New proposal:
Laser Control and Collimation of Particle Beams for Higgs Factories
Spencer Gessner, SLAC
FACET-II PAC Meeting
November 20, 2024
Facility for Advanced Accelerator Experimental Tests
Proposal Team
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S. Gessner, M. Hogan, A. Knetsch, B. O’Shea, T. Raubenheimer, D. Reis
S. Meuren
J. Keintzel, F. Zimmermann
N. T. Hod
I. Drebot
Collimation for Circular Colliders
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Collimation of particle beams is a major challenge for high-luminosity colliders.
The challenges related to the collimator, which were not properly considered at the time of SuperKEKB design, have surfaced through experience with its operation.
Collimator design is critical to achieving the luminosity goals of a collider.
Collimation for Circular Colliders
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Collimation of particle beams is a major challenge for high-luminosity colliders.
The challenges related to the collimator, which were not properly considered at the time of SuperKEKB design, have surfaced through experience with its operation.
Collimator design is critical to achieving the luminosity goals of a collider.
Collimation for Linear Colliders
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Collimation of particle beams dominates the length of the Beam Delivery System.
Novel collimation schemes will reduce cost of a Linear Collider Higgs Factory and enable a 10 TeV Wakefield Collider.
ILC BDS: 1 km of collimation!
Barklow, Gessner et. al. “Beam delivery and beamstrahlung considerations for ultra-high energy linear colliders” JINST 18 P09022 (2023)
The Beam-Beam Flip-Flop Instability
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Asymmetric scenario:
N = N0 + Δ
nγBS ↑
σz = σz0
ξ = ξ0
N = N0 - Δ
nγBS ↓
σz = σz0
ξ = ξ0
Weak
Strong
The Beam-Beam Flip-Flop Instability
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Asymmetric scenario:
N = N0 + Δ
nγBS ↑
σz ↓
ξ ↓
N = N0 - Δ
nγBS ↓
σz ↑
ξ ↑
Weak
Strong
ξy may become very large for the weak beam. Charge and luminosity are lost.
Beam-Beam Instabilities in the FCC-ee
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D. Shatilov https://doi.org/10.1140/epjp/s13360-022-02346-x
K. Nguyen et al. https://arxiv.org/abs/2404.09012
Simulations indicate that the growth rate of the instability over ~10000 turns.
At the z-pole, a few percent intensity asymmetry is tolerable.
Asymmetries are balanced through top-up injection.
But the top-up rate is slower than the instability growth rate.
Is there a faster way to control the charge of the colliding bunches?
Science Drivers
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Proposal: Laser Control of Particle Beams
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Zimmerman, F. New final focus concepts at 5 TeV and beyond. Eighth Advanced Accelerator Concepts Workshop. 1998.
F. Zimmermann, T. Raubenheimer IPAC 2022 https://accelconf.web.cern.ch/ipac2022/papers/wepost010.pdf
I. Drebot, et. al IPAC 2023 https://doi.org/10.18429/JACoW-IPAC2023-MOPA074
Laser collimation of Particle Beams for Multi-TeV Linear Collider
Shot-by-shot control of electron bunch intensity in FCC.
“A Ti:sapphire J-class kHz laser system is ready to be built today [7–9]. Specifically, we consider a laser system operating with 1 J pulses at 3 kHz (the revolution frequency), with an average power of 3 kW, which translates to the same average laser power as for LBNL’s k-BELLA initiative (3 J at 1 kHz) [10].”
E320 is the backbone of this proposal
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Leverage the E320 infrastructure at FACET-II to provide an R&D platform for:
FACET-II is the only User Facility in the world that combines 10 GeV beams with high-power lasers to accommodate this type of R&D.
Linear Compton Scattering
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Much of this R&D assumes Linear Compton Scattering.
We prefer long electron beams and stretched laser pulses (σz = 200 μm, σt = 0.66 ps)
Assume 100 mJ laser pulse energy.
The expected cross-section is 550 millibarn.
There are approximately 4 ✕ 1017 photons per pulse.
The interaction probability is 10-3 - 10-2 depending on geometry.
Phase 1: Demonstration of a fast feed-forward system
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Goals:
Hardware:
Expected signal:
I. Drebot, et. al IPAC 2023 https://doi.org/10.18429/JACoW-IPAC2023-MOPA074
M. Turner, et. al Phys. Rev. Lett. 122, 054801 (2019)
Phase 2: Halo Collimation
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Goals:
Hardware:
Expected signal:
Gessner, S. et al. Demonstration of a positron beam-driven hollow channel plasma wakefield accelerator. Nat. Comm. 2016.
LBG_LFOV upgrade (Knetsch)
Phase 3: Alternative Schemes
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Goals:
Hardware:
Expected signal:
Tilted Phase Front
Cylindrical Lens
Nonlinear Quenched Regime
Operate in a nonlinear regime but still induce a binary interaction.
“Quantum Quenching of Radiation Losses in Short Laser Pulses.” C. N. Harvey, et al. Phys. Rev. Lett. 118, 105004 (2017)
Conclusions
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The R&D topics covered by this proposal have the potential to improve the performance and reduce the cost of future Higgs Factories, while paving the way towards a 10 TeV Wakefield Collider BDS system.
The E320 experiment enables rapid implementation and a clear path to results for this proposal.
The implementation of a Halo Monitor will be broadly useful for the facility.