Forward physics pertinent ECRs Mike Lamont, Samy Chemli

Forward physics ECRs TitleEDMSWhenStatus Temporary Installation of LHCb Scintillating Fibre Tracker Test-Beam Module in RB84 LHC-X8FC-EC-0002TS3Approved Optical Fibres & High Voltage Cables for the CMS ZDC Upgrade LHC-X5ZDC-EC-0002TS2Approved Change of Powering for Q4 in IR1LHC-LJ-EC-0044YETSApproved CT-PPS Timing & tracking detectors in horizontal Roman Pots (for standard optics) LHC-XRP-EC-0012YETS TOTEM Timing detectors in vertical Roman Pots (for high beta*) LHC-XRP-EC-xxxxTS3 Installation of the ATLAS/AFP stations, Phase-1 LHC-XAFP-EC-0002YETSApproved

CMS ZDCs – fibres and cables Optical Fibres & High Voltage Cables – Approved and good to go… – powering permit issue discussed at last LMC – “moving slightly the BRAN by a few centimetres”? For info, there will be a remote camera system to operate the crane above the TAN remotely (see EDMS LHC-HXTC-OP-0001). – Samy: This document is still under approval and I just intended to inform the LMC when released. – Nothing more than informing, but I still have 6 or 7 documents still pending with Michael Murray.

ECR Under Approval LHC-X5ZDC-EC-0002 Version 0.2 → Installing Optical Fibres & High Voltage Cables for the CMS ZDC Upgrade S. Chemli for EN-MEF-DC4 A few questions from EN-EL to be answered

Change of Powering for Q4 in IR1 Freddy: – budget code assigned to cover the cost of cables for the dual powering of the Q4s in IP1 for ATLAS- ALFA (LMC 224) Space reserved for Q4 (but not Q8, Q7, Q10) Status of procurement?

TOTEM timing detectors TOTEM Timing detectors in vertical Roman Pots (for high beta*) – a) TOTEM picosecond clock distribution – b) Timing detectors – c) Services for the different subcomponents (HV, LV, cooling, services, etc.) At present it looks promising, that we can install the first components during the TS3 in 2015, to be still tested with the LHC during – We try to provide the TOTEM ECR by mid September Joachim Baechler

CT-PPS Timing & tracking detectors CT-PPS Timing & tracking detectors in horizontal Roman Pots (for standard optics) – a) CT-PPS reference timing system – b) CT-PPS timing detectors – c) CT-PPS tracking detector – d) Services for the different subcomponents (HV, LV, cooling, services, etc.) In this sense we can already now discuss the issues related to the laying of the cable for the CT-PPS clock distribution before the final ECR is ready. (contact company to give cost estimate and time line). At the present state I do not see components for the CT-PPS project to be installed in The installation work could start in the end of year shut down We try to provide the ECR by October Joachim Baechler

CT-PPS Timing & tracking detectors The CMS-TOTEM Precision Proton Spectrometer (CT-PPS) [1] project proposes to install a reference timing system in the second half of 2015, with an electronics module at +215 m from IP5 and another electronics module at -215 m from IP5. There will also be a power supply for each electronics module. In addition, a coaxial cable connecting the two modules needs to be installed and will be laid through the bypass tunnel. Details of theelectronics modules, power supplies, and coaxial cable are given. The lifetime of this upgrade project is foreseen to last until LS3.

TOTEM – CT-PPS What does the Totem team intends- to do during TS3 and the YETS? Two parallel options for different optics to give the timing - which has the priority? Need to give proper instructions to the people installing the cable – they don’t know what to order for the YETS… One of the ECRs I have since April and still not the green light to launch it. Samy Chemli

AFP

AFP discussion 1/3 Experience from TOTEM/ALFA in 2015 – Looking good so far – UFOs on 1 ALFA pot – ferrite? Ferrites – Buy the right ferrite – “it’s the way they cut it” – Reference Giuseppe and Fritz – AFP need lead time – MR will look into it NB 2.5 mm gap to bellows 20 th July 2015: Michael Rijssenbeek, Benoit Salvant, ML

AFP discussion 2/3 Heating with beam – In parking with 1200 bunches at 450 GeV – some heating already observed – Cooling has to be verified Copper coating on bottom of pot – is it feasible? – Would reduce resistive wall heating. – ALFA isn’t, TOTEM isn’t (technical problems) – If not there then possibly faced issues from beam induced heating if aiming to be qualified for Run 3/HL-LHC – Run 3 – could be intensity limits – even in parking (worry about this particularly) NEG coating – Parts of assembly but not pots themselves – again this could imply constraints – check with e-cloud team

AFP discussion 3/3 RF shields inside bellows and connections Window (30 mm diameter) – Quartz viewpoint for calibration of pot in lab – To be removed before operation, replace with blank flange Cu O ring – detailed drawing available – “fine tuning” All pots checked in lab for non-conformities Impedance – Measure prototype early Oct. – Production pots – measure in November to validate

Follow-up by Michael Rijssenbeek Copper coating of the flat part of the AFP Roman pot bottom (area around the thin window facing the LHC beam). This will improve the RF behavior of the Roman pot. See the attached figure, where the proposed coating area is bounded by red lines. The thickness must be about 10 um. Questions: – Who would do this? How much lead time is required? How much time is involved with the coating procedure itself? – Solution: 5 microns (doable with with sputtering) would still help a lot RF-wise and would be much easier than doing the galvanic bath (Benoit et al) NEG coating of the interior beam chamber extensions of the Roman pot station central vacuum assembly (see attached figure, where the areas to be NEG-coated are delineated in red)). This will improve the primary vacuum. Questions: – Who would do this? How much lead time is required? How much time is involved with the coating procedure itself? – How stable is the coating? Does it scratch and flake-off easily? Ferrites for RF absorption. I understand from Benoit that very recently ferrites TT2-111R by Trans-TechInc.com, USA, with a very much improved fabrication procedure were measured to have excellent UHV behaviour without having to fire them at 1000 C for an extended amount of time. Questions: – Do you have more details of this latest development and measurement? – The AFP ferrites, see also the attached drawing, are identical in dimensions to those used for ALFA. We need to order these ferrites for AFP very soon and I would appreciate purchase information (DAI copy, Lead time, bake-out information if so needed).

Ferrites For information, the “new ferrites” are still the same TT R. – Only the machining process at the end of fabrication is being changed since it has been suspected for some time that it could be responsible of the bad vacuum behaviour of these ferrites (without high temperature firing). If the new process is validated, the impedance team recommends that it should be implemented as soon as possible for any new TT2-111-R ferrite that is installed in the machine. – It is clear that it may be too late for the 2 AFP Roman pots planned to be installed during this YETS, but it should not be too late for the second batch of pots that are planned to be installed in the EYETS. Benoit Salvant

NEG - Mauro Taborelli To question B: What do you mean with primary vacuum? Which pressure do you have there? I was supposing it is in the beam vacuum We can do it, if it is accurately planned the coating itself is roughly one week including mounting and dismounting (and some margin), but for this we need to have all the cathodes and extensions for vacuum ready. It should be planned well in advance. You must also consider that the part must be first cleaned in the cleaning workshop and it is not easy and safe to clean edge welded bellows; we will do it at best. Do you want the coating only in that region? We probably need some masking again, it is easy, but it needs some mechanics. There are 7 km of coating in the LHC.....hopefully it is stable J. As any coating if you scratch sufficiently hard it will come off, but you are not supposed to scratch right?