arXiv subjects

Emmanouil Kaniolakis-Kaloudis

Publications and source records attributed to Emmanouil Kaniolakis-Kaloudis.

2 recordsLinked to original sources

arXiv2025

Precise control of high-frequency ultrasounds in thin crystals for the development of tunable narrowband and directional gamma-ray sources

This work presents a complete methodology for the precise characterization of the acoustic field inside crystal-based devices driven by high-frequency ultrasounds towards the generation of tunable narrowband and directional gamma radiation via undulation of ultra-relativistic charged particles. Such gamma-ray sources have long been anticipated by the scientific community, as they promise new powerful tools for the study of high-energy physical phenomena and the development of novel nuclear technologies. In such devices, a piezoelectric transducer induces tens of MHz harmonic waves inside a silicon monocrystal. Ultra-relativistic charged particles traversing the crystal get trapped within the channels formed by the extremely strong electric fields of the acoustically modulated lattice planes, undergoing undulation and emitting gamma radiation. Precise characterization of the acoustic field in the crystal is crucial for the determination of the expected characteristics of the secondarily generated gamma rays. For this purpose, fast laser refraction imaging is used here to image the acoustic waves by exploiting the spatial redistribution of a laser beam optical intensity caused by the acoustic field. A dedicated computational model is developed for the estimation of the spatial distribution of the pressure and lattice deformation inside the crystal. This methodology provides a framework for future novel gamma-ray sources in high-energy facilities.

physics.acc-ph↗

arXiv2024

Narrowband gamma-ray radiation generation by acoustically driven crystalline undulators

In this paper we present a novel scheme for the controlled generation of of tunable narrowband gamma-ray radiation by ultra-relativistic positron beams inside acoustically driven periodically bent crystals. A novel acoustic crystalline undulator is presented, in which excitation of a silicon single crystal along the (100) planar direction by a piezoelectric transducer periodically modulates the crystal lattice in the [100] axial direction. An ultra-relativistic positron beam is directed diagonally into the crystal and propagates along the (110) planes. The lattice modulation forces the positrons to follow periodic trajectories,resulting in the emission of undulator radiation in the MeV range. A computational methodology for the design and development of such acoustically based light sources is presented together with the results of simulations demonstrating the favourable properties of the proposed technology. The longitudinal acoustic strains induced in the crystal by high-frequency piezoelectric elements are calculated by finite element simulations. The resulting bending profiles of the deformed crystal planes are used as geometrical conditions in the relativistic molecular dynamics simulations that calculate the positron trajectories and the spectral distribution of the emitted radiation. The results show a strong enhancement of the emitted radiation within a narrow spectral band defined by the bending period, demonstrating the feasibility and potential of the proposed technology.

physics.acc-ph↗