Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · physics/0209061

A Multi-Moded RF Delay Line Distribution System for the Next Linear Collider

S. G. Tantawi·C. Nantista·N. Kroll·Z. Li·R. Miller·R. Ruth·P. Wilson·J. Neilson
View original source ↗Read source document ↗Export metadata ↓

Abstract

The Delay Line Distribution System (DLDS) is an alternative to conventional pulse compression, which enhances the peak power of rf sources while matching the long pulse of those sources to the shorter filling time of accelerator structures. We present an implementation of this scheme that combines pairs of parallel delay lines of the system into single lines. The power of several sources is combined into a single waveguide delay line using a multi-mode launcher. The output mode of the launcher is determined by the phase coding of the input signals. The combined power is extracted from the delay line using mode-selective extractors, each of which extracts a single mode. Hence, the phase coding of the sources controls the output port of the combined power. The power is then fed to the local accelerator structures. We present a detailed design of such a system, including several implementation methods for the launchers, extractors, and ancillary high power rf components. The system is designed so that it can handle the 600 MW peak power required by the NLC design while maintaining high efficiency.

Explore related subjects

physics.acc-ph

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

S. G. Tantawi, C. Nantista, N. Kroll, Z. Li, R. Miller, R. Ruth, P. Wilson, J. Neilson. 2002-09-17. A Multi-Moded RF Delay Line Distribution System for the Next Linear Collider. https://doi.org/10.1103/physrevstab.5.032001

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

KEEP EXPLORING

Related papers

arXiv2026

Impedance of multilayer cylindrical structures with a material-filled beam region

Beam-coupling impedances in material media are relevant for ionization-cooling channels of a future muon collider, where the beam propagates in matter rather than vacuum. We extend the cylindrical field-matching formalism for multilayer structures to the case of a material-filled beam region surrounded by external layers with arbitrary electromagnetic properties. Relative to the vacuum formulation, the usual factor $1/γ^2$ is replaced by the material-dependent factor $F=1/\varepsilon_1-μ_1β^2$, and the radial propagation constant is modified accordingly. Analytical expressions are obtained for the monopolar longitudinal and dipolar transverse impedances, with the surrounding structure encoded through reflection coefficients determined by field matching. The formalism reduces to the known vacuum and perfectly conducting limits in the appropriate cases. Representative calculations are presented for absorber-relevant configurations, illustrating the dependence on the material properties of both the beam region and the surrounding layers. In particular, a finite beam-region conductivity can generate a real impedance component and reverse the sign of the imaginary space-charge impedance, while sufficiently high permittivity can give rise to resonant structures associated with oscillatory radial fields. The effect of finite-conductivity surroundings is also examined, showing the approach towards the perfectly conducting limit as the external conductivity is increased. The applicability of the infinite-length approximation is also discussed by comparison with finite-length mode-matching results.

physics.acc-ph↗
arXiv2026

Brilliance for adaptive computational research in accelerator physics

Computational research requires repeated decisions about models, calculations and the interpretation of results. We introduce Brilliance, an agent that combines large language models, reusable physics expertise and numerical simulation to construct and revise investigations in accelerator physics. Starting from a detailed expert-specified request, Brilliance develops an ideal storage-ring lattice meeting the specified emittance ceiling and sampled nonlinear-acceptance criteria after revising optics that fail particle-tracking tests. Further scientist-guided exploration produces a candidate with a natural emittance of 6.51 pm rad and millimeter-scale transverse acceptance, while exposing unresolved momentum-acceptance limitations. Using measured responses from the High Energy Photon Source, Brilliance also performs offline optics calibration consistent with an independent specialist analysis. An expert-module ablation examines how reusable domain knowledge influences research choices and outcomes. Here, we demonstrate a practical route to scientist-agent collaboration in sustained numerical research.

physics.acc-ph↗
arXiv2026

High-transformer-ratio plasma-based afterburner for extending X-ray free-electron laser photon energies to $\gtrsim$50 keV

Bright coherent X-rays in the $\gtrsim$50 keV range are highly desirable for applications in materials science, high-energy-density physics, and nuclear physics, but are difficult to obtain from present X-ray free-electron laser (XFEL) facilities. Plasma-based afterburners offer a compact route to increasing the electron-beam energy, yet high transformer ratio (TR) operation is vulnerable to hosing instability, which can severely degrade the witness beam quality. We propose using a transversely elliptical driver beam to excite an elliptical nonlinear plasma wake with an axially varying focusing gradient, thereby suppressing the witness beam hosing through betatron decoherence. Three-dimensional particle-in-cell simulations show that, for a 3 kA driver and a 2.35 kA witness beam with an rms length of 4 $\mathrmμ$m and a beam separation of 94 $\mathrmμ$m (TR $\approx 3$), this scheme can accelerate an 8 GeV witness beam to $\sim30$ GeV while nearly half of the electrons meet the XFEL requirements. Start-to-end simulations show that the resulting beam can drive $\gtrsim50$ keV XFEL radiation with peak powers of $\sim10$ GW and durations of $\sim10$ fs, even when quantum diffusion is included, offering a compact route to extend existing XFEL facilities to higher photon energies.

physics.acc-ph↗