DOFRS for NA/ECN3

Wednesday 15 Jun 2022, 15:30 → 17:00 Europe/Zurich

54/R-037 (CERN)

DOFRS for NA/ECN3 - 15 June 2022

Present: Y. Kadi/NA-CONS; M.Fraser, J. Bernhard; R. Garcia/R2E; D. Di Francesca, D. Ricci/EN-EL  

Point in bold below were the agenda of the meeting:

1- Understanding of the requirements for dose-monitoring in the areas from TCC2/TDC2 up to ECN3

NA-CONS confirms that DOFRS will be needed at term for dose monitoring (precise areas to be defined). D. Ricci: the baseline so far is to install the cable tray/tubes infrastructure during Phase 1 (LS3) in TDC2/TCC2, with an option to install also fibres and interrogators (to be confirmed upon preliminary studies on radiation levels).   

Concerning ECN3 ongoing studies, there is a need to assess the beam dynamics in P42 (i.e. the beam line spanning from TT83 to TCC8). That should be done in 2022-24 to serve as an input on how to optimise the beam line for the future physics experiments in ECN3.  Possible solutions were considered during the discussion, including:

1. Design and deployment of a DOFRS system (~700m ) during YETS 2022, including its operation (maintenance & data extraction) during the following years;
2. Deployment of BLMs during YETS 2022 along the beam line 
3. Placement of RPL passive dosimeters in strategical positions (during YETS 2022)
4. Deployment of RADMON/BATMON (possibly working via wireless or on battery)
5. Deployment of passive fibre sensors (reading them out with an OTDR during technical stops)
6. Deployment of -novel type- TIMEPIX BLMs (only a couple to cross-reference the other deployed sensors)

2- matching of the requirements with existing tools/methods/strategy/resources 

Solution (B) would be ideal but was a priori excluded, imagining the constraints for deploying and cabling all the BLMs

Solution (A) was hence identified as a more feasible option. Nonetheless, the following points are to be considered when analysing the details of its feasibility:

• The solution would imply installing a brand new DOFRS infrastructure in areas that are not targeted for the initial phase of consolidation (phase 1) but rather to be consolidated during NA-CONS phase2;
• DOFRS can detect a few Grays (with spatial resolution of meters/centimetres). Hence, it might be able to monitor the dose only for a few months (depending on the area), after which the fibres will have to be replaced. Additionally, the cable has to run on continuous cable trays (point not yet verified).
• Currently EN-EL has no fibres in stock for such an additional requests, plus the radiation resistant fibres necessary to transport the signal from the sensor to the interrogators, are currently all reserved for Hi-Lumi project (additional procurement of those fibres will only happen in 2024-25)
• The lead time for new fibre sensors will be minimum 6 months (3 months for sensor production + 3 months for special cabling manufacturing). The lead time for interrogators was in the past 2 years with a competitive tender, while buying only one with a gré-à-gré order is estimated to take up to 6 months, depending on the availability at the manufacturer of same-type instruments (as those bought in the past) and on requirements for software upgrades/adaptations;
• EN-EL resources are fully allocated for the year 2022 (YETS included). Target for realistic system delivery is YETS 2023-24.
• R2E-MCWG: guarantees the availability of resources for data processing and visualisation, once the system is deployed.

Solutions (C) (D) E) (F) can be instead exploited either singularly or in combination, entailing a reduced effort w.r.t. to (A) and (B), while offering valuable data for both ECN3 studies and DOFRS studies (aiming at future system deployment).

Preliminary conclusions and actions:

• Matthew+Ruben to study how the backup solutions (C, D, E, F) could be combined for extracting relevant data, waiting for DOFRS to be deployed in YETS 23-24. R2E/MCWG can deploy RPL and RADMON for monitoring in the short terms, upon request via Snow Ticketing. Evaluate if installation of 1or2 representative BLMs or TimePIX BLMs (new type) would be useful to cross-calibrate. Choose the type having a minimum impact on cabling.
• EN-EL to see if passive fibres could be deployed during YETS 2022-23, to be measured offline (during 2023 technical stops). To check in particular about leading time with manufactures and how to protect the fragile fibre;
• EN-EL to check to what extent the installation of DOFRS infrastructure (tubing) could be advanced during YETS 2022-23 in P42
• "P42" request was  inserted in PLAN so far under "PDC project"--> Yacine to check with Matthew if and how to regroup them under NA-CONS.

3- matching of the requirements with NA-CONS project strategy/resources, in particular w.r.t. Phase 1 and Phase 2 already targeted activities

Action Daniel/Diego+Yacine: to look into DOFRS needs at term for all NA-CONS areas. Confirm the objective for Phase 1 and pre-estimate activities for Phase 2. Propose priorities by areas, to cope with limited resources.

4- A.o.B

None.

Minutes taken by D. Ricci