This page describes the failure of the HE channels of a single GCFE. There are 3072 GCFEs in CAL, two for each of the 1536 xtals.
Symptoms of the failure
On 27 Jul 2010 (Day 208), at 1:55 PM EDT, Anders Borgland wrote:
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For example, for our current failure, we have bad HEX8 and HEX1 data, but we've done nothing to the config registers of this GCFE to prevent HEX8 and HEX1 from appearing. We could configure to prevent them from being selected as the best (i.e. only) range, and we're building that config now as a contingency. The code to detect whether a given event is suffering from the failure will depend on how we've configured the GCFE, and I'm convinced for this particular failure it's better if we don't touch the config. I'd prefer to read the config information out of MOOT for the appropriate run, but I'll bet for the moment we should just merge the h/w status and config into a calibration DB file. That's fine. We won't be changing the relevant configuration parameters on a run-by-run basis, so it'll change slowly if at all, consistent with our usage of calib DB quantities.
— Usage —
Tracy and Chul have started coding following the thoughts laid out below.
Recall that the current recon sequence has two CAL passes, Cal1 and Cal2, surrounding an intervening TKR pass that is TkrReconAlg/FirstPass. We will modify the second CAL pass to include a CalXtalRecAlg member function that fixes the response of each CAL xtal that has a failure. Thus:
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Cal1.Members = {"CalXtalRecAlg/first",
"CalClustersAlg/first",
"CalEventEnergyAlg/RawEnergy"};
Cal2.Members = {"CalXtalRecAlg/FixXtalResp",
"CalEventEnergyAlg/second"};
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I'd like to proceed with getting this new calib quantity in the database so we can extract it in recon with CalCalibSvc.
Eric
– bit map for CalXtalRecData status word –
bit | function |
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status of recon calculation
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Chul,
Here I've detailed the actions for FixXtalResp in the cases we currently understand. I've added a new CalXtalRecData status word definition at the bottom of this email adding Bill's corrected-energy bit and a bit to indicate that we've mitigated the failure.
Eric
Algorithms for correcting current and not-unlikely future failures in FixXtalResp
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case == bad plus-face HEX8 && bad plus-face HEX1 && ! plus-face HE autoranging disabled /* this is the case for the current failure and current configuration */ /* if one of the HEX ranges is best range, fix it */ /* if plus-face first range == (HEX8 || HEX1), calculate E using the opposite face and the externally provided longitudinal position clear the bad energy bit set the externally provided longitudinal position bit (maybe set the failure-mitigation energy bit) */ case == bad plus-face HEX8 && bad plus-face HEX1 && plus-face HE autoranging disabled /* this is the case for the current failure, but it requires a configuration we have not used */ /* if LEX1 is best range and saturated, fix it */ /* if plus-face first range == LEX1 && plus-face > 4050 (i.e. saturated), calculate E using the opposite face and the externally provided longitudinal position clear the bad energy bit set the externally provided longitudinal position bit (maybe set the failure-mitigation energy bit) */ case == bad plus-face LEX8 && bad plus-face LEX1 && bad plus-face HEX8 && bad plus-face HEX1 /* this is the case we may get to soon if this GCFE continues to degrade and the LE ranges fail */ /* in all cases, calculate E using the opposite face and the externally provided longitudinal position clear the bad energy bit set the externally provided longitudinal position bit (maybe set the failure-mitigation energy bit) */ |