Status of the Micro Vertex Detector of the CBM Experiment N. Bialas 1, N. Chon-Sen 2, G. Claus 2, C. Colledani 2, R. De Masi 2, M. Deveaux 1, D. Doering 1, M. Domachowski 1, A. Dorokhov 2, C. Dritsa 1;2;3, W. Dulinski 2, H. Düring 2, J. C. Fontaine 2, I. Fröhlich 1, T. Galatyuk 1, M. Goffe 2, A. Himmi 2, C. Hu 2, K. Jaaskelainen 2, M. Koziel 2, J. Michel 2, F. Morel 2, C. Müntz 1, S. Ottersbach 1, F. Rami 2, 1 P. Scharrer 1, C. Schrader 1, S. Seddiki 1;2, M. Specht 2, J. Stroth 1, T. Tischler 1, C.Trageser 1, I. Valin 2, F. M. Wagner 4, B. Wiedemann 2, and M. Winter 2 1 Institut für Kernphysik, Goethe Universität Frankfurt am Main — 2 Institut Pluridisciplinaire Hubert Curien (IPHC), Strasbourg/France — 3 GSI, Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt — 4 Forschungsneutronenquelle Heinz-Maier-Leibnitz (FRM II), Technische Universität München

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 2 Sensors for the MVD CBM wish list MAPS* (2003) MAPS* (2009) MIMOSA-26 Binary, 0 Single point res. ~ 5 µm1.5 µm1 µm4 µm Material budget < 0.3% X 0 ~ 0.1% X 0 ~ 0.05% X 0 Rad. hard. non-io. >10 13 n eq n eq /cm²>3x10 13 n eq few n eq Rad. hard. io > 3 Mrad200 krad> 1 Mrad> 300 krad Time resolution < 30 µs~ 1 ms~ 25 µs110 µs Optimized for one parameter Current compromise Monolithic Active Pixel Sensors (MAPS, also CMOS-Sensors) Invented by industry (digital camera) Modified for charged particle detection since 1999 by IPHC Strasbourg Also foreseen for ILC, STAR… => Sharing of R&D costs.

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 3 Chapter 1 Sensor R&D

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 4 Radiation hardness studies Undepleted MAPS Depleted MAPS Radiation tolerance of MAPS as function of pixel pitch Sensor ok if det. eff > 95%

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 5 Sensor R&D: MIMOSA-26 Analog pixel outputs for tests JTAG slow control On-chip voltage generators 1152 discriminators zero suppr. logic Output memories 3 mm Suited for up to 9 hits/line => ~ 1% occupancy 21.2 x 10.6 mm² 18.6 µm pixel pitch

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 6 First analysis results 6 Mimosa26 Spectrum Mimosa26 Noise First tests successfully performed at T= -20°C and. Preliminary D. Doering

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 7 Comparison standard and depleted sensor 7 Fe-55 4 pixel cluster T=-20°C Shift after irradiation No shift Very uniform charge collection properties but: Strong radiation effect. Sensor not uniform (as partially depleted): Reduced radiation effect. D. Doering

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 8 Sensors for the MVD CBM wish list MAPS* (2003) MAPS* (2009) MIMOSA-26 Binary, 0 Single point res. ~ 5 µm1.5 µm1 µm4 µm Material budget < 0.3% X 0 ~ 0.1% X 0 ~ 0.05% X 0 Rad. hard. non-io. >10 13 n eq n eq /cm²>3x10 13 n eq few n eq Rad. hard. io > 3 Mrad200 krad> 1 Mrad> 300 krad Time resolution < 30 µs~ 1 ms~ 25 µs110 µs Optimized for one parameter Current compromise Monolithic Active Pixel Sensors (MAPS, also CMOS-Sensors) Invented by industry (digital camera) Modified for charged particle detection since 1999 by IPHC Strasbourg Also foreseen for ILC, STAR… => Sharing of R&D costs.

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 9 Annealing studies with combined radiation irradiated MAPS 9 Temperature profile T[°C] Time 20°C 80°C Neutron radiation 1 year X-ray radiation Measurements at T=20°C (280h) Heating at T=80°C (73h) Measurements and storage at T=20°C (191h) 2h transport D. Doering

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 10 Annealing studies Annealing dims ionizing radiation substantially No trace of reverse annealing (yet) => Recover detector on the fly(?) D. Doering

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 11 Chapter 3: Data rates and performances 1 fake hit / hit in the MVD Measurement of the dark rate of irradiated MIMOSA-18 hits/pixel/readout M. Domachowski To be used as input for the MVD-Digitizer

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 12 Chapter 2: System integration (1)

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 13 Design of a ladder for the MVD CBM-Acceptance Low material 5 cm

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 14 Steps of a system integration: The MVD-Demonstrator Idea Thermal simulation CAD-Design Construction Power: ~ 1W /cm²

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 15 Achievements: System design validated Good noise: 21 e - ENC Spatial res.: < 6µm Steps of a system integration: The MVD-Demonstrator Construction CERN-SPS (Nov 2009) signal (a.u.) Shadow of trigger scintillator Preliminary Demonstrator project accomplished S. Amar-Youcef

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 16 Towards the MVD: HP-2 ULISI Build an ultra thin ladder. Partners: IPHC, IKF, IMEC Chip on polyamide: Technology demonstrator by IMEC, Belgium Build a “prototype” with: Fast digital sensors FEE/DAQ for multiple sensors “Close to real detector” performance

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 17 Towards the MVD: HP-2 ULISI Diamond µm ~ 60 (1) -150 (2) µm Si < 200 µm Si ~ 60 (1) -150 (2) µm Si ~ 320 (1) -500 (2) µm Si PolyamideSensorMetal lines Build an ultra thin ladder. Partners: IPHC, IKF, IMEC (1) first MVD station (2) last MVD station Project kick off: Dec First Prototype: Apr First results: End 2010

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 18 Chapter 2: Simulation

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 19 Open charm simulation with delta-electrons and pile-up Thickness of sensors - Geometry used –Pixel pitch : 18.4 × 18.4 µm 2 (From MIMOSA 26) Time resolution = 30 µs (MIMOSIS-2) StationZ [cm] Thickness [µm] R inner [mm]R outer [mm] Collision rate (interactions/s) Collisions/year (mbias) D 0 →π + K - (generated) * No pile up3 · · Pile up 51.5 · · C. Dritsa

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 20 Analogue readout: PV sigma Pile Up Signal Efficiency (PV>3) Background rejection (PV>3) %99.4 % %98.0 % %92.2 % C. Dritsa

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 21 Hit merging and track reconstruction 1: High P track 2: Low P track MVD STS The high P track will be reconstructed first and will “own” the hit. The track parameters will be slightly modified. Hit sharing is not implemented in the MVD: The low momentum track does not “find” the hit. There is a probability to pick up a wrong neighbouring hit (?) C. Dritsa

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 22 Open Charm reconstruction No pile-up C. Dritsa

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 23 ~ 2500 D 0 ~ 700 D 0 Significance Operating with pile-up seems mandatory but: Hardware has to be optimized – review detector position and geometry Pattern recognition should be studied – reduce background C. Dritsa

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 24 Chapter 3: FEE and DAQ

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 25 Data rates for 1.5 x 10 5 coll/s Data rate of the sensors was simulated accounting for: pile-up, delta electrons, clustering, fake hits rates, data protocols.... S. Seddiki No multiplexers in vacuum vessel (cooling, radiation dose) => more than 200 differential links ( > 10 GB/s compressed data) 100 GB/s for 3D-Sensors S. Seddiki

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 26 DAQ-system for the MVD Slow control: JTAG Time stamping Sensor Control Data concentration FPGA based: Cluster finding (?) Fake rejection (?) Pattern recognition (?) PC interface: 4x 3.8 Gbit/s GPU based data processing Interface to FLES All hardware components shown are available (HADES TRBNet) Prototype MVD-DAQ: Compact radiation hard and vacuum compatible FEE-boards System validation (Firmware, Data concentration algorithms) Speed up TRBNet (So far designed for 200 MB/s with 2 Gbit/s links) C. Schrader

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 27 Summary and Conclusion The MVD – demonstrator project was successfully completed. Readout chain shows good noise performance in beam Spatial resolution obtained in beam test fits CBM-requirements The feasibility of open charm reconstruction with pile-up 5 and delta electrons was demonstrated => 1.5 x 10 5 coll/s with MIMOSIS-2. Relatively high background => Improve hit finder, MVD-tracking. High occupancy: Review mag. field, detector position Radiation hardness tests are progressing: Test of MIMOSA-26 HR show first promising results Annealing tests suggest that ionizing radiation damage can be partially recovered in installed detector. Outlook: Build prototype with “close to real detector”-performance Study silicon in polyamide technology => would match material budget goals Study realistic FEE-DAQ based on Hades TRBNet

M. Deveaux, 15th CBM collaboration meeting, 14th April 2010, GSI 28 Backup