Status of the Cerenkov detector calibrations and
efficiency analysis
Status of the Cerenkov detector calibrations
and efficiency analysis.
To do :
Calibrations
Amplitude calibrations.
Pedestal calibrations.
Partially done. Needed to get more
calibrations (once per one - two weeks or so)
One photoelectron calibrations CC_CALIB Partially done. Needed to get more
calibrations (once per one - two weeks or so)
Nphe estimate using the dependence of the mean amplitude and
its dispersion in the PMT.
In progress. Have a problem there.
Needs to pay some more attention.
Time calibrations
T1 calibrations
In progress. One calibration
file was written, but... it seems that it is not good.
Attempt to analyze it shows only zeros. Most probably
we'll need more TDC_calib runs made, and need to analyze them.
The problem is that the hardware is NEW, and we CAN NOT use
old values for T1.
T0 calibrations
In progress. At least the program
is ready, one attempt was made to analyze data and find constants.
The problem is with RF time, which is totally wrong.
Need to made TOF calibrations first.
Efficiency
The NEW "CC plane" calculation, comparing to the OLD one.
Done.
The PMT positions are close, so we can use either
"CC plane", The estimated difference is ~1 degree in Theta and
no difference in Phy.
fiducial cuts
Compare the Theta_p - Phy_p plots for the number of
photoelectrons and efficiency for
different initial energies / magnetic fields.
1.3 GeV and 3.0 GeV plots for the number of
photoelectrons compared. No difference seen, what
makes possible to apply the same cut for any energy.
Electron selection for events without CC in the trigger.
In progress. 1.3 data analysis started.
First results shows that the Sector 6 efficiency
in the physical region at Theta_p up
to 35 degrees is rather good, - not less than 98%
Need more statistics and some more cuts for electron selection.
Pion to electron rejection estimate.
In progress (very beginning).
Estimated number of particles in sector 6
with EC_ONLY trigger in the sample of
about 2.5*10^8 events:
pi plus : 4500
pi minus : 250
protons : 1000