1. 2 Fraunhofer INT Euskirchen Germany
Radiation tolerant fibres for LHC beam-instrumentation Project and Engineering Aspects
L.K. De Jonge1, T. Wijnands1, J. Kuhnhenn2, S. K. Hoeffgen2, U. Weinand2
1CERN, TS Department
2 Fraunhofer INT Euskirchen Germany
6th LHC Radiation Workshop : November 2007 CERN

2. Radiation tolerant fibres for LHC beam-instrumentation
Outline
Project overview and blowing technique
Dealing with radiation constraints
MC results IR3/IR7
Installation of bypass ducts LHC P4-P3, P6-P7 and P8-P7
Selection and development of radiation resistant fibres
Fujikura fibres the most tolerant
Draka Comteq micro cable production
Installation status IR3/IR7
Fibre monitoring (JDSU/ATLAS system)
Concluding remarks
Radiation tolerant fibres for LHC beam-instrumentation

3. Radiation tolerant fibres for LHC beam-instrumentation
Radiation tolerant fibres for LHC beam-instrumentation

4. Optical cabling with micro ducts
Blow 7mm micro ducts
Blow micro optical cables
Modular and flexible
Easy to replace cables
high precision 25mm polyamide tube
Radiation tolerant fibres for LHC beam-instrumentation

5. Production of 25mm polyamide precision duct
polyamide extruder
production in cooled water under vacuum
Radiation tolerant fibres for LHC beam-instrumentation

6. Blowing of micro ducts and micro cables
blowing of 7x7mm HDPE micro ducts
blowing of a micro cable
Radiation tolerant fibres for LHC beam-instrumentation

7. Beam instrumentation lay-out
Adjacent octant Right
Adjacent octant Left 3 4 3 5 5 4 1 2 3 4 5
Radiation tolerant fibres for LHC beam-instrumentation

8. Beam instrumentation at P3 right (max.3600m)
Radiation tolerant fibres for LHC beam-instrumentation

9. Cable blowing calculation UJ32right (2500m)
Radiation tolerant fibres for LHC beam-instrumentation

10. Blowing speed versus time
Radiation tolerant fibres for LHC beam-instrumentation

11. Blowing test at Draka Comteq factory 2650m
Radiation tolerant fibres for LHC beam-instrumentation

12. Radiation constraints
Early studies were only done for arcs (BI max. 6 dB attenuation)
TCC2 test (500 Gy/ )
Test at Saclay in 2004/Poseidon irradiator CO60 (3 kGy) to test bloweability and confirm attenuation behavior
MC results IR3/IR7 in 2005 (K.Tsoulou et all)
Radiation tolerant fibres for LHC beam-instrumentation

13. MC simulations collimation area IR7
104Gy/yr
Dose rate distributions along the tunnel in Gy/year
Radiation tolerant fibres for LHC beam-instrumentation

14. Radiation constraints
Early studies were only done for arcs
TCC2 test (2500 Gy)
Test at Saclay in 2004/Poseidon irradiator CO60 (3 kGy) to test bloweability and attenuation
MC results IR3/IR7 (rad. levels much higher then arcs)
Standard G652.D 9/125 fibre would not resist
Contract with Fraunhofer INT to select the most tolerant fibre
Screening test
Detailed test with parameter variation (dose rate, temperature, power)
Mixed field test (at CERN TCC2)
QA sample test
New test at Saclay to test only bloweability (300 kGy)
Radiation tolerant fibres for LHC beam-instrumentation

15. Ducts and fibre irradiation Poseidon/Saclay 3/300 kGy
Radiation tolerant fibres for LHC beam-instrumentation

16. Blowing test at the Draka factory (1000m)
blowing out of cable
test loop 2x1000m
Radiation tolerant fibres for LHC beam-instrumentation

17. Blowing test at the Draka factory (1000m)
re-blowing of a cable
test loop 2x1000m
Radiation tolerant fibres for LHC beam-instrumentation

18. Blowing speed not altered after 300 kGy
Radiation tolerant fibres for LHC beam-instrumentation

19. Microduct test after irradiation at 300 kGy
Radiation tolerant fibres for LHC beam-instrumentation

20. Backup solution with extra ducts
IR 3 : Momentum Cleaning
IR 7 : Betatron Cleaning
Radiation tolerant fibres for LHC beam-instrumentation

21. Beam instrumentation lay-out extra ducts P7left-right
from P6
from P8 1 2 3 4 5
Radiation tolerant fibres for LHC beam-instrumentation

22. Bypass ducts (5) blowing P4 to P3 2800m
Radiation tolerant fibres for LHC beam-instrumentation

23. Fraunhofer study Fibre and cable production
Draka and Fujikura developed the 2 most tolerant fibres
normal Draka G652.D 9/125 fibre already very good
Finally Fujikura developed the best radiation resistant fibre
first production of 500 km for 7BI-right
contract with Fujikura for 2000 km for 7BI-left and 3BI-right
production rate 300 km/month
to improve production lengths CERN accepted α ≤0.5 dB/km
Draka Comteq produced the micro cables (8, 12 and 24 fibres)
total of ~250 km cable produced and delivered at CERN
7BI has been finished just in time before cooling this sector
3BI-right remains to be done just within LHC schedule
Radiation tolerant fibres for LHC beam-instrumentation

24. Beam instrumentation radiation monitoring
Adjacent octant Right
Adjacent octant Left 3 4 3 5 5 4 1 2 3 4 5
Radiation tolerant fibres for LHC beam-instrumentation

25. Fibre monitoring system ATLAS/JDS-Uniphase
to other
cables under
test
OTAU
OTDR
λ1550 nm
Optical Switch
Optical Time Domain Reflecto meter
RTU Remote Test Unit
OTx
ORx
Cable under test
System Management
up to 100 km long
Internet
CERN intranet
WEB Client
Radiation tolerant fibres for LHC beam-instrumentation

26. Radiation tolerant fibres for LHC beam-instrumentation
Concluding remarks
Confident that the radiation aspects have been properly addressed
BI problem solved (total attenuation will remain under 6 dB, BI constraint)
Bypass ducts available as backup solution
Communication fibres no problem either (larger power margins)
Project successful
The blowing technology has proven to be the right choice
Excellent and productive collaboration CERN, Fraunhofer and Industry
Fair and tough competition between Draka and Fujikura to develop the most tolerant single-mode optical fibre
Fibre and cable production by industrial process (repeatable)
Looking forward to finalize our studies (report)
Further studies
Fibre monitoring
Collaborations
Radiation tolerant fibres for LHC beam-instrumentation

27. Radiation tolerant fibres for LHC beam-instrumentation
And last but not least
Many thanks to
Fraunhofer INT/DE
Studies and measurements
Draka Comteq Telecom/NL
Optical fibre supply and installation contract
Mauerhofer&Zuber/CH
Optical fibre installer
Fujikura Ltd/GB and Japan
Radiation resistant optical fibre production
CERN and colleagues involved
And special thanks to Thijs Wijnands and Jochen Kuhnhenn
Radiation tolerant fibres for LHC beam-instrumentation