An Introduction to the LHeC

Large Hadron Electron Collider

M.Klein - BINP - 9/06/9 1

1. ep as a complement to pp and ee2. A summary of the project3. Remarks on the accelerator design studies

Visit of Karl Hubert Mess (CERN), Davide Tommassini (CERN) and Max Klein (U.Liverpool) toThe Budker Institute of Nuclear Physics of the Siberian Academy of Sciences (Novosibirsk)

Max KleinNovosibirsk 9/06/9

klein@ifh.de

HERA and ep/ee/pp

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Plenary ECFA, LHeC, Max Klein, CERN 30.11.2007

HERA 1992-2007

rising seahuge gluehard diffractionquark radius < 7 10-18 melectroweak unification

Глубоко-неупругое Рассеяние

Plenary ECFA, LHeC, Max Klein, CERN 30.11.2007

HERA - the first ep collider

quark+gluon densities in the protonphoton-quark/gluon physicsparton amplitudesmultijets, …

e and p fixed target experiments

No neutron structure exploredNo nuclear structure explored

In the accessed energy range:No SUSY No leptoquarksNo extra dimensions

1000 physicists for 25 yearsdeveloped the techniques of ep scattering at high energies, the accelerator, the collider experiments, the theory and analysis techniques. 800 PhD’s, 350 publications

ZEUS

H1

The Fermi Scale [1985-2010]

b quarktop quark

MW, H?

gluonh.o. strong

c,b distributionshigh parton densities

MZ , sin2 3 neutrinos

h.o. el.weak (t,H?)

ep e+e-

pp

The StandardModel Triumph

Tevatron

LEP/SLC

HERA CKM - B factories

The TeV Scale [2010-2035..]

W,Z,topHiggs??

New Particles??New Symmetries?

High Precision QCDHigh Density Matter

Substructure??eq-Spectroscopy??

ttbarHiggs??

Spectroscopy??

ep e+e-

pp

New Physics

LHC

ILC/CLICLHeC

A Summary of the LHeC Project

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The Large Hadron Electron Collider Project

1990: LEP*LHC (Aachen Workshop)2001: THERA (TESLA TDR)2005: LHeC: * DIS, Madison2006: 1033cm-2s-1: 2006 JINST 1 10001

2007 CERN Council and [r]ECFA2008 Divonne I, NuPECC, ICFA,ECFA2009 Divonne II (1.-3.9.), ECFA 11/09

2010: Conceptual Design Report http://www.lhec.org.uk

Accelerator Design [RR and LR]

Oliver Bruening (CERN),

John Dainton (CI/Liverpool)

Interaction Region and Fwd/Bwd

Bernhard Holzer (DESY),

Uwe Schneeekloth (DESY),

Pierre van Mechelen (Antwerpen)

Detector Design

Peter Kostka (DESY),

Rainer Wallny (UCLA),

Alessandro Polini (Bologna)

New Physics at Large Scales

Emmanuelle Perez (CERN),

Georg Weiglein (Durham)

Precision QCD and Electroweak

Olaf Behnke (DESY),

Paolo Gambino (Torino),

Thomas Gehrmann (Zuerich)

Claire Gwenlan (Oxford)

Physics at High Parton Densities

Nestor Armesto (CERN),

Brian Cole (Columbia),

Paul Newman (Birmingham),

Anna Stasto (MSU)

Oliver Bruening (CERN)John Dainton (Cockcroft)Albert DeRoeck (CERN)Stefano Forte (Milano)Max Klein - chair (Liverpool)Paul Newman (Birmingham)Emmanuelle Perez (CERN)Wesley Smith (Wisconsin)Bernd Surrow (MIT)Katsuo Tokushuku (KEK)Urs Wiedemann (CERN))

Guido Altarelli (Rome)Sergio Bertolucci (CERN)Stan Brodsky (SLAC)Allen Caldwell -chair (MPI Munich)Swapan Chattopadhyay (Cockcroft)John Dainton (Liverpool)John Ellis (CERN)Jos Engelen (CERN)Joel Feltesse (Saclay)Lev Lipatov (St.Petersburg)Roland Garoby (CERN)Roland Horisberger (PSI)Young-Kee Kim (Fermilab)Aharon Levy (Tel Aviv)Karlheinz Meier (Heidelberg, ECFA)Richard Milner (Bates)Joachim Mnich (DESY)Steven Myers, (CERN)Guenter Rosner (Glasgow, NuPECC)Alexander Skrinsky (Novosibirsk)Anthony Thomas (Jlab)Steven Vigdor (BNL)Frank Wilczek (MIT)Ferdinand Willeke (BNL)

Scientific Advisory Committee

Steering Committee

Working Group Convenors

Max Klein, University of Liverpool

Novosibirsk, BINP, 9.06.2009

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Ring – Ring Design tentative

€

2 ⋅1033cm−2s−1,5y :100 fb−1...50...80GeV

€

L =N pγ

4πeε pn⋅

Ieβ pxβ py

= 8.31032 ⋅Ie

50mA

m

β pxβ pncm−2s−1

€

Ie = 0.35mA ⋅P

MW⋅

100GeV

E e

⎛

⎝ ⎜

⎞

⎠ ⎟

4

Subject to LHC, power, tuneshifts etc. – 100 times HERA luminosity

SPL

9M.Klein - BINP - 9/06/9

LHeC

€

L =N pγ

4πeε pnβ*⋅P

Ee= 5 ⋅1032 ⋅

P /MW

Ee /GeVcm−2s−1 LINAC-Ring Design - tentative

€

3⋅1032cm−2s−1,5y;30 fb−1@50GeV ....10 fb−1@150GeV

F. Zimmermann ECFA11/08

Based on sLHC. e+ ? , w/o energy recovery

10M.Klein - BINP - 9/06/9

1. Unfolding Proton Structure – DIS, complete for the first time

+parton dynamicsphoton structureneutron structure..InstantonsOdderonsMultiquark exoticaIntrinsic heavy flavour

Single t, tbar factory O(10)pb

2uv+dv

ssbar

cb

11M.Klein - BINP - 9/06/9

2. Exploration of High (“swerch”) Scales – High Precision in ep

GUT/SUSY unification?effective couplings?resolving CI type observations at the LHC

… access to much higher scales with precision DISchallenge to NkLO QCD

LHeC freezes the pdfs to allow newphysics to be revealed. HERA+BCDMSreshuffle the sea… ED similar study 12M.Klein - BINP - 9/06/9

3. Complementing the LHC – Higgs and gluon (for example)

clean(er) environment

huge range in Q2

access to large x,high mass region

B tagging mandatory.

SM Higgs MSSM HiggsWWHbbar

Bgd study ongoing, B tagging promising

13M.Klein - BINP - 9/06/9

4. New Physics in the eq Sector – unique eq as compared to qq

?LQ, RPV SUSYSpectroscopy

?Excited fermions

14M.Klein - BINP - 9/06/9

5. Parton Saturation – low x beyond the unitarity limit in DIS ep

DiffractiveB,W,Z,H?

Forward jets, VMs..Saturation from precision F2 and FL 15M.Klein - BINP - 9/06/9

6. Partonic Structure of Nuclei – new phase of matter

Gluon “a desaster” (NA)

Nuclear parton distributionsxg ~ A1/3

black disc limit (F2~ln(1/x))50% diffraction..A must to understand AA

16M.Klein - BINP - 9/06/9

Surprises and Theory

S.Adler, arXiv:hep-th/9610104

Things may evolve differentlythan we think, but one canrely on the ingenuity of ourtheory colleagues to deal withthe unexpected.

Design a maximum energy, highluminosity, affordable collider

Tbilissi 76

17M.Klein - BINP - 9/06/9

CDR

18M.Klein - BINP - 9/06/9

Organisation Accelerator Design Concepts

IR for simultaneous pp and ep operation

Bypass around ATLAS+CMS

Contact persons for workpackages [BE-ABP, RF, BT, VAC, PO]O.Bruening, B.Holzer, E.Chiapola, H.Burkhardt,B.Goddard, W.Herr, F.ZimmermannM.Jimmenez, KH.Mess, D.Tommasini, F.Bordry,G.Hofstatter, L.Rinolfi, D.Schulte.

Collaboration: Novosibirsk, EPFL Lausanne, SLAC , CI, DESY, BNL, Cornell 19M.Klein - BINP - 9/06/9

L1

M.Klein - BINP - 9/06/9 20

Tentative design: full coverage, high precision, no material…- modular for installation (CMS), dimensions determined by beam pipe-IR-synchr. rad. : to be simulated - focusing magnets nearer to IR for high Q2, high luminosity (instrumented?) - variation of beam energies to access low Q2 and large x at “medium” Q2 ~ 20000 GeV2

- contacts to ILC (4th concept: coil? ALIROOT) and ATLAS/CMS detector developments

P.Kostka, A.Polini, R.Wallny

Deep Inelastic Scattering

SLAC 69: 2m LINAC: a “bold extrapolationof existing technology” to “collectdata which may be of future use…”

50 000 times Q2 possibly with5 times the accelerator length..

In one year we hope to know how to build the ep/eA collider complement of the LHC, and we will start to lookinto the TeV scale physics with pp.The CDR should help shaping our future.

www.lhec.org.uk, EPAC08, .. also forproper referencing of work presented above.

Involves manygifted and enthusiasticcolleagues in thy, exp and acc,Supported by ECFA, CERN, NuPECC.

21M.Klein - BINP - 9/06/9

Accelerator Design Studies

M.Klein - BINP - 9/06/9 22

Max Klein LHeC 2/09

Machine Requirements

-New physics expected at (multi??) TeV scale. Low x=Q2 /sx, s=4EeEp

highest possible Ee and Ep 1 TeV with 50GeV on 5000 GeV

-New physics is rare [ep (Higgs) = O(100)fb] , rate at high Q2 , large x

L has to exceed 1032 and preferentially reaches 1033 and beyond

-New states, DVCS, electroweak physics

Need electrons and positrons and high lepton beam polarisation

-Neutron structure terra incognita

Deuterons

-Partonic Structure of Nuclei

a series of nuclei, Ca, Pb

Max Klein LHeC 2/09

Machine Considerations and Studieshigh Ee,p,A, e polarised, high Luminosity

generalities

simultaneous ep and pp

power limit set to 100MW

IR at 2 or 8

p/A:

SLHC - high intensity p(LPA/50ns or ESP/25ns)

Ions: via PS2new source for deuterons

e Ring:

bypasses: 1 and 5[use also for rf]

injector: SPL, or dedicated

e LINAC:

limited to ~6km (Rhone)for IP2, longer for IP8CLIC/ILC tunnel.?

RR

LR

CERN power consumption

M.Klein - BINP - 9/06/9 25

Myers limit of 100 MW *2000 h/a 200 GWh, less P is desirable

A lattice

M.Klein - BINP - 9/06/9 26

F.Willeke, CERN Seminar, June 14th, 2006

A lattice

M.Klein - BINP - 9/06/9 27

F.Willeke, CERN Seminar, June 14th, 2006

A lattice

M.Klein - BINP - 9/06/9 28

F.Willeke, CERN Seminar, June 14th, 2006 -- cf also J.Jowett and B.Holzer/A.Kling Divonne 9/2008

Max Klein LHeC 2/09

e Ring Further Considerations

Mount e on top of p - feasible at first sight needs further, detailed study of pathway

Installation: 1-2 years during LHC shutdowns. LEP installation was ~1 year into empty tunnel. Radiation load of LHC pp will be studied.

Injection: LEP2 was 4 1011 e in 4 bunches LHeC is 1.4 1010 in 2800 bunches may inject at less than 20 GeV.

Power for 70 (50) GeV Ee fits into bypasses:

SC system at 1.9o K (1 GHz) r.f. coupler to cavity: 500 kW CW - R+D 9 MV/cavity. 100(28) cavities for 900(250)MV cavity: beam line of 150 (42) m klystrons 100 (28) at 500kW plus 90 m racks .. gallery of 540 (150) m length required.

T.Linnecar

Bypasspoint 5

2 tunnels for ring and shielded rf

Bypass through survey gallery13m distance, 2 shafts

Bypass independent of IR~30m distance, 1 shaft

Tunnel connection (CNGS, DESY)

Lattice studyH.Burkhardt

S.Myers, J.Osborne

Max Klein LHeC 2/09

Interaction Region Design

builds on F.Willeke et al, 2006 JINST 1 P10001 design for 70 GeV on 7000 GeV, 1033

and simultaneous ep and pp operation

B.Holzer, A.Kling, et al Divonne 08

Luminosity: Ring-Ring

€

L =N pγ

4πeε pn⋅

Ieβ pxβ py

= 8.31032 ⋅Ie

50mA

m

β pxβ pncm−2s−1

€

εpn = 3.8μm

N p =1.7 ⋅1011

σ p(x,y ) =σ e(x,y )

β px =1.8m

β py = 0.5m

€

Ie = 0.35mA ⋅P

MW⋅

100GeV

Ee

⎛

⎝ ⎜

⎞

⎠ ⎟

4

1033 can be reached in RREe = 40-80 GeV & P = 5-60 MW.

HERA was 1-5 1031 cm-2 s-1

Gain O(100) with LHC p beam

Integrated luminosities of O(50)fb-1

likely klystroninstallation limitSynchrotron rad!1033

Max Klein LHeC 2/09

Ring-Ring Parameters

€

L =N pγ

4πeε pn⋅

Ieβ pxβ py

L = 8.31032 ⋅Ie

50mA

m

β pxβ pncm−2s−1

€

Ie = 0.35mA ⋅P

MW⋅

100GeV

Ee

⎛

⎝ ⎜

⎞

⎠ ⎟

4

Luminosity safely 1033cm-2s-1

HERA was 1-5 1031

Table values are for 14MW synradloss (beam power) and 50 GeVon 7000 GeV. May have 50 MWand energies up to about 70 GeV.

LHC upgrade: Np increased.Need to keep e tune shift low:by increasing p, decreasing e but enlarging e emittance,to keep e and p matched.

LHeC profits from LHC upgradebut not proportional to Np

B.Holzer

e injector from SPL to Point 2 via TI2 Alternative injectors considered too (cf H. Burkhard, DIS08, Proceedings)

SPL

PS2

LINAC4

Max Klein LHeC SAC-CI 11/08

SPL as e injector/linac to Point 2 via TI2 tunnel here with new re-circulating loop (r ~20m, l~ 400 m), use of service tunnel or dogbone to be studied … 20 GeV

Drawing by TS CERN

for SPL see CERN-AB-2008-061 PAF. R.Garoby et al.

proton parameters: LPA upgrade sLHC: Nb=5x1011, 50 ns spacing, ε=3.75 m, *=0.1 m, z=11.8 cm

e- energy [GeV] 30 100 100

comment SPL* (20)+TI2 LINAC LINAC

#passes 4+1 2 2

wall plug power RF+Cryo [MW] 100 (1 cr.) 100 (3 cr.) 100 (35 cr.)

bunch population [109] 10 3.0 0.1

duty factor [%] 5 5 100

average e- current [mA] 1.6 0.5 0.3

emittance ε [m] 50 50 50

RF gradient [MV/m] 25 25 13.9

total linac length =1 [m] 350+333 3300 6000

minimum return arc radius [m] 240 (final bends) 1100 1100

beam power at IP [MW] 24 48 30

e- IP beta function [m] 0.06 0.2 0.2

ep hourglass reduction factor 0.62 0.86 0.86

disruption parameter D 56 17 17

luminosity [1032 cm-2 s-1] 2.5 2.2 1.3

F.Zimmermann, S. Chattopadhyay

Pulsed CW

Max Klein LHeC 2/09

Luminosity: Linac-Ring

€

L =N pγ

4πeε pnβ*⋅P

Ee= 5 ⋅1032 ⋅

P /MW

Ee /GeVcm−2s−1

LINAC is not physics limited in energy, but by its cost/length + power

1032 are in reach at large Ee.

LINAC - no periodic loss+refill,~twice as efficient as ring…

Note: positron source challenge:

LHeC 1032 needs few times 1014 /sec

€

s = 2TeV

€

εpn = 3.8μm

N p = 5 ⋅1011

β * = 0.10m

SLHC - LPA

cf. R.Garoby EPS07, J.Koutchouk et al PAC07M.Tigner, B.Wiik, F.Willeke, Acc.Conf, SanFr.(1991) 2910

A LINAC Design-Site

100 GeV e LINAC with recirculator.

ILC/CLIC tunnel much deeper

CLIC cavities don’t fit to LHC

CW LINAC longer: energy recovery

ERL: may get some gain.[Tigner 1965, Jlab, Cornell, …]

Drawing by TS CERN

Tasks on the Machine for the CDR - incomplete

-Infrastructure (Interaction Region, SPL/TI2, LINAC site)

-IR for ring and for LINAC and its interface with LHC, e beam and the detector

-Optics and lattice designs (high luminosity and small angle acceptance)

-Identification of R+D projects for LHeC (active magnets?, rf Coupler, …)

-LINAC: is ER feasible for a 100 GeV beam or is the LR limited to 1032 ? what is the luminosity in e+ ?

-Ring: magnet design for ring on top of the LHC installation: pathway and radiation injector (SPL and its possible use for an initial eA phase)

Max Klein LHeC SAC-CI 11/08

L1 Detector: version for low x PhysicsMuon chambers (fwd,bwd,central)

Coil (r=3m l=8.5m, 2T) [Return Fe not drawn,

2 coils w/o return Fe studied]

Central Detector

Hadronic Calo (Fe/LAr)El.magn. Calo (Pb,Sc)GOSSIP (fwd+central)[Gas on Slimmed Si Pixels][0.6m radius for 0.05% * pt in 2T field]

PixelsElliptic beam pipe (~3cm)

Fwd Spectrometer (down to 1o)

TrackerCalice (W/Si)FwdHadrCalo

Bwd Spectrometer (down to 179o)

TrackerSpacal (elm, hadr) To be extended further in fwd direction. Tag p,n,d. Also e, (bwd)

Low x Detector – rz view

Max Klein LHeC 2/09

High Q2 Detector – rz view

Max Klein LHeC 2/09

L1 Detector: version for hiQ2 PhysicsMuon chambers (fwd,bwd,central)

Coil (r=3m l=8.5m, 2T)

Central Detector

Hadronic Calo (Fe/LAr)El.magn. Calo (Pb,Sc)GOSSIP (fwd+central)PixelsElliptic pipe (~3cm)

Fwd Calorimeter (down to 10o)

Lepton low magnetsFwdHadrCalo

Bwd Spectrometer (down to 170o)

Lepton low magnetsSpacal (elm, hadr)

Active magnets? T.Greenshaw et al.

Summary

M.Klein - BINP - 9/06/9 44

LHeC Conceptual Design being prepared as CERN-ECFA-NuPECC Activity [2007-10] CDR to include: Acc, IR, Infrastructure, Detector, Physics Programme

Aim: TeV cms energy eq collider design with maximum luminosity as an upgrade to the LHC and a complement to pp and ee (or μμ?) TeV scale colliders, with a built in eA phase and the aim to simultaneously run pp and ep by 2020+

Two options for CDR: RING-RING: 50-80 GeV, 1033, ring to be installed on top of LHC, bypasses

LINAC-RING: 50-150 GeV, 1032 (w/o energy recovery), a new design, ILC cavities

Time schedule: CDR: Divonne 1-3.9.2009, ECFA November 2009, DIS 4/2010 Florence CDR in 2010

Cпacибо

References for Ring Design

M.Klein - BINP - 9/06/9 45

LEP

J. Dainton et al (F.Willeke) 2006 JINST 1 10001F. Willeke, Accelerator Seminar at CERN, 14/06/2006 H.Burkhardt, Talk and Proceedings at DIS08, London, April 2008 [injector, bypass] Talks at Divonne 9/2008 (T.Linnecar rf, B.Holzer/A.Kling e optics, J.Jowett lattice, ..)EPAC08 J.Dainton, H.Burkhardt, F.Zimmermann, 3 papers submitted, Genua, May 2008PAC09 F.Zimmermann et al., Talk and Paper submitted, Vancouver, May 2009

Mostly availabe on the LHeC websitehttp://www.lhec.org.uk