Difference between revisions of "CDC 60 40"
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60/40 Ar/CO<sub>2</sub> and cosmics, prototype horizontal | 60/40 Ar/CO<sub>2</sub> and cosmics, prototype horizontal | ||
− | + | <h4>Short runs for range of HV, check pedestal is ok and find MPV</h4> | |
{| border="0" cellpadding="2" | {| border="0" cellpadding="2" | ||
|+ 1800V, 60/40 gas, prototype horizontal | |+ 1800V, 60/40 gas, prototype horizontal | ||
Line 40: | Line 40: | ||
|} | |} | ||
− | + | <h4>Fit max amplitude histograms and find optimal HV</h4> | |
{| border="0" cellpadding="2" | {| border="0" cellpadding="2" | ||
|+ 60/40 gas, prototype horizontal, 4sigma (gray) and 5sigma (blue) hit threshold, fit range 6sigma+ | |+ 60/40 gas, prototype horizontal, 4sigma (gray) and 5sigma (blue) hit threshold, fit range 6sigma+ | ||
Line 50: | Line 50: | ||
{| border="1px" cellpadding="2" style="border-style:solid;" | {| border="1px" cellpadding="2" style="border-style:solid;" | ||
− | |+ 60/40 gas, noise std dev 16.5, hit threshold 5x16.5 = 82.5 | + | |+ 60/40 gas, noise std dev 16.5, hit threshold 5x16.5 = 82.5, fit range 6pedestalsigma+ |
! HV | ! HV | ||
! Fit MPV | ! Fit MPV | ||
Line 81: | Line 81: | ||
+ | |||
+ | {| border="0" cellpadding="2" | ||
+ | |+ 60/40 gas, prototype horizontal, 4sigma (gray) and 5sigma (blue) hit threshold, fit range 5sigma+ | ||
+ | |[[Image:run_31838_r5sig_ampfitz.png|thumb|x250px|1950V, lines show 99.7%, 99% and 95% of landau summed 0-4000 (56, 72, 103)]] | ||
+ | |[[Image:run_31840_r5sig_ampfitz.png|thumb|x250px|1975V, lines show 99.7%, 99% and 95% of landau summed 0-4000 (51, 72, 114)]] | ||
+ | |[[Image:run_31839_r5sig_ampfitz.png|thumb|x250px|2000V, lines show 99.7%, 99% and 95% of landau summed 0-4000 (68, 95, 148)]] | ||
+ | |} | ||
+ | |||
+ | |||
+ | {| border="0" cellpadding="2" | ||
+ | |+ 60/40 gas, prototype horizontal, 4sigma (gray) and 5sigma (blue) hit threshold, fit range 5sigma+ | ||
+ | |[[Image:run_31842_ampfitz.png|thumb|x250px|1975V, lines show 99.7%, 99% and 95% of landau summed 0-4000 (62, 83, 126)]] | ||
+ | |} | ||
+ | |||
+ | |||
+ | {| border="1px" cellpadding="2" style="border-style:solid;" | ||
+ | |+ 60/40 gas, noise std dev 16.5, hit threshold 5x16.5 = 82.5, fit range 5pedestalsigma+ | ||
+ | |- | ||
+ | ! HV | ||
+ | ! Fit MPV | ||
+ | ! Fit sigma (FWHM/4) | ||
+ | ! Fit 4sigma/MPV | ||
+ | ! MPV/sigma | ||
+ | ! 4045/MPV | ||
+ | ! 99% point | ||
+ | ! 97% point | ||
+ | ! 95% point | ||
+ | |- | ||
+ | | 1950 | ||
+ | | 180 | ||
+ | | 51 | ||
+ | | 1.14 | ||
+ | | 3.5 | ||
+ | |22 | ||
+ | |72 | ||
+ | |style="background:#CFF" |91 | ||
+ | |103 | ||
+ | |- | ||
+ | | 1975 | ||
+ | | 219 | ||
+ | | 70 | ||
+ | | 1.28 | ||
+ | | 3.1 | ||
+ | |18 | ||
+ | |style="background:#CFF" |72 | ||
+ | |98 | ||
+ | |114 | ||
+ | |- | ||
+ | | 2000 | ||
+ | | 282 | ||
+ | | 89 | ||
+ | | 1.26 | ||
+ | | 3.2 | ||
+ | |14 | ||
+ | |style="background:#CFF" |94 | ||
+ | |128 | ||
+ | |148 | ||
+ | |} | ||
+ | |||
+ | {| border="1px" cellpadding="2" style="border-style:solid;" | ||
+ | |+ same again, ran for longer | ||
+ | ! HV | ||
+ | ! Fit MPV | ||
+ | ! Fit sigma (FWHM/4) | ||
+ | ! MPV/sigma | ||
+ | ! 99% point | ||
+ | ! 4045/MPV | ||
+ | |- | ||
+ | | 1975 | ||
+ | | 233 | ||
+ | | 71 | ||
+ | | 3.3 | ||
+ | | 83 | ||
+ | | 17 | ||
+ | |} | ||
+ | |||
+ | |||
+ | <h4>Fit drift time histogram</h4> | ||
{| border="0" cellpadding="2" | {| border="0" cellpadding="2" | ||
Line 89: | Line 167: | ||
]] | ]] | ||
|} | |} | ||
+ | |||
+ | <h4>Tracking efficiency plot</h4> | ||
+ | |||
+ | {| border="0" cellpadding="2" | ||
+ | |+ Tracks/Triggers, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(5sig)-17 | ||
+ | |[[Image:eff_hv_6040_Aug2012_tf88_tfix1000_np17.png|thumb|x250px| tzero=88ns, early hits ignored | ||
+ | ]] | ||
+ | |} | ||
+ | |||
+ | |||
+ | <h4>Look at position resolution, find best gas mix for Garfield x-t tables</h4> | ||
{| border="0" cellpadding="2" | {| border="0" cellpadding="2" | ||
|+ Resolution for 1975V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(t4sig)-13, tz_add=6, 60/40 Garfield | |+ Resolution for 1975V, hit thresholds 5sigma, timing thresholds 4sigma, 1sigma, pedestal at t(t4sig)-13, tz_add=6, 60/40 Garfield | ||
+ | (ignore the title saying 50/50, I forgot to change that part of the root script) | ||
|[[Image:run_31842_res20_tz6_6040.png|thumb|x250px|1975V, resolution ch 20]] | |[[Image:run_31842_res20_tz6_6040.png|thumb|x250px|1975V, resolution ch 20]] | ||
|[[Image:run_31842_resx20_tz6_6040.png|thumb|x250px|1975V, resolution vs hit radius]] | |[[Image:run_31842_resx20_tz6_6040.png|thumb|x250px|1975V, resolution vs hit radius]] | ||
Line 120: | Line 210: | ||
{| border="0" cellpadding="2" | {| border="0" cellpadding="2" | ||
|+ Resolution for 1975V, drift time > 240ns (~approx 5mm), different gas mix in Garfield, same thresholds and pedestal as before, tz_add=6ns | |+ 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|1975V, resolution | + | |[[Image:run_31842_res20_5mm_6040_tz6.png|thumb|x250px|60/40]] |
− | |[[Image: | + | |[[Image:run_31842_res20_5mm_5941_tz6.png|thumb|x250px|59/41]] |
− | |[[Image: | + | |[[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]] | ||
+ | |} | ||
+ | |||
+ | {| 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]] | ||
+ | |} | ||
+ | |||
+ | <h4>Find what to use for local pedestal</h4> | ||
+ | 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" | ||
+ | |+ 1975V 59/41 Garfield etc Change in ADC value vs time relative to the threshold crossing time (in units of 8ns/5) | ||
+ | |[[Image:run_31842_thr5_findpedpt.png|thumb|x250px|1975V, hit thr 5 ped-sigma]] | ||
+ | |[[Image:run_31842_thr6_findpedpt.png|thumb|x250px|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 | ||
+ | |||
+ | {| border="0" cellpadding="2" | ||
+ | |+ 1975V 58.5/41.5 Garfield etc Resolution for different local pedestal points, tz_add=6ns | ||
+ | |[[Image:run_31824_tz6_npmulti.png|thumb|x250px|10, 15, and 20 points (1.6ns each) before hit threshold]] | ||
+ | |[[Image:run_31824_tz6_npmulti3.png|thumb|x250px|15, 16, and 17 points (1.6ns each) before hit threshold]] | ||
+ | |} | ||
+ | |||
+ | |||
+ | {| border="0" cellpadding="2" | ||
+ | |+ 1975V 58.5/41.5 Garfield etc Resolution for different local pedestal points, tz_add=7ns | ||
+ | |[[Image:run_31824_tz7_npmulti.png|thumb|x250px|10, 15, and 20 points (1.6ns each) before hit threshold]] | ||
+ | |[[Image:run_31824_tz7_npmulti3.png|thumb|x250px|15, 16, and 17 points (1.6ns each) before hit threshold]] | ||
+ | |} | ||
+ | |||
+ | |||
+ | {| border="0" cellpadding="2" | ||
+ | |+ 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 | ||
+ | |[[Image:run_31842_585_415_thr5_np16_tz7_tfix1000_res20.png|thumb|x250px|1975V, resolution ch 20]] | ||
+ | |[[Image:run_31842_585_415_thr5_np16_tz7_tfix1000_resx20.png|thumb|x250px|1975V, resolution vs hit radius]] | ||
+ | |} | ||
+ | |||
+ | <h4>Reassign early hits</h4> | ||
+ | Now include previously ignored hits which arrived before tzero+tz_add, assign these to a fixed drift time | ||
+ | {| border="0" cellpadding="2" | ||
+ | |+ 1975V 58.5/41.5 Garfield etc Resolution for np=16, tz_add=7ns, early hits assigned to 0ns, 1ns, 2ns | ||
+ | |[[Image:run_31824_tz7_tfixmulti.png|thumb|x250px|tfix = 0, 1, 2ns]] | ||
+ | |} | ||
+ | |||
+ | |||
+ | {| border="0" cellpadding="2" | ||
+ | |+ 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 | ||
+ | |[[Image:run_31842_585_415_thr5_np16_tz7_tfix1_res20.png|thumb|x250px|1975V, resolution ch 20]] | ||
+ | |[[Image:run_31842_585_415_thr5_np16_tz7_tfix1_resx20.png|thumb|x250px|1975V, resolution vs hit radius]] | ||
|} | |} | ||
{| border="0" cellpadding="2" | {| border="0" cellpadding="2" | ||
− | |+ Resolution for 1975V, | + | |+ 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 |
− | |[[Image: | + | |[[Image:run_31842_585_415_thr5_np16_tz7_tfix2_res20.png|thumb|x250px|1975V, resolution ch 20]] |
− | |[[Image: | + | |[[Image:run_31842_585_415_thr5_np16_tz7_tfix2_resx20.png|thumb|x250px|1975V, resolution vs hit radius]] |
|} | |} |
Latest revision as of 11:42, 12 February 2013
60/40 Ar/CO2 and cosmics, prototype horizontal
Contents
- 1 Short runs for range of HV, check pedestal is ok and find MPV
- 2 Fit max amplitude histograms and find optimal HV
- 3 Fit drift time histogram
- 4 Tracking efficiency plot
- 5 Look at position resolution, find best gas mix for Garfield x-t tables
- 6 Find what to use for local pedestal
- 7 Reassign early hits
Short runs for range of HV, check pedestal is ok and find MPV
Fit max amplitude histograms and find optimal HV
HV | Fit MPV | Fit sigma (FWHM/4) | MPV/sigma | 99% point | 4045/MPV |
---|---|---|---|---|---|
1950 | 185 | 50 | 3.7 | 79 | 22 |
1975 | 226 | 67 | 3.4 | 84 | 18 |
2000 | 285 | 87 | 3.3 | 101 | 14 |
HV | Fit MPV | Fit sigma (FWHM/4) | Fit 4sigma/MPV | MPV/sigma | 4045/MPV | 99% point | 97% point | 95% point |
---|---|---|---|---|---|---|---|---|
1950 | 180 | 51 | 1.14 | 3.5 | 22 | 72 | 91 | 103 |
1975 | 219 | 70 | 1.28 | 3.1 | 18 | 72 | 98 | 114 |
2000 | 282 | 89 | 1.26 | 3.2 | 14 | 94 | 128 | 148 |
HV | Fit MPV | Fit sigma (FWHM/4) | MPV/sigma | 99% point | 4045/MPV |
---|---|---|---|---|---|
1975 | 233 | 71 | 3.3 | 83 | 17 |
Fit drift time histogram
Tracking efficiency plot
Look at position resolution, find best gas mix for Garfield x-t tables
This does not look nearly as good as 50/50 gas mix. Resolution is calculated as fitted drift distance - measured (interpolated) distance, so it is positive when the measured drift time and distance are too small. 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.
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.
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.
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.
It's easiest to look at resolution far from the wire to find the best gas mix model.
Find what to use for local pedestal
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.
Mean goes through 0.5 and 1 at -16.4 and -13.7 for thr=5sigma, -17.6 and -14.9 for thr=6sigma
Reassign early hits
Now include previously ignored hits which arrived before tzero+tz_add, assign these to a fixed drift time