Meeting with TUM 04/21/23 P. Petagna – LHC Detector Upgrades: Cooling

Visit of the President of the Munich Technical University

LHC DETECTOR UPGRADES: COOLINGPaolo Petagna (CERN PH/DT)

• The Present ATLAS and CMS Trackers• Upgrade Challenges in Mechanical Engineering• Detector Cooling Peculiarities• Main R&D Issues on Cooling

Meeting with TUM 04/21/23 P. Petagna – LHC Detector Upgrades: Cooling

ATLAS INNER DETECTOR:TRT -> Gas detectorSCT -> 4088 Si modules (~3.3 M channels)PIX -> 1748 Modules (~80 M channels)

2,4

m

End Caps – TEC (at the two ends, one shown only)

Inner Barrel & Disks

- TIB & TID -

Outer Barrel - TOB -

Pixel detector

COOLING: LIQUID C6F14 (~50 kW)

TRT COOLING: LIQUID C6F14 (~60 kW)SCT/PIX COOLING: EVAPORATIVE C3F8 (~60 kW)

The Present ATLAS and CMS Trackers

6 m

2,3

m

6 m

7 m

TRT Barrel

TRT End Caps

SCT Barrel

SCT End CapsPixel

CMS TRACKER:Si-Strip TK -> 15232 Si modules (~9.6 M channels)

210 m2 Silicon sensorsPix TK -> ~1800 Modules (~60 M channels)

1 m2 Silicon sensors

Meeting with TUM 04/21/23 P. Petagna – LHC Detector Upgrades: Cooling

LHC @ 2013-14 -> ATLAS & CMS upgrade « phase I »: upgrade PIX systemsEnhanced electronicsReduced power consumptionMinimized radiation lenght (~ mass)Lower temperatureEnhanced cooling perfromance

LHC -> SLHC (2017-18?) -> Complete upgrade of the ATLAS & CMS Trackers (« phase II »)10 – 20 x track density : increase granularity10 x irradiation level : decrease temperatureReduce material budget : minimze power densities

optimize / stanadradize (layout)Enhance cooling performance

Upgrade Challenges in Mechanical Engineering

Meeting with TUM 04/21/23 P. Petagna – LHC Detector Upgrades: Cooling

PLC

Experimental Cavern Service Cavern

Chilled water+12°C

Chilled water+6°C

USC55 - CV zone

Tunnel~ 150 m

TT

TT

Detectorcooling unit

(C6F14)

Chiller group(R507 A)

Brine group

TT

UXC55 - 1st floor balconies

Detector Cooling Peculiarities I: Long Distance

Experimental Cavern Service Cavern<- 100 -150 m -><- 100 -150 m ->

<- 30 -50 m ->

<- 30 -50 m ->

ATLAS INNER DETECTOR COOLING PLANT:(simplified scheme)

CMS TRACKER COOLING PLANT:(simplified scheme)

Note: whatever stays in the Experimental Cavern must be- radiation tolerant- magnetic field tolerant

Meeting with TUM 04/21/23 P. Petagna – LHC Detector Upgrades: Cooling

Detector Cooling Peculiarities II: System Complexity

CMS TK cooling lines at/from distribution rack

Arrival/departure of ATLAS ID services inside the experiment

Meeting with TUM 04/21/23 P. Petagna – LHC Detector Upgrades: Cooling

Detector Cooling Peculiarities III: Geometrical Complexity and Mass Minimization

Layout optimization for physics rules, cooling adapts (up to wich level?)

Space optimization and need for “transparency”Impose minimization of pipe diameters and wall thickness

Different geometrical arrangements require very different local thermal management solutions

Meeting with TUM 04/21/23 P. Petagna – LHC Detector Upgrades: Cooling

• Thermal contacts and joining techniques

• High thermal conductivity materials

• Pipe materials, joining and connections

• Leak measurements

• In-situ leak repair

• Instrumentation & diagnostic tooling

• Thermal modelling

• … more !?

R&D Issues on Cooling I

Meeting with TUM 04/21/23 P. Petagna – LHC Detector Upgrades: Cooling

Extremely good thermal propertiesNon toxic / Non aggressiveCheapLong-term availableEnvironmental friendlyPoorly activated

R&D Issues on Cooling II

Choice of cooling strategy for upgrades

LIQUID Perfluorocarbon (CnF2n+2)

EVAPORATIVE

Perfluorocarbon (CnF2n+2)

Other refrigerant (or mixture)

CO2

Meeting with TUM 04/21/23 P. Petagna – LHC Detector Upgrades: Cooling

Extremely poor forecast possibility exists today for HIGH PRESSURE two-phase flows: even the most recent and successful models, like the “3-zones model” proposed by Consolini and Thome, providing relatively good forecast for HTC and p of low pressure refrigerants, performs rather poorly on CO2 and other refrigerant at high pressure. Experimental data are missing, in particular in “mini-channels” and in long channels of large cross section.

A R&D collaboration is presently being organized between CERN (CRYOLAB and PH Dept.) and external partners. At the moment

these include EPFL and University of Esslingen

R&D Issues on Cooling III

Physics of High-Pressure Two-Phase Flows

Meeting with TUM 04/21/23 P. Petagna – LHC Detector Upgrades: Cooling

R&D Issues on Cooling IV

Planned to have a standardized complete design (including controls) of a reproducible CO2 cooling unit (say around 2 kW refrigerating power) in 1-2 years from now to be used as standard test unit for all partners and as scalable prototype for upgrade installation.

•Choice of the best suited thermodynamic cycle•Choice of the components•“Rackability”•Reliability•Control strategy

CERN (PH Dept, Cryolab, EN Dept)NIKHEF (Amsterdam)SLAC (Berkeley)FNAL (Chicago)…OTHERS?

Meeting with TUM 04/21/23 P. Petagna – LHC Detector Upgrades: Cooling

Process modeling and dynamic simulation(Collaboration with Université Joseph Fourier Grenoble)

R&D Issues on Cooling V

Provide a basic model to study the steady state design• Component tests and Prototype

– Process: operating points, behavior, geometry study– Simulation steps

• Optimization of the components by data taking on the prototype• Improved off-line model design

Provide a reliable model to study the dynamic performances and risks• Control system design

– Process: PLC and SCADA deployment, control logic production– Simulation steps

• Virtual commissioning of the whole control system Ensure the quality of the source code before its implementation on the real plant• Commissioning and operation

– Process: validate the plant before its long-term operation– Simulation steps:

• Model calibration and Operator training• Development of operation facilities (decision, troubleshooting, diagnostics, control, …)

Improve the performances and the reliability of the control system, Improve efficiency in front of unforeseen situation understanding