how do we get to 100 tev ?

How Do We Get to 100 TeV?

Vladimir ShiltsevAccelerator Physics Center \ FermilabApril 9, 2014

Abstract Particle colliders for high-energy physics have been in the

forefront of scientific discoveries for more than half a century. The accelerator technology of the colliders has progressed immensely, while the beam energy, luminosity, facility size, and cost have grown by several orders of magnitude. The method of colliding beams has not fully exhausted its potential but has slowed down considerably in its progress.

I will briefly review the development of the collider technology, examine near-term collider projects that are currently under development, derive a simple scaling model for the cost of large accelerators and colliding beam facilities based on costs of 17 big facilities which have been either built or carefully estimated.  The cost parameterization will guide our consideration of possible future frontier accelerator facilities. I will conclude with an attempt to look beyond the current horizon and to find what paradigm changes are necessary for breakthroughs in the field.

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V.Shiltsev | IOP2014: 100 TeV Collider

29 Colliders Built… 7 Work “Now”

VEPP-2000VEPP-4M

LHC

DAFNE

BEPC-II

KEK-B

RHIC

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Colliders: Glorious Past

V.Shiltsev | IOP2014: 100 TeV Collider

E~exp(t/5yrs)

UNK

?

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Colliders for Tomorrow (ca 2030)

V.Shiltsev | IOP2014: 100 TeV Collider

• LHC:– high-luminosity LHC (x5 design L)– LHeC

• Lepton Colliders– ILC– CLIC– +- Collider

• Higgs Factory:– linac based e+e-– ring based e+e- or +-

Depend on:

1. LHC results2. Cost-Performance-

Feasibility

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- see also F.Zimmerman talk

Let’s Talk About MONEY

… scientifically, no emotionsV.Shiltsev | IOP2014: 100 TeV Collider6

Scale of Numbers• US HEP budget is ~0.8 B$ / year

– Can(?) shoot for (25% x 0.8B$ x 10 yrs) = 2 B$

– with int’l partners x 2 (?) = 4 B$• World’s Particle Physics ~3 B$ / year

– can possibly afford “global” 8-12 B$ project

– will require all of us as >1000 experts needed

– “one machine for all” = no domestic for 2 out of 3V.Shiltsev | IOP2014: 100 TeV Collider7

“Known” Costs for 17 Machines

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• Actual– RHIC, MI, SNS, LHC

• Under construction– XFEL, FAIR, ESS

• Future– SSC, VLHC, NLC– ILC, TESLA, CLIC, Project-X,

Beta-Beam, SPL, ν-Factory

It is possible to parameterize the cost for known technologies

V.Shiltsev | IOP2014: 100 TeV Collider

Phenomenological Cost ModelCost(TPC)= α L1/2 + β E1/2 + γ P1/2

where α,β,γ – technology dependent constants– α≈ 2B$/sqrt(L/10 km)– β≈ 10B$/sqrt(E/TeV) for RF – β≈ 2B$/sqrt(E/ TeV) for SC magnets – β≈ 1B$ /sqrt(E/TeV) for NC magnets– γ≈ 2B$/sqrt(P/100 MW)

“Total Project Cost in the US accounting”

“Tunnel Length”Civil Construction

“Energy” – Cost ofAccelerator Components

“Site Power” Infrastructure

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Total Cost vs Model (Log-Log)

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The model is good to +-30%

Summary on the αβγ-Model

• Works with ~30% accuracy over wide range of parameters: – almost 3 orders of magnitude in L (length) from 0.5 km to 233 km– 4.5 orders of magnitude in E (energy) from 1 GeV to 40 Tev– more than 2 orders of magnitude in P (power) from few MW to 560MW

• With good certainty one may expact that the αβγ-model should give a decent estimate of TPC for any „green field“ facility which employs „known“ accelerator technologies (RF, magnets, tunnels, cryoplants and power infrastructure, etc)

• So, it was applied to all currently known/discussed ideas for future big accelerators:– SPL, Project X, DAEDALUS, μμ Higgs Factory, e-e+ Higgs Factories 16km to 80km, ν-

Factory, μμ Collider, +-e+ linear colliders (cold and warm, 0.5 TeV to 3 TeV), 40 TeV circular pp, 100 TeV circular p-p, 175TeV circular p-p, beam-plasma and beam-wakefield colliders (which use ”traditional” drive beams), etc, etc

• E.g., Future Circular Collider L=100km, E=100TeV p-p, P=400MW:

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TPC=2×(100/10)1/2+2×(100 TeV/1TeV)1/2+2×(400/100)1/2 =30B$ ±9B$• Once again, if you see much lower numbers, inquire whether that’s TPC

or “European accounting”, difference is usually x 2-2.5 if one does not account OH, R&D, PED, management, escalation, contingency, etc

The αβγ-Model Predictions• US alone can afford (within 2-4B$)

– Proton Driver (Project X)

• World’s Big Project possibilities– Higgs factory (“~ any type”)– may be Muon Collider or ILC-0.5 TeV

• What’s Beyond our limits (> 8-12B$)– >0.5 TeV e+e- collider (“~ any type”)– >30 TeV hadron (“~ any type”)

V.Shiltsev | IOP2014: 100 TeV Collider13

Far Future Colliders: “Phase-Space”• “Interesting Physics”

100-1000 TeV (10-100 × LHC) decent luminosity

• “Live within our means”: < 10 B$ < 10 km < 10 MW (beam power, ~100MW total)

V.Shiltsev | IOP2014: 100 TeV Collider

New technology should provide >10 GeV/m @ total component cost <1M$/m ( ~NC magnets now)

~ 50 MeV per meter

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Options: #1 Dielectric Structures

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Optical in Siλ=0.8 μmL=0.001 mdE ~0.00025 GeV 0.25 GeV/m

AWAATF

FACET

Beam driven in Diamond L~0.004-0.3 mdE ~few MeV ~0.1 GeV/m

Option #1: Dielectrics

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ISSUES AND QUESTIONS:Gradient <0.3-1 GeV/m – is NOT sufficient !

Staging is VERY inefficient – severe troubles with transfers and even lower average acceleration gradient

Cost is prohibitive: the αβγ-model TPC for a 3 TeV e+e- DWA collider concept (calls for 20 traditional 0.86 GeV pulsed e- linacs, ~20 km of tunnels , ~430MW of site power) 2×(20/10)1/2+20×8×(0.86GeV/1TeV)1/2+2×(430/100)1/2 =21.7B$ ±7B$ ... plus, cost of diel.structures = ?

Power MW: 430 for 3 TeV (est.) … for 10-100 TeV ?

Luminosity - unknown (many issues, dE/E)

NB - at >1 TeV electrons radiate!

JING C., ET AL, IPAC’13, pp. 1322

Idea- Tajima & Dawson, Phys. Rev. Lett. (1979) Plasma wave: electron density perturbation

Laser/beam pulse ~ p/c

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Option B:Short intense laser pulse

~1017cm-3, 30 GV/m, λp~100μm

Option A:Short intense e-/e+/p bunch

1018cm-3, 100 GV/m, λp~30μm

Option #2: Plasma Waves

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Option #2a: Plasma Wakes by BeamFACET

V.Shiltsev | IOP2014: 100 TeV Collider

n 5e16 cm-3∼L=0.3 mdE ~2 GeV 6 GeV/m

Plasma OFF Plasma ON

Option #2b: Plasma Wakes by LaserBELLALWA (UTA)

V.Shiltsev | IOP2014: 100 TeV Collider

n few e17 cm-3∼L=0.03-0.1 mdE ~2-5 GeV (PW lasers) > 30 GeV/m

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Option #2: Plasma Wakefields

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ISSUES AND QUESTIONS:Staging is VERY inefficient – limits average acceleration gradient to ~1-2 GeV/m (beam) and ~10 GeV/m (laser)

Cost is prohibitive (now) : e.g., in the beam-option (A) the αβγ-model estimate the cost of 10 TeV facility (25 GeV SCRF drive-beam, 20 km of tunnels, 540 MW) as 2×(20/10)1/2+ 10×(25GeV/1TeV)1/2+2×(540/100)1/2 =9B$ + 30-70% for plasma cells (?).... - for laser-plasma ~15-30 M$/10 GeV (i.e. factor of ~20 above required)

Power MW: 130 for 1 TeV –> 540 for 10 TeV (est.)

Luminosity - unknown (many issues, dE/E)

NB - at >1 TeV electrons radiate!

Leemans & Esarey, Physics Today (03/2009)

ADLI

E.,

ET A

L, a

rXiv

:130

8.11

45 (

2013

).

Option #3: Crystals & Muons

V.Shiltsev | IOP2014: 100 TeV Collider

1 PeV = 1000 TeVn ~1000

nB ~100frep ~106

L ~1030-32

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hys.

Usp

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55

965

(201

2)n~1022 cm-3, 10 TeV/m

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Option #3: Crystals & Muons

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ISSUES AND QUESTIONS:Can do(??) ~100+ GeV/m (test at ASTA)

- How to excite crystal? - Xrays? Sub-μm short bunches?

Cost/m unknown

Power MW: unknown

Luminosity - unknown (low)

yes – That will be the shortest accelerator

yes - Energy reach of 1-10 PeV thinkable

yes - Muons do not radiate !!

New Paradigm for Collider Physics

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Size is limited <10 km calls for thehighest gradients crystals muons

Luminosity calls for more par-ticles in the smallest beam size

This is the smallest beam size

The power is limited <10MW N is small at high E L

V.Shiltsev | IOP2014: 100 TeV Collider

Paradigm Shift : Energy vs Luminosity

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Summary

V.Shiltsev | IOP2014: 100 TeV Collider

• Success of Colliders : 29 built over 50 yrs, ~10 TeV c.m.e.

• The progress has greatly slowed down due to increasing size, complexity and cost of the facilities. The prospects for the next 20 years depend on the LHC discoveries.

• Reality sets constraints on the far-future colliders: <10B$, <10 km, <100MW

• There is (at least one) conceivable possibility to reach 100-1000 TeV c.m.e. within these limits (in far future).

• At least three paradigm shifts are needed: – development of the new technology based on

ultrahigh gradients ~0.1-10 TeV/m in, e.g., plasma or crystals;

– acceleration of heavier particles, preferably, muons;

– new approaches to physics research with luminosity limited to ~1030-32 cm-2s-1.

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