Difference between revisions of "PreAmp tests with premixed 90/10 Ar/CO2 - software threshold"
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We started at 1450V for premixed 90/10 Ar/CO2 (as that was the optimum HV determined previously) and varied the software acceptance threshold, then repeated for 1475V and 1425V. | We started at 1450V for premixed 90/10 Ar/CO2 (as that was the optimum HV determined previously) and varied the software acceptance threshold, then repeated for 1475V and 1425V. | ||
− | In the analysis software, events are required to have a minimum amplitude of (pedestal_mean) + (fADCthreshold)*pedestal_sigma. Tracking efficiency is calculated as (number of events containing valid tracks)/(number of cosmic triggers from the scintillators above and below the prototype). | + | In the analysis software, events are required to have a minimum amplitude of (pedestal_mean) + (fADCthreshold)*pedestal_sigma. A typical value of pedestal_sigma is 12 channels. Tracking efficiency is calculated as (number of events containing valid tracks)/(number of cosmic triggers from the scintillators above and below the prototype). |
====1450V==== | ====1450V==== | ||
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|width="400pt"|[[Image:efficiency_with_threshold_1450V.jpg|thumb|none|400px|Tracking efficiency with software threshold, 1450V, 90/10 premix]] | |width="400pt"|[[Image:efficiency_with_threshold_1450V.jpg|thumb|none|400px|Tracking efficiency with software threshold, 1450V, 90/10 premix]] | ||
|} | |} | ||
+ | |||
+ | Untracked (all the others are tracked) max amplitude histogram | ||
+ | {| border="1" cellpadding="2" | ||
+ | |width="400pt"|[[Image:untracked_amp_thr3_1450V.jpg|thumb|none|400px|Untracked max amplitude histogram, 1450V, 90/10 premix]] | ||
+ | |} | ||
+ | |||
Max amplitude histograms for fADCthresholds 3, 4 | Max amplitude histograms for fADCthresholds 3, 4 | ||
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{| border="1" cellpadding="2" | {| border="1" cellpadding="2" | ||
|width="400pt"|[[Image:amp_thr5_1425V.jpg|thumb|none|400px|Max amplitude histogram, software threshold 5, 1425V, 90/10 premix]] | |width="400pt"|[[Image:amp_thr5_1425V.jpg|thumb|none|400px|Max amplitude histogram, software threshold 5, 1425V, 90/10 premix]] | ||
+ | |} | ||
+ | |||
+ | ====Tracking efficiency with HV for different software thresholds==== | ||
+ | {| border="1" cellpadding="2" | ||
+ | |width="400pt"|[[Image:eff_with_hv_and_thr.jpg|thumb|none|400px|Tracking efficiency with HV and software threshold, 90/10 premix]] | ||
|} | |} |
Latest revision as of 10:45, 22 July 2010
We started at 1450V for premixed 90/10 Ar/CO2 (as that was the optimum HV determined previously) and varied the software acceptance threshold, then repeated for 1475V and 1425V.
In the analysis software, events are required to have a minimum amplitude of (pedestal_mean) + (fADCthreshold)*pedestal_sigma. A typical value of pedestal_sigma is 12 channels. Tracking efficiency is calculated as (number of events containing valid tracks)/(number of cosmic triggers from the scintillators above and below the prototype).
1450V
Tracking efficiency as a function of fADCthreshold
Untracked (all the others are tracked) max amplitude histogram
Max amplitude histograms for fADCthresholds 3, 4
Max amplitude histogram for fADCthreshold 2
1475V
Tracking efficiency as a function of fADCthreshold
Max amplitude histograms for fADCthresholds 3, 4
1425V
Tracking efficiency as a function of fADCthreshold
Max amplitude histograms for fADCthresholds 3, 4
Max amplitude histograms for fADCthreshold 5