Difference between revisions of "CDC prototype more drift times"
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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 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]] | ||
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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 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> | ||
{| border="0" cellpadding="2" | {| 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 | + | |+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_lebin20.png|thumb|x250px|leading edge time ]] | ||
|[[Image:run_31761_p3w2_thrtime20.png|thumb|x250px|1-sigma threshold time]] | |[[Image:run_31761_p3w2_thrtime20.png|thumb|x250px|1-sigma threshold time]] | ||
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|} | |} | ||
{| border="0" cellpadding="2" | {| 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 | + | |+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_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_untr.png|thumb|x250px|1-sigma threshold time]] | ||
|[[Image:run_31761_p3w2_thrtime20_untrz.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</span> | + | <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 ]] | ||
| + | |} | ||
Revision as of 17:42, 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
