First Look at the Beam Test Results of the FPIX2 Readout Chip for the Btev Silicon Pixel Detector

1. First Look at the Beam Test Results of the FPIX2 Readout Chip for the Btev Silicon Pixel Detector L. Uplegger, J. A. Appel, M. Artuso, G. Cardoso, H. P. Cease, D. C. Christian, D. A. Cinabro, S. Kwan, S. Magni, D. Menasce, C. Newsom, A. Schreiner, M. A. Turqueti, J. Wang Talk given by Lorenzo Uplegger

2. Test-beam main goals • Measure the spatial resolution of the sensors before and after • irradiation • Test the read-out chip (ROC) close to real BTeV working conditions • Realize a tracking system completely based on pixel detectors • Build events using only the temporal information (timestamp) • associated to pixel cells without the aid of an external trigger

3. Tevatron CDF BTeV at C0 D0 p p BTeV at Fermi National Accelerator Laboratory

4. RICH SM3 Magnet Straws & Si Strips Muon EM Cal BTeV detector layout 30 Pixel Detector Stations

5. BTeV pixel detector

6. FPIX2 Readout chip 22 Columns 128 Rows

7. 120GeV p Test beam setup • 3 FPIX1 pixel detectors upstream and 3 FPIX1 pixel detectors downstream compose the telescope • The FPIX2 detector under test is in the center. • it can be rotated from 0 to 25 degrees • a cooling system can lower the temperature to -5° C Y measuring orientation FPIX1 Y measuring planes at 0 deg X measuring orientation FPIX1 X measuring planes at 10 deg Can rotate from 0 to 25 deg in steps of 5 deg FPIX2 Detector Under Test

8. DATA DATA DATA DATA DATA DATA Data acquisition system PCI BUS 1 mezzanine card distributes the Master clock to all the other cards. All cards distribute then the same clock to all detectors which are therefore synchronous!

9. Data1 Ts 6 Data2 Ts 6 Data3 Ts 6 Data4 Ts 6 Data5 Ts 6 Data6 Ts 6 Data7 Ts 6 Data1 Ts 2 Data1 Ts 2 Data2 Ts 2 Data2 Ts 2 Data3 Ts 2 Data3 Ts 2 Data4 Ts 2 Data4 Ts 2 Data5 Ts 2 Data5 Ts 2 Data6 Ts 2 Data6 Ts 2 Data7 Ts 2 Data7 Ts 2 DAQ main features 2Mhz CLK particles 5 4 3 6 2 timestamp 1

10. XY track distribution on the pixel detectors 7 plane coincidences FPIX1 Telescope FPIX2 Device Under Test

11. Temperature dependence at different angles • Linear charge sharing applied • Threshold set at 1800 e- • The distribution of the • residuals decreases until • 15deg and then increases • again. • The resolution (without • removing telescope resolution) • varies from 12 to 7.5 m • The change in temperature • doesn’t change significantly the • resolution.

12. Sensor bias dependence at different angles • Linear charge sharing is applied • Threshold set at 1800 e- • The resolution (without • removing telescope resolution) • varies from 12 to 7.5 m • The same behavior is observed for three different Voltages applied to the sensor.

13. Cluster size = 1 • Cluster size = 2 • Cluster size ≥ 3 Cluster size as function of angle The angular dependence of the resolution can be easily understood observing the percentage of clusters sizes for different angles. The resolution improves when the number of hits in the cluster is 2 and the charge sharing can be used to determine the position of the hit.

14. Cluster size shapes for different angles Cluster size = 1 Cluster size = 2 Cluster size ≥ 3

15. Conclusions • We showed the first results of the test beam carried out at Fermilab in summer 2004 • We were able to build a system with FPIX1 pixel detectors as telescope and to characterize • the FPIX2 pixel read out chip • We collected data for different FPIX2 detectors and we were able to study the spatial • resolution as a function of the angle, temperature and bias applied to the sensor. • The detector angle causes the main effect on resolution. • The temperature and bias applied don’t affect resolution significantly • Last month we irradiated these FPIX2 detectors in a high intensity proton beam. • They have already been tested on the bench and they are working • We will characterize them again in December when the beam will be available again after the current accelerator shutdown