arXiv subjects

G. Franchetti

Publications and source records attributed to G. Franchetti.

6 recordsLinked to original sources

arXiv2026

Proof-of-principle experiment of a novel beam extraction over millions of turns using stable resonance islands and bent crystal

A recent study [1] has introduced an advanced method aimed at extracting from a circular particle accelerator over millions of turns using stable islands and a bent crystal. This technique leverages the strength of non-linear beam dynamics along with adiabatic trapping and transport within stable islands, in combination with a bent silicon crystal, to provide an efficient extraction of hadron beams over millions of turns. The positive and encouraging results of the comprehensive numerical simulations were validated through a successful proof-of-principle experiment at the CERN Super Proton Synchrotron, which demonstrated the feasibility of the technique. This paper presents a detailed discussion and analysis of the experimental results.

physics.acc-ph↗

arXiv2024

Exploring the Potential of Resonance Islands and Bent Crystals for a Novel Slow Extraction from Circular Hadron Accelerators

New developments in accelerator physics have broadened the set of available techniques for manipulating charged-particle beams. Adiabatic trapping and transport of beam in resonance islands has been studied and successfully implemented at the CERN Proton Synchrotron to perform multiturn extraction. Bent crystals have been successfully installed in the CERN Large Hadron Collider, improving the cleaning performance of the collimation system, and at the CERN Super Proton Synchrotron for reducing losses at the extraction septum in the case of slow extraction. In this paper, we discuss the potential of the combined use of resonance islands and bent crystals to devise a novel technique to perform slow extraction in circular hadron accelerators. The proposed approach is promising, particularly for applications with high-intensity beams, as it could dramatically reduce the losses on the extraction devices.

physics.acc-ph↗

arXiv2024

Harmonic analysis of non-stationary signals with application to LHC beam measurements

Harmonic analysis has provided powerful tools to accurately determine the tune from turn-by-turn data originating from numerical simulations or beam measurements in circular accelerators and storage rings. Methods that have been developed since the 1990s are suitable for stationary signals, i.e., time series whose properties do not vary with time and are represented by stationary signals. However, it is common experience that accelerator physics is a rich source of time series in which the signal amplitude varies over time. Furthermore, the properties of the amplitude variation of the signal often contain essential information about the phenomena under consideration. In this paper, a novel approach is presented, suitable for determining the tune of a non-stationary signal, which is based on the use of the Hilbert transform. The accuracy of the proposed methods is assessed in detail, and an application to the analysis of beam data collected at the CERN Large Hadron Collider is presented and discussed in detail.

physics.acc-ph↗

arXiv2022

Measurement of transverse beam emittance of split beams for the CERN Proton Synchrotron Multi-Turn Extraction

Crossing a horizontal nonlinear resonance is the approach that can be used to split a beam in several beamlets with the goal to perform multi-turn extraction from a circular particle accelerator. Such an approach has been successfully implemented in the CERN Proton Synchrotron and is used routinely for the production of high-intensity proton beams for fixed-target physics at the Super Proton Synchrotron. Recently, thanks to the deployment of diamond detectors, originally installed to monitor the beam losses at extraction, it has been possible to measure the horizontal beam emittance of the split beam just prior to extraction. This is the first time that an emittance measurement is attempted for split beams, i.e. in a regime of highly nonlinear beam dynamics. In this paper, the technique is presented and its application to the analysis of the experimental data is presented and discussed in detail. This result is essential for the performance assessment of the splitting process and for the design of further performance improvements.

physics.acc-ph↗

arXiv2021

Storage Rings and Gravitational Waves: Summary and Outlook

We report some highlights from the ARIES APEC workshop on ``Storage Rings and Gravitational Waves'' (SRGW2021), held in virtual space from 2 February to 18 March 2021, and sketch a tentative landscape for using accelerators and associated technologies for the detection or generation of gravitational waves.

physics.acc-ph↗

arXiv2000

Phase Rotation, Cooling And Acceleration Of Muon Beams: A Comparison Of Different Approaches

Experimental and theoretical activities are underway at CERN with the aim of examining the feasibility of a very-high-flux neutrino source. In the present scheme, a high-power proton beam (some 4 MW) bombards a target where pions are produced. The pions are collected and decay to muons under controlled optical condition. The muons are cooled and accelerated to a final energy of 50 GeV before being injected into a decay ring where they decay under well-defined conditions of energy and emittance. We present the most challenging parts of the whole scenario, the muon capture, the ionisation-cooling and the first stage of the muon acceleration. Different schemes, their performance and the technical challenges are compared.

physics.acc-ph↗