is aimed to collect special kind
data for ECAL calibration.
Please, read the instruction to setup
the pi0 Calibration Run .
The second level processes will concentrate on the pi0 candidates and
will fill ntuples with the invariant mass of candidates. At the same time,
the automatic process will gather ntuples and provide control histograms.
The shift crew must
check that pi0 data
is collected in proper way.
Main step of pi0 calibration run
The HERA-B target interaction rate should be set to 5MHz.
Please, check the Bunch Structure distribution on the target display.
No one bunch should be extremely high and the structure of bunches should be clear.
Setup the run of type ECAL pi0 Calibration:
Consult the DAQ settings for run setup parameters.
If by some reason you could not find it there or have a problem, check the
DAQ page,
if it doesn't help contact
ECAL
or
DAQ expert
In the trigger rate window (consult with
DAQ settings ) set
12000 . Don't forget to press
return after input.
See whether everything is OK in all control windows
Check that data are collected and make sense with procedure described
below .
If everything is working properly, you should just wait until the necessary
data sample is collected. We need at least
20 million events ,
(it takes about 1. hour running at 6kHz DAQ rate).
You can find the number of events on the Run Control Panel.
Take care of possible DAQ crashes during the run.
Please write to the shift log-book the numbers of runs and you comments
for every pi0 run
Monitor of pi0 data taking:
During pi0 calibration the online control histograms are provided to shift
crew to control the procedure. Please, used standard Data Quality tools
to display them (DQdisplay). Pi0 control histograms should be found there
among others.
There are 9 pi0 histograms. The names are self-explaining.
Please, pay special attention to the following histograms :
"ClusterX vs ClusterY" - position of clusters used
for analysis. The distribution should be smooth from the center to the edges.
On the border of INNER-MIDDLE parts you can see increase of the occupancy.
Also the channels with no readout are seen. Important that there is
no channel
which is too high with respect to the neighbours.
"Invariant mass", "Background" -
histograms present invariant mass of clusters from the same and mixed events.
You should see a signal in the first and no signal in the second histogram.
The signal looks quite broad and it sits on high background,
however there must be a difference between 2 histograms in the region of
.135 GeV/c^2.
"Cluster energy" -
2 histograms present a energy spectra of the clusters used for analysis.
They must be smooth with clear decrease and
no extra peaks.
No pi0???Trouble shooting section
Check the DAQ is alive and working
Does Data Quality gatherer work properly?
Control histograms should be displayed and updated.
If it is a problem contact DQ expert.
Check if you're really running the run of type
calibration
Is ECAL included into the run?
Is BX structure on the target monitor is
clear? The HERA-B Interaction Rate should be 5-20 MHz.
Try to contact the ECAL expert (48-53, 48-65 or scall). If you didn't succeed, please,
send mail to Olya Igonkina and continue
with
Short Term Plan.
What to do if I don't understand the instructions on
this page
If you feel it could adversely affect the quality of the data being taken,
contact the on-call expert. In any case, send an e-mail to the responsible
for this page.