1. Status of the Calibration
Markus Gaug
IFAE
Udine Bootcamp, 19. April 2004
General overview and status
Deeper look into the calibration:
Calibration procedure
Pedestal subtraction
Oscillating signals
Plans for the next two months
Conclusions, propositions for this bootcamp.

3. 1. Current status hardware:
IFAE Pulser box: After successful installation of optical trigger transmission seems to fully work, except when there is high humidity.
Calibration triggers: Fixed trigger to L2 by separate delayed line, no majority trigger any more, no more cosmics in calibration data.
CT1 Pulser box: Left on the telescope, 10cm closer to box, but trigger cable used by AMC video camera.
Blind Pixel: Seems to be repared, but signals much too long, not yet solved.
PIN Diode: Will be installed in May, new optical read-out.

4. Current Status Software:
Data until March 04: Software fully available, stable and documented. Has to be calibrated with F-Factor method.
Data from March-May 04: Software fully available and documented. Has to be calibrated with F-Factor method, calibration colour has to be written in file name.
Data from May 04 onwards: Need to write interaction with digital modules, intensity calibration missing.

5. 2. Deeper look into Software:
Calibration Procedure: Signal extraction and calculation of calibration constants like decided on the Wuerzburg bootcamp.
New: Treatment of Quantum Efficiency: Calculate for each of the three methods a photons flux. Divided by the number of phe´s gives the quantum efficiency, stored in MCalibrationQECam. This class is filled and merged with the calibrations of different colours and a global QE for cascades is derived.
New: Treatment of Bad Pixels: Continuously, an MBadPixelsCam is filled and merged.
Calibration Procedure: Signal extraction and calculation of calibration constants like decided on the Wuerzburg bootcamp.
New: Treatment of Quantum Efficiency: Calculate for each of the three methods a photons flux. Divided by the number of phe´s gives the quantum efficiency, stored in MCalibrationQECam. This class is filled and merged with the calibrations of different colours.
Calibration Procedure: Signal extraction and calculation of calibration constants like decided on the Wuerzburg bootcamp.

6. 2. Calibration Procedure (II.)
Once, Digital Modules installed:
One intensity and QE calibration at the beginning of the night:
MIntensityCam: Conversion factors, High-Low Gain conversion, dep. on intensity
MCalibrationQECam: Quantum efficiencies, merging of different colour calibrations, different methods.
MBadPixelsCam: Select already the bad of the bad ones.
Every 5-10 mintutes calibration with low intensity:
Update conversion factors
Monitor quantum efficiencies
Once, Digital Modules installed:
One intensity and QE calibration at the beginning of the night:
MIntensityCam: Conversion factors, High-Low Gain conversion, dep. on intensity
MCalibrationQECam: Quantum efficiencies, merging of different colour calibrations, different methods.
MBadPixelsCam: Select already the bad of the bad ones.
Every 5-10 mintutes calibration with low intensity:
Update conversion factors
Monitor quantum efficiencies

7. 2. Pedestal subtraction
Now: Calculate pedestal and ped. RMS on the sums of 14 FADC slices (MPedCalcPedRun) and transform:
Mean Pedestal/slice = Mean of sums / number of slices
Pedestal RMS/slice = RMS of sums / sqrt(nr. slices)
Check: Are these relations true?

8. 2. Changing behaviour over time
Sometimes, calibration constants seem to look nice, but:

9. 2. Oscillations
All runs analysed so far, seem to oscillate at low frequency:

10. 3. Plans for the next 2 months
May at La Palma:
Installation of PIN Diode
Installation of the digital modules
Readjustment of calib. Trigger (pre-scaler delay)
Define standard calibration procedure in Arehucas
May/June at Barcelona:
Implementation of MIntensityCam and lecture of DMs
Combination of colour measurements
Update Tdas0204 – full documentation of calibration algorithms

11. 4. Conclusions
For analysis of February and March data, charge and rel. time calibration is fully implemented.
Classes are documented now.
Need systematic check of all the data
In May last major update of in calibration hardware.
Pedestals Oscillate!!!
DAQ reads out the pulses too late (since March)
Need to re-define the way, pedestal RMS are calculated.

12. 5. Propositions for this bootcamp
Decide how to calculate Pedestal RMS.
Define one standard signal extractor.
Put standardized code into classes (examples: MJPedestal, MJCalibration, …)
Define how to monitor the camera stability and calibration constants, already inside one run.
Automatize the way to pick the right pedestal and calibration files.
Connection to Database.
Code test bench