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BOS Testbeam Results in 2001. 1. Drift time spectra 2. RT-relation 3. Resolution - HV & threshold dependance -Comparison with the 1999 data 4. Summary. MPI & LMU, Munich. - PowerPoint PPT Presentation
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BOS BOS Testbeam ResultsTestbeam Results
in 2001 in 2001
BOS BOS Testbeam ResultsTestbeam Results
in 2001 in 2001
MPI & LMU, Munich 1. Drift time spectra 2. RT-relation 3. Resolution -HV & threshold dependance -Comparison with the 1999 data 4. Summary
1. Drift time spectra 2. RT-relation 3. Resolution -HV & threshold dependance -Comparison with the 1999 data 4. Summary
________________________________________________________________________________________
Sandra Horvat 10.12.2000, Testbeam meeting, CERN
Teststand & ProgramChamber: BOS-0Chamber: BOS-0- same chamber type as in the 1999 testbeam, (differrent electronics!)
- runs with 2 or 4 mezzanine cards- flowing nitrogen in ML2, to avoid high HV currents
Threshold scan: 60 mV 77 mV 90 mV 98 mV HV scan: 2980 V 3080 V 3180 VAngular scans (900-1000, 1100-1300) => still to be analised…
ML1
ML2
______________________________________________________________________________________ 1 Sandra Horvat
10.12.2000, Testbeam meeting, CERN
3 sections scanned, 10 cm each
Drift Time Spectra
_____________________________________________________________________________________ 2 Sandra Horvat
10.12.2000, Testbeam meeting, CERN
3080 V 77 mV
60 mV77 mV98 mV
2980 V3080 V3180 V
2001:60 mV threshold,trise=(10.6±0.3) ns
1999:25e threshold,
trise=(8.4±0.4) ns
Fine Time Oscillations
_____________________________________________________________________________________ 3 Sandra Horvat
10.12.2000, Testbeam meeting, CERN
Channel 2 Channel 16
Fine time spectra Fine time spectra
Uncorrected Drift Time
Corrected Drift Time
Uncorrected Drift Time
Corrected Drift Time
trise=11.6 ns trise=12.8 ns
Excluded from the analysis!
Maximum drift time & Rise time
______________________________________________________________________________________ 4 Sandra Horvat
10.12.2000, Testbeam meeting, CERN
t=t0-tmaxtrise=4T0
t decreases with : threshold (due to the change in t0) HV (due to t0 & tmax)- trise degradation at higher threshols and lower HV => implies degradation in the tube resolution
RT-relation1. step: applying the rt-relation from 1999 testbeam (determined by a silicon tracker) and tracking through the 6 layers (using LMU analysis software)
2. step:Autocalibration – correcting the rt-relation using residuals from the track, 15 bins of 1 mm
_____________________________________________________________________________________ 5 Sandra Horvat
10.12.2000, Testbeam meeting, CERN
residuals
r=4.5mm r=10.5 mm
Tube Resolution
Method:- tracking through the 5 layers,- track interpolation to the tube in the excluded layer (excluding layers 1, 3, 4 & 6)-histograming the distance of the real hit from the track, rextrapolated-rmeasured
Measured resolution:meas=(rextrapolated-rmeasured)
Correcting for the fit error-> tube resolution:tube resolution:real= sqrt (2
measured-corr),
Where corr=2(m)*z2+2(b),
track is given by : y=z*m+b
_____________________________________________________________________________________ 6 Sandra Horvat
10.12.2000, Testbeam meeting, CERN
Tube Resolution - Results
_____________________________________________________________________________________ 7 Sandra Horvat
10.12.2000, Testbeam meeting, CERN
-Similar resolution curves obtained for all layers.
- Good reproducibility!
Preliminary! Preliminary!
Tube Resolution – Threshold & HV dependence
_____________________________________________________________________________________ 8 Sandra Horvat
10.12.2000, Testbeam meeting, CERN
Preliminary! Preliminary!
- degradation of the resolution with the rising threshold- resolution improves with higer HV (at lower radii)
Comparison with the 1999 data
_____________________________________________________________________________________ 9 Sandra Horvat
10.12.2000, Testbeam meeting, CERN
Resolution curve for the 1999 testbeam: obtained using the same analysis method as for 2001 testbeam data
This is compared to the single tube resolution,obtained by a silicon tracker => 5-hit tracking method gives similar results as silicon tracker (differences for large radii)
2001 testbeam results show aslight degradation in the resolutionwith respect to the 1999 testbeam(same chamber type and gas as in 1999) Electronis?
Preliminary!
BOS <-> BIL2001 testbeam results
_____________________________________________________________________________________ 10 Sandra Horvat
10.12.2000, Testbeam meeting, CERN
BOS BIL
- BOS resolution curve rises somewhat more slowly- similar resolution at large r
Summary Drift time spectra :Drift time spectra :• low noise• larger rise time compared with 1999.• dependence on threshold & HV• fine time oscillations in some channels
Tube Resolution:Tube Resolution: • calculated by tracking through 5 layers (LMU software)• similar resolution for all layers, reproducible results• dependence on threshold & HV• degradation with respect to the 1999. data (both silicon tracker and tracking through 5 layers give similar result for 1999.)• BOS 2001. comparable to BIL 2001. testbeam results
_____________________________________________________________________________________ 11 Sandra Horvat
10.12.2000, Testbeam meeting,CERN
Many, many special thanks to the Many, many special thanks to the ROME group, for the constant ROME group, for the constant help, support & help, support & encouragement !!!encouragement !!!
Many, many special thanks to the Many, many special thanks to the ROME group, for the constant ROME group, for the constant help, support & help, support & encouragement !!!encouragement !!!
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