1 / 18

Radiation Tests on optical fibres for the LHC machine

Radiation Tests on optical fibres for the LHC machine . T. Wijnands , D. Ricci CERN EN department Fraunhofer INT. First radiation test on optical fibres. December 2002 : First radiation test on SM and MM fibres ~400 Gy total dose (SPS target area) RIA : a few dB/km @ 400 Gy

elijah
Download Presentation

Radiation Tests on optical fibres for the LHC machine

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Radiation Tests on optical fibres for the LHC machine T. Wijnands, D. Ricci CERN EN department Fraunhofer INT

  2. First radiation test on optical fibres December 2002 : First radiation test on SM and MM fibres • ~400 Gy total dose (SPS target area) • RIA : a few dB/km @ 400 Gy • Conclusion was : RIA is not an issue !

  3. Total dose test with 60Co source March 2005 : Verification of attenuation data with 60Co source: • 1310 nm and 1550 nm • Ge-P doped a-SiO2 fibres from Draka NK Cables Ltd manufactured using the MCVD (Modified Chemical Vapour Deposition) process _ Ge-doped a-SiO2 fibres from DrakaFibre Technology BV manufactured using the PCVD (Plasma Chemical Vapour Deposition) process

  4. Radiation Induced attenuation Ge-doped fibres Dose rate : 1 kGy per hour

  5. Radiation Induced attenuation Ge-doped fibres After annealing at room temperature

  6. LHC cleaning sections 2005 : Difficult situation in the LHC • Many SM optical fibres are passing through LHC cleaning sections • Dose rate is ~10 kGy/year • Maximum attenuation (BPM/BLM system) 7 dB/km • For Ge-doped fibres 7dB/km RIA corresponds to 600 Gy ! • LHC operational in 2007 ! Start of search for SM radiation hard optical fibres

  7. LHC cleaning sections 2005 : Difficult situation for fibres in the LHC ! • Many SM optical fibres are passing through LHC cleaning sections • Dose rate is ~10 kGy/year • Maximum attenuation (BPM/BLM system) 7 dB/km • For Ge-doped fibres 7dB/km RIA corresponds to 600 Gy ! • LHC operational in 2007 ! Start of search for SM radiation hard optical fibres for LHC

  8. T. Wijnands et al. TWEPP 2007 Prague

  9. Lessons learned • RIA is caused by TID • Test results in SPS (complex radiation field) near identical to 60Co. • Production process is very special • Small manufacturing changes may cause large variations in RIA • QA is crucial for the series production and includes sample testing • QA is crucial when you test on RIA (procedure, test setup , samples)

  10. M&O and new applications • How to address QA for small batches of radhardfibres ? • What fibres can be used for applications > 100 kGy ? • What if T = 5 Kelvin ? • What coating ? • How to achieve compatibility with blowing technique ? • Can we also find radhard MM fibres? • Can we use light at 850 nm ?

  11. Radiation test of SM Optical Fibres 25 January 2010 : 3 random samples from LHC series production : • RRSMFB 110A • RRSMFB 630A • RRSMFB 380A one sample from the 3 was selected for the test 11 February 2010 : Start of irradiation test up to 5 MGy: • 1310 nm and 1550 nm • Room temperature • Light power 10 mW • Dose rate 220 Gy/min 4 March 2010 : End of first irradiation test

More Related