Difference between revisions of "CDC prototype more drift times"
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Drift time histograms for various local pedestal points | Drift time histograms for various local pedestal points | ||
<br> | <br> | ||
| − | The pedestal | + | The local pedestal is taken to be the mean of a number of samples (pedestal window) ending a certain number of samples (pedestal lead time) before the bin where the hit crossing threshold is exceeded. Typically for a hit threshold of 5x pedestal sigma, a window of 1 or 2 samples ending at a lead time of 3 or 4 samples works well. For a window of 1 sample and lead time of 3 samples, the pedestal value is taken to be equal to the fADC value 3 samples before the hit threshold is exceeded. |
Also see [[CDC_prototype_more_on_timing]] | Also see [[CDC_prototype_more_on_timing]] | ||
<br> | <br> | ||
| − | Le_bin is the timing threshold crossing in fADC samples (8ns each) | + | In the histograms below...<br> |
| − | Le_bin=0 corresponds to (15 + | + | The hit threshold is 5sigma and the (lower, earlier) timing threshold is 1sigma above pedestal. <br> |
| − | + | Le_bin is the timing threshold crossing in fADC samples (8ns each), relative to the hit threshold crossing time.<br> | |
| − | + | Le_bin=0 corresponds to (15 + pedestal_lead) samples before the hit threshold crossing bin.<br> | |
| − | + | Le_bin=15 corresponds to pedestal_lead samples before the hit threshold crossing, this is where the pedestal window ends.<br> | |
| + | The 1-sigma threshold time is the bin where the 1-sigma timing threshold is crossed, relative to the trigger time, | ||
| + | ie the hit threshold crossing bin - 15 - pedestal_lead_time + le_bin. | ||
| + | 20 + pedestal_lead_time values are used for upsampling, starting at le_bin=0 and ending 5 samples after the hit threshold crossing bin. | ||
| + | <br><br> | ||
{| border="0" cellpadding="2" | {| border="0" cellpadding="2" | ||
| − | |+Threshold time (8ns samples) and leading edge time at 1-sigma with pedestal 2 bins before 5-sigma | + | |+Threshold time (8ns samples) and leading edge time at 1-sigma with pedestal 2 bins before 5-sigma hit threshold crossing |
|[[Image:run_31761_p2w1_lebin20.png|thumb|x250px|leading edge time ]] | |[[Image:run_31761_p2w1_lebin20.png|thumb|x250px|leading edge time ]] | ||
|[[Image:run_31761_p2w1_thrtime20.png|thumb|x250px|1-sigma threshold time]] | |[[Image:run_31761_p2w1_thrtime20.png|thumb|x250px|1-sigma threshold time]] | ||
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{| border="0" cellpadding="2" | {| border="0" cellpadding="2" | ||
| − | |+Threshold time (8ns samples) and leading edge time at 1-sigma with pedestal 3 bins before 5-sigma | + | |+Threshold time (8ns samples) and leading edge time at 1-sigma with pedestal 3 bins before 5-sigma hit threshold crossing |
|[[Image:run_31761_p3w1_lebin20.png|thumb|x250px|leading edge time ]] | |[[Image:run_31761_p3w1_lebin20.png|thumb|x250px|leading edge time ]] | ||
|[[Image:run_31761_p3w1_thrtime20.png|thumb|x250px|1-sigma threshold time]] | |[[Image:run_31761_p3w1_thrtime20.png|thumb|x250px|1-sigma threshold time]] | ||
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{| border="0" cellpadding="2" | {| border="0" cellpadding="2" | ||
| − | |+Threshold time (8ns samples) and leading edge time at 1-sigma with pedestal 4 bins before 5-sigma | + | |+Threshold time (8ns samples) and leading edge time at 1-sigma with pedestal 4 bins before 5-sigma hit threshold crossing |
|[[Image:run_31761_p4w1_lebin20.png|thumb|x250px|leading edge time ]] | |[[Image:run_31761_p4w1_lebin20.png|thumb|x250px|leading edge time ]] | ||
|[[Image:run_31761_p4w1_thrtime20.png|thumb|x250px|1-sigma threshold time]] | |[[Image:run_31761_p4w1_thrtime20.png|thumb|x250px|1-sigma threshold time]] | ||
| Line 36: | Line 40: | ||
{| border="0" cellpadding="2" | {| border="0" cellpadding="2" | ||
| − | |+Threshold time (8ns samples) and leading edge time at 1-sigma with pedestal 5 bins before 5-sigma | + | |+Threshold time (8ns samples) and leading edge time at 1-sigma with pedestal 5 bins before 5-sigma hit threshold crossing |
|[[Image:run_31761_p5w1_lebin20.png|thumb|x250px|leading edge time ]] | |[[Image:run_31761_p5w1_lebin20.png|thumb|x250px|leading edge time ]] | ||
|[[Image:run_31761_p5w1_thrtime20.png|thumb|x250px|1-sigma threshold time]] | |[[Image:run_31761_p5w1_thrtime20.png|thumb|x250px|1-sigma threshold time]] | ||
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|} | |} | ||
<br> | <br> | ||
| − | <span style=" | + | {| border="0" cellpadding="2" |
| + | |+Threshold time (8ns samples) and leading edge time at 1-sigma with pedestal mean of 3 and 4 bins before 5-sigma hit threshold crossing | ||
| + | |[[Image:run_31761_p3w2_lebin20.png|thumb|x250px|leading edge time ]] | ||
| + | |[[Image:run_31761_p3w2_thrtime20.png|thumb|x250px|1-sigma threshold time]] | ||
| + | |[[Image:run_31761_p3w2_thrtime20z.png|thumb|x250px|1-sigma threshold time]] | ||
| + | |[[Image:run_31761_p3w2_res20.png|thumb|x250px|Ch20 resolution]] | ||
| + | |} | ||
| + | {| border="0" cellpadding="2" | ||
| + | |+As above for untracked data and broader histogram bins (Threshold time (8ns samples) and leading edge time at 1-sigma with pedestal mean of 3 and 4 bins before 5-sigma hit threshold crossing) | ||
| + | |[[Image:run_31761_p3w2_lebin20_untr.png|thumb|x250px|leading edge time ]] | ||
| + | |[[Image:run_31761_p3w2_thrtime20_untr.png|thumb|x250px|1-sigma threshold time]] | ||
| + | |[[Image:run_31761_p3w2_thrtime20_untrz.png|thumb|x250px|1-sigma threshold time]] | ||
| + | |} | ||
| + | <span style="color:#fff">colors:851,836,426,871,606,pink+1</span> | ||
<br> | <br> | ||
| + | {| border="0" cellpadding="2" | ||
| + | |+leading edge time (1-sigma) vs threshold time (5-sigma), pedestal mean of 3&4 bins before hit threshold crossing) | ||
| + | |[[Image:run_31761_lebinxthr20.png|thumb|x250px|leading edge time ]] | ||
| + | |} | ||
| + | |||
| + | {| border="0" cellpadding="2" | ||
| + | |+Leading edge time for selected threshold times (as above) | ||
| + | |[[Image:run_31761_lebinxthr20_200.png|thumb|x250px|leading edge time for threshold time 200 to 204 bins ]] | ||
| + | |[[Image:run_31761_lebinxthr20_220.png|thumb|x250px|leading edge time for threshold time 220 to 229 bins ]] | ||
| + | |[[Image:run_31761_lebinxthr20_250.png|thumb|x250px|leading edge time for threshold time 250 to 259 bins ]] | ||
| + | |} | ||
| + | {| border="0" cellpadding="2" | ||
| + | |+Threshold time for selected leading edge times (as above) | ||
| + | |[[Image:run_31761_thrtime20.png |thumb|x250px|threshold time (all) ]] | ||
| + | |[[Image:run_31761_thrtime20_le15.png |thumb|x250px|threshold time for leading edge time 15 to 15.5 bins ]] | ||
| + | |[[Image:run_31761_thrtime20_le15_5.png |thumb|x250px|threshold time for leading edge time 15.5 to 16 bins ]] | ||
| + | |} | ||
| + | {| border="0" cellpadding="2" | ||
| + | |+Threshold time for selected leading edge times (as above) | ||
| + | |[[Image:run_31761_thrtime20_le16.png |thumb|x250px|threshold time for leading edge time 16 to 16.5 bins ]] | ||
| + | |[[Image:run_31761_thrtime20_le16_5.png |thumb|x250px|threshold time for leading edge time 16.5 to 17 bins ]] | ||
| + | |[[Image:run_31761_thrtime20_le17.png |thumb|x250px|threshold time for leading edge time 17 to 17.5 bins ]] | ||
| + | |||
| + | |} | ||
Latest revision as of 18:52, 9 March 2012
Drift time histograms for various local pedestal points
The local pedestal is taken to be the mean of a number of samples (pedestal window) ending a certain number of samples (pedestal lead time) before the bin where the hit crossing threshold is exceeded. Typically for a hit threshold of 5x pedestal sigma, a window of 1 or 2 samples ending at a lead time of 3 or 4 samples works well. For a window of 1 sample and lead time of 3 samples, the pedestal value is taken to be equal to the fADC value 3 samples before the hit threshold is exceeded.
Also see CDC_prototype_more_on_timing
In the histograms below...
The hit threshold is 5sigma and the (lower, earlier) timing threshold is 1sigma above pedestal.
Le_bin is the timing threshold crossing in fADC samples (8ns each), relative to the hit threshold crossing time.
Le_bin=0 corresponds to (15 + pedestal_lead) samples before the hit threshold crossing bin.
Le_bin=15 corresponds to pedestal_lead samples before the hit threshold crossing, this is where the pedestal window ends.
The 1-sigma threshold time is the bin where the 1-sigma timing threshold is crossed, relative to the trigger time,
ie the hit threshold crossing bin - 15 - pedestal_lead_time + le_bin.
20 + pedestal_lead_time values are used for upsampling, starting at le_bin=0 and ending 5 samples after the hit threshold crossing bin.
colors:851,836,426,871,606,pink+1
