1. the DAMPE STK G. Ambrosi INFN Perugia

2. The DAMPE Detector Mass: 1480 Kg Power: 600 W Data: 16 Gbyte/day Liftime: 5 years 2

3. FM final integration (06/2015) 3 PSD STK BGO

4. The DAMPE STK Collaboration –University of Geneva, Switzerland –Institute of High Energy Physics, CAS, Beijing –INFN & University, Perugia, Italy –INFN & University, Bari, Italy –INFN & University Lecce, Italy On the time scale of two years the goal has been to design, assemble, test, qualify a Silicon Tracker for a space satellite: use the heritage from AMS 4

5. MOU & schedule 5 MOU signed on April 30 th 2013

6. MOU & schedule –MOU signed on April 30 th 2013 –EQM (Engineering Qualification model) ready by July 2014 –FM (Flight Model) delivered to Shanghai Engineering Center for Microsatellites in spring 2015 –DAMPE is a CERN recognized experiment since March 2014 6

7. Silicon-Tungsten Tracker (STK) Weight: ~ 150 Kg Total power consumption: ~85W 7 Detection area 76cm x 76cm 6 x-y detection layers Outer envelope 1.1m x 1.1m x 23.5 cm Project Leader: X. Wu Technical Coordinator: G. Ambrosi

8. Si Layer and Ladders CFRP plate Top Al honeycomb CFRP frame Tungsten plates CFRP plate bottom Silicon detectors VA140 (front end chip) 12 layers, 6-x and 6-y 192 ladders 768 silicon sensors 1152 ASICs 73728 channels 8

9. STK Structure 12 layers of silicon micro-strip detector mounted on 7 support trays – Tray: carbon fiber face sheet with Al honeycomb core Tungsten plates integrated in trays 2, 3, 4 (from the top) – Total ~1 X 0 for photon conversion 8 readout boards on 4 sides 9

10. 10 STK mechanical structure Tungsten Tungsten Tungsten Steel insert Sensitive layer 940 mm

11. Si Ladder and Layer 192 ladders 768 silicon sensors 1152 ASICs 73728 channels 11 12 layers, 6-x and 6-y 76 cm 38 cm

12. Ladder Assembly Work Flow 12

13. Ladder Assembly Precise jigs to assemble (align, glue and bond) 4 sensors to a ladder – 20 µm alignment precision and planarity 13

14. FM STK integration (03-04/2015) 14

15. Several Layers 15

16. the Silicon Tracker 16 April 10 th 2015

17. the Silicon Tracker 17 April 10 th 2015

18. FM STK integration (04/2015) 18

19. Tracker readout Board(TRB) 8 compact TRB modules were used to readout 73728 channels. Each module consists of ADC board, Power board and FPGA board in which data compression algorithm code was implemented in. Power consumption of STK: 82W (TFH:22W TRB: 60W) Readout and Power electronics (IHEP)

20. the Silicon Tracker 20 April 27 th 2015 IHEP clean room

21. DAMPE STK group 21

22. STK Full Plane Test (04/2014) 22 SERMS laboratory in Terni (Italy) Vibration and TV test of EQM planes

23. STK vibration and TV test 23 SERMS laboratory in Terni (Italy)

24. Acceptance test in Beijing 24

25. Test beam activity at CERN (nov ’14 - nov’15) 14days@PS ， 29/10-11/11 2014 – e @ 0.5GeV/c, 1GeV/c, 2GeV/c, 3GeV/c, 4GeV/c, 5GeV/c – p @ 3.5GeV/c, 4GeV/c, 5GeV/c, 6GeV/c, 8GeV/c, 10GeV/c –  -@ 3GeV/c, 10GeV/c –  @ 0.5-3GeV/c 8days@SPS ， 12/11-19/11 2014 – e @ 5GeV/c, 10GeV/c, 20GeV/c, 50GeV/c, 100GeV/c, 150GeV/c, 200GeV/c, 250GeV/c – p @ 400GeV/c (SPS primary beam) –  @ 3-20GeV/c –  @ 150GeV/c, 17days@SPS ， 16/3-1/4 2015 – Fragments ： 66.67-88.89-166.67GeV/c – Argon ： 30A- 40A- 75AGeV/c – Proton ： 30GeV/c ， 40GeV/c 21days@SPS ， 10/6-1/7 2015 – Primary Proton: 400GeV/c – Electrons @ 20, 100, 150 GeV/c –  @ 50, 75, 150 GeV/c –  @ 150 GeV /c –  + @10, 20, 50, 100 GeV/c 10days@SPS, 11/11-20/11 2015 -- Pb 30AGeV/c (and fragments) (HERD) 6days@SPS, 20/11-25/11 2015 -- Pb 030 AGeV/c (and fragments) 25

26. Silicon Sensor and Front End Electronics Silicon strip detectors produced by Hamamatsu Photonics – 9.5 x 9.5 cm 2 – 320±15 µm thick – 768 strips with 121 µm pitch – Resistivity 5-8 kΩ, V fd 10-80 V – ~ 150 nA, max 280 nA VA140 chip (AMS like) produced by IDEas – 64 channel per chip – Readout pitch 242 µm 26 Parameter VA64HDR9A VA140 Noise, Cd=50pF (eRMS) 520 430 DNR +100fC,-200fC ± 200fC Power cons. (mW/channel) 0.8 0.29 SEL thrshd (MeV∙cm 2 /mg) 22 21-22

27. 27 The bulk of the channels of lower noise in orbit because of lower temperature – STK has similar noise behavior as on ground Noise comparison: end of aging test vs in orbit

28. 28 Noise in orbit 118 channels (0.16%) noise > 10 ADC 257 channels (0.34%) noise > 5 ADC 20160118-Now!

29. 29 Temperature stability on orbit TFH(SSD) temperature: 3~6 ℃ TRB temperature: -3~3 ℃ Temperature variation<1 ℃ for 1 month

30. STK spatial resolution after alignment on ground 30 Track inclination (deg) σ of major gauss (μm)

31. 31 Same performance as on ground (test beam and cosmic test) Cluster signal on orbit (first look at the data)

32. 32 spatial resolution and charge ID on orbit Preliminary, low statistics Preliminary, low statistics

33. Characteristics of HERD tracker typesizeX 0, λunitmain functions tracker (top) Si strips70 cm × 70 cm 2 X 0 7 x-y (W foils) Charge Early shower Tracks tracker 4 sides Si strips65 cm × 50 cm 2 X 0 7 x-y (W foils) Charge Early shower Tracks 33

34. 34 3D CALO e/G/CR energy e/p discrimination STK(W+SSD) Charge gamma-ray direction CR back scatter DAMPE and HERD Detectors Plastic Scintillator Detector Silicon-Tungsten Tracker BGO Calorimeter