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daq:mode2 [2012/05/18 08:30] weisshaa created |
daq:mode2 [2014/02/27 16:14] (current) |
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| + | ====== DAQ:Mode 2 data loss (Chris) ====== | ||
| + | |||
| ====== Severity ====== | ====== Severity ====== | ||
| + | We cannot afford losing <del>any triggered</del> data //**in an uncounted manner**//. For absolute x-section measurements with GRETINA efficiency is crucial. | ||
| ====== Problem ====== | ====== Problem ====== | ||
| + | For S800-GRETINA data with GRETINA self-trigger only we find S800 events in Global.dat without corresponding GRETINA event. | ||
| + | |||
| + | == Size of problem (from Scott's email)== | ||
| + | |||
| + | In a low rate file, the following event counts were found: | ||
| + | | ||
| + | 11,886 coincident events (s800 and gretina present with correlated timestamp) | ||
| + | 719 s800 only events | ||
| + | 15 gretina only events (now fixed in S800 daq) | ||
| + | |||
| + | So, ~6% of the decomposed data is missing. | ||
| + | | ||
| + | Also, missing gretina data is spread throughout the file, not concentrated at the beginning or end. | ||
| ====== Progress ====== | ====== Progress ====== | ||
| + | * 5/17/2012: Discussed losses with Mario. Code review and version check to follow. | ||
| + | * 5/24/2012: (kathrin) checked runs 694 (old decomp) and 697 (new decomp) taken on 05/22 | ||
| + | |||
| + | coincidences = s800 and gretina GGEB header with time stamps within 1000 ticks | ||
| + | s800 singles = missing gretina GGEB header and event | ||
| + | gretina singles = no s800 in this event | ||
| + | decomp fails = error in decomposition, "pad" of gretina struct is != 0 (I get errors 3 and 5 see below) | ||
| + | |||
| + | Run 694: | ||
| + | 172171 coincidences (94.4 %) | ||
| + | 10207 S800 singles (5.6 %) | ||
| + | 18 Gret singles (0.0 %) | ||
| + | 0 Decomp fails (0.0 %) | ||
| + | |||
| + | Run 697: | ||
| + | 97888 coincidences (91.2 %) | ||
| + | 9477 S800 singles (8.8 %) | ||
| + | 0 Gret singles (0.0 %) | ||
| + | 81 Decomp fails (0.1 %) | ||
| + | | ||
| + | decomp fails are included in the coincidences (since they have a valid time stamp), as error I get 3 and 5. | ||
| + | in both cases the event is completely empty (everything is zero) except for the crystal_id. | ||
| + | out of the 81 failures I have 54 error 3 (no net charge segments) and 27 times error 5 (bad chi^2) | ||
| + | | ||
| + | this test has to be repeated, to me it is completely unclear, why run 694 has again S800 problems (these were thought to be solved before) | ||
