SLHC Radiation Test Results Preliminary measurements Versatile Link project from exposure to gamma rays at SCK-CEN B. Todd Huffman (speaker), J. Hanzlik, C. Issever, T. Weidberg 24/09/09 B. Todd Huffman

The Outline Brief explanation of facility used SCK-CEN sources Test procedures then and now. Some Previous results and motivation for temperature controlled tests Tests of Mulit-mode fibres Draka RHP-1 SRH InfinicorSX+ Conclusions 24/09/09 B. Todd Huffman

The two locations: 60Co g rays RITA 0.6kGy/hr BRIGITTE 20kGy/hr 24/09/09 B. Todd Huffman

Previous High-dose test result Draka Commercial Draka 3 Infinicor Draka RHP-1 SRH 24/09/09 B. Todd Huffman

These Results are Good Good Candidate MM fibres identified InfinicorSX+ and Draka RHP-1 Draka Fibre is under further development and will require future tests But Limitations of Previous tests have prompted further studies. Temperature dependence in particular 24/09/09 B. Todd Huffman

RIA and temperature, 1st 6 hours. 24/09/09 B. Todd Huffman 7

Previous research on RIA in fibre Single-mode Multi-mode 850 nm GRIN fibre at room temp (curve C) and -17 C (curves A & B) credit: Thériault Radiation effects on COTS laser-optimized graded-index multimode fibers exposed to intense gamma radiation fields Single-mode RIA as fcn of temp. credit: Kanamori et al. Transmission Characteristics and Reliability of Pure Silica-Core Single-Mode Fibers RIA is temperature-dependent! 24/09/09 B. Todd Huffman 8

Cold Container designed Uses Peltier cooling elements 4 coolers – 15V and 7A operation Direct connection to Draka fibre DT = ~60 deg C Able to remove ~40W heat load Suitable only for low dose facility Radiation Damage and heat load Heat shed to the shielding water Water ambient temp = 30 deg C. Goal  Maintain -250C 24/09/09 B. Todd Huffman

Container to Actively Cool Fibres 24/09/09 B. Todd Huffman

InfinicorSX+ Temperature Effects 24/09/09 B. Todd Huffman

Draka Fibre Temperature Effects 24/09/09 B. Todd Huffman

An interesting Temp. Radiation effect Prior to radiation, fibre attenuation relatively insensitive to temperature variations. RIA sensitizes fibres to temperature. Particularly Dramatic with Infinicor fibres Present, but less of an effect with Draka fibres Keep in mind 50m of fibre are used. 24/09/09 B. Todd Huffman

Before 0.01 dB 0.05 Deg. C 24/09/09 B. Todd Huffman

after 0.7 dB 0.05 Deg. C 24/09/09 B. Todd Huffman

0.05 dB Before 1 Deg. C 24/09/09 B. Todd Huffman

after 0.2 dB 1 Deg. C 24/09/09 B. Todd Huffman

Comparisons, InfinicorSX+ T = +300 C Dose = 65 kGy(Si) Gamma source at room temperature. Variation is from prev. Stability limitations. T = -23.30 C Dose = 30 kGy(Si) 24/09/09 B. Todd Huffman

Comparisons, InfinicorSX+ T = +300 C Dose = 65 kGy(Si) Gamma source at room temperature. Variation is from prev. Stability limitations. T = -23.30 C Dose = 30 kGy(Si) 24/09/09 B. Todd Huffman

Draka RHP-1 SRH fibre T = -40 C Total Dose ~ 15 kGy(Si) T = -250 C 24/09/09 B. Todd Huffman

Attenuation Upper limits Low doses  extrapolate linearly up to SLHC tracker doses 375kGy. CAUTION!!: upper limit Lower dose rate in Tracker volume RIA follows logarithmic scale at high dose At -250C inside Tracker volume InfinicorSX+  1.1 dB Warm result  0.24 dB Draka RHP-1  0.6 dB 24/09/09 B. Todd Huffman

Conclusions Infinicor Fibre is Ge doped Draka Fibre is F doped No Ge used Neither uses Phosphorous in their manufacturing process F doped fibre (Draka) has better radiation performance even at cold temperatures ~0.05 dB/m vs. ~0.08 dB/m after 30kGy integrated exposure. 24/09/09 B. Todd Huffman

Conclusions Are we Qualified for operation of these fibres at Cold Temperatures? Definite Maybe. Extrapolation very conservative, but very dodgy Ideally we would obtain close to a full SLHC dose (~400kGy) cold Brigitte can do this Smaller volume. Potentially higher heat load. Peltier system would surely fail. 24/09/09 B. Todd Huffman

Conclusions We believe a CO2 thermal management system can achieve the same goal at the higher dose facility. Studying the feasibility of this. Back-up is to use dry-ice. Previous tests show we obtain -780C for 24 hours even with heat load. But, such a test would teach us little if fibre ends up with more than 1dB/m RIA. 24/09/09 B. Todd Huffman

General future Cold tests finished by April Qualified two fibres Re-qualify Draka fibre with higher bandwidth Move to qualifications of PLC splitters, LC connectors, full cabling solutions Mechanical tests 24/09/09 B. Todd Huffman

Next Slides are backup slides End Of Talk Next Slides are backup slides 24/09/09 B. Todd Huffman

Optical Patch cables Splitter No Longer used! Conn. 24/09/09 B. Todd Huffman

System Stability tests – last year Ran system for extended time periods. Found stability limitations Extensive tests by J. Hanzlik showed the optical splitter was the main cause of instability. ±1.5 dB absolute stability limitation for MM fibres. 24/09/09 B. Todd Huffman

Stability of test system Output from multi-mode fibre (coupler in system) VCSEL coupler PD PD = photo-diode 1.5 dB 0.2 = connector Output from multi-mode fibre (no coupler in system) -.11 VCSEL PD dB -.15 PD = photo-diode = connector Removing coupler seems to improve stability of MM system 24/09/09 B. Todd Huffman 12

Stability by the Numbers Multi-mode fibre InfinicorSX+ RMS variation using 1x4 optical splitter ~0.15 dB RMS variation of single channel – no splitter ~0.0053 dB Single Mode fibre SMF-28 RMS variation using 1x4 optical splitter ~0.014 dB RMS variation of Single channel ~0.042 dB 24/09/09 B. Todd Huffman

You can even watch it turn on. RIA oscillations increase in amplitude Temp. oscillates & rad. starts 24/09/09 B. Todd Huffman

Semi-cold Draka Run -4 deg C 24/09/09 B. Todd Huffman

Behavior of Reference fibres Attenuation, dB Attenuation, dB 24/09/09 B. Todd Huffman

InfinicorSX+ Temperature Effects 24/09/09 B. Todd Huffman

Draka RHP-1 SRH fibre T = -40 C T = -250 C 24/09/09 B. Todd Huffman