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SUMMARY:Electrical Engineering Expert Group Kick-off
DTSTART:20261014T120000Z
DTEND:20261014T130000Z
DTSTAMP:20261105T013900Z
UID:indico-event-1736643@indico.cern.ch
DESCRIPTION:Speakers: Francesco Bianchi (Universita e INFN\, Perugia (IT))
 \, Lucas Hermida Peña (Einstein Telescope Organisation)\n\nRecording\nhtt
 ps://cern.zoom.us/rec/share/hg434PxZnvnLBjV1h2WcnE4rlI4pgEqGAeqvxx6td41Eba
 F0cPKh3BSet9uCTrGq.NxAj8qGpT83yJsez?from=hubPasscode: Wv=4%KNE\nMinutes: E
 lectrical Engineering Expert Group Kick-off\nDate: Wednesday 14 October 20
 26\, 14:00–15:00 (Europe/Zurich)Coordinators: Francesco Bianchi\, Lucas 
 Hermida PeñaPresent: Francesco Bianchi\, Lucas Hermida Peña\, Riccardo V
 asapollo (CERN)\, Flavio Nocera (EGO)\, Barbara Garaventa (INFN Genova)\, 
 Fiodor Sorrentino (INFN Genova)Apologies: Guido Visser (Nikhef)\n\n1. Intr
 oduction from the Coordinators\nLucas opened the inaugural meeting of the 
 Einstein Telescope (ET) Electrical Engineering Expert Group. It is one of 
 two Expert Groups now established\; the other covers Cooling & Ventilation
 . The group's purpose is to:\n\nsupport the evaluation and further develop
 ment of the electrical engineering work\,\nact as the interface between el
 ectrical engineering\, detector infrastructure and other ET systems\,\npro
 vide an ongoing forum for technical discussion and review.\n\nMeetings wil
 l not follow a fixed cadence. They will be called when there are open issu
 es\, decisions needing expert input\, or relevant developments from CERN. 
 Any member can propose a meeting in coordination with the coordinators.\nR
 iccardo Vasapollo announced that he will leave the project at the end of N
 ovember 2026. A new engineer will take over the electrical engineering wor
 k\, and a full handover is planned. The coordinators thanked Riccardo for 
 his contributions.\n2. Introduction from the Members of the Expert Group\n
 \nFlavio Nocera (EGO): Engineer with over 20 years in gravitational-wave i
 nstrumentation. He started on Virgo in the late 1990s\, worked on LIGO at 
 Caltech on design\, installation and commissioning\, and returned to Virgo
 /EGO in 2005. He has broad experience across most Virgo subsystems.\nBarba
 ra Garaventa (INFN Genova): Physicist. Her master's and PhD work was on sq
 ueezed light and quantum noise mitigation. Since 2023 she has worked on ma
 gnetic noise mitigation for ET. She is drafting guidelines on integrating 
 magnetic noise mitigation into ET infrastructure\, with a report due in No
 vember 2026.\n\n3. Technical Presentation on the Status of the Electrical 
 Engineering Deliverables\nSpeaker: Riccardo Vasapollo\nLoad survey\n\nLoad
  data is being collected from the relevant system contacts: ventilation an
 d clean rooms (Carlo\, CERN)\, cryogenics and towers (Lucas Hermida Peña\
 , Francesco Bianchi)\, suspensions (Patrick Werneke)\, and optics (via Luc
 as).\nLoads are grouped into three networks:\n\na Machine Network for tech
 nical systems\,\na General Services Network for lighting and ambient venti
 lation\,\na Safety Network for personnel safety and critical equipment.\n\
 n\nData maturity varies between systems. The aim is to freeze load values 
 by the end of 2026.\nIn the triangular configuration\, the corner stations
  carry the highest loads. Bakeout produces peaks of around 500 kW along th
 e arms\, which makes long-distance supply difficult.\nIndicative peak load
 s:\n\nMachine Network: several MW\,\nGeneral Services: about 20 MW in tota
 l\,\nSafety Network: minimal\, with a modest increase expected.\n\n\n\nSys
 tem design\n\nThe medium-voltage network design is a coupled problem. Subs
 tation locations\, backbone architecture\, equipment sizing and space dema
 nds all depend on each other.\nTunnel space is the main bottleneck. Three 
 layout options were presented:\n\nthe current baseline\, with caverns ever
 y 5 km and only two shafts\,\nalcoves about every 1 km for distributed sub
 stations\,\na combination of the two.\n\n\nUninterrupted low-voltage distr
 ibution over 5 km is not feasible under standard industrial practice. The 
 cable trays required would be impractically large and unsafe to maintain u
 nderground.\nA technical gallery concept was proposed to reserve space for
  cable trays. It is inspired by the LHC false floor and fixed scaffolding.
 \nThe study is moving from conceptual to preliminary design. To produce si
 ngle-line diagrams and a Class 3–5 cost estimate\, ETO must decide on sp
 ace allocation and substation placement: alcoves\, additional shafts or a 
 technical gallery.\n\n4. Discussion\nScope: triangle vs. 2LThe current CER
 N–ETO mandate covers the triangular configuration only\, since it is the
  most complex. Solutions are expected to transfer to the 2L configuration 
 by removing about one third of the systems. The scope may be revisited in 
 the future.\nDependence on the civil infrastructure baselineFiodor Sorrent
 ino noted that many electrical requirements are driven by civil infrastruc
 ture choices that remain undefined. Riccardo confirmed that substation pla
 cement and cable routing cannot be properly assessed without these inputs.
  Progress on key design decisions therefore depends on a civil infrastruct
 ure baseline.\nMagnetic noise mitigation\n\nBarbara requested that magneti
 c emission KPIs be included in the study. Choices such as substation spaci
 ng (5 km vs. 1 km) will strongly affect noise levels near sensitive detect
 or areas.\nShe proposed a joint zoning strategy that places transformers\,
  switchboards and racks as far as possible from the interferometer.\nRicca
 rdo agreed. He noted that emissions depend on distance\, cable type\, shie
 lding and voltage level\, and that noisy equipment should be grouped in de
 dicated electrical rooms. Moving these rooms further away increases cablin
 g cost\, so the trade-off is again coupled to civil infrastructure.\nRicca
 rdo proposed involving CERN's cabling section\, which has expertise in cab
 le emissions\, to review Barbara's report.\n\nPower backup strategy (UPS a
 nd generators)\n\nLucas asked which systems must remain powered during an 
 outage.\nFiodor noted that in current detectors\, UPS covers most hardware
  needed for locked operation\, while initial vacuum pumping may not need i
 t.\nFlavio compared the two existing detectors:\n\nVirgo has broad UPS cov
 erage\,\nLIGO historically covered only vacuum and accepted operational do
 wntime as long as safety was maintained.\n\n\nRiccardo observed that Virgo
 's backup capacity is two to three times its needs\, and that ET's load is
  about ten times larger. He proposed a selective approach: UPS for critica
 l subsystems (about 40% of load)\, bridging to generators\, and no blanket
  UPS coverage.\nFiodor agreed this is reasonable. The final strategy is a 
 decision above the scope of the current study.\nFormal power quality and r
 eliability requirements\, such as limits on harmonics and availability tar
 gets\, have not yet been received.\n\n\nAction Items\n\n\n\n#\nAction\nOwn
 er\nDue\n\n\n\n\n1\nCirculate the magnetic noise mitigation guidelines rep
 ort to the Expert Group for feedback\nB. Garaventa\nNov 2026\n\n\n2\nAsk C
 ERN's cabling section to review the magnetic noise report\nR. Vasapollo\nN
 ov 2026\n\n\n3\nInclude magnetic emission KPIs in the electrical infrastru
 cture study\nR. Vasapollo / successor\nOngoing\n\n\n4\nFreeze load survey 
 values\nR. Vasapollo / successor\nEnd 2026\n\n\n5\nBring the tunnel space 
 allocation decision (alcoves / shafts / technical gallery) to ETO\nL. Herm
 ida Peña\nTBD\n\n\n6\nCollect formal power quality and reliability requir
 ements\nCoordinators\nTBD\n\n\n7\nOrganise the handover to Riccardo's succ
 essor\nL. Hermida Peña\nEnd Nov 2026\n\n\n\n \n\nhttps://indico.cern.ch/
 event/1736643/
URL:https://indico.cern.ch/event/1736643/
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