1. Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects Zdenek Vykydal Institute of Experimental and Applied Physics, Czech Technical University in Prague, Czech republic www.medipix.cvut.cz PhD seminar, Řež 26.9.2007

2. Institute of Experimental and Applied Physics Czech Technical University in Prague 26.9.2007 Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects2 Outline Introduction to the Medipix2 detector Principles of detection with counting pixel detectors Medipix2 single particle counting chip USB Read-out interface for Medipix2 chip RELAXd project 3D interconnect technology High density bumping Through silicon via ATLAS-Medipix project Detector network structure Background measurement in ATLAS cavern

3. Institute of Experimental and Applied Physics Czech Technical University in Prague Principle of semiconductor single particle counting pixel detector N+N+ P+P+ Si Counter : Particle count + Amplifier Compa rator 000001 Threshold level above electronic noise  No false counting. Digital integration (counting)  No dark current. Unlimited dynamic range and exposure time. Detected count obeys poissonian distribution Bias Voltage Common back-side electrode Pixelated front-side electrode Pixel electronics Threshold level 26.9.2007 3 Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects

4. Institute of Experimental and Applied Physics Czech Technical University in Prague 26.9.2007 Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects4 Back-side pulse processing: Getting information about energy of interacting particle Detector chip Medipix-2 chip Bias Voltage Preamplifier (charge sensitive) Preamplifier (charge sensitive) Multichannel analyzer Energy [channel] Count Energy spectrum  E E FWHM Trigger

5. Institute of Experimental and Applied Physics Czech Technical University in Prague 26.9.2007 Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects5 Medipix2 detector: Single particle counting pixel detector Medipix2 – MEDical Imaging PIXel detector 2 nd generation  High spatial, high contrast resolving CMOS pixel read-out chip  Array of 256x256 pixels  Pixel size 55x55  m²  Sensitive area of 14x14 mm² (87% of entire chip area)  Amplifier, two discriminators and a 13-bit counter in each pixel cell  Serial or parallel readout at 100MHz  Hybrid technology allows to use different semiconductor sensors www.cern.ch/medipix Medipix2 Single Pixels: 256 x 256 Pixel size: 55 x 55  m 2 Area: 1.5 x 1.5 cm 2 Medipix2 Quad Pixels: 512 x 512 Pixel size: 55 x 55  m 2 Area: 3 x 3 cm 2

6. Institute of Experimental and Applied Physics Czech Technical University in Prague 26.9.2007 Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects6 Bias voltage noise distributionBack side pulse spectrum Combined alpha source: 241 Am + 239 Pu + 244 Cm USB 1.1 interface: Realization and general features  Serial readout speed: 4 fps (4 Mbits/s)  Camera-like size, plug and play, hot swap  Fully USB powered  Integrated source of variable detector bias voltage (5 – 100V)  Advanced triggering and hardware timer  No limit for cable length (various USB extender types)  Back-side pulse monitoring for spectroscopic applications and triggering  Open system architecture - internal analog and digital interface for "plug-in" PCB modules connection www.medipix.utef.cvut.czwww.medipix.utef.cvut.cz

7. Institute of Experimental and Applied Physics Czech Technical University in Prague USB Lite interface Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects  First prototype ready and tested  Single chip 3-side tilable read-out assembly board  Based on USB 1.1 interface  Increased miniaturization  Dimensions: 15 mm x 60 mm 26.9.2007 7 +Low power consumption (no external source) +Portability & flexibility —Performance limitations

8. Institute of Experimental and Applied Physics Czech Technical University in Prague RELAXd project 2005 - 4 months @ NIKHEF, Netherlands 2006/2007 - 6 months @ IMEC, Belgium 26.9.2007 Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects8

9. Institute of Experimental and Applied Physics Czech Technical University in Prague RELAXd project 26.9.2007 Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects9 RELAXd (High Resolution Large Area X-ray Detector) Four-side tilable Medipix Quad modules Serial readout of individual Medipix chip up to 500 MHz Fast serial readout of whole Quad module up to 3.125 Gbps Used technologies:  3D Integrated Electronic Microsystem  Edgeless sensor technology  2D Pitch adaptation between sensor and readout ASIC  CMOS ASIC 200 mm wafer thinning  Through silicon vias made by deep reactive ion etching  BGA bumping instead of wire-bonding  High density Indium bump-bonding  Multi-Gbit/s data transmission to the PC www.nikhef.nl/pub/experiments/medipix

10. Institute of Experimental and Applied Physics Czech Technical University in Prague 3D interconnect technology 26.9.2007 Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects10 The Medipix2 chip was designed as three-side tilable to enable the possibility of building detectors with larger sensitive area. Size of the I/O periphery and commonly used wire-bond technique for signal connection limits the tiling possibilities of the device to 2 row stripes. To overcome this limitation it is necessary to:  Increase the size of the sensor chip to cover I/O area  use pixels with size of about 65 x 65 µm 2 and contacts redistribution (interposer layer or postprocessed metal wiring )  use guardring-less sensor chip  Use another technology for connection of the I/O signals

11. Institute of Experimental and Applied Physics Czech Technical University in Prague High density Indium bumping 26.9.2007 Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects11 Process flow:  Under bump metallization (UBM) deposition and patterning at detector and Medipix2 substrate  In material deposition and patterning at detector and Medipix substrate  Flip-chip integration and reflow

12. Institute of Experimental and Applied Physics Czech Technical University in Prague Through silicon via technology 26.9.2007 Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects12 Newly developed technology to interconnect the front side and back side of the processed silicon wafer  Not application specific  Low temperature process (< 250 °C)  Via resistances in the range of 20 - 30 m  (resistance of conventional wire-bond connection is about 60 m  /mm for 25 µm wire)

13. Institute of Experimental and Applied Physics Czech Technical University in Prague ATLAS-Medipix project 26.9.2007 Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects13

14. Institute of Experimental and Applied Physics Czech Technical University in Prague ATLAS-Medipix project 26.9.2007 Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects14 Main goal is measurement of the radiation field (especially neutron field) in ATLAS experiment MPX01between ID and JM plug MPX02between ID, LARG and JM MPX03between LARG and LARG EC MPX04between FCAL and JT MPX05between LARG and JT wheel MPX06between LARG and JT wheel MPX07top of TILECAL barrel MPX08top of TILECAL EXT. barrel MPX09corner between JF cyl. and hexagon MPX10cavern wall A or C side MPX11cavern wall USA side MPX12cavern wall MPX13between ID and JM plug MPX14between ID, LARG and JM

15. Institute of Experimental and Applied Physics Czech Technical University in Prague Detector network structure 2 options: < 40 m ethernet cable < 60 m CERN LVDS cable Public Ethernet (standard cable) 65m PC with 2 ethernet cards and Linux OS (large HDD for data storage) 26.9.2007 15 PC with Windows OS (up to 8 devices) Power source 20V, 5A PC with Windows OS (up to 8 devices) Power source 20V, 5A PC with Windows OS (up to 8 devices) Power source 20V, 5A Board with switches controlled by 7 th USB port. If any of devices failed in any way it can be physically disconnected. Ethernet switch Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects

16. Institute of Experimental and Applied Physics Czech Technical University in Prague Connection options Medipix US B Detector Ethernet cable <40m with optional power wires (40V) USB extender USB - extender USB interface Medipix Radhard LVDS Mounted in UX15 Detector 10 twisted-pairs (20 wires), plus power wires (4-6V), plus coax for BIAS. <60m LVDS USB interface Mounted in UX15 LVDS cable USB extender  LVDS cable solution  No feedback (DAC out) – THL-FBK values will vary after irradiation, impossible to check  Working up to 60m but it needs software adaptation  USB extender solution  Maximum length ~40m  Tested many times  Full capabilities of USB available (DAC feedback) 26.9.2007 16 Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects

17. Institute of Experimental and Applied Physics Czech Technical University in Prague Protective Box 240 mm 60 mm 25 mm USB extender + optional 40V to 5V converter or LVDS converter instead of USB interface USB extender + optional 40V to 5V converter or LVDS converter instead of USB interface Size of the box was chosed to accomodate both considered connection options 26.9.2007 17 Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects

18. Institute of Experimental and Applied Physics Czech Technical University in Prague First assemblies mounted in ATLAS cavern 26.9.2007 18  17.8.2007 - first two assemblies (MPX07 and MPX11) were mounted in ATLAS cavern  Remote controll (from the internet) of the devices was established and tested  Continuous data acquisition is running from 19.8.2007 measuring natural background in the ATLAS environment Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects

19. Institute of Experimental and Applied Physics Czech Technical University in Prague MPX 07 device MPX07 – Top of the TILECAL barel  Horizontal orientation  Fully opened window  Distance of 16m from UX15  Easily reachable 26.9.2007 19 PE PE + Al Al Uncovered LiF Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects

20. Institute of Experimental and Applied Physics Czech Technical University in Prague MPX 11 device MPX11 – cavern wall USA side  Vertical orientation  Protected with the black tape  Distance of 18m from the UX15  Easily reachable 26.9.2007 20 PE PE + Al Al Uncovered LiF Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects

21. Institute of Experimental and Applied Physics Czech Technical University in Prague Thanks a lot for your attention 26.9.2007 Medipix2-based radiation camera and it's application in RELAXd and ATLAS projects21