1. Testbeam analysis on module #1
Lightyield calibration
2. Absorber studies
19/01/06
HCAL main meeting - Marius Groll

2. History of module #1 and setup features
First produced module: suffered under debugging
SiPMs: # MW quenching resistor bias voltage: V
~ 60 long discharge candidates (30 with low frequency)
Light coupling: prototype, no „reflector caps“
Use final VFE electronics (better protected DAC settings)  no unforced losses of DAC values (single user mode)
No electronic temperature measurement
No CMB: only stand-alone LED wo PIN readout
19/01/06
HCAL main meeting - Marius Groll

3. DESY test beam: 1st module test
e-/e+ beam: 1-6 GeV
VME crate
very FE electronics
beam trigger
~150 ns
HCAL
Module 1
NIM trigger logic
19/01/06
HCAL main meeting - Marius Groll

4. Calibration procedure
SiPM Gain calibration
with low intensity LED light
MIP calibration of each tile
with 3 GeV e- beam
0 pixel
1 pixel
2 pixels
Noise spectrum
Minimum ionizing
energy
gain / noise ~ 4
using ASIC chip in 2 modes:
“calibration mode” “physics mode”
short shaping time (40ns) longest shaping time (180 ns)
highest gain medium gain
19/01/06
HCAL main meeting - Marius Groll

5. Uncertainty estimation
Pedestal shift: mean value stable s = 5 ch (MIP ~ 250 ch)  no pedestal correction during data taking  use as systematic error
Temperature corrections: big LED fluctuations: 25% NO Pin correction possible!  analog temperature measurement available: temperature in hall 2: °C  1°C = 3 s error on the meas. SiPM amplitude: 7% / 1 °C  2.5% temperature variation uncertainty
Pedestal change in one week
176
19/01/06
HCAL main meeting - Marius Groll

6. LY calibration on module #1
197 ch.
MIP average:
410 ADC ch +/- 18%
Gain calibration MIP calibration Intercalibration
Beam (sept. 05)
LY: 13 pix/MIP, RMS 2 pix/MIP
Tile tester (dec. 04) LY: 15 pix/MIP, RMS 2 pix/MIP Error on LY: 13.0 ± 0.3 ± 0.7 pix/MIP stat. syst.  D 1 pix/MIP due to temp.
19/01/06
HCAL main meeting - Marius Groll

7. HCAL main meeting - Marius Groll
Bug report
Reasons for failed calibration:
MIP fit failed: 19 channels
Gain fit failed: 11 channels
(Intercalibration failed: 16 channels  use Chip mean) in total: for 25 channels no LY calibration possible (out of which 5 dead channels)
19/01/06
HCAL main meeting - Marius Groll

8. Absorber studies on module #1
HCAL module
5x5 cm scintillator
1 X0 lead
3x3 cm scintillator
with Hammatsu R5505
e+ 1-6 GeV
Lead: RM = 0.9 cm X0 = 0.56 cm
PMT1
PMT2
PMT3
Peter Smirnov and Yuri Soloviev
Data has been taken in one week at the end of september
Energy scan (e+ 2-6 GeV)
PMT calibration wo absorber
1X0 shower data collected with 3 GeV beam  many entries at 1-3 MIPS  better determination of the lower part of the SiPM response function
5X0 shower data collected with 5 GeV beam  high amplitude (~30 MIPS)  SiPM non-linearity correction
19/01/06
HCAL main meeting - Marius Groll

9. HCAL main meeting - Marius Groll
MIP calibration and MC
MIP calibration of PMTs
Pedestal stable at the 1% level
SiPM MIP calibration taken from runs before and after
MC: standalone Geant3 with beam smearing: s beam = 1.5mm
data
before module PMT2
MC: s/mean = 0.08
Data: s/mean = 0.16
 Good PMT resolution
data
after module PMT3 MC
before module
19/01/06
HCAL main meeting - Marius Groll

10. HCAL main meeting - Marius Groll
PMT calibration and MC
Leakage check with 5 X0 & MC comparison
PMT2 & PMT3: non-linear behaviour at 5-6 GeV  ok
Possible explanation:
PMT2: leakage to the side (3x3cm2); checked with bigger 9x9cm2 scintillator
SiPM data correction will follow!
19/01/06
HCAL main meeting - Marius Groll

11. Monte Carlo understanding
MC work done by Y. Soloviev
Geant 3 code
Nice agreement in the PMTs  MC ok
Disagreement for our module if no corrections are applied  non-linearity…
Be aware! Shower fluctuation does not decrease with statistics.
Approx. 30% energy spread
19/01/06
HCAL main meeting - Marius Groll

12. HCAL main meeting - Marius Groll
1X0 analysis
MC:
PMT2: 5.9 MIPs
SiPM: 6.5 MIPs
SSIPM: 7.4 MIPS
PMT3: 4.8 MIPs
Data: chip 5 chan 13
PMT2: 6.2 MIPs
SiPM: 6.8 MIPs
SSIPM: 7.8 MIPs
PMT3: 5.0 MIPs
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HCAL main meeting - Marius Groll

13. HCAL main meeting - Marius Groll
1X0 analysis
But of course you have to do something before:
½ MIP cut  cut away SiPM noise
Non-linearity correction
Light xtalk correction  2.5% in agreement with ITEP meas.
Long discharge handling
PMT2
SIPM
SSiPM
PMT3 MC
5.9
6.5
7.4
4.8
>½ MIP cut
6.2
6.3
7.9
5.0
Linearity correction
6.8
8.5
Light xtalk correction
7.8
Long discharge w or w/o 2% difference in SSiPM
 For events it seems to be not important
19/01/06
HCAL main meeting - Marius Groll

14. HCAL main meeting - Marius Groll
PMT2: plot explanation
The following plots are done by dividing the data/MC into subsamples, which are determined by the numbers of MIP the PMT2 has seen
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HCAL main meeting - Marius Groll

15. 1X0 analysis: data MC comparison
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HCAL main meeting - Marius Groll

16. 1X0 analysis: data MC comparison
SiPM central: wo linearity correction
SiPM neighbours: wo xtalk correction
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HCAL main meeting - Marius Groll

17. HCAL main meeting - Marius Groll
Summary: 1X0 analysis
For 25 3x3 cm tiles:
General agreement to MC only 5% spread between channels w/o any temperature & pedestals corrections
Some physics: determination of lead moliere radius data: RM = 0.76 ± 0.07 cm MC: RM = 0.92 cm
MC prediction
19/01/06
HCAL main meeting - Marius Groll

18. SiPM non-linearity correction
Vassilly Morgunov correction proposal:
comparison to Hendriks measurement in lab.
correction maintained by LED measurements is too small; even after SiPM x-talk correction  open question
19/01/06
HCAL main meeting - Marius Groll

19. HCAL main meeting - Marius Groll
5 GeV analysis
Electromagnetic
shower maximum
MC:
PMT2: 30.3 MIPs
SiPM: 25.9 MIPs
SSIPM: 37.4 MIPS
PMT3: 11.4 MIPs
wo correction
Data: chip 5 chan 9
PMT2: 30.0 MIPs
SiPM: 20.7 MIPs
SiPM_corrected: 26.2 MIPs
SSiPM: 36.4 MIPs
SSiPM_corrected: 39.9 MIPs
PMT3: 10.9 MIPs
w correction
19/01/06
HCAL main meeting - Marius Groll

20. HCAL main meeting - Marius Groll
5 GeV analysis
Central tile/SiPM uncorrected
Central tile/SiPM corrected
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HCAL main meeting - Marius Groll

21. HCAL main meeting - Marius Groll
5X0 analysis
PMT2
SIPM
SSiPM
PMT3 MC
30.3
25.9
37.4
11.4
>½ MIP cut
30.0
20.7
36.4
10.9
Linearity correction
26.2
42.5
Light xtalk correction
39.9
19/01/06
HCAL main meeting - Marius Groll

22. HCAL main meeting - Marius Groll
MiniCal comparison
SIPM
SSiPM
MiniCal 1X0 steal 3 GeV
7.4
8.1
Module 1 1X0 lead 3 GeV
6.8
7.8
MiniCal 5X0 steal 5 GeV
28.0
31.0
Module 1 5X0 lead 5 GeV
26.2
39.9
not completly possible to compare due to the different geometry: MiniCal: 5x5 cm tiles Module 1: 3x3 cm tiles  missing energy in MiniCal due to lateral leakage at the shower maximum  MC crosscheck is needed
19/01/06
HCAL main meeting - Marius Groll

23. HCAL main meeting - Marius Groll
Summary
We have collected first beam data with our detector!
We have learned a lot how to operate it and to collect data with the DAQ BUT: Next time minimisation of blind data taking time
The importance of a good monitoring system is tremendous!
Alternating data taking: data – led monitoring – pedestal is mandatory!
Better knowledge of SiPM saturation curve with our electronics is needed
Data correction procedure for SiPM non-linearity has to be improved
19/01/06
HCAL main meeting - Marius Groll

24. HCAL main meeting - Marius Groll
Backup
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HCAL main meeting - Marius Groll

25. HCAL main meeting - Marius Groll
error bars = error on mean
error bars = RMS
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HCAL main meeting - Marius Groll

26. HCAL main meeting - Marius Groll
5X0 analysis
Analysis needs input for the correct SiPM response function correction
MiniCal correction is doing for the first approximation a good job
wo correction
w correction
19/01/06
HCAL main meeting - Marius Groll

27. HCAL main meeting - Marius Groll
1X0 vs. noise
black: shower
red: noise
1X0 data have in the neighbouring
tiles hit amplitudes comparable to
noise hits
19/01/06
HCAL main meeting - Marius Groll