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Tony Weidberg ATLAS/CMS Opto WG March '11 1 Oxford R&D Cold Fibre radiation tests Splitter and connector radiation tests Fibre reliability after radiation Core Cladding cables Reliability testing for iFlame Batch testing in production
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Tony WeidbergATLAS/CMS Opto WG March '111 Oxford R&D Cold Fibre radiation tests Splitter and connector radiation tests Fibre reliability after radiation.

Jan 14, 2016

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Page 1: Tony WeidbergATLAS/CMS Opto WG March '111 Oxford R&D Cold Fibre radiation tests Splitter and connector radiation tests Fibre reliability after radiation.

Tony Weidberg ATLAS/CMS Opto WG March '11 1

Oxford R&D

• Cold Fibre radiation tests

• Splitter and connector radiation tests

• Fibre reliability after radiation– Core– Cladding– cables

• Reliability testing for iFlame

• Batch testing in production

Page 2: Tony WeidbergATLAS/CMS Opto WG March '111 Oxford R&D Cold Fibre radiation tests Splitter and connector radiation tests Fibre reliability after radiation.

Tony Weidberg ATLAS/CMS Opto WG March '11 2

Cold Fibre Radiation Tests (1)

• Want to qualify two sources for SM and MM fibres.• Suitable fibres passes radiation tests when operated

warm but damage more significant cold.• Cold fibre radiation tests

– First tests at Rita with low dose with Peltier cooler• Damage larger than warm but extrapolation to full dose

uncertain inconclusive

– Full SLHC dose at Brigitte– Two SM fibres passed tests qualified.– Other SM fibre and MM fibres showed large damage but

dose rate unrealistically high results inconclusive.

Page 3: Tony WeidbergATLAS/CMS Opto WG March '111 Oxford R&D Cold Fibre radiation tests Splitter and connector radiation tests Fibre reliability after radiation.

Cold Fibre RIA (1)

• Two SM fibres qualified for cold operation (-25C).

Tony Weidberg ATLAS/CMS Opto WG March '11 3

Draka SRH-SMFProducer X

Page 4: Tony WeidbergATLAS/CMS Opto WG March '111 Oxford R&D Cold Fibre radiation tests Splitter and connector radiation tests Fibre reliability after radiation.

Cold Fibre (2)

• MM fibres not yet qualified

• Infinicor SX+ qualified from warm radiation tests.

• Results inconclusive

• Further tests at lower dose rates

Tony Weidberg ATLAS/CMS Opto WG March '11 4

Page 5: Tony WeidbergATLAS/CMS Opto WG March '111 Oxford R&D Cold Fibre radiation tests Splitter and connector radiation tests Fibre reliability after radiation.

Tony Weidberg ATLAS/CMS Opto WG March '11 5

Cold Fibre Radiation Tests (2)

• Plan for long radiation test at Rita– > 10 day run @ 1 kGy/hour– Use liquid CO2 for blow-off cooling system– Optimise the system, length of capillary.– Run with 3 bottles and replace one every 24 hours– Hope to run this summer if safety accepted at

SCK.

• Combine results with very low dose rate tests by SMU at BNL?

Page 6: Tony WeidbergATLAS/CMS Opto WG March '111 Oxford R&D Cold Fibre radiation tests Splitter and connector radiation tests Fibre reliability after radiation.

Tony Weidberg ATLAS/CMS Opto WG March '11 6

Splitter Radiation Tests

• Samples of two commercial splitters and other samples irradiated at Mega Curie source (Taiwan) to beyond full SLHC dose (500 kGy).

• Measurements performed before and after radiation.– Show results for next VL meeting

Page 7: Tony WeidbergATLAS/CMS Opto WG March '111 Oxford R&D Cold Fibre radiation tests Splitter and connector radiation tests Fibre reliability after radiation.

Tony Weidberg ATLAS/CMS Opto WG March '11 7

Connector Tests

• Test LC and MT/MPO connectors before and after radiation.

• Simple insertion loss measurements.• Before radiation tests of MT/MPO performed.• Repeat equivalent tests for LC connectors • Irradiate to 500 kGy at Mega Curie source.• Repeat measurements after irradiation.

Page 8: Tony WeidbergATLAS/CMS Opto WG March '111 Oxford R&D Cold Fibre radiation tests Splitter and connector radiation tests Fibre reliability after radiation.

Tony Weidberg ATLAS/CMS Opto WG March '11 8

Fibre Reliability Testing

• Fibre manufacturers have performed extensive reliability testing but very little is known about reliability after radiation.

• Need to study core (glass) and buffer separately.

• n – the corrosion susceptibility

• m – the Weibull parameter

Page 9: Tony WeidbergATLAS/CMS Opto WG March '111 Oxford R&D Cold Fibre radiation tests Splitter and connector radiation tests Fibre reliability after radiation.

Tony Weidberg ATLAS/CMS Opto WG March '11 9

Pull Testing for Core• Measurements of pull strength for fibre samples

can be used to check fibre reliability.• Measure many samples at a fixed pulling speed

Weibull analysis• Measure median pull strength at different

pulling speeds stress corrosion parameter.• Determine n and m before and after irradiation.

– Also compare with manufacturer’s specs.

Page 10: Tony WeidbergATLAS/CMS Opto WG March '111 Oxford R&D Cold Fibre radiation tests Splitter and connector radiation tests Fibre reliability after radiation.

10

The pull tester(polycarbonate shield protects against flying shards when the fibre

fractures)

Clamps & capstans

Page 11: Tony WeidbergATLAS/CMS Opto WG March '111 Oxford R&D Cold Fibre radiation tests Splitter and connector radiation tests Fibre reliability after radiation.

Tony Weidberg ATLAS/CMS Opto WG March '11 11

Weibull Plot ConstructionCollect sample of pull test strengths for a speed of 50mm/min.

The “intrinsic distribution” from which the m-value is determined

The “extrinsic distribution”, due to infrequent weak spots caused by contamination by dust & other factors during the manufacturing process

Page 12: Tony WeidbergATLAS/CMS Opto WG March '111 Oxford R&D Cold Fibre radiation tests Splitter and connector radiation tests Fibre reliability after radiation.

Tony Weidberg ATLAS/CMS Opto WG March '11 12

Our acceptable n-plot for SMF 28: gives a realistic value for n of 25.5

Our unacceptable n-plot for Infinicor SX+: gives an uncharacteristically low value for n of 14.8

n values from fit of mean pull strength vs. speed.

Page 13: Tony WeidbergATLAS/CMS Opto WG March '111 Oxford R&D Cold Fibre radiation tests Splitter and connector radiation tests Fibre reliability after radiation.

Tony Weidberg ATLAS/CMS Opto WG March '11 13

Next steps

• Repeat pre-irradiation tests for Infinicor SX+, – irradiaite SMF28 and Infinicor to 500 kGy at

Mega Curie– Repeat measurements after irradiation.

• Perform these measurements for fibres selected as qualified from cold radiation tests.

Page 14: Tony WeidbergATLAS/CMS Opto WG March '111 Oxford R&D Cold Fibre radiation tests Splitter and connector radiation tests Fibre reliability after radiation.

Tony Weidberg ATLAS/CMS Opto WG March '11 14

Buffer Quality• Buffer is important to take stress

from any micro-bending of fibre controlled micro-bending test.

• Wind the fibre onto a drum with correct grade of sandpaper microbending and measure increase in attenuation with OTDR.

• Before and after irradiation tests,• First trial with Draka fibre performed

by Bertil Arvidsson at Fibreson.• Use this test for all fibres that pass

cold fibre radiation qualification,

Page 15: Tony WeidbergATLAS/CMS Opto WG March '111 Oxford R&D Cold Fibre radiation tests Splitter and connector radiation tests Fibre reliability after radiation.

Tony Weidberg ATLAS/CMS Opto WG March '11 15

Fibre Cables

• Plan to use Birmingham cyclotron – 26 MeV protons penetrate fibre– Scanning table constructed will allow 1m

of cable to be irradiated to SLHC fluence/dose.

– First try in April to look for any dramatic effects on Ericsson and Fujikura cable

• Ask Fibresson to perform before and after pull testing.

Page 16: Tony WeidbergATLAS/CMS Opto WG March '111 Oxford R&D Cold Fibre radiation tests Splitter and connector radiation tests Fibre reliability after radiation.

Tony Weidberg ATLAS/CMS Opto WG March '11 16

Batch Testing in Production

• Fibres– Need to perform cold radiation test on fibres from

every spool.– Can we use lower dose for this QA step?

• Mechanical testing– Will this be required on production batches?

• Connectors and splitters– Radiation tests of samples from production,