the lhec and future ep collisions at cern
DESCRIPTION
J. Osborne. The LHeC and Future ep Collisions at CERN. Frank Zimmermann LHeC Workshop , Chavannes-de- Bogis 20 January 2014. Work supported by the European Commission under Capacities 7th Framework Programme, Grant Agreement 312453. Many contributors to accelerator study: - PowerPoint PPT PresentationTRANSCRIPT
The LHeC and Future ep Collisions at CERN
Frank ZimmermannLHeC Workshop , Chavannes-de-Bogis
20 January 2014
Work supported by the European Commission under Capacities 7th Framework Programme, Grant Agreement 312453
J. Osborne
Many contributors to accelerator study: Jose Abelleira, Chris Adolphsen, Husnu Aksakal, Rob Appleby, Mei Bai, Desmond Barber, Nathan Bernard, Sergio Bertolucci, Alex Bogacz, Frederick Bordry, Luca Bottura, Chiara Bracco, Hans Braun, Stephen Brooks, Oliver Brüning, Eugene Bulyak, Helmut Burkhardt, Rama Calaga, Swapan Chattopadhyay, Ed Ciapala, Kenan Ciftci, Reina Ciftci, John Dainton, Anders Eide, Emre Eroglu, Miriam Fitterer, Hector Garcia, Brennan Goddard, Yue Hao, Friedrich Haug, Bernhard Holzer, Erk Jensen, Miguel Jimenez, John Jowett, Dmitry Kayran, Max Klein, Peter Kostka, Vladimir Litvinenko, Karl Hubert Mess, Attilio Milanese, Steve Myers, Zafer Nergiz, Ed Nissen, John Osborne, Dario Pellegrini, Tatiana Pieloni, Abrahan Pinedo, Alessandro Polini, Vadim Ptitsin, Louis Rinolfi, Lucio Rossi, Giovanni Rumolo, Stephan Russenschuck, Jake Skrabacz, Daniel Schulte, Ilkyoung Shin, Peter Sievers, Mike Sullivan, Saleh Sutansoy, Hugues Thiesen, Luke Thompson, Rogelio Tomas, Davide Tommasini, Dejan Trbojevic, Joachim Tückmantel, Alessandra Valloni, Alessandro Variola, Ferdinand Willeke, Vitaly Yakimenko, Fabian Zomer, … ++
LHeC CDR published in 2012 (~600 pages)
RR LHeC:new ring in LHC tunnel,with bypassesaround experiments
LR LHeC:recirculatinglinac withenergy recovery
Large Hadron electron Collider
baselineconfiguration
CDR performance targets
e- energy ≥60 GeV (2x HERA)luminosity ~1033 cm-2s-1 (25x HERA)total electrical power for e-: ≤100 MWoperation simultaneous with LHC pp physics
e+p collisions (with similar luminosity?)e-/e+ polarizationdetector acceptance down to 1o
two 10-GeV SC linacs, 3-pass up, 3-pass down; 6.4 mA, 60 GeV e-’s collide w. LHC protons/ions
(C=1/3 LHC allows for ion clearing gaps)
A. Bogacz, O. Brüning, M. Klein, D. Schulte, F. Zimmermann, et al
LHeC Linac-Ring ERL layout
ion gaps & circumferencegap turn 1gap turn 2gap turn 3
gap turn 1gap turn 2gap turn 3
CLHeC=CLHC/n
future: CLHeC+=CFHC/m
IP#1
IP#2
DC=k CLHeC
LHC
FHC
m, n (=3), k: integer
Alice
J.Osborne / A.Kosmicki CERN/GS
Prevessin site
LHC
TI2
LHeC baseline: underground layout / integration with LHC;example: Point 2
ERL Linac Optics
flexible momentum compaction cell; tuned for small beam size (low energy) or low De (high energy)
A. Bogacz
ERL Arc Optics
to be studied: alternative based on FFAG-type arcs à la eRHIC
Non-colliding proton beam
colliding proton beam
Electron beam
Synchrotron radiation
High-gradient SC IR quadrupoles based on Nb3Sn for colliding proton beam with common low-field exit hole for electron beam and non-colliding proton beam
detector integrated dipole: 0.3 T over +/- 9 m
S. Russenschuck
Inner triplets
Exit hole for electrons & non-colliding protons
Inner triplets
Q1Q2
Q2
Q1
Nb3Sn (HFM46): 5700 A, 175 T/m, 4.7 T at 82% on LL (4 layers), 4.2 K
Nb3Sn (HFM46): 8600 A, 311 T/m, at 83% LL, 4.2 K
46 mm (half) ap., 63 mm beam sep.
23 mm ap.. 87 mm beam sep.
0.5 T, 25 T/m 0.09 T, 9 T/m
LHeC IR layout & SC IR quadrupolesR. Tomas
new design with larger l*
ring-ringee>>ep, be
*<< bp*
ring-linacee≈ep, be
*≈ bp*
minimum e- beta functionand beam sizeslimited by hourglass effect;small crossing angle acceptable;little disruption
much smaller e- emittancesmaller beta functionand beam sizes possible;head-on collision required;significant disruption
; hourglass reduction factor
colliding unequal beams
Dhgepp
pb HHIN
eL
*
, 1
4
1
luminosity of LR collider:
highest protonbeam brightness available(may dependon bunch spacing)
Nb=1.7x1011
eN=3.75 mm
decreasedproton b* function: - reduced l* (23 m → 10 m)- squeeze only one p beam- new magnet technology Nb3Sn
b*p=0.1 m
maximize geometricoverlap factor- head-on collision- small e- emittance
qc=0Hhg≥0.9
(round beams)
average e-
current limited by energy recovery
efficiency
Ie=6.4 mA
HD~1.3D. SchulteLHeC2010
path to 1033 cm-2s-1
LHeC baseline parameters parameter [unit]species e- pbeam energy (/nucleon) [GeV] 60 7000bunch spacing [ns] 25 (50) 25 (50)bunch intensity (nucleon) [1010] 0.1 (0.2) 17beam current [mA] 6.4 860rms bunch length [mm] 0.6 75.5polarization [%] 90 nonenormalized rms emittance [mm] 50 3.75geometric rms emittance [nm] 0.43 0.50IP beta function bx,y* [m] 0.12 0.10
IP rms spot size [mm] 7.2 7.2synchroton tune Qs - 1.9x10-3
LHeC baseline parameters – cont’dparameter [unit]species e- phadron beam-beam parameter x 0.0001 (0.0002)lepton disruption parameter D 6crossing angle 0hourglass reduction factor Hhg 0.91
pinch enhancement factor HD 1.35
c.m. energy ( /nucleon) [GeV] 1300luminosity / nucleon [1033 cm-1s-1] 1.3
BBU: beam stability requires damping (Q~105) detuning helps further (Df/frms~0, or 0.1%) , 802 MHz
D. Pellegrini,D. Schulte
ERL Beam Dynamics
SLC CLIC(3 TeV)
ILC(RDR)
LHeC
Energy 1.19 GeV 2.86 GeV 5 GeV 60 GeV
e+/ bunch at IP 40 x 109 3.72x109 20 x 109 2x109
e+/ bunch before DR inj. 50 x 109 7.6x109 30 x 109 N/A
Bunches / macropulse 1 312 2625 N/A
Macropulse repet. rate 120 50 5 CW
Bunches / second 120 15600 13125 20x106
e+ / second 0.06 x 1014 1.1 x 1014 3.9 x 1014 400 x 1014
X 18X 65
X 6666L. Rinolfi
e+ source requirements
possible e+ source options • recycle e+ together with energy, multiple use,
damping ring in SPS tunnel w t~2 ms • Compton ring, Compton ERL, coherent pair
production, or undulator for high-energy beam• 3-ring transformer & cooling scheme
accumulator ring (N turns)
fast cooling ring (N turns)
extraction ring (N turns)
(Y. Papaphilippou)
(E. Bulyak)
(H. Braun, E. Bulyak,T. Omori,V. Yakimenko)
(D. Schulte)
LHeC baseline parameters incl. e-Pb parameter [unit]species e- p Pb (ult.)beam energy (/nucleon) [GeV] 60 7000 2760bunch spacing [ns] 25 (50) 25 (50) 100bunch intensity (nucleon) [1010] 0.1 (0.2) (0.4) 17 2.5beam current [mA] 6.4 860 10.5rms bunch length [mm] 0.6 75.5 75.5polarization [%] 90 none Nonenormalized rms emittance [mm] 50 3.75 ~1.4geometric rms emittance [nm] 0.43 0.50 0.5IP beta function bx,y* [m] 0.12 0.10 0.10
IP rms spot size [mm] 7.2 7.2 7.2synchroton tune Qs - 1.9x10-3 1.9x10-3
LHeC baseline parameters incl. e-Pb – cont’dparameter [unit]species e- p Pb (ult.)hadron beam-beam parameter x 0.0001 (0.0002) 0.0001lepton disruption parameter D 6 0.3crossing angle 0 0hourglass reduction factor Hhg 0.91 0.91
pinch enhancement factor HD 1.35 1.0
c.m. energy ( /nucleon) [GeV] 1300 814luminosity / nucleon [1033 cm-1s-1] 1.3 0.1
system wall plug powercryogenics (Q0=2.5x1010) 21 MW (P∞1/Q0)RF operation & microphonics control
24 MW
addt’l RF power to compensate SR losses (12 MW at 6.4 mA at rdip=764 m ([R=1 km with F=76.4%])
24 MW (P∞Ie/rdip2)
injector 7 MWmagnets (arcs + IR) 4 MWtotal ~80 MW
electrical power budget
J. Skrabacz,2008
racetrack shape with acceleration in one or both straight sections; shape optimized for minimum construction (& operation) cost
Single or double acceleration? How many revolutions for optimum energy gain?Can we reduce emittancegrowth and cost?
choice of baseline layout
input cost figures (2008 study)rough estimate for cost / (unit length) extracted from XFEL, ILC and ELFE designs:linac: 160 k$/m
- with an effective gradient of 11.8 MV/m (XFEL)arc section: 50k$/m
- 300 M$ per ILC Damping Ringdrift straight: 10k$/m
- vacuum + perhaps some diagnostics?, taken as ~20% of cost of arc section from ELFE design
ILC tunnel cost: ~5k$/m- already taken to be included in above numbers- otherwise important only for the straight drifts,
potentially raising the drift cost to 15k$/m
construction cost at 60 GeV
single linac
double linac
2-3 circulations are optimum at 60 GeV(w/o restraining energy loss)
~400 MEuro
J. Skrabacz(assuming 15 MV/m)
each pointhas cost-optimizedlengths of linac,arc, and drifts
3 turns2.5 turns
effective cost = construction cost + SR-dependent operation cost= construction cost+ l DESR
effective cost
[ ] l = M$/GeV
value for weight factor l?
Ie=6.4 mA with DE=1 GeV over 1 year (107 s) → 36 GWh SRF electrical power; over 10 yrs: 360 GWhelectricity cost ~50 $/MWh → ~20 M$ in total
l=10-100 M$/GeV!
optimized cost vs energyJ. Skrabacz
“optimum of optimum”cost increasesabout linearly withenergy
adding weight parameter l in units of M$/(GeV energy loss)to limit operating cost
J. Skrabacz, “Optimizing Cost and Minimizing Energy Loss in the Recirculating Race-Track Design of the LHeC Electron Linac,”U.M., CERN REU, 2008
opt. circumference vs energyJ. Skrabacz
total circumferencealso increaseslinearly withenergy
better shapes?J. Skrabacz
“ballfield” designs with additional shape parametersmight reduce energy loss, emittance growth, or cost
extreme ballfields vs racetrack
racetrack looks best after all
J. Skrabacz60 GeV
cost-optimized #turns vs energyJ. Skrabacz
above 60 GeVsingle recirculation may be optimum!above ~140 GeVsingle linac!
l=100
beam energy
l=10 M$/GeV
l=100 M$/GeV
20 GeV 4.5 3.540 GeV 3.5 2.560 GeV 3.5 1.580 GeV 3.5 1.5100 GeV 2.5 1.5120 GeV 2.5 1.5140 GeV 1.5 0.5
pulsed w/o energy recovery
140-GeV linacinjector dump
IP7.9 km
Ee=140 GeV, <Ie>=0.27 mA, L≈4x1031 cm-2s-1 , extendable in energy
0.4 km
final focus
V. Litvinenko, 2nd LHeC workshopDivonne 2009cw with 2-beam energy recovery
L≈1035 cm-2s-1 , no SR, efficient ER, CLIC expertise, 2 linacs
single-pass higher energy linacs
• L ≥ 1034 cm-2s-1 needed for ep Higgs physics• higher brightness p beams for HL-LHC (LIU)• further squeezing bp* looks possible• higher e- current & smaller e- emittance
- 6.4 mA → 12.8 or 25.6 mA(Cornell ERL: 100 mA; BNL eRHIC ERL: 50 mA (pol.))
- ge = 50 mm → 20 mm at 1 nC bunch charge(LCLS, PITZ sources ≤ 1 mm)
- we still had 20 MW power margin till 100 MW- trend towards SC cavities with higher Q0
(→ lower cryo power)
higher luminosity
normalized emittance for 1 nC has been reduced from tens of mm to 1 mm
0.0
5.0
10.0
15.0
20.0
25.0
30.0
1979 1984 1989 1994 1999 2004
Year
No
rma
lize
d R
MS
Em
itta
nc
e a
t 1
nC
(m
m-m
rad
) Thermionic Injectors
PhotoinjectorsSLAC
Boeing
BNL
LANL - APEX
LANL – AFELBNL/UCLA/SLAC
BNL/KEK/SHIBNL/UCLA/SLAC
PITZ scaling: (nC)m)( 7.0 qn
LCLS scaling: (nC)m)( 1 qn
LHeCbaseline50 mm
Bruce Carlsten, SPACE CHARGE 2013
higher-Q0 Nb SRF cavities
Q0=1011
Q0=3x1010
18 MV/m 4 MV/m
world-record Q0 for a multi-cell cavity of the Cornell ERL, June 2013
Horizontal Test Cryostat
LHeC baseline considers Q0=2.5x10 10 at lower fRF
M. Liepe & S. Posen
34Future Circular Collider StudyMichael BenediktP5 Meeting 16 December 2013
potential of Nb3Sn SRF cavities
Data from P. Dhakal
R&D progressingat JLAB& Cornell
Robert Rimmer, JLAB
LHeC target
LHeC Higgs factory (LHeC-HF) parameters parameter [unit]species e- pbeam energy (/nucleon) [GeV] 60 7000bunch spacing [ns] 25 25 bunch intensity (nucleon) [1010] 0.1 → 0.4 17→ 22beam current [mA] 6.4 → 25.6 860 → 1110normalized rms emittance [mm] 50 → 20 3.75 → 2.5geometric rms emittance [nm] 0.43 → 0.17 0.50 → 0.34IP beta function bx,y* [m] 0.12 → 0.10 0.10 → 0.05
IP rms spot size [mm] 7.2 → 4.1 7.2 → 4.1lepton D & hadron x 6 → 23 0.0001→ 0.0004hourglass reduction factor Hhg 0.91→ 0.70
pinch enhancement factor HD 1.35
luminosity / nucleon [1033 cm-1s-1] 1.3 → 16
SAPPHiRE: Small Accelerator for Photon-Photon Higgs production using Recirculating Electrons
Reconfigured LHeC
SAPPHiRE gg Higgs factory100 MW total wall-plug power, Lgg ~6x1032 cm-2s-1
(1 year = 107 s at design luminosity)
machine LHeC LHeC-HF SAPPHiRE
luminosity [1034 cm-2s-1]
0.1 (ep) 2 (ep) 0.06 ( gg>125 GeV)
Higgs production cross section
~200 fb ~200 fb >1.7 pb
no. Higgs/yr 2k 40k >10k
LHeC ep & gg Higgs factories
SRF/ERL test facility at CERN
Alessandra Valloni
important milestone and key to future projects
up to 4 cryo-modulesbeam energy up to 1 GeV
beyond 2030?
“For time and the world do not stand still…”
John F. Kennedy
RECFA - Budapest– 5th October 2013
15 T 100 TeV in 100 km20 T 100 TeV in 80 km
FCC (Future Circular Colliders)
CDR and cost reviewfor the next ESU (2018)(including injectors)
FCC - 80-100 km tunnel infrastructure in Geneva area – design driven by pp-collider (FHC) requirements
with possibility of e+e- (TLEP) and p-e (FHeC)
F. Bordry
e- energy = 60, 120, 250 GeV p energy = 50 TeVIP spot size determined by pe- current from FLC (SR power ≤ 50 MW)#IPs = 1 or 2
key parameters for FHLC/FHeC
collider parameters e± scenarios protonsspecies e± e± e± pbeam energy [GeV] 60 120 250 50000bunch spacing [ms] 0.125 2 33 0.125 to 33bunch intensity [1011] 3.8 3.7 3.3 3.0beam current [mA] 477 29.8 1.6 384 (max)rms bunch length [cm] 0.25 0.21 0.18 2rms emittance [nm] 6.0, 3.0 7.5, 3.75 4, 2 0.06, 0.03bx,y*[mm] 5.0, 2.5 4.0, 2.0 9.3, 4.5 500, 250sx,y* [mm] 5.5, 2.7beam-b. parameter x 0.13 0.050 0.056 0.017hourglass reduction 0.42 0.36 0.68CM energy [TeV] 3.5 4.9 7.1luminosity[1034cm-2s-1] 21 1.2 0.07
preliminary (!) parameters for FHeC
http://indico.cern.ch/e/fcc-kickoff
FCC Kick-off Meeting inGeneva next month
Infrastructure, cost estimates
P. Lebrun
VL Hadron collider
D. Schulte
Hadron injectors
B. Goddard
e- p option Integration aspects O. Brüning
Future Circular Colliders - Conceptual Design StudyStudy coordination, host state relations, global cost estimate
M. Benedikt, F. Zimmermann
e+ e- collider
J. Wenninger
High Field Magnets
L. BotturaSupercon-ducting RFE. Jensen
CryogenicsL. TavianSpecific
Technologies(MP, Coll, Vac,
BI, BT, PO)JM. Jimenez
Physics and experiments
Hadron physic Experiments, infrastructureA. Ball, F. Gianotti,
M. Mangano
e+ e- exper., physics
A. Blondel J.Ellis, P.Janot
e- p physics +M. Klein
Operation aspects, energy efficiency, OP & mainten., safety, environment.
P. Collier
Planning (Implementation roadmap, financial planning, reporting)F. Sonnemann
Team preparing FCC Kick-Off & Study
contributors to LHeC design effort
study coordinator deputy coordinator
looking for int’l co-conveners!
PSB PS (0.6 km)SPS (6.9 km)
HL-LHC
TLEP? (80-100 km, e+e-, up to ~350 GeV c.m.)
VHE-LHC/FHC (pp, up to 100 TeV c.m.)
possible long-term strategy
LHeC/FHeC: e± (60-250 GeV) – p (7 and/or 50 TeV) collisions !
≥50 years e+e-, pp, e±p/A physics at highest energies
LHeC & SAPPHiRE?
LHC (26.7 km)
LHeC as TLEP injector?
LHeC-FHC collider if TLEP is not constructed?!
FHeC as TLEP-FHCCollider ?!
LHC Constr. PhysicsProto.Design, R&D
HL-LHC Constr. PhysicsDesign, R&D
VHE-LHC/FHC
Constr.Design, R&D
TLEP? Constr. PhysicsDesign, R&D
Physics
LHeC/SAPPHiRE Constr. PhysicsDesign, R&D
possible long-term time line
FHeC Constr.Design, R&D Physics
PhysicsConstr.+ LHeC-FHC
(with TLEP)
(w/o TLEP)
LHeC design matured over past 6 years; CDR published in 2012; ERL baseline looks conservative
design parameters (circumference, beam energy, RF frequency, number of passes, etc.) can be further optimized for cost and/or performance
new high luminosity parameters for Higgs physicsLHeC-based gg collider Higgs factory (SAPPHiRE) LHeC compatible with long-term strategy (FCC)
• LHeC/SAPPHiRE RF & cryo identical to TLEP/FLC’s – can be reused; remaining LHeC can serve as TLEP injector
•FHeC: combination of TLEP/FLC and VHE-LHC/FHC with highest-energy highest-luminosity e±p collisions; direct LHeC-FHC collisions as backup
summary
thank you for your attention