1. Test Beam Measurements october – november, 2016
D. Hohov1,2, A. Lounis1,2 , C. Nellist1, T. Rashid1,2
1. Laboratoire de L'accélérateur Linéaire
Université Paris-SUD XI
ATLAS Group meeting

2. Test Beam Measurements
Outline
The samples
Clean room characterization and tunings
Test Beam setup
Reconstruction results
Conclusions
Test Beam Measurements

3. Test Beam Measurements
The samples (DUTs)
Testbeam studies are carried out to characterise a novel sensor or read-out chip, the so-called device under test (DUT).
Time over Threshold
For the tests we had two FE-I4 modules:
Module name
Details
Bias voltage
Threshold 7
DUT 0
NP A
150um
80 V
50 V
1600 e
10 ke
DUT 1
NP A
100um
7 ke
Test Beam Measurements

4. Clean room characterization
Analog scan
Digital scan
DUT 1
DUT 2
DUT 1
DUT 2
Test Beam Measurements

5. Clean room characterization
Threshold tunings :
1600 e for both
Tuning
100 um: 7 Tot at 7000 e
150 um: 7 Tot at e
TOT tunings :
Threshold and Noise scans
DUT 0 (150 um)
DUT 1 (100 um)
Test Beam Measurements

6. Test Beam Measurements
Test Beam Setup
Test beam allows the pixel modules to be tested in an environment similar to that which they will be exposed to within the ATLAS detector to determine how well they function.
H6A
Test Beam Measurements

7. Test Beam Measurements
Test Beam Setup
The sensitive elements of the telescope planes are Mimosa26 active pixel sensors with a pixel pitch of 18.4 µm. Each plane consists of x 576 pixels covering an active area of 21.2 x 10.6 mm2
Trigger Logic Unit provides trigger logic and time stamp information on particle passage
Test Beam Measurements

8. Test Beam Measurements
Test Beam Setup
- Readout with RCE system.
Pixel interface
Test Beam Measurements

9. Test Beam Measurements
Data Reconstruction
The raw data has to be reconstructed into the tracks for further analysis
EUTelescope software is developed hand in hand with the AIDA pixel telescope and its DAQ framework EUDAQ
There are five steps for the reconstruction:
Data conversion
data is converted from its raw data format into an LCIO (Linear Collider I/O) raw data collection as well as noisy pixels being determined
Cluster finding
This step is followed by grouping together hit pixels to clusters. These clusters can then be masked and removed if noisy pixels are present in them.
Test Beam Measurements

10. Test Beam Measurements
Data Reconstruction
Hit derivation
The cluster coordinates are initially given only in the local sensor frame in terms of column and row numbers. The transformation from the local (sensor) frame into the global (telescope) frame is done via the telescope description stored in the geometry steering files.
From cluster objects actual hit positions can be derived. As in this step hit positions are available, it is possible to use correlation of such hits on different sensors to obtain a prealignment.
Alignment
In the alignment step, the prealignment together with the derived hits are used to align the setup with an external alignment tools
Pattern recognition and track fitting
In the final step, track finding and fitting, the pre and final alignment are applied to the hits and tracks are derived from these hits.
Test Beam Measurements

11. Test Beam Measurements
Test Beam Results
1) Lvl 1 plots (The Lvl1 plots for (left) DUT 0, (right) DUT 1 at 80V. )
The LVL1 distribution shows the arrival time of every recorded hit with respect to the external trigger signal (14 time windows of 25 ns).
2) Cluster size
Test Beam Measurements

12. Test Beam Measurements
Test Beam Results
3) Correlations
For the telescope planes
For DUTs planes
Test Beam Measurements

13. Test Beam Measurements
Test Beam Results
4) Residuals
5) Hitmaps
Test Beam Measurements

14. Summary and Conclusions
Two samples have been measured at test beam. One of them has incomplete statistics.
Further work on the reconstruction is required.
After reconstruction of all runs, the output ROOT files produced during track reconstruction, analyse with Tbmon (TBmon is a small analysis framework used to study data taken with silicon pixel sensors in a test beam ).
Measurements at the next test beam to complete characterization.
Thank you for your attention!
Test Beam Measurements