1. Pion and X-Ray Beam tests of 3D TimePix Detectors
G. Stewart on behalf of Glasgow/CNM/Diamond 3D group
Pion testbeam was conducted by LHCb/Medipix groups, led by Richard Plackett.
X-Ray Testbeam was conducted by C. Parkes, D. Maneuski, A. MacRaighne,
C. Fleta, N. Tartoni, E. Gimenez
See backup slide for full list of participants

2. Outline Introduction 3D double sided detectors substrates
Medipix and Timepix description
X-ray beam
Set up
Charge Sharing
Efficiency maps
Pion-beam from SPS
Set-up
Efficiency and Energy Spectra
Conclusions

3. Detector substrates - 3D and Planar
Detectors are designed at Glasgow and fabricated at Centro Nacional de Microelectronica, Barcelona
Columns are etched from opposite sides of substrate
Column fabrication:
Reactive ion etching
Partial filing with polysilicon then doping
Radiation Hardness Reduced Charge Sharing
25:1
Glasgow group
Made both hole and collecting type devices
P-type electron collecting faster response
Electrons have longer lifetime after irradiatioon
Charge sharing in double-sided 3D Medipix2 detectors
D. Pennicard, et al. ,NIM A, Vol. 604, Issues 1-2, 1 June 2009, Pages

4. Medipix and Timepix Medipix Timepix
Detector substrate
Amplifier
Amplifier
Threshold
Threshold
Discriminator
Discriminator
65k single-photon counting pixel array
Square pixel size of 55µm
Electron or hole collection
Threshold equalisation
Count rate of ~100kHz
Readout in 300µs
High dynamic range
N counts
Pixel Counter
Pixel Counter +1 +N
Readout
Readout

5. 3D Medipix2 (+ 1 planar) bump bonded at VTT
3D Pixel Medipix2 test
3D Medipix2 (+ 1 planar) bump bonded at VTT
USB Interface for Medipix (CTU, Prague)
Tested Diamond Synchrotron 3D
Planar
Powder Diffraction Ring

6. 3D, 15keV Planar, 15keV Spectral scan Noise Signal 23% Charge sharing
Monochromatic beam
Threshold energy scanned through signal into noise
Charge sharing reduced in 3D detector
self shielding geometry
3D, 15keV
Planar, 15keV
Noise
Signal
23%
Charge sharing
40%
Synchrotron Tests of a 3D Medipix2 X-Ray Detector, D. Pennicard et al., IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL. 57, NO. 1, FEBRUARY 2010

7. Pixel Maps Microfocus beam 5µm FWHM 77.5µm square scans (55µm pixel)
2.5µm steps
Background subtracted
Interpolated
Threshold ~ 50% of beam energy
7% drop in both

8. Charge Sharing 42.5µm Line Sections THL level ~50% beam energy
Aqdvantage disadvantage
THL level
~25% beam energy

9. Charge Sharing Double counting at edge More in Planar than 3D
THL~25%
Double counting at edge
More in Planar than 3D
THL~50%
THL~75%
Edge effect extends further into pixel in planar
Normalised counts
Fwhm numbers
Numbers on peaks
Perlim but indicatioln
Reduced level of over counting and under counting in 3D
= Reduced Charge Sharing
Planar
P-Type
N-Type µm µm µm

10. MIP beam from SPS Secondary 120 GeV pion beam from SPS
Medipix & LHCb
Secondary 120 GeV pion beam from SPS
4 Timepix, 2 Medipix planes in telescope
DUT: double sided 3D N-type sensor from CNM/Glasgow
Expected track extrapolation error: < 3 μm
DUT can be rotated to give different angles of incidence.
Normal incidence
Pion beam
Individual pion tracks
telescope
DUT

11. Detector Signal
Charge collection map - average value of landau as a function of position
Summing charge in 3x3 pixel array around intercept point
Averaged result over all pixels
Drop in signal at the electrode positions
Threshold just above noise level

12. Relative Signal Size Normal Incidence, 0°
The charge collection map was normalised based on taking the ring shown to be 100% charge collection.
Normal Incidence, 0°

13. Relative Signal Size
The charge collection map was normalised based on taking the ring shown to be 100% charge collection. 2°

14. Relative Signal Size
The charge collection map was normalised based on taking the ring shown to be 100% charge collection. 4°

15. Relative Signal Size
The charge collection map was normalised based on taking the ring shown to be 100% charge collection.
10°

16. Efficiency – TOT Mode (Energy Spectra)
1-12 show ADC counts at positions along cross section from centre to the corners 1 2 3 4 5 6 7 8
7 ADC
30 ADC
7 ADC shared 9 10 11 12
Peaks seen at ~7 and ~30 ADC counts

17. Energy Spectra at varying Bias Voltages
Depleted Region
Depleted Region
Depleted Region
Partially Depleted Region
Depleted Region

18. Energy Spectra with varying Bias Voltage
Only the primary peak is considered.

19. Absolute Efficiency Normal Incidence, 0°
Threshold set just above noise level.
Add description of threshold

20. Absolute Efficiency 2°

21. Absolute Efficiency 4°

22. Absolute Efficiency
10°

23. Conclusions
3D detector successfully operated in X-ray and MIP testbeams.
3D detector shows less charge sharing than the planar equivalent.
Charge collection observed from both inter-column and column-back plane regions.
Charge loss at electrode positions is observed.
As the detector is rotated, the signal equalises across the detector.

24. Full list of authors: G. Pellegrini, C. Fleta, M. Lozano, M.Ullan
R. Bates, A. Mac Raighne, C. Parkes, G. Stewart
Aaron Mac Raighnea, K. C. Akibah, L. Alianellib, M. Artusoj, R. Batesa, F.
Bayer, J. Buytaerte, P. Collinsd, M. Crossleye, L. Eklunda, C. Fletac, A. Gallase,
M. Gandelmani, M. Gersabecka , E.N. Gimenezb, V. Gligorova, T. Husef, M.
Johng, L. F. Llina, M. Lozanoc, D. Maneuskia, J. Marchalb, T. Michelk, M. Nicola,
G. Pellegrinic, D. E. Perirae, R. Plackettd, V .O'Sheaa, C. Parkesa, E.
Rodriguesa, K.J.S. Sawhneyb, N. Tartonib, P. Vazqueze.
a) University of Glasgow, Department of Physics and Astronomy, Glasgow,
UK.
b) Diamond Light Source Ltd, Oxfordshire, UK.
c) Instituto de Microelectronica de Barcelona, IMB-CNM-CSIC, Barcelona,
Spain.
d) CERN CH-1211, Genève 23, Switzerland.
e) Facultad de Fisica , University of Santiago de Compostela, Santiago de
Compostela, Spain.
f) Department of Physics, The University of Liverpool, Liverpool, United
Kingdom.
g) Department of Physics, University of Oxford, UK.
h) Nikhef, Science Park 105, 1098 XG Amsterdam, The Netherlands.
i) Instituto de Fisica, Univ. Federal do Rio de Janeiro, Brazil.
j) Syracuse University, Syracuse, NY 13244, U.S.A.
k) Erlangen Centre for Astroparticle Physics, Universität Erlangen-Nürnberg,
Erwin-Rommel-Str. 1, Erlangen, Germany

25. Synchrotron Tests of a 3D Medipix2 X-Ray Detector, D. Pennicard et al
Synchrotron Tests of a 3D Medipix2 X-Ray Detector, D. Pennicard et al., IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL. 57, NO. 1, FEBRUARY 2010

26. Detection Efficiency with Angle2°
0.32° 4°
10°

27. Relative Efficiencies
The relative efficiency increases towards 100% between 0.32° and 2°.
By 10° the difference between the corner and central efficiencies is much reduced.

28. Energy Spectra at varying Angles
0.32°

29. Energy Spectra at varying Angles2°

30. Energy Spectra at varying Angles4°

31. Energy Spectra at varying Angles
10°

32. Energy Spectra at varying Angles
Position of primary peak in landau distributions.

33. Energy Spectra at varying Bias Voltages

34. Energy Spectra at varying Bias Voltages

35. Energy Spectra at varying Bias Voltages