add but already have a good default in place (take pedestal at np=13 minisamples before threshold crossing) so small changes here are a fine tuning.
 
 
{| border="0" cellpadding="2"  
 
{| border="0" cellpadding="2"  
 
|+ 1975V 59/41 Garfield etc Change in ADC value vs time relative to the threshold crossing time (in units of 8ns/5)
 
|+ 1975V 59/41 Garfield etc Change in ADC value vs time relative to the threshold crossing time (in units of 8ns/5)

Revision as of 14:16, 16 October 2012

The later part of this page is 60/40 being used as a template for the 50/50. New stuff (50/50) is above the line.

50/50 Ar/CO2 and cosmics, prototype horizontal

2050V, 50/50 gas, prototype horizontal
Pedestal mean of samples 0-99, ch20, over 1 day
Pedestal std. dev. of samples 0-99, ch20, over 1 day
Max amplitude ch20, hit threshold 4sigma
Max amplitude ch20, hit threshold 5sigma
2075V, 50/50 gas, prototype horizontal
Pedestal mean of samples 0-99, ch20, over 1 day
Pedestal std. dev. of samples 0-99, ch20, over 1 day
Max amplitude ch20, hit threshold 4sigma, excluding last 7k events
Max amplitude ch20, hit threshold 5sigma, excluding last 7k events


2100V, 50/50 gas, prototype horizontal
Pedestal mean of samples 0-99, ch20, over 1 day
Pedestal std. dev. of samples 0-99, ch20, over 1 day
Max amplitude ch20, hit threshold 4sigma, excluding first 2k events
Max amplitude ch20, hit threshold 5sigma, excluding first 2k events


2090V, 50/50 gas, prototype horizontal
Pedestal mean of samples 0-99, ch20, over 1 day
Pedestal std. dev. of samples 0-99, ch20, over 1 day
Max amplitude ch20, hit threshold 4sigma
Max amplitude ch20, hit threshold 5sigma

Where to start the fit from.

50/50 gas, prototype horizontal, 4sigma (gray) and 5sigma (blue) hit threshold, fit range 6sigma+
2090V, Landau fits, log likelihood method, fit range starting at 5, 6, 7, 8 x pedestal sigma
2090V, zoomed in

The fits started at higher amplitude underestimate the width. Fit range starting at 5pedestalsigma has MPV 204.5, Sigma 61.9, MPV/Sigma 3.3. Fit range starting at 6pedestalsigma has MPV 208.6, Sigma 60.7, MPV/Sigma 3.4. Fit range starting at 7pedestalsigma has MPV 213.7, Sigma 59.5, MPV/Sigma 3.6. Use 5pedestalsigma start.


50/50 gas, prototype horizontal, 4sigma (gray) and 5sigma (blue) hit threshold, fit range 5sigma+
2075V, lines show 99.7%, 99% and 95% of landau summed 0-4000 (51, 66, 95)
2090V, lines show 99.7%, 99% and 95% of landau summed 0-4000 (55, 74, 111)
2100V, lines show 99.7%, 99% and 95% of landau summed 0-4000 (59, 80, 121)



50/50 gas, noise std dev 16.5, hit threshold 5x16.5 = 82.5
HV Fit MPV Fit sigma (FWHM/4) Fit 4sigma/MPV MPV/sigma 4045/MPV 99% point 97% point 95% point
2075 169 49 1.16 3.5 24 66 84 95
2090 204 62 1.21 3.3 20 74 97 111
2100 225 69 1.22 3.3 18 80 106 122

Find out where to take local pedestal. These are plots of change in ADC value vs time relative to the threshold crossing time. Nothing to do with Garfield or tz_add but already have a good default in place (take pedestal at np=13 minisamples before threshold crossing) so small changes here are a fine tuning.

2090V 50/50 Change in ADC value vs time relative to the threshold crossing time (in units of 8ns/5)
2090V, hit thr 5 ped-sigma

Mean goes through 0.5 and 1 at -17.2 and -14.4 for thr=5sigma

Drift time for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(5sig)-17, tz_add=0
2090V, hit threshold 5sigma, time thresholds 4 and 1 sigma Estimate of t0 is 88 and tmax is 756, difference is 668, straight-line intercept is 79.2, to match histogram fit t0, use tz_add 8.4
Same, x-axis expanded

Max drift time according to Garfield is 663ns for 50/50 Ar/CO2, 671ns for 49.5/50.5, 678ns for 49/51.

Resolution for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(5sig)-17, tz_add=8, 50/50 Garfield
50/50 Garfield, resolution ch 20
50/50 Garfield, resolution vs hit radius
50/50 Garfield, resolution ch 20 for tracks of radius 5mm+
Resolution for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(5sig)-17, tz_add=8, 49.7/50.3 Garfield
49.7/50.3 Garfield, resolution ch 20
49.7/50.3 Garfield, resolution vs hit radius
49.7/50.3 Garfield, resolution ch 20 for tracks of radius 5mm+
Resolution for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(5sig)-17, tz_add=8, 49.5/50.5 Garfield
49.5/50.5 Garfield, resolution ch 20
49.5/50.5 Garfield, resolution vs hit radius
49.5/50.5 Garfield, resolution ch 20 for tracks of radius 5mm+
Resolution for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(5sig)-17, tz_add=8, 50/50 Garfield
50/50 Garfield, resolution vs track radius
50/50 Garfield, resolution vs track radius
Resolution for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(5sig)-17, tz_add=8, 49.7/50.3 Garfield
49.7/50.3 Garfield, resolution vs track radius
49.7/50.3 Garfield, resolution vs track radius


Resolution for 2090V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(5sig)-17, tz_add=8, 49.5/50.5 Garfield
49.5/50.5 Garfield, resolution vs track radius
49.5/50.5 Garfield, resolution vs track radius



The later part of this page is 60/40 being used as a template for the 50/50. New stuff (50/50) is above the line.

1975V 59/41 Garfield etc Change in ADC value vs time relative to the threshold crossing time (in units of 8ns/5)
1975V, hit thr 5 ped-sigma
1975V, hit thr 6 ped-sigma

Mean goes through 0.5 and 1 at -16.4 and -13.7 for thr=5sigma, -17.6 and -14.9 for thr=6sigma

1975V 58.5/41.5 Garfield etc Resolution for different local pedestal points, tz_add=6ns
10, 15, and 20 points (1.6ns each) before hit threshold
15, 16, and 17 points (1.6ns each) before hit threshold


1975V 58.5/41.5 Garfield etc Resolution for different local pedestal points, tz_add=7ns
10, 15, and 20 points (1.6ns each) before hit threshold
15, 16, and 17 points (1.6ns each) before hit threshold


Resolution for 1975V, 58.5/41.5 Garfield, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(t4sig)-16, tz_add=7ns, tfix=1000
1975V, resolution ch 20
1975V, resolution vs hit radius

Now include previously ignored hits which arrived before tzero+tz_add, assign these to a fixed drift time

1975V 58.5/41.5 Garfield etc Resolution for np=16, tz_add=7ns, early hits assigned to 0ns, 1ns, 2ns
tfix = 0, 1, 2ns


Resolution for 1975V, 58.5/41.5 Garfield, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(t4sig)-16, tz_add=7ns, tfix=1ns
1975V, resolution ch 20
1975V, resolution vs hit radius
Resolution for 1975V, 58.5/41.5 Garfield, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(t4sig)-16, tz_add=7ns, tfix=2ns
1975V, resolution ch 20
1975V, resolution vs hit radius
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