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In this paper, two parameters of the applied magnetic field—magnetic field strength and pulse length—are modified, the spatial properties of electron trajectories and radiation are studied, and conclusions are drawn. Under the premise that the radius of the laser pulse waist b 0 = 4 λ 0 , and that the peak amplitude a 0 = 5 corresponds to the peak laser intensity I L = 3.45 × 10 19   W / c m 2 of the electrons, obtaining high-energy and highly collimated X-rays can be realized by increasing the pulse length up to 6 λ 0 and increasing the magnitude of the applied magnetic field, or by continuously increasing the pulse length and applying a smaller magnetic field. [ABSTRACT FROM AUTHOR]

Based on the classical theory of nonlinear Thomson scattering and the single electron model, we performed extensive numerical simulations in MATLAB R2022b to comprehensively investigate how the initial phase of a tightly focused, circularly polarized laser pulse affects the radiation characteristics of high-energy electrons at different energy levels. Our findings indicate that the polar angle corresponding to the maximum radiation energy remains constant as the initial phase of the laser changes from 0 to 2π, while the azimuth angle correspondingly moves from 0 to 2π. Moreover, as the initial phase changes, the pulse width of the electron radiation peak displays a quasi-periodic oscillation with a period of π. Notably, an increase in the initial energy of the electrons results in a significant enhancement in both the peak radiation value and the collimation of the radiation. These results demonstrate that manipulating the initial phase of the driving laser pulse enables effective control over the spatial distribution of radiation light. [ABSTRACT FROM AUTHOR]

A universal technique is developed for the detection of high harmonics generated by relativistic and subrelativistic laser pulses irradiating a solid target. Features in the spectra of harmonics generated by a parametric mid-IR laser system and near-IR laser system based on chirped pulse amplification were analyzed. Experimental spectra of harmonics in the range up to 35 nm were recorded. They can be used as a source of coherent radiation in the extreme UV region. [ABSTRACT FROM AUTHOR]

Background and Objectives: A brief biography of Valery Tuchin, head of Optics and Biophotonics Department of Saratov State University, Doctor of Physical and Mathematical Sciences, Professor, Corresponding Member of the Russian Academy of Sciences is presented; his contribution to laser physics and biophotonics is discussed. Summary: Scientific activity of Valery Tuchin in the 60s was associated with laser physics. His interests included fluctuations in laser radiation, dynamic processes in gas-discharge lasers, and modulation characteristics of lasers. In the mid-80s, Professor Valery Tuchin began to create his own scientific school in the field of tissue optics, which eventually developed into the interdisciplinary science of biomedical photonics, and pioneered “tissue optical clearing” as a new direction. Over the years, the results achieved have received international recognition. Tuchin’s students continue to move along a given vector, developing his ideas and achieving great success and recognition not only in Russia but also abroad. He generously shares ideas with colleagues, connecting Saratov State University with scientific groups around the world. His authority and charisma, as well as his tremendous energy and efficiency, make it possible to implement great international projects, conferences and symposiums. Valery Tuchin is the organizer and inspirer of the Saratov Fall Meeting, which is widely known in the scientific world. Thanks to Valery Tuchin, students and young scientists from Saratov State University were among the first in Russia to have the opportunity to listen to lectures of heads of leading scientific groups, present and discuss their results, establish scientific and friendly connections with peers from other cities of the world. From 1989 to the present, Valery Tuchin has been the permanent head of the Optics and Biophotonics Department at Saratov State University. Conclusion: Professor Valery Tuchin is a unique example of both an outstanding scientist and a talented teacher and organizer of the scientific process. He have created a scientific school known all over the world. His fruitful scientific and educational activities have marked by the awarding of medals, orders, honorary titles and prizes from the State and various scientific communities, as SPIE, OCA, Laser Association of the Russian Federation and others.

Based on Thomson scattering classical theory and single electron model, numerical simulation of Thomson scattering X-ray source is completed with the help of MATLAB software. We discuss the influence of waist radius and initial phase of few-cycle laser pulse on maximum radiation energy, maximum radiation power, radiation angle distribution and spectrum when the collision center is at or away from the focus. It is found that the initial z-axis position of the electron has no effect on the overall change trend. The influence ability of waist radius appears a "watershed" phenomenon at b 0 = 4 λ 0 . When b 0 = 1 ∼ 3 λ 0 , with the increase in the waist radius, the maximum radiation energy and the maximum radiation power increase, and the collimation of laser and the monochromaticity of the spectrum become worse. When b 0 ≥ 4 λ 0 , the change in waist radius has no effect on these parameters. In addition, when the initial phase of few-cycle laser pulse increases in the range of 0–360°, the maximum radiation direction rotates counterclockwise, and the values of the maximum radiation energy and the instantaneous power of the maximum radiation energy and the peak value of the spectrum fluctuate only in a small range. [ABSTRACT FROM AUTHOR]

In this paper, two parameters of the applied magnetic field—magnetic field strength and pulse length—are modified, the spatial properties of electron trajectories and radiation are studied, and conclusions are drawn. Under the premise that the radius of the laser pulse waist b0=4λ0, and that the peak amplitude a0=5 corresponds to the peak laser intensity IL=3.45×1019 W/cm2 of the electrons, obtaining high-energy and highly collimated X-rays can be realized by increasing the pulse length up to 6λ0 and increasing the magnitude of the applied magnetic field, or by continuously increasing the pulse length and applying a smaller magnetic field.

Based on the classical theory of nonlinear Thomson scattering and the single electron model, we performed extensive numerical simulations in MATLAB R2022b to comprehensively investigate how the initial phase of a tightly focused, circularly polarized laser pulse affects the radiation characteristics of high-energy electrons at different energy levels. Our findings indicate that the polar angle corresponding to the maximum radiation energy remains constant as the initial phase of the laser changes from 0 to 2π, while the azimuth angle correspondingly moves from 0 to 2π. Moreover, as the initial phase changes, the pulse width of the electron radiation peak displays a quasi-periodic oscillation with a period of π. Notably, an increase in the initial energy of the electrons results in a significant enhancement in both the peak radiation value and the collimation of the radiation. These results demonstrate that manipulating the initial phase of the driving laser pulse enables effective control over the spatial distribution of radiation light.