Difference between revisions of "CDC 216 channels"
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{| border="0" cellpadding="2" | {| border="0" cellpadding="2" | ||
|[[Image:cdc_run_32563_diptimes_start_90.png|thumb|x250px|Dip times]] | |[[Image:cdc_run_32563_diptimes_start_90.png|thumb|x250px|Dip times]] | ||
− | |[[Image:cdc_run_32563_ringers.png|thumb|x250px|Run | + | |[[Image:cdc_run_32563_ringers.png|thumb|x250px|Run 32563 channels with oscillations]] |
|[[Image:cdc_run_32563_ox_5.png|thumb|x250px|Channel with "hit" <5 samples before oscillation in another channel]] | |[[Image:cdc_run_32563_ox_5.png|thumb|x250px|Channel with "hit" <5 samples before oscillation in another channel]] | ||
+ | |} | ||
+ | |||
+ | Increased scintillator HV to 2100V | ||
+ | {| border="0" cellpadding="2" | ||
+ | |[[Image:cdc_run_32570_diptimes_start_90.png|thumb|x250px|Dip times]] | ||
+ | |[[Image:cdc_run_32570_ringers.png|thumb|x250px|Run 32570 channels with oscillations]] | ||
+ | |[[Image:cdc_run_32570_ox_5.png|thumb|x250px|Channel with "hit" <5 samples before oscillation in another channel]] | ||
|} | |} |
Revision as of 13:36, 14 October 2013
Switched HVBs 3 and 5 (all electronics swapped at the chamber)
Event pics
These data (run 32488) were recorded using a filter in the event readout list, so only channels with 6 consecutive samples exceeding a threshold of 116 were recorded, provided that 5 channels had 8 consecutive samples over 124. (pedestal ~ 60, #sigma ~ 16)
Compare resolution with channels 68 (on noisy board E4) and 148 (similar position on different board E14)
Looking to see if zero-crossings are linked to hits in other channels. Zero-crossing time is the sample number when the adc content drops to 0 - pedestal is not subtracted. Pedestals are set to approx 60, with pedestal width ~ 16.
Switched HVBs 3 and 5 (first is at top, increase top to bottom, L to R)
Below: This run started after the CO2 had run out - more Ar reaching boards 1 and 2 (I8, I9, at the top of the chamber) and then 5 (E6)
Below: Switched preamps for HVBs 3 and 5. There is more CO2 in the gas mix. All else unchanged.
Looking for the oscillation start times - searched for 3 consecutive dips below adc value of 20, starting at sample 0. The first dip time is recorded for each channel.
Changed search start time to sample 90.
Previous run, before preamps 3&5 were exchanged
Switched off HV to CDC
Triggered on lower scint singles, switched off HV to upper scint
Triggered on upper scint singles, switched off HV to lower scint
Triggered on scints in coinc, switched preamps 1 and 2
Moved both scints across to the far lab wall
Removed T to scope from scint signal cables, scints still by the far lab wall
Decreased scintillator HV to 1750V
Increased scintillator HV to 2100V