CBM Silicon Tracking System. Microstrip Detector Module Assembly and Test

1. V.M. Pugatch Kiev Institute for Nuclear Research CBM Silicon Tracking System.Microstrip Detector Module Assembly and Test GSI (CBM experiment), Darmstadt April 20th ‘07

2. KINR – CBM(CooperationAgreement, 2007-2008) • 4 KINR employees contribute currently into the CBM – activity • Design , production and test measurements of sensors, hybrids, ladders cooling elements for the silicon microstrip detector modules, in collaboration with Institute of Microdevices (Kiev), Institute of Applied Physics (Sumi), SPA “DETECTOR” (Kiev) • Design and construction of the system for the Quality Assurance • Evaluation of the possibility for Radiation hardness studies • Design of the Radiation Monitoring System based on the Metal Foil Detector technology • Design of the Metal Microstrip Detectors for the beam diagnostics (position, intensity distribution, beam stabilization) • Theoretical studies of the quark-gluon plasma phenomena.

3. KINR • National Academy of Science of Ukraine • Institute for Nuclear Research • Kiev • Equipment: Isochronus Cyclotron U-240 (protons up to 70 MeV and HI) Nuclear Reactor (10 MW) Tandem Generator (10 MV) Cyclotron U-120 – 27.2 MeV alpha-particles and HI.

4. Silicon Detectors activity at KINR • Since 1960 at the Radiation Physics Department (Prof. I. Konozenko, Dr. Litovchenko, Dr. A. Rosenfeld, …) • 1986 – Submicron position resolution at the interstrip gap of the microstrip silicon detectors • 1990 –2006 SPA “DETECTOR” & IMD – Si – detectors for different experiments at DESY, CERN, HASYLAB, NIKHEF, KINR …

6. r/o 8 cm 4 cm 4 cm 2 cm dead zones  overlaps principle of "long-ladder" design J. Heuser thickness: 200 µm Si + 3100 µm Kapton + 3  20 µm Al : ~ 400-500 µm Si equiv. flat cable: challenge!!

7. Microstrip Detector Module Prototype. R&D tasks for the year 2007 Design and production of : • Double-sided microstrip silicon sensors (with key specifications similar to the CBM Silicon Tracking System (thickness – 300 µm, active area – 73 × 40 mm2, number of strips – 2 × 768, strip width – 38 µm, strip pitch – 95 µm, full depletion voltage – 70 V, leakage current – 2 nA/strip, breakdown voltage – 100 V, AC-coupling ) – 1 sample is available from the IMD (Kiev) • Support structure (carbon fiber) ( material budget not exceeding the one of the sensor, i.e. 0.3% X0) – designed and ordered at the AEROPLAST (Kiev) • Microcable (30 cm long, 768 lines, 95 µm pitch, connecting a silicon sensor with readout electronics) – designed and ordered at the IMD (Kiev) (currently - 4 x 7.5 cm = 30 cm, later – as a single 30 cm long cable) • Pitch adapter (95 µm to 50.7 µm, connecting a r/o cable to r/o chips) – not yet specified ??? • Hybrids for readout chips and RC filter circuits. (The readout chips will be provided by GSI) – not yet specified ??? • Cooling infrastructure and temperature monitoring - designed and ordered at the AEROPLAST (Kiev)

8. SENSOR-> ALICE prototypedouble-sided Si detector, 768 strips (95 µm pitch),73x40 mm2 active area n- side p- side

9. Supporting frame (ladder) –carbon fiber • Samples ordered at AEROPLAST (Kiev)

10. AEROPLAST (Kiev)

11. AEROPLAST (Kiev) - a possibility of a design and production of big supporting frames/boxes (ST – LHCb type)

12. LHCb Silicon Tracker – supporting boxes with cooling pipes Cooling infrastructure and temperature monitoring for the CBM detector module to be built soon at the AEROPLAST (Kiev). Cooling inside of the supporting ladders is also under consideration

13. Microcable (30 cm long, 768 lines, 95 µm pitch, connecting a silicon sensor with a readout electronics) – ordered at the IMD (Kiev) (currently - 4 x 7.5 cm = 30 cm, later – as a single 30 cm long cable) Institute of Microdevices (Kiev) Microcables may have up to few hundreds of leads up to 36 microns wide, leads pitch - up to 80 microns; Cables withstand up to 100 000 double bends with radius of 5 mm temperatures from - 19 to + 250 deg. С. Methods of assembling – ultrasonic bonding ( Al, Cu, Ni, Ag, Au coats) or fluxless soldering;

14. Uncertainties for the module prototype construction • Pitch adapter (95 µm to 50.7 µm, connecting a r/o cable to r/o chips) – not yet specified ??? • Hybrids for readout chips and RC filter circuits. (The readout chips will be provided by GSI) – not yet specified ???

15. Pitch Adapter - flat cable – after clarification - production at the Institute of Microdevices - Similar to the LHCb – pitch adapter (Ch. Bauer)

16. ASSEMBLY of the Module prototype • 1st prototype – the design similar to the long ladders of the LHCb Silicon Tracker – modified for the double-sided version of sensors • Real devices - at the IAP NASU (Sumi).

17. Mechanical Assembly of Real CBM Modules– a possibility at the mechanical Workshop of the Institute for Applied Physics, NASU – Construction of mechanical assembling tools as on the picture was discussed.

18. Prototype Module assembly scheme-similar to the HERA-B double-sided Supporting frames – separated: two for hybrids with readout chips and one for the Sensor (to prevent heating of the sensor)

19. Prototype Module: assembly scheme

20. Supporting frame for the sensor, flat cable, cooling plate and hybrid

21. TEST – Quality assurance system - final goal What has to be checked: Mechanical mounting Electrical connections Cooling flow, temperature What has to be tested/measured (quality assurance): Operating channels Full depletion voltage Leakage currents Signal/Noise OUTCOME:Map of the operating channels of the CBM tracker.

22. Ru-106 – source . MIP – hit triggering (two PM coincidences). TEST – Quality Assurance Signal/Noise Ru-106 РС – interface PC Pentium 1200 MHz PM-1 Si-det. PM-2 Test Setup built and running at the KINR for (8 x n) channels

23. Test setup for signal flow Photo of the test setup built at The MPI f K (Heidelberg) (+ cooling & vacuum).

25. Laser test setup LHCb Laser setup at Zurich University – Measuring in atmosphere

26. TEST - Quality Assurance at KINR Charge, Strip ” k” Ra-226, 4 lines – alpha-source. Interstrip gap – strips functionality, charge sharing, full depletion voltage, leakage current: Eight channels Test setup at KINR – built and running with discrete Electronics. Charge, Strip “k+1”

27. Conclusions. Outlook • Prototype Detector Module (one double-sided Si microstrip detector) is designed. Main components are ordered – to be ready by July ’07 • Test setup based on the discrete readout electronics (106Ru- MIP-PM) is built and ready for applications: - sensor/support-infrastructure/flat-cable performance, long term stability etc., • Laser test setup – available by the October ’07 • Real Modules assembly and their Quality Assurance could be provided by KINR in collaboration with IMD (Kiev) IAP (Sumi) and AEROPLAST (Kiev).

28. Attachement -1Metal Microstrip Detector for the beam profile monitoringat the CBM experiment • MMD – principle of operation

29. Metal Microstrip Detector for the beam profile monitoringat the CBM experiment • Photo of the 32 channels MMD (KINR & IMD production) 32 Nickel strips. 2 µm thick, 40 µm wide, 70 µm pitch. 1024 strips,1µmthick, 25 µm wide, 50 µm pitch – under construction

30. Metal Microstrip Detector for the beam profile monitoringat the CBM experiment Beam profile measured by MMD at HASYLAB (DESY).