Synergies for Near-Term Colliders and Advanced Accelerator R&D

Spencer Gessner

SLAC National Accelerator Laboratory

AAC WG7

July 27, 2026

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Advanced Accelerator R&D and Near-Term Colliders

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Advanced Accelerator R&D

• Blue sky - consider all possibilities
• Invention of new methods
• Failure is ok
• Publications are a measure of success.

Near-Term Colliders

• Shovel-ready
• Established methods
• Low technical risk
• “We publish in concrete and steel” - Sir John Adams

Advanced Accelerator R&D and Near-Term Colliders

3

Advanced Accelerator R&D

• Blue sky - consider all possibilities
• Invention of new methods
• Failure is ok
• Publications are a measure of success.

Near-Term Colliders

• Shovel-ready
• Established methods
• Low technical risk
• “We publish in concrete and steel” - Sir John Adams

Are there opportunities for AAC concepts to make an impact on near-term collider projects?

Colliders of the future

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EIC @ BNL

FCC @ CERN

Linear Collider

Wakefield Collider

Muon Collider

Colliders of the future

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EIC @ BNL

FCC @ CERN

Linear Collider

Wakefield Collider

Muon Collider

How can AAC make an impact?

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DON’T ask “How can we add a plasma accelerator to your collider?”

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DO ask “What are the challenges for your project?”

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Beam Physics Challenges for EIC

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• Generation and acceleration of polarized electron beams.

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• Preservation of electron beam polarization in the injector chain.

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• Preservation of electron beam polarization in the collider ring.

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• Beam-beam effects on hadron beam emittance.

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• Impedance effects.

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• Swap-out injection.

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• Collimation.

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• High-energy hadron cooling.

Beam Physics Challenges for EIC

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• Generation and acceleration of polarized electron beams.

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• Preservation of electron beam polarization in the injector chain.

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• Preservation of electron beam polarization in the collider ring.

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• Beam-beam effects on hadron beam emittance.

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• Impedance effects.

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• Swap-out injection.

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• Collimation.

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• High-energy hadron cooling.

Opportunity for AAC modeling tools

• WarpX for beam-beam (Arianna Formenti)
• Material wakefield calculations

Beam Physics Challenges for EIC

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• Generation and acceleration of polarized electron beams.

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• Preservation of electron beam polarization in the injector chain.

​

• Preservation of electron beam polarization in the collider ring.

​

• Beam-beam effects on hadron beam emittance.

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• Impedance effects.

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• Swap-out injection.

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• Collimation.

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• High-energy hadron cooling.

Opportunity for AAC methods

• Laser collimation (Ching-En Lin)
• Beam dynamics and microbunching

Beam Physics Challenges for FCC

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• Generation and acceleration of electron beams with dynamic charge.

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• Beam-beam limitations and detector backgrounds.

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• Impedance effects.

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• Electron cloud effects.

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• Top-up injection.

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• Collimation.

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• Intensity control with Compton Backscatter.

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Beam Physics Challenges for FCC

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• Generation and acceleration of electron beams with dynamic charge.

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• Beam-beam limitations and detector backgrounds.

​

• Impedance effects.

​

• Electron cloud effects.

​

• Top-up injection.

​

• Collimation.

​

• Intensity control with Compton Backscatter.

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Opportunity for AAC facilities

• Emittance preservation studies at FACET (Brendan O’Shea)
• Shot-to-shot charge variation at the photocathode.

Beam Physics Challenges for FCC

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• Generation and acceleration of electron beams with dynamic charge.

​

• Beam-beam limitations and detector backgrounds.

​

• Impedance effects.

​

• Electron cloud effects.

​

• Top-up injection.

​

• Collimation.

​

• Intensity control with Compton Backscatter.

​

Opportunity for AAC modeling tools

• WarpX for beam-beam
• Material wakefield calculations
• PIC for electron cloud studies

Beam Physics Challenges for FCC

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• Generation and acceleration of electron beams with dynamic charge.

​

• Beam-beam limitations and detector backgrounds.

​

• Impedance effects.

​

• Electron cloud effects.

​

• Top-up injection.

​

• Collimation.

​

• Intensity control with Compton Backscatter.

​

Opportunity for AAC methods

• Laser collimation (Ching-En Lin)
• Pulse-by-pulse Compton scattering with Joule-class laser.

Laser Control of Beam Intensity at FCC

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F. Zimmermann, T. Raubenheimer IPAC 2022 https://accelconf.web.cern.ch/ipac2022/papers/wepost010.pdf

A beam-beam flip-flop instability occurs when colliding bunches have asymmetric charge-per-bunch.

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If the instability grows faster than the top-up rate, a new method must be used to control bunch charge.

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Zimmermann and Raubenheimer proposed a charge feedback system based on Compton backscatting.

We are executing a proof-of-concept demonstration at FACET using the E320 experimental platform.

Experimental layout and AWAKE-style beam halo monitor.

https://doi.org/10.1140/epjp/s13360-026-07754-x

FCC Injector R&D @ FACET-II

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S. Bettoni, PSI

A. Latina, CERN

B. O’Shea, SLAC

Deploying WarpX Beam-Beam to the HEP Community

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Deploying WarpX Beam-Beam to the HEP Community

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FCC-ee beam-beam particle trajectories in WarpX (A. Formenti, LBNL)

Conclusion

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• The AAC community has developed novel technologies and techniques that may benefit near-term projects.

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• We must be honest about technical risks when presenting the upside of new ideas for reducing collider costs and improving collider performance.

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• The leaders of upcoming collider projects need our help! There are excellent examples of AAC contributions in this session:
• Laser-based collimation, Ching-En Lin, SLAC/Stanford
• Self-consistent simulations of colliders, Arianna Formenti, LBNL

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• Their support and endorsement will benefit the AAC community in the long-term when HEP is ready to support accelerator R&D.

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