The CBM-MVD prototype: Realization & beam test Michal Koziel Goethe-Universität, Frankfurt 1 Detector Workshop March 25th-26th 2013 at GSI

Outline 2  CBM experiment and its requirements  Prototyping the CBM-MVD  Mechanical integration  Readout electronics and DAQ  Data analysis  Summary and outlook

Required performances (SIS-100) Radiation tolerance > n eq /cm 2 & >1 Mrad Read-out speed> 30 kframes/s Intrinsic resolution< 5 µm Operation in vacuum „Light” support and cooling Material budget ~ 0.3 % X 0 CBM-MVD will: -improve secondary vertex resolution -background rejection in di-electron measurements -host highly granular silicon pixel sensors featuring fast read-out, excellent spatial resolution and robustness to radiation environment. 3 The MVD – required performances MVD Up to 4 stations

Sensor R&D DAQ Mechanical integration Sensor R&D System integration Research fields towards the MVD 4 Data analysis IKF infrastructure:  Class (ISO 6) clean room  Grey room  Electronic workshop  Mechanical workshop  Equipment: Manual wire-bonder Probe station 3 microscopes Powerful cooling system Vacuum chamber Prototype highlights:  Develop cooling and support with low material budget employing advances materials  Develop sensor readout system capable to handle high data rates

Material budget: ~ 2.45 % X 0 Sensor: MIMOSA-20 ~200 frames/s few n eq /cm 2 & ~300 kRad 750µm thick Cooling & support: TPG+RVC foam Material budget: ~ 0.3 % X 0 Sensor: MIMOSA-26 AHR ~10 kframes/s ~10 13 n eq /cm 2 & >300 kRad 50µm thin Readout CP/digital/high data rates Cooling & support: pCVD diamond (thermal grade) Readout Serial/analog...will meet all requirements Sensor: synergy with ALICE (diff. geometry) Readout speed: ~30 kframes/s Radiation tol.: >10 13 n eq /cm 2 & >1 Mrad Demonstrator Prototype Final ½ (!) of 1 st station 4 sensors 2012 >2015 Progress towards the MVD Sensor 50 µm Al heat sink CVD diamond Flex Cable 200 µm FEB Encapsulation Wire bonds Glue 200 µm Future MVD: alternated sensors

Main features: -in pixel amplification -binary charge encoding - discriminator for each column - 0-suppression logic -pitch: 18.4 μm - ∼ 0.7 million pixels MIMOSA-26 AHR: 0.35 µm process, High Resistivity (HR) EPI (1 kΩ·cm) Sensors for the MVD prototype 6 Bending radius: ~30 cm Size: 21.2 x 10.6 mm 2 Possible issues:  Internal stress -> long-term reliability  Yield after assembly  Sensor pre-selection with probe cards

Positioning Aspects addressed during prototyping phase Sensor Carrier Glue FPC Sensor integration on CVD diamond: Readout & control Scalability Reliability Adhesive bonding Wire bonding Encapsulation FPC Double sided sensor integration Micro-tracking Beam T1 T2 T3 T4 DUT micro-tracking r/o Plane 2 Plane 1 Plane 4 Plane 3 DUT Cooling Front scintillator Back scintillator Cooling optimization

8 Test beam setup at T1 T2 T3 T4 DUT Beam Material budget: % X 0 Material budget: % X μm CVD diamond 1 mm Al 200 μm CVD diamond

9 DAQ

10 FPC based on MIMOSA-26 AHR FEB... clock start reset JTAG converter board converter board converter board... readout controller board driver board FEB sensors... readout controller board FEB LVDS, 1m 4x 80 Mbit/s LVDS 4 x 80 Mbit/s FPC 2 Gbit/s optical fiber to the MVD network FPC Slow control board Dedicated DAQ Hub readout controller board readout controller board PC General purpose add-on HADES TRB V2 ~30 m Synergy with HADES

Tests before beam time 11  Stability runs  Slow control cross-check  Tests with radioactive sources  Threshold scans  Cooling check  Test with long cables ... Fully operational setup ready for travelling to CERN Laboratory setup Corresponding fluence 24 kHz/cm 2 (limited by source)

12 Full beam setup at SPS Huber cooling system DAQ Beam telescope FEE

DAQ performance during beam tests 13 The Readout Network was proven to be highly scalable. All sensors are synchronized: No deviations detected within 10 ns precision. DAQ runs very stable: No network errors, no data loss (5 days of tests) Data rates: 6 MB/s - 25 MB/s but also overload test with +100 MB/s. JTAG passed also all tests ( programming cycles per chain). In total 2TB of data stored 12 sensors running in parallel Frame number 110 ms ~9 s CERN-SPS Spill structure 40 s9 s  Peak fluence: kHz/cm 2  20% of MIMOSA-26 computing resources used  Factor of 1000 away from peak AuAu 25AGeV Limited by beam

14 Data analysis

15 Data analysis flow: 1.Cluster analysis 2.3D alignment 3.Track selection with the 4-plane telescope (straight lines) 4.Response of DUT to charged particles 20 – 120 GeV Pions CERN SPS North Hall Plane 1 Plane 2 Beam setup beam Plane 3Plane 4 DUT Detection efficiency, Fake Hit Rate, Spatial resolution as a function of threshold voltage (DUT) 4 inclination angles of 0 ,30 ,45 , 60  Temperature (-6, +6, +17  C) & threshold scans High beam intensity runs (in average up to 10 hits/frame but due to the non-uniform beam it could also be ~100 hits / some of frames – to be confirmed)

16 Cluster shape studies Top 8 most frequently observed cluster shapes Cluster classification will be used for further FPGA-based data compression Center of gravity used to compute the “hit” position

Cluster multiplicity studies 17 PRELIMINARY  Charge = 80  EPI th[μm] / cos  [e - ] EPI Sensing diode

Detection Efficiency (DUT) 18 probe V threshold Amplitude time NOISE = individual pixel feature signal noise „safe” region Example: FHR < Efficiency > 95% PRELIMINARY

Spatial Resolution (DUT) Result for the DUT: σ x = 3.3 µm σ Y = 3.3 µm 19 Spatial resolution: DUT only X (row) back sensor Al heat sink FEB 200 µm Front sensor Back sensor π-π- Correlation back - front X (row) front sensor Reproducing the intrinsic parameters of the sensors validates the concept of the prototype. PRELIMINARY

20 Summary & outlook

Summary 21 Mechanical integration Achieved:  An ultra low material budget (0.3% X0) double-sided micro-tracking device: 2x2 sensors, CVD Diamond, glue & FPC.  Development of tools & assembly procedures. DAQ Achieved:  Synchronization  Reliability  Scalability  Slow control & monitoring tools  Data quality Data analysis Achieved:  package for alignment and data analysis for test beam setup (telescope-DUT)  online monitoring software (test beam setup)

Outlook p DAQ Data analysis Towards the CBM-MVD:  Interface to the CBM DAQ  Optical data link between FEE and DAQ board Towards the CBM-MVD:  Optimizing the digitizer based on data on sensor response  Performance studies of physics cases allowing for more realistic studies on detector performance Mechanical integration Towards the CBM-MVD:  Vacuum compatibility and integration into the CBM-MVD vacuum box  design the MVD platform in the target vacuum chamber  cable routing  finalize services (LV, cooling)  Improve in heat transfer.  Quality assurance while assembling (yields)

Outlook p Expertise needed in the future:  Glue: dedicated, radiation tolerant, reworkable, dispensing techniques...  Vacuum: feed-through concepts, MVD stations positioning  Cooling: CO2, or conventional Mechanical integration Synergy with FAIR experiment (...and beyond) needed How to move the MVD stations in vacuum ?

24 Thank you for your attention...