Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · physics/0008067

An injector for the CLIC test Facility (CTF3)

L. Rinolfi·H. Braun·R. Pittin·F. Zhou·B. Mouton·R. Miller·D. Yeremian
View original source ↗Read source document ↗Export metadata ↓

Abstract

The CLIC Test Facility (CTF3) is an intermediate step to demonstrate the technical feasibility of the key concepts of the new RF power source for CLIC. CTF3 will use electron beams with an energy range adjustable from 170 MeV (3.5 A) to 380 MeV (with low current). The injector is based on a thermionic gun followed by a classical bunching system embedded in a long solenoidal field. As an alternative, an RF photo-injector is also being studied. The beam dynamics studies on how to reach the stringent beam parameters at the exit of the injector are presented. Simulations performed with the EGUN code showed that a current of 7 A can be obtained with an emittance less than 10 mm.mrad at the gun exit. PARMELA results are presented and compared to the requested beam performance at the injector exit. Sub-Harmonic Bunchers (SHB) are foreseen, to switch the phase of the bunch trains by 180 degrees from even to odd RF buckets. Specific issues of the thermionic gun and of the SHB with fast phase switch are discussed.

Explore related subjects

physics.acc-ph

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

L. Rinolfi, H. Braun, R. Pittin, F. Zhou, B. Mouton, R. Miller, D. Yeremian. 2000-08-15. An injector for the CLIC test Facility (CTF3). https://arxiv.org/abs/physics/0008067

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↗