Design of an interaction region with head-on collisions for the ILC

R. Appleby; D. Angal-Kalinin; F. Jackson; M . Alabau-Pons; P. Bambade; J. Brossard; O. Dadoun; C. Rimbault; L. Keller; Y. Nosochkov; A. Seryi; J. Payet; O. Napoly; C. Rippon; D. Uriot

arXiv · physics/0609248

Design of an interaction region with head-on collisions for the ILC

R. Appleby·D. Angal-Kalinin·F. Jackson·M . Alabau-Pons·P. Bambade·J. Brossard·O. Dadoun·C. Rimbault·L. Keller·Y. Nosochkov·A. Seryi·J. Payet·O. Napoly·C. Rippon·D. Uriot

View original source ↗Read source document ↗Export metadata ↓

Abstract

An interaction region (IR) with head-on collisions is considered as an alternative to the baseline configuration of the International Linear Collider (ILC) which includes two IRs with finite crossing-angles (2 and 20 mrad). Although more challenging for the beam extraction, the head-on scheme is favoured by the experiments because it allows a more convenient detector configuration, particularly in the forward region. The optics of the head-on extraction is revisited by separating the e+ and e- beams horizontally, first by electrostatic separators operated at their LEP nominal field and then using a defocusing quadrupole of the final focus beam line. In this way the septum magnet is protected from the beamstrahlung power. Newly optimized final focus and extraction optics are presented, including a first look at post-collision diagnostics. The influence of parasitic collisions is shown to lead to a region of stable collision parameters. Disrupted beam and beamstrahlung photon losses are calculated along the extraction elements.

Explore related subjects

physics.acc-ph

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

R. Appleby, D. Angal-Kalinin, F. Jackson, M . Alabau-Pons, P. Bambade, J. Brossard, O. Dadoun, C. Rimbault, L. Keller, Y. Nosochkov, A. Seryi, J. Payet, O. Napoly, C. Rippon, D. Uriot. 2006-09-28. Design of an interaction region with head-on collisions for the ILC. https://arxiv.org/abs/physics/0609248

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

KEEP EXPLORING

Related papers

arXiv2026

Phase-Space Shaping due to Betatron Cooling in Wakefield Accelerators and the Onset of the Ion-Channel Laser

Plasma-based accelerators are beginning to employ relativistic beams with unprecedented charge and ultrashort durations. These dense driver beams can drive wakes even in high-density plasmas ($\gtrsim10^{19}$ cm$^{-3}$), where betatron radiation becomes increasingly important and begins to affect the dynamics of the accelerated beam. We show that betatron cooling leads to a strong structuring of the phase space of the beam. This gives rise to bunched, ring-like structures with positive radial position and momentum gradients, \emph{i.e.}, population inversion of the amplitude of oscillation. We derive the characteristic timescales for this process analytically and confirm our predictions with multi-dimensional Particle-in-Cell simulations. The radiation-dominated regime of beam dynamics fundamentally alters the acceleration process and produces self-structured beams\reviewtwo{; Particle-in-Cell simulations of the resulting beams show that it becomes unstable to the ion-channel laser and lead to exponential amplification of radiation.

physics.acc-ph↗

arXiv2026

Brilliance: toward autonomous computational research in particle accelerator physics

Computational research in physics requires continuous interplay between simulation and scientific interpretation, demanding substantial specialist effort. Here we introduce Brilliance, a research agent that combines large language models, reusable physics knowledge and numerical simulation to conduct adaptive investigations in accelerator physics. Given a single user prompt, Brilliance designs a fourth-generation synchrotron light source that meets coupled emittance and nonlinear-acceptance requirements. Further exploration yields a design combining sub-10-pm emittance with a large dynamic aperture under realistic engineering constraints, suggesting a route towards hard-X-ray diffraction-limited operation, although the momentum-acceptance target remains unmet. Brilliance also calibrates a model of an operating light source against measured responses, accurately inferring its lattice and calibration errors. Across these studies, Brilliance autonomously revises its computational strategies in response to numerical evidence. These results demonstrate a route towards delegating sustained scientific investigations to agents equipped with domain expertise and numerical tools.

physics.acc-ph↗

arXiv2026

Intrabeam scattering of chirped electron bunches with non-Gaussian longitudinal distributions and slice mismatch

Intrabeam scattering (IBS) can significantly increase the uncorrelated energy spread of high-brightness electron bunches in linear accelerators. For chirped bunches transported through beamlines with dispersion, however, the commonly used simulation codes elegant and RF-Track give substantially different predictions. To investigate this discrepancy, a semi-analytical slice model is developed for bunches with non-Gaussian longitudinal distributions and slice-dependent transverse mismatch. The model predicts slice energy-spread evolution in beamlines with dispersion and provides an independent reference for assessing the simulation results. Benchmarks in an achromatic arc show good agreement with RF-Track for both ideal Gaussian and realistic mismatched bunches in the tested cases. The proposed model provides a practical tool for evaluating IBS in linacs beyond the ideal-Gaussian approximation. The comparison also suggests directions for improving the accuracy and efficiency of PIC-based IBS simulations.

physics.acc-ph↗