arXiv subjects

N. Fuster-Martínez

Publications and source records attributed to N. Fuster-Martínez.

4 recordsLinked to original sources

arXiv2023

First Experimental Evidence of a Beam-Beam Long-Range Compensation Using Wires in the Large Hadron Collider

In high intensity and high energy colliders such as the CERN Large Hadron Collider and its future High Luminosity upgrade, interactions between the two beams around the different Interaction Points impose machine performance limitations. In fact, their effect reduces the beam lifetime and therefore the collider's luminosity reach. Those interactions are called Beam-Beam Long-Range interactions and a possible mitigation of their effect using DC wires was proposed for the first time in the early 2000's. This solution is currently being studied as an option for enhancing the HL-LHC performance. In 2017 and 2018, four demonstrators of wire compensators have been installed in the LHC. A two-year long experimental campaign followed in order to validate the possibility to mitigate the BBLR interactions in the LHC. During this campaign, a proof-of-concept was completed and motivated an additional set of experiments, successfully demonstrating the mitigation of BBLR interactions effects in beam conditions compatible with the operational configuration. This paper reports in detail the preparation of the experimental campaign, the obtained results and draws some perspectives for the future.

physics.acc-ph↗

arXiv2022

Novel reaction force for ultra-relativistic dynamics of a classical point charge

The problem of the electromagnetic radiation of an accelerated charged particle is one of the most controversial issues in Physics since the beginning of the last century, representing one of the most popular unsolved problems of the Modern Physics. Different equations of motion have been proposed throughout history for a point charge including the electromagnetic radiation emitted, but all these expressions show some limitations. An equation based on the principle of conservation of energy is proposed in this work for the ultra-relativistic motion. Different examples are analyzed showing that the energy lost by the charge agrees with the Liénard formula. This proposed equation has been compared with the Landau-Lifshitz equation obtaining a good agreement in the range of application of the Landau-Lifshitz formula.

physics.acc-ph↗

arXiv2021

Beam-based aperture measurements with movable collimator jaws as performance booster of the CERN Large Hadron Collider

The beam aperture of a particle accelerator defines the clearance available for the circulating beams and is a parameter of paramount importance for the accelerator performance. At the CERN Large Hadron Collider (LHC), the knowledge and control of the available aperture is crucial because the nominal proton beams carry an energy of 362 MJ stored in a superconducting environment. Even a tiny fraction of beam losses could quench the superconducting magnets or cause severe material damage. Furthermore, in a circular collider, the performance in terms of peak luminosity depends to a large extent on the aperture of the inner triplet quadrupoles, which are used to focus the beams at the interaction points. In the LHC, this aperture represents the smallest aperture at top-energy with squeezed beams and determines the maximum potential reach of the peak luminosity. Beam-based aperture measurements in these conditions are difficult and challenging. In this paper, we present different methods that have been developed over the years for precise beam-based aperture measurements in the LHC, highlighting applications and results that contributed to boost the operational LHC performance in Run 1 (2010-2013) and Run 2 (2015-2018).

physics.acc-ph↗

arXiv2020

Simulations of heavy-ion halo collimation at the CERN Large Hadron Collider: benchmark with measurements and cleaning performance evaluation

Protons and heavy-ion beams at unprecedented energies are brought into collisions in the CERN Large Hadron Collider for high-energy experiments. The LHC multi-stage collimation system is designed to provide protection against regular and abnormal losses in order to reduce the risk of quenches of the superconducting magnets as well as keeping background in the experiments under control. Compared to protons, beam collimation in the heavy-ion runs is more challenging despite the lower stored beam energies, because the efficiency of cleaning with heavy ions has been observed to be two orders of magnitude worse. This is due to the differences in the interaction mechanisms between the beams and the collimators. Ion beams experience fragmentation and electromagnetic dissociation at the collimators that result in a substantial flux of off-rigidity particles that escape the collimation system. These out-scattered nuclei might be lost around the ring, eventually imposing a limit on the maximum achievable stored beam energy. Accurate simulation tools are crucial in order to understand and control these losses. A new simulation framework has been developed for heavy-ion collimation based on the coupling of the Sixtrack tracking code and the FLUKA Monte Carlo code that models the electromagnetic and nuclear interactions of the heavy-ions with the nuclei of the collimator material. In this paper, the new simulation tool is described. Furthermore, Sixtrack-FLUKA coupling simulations are presented and compared with measurements done with Pb ions in the LHC. The agreement between simulations and measurements is discussed and the results are used to understand and optimise losses. The simulation tool is also applied to predict the performance of the collimation system for the High-Luminosity LHC.

physics.acc-ph↗