EuCARD-2 is co-funded by the partners and the European Commission under Capacities 7th Framework Programme, Grant Agreement 312453

High Efficiency Work in Context

Erk Jensen, CERN

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• Our mandate: Prepare technology for the post-LHC era!

The raison d’etre

From council/en/EuropeanStrategy/esc-e-106.pdf:To stay at the forefront of particle physics, Europe needs to be in a position to propose an ambitious post-LHC accelerator project at CERN by the time of the next Strategy update […] CERN should undertake design studies for accelerator projects in a global context, with emphasis on proton-proton and electron-positron high-energy frontier machines. These design studies should be coupled to a vigorous accelerator R&D programme, including high-field magnets and high-gradient accelerating structures, in collaboration with national institutes, laboratories and universities worldwide.

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• Our mandate: Prepare technology for the post-LHC era!

• Economic use of energy resources mandatory!

EnEfficient RF Sources, The Cockcroft Institute, 3-4 June 2014

The context

• B. Vierkorn-Rudolph at Workshop Energy for Sustainable Science, ESS 2011: All future (large) accelerators must consider energy efficiency!

• If we don’t conceive them for sustainable energy consumption, these projects will not be approved!

• Larger overall efficiency means less consumption and less waste heat production (smaller carbon footprint)!

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• Our mandate: Prepare technology for the post-LHC era!

• Economic use of energy resources mandatory!• Societal benefits

The context

From the Executive Summary of the 1st ESS workshop: Large Scale research infrastructures are able to generate very innovative solutions that can be used profitably elsewhere and be at the base of win/win partnerships with industries through a smart specialization approach.

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The challenge of energy efficiency and its impact on the environment have been clearly assessed as well as the increase of efficiency as a major contributor in limiting CO2 emissions. Moreover, new ways of renewable energy supply schemes for existing or future planned RIs should be explored as technologies become more and more competitive. Several main action lines of development have been identified:• Reduction of primary electricity consumption through increased efficiency,• […]• Better usage of waste heat by recovery and valorisation schemes,• Exploiting RIs as test bed for novel developments and technological

demonstrators,• Exploring renewable energy solutions for existing and future RIs,

EnEfficient RF Sources, The Cockcroft Institute, 3-4 June 2014

Conclusions of

http://europeanspallationsource.se/energyworkshop

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Present CERN consumption

To get a feel for the scale …

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Synergies between projectsHL-LHC HE-LHC LHiC NICA RHIC II FAIR LHeC eRHIC ELIC Super

KEKBSuperB ILC CLIC PFWA

LWFADielec-tric Acc

Muon Collider

Neutrin Factory

Project X

Coordination CERN CERN CERN DUBNA BNL GSI CERN BNL JLAB KEK LNF GDE CLIC collSLAC/LBL SLAC? MAP NF Coll FNALElectron cloud Cornell? CESR-TA X X X X X X X X X X XSC magnets (High Field, Fast Cycling, Super-Ferric, Wigglers)

Magnet R&D network?

CERN, FNAL, GSI HF HF/FC HF SF FC HF HF W

Super-Conducting RF TESLA Tech coll?FLASH, NML, STF, XFEL X X X X X X XHigh field NC Structures ? CTF3, SLAC, KEK X XLow emittance generation CLIC/ILC WG? ATF1 X X X X X XNanometer beam focusing ATF coll ATF2 X X X X X X XAlignment and stabilisation ? AlignTF, StabTF X X X X X X X X XRF power source high efficiency ? X X X X X X XHigh beam power generation&handling ? SNS, PSI X X X X X X X X X X XCollimation & targets high power beams ? HRad,HARP,MERIT X X X X X X X X X XCooling (Electron, Coherent, Stochastic) ? RHIC S,E S C C EIonisation cooling ? MICE,MTA, MuCool X Xcrab cavities ? KEKB X X X X X XPlasmas LBL, SLAC BELLA, FACET XLasers LBL, Ec. Polyt BELLA, LULI X X X XDrive beam generation CTF3 collab CTF3, FACET X X XBeam dynamics simuations ? Test benches X X X X X X X X X X X X X X X X X XBeam Instrumentation ? X X X X X X X X X X X X X X X X X XBeam based feedbacks ? X X X X X X X XEnergy recovery linacs CEBAF? CEBAF, BNL R&D ERL X X XNanobeam scheme (LPA & Crab waist) B Fact collab? DAFNE X X XPositron generation ? X X X X X XPolarisation ? X X X X X X X XDynamic vacuum ? X X X X X X X X X

Muons & NeutrinosR&D/Projects

Test Facilities

Protons Ions Electron-Hadrons B Factories Linear Colliders

Taken from:J.-P. Delahaye, “New Accelerator

Projects”,ICHEP10, 22.-28, July 2010, Paris

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Future Multi-MW machines

IFMIF ESS SPL II ILC .5 TeV CLIC 3 TeV

Frequency 175 MHz 704 MHz 704 MHz 1300 MHz 1000 MHz

Technology Grid tubes klystrons klystrons MBK MBK

Total AC power 38 MW 40 MW 230 MW 415 MW

Modulator output 60 MW 17.8 MW 26.5 MW 135 MW 255 MW

Power source output 25 MW 8.9 MW 10.7 MW 88 MW 180 MW

Drive beam power 140 MW

Acc. structure input 15 MW 6.5 MW 7.8 MW 67 MW 101 MW

Total beam(s) power 10 MW 5 MW 4 MW 21.6 MW 28 MW

Efficiency 13.5 % 10 % 9.4 % 6.7 %

Based on Linacs …

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Future Multi-MW machines

FCC-hh FCC-ee*)

Frequency

Technology klystrons klystrons

Total AC power

Cryogenic power (magnets) 0

Cryogenic power (RF)

Power source outputDesign for max reliabity! (cf. E.

Montesinos’ talk)

Acc. structure input

Total power to beam

Efficiency

… and Synchrotrons

*): preliminary estimates from http://cds.cern.ch/record/1588120

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CLIC in a nutshell

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FCC in a nutshell

Forming an international collaboration to study:

• pp-collider (FCC-hh) defining infrastructure requirements

• e+e- collider (FCC-ee) as potential intermediate step

• p-e (FCC-he) option

• 80-100 km infrastructure in Geneva area

~16 T 100 TeV pp in 100 km~20 T 100 TeV pp in 80 km

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Many small losses add up!

wall plug AC/DC power

converter RF power source useable RF

beam

loss

loss

loss

loss

Φ & loss

minimize losses!

recover waste RF power!

recover beam power!

The whole system must be optimized – not one efficiency alone

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Example: CLIC @ 3 TeV

28 MW

MB+DB production & transport, services, infrastructure

and detector

Dumps

Mainlinac

PETS

Drive beamacceleration

266 MW

173.0 MW

140 MW

109 MW

23.8 MW

Drive beampower extr.

Power suppliesklystrons

𝜼𝑹𝑭→𝒃𝒆𝒂𝒎=𝟎 .𝟐𝟕𝟕102 MW

(2 x 101 kJ x 50 Hz)

Main beam

594 MWModulator

337 MW

256 MW

‘wall plug’

Wall plug 100%

To DB-RF 57%

To DECEL 41%

To PETSout 73%

To Main Beam 28%

Overall η 4.7%

𝜂𝐾=0.65𝜂𝐾=0.75231 MW

293 MW 549 MW

(45 MW less!)

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This example () demonstrates that the R&D is worth the effort:Possible saving per year (assuming operation and $40/MWh): or $ 10 Million!

CLIC example continued

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… other areas of R&D affecting the overall efficiency:

This workshop concentrates on methods to increase the efficiency of RF power sources … so I skip this.

… but this is not the only area that affects the overall efficiency

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SC-RF R&D: larger !

1 .0 1 .2 1 .4 1 .6 1 .8 2 .0 2 .2 2 .41

2

5

1 0

2 0

5 0

1 00

T K bl

ue:PakW

R r es 1 0 n

red:P l

ossW

• Minimize residual resistance , maximize surface physics, technology, materials, fabrication techniques, shape optimisation, operating optimisation.

• Todays investment in R&D may pay off significantly!

Example: 800 MHz 5-cell cavity for 18 MV, is the cryogenic power at ambient temperature. Thanks: R. Calaga, S. Claudet, P. Lebrun!

x 4.4

Technology

x 1.6

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SC-RF R&D: Optimum ?• Superconducting RF – technology (example)

– Push coating techniques – on Cu substrate – performance reach?– Coating with Nb3Sn on Nb looks promising – note potential at 4.2 K !

Sam Posen et al. (Cornell): “RF Test Results of the first Nb3Sn Cavities coated at Cornell”, SRF 2013

The is only a factor 0.7 worse at 4.2 K compared to 2 K,the COP is about a factor 3 better! The impact on total power consumption is significant!

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Use the spent beam: ERL

10 GV

10 GV

Energy recovery: no beam loading

E.g.: the LHeC ERL (left) accelerates 6.4 mA of (continuous) electrons to 60 GeV. The “beam power” at collision is 384 MW – but the power consumption is <100 MW.

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Recover non-used RF power: Smart RF loads

1) http://accelconf.web.cern.ch/AccelConf/IPAC10/papers/wepd090.pdf2) http://accelconf.web.cern.ch/AccelConf/IPAC2012/papers/thppc023.pdf

Idea 1) – reconvert to DC power! Idea 2) – use high-T loads!

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Now have a interesting and constructive Workshop!

Thank you very much!