arXiv subjects

A. V. Vasyliev

Publications and source records attributed to A. V. Vasyliev.

6 recordsLinked to original sources

arXiv2026

Start-to-end simulations of non-relativistic electron acceleration along reflective grating structure by front-tilted laser pulse

A comprehensive (start-to-end) simulation was performed regarding the formation of a front-tilted laser pulse and the subsequent acceleration of non-relativistic electrons moving along a reflective grating structure. The laser pulse tilt was formed using another diffraction grating -- either reflective or transmissive. The pulse had a spectral range (FWHM) of 803--863 nm and an initial duration of approximately 17 fs. Acceleration under normal laser pulse incidence was also calculated for comparison. Research results indicate that the use of a femtosecond laser pulse with a front, tilted by means of a reflective diffraction grating, significantly enhances the efficiency of laser acceleration of non-relativistic electrons compared to the case of a pulse at normal incidence. Furthermore, it was found that using a transmissive diffraction grating to shape the tilted pulse front also increases acceleration efficiency relative to normal incidence on the accelerating grating, although the acceleration rate is lower than when a reflective diffraction grating is used.

physics.optics↗

arXiv2026

Electron energy gain in a dielectric laser accelerator as a function of the base angle of a triangular grating structure

Dielectric laser accelerators (DLAs) represent a compact and cost-effective alternative to conventional RF accelerators. Despite the various grating geometries already studied, a comprehensive investigation of triangular profiles, particularly the effect of the base angle of the saw-tooth grating profile, remains insufficient. This paper presents the results of numerical particle-in-cell (PIC) simulations of electron acceleration in DLAs based on double gratings with a triangular profile. One of the gratings, onto which the laser beam is incident, is transparent, while the second grating was either transparent or reflective for the laser pulse. The geometry of the first grating was fixed. A systematic study was conducted on the influence of the base angle of the second grating ($α= 5^\circ - 44^\circ$), its spatial orientation, the presence of a reflective gold coating, and the shape of the incident laser pulse (plane wave versus Gaussian profile) on the acceleration rate. The results reveal a complex interplay between these parameters. For an electron beam with an initial energy of 10 MeV, a maximum accelerating rate of 345 MeV/m was achieved for the structure with a left-handed reflective grating and a base angle of $α= 10^\circ$ when excited by a Gaussian pulse. Under plane-wave excitation, the left-handed reflective grating with $α= 25^\circ$ provided a rate of 325 MeV/m. It is shown that for single-bunch injection, nearly the maximum energy gain can be attained within a temporal window of 0.5 fs. The obtained results provide a quantitative basis for optimizing DLA designs with triangular gratings, highlighting the significant role of the saw-tooth profile base angle and the grating type in achieving high rates for next-generation accelerators.

physics.acc-ph↗

arXiv2025

A compact, easy-to-use leak detector for vacuum systems based on the MQ-8 sensor

This paper presents the development of a compact leak detector for vacuum systems that operates using hydrogen as a tracer gas, detected by a semiconductor MQ-8 sensor. The sensor is connected to an Arduino microcontroller, enabling digital signal processing and real-time visualization through the Processing software environment. The designed device is capable of detecting even small hydrogen leaks caused by imperfect sealing of vacuum connections. It is characterized by simplicity, low manufacturing cost, and suitability for laboratory use as an alternative to helium leak detectors. Experimental tests confirmed the effectiveness and stability of the developed leak detector during long-term measurements.

physics.ins-det↗

arXiv2025

Acceleration gradients in dielectric laser accelerators with triangular-shaped gratings

The study investigated transparent on-chip structures with a rectangular profile and triangular profiles with grating ridge base angles of $α= 36^\circ$, $30^\circ$, and $20^\circ$. Each triangular structure had both left- and right-handed profile orientations. For all variants, a modified version with a reflective gold coating was additionally considered. The maximum energy gains and accelerating gradients were determined and quantified for all structure classes: transparent and reflective (with both rectangular and triangular profiles).

physics.optics↗

arXiv2025

Prism-based compensation of group delay dispersion in the components of a femtosecond laser resonator and analysis of the influence of prism configuration on laser radiation parameters

A mathematical algorithm is described for calculating the minimum distance between prisms and the allowable prism insertion depth into the laser beam when solving the general problem of intracavity group delay dispersion (GDD) compensation. GDD is caused by the optical elements of the master oscillator in a femtosecond laser system. The calculation was carried out using analytical and geometrical methods. The influence of changing the distance between the prisms and the depth of their insertion into the laser beam on the GDD compensation has been investigated. Under experimental conditions, this changes the Q-factor of the laser resonator, which determines the central wavelength of the radiation and its spectral width in a titanium-sapphire laser.

physics.optics↗

arXiv2024

Comparative Analysis of Simulation Results of Dielectric Laser Acceleration of Non-relativistic Electrons in Transparent and Reflective Periodic Structures

To support of our experimental studies on dielectric laser acceleration, numerical studies of laser acceleration of nonrelativistic electrons with the initial energy of 33.9 keV in transparent and reflective periodic structures are car-ried out. On the basis of computer simulations, the acceleration rates of electrons and the quality of their beams after acceleration in compact structures of different configurations were determined and compared. Prospective acceleration schemes are proposed, in particular with reflective periodic structures, which can provide higher rates of electron acceleration in periodic structures than in previously obtained studies.

physics.acc-ph↗