Detector tuning / checking

The goal is to check that the detector is working, that the counting rates are normal and that the Møller peaks are located at about ADC channel 300 for all the LG blocks.

A.

Data taking with CODA

1.

Take a RUN for about 20k events. Let us assume the run number is 9911.

A.

Data analysis with PAW

1.

$adaqs3\%PAW>$ exec run run=9911: build an NTUPLE and attach it to the $PAW$ session.

2.

$adaqs3\%PAW>$ exec lg_spectra icut=60 run=9911: look at the ADC distributions. The peaks should be at about ADC channel 300 for all 8 modules. If the peaks are off - try to adjust the HV (do not go beyond 1990V).

B.

Check of the background

1.

Raise the thresholds to 130 mV of the channels 1 and 2 of the discriminator, using the ``mollerSettings'' window.

2.

Take a run of about 20k events, say run=9915

3.

$adaqs3\%PAW>$ exec lg_spectra icut=60 cut=11 run=9915: look at the ADC distributions. The peaks should be at about ADC channel 300 for all 8 modules. The histograms 9 and 10 present the sums of the left and right arms. The histogram 11 (sum of both arms) should contain a clean peak at about channel 600.

4.

$adaqs3\%PAW>$ exec asymp run=9915: polarization analysis should provide a reasonable number. Check the scaler rates per second. The counting rates in each arm should not exceed 600kHz. If they are higher ask the MCC to reduce the beam current.