Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 2610.07322

Limits on energy recovery for positron acceleration in a warm plasma column

Max Varverakis·Spencer Gessner·Severin Diederichs·Carl A. Lindstrøm
View original source ↗Read source document ↗Export metadata ↓

Abstract

Beam-driven plasma wakefield acceleration (PWFA) is a promising candidate for realizing a future linear collider, owing to the extremely high field gradients that are produced in plasmas. Despite recent success in high-gradient and high-efficiency electron PWFA, efficient positron PWFA remains a challenge. The warm plasma column regime offers stable, high-quality acceleration of positron beams in a plasma electron filament, albeit at low energy-transfer efficiencies. We explore the possibility of employing an electron energy recovery beam to extract residual energy from the plasma wakefield and increase the efficiency of this scheme. Our particle-in-cell simulations reveal that certain mechanisms, including higher-order ionization and ion motion, limit our ability to further extract energy from the plasma wakefield.

Explore related subjects

physics.acc-phphysics.plasm-ph

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Max Varverakis, Spencer Gessner, Severin Diederichs, Carl A. Lindstrøm. 2026-10-05. Limits on energy recovery for positron acceleration in a warm plasma column. https://arxiv.org/abs/2610.07322

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

A modern particle-in-cell code for beam-beam simulations of future colliders

A key challenge in the design of next-generation colliders is predicting the effects of beam-beam interactions and using these predictions to optimize machine performance. Beam-beam interactions are characterized by strong focusing forces, radiative effects, and the generation of background particles. While analytical formulas provide insight into the dynamics of beam-beam interactions, these nonlinear, coupled effects are most accurately described with numerical methods. In this paper, we introduce the open-source particle-in-cell code WarpX as a modern tool for modeling the interaction point in future lepton colliders. WarpX provides high-performance execution on distributed GPU architectures within an open-source and actively maintained code base. We present convergence scans and benchmarks against the established beam-beam codes GUINEA-PIG (v1.2.2) and CAIN (v2.42) for luminosity spectra, photon emission, and secondary-particle production under a wide range of beam parameters corresponding to different collider concepts. Our results show that WarpX (v26.09) reproduces the benchmark beam-beam observables while enabling GPU-portable, extensible simulations. These results establish WarpX as a scalable platform for high-fidelity beam-beam modeling in future collider studies.

physics.acc-ph↗
arXiv2026

Phase Memory Controls Radiative Depolarization Near an Isolated Spin Resonance

Radiative depolarization near spin resonances in electron storage rings is conventionally described by correlated-sideband and local resonance-density theories, but a quantitative description of the crossover between them has remained lacking. Here we derive a unified finite-memory response from stochastic spin dynamics near an isolated resonance. By separating the coherent resonance contribution from stochastic fluctuations, we show that the connected correlation of the accumulated resonance-relative spin phase determines the leading off-center weak-resonance depolarization rate. Both conventional theories emerge as controlled asymptotic limits of this response, which also captures the surviving synchrotron phase memory governing the crossover. Monte Carlo spin tracking validates the predicted rates throughout the crossover and reproduces the recurrence-induced generalized-sideband structure. More broadly, the connected-correlation formulation provides a basis for extending radiative depolarization theory to more general stochastic spin-orbit dynamics in storage rings.

physics.acc-ph↗
arXiv2026

Anomaly Detection in Bunch Oscillations for Early Warning of Sudden Beam Loss at SuperKEKB

Sudden beam loss (SBL) events at the SuperKEKB collider result in the loss of a large fraction of the stored beam within just a few revolutions, on a timescale comparable to or shorter than the 20-30 μs latency of the existing abort system. Such events have damaged collimators and threaten Belle II subdetectors. Bunch Oscillation Recorders (BORs) capture transverse bunch positions at each revolution, which often show sizable oscillations that precede significant beam current loss. We test whether these precursors can be detected earlier than a charge-based reference that mimics the existing abort sensors. We apply several oscillation-based anomaly detection algorithms to 208 SBL events recorded in the low-energy ring during the 2024 run period, ranging from simple rolling statistics to machine learning models trained to forecast bunch oscillation. On 173 events not used for training or calibration, the best-balanced model (DeepLSTM) triggers before the charge-based reference in 86-90% of events across five training seeds, with a mean lead time of 25-30 μs. The only trigger classified as a false alarm fires on an oscillation that begins about 60 turns before the abort and persists until the beam is lost, making it more likely an early precursor than a spurious trigger. These results establish bunch oscillations as a viable early abort trigger and motivate a shadow-mode deployment to measure the false-alarm rate in continuous operation.

physics.acc-ph↗