1. Engineering Design Review: Fibres, Mats and Modules Heidelberg 16 & 17 July 2015 1.Introduction 2.Fibres 3.Fibre Mats 4.Modules 5.Interfaces 6.Test beam results 7.General planning LHCb SciFi LHCb / DT Meeting C. Joram 20 July 2015 1 LHCb Scintillating Fibre Tracker Engineering Design Review Report: Fibres, Mats and Modules (126 pages) LHCb-PUB-2015-008 10th July 2015 https://indico.cern.ch/event/406444/attachments/1124597/1605089/main.pdf Acknowledgements / apologies: many slides stolen from my SciFi colleagues (Uli, Blake,…)

2. Replace Inner (silicon) and Outer (straws)Tracker: high granularity (like Si strips) homogenous low mass (~10%X 0 ) fast (25 ns) Scintillating Fibre detector w/ modular design Inner and Outer Tracker 2

3. 3 Modular Design Station T i X U V X 3 stations w/ 4 layers Fibre direction 360 m 2

4. 4 Basic Element: 6-Layer Fibre Mat Fibre direction 130.65mm 2.42m mirror Connect SiPM 275  m Fibre: Kuraray SCSF-78M Ø 250  m Detected light-yield: 23 p.e. for MIP near SiPM 16 p.e. for MIP near mirror

5. 5 SiPM Readout 5 128 (2  64) channel SiPM (Hamamatsu, KETEK) charge weighting algorithms Operation at -40 o C to reduce dark rates

6. Radiation Environment Ionization dose:Neutron fluence 35 kGy in hottest region at SiPMs: 6  10 11 n eq / cm 2 decrease of fibre transparencyIncrease of dark rate 6

7. 7 Fibres: Attenuation length (integral) Kuraray has a similar set-up, however with PMT readout. They measure typically a 10-15% lower value than us. Year  att (m) 2010~3.7 20133.0 20142.6 20153.7-4.0 There was an issue with 2013/2014 fibre samples. Understood and corrected. Semi-automatic set-up at CERN. 1 expon. fit from d = 1 – 3 m. Details in LHCb-PUB-2015-011

8. 8 Light / scintillation yield This very essential parameter can only be determined using ionising radiation, i.e. exposing the fibre to a particle beam or a radioactive source. Details in LHCb-PUB-2015-012 Calibrated in p.e. Manual set-up at CERN. Points at 60 cm are not included in fit

9. 9 Scanning fibre diameter 6 m cleaner LN 3015 AccuScan 6400 cladding Test NI 6009 Fast IO tensioner 50 g unwinding spool rewinding spool (with turn counter) Details in LHCb-PUB-2015-009 CERN (built together with Aachen), which allows to scan fibres with 40  m step size and <1  m resolution. A 12.5 km fibre spool can be scanned in ~3.5 hours. X and Y diameter (look perfect on linear scale)

10. 10 We are able to remove, on average, 1 bump per 1.5 km. No performance loss, just time consuming. Very recently, following improvements in the process, Kuraray announced the production of a spool with only 4 bumps, of which just 2 are >300  m.  We are confident that the bump problem can be further mitigated / solved in the remaining 6 months before series production. 275  m 25  m Only 4 of 6 layers are shown 300  m bump 275  m 350  m bump “Bumps” Major efforts have been made at Kuraray to reliably measure the fibre diameter online during the production. Measurements at Kuraray (online) and by SciFi (offline) agree now to >95%. Spools received in 2014/15 showed typically 20-30 bumps on 12.5 km. Most bumps are just above 300  m, very few are >350  m.

11. 11  irr = 1/(  0 +  irr ) Ionising radiation  Transparency loss of PS  decreasing attenuation length  less light Summary of SciFi irradiation experiments

12. 12 Combination of dose distribution, peaked in the centre, and damage-vs-dose relation let us expect, at the end of the lifetime of the detector, a signal reduction by about 40%. Mitigation strategies: Detector integration design must allow for a replacement of the innermost 24 modules, which see the highest doses NOL fibres for the innermost 24 modules ??? S. A. Ponomarenko et al., Nature Scientific Reports 4, Article number: 6549. Spin-off company Luminnotech First NOL fibre sample promising, but still some way to go. We have (only) 1.5 years left.

13. 13 Mat-Winding Alignment pins on the mat produced through glue filled holes on the wheel Not to scale Alignment pins defines center and fibre direction 3mm

14. 14 Glue Casting of Fibre Mat 14 Pin after casting ~100  m glue on both sides of mats endpieces protection

15. 15 Module-Design 15 Half-panel: Honeycomb (Nomex) + CFRP skin x = 1.0% X 0 4.84 m 0.53 m

16. 16 EDR “deliverables” 1.Quality controlled fibres 2.Winding of 8 6L fibre mats (on prototype machine) 3.Casting of 8 6L fibre mats 4.End cuts + side cuts 5.Mirrors 6.Assembly of 1 dummy (no fibres) module + 1 real module 7.Metrology of dummy module (real module to come) 8.Test beam results of various smaller modules (full length) 9.Definition of interfaces (SiPM, cold box, mounting) 10.Tooling: 1.Fibre diameter scanner + other QA equipment 2.(Industrial) Fibre winding machine 3.Casting tools 4.Module assembly tools 5.Various small tools 11.Production organisation 12.Production planning Dummy module with photogrammetry markers (CERN/BE)

17. 17 Test beam H8 May 2015 Setup 180 GeV beam; mostly pions 4 SciFi modulesAMS laddersTimePix Telescope DUT

18. 18 Light yield Require tracks passing through the DUT (exclude the SiPM gaps) Some concern on the quality of mirroring. A more systematic investigation is starting now. Near the mirror 50cm from SiPM

19. 19 Hit Efficiency @ mirror Probability of finding a hit within 5 channels of the TimePix track Gap excluded from hit efficiency numbers die gap

20. 20 Resolution (track residual) @ mirror Charge weighted Double Gaussian fit σ 1 = 59 μm σ 2 = 203 μm σ eff = 79 μm (weighted average) Mean-charge threshold weighted (simulated PACIFIC) Double Gaussian fit σ 1 = 65 μm σ 2 = 215 μm σ eff = 85 μm (weighted average)

21. 21 Module Centre Production Overview Fibre Quality Centre (CERN) 10,000 km scintillating fibre Fibre Winding Centre Aachen DortmundEPFLKurchatov Tested fibre Module Centre Heidelberg NIKHEF 1300 tested fibre mats 144 tested modules CERN

22. 22 Schedule

23. 23 First reaction of EDR reviewers was very positive! (but let’s wait for their report) In any case … SciFi remains a very challenging project. This EDR covered just a part of the project (no SiPM, ROB, electronics) There are still many engineering and technical issues to settle The light yield (and hence the efficiency) remain a concern.