arXiv subjects

Jesús Rubayo-Soneira

Publications and source records attributed to Jesús Rubayo-Soneira.

3 recordsLinked to original sources

arXiv2026

Construction of crystal-based light sources with LWFA electron beams

We discuss a possibility to construct a crystal-based light source (CLS) of gamma-rays using electron beams produce by Laser Wake Field Acceleration (LWFA). This state-of-the-art acceleration technique is capable of producing few-GeV, ultra-short (fs) electron beams. In the case studies presented, we demonstrate the feasibility of novel gamma-ray CLSs based on exposing single crystals to electron beams available at the ELI-ELBA. The results of rigorous numerical simulations are presented to characterise the radiation emitted emitted by 1 and 4 GeV electrons incident on a 200-micron-thick single silicon crystal along the (110) plane. The simulations were performed using the current divergence as well as a smaller value that is believed to be a realistic to achieve in the near future. We demonstrate that it is feasible to achieve a photon yield of $10^6-10^7$ photons/s in the photon energy range from 5 to 50 MeV. Looking further ahead, we also performed a similar analysis for a 4-GeV positron beam incident on much thicker targets, up to 2 mm oriented silicon crystal. In this case, the photon yield can be increased by an order of magnitude.

physics.acc-ph↗

arXiv2023

Simulation of Deflection and Photon Emission of Ultra-Relativistic Electrons and Positrons in a Quasi-Mosaic Bent Silicon Crystal

A comprehensive numerical investigation has been conducted on the angular distribution and spectrum of radiation emitted by 855 MeV electron and positron beams while traversing a 'quasi-mosaic' bent silicon (111) crystal. This interaction of charged particles with a bent crystal gives rise to various phenomena such as channeling, dechanneling, volume reflection, and volume capture. The crystal's geometry, emittance of the collimated particle beams, as well as their alignment with respect to the crystal, have been taken into account as they are essential for an accurate quantitative description of the processes. The simulations have been performed using a specialized relativistic molecular dynamics module implemented in the MBN Explorer package. The angular distribution of the particles after traversing the crystal has been calculated for beams of different emittances as well as for different anticlastic curvatures of the bent crystals. For the electron beam, the angular distributions of the deflected particles and the spectrum of radiation obtained in the simulations are compared with the experimental data collected at the Mainz Microtron facility. For the positron beam such calculations have been performed for the first time. We predict significant differences in the angular distributions and the radiation spectra for positrons versus electrons.

physics.acc-ph↗

arXiv2012

Quasi-classical trajectories study of Ne2Br2(B) vibrational predissociation: Kinetics and product distributions

The vibrational predissociation of the Ne2Br2(B) van der Waals complex has been investigated using the quasi-classical trajectory method (QCT), in the range of vibrational levels v' = 16-23. Extensive comparison is made with the most recent experimental observations [Pio et al., J. Chem. Phys. 133, 014305 (2010)], molecular dynamics with quantum transitions (MDQT) simulations [Miguel et al., Faraday Discuss. 118, 257 (2001)], and preliminary results from 24-dimensional Cartesian coupled coherent state (CCCS) calculations. A sequential mechanism is found to accurately describe the theoretical dynamical evolution of intermediate and final product populations, and both QCT and CCCS provide very good estimates for the dissociation lifetimes. The capabilities of QCT in the description of the fragmentation kinetics is analyzed in detail by using reduced-dimensionality models of the complexes and concepts from phase-space transport theory. The problem of fast decoupling of the different coherent states in CCCS simulations, resulting from the high dimensionality of phase space, is tackled using a re-expansion scheme. QCT ro-vibrational product state distributions are reported. Due to the weakness of the vdW couplings and the low density of vibrational states, QCT predicts a larger than observed propensity for Δv' = -1 and -2 channels for the respective dissociation of the first and second Ne atoms.

physics.chem-ph↗