Consolidation and development of the CERN radiating cable infrastructure in PS and TT2 F. Chapron IT/CS

Agenda What is the use of the radiating cable at CERN ? What needs to be done and how ? Work in PS Work in TT2

What is the use of the radiating cable at CERN ? More than 50 km of cable at CERN Almost all tunnels and experiments Used to carry multiple signals CERN safety services: TETRA signals used mainly by the CERN fire brigade. Indoor localisation system (indirectly) External safety services: the TETRAPOL signals from the Swiss and French safety organisations General public mobile services: GSM (2G), UMTS (3G) and LTE (4G) signals Special users like the TIM (“Train d’Inspection sur Monorail”) or remote maintenance robots access CERN intranet via a secured and controlled access (CERN APN). Radiating cable TI8 injection tunnel

What needs to be done and how ? Due to the aging of the cable and the high exposure to radiation in some locations, the infrastructure must be renewed before it stops working. If the radiating cable is broken, mobile communications are not possible anymore A global PLAN project (number 10046) was created for the approval process, but it is including many sub-projects which will be described in specific ECRs To allow a smooth transition (without cutting the mobile and radio services) : Deployment of a new cable during E-YETS, YETS and LS2 Replacement of the existing cable during LS3 Who does what ? IT-CS: inputs for coordination, material supplying, ECRs drafting (with EN/EL and EN/ACE), cable connectors and terminations, commissioning EN-EL: coordination and supervision of cable pulling Where and when? E-YETS: PS and TT2 (first ECRs already circulated for approval) YETS: Booster LS2: SPS, LHC3/LHC7 and aside the LHC experiments (at collimator locations) Schedule for other locations (Linac, CTF2,3, AD, ISR, Ntof) to be evaluated

Work in PS during E-YETS ECR number 1705458 v.0.1 Status: under approval (submitted beginning of July) Few comments but no blocking point. The ECR to be updated. Extension of coverage in PS cross galleries Currently there is no mobile coverage in the PS cross galleries A New TETRA emitter will be placed in 359/R-009 A coax cable will be pulled from 359/R-009 to a radio frequency splitter in room 353/S-202 (location to be identified) Pulling of a radiating cable in each of the four PS cross galleries Placed on the ceiling displaced from the middle to preserve the reservation for the line of sight SURVEY Stopping just before the fire protection doors Cross of the fire door at the end of tunnel 1 Addition of a cable in PS ring Attach, with clamps, a second cable above the internal yellow girder (from ring centre), similar to the installation of the existing cable on the external yellow girder. To cross the eight (8m) sections where there are (CV) pipes by connecting radiating cable segments by a flexible, small diameter coax cable. 3D integration still to be done

Courtesy to P. Lelong for the drawing

Work in PS during E-YETS Constraints When pulling the cable the path will be blocked In PS cross tunnel, the cable pulling requires one week of work for each tunnel In PS ring, the cable pulling requires one week of work for each of the eight section Pulling of a small coax cable from emitter in 361-3-411 to the PS (via cable trays). Radiations at some places Junction between TT2 and PS ….

Work in TT2 during E-YETS ECR number 1706376 v.0.1 Status: under approval (submitted beginning of July) Few comments but no blocking point. The ECR to be updated. Addition of a radiating cable Interconnected with the PS ring infrastructure Extension of infrastructure up to lift in building 269 (A-TT2-E location) The second cable will follow the same path and as much as possible, at a distance of 30 cm from the existing cable At the end of TT2 tunnel, the cable will be split to cover TTL2 tunnel Extension of coverage in the safety exit (ladder) in TTL2 with antenna

Work in TT2 during E-YETS Cable path in details

Work in TT2 during E-YETS Cable path in details

Work in TT2 during E-YETS Constraints One fire door to cross When pulling the cable the path will be blocked. The work will last up to 1 month Known co-activity with the renewal of fire detection system Sorted out…

Thanks

Current radiation studies Since May 2016, new radiation tests are being performed on the “new” LF cable in CHARM in “operational mode” Objective: Identify any impact on “live” signals when the cumulative radiation dose increases Redo mechanical tests with a thinner accuracy than the previous tests Test the resistance of the clamps to radiation.

What is a radiating cable? Is a cable used to carry radio signals in buildings It’s like a “long” antenna connected to an emitter. It is made of two coax cables isolated by foam and protected by a jacket. Made for certain frequencies with better longitudinal loss (-3dB/m) and coupling loss The external coax cable has holes equally distributed all along which allow to broadcast the signal in a “clean” way Typically affix to the wall/cable trays with clamps At CERN, there 4 types of cables with their respective clamps CQG50 : installed in 2002/2003 mainly in LHC and SPS CQA50, CQB50, CQD50: installed in 1996 mainly in injector chain. Holes Foam Longitudinal loss Coupling loss Jacket Coax cables

What is the issue ? Picture in SPS1 Mechanical tests have been performed in 2010 on samples (jacket + foam) after radiation EDMS doc: 1077149 v.1 For samples exposed to more than 100 kGy, the foam starts crumbling away with low compression. If the LF cable is manipulated, there is a high risk of short-cut preventing normal LF operation Any repair will introduce additional power loss The foam losing its dielectric feature, first the longitudinal loss value of the cable will degrade (problematic for LHC), and the then coupling loss The external jacket also gets “burned” Radiation effects on other components was not tested (connectors, clamps) Normal aging of the cable Thirty (30) years under normal environmental in-tunnel conditions External damages Severe event like a fire destroying the cable can prevent communications in large tunnel sections Local damage (cable hit by “machines”) Local repair can be performed but will affect the max propagation distance 100 KGy Foam radiation tests Picture in SPS1

Work in PS during E-YETS Integration of the cable in PS cross galleries View from ring centre with tunnel 5 on the left and tunnel 7 in front. View from ring centre with tunnel 3 on the left and tunnel 7 on the right. View from ring centre with tunnel 3 on the left and tunnel 7 on the right. Tunnel 1 on the right and tunnel 5 in front.

Other topics Frequencies Materiel supply Commissioning Already broadcasted in all PS and TT2 (except extensions) Safety signals TETRA: Duplex frequencies: 425.4625/415.4625 MHz ; 427.3875/417.3875 MHz ; 425.9875/415.9875 MHz ; 427.0125/417.0125 MHz ; 425.0875/415.0875 MHz 425.2875/415.2875 MHz Simplex frequency: 406.1125 MHz, 406.2375 MHz, 429.2375 MHz TETRAPOL: French safety network: 383.425/393.425 MHz Swiss safety network: 384.095/394.095 MHz Public mobile signals GSM: from 876 MHz to 959 MHz UMTS: from 876 MHz to 959 MHz LTE: from 791 MHz to 862 MHz Materiel supply New cable for which radiation resistance is being tested in CHARM Commissioning Ejection of a signal with frequency generator and validation that propagation with RF analyser Interconnection with TETRA and mobile emitters (short disruption)

Conclusion The radiating cable infrastructure is the only means to have mobile communications in tunnels for the fire brigade and standard users The work in PS and TT2 will be done without service cut for end-users during the E-YETS The main constraint is the blocking of paths when pulling the cable