Source Of X-ray Radiation Research Articles

Fully relativistic derivation of the thermal Sunyaev-Zel'dovich effect

We present the first fully and inherently relativistic derivation of the thermal Sunyaev-Zel'dovich effect. This work uses the formalism historically applied to compute radiation spectra emerging from inverse Thomson/Compton sources of x-ray radiation. Comparing our results to the traditional approach based on relativistically-corrected classical Kompaneets equation, we find small, but systematic differences. Most notable are the modest (⩽10%) differences in the crossover frequency where the spectral distortion due to the Sunyaev-Zel'dovich effect vanishes, and the quadratic scaling of the energy shift with the electron cloud temperatures.

Study in the Extreme UV Range of the Spectral Transmission of Nickel Plasma Created under the Effect of an X-Ray Pulse of the Z-Pinch

Spectral properties of the high-temperature plasma obtained by exposing a nickel layer to a source of high-power X-ray radiation (a power of 6–10 TW with a duration of 7–10 ns) based on a Z-pinch, formed during implosion of tungsten multi-wire arrays at the Angara-5-1 facility, are studied. In this case, the Z-pinch radiation heats the target and turns it into the hot plasma, and the same radiation probes the target plasma to determine the spectral dependence of the transmission of this plasma. An original scheme is proposed for measuring the incident, transmitted and self-emission of a target simultaneously in one experiment in the frame mode using a grazing incidence diffraction spectrograph. Using laser shadow imaging, experimental data are obtained on the velocity of the plasma expansion on the irradiated and back sides of the target, which reached 100 km/s. Targets made of thin Ni layers deposited on a mylar film are studied. An irradiationinduced multiple increase in the transmission of the target plasma in the EUV range is observed compared to the transmittance of the target in the cold state. The dependence of the absorption spectrum of the plasma and the accompanying self-radiation of the target on the power and shape of the heating pulse is studied. The measurement results are compared with numerical calculations performed using the RALEF-2D two-dimensional radiation code, which has been repeatedly used previously to simulate similar experiments. The shape of the spectral dependence of the transmission in the experiment and calculation is similar in the range of ∼30–200 Å, but the model plasma transmission (∼0.8–0.9) is higher than that obtained using a spectrograph and X-ray multi-frame photography (∼0.5–0.6).

Comparison of methods for changing the spectrum of radiation of a pulse x-ray source to determine the most effective two-energy image processing

For detecting substances with similar chemical composition and density, one of the promising methods of non-destructive testing is dual-energy processing of X-ray images. In particular, dual-energy transformation algorithms can be used to search for minerals hidden within barren rock. This method is most effective when the conditions for registering X-ray images and energy levels are properly selected. This study compares the effectiveness of image processing using the dual-energy method for three cases of spectral composition variation: firstly, as a result of adjusting the voltage on the X-ray tube; secondly, by attenuating low-energy radiation through the use of a copper filter; and thirdly, by combining these two methods. Beryl particles embedded in ground muscovite are used as samples for detection. The study utilizes a pulsed X-ray radiation source that generates radiation pulses of nanosecond duration. An original high-voltage generator scheme has been implemented for the method of regulating radiation energy by changing the peak voltage on the X-ray tube. The use of X-ray sources of this type enables the acquisition of high-resolution X-ray images of moving objects.

X-ray AGM activity classes based on SDSS spectra

Sources of X-ray radiation are very interesting and at the same time little studied. Their class mainly includes objects that exhibit a certain activity, such as AGNs, cataclysmic variable stars, white dwarfs, pulsars, etc. Identification of X-ray sources is a rather difficult task, and it is not always possible to detect an optical object. In this work, we tried to carry out a spectral classification of X-ray AGNs and identify activity classes, taking as a basis the ROSAT BSC/FSC catalog of X-ray AGNs, compiled on the basis of low-dispersion spectral plates of the first Byurakan survey. We identified these objects with the SDSS spectral catalog and tried, by carefully studying the spectra, to find out their activity classes, as well as to understand which activity class is more common in these sources.

Compact hard x-ray flash radiography device based on wire-shorted low-impedance rod pinch diode.

A rod pinch diode (RPD) is a feasible load configuration to generate a high-brightness, small-size hard x-ray radiation source. In this paper, the radiography performance of a wire-shorted low-impedance RPD on a compactly designed table-top driver (WRPD-1) is demonstrated for the first time. The driver consists of four high-power discharge branches connected in parallel, with each branch consisting of two metal-film capacitors and one multigap field-distortion switch in series. The four branches are triggered synchronously to generate a fast-rising current pulse: the inductance of the load section at the short circuit is ∼10 nH, and the short-circuit current amplitude is ∼325kA at ±90kV charging voltage, with a 10%-90% rise time of 110ns. With a low-impedance RPD shorted by an 18-µm-diameter aluminum wire, a quasi-spherical x-ray focal spot with diameter <0.6mm (width of the half-maximum grayscale) and a pulse duration of ∼25ns (half-width of the radiation pulse) is obtained at ±70kV charging voltage, and the imaging resolution excels 10 lp/mm under 1.56× magnification. According to the transmission-absorption x-ray spectrum estimation, the average emitted photon energy is ∼30keV with a distinct peak in the 10-15keV range that corresponds to the L-lines of tungsten, and the total energy of photons >10keV reaches ∼1.16J. The present results show that the device can serve well for the flash radiography diagnosis and potentially as an efficient light source for dynamic x-ray diffraction.

Feasibility study of high-power electron linac for clinical X-ray ROAD-FLASH therapy system

Introduction: This study examines how a practical source of X-ray radiation, capable of delivering unprecedented X-ray of 100 Gy/s at 1 m for X-ray FLASH radiotherapy can be designed.Methods: We proposed the design of a linac, capable of accelerating 18 MeV 8 mA electron beam with further conversion to bremsstrahlung X-rays. The design is based on L-band traveling wave accelerating structures with high power efficiency, operating in a short-burst/long-pulse regime that allows operating power supply in a regime, beyond its specifications.Results: This study demonstrates the feasibility of a high-power linac for a clinical X-ray FLASH therapy system, using detailed analysis and simulations. Despite ∼500x higher output than a standard clinical linac, the design utilizes available accelerator components for maximal practicality.Discussion: Recent studies have demonstrated that the FLASH effect that allows to effectively kill tumor cells while sparing normal tissue occurs when large dose rates (≥40 Gy/s) are delivered in less than 1 s. Photons are very attractive since modest energies of several MeV are needed, which can be achieved with compact and cost-efficient accelerators. However, since the efficiency of electron-to-photon conversion is only a few percent, the required beam intensity must be an order of magnitude higher than that state-of-the-art accelerators can provide. The proposed ROAD-FLASH accelerator layout allows achieving both the FLASH dose rate and superior dose conformity, comparing to the similar projects. The current paper focuses on providing a technical roadmap for building an economical and practical linear accelerator for ROAD X-ray FLASH delivery.

Powerful Source of Soft X-Ray Radiation Based on Z-Pinch of Nested Arrays for Experiments in High-Energy Density Physics

Powerful Source of Soft X-Ray Radiation Based on Z-Pinch of Nested Arrays for Experiments in High-Energy Density Physics

The laser-electron source of X-ray radiation (from the opening statement at workshop dedicated to the 85th anniversary of B.S. Ishkhanov in SINP MSU on October 26, 2023)

The work, as well as the seminar at which it was reported, is devoted to the memory of the outstanding physicist-nuclear scientist, professor of Moscow State University B.S. Ishkhanov, namely his contribution to the research and development of LEXG — laser-electronic X-ray generators. Relevance and prospects of this direction are connected with «gap» between two existing types of X-ray sources: on the one hand — X-ray tubes, and on the other - electronic accelerators, storage rings and free electrons lasers. It’s about a huge difference in their bundle characteristics, cost, scale, energy consumption, etc. The history of modern projects abroad, as well as the LEXG project of MSU–Jilin University, led by Prof. B.S. Ishkhanov, are briefly presented. From the point of view of their applications, the LEXG designs can be divided into two types with different scale of the devices. The first is the replacement of serial X-ray tubes and the second is radiation medicine, nuclear technology and nuclear physics research. International conferences on LEXG have been held since 2008. The list of these is given in the Annex to the article.

Laser–Electron Source of X-Ray Radiation (Based on the Introductory Speech at the Seminar Dedicated to the 85th Anniversary of B.S. Ishkhanov in SINP MSU, October 26, 2023)

Laser–Electron Source of X-Ray Radiation (Based on the Introductory Speech at the Seminar Dedicated to the 85th Anniversary of B.S. Ishkhanov in SINP MSU, October 26, 2023)

Robust Isolated Attosecond Pulse Generation with Self-Compressed Subcycle Drivers from Hollow Capillary Fibers.

High-order harmonic generation (HHG) arising from the nonperturbative interaction of intense light fields with matter constitutes a well-established tabletop source of coherent extreme-ultraviolet and soft X-ray radiation, which is typically emitted as attosecond pulse trains. However, ultrafast applications increasingly demand isolated attosecond pulses (IAPs), which offer great promise for advancing precision control of electron dynamics. Yet, the direct generation of IAPs typically requires the synthesis of near-single-cycle intense driving fields, which is technologically challenging. In this work, we theoretically demonstrate a novel scheme for the straightforward and compact generation of IAPs from multicycle infrared drivers using hollow capillary fibers (HCFs). Starting from a standard, intense multicycle infrared pulse, a light transient is generated by extreme soliton self-compression in a HCF with decreasing pressure and is subsequently used to drive HHG in a gas target. Owing to the subcycle confinement of the HHG process, high-contrast IAPs are continuously emitted almost independently of the carrier-envelope phase (CEP) of the optimally self-compressed drivers. This results in a CEP-robust scheme which is also stable under macroscopic propagation of the high harmonics in a gas target. Our results open the way to a new generation of integrated all-fiber IAP sources, overcoming the efficiency limitations of usual gating techniques for multicycle drivers.

Nested design and numerical simulation of ellipsoidal glass tube X-ray lens

This paper presents a nested optimization design scheme for ellipsoidal glass tubes. The lens, also known as a mirror, is composed of multiple ellipsoidal glass tubes with varying semi-major and semi-minor axes, nested within a larger-diameter ellipsoidal glass tube. Compared to Traditional Ellipsoidal Single-bounce Lens (TESL), the Nested Ellipsoidal Glass Tube X-ray Lens (NEXL) can utilize a smaller or even no beam stop at its input, mitigating the impact of the direct X-ray beam on the NEXL's focused beam and thereby enhancing X-ray source utilization. NEXLs can be designed with a large input focal distance, making them suitable for synchrotron radiation X-ray sources located significant distances from the source point to the sample. Simulation results show that for a synchrotron X-ray source 34,000 mm from the sample, a NEXL with six ellipsoidal sub-tubes offers a solid acceptance angle four times greater than a single ellipsoidal glass tube lens. Furthermore, for standard laboratory X-ray sources, a NEXL with three sub-tubes provides double the solid acceptance angle compared to a single-tube lens. These features position NEXLs as highly versatile in the field of X-ray technology.

Spatial and temporal evolution of laser plasma produced using a double-stream gas puff target

Laser plasma produced using a double-stream gas puff target is an intense source of soft x-ray (SXR) and extreme ultraviolet (EUV) radiation, however, without the harmful emission of debris associated with a solid target. Debris-free laser plasma x-ray and EUV sources have been applied in many various applications, including metrology, imaging in a nanoscale, tomography, processing materials, emission and absorption spectroscopy, laboratory astrophysics and astrochemistry, radiobiology, and radiochemistry. In this work, the results of the experimental and theoretical studies on the spatial and temporal evolution of laser plasma produced as a result of irradiation of an argon/helium gas puff target with laser pulses of 1.3 or 6 ns time duration generated with an Nd:YAG laser system are presented. Imaging and spectral measurements of SXR emission from the plasma, created in the double-stream gas puff target, have been performed with the use of an x-ray streak camera. The analysis of the results of spectral measurements, supported by numerical simulations of plasma x-ray emission, allowed the estimation of the plasma electron temperature and its changes over time. Experimental data were compared with the results of theoretical studies performed using a computer model of plasma hydrodynamics. It was shown that plasma expansion is fast enough to reduce the plasma density in the laser focus area during the laser–plasma interaction.

First white beam on a von Hámos spectrometer at the PolyX beamline of SOLARIS

Synchrotrons are brilliant sources of X-ray radiation used in a variety of methods to study the structure of matter and dynamics of processes on the atomic scale. X-ray spectroscopy methods at synchrotrons are typically combined with the beam monochromatization which guarantees better energy resolution but also reduces orders of magnitude the photon flux incident on the sample and thus wastes the vast majority of the photons produced. Here we report on the commissioning of an X-ray spectrometer at the PolyX beamline of SOLARIS specialized in application of white, broadband and monochromatic X-ray beam in multimodal microimaging, microtomography and microscpectroscopic studies. The spectrometer was used to acquire good quality Fe K-edge X-ray absorption spectrum over about 120 eV-range within seconds. In this work we present the first X-ray absorption spectrum measured using a synchrotron white beam in combination with a von Hámos geometry-based spectrometer.

Preparation and testing of laterally graded multilayer with a double genetic algorithm and root mean square error optimization in differential deposition.

Lateral graded multilayer can realize reflection, collimation and focusing of hard X-ray, and are currently the research frontier and hotspot of synchrotron radiation and high-performance X-ray sources. To reduce the d-spacing error of graded multilayers, a root mean square error optimization method based on double genetic algorithm (DGA-RMSE) is proposed. The theoretical d-spacing distribution is obtained by optical design, and the range is 1.9 ∼ 3.1 nm. The optimized d-spacing distribution is obtained by convolution of particle beam function and continuous monotonic rate distribution line (RDL) which is constructed in the form of a polynomial. The GA is applied to optimize variables from the polynomial twice, and the RMSE of thickness error is optimized and converged to 0.0065 nm. The final thickness error which is measured by the grazing incidence X-ray reflectivity (GIXRR) is consistent with the theoretical calculation. The results show that DGA-RMSE can precisely select polynomial function of RDL, reducing the error in high-precision magnetron sputtering and mask technology.

Simulation of Subpicosecond Laser-Plasma X-ray Radiation Source

Simulation of Subpicosecond Laser-Plasma X-ray Radiation Source

Experimental Analysis of Radiation Protection Offered by a Novel Exoskeleton-Based Radiation Protection System versus Conventional Lead Aprons

PurposeTo evaluate the radiation protection offered by an exoskeleton-based radiation protection system (Stemrad MD) and to compare it with that offered by conventional lead aprons. MethodsThe experimental setup involved 2 anthropomorphic phantoms, an operator, a patient, and a C-arm as the x-ray radiation source. Thermoluminescent detectors were used to measure radiation doses to different radiosensitive body parts on the operator phantom both with the exoskeleton and a conventional lead apron at the left radial and right femoral positions. Detected radiation doses for the exoskeleton and lead apron for different body parts and positions were compared. ResultsAt the left radial position, the mean radiation dose (mGy) reduction by the exoskeleton compared with that by the lead apron was >90% for the left eye lens (0.22 ± 0.13 vs 5.18 ± 0.08; P < .0001), right eye lens (0.23 ± 0.13 vs 4.98 ± 0.10; P < .0001), left head (0.11 ± 0.16 vs 3.53 ± 0.07; P < .0001), right head (0.27 ± 0.09 vs 3.12 ± 0.10; P < .0001), and left brain (0.04 ± 0.08 vs 0.46 ± 0.07; P < .0001). At the right femoral position, radiation reduction was >90% for the left eye lens (0.14 ± 0.10 vs 4.16 ± 0.09; P < .0001), right eye lens (0.06 ± 0.08 vs 1.90 ± 0.11; P < .0001), left head (0.10 ± 0.08 vs 4.39 ± 0.08; P < .0001), left brain (0.03 ± 0.07 vs 1.44 ± 0.08; P < .0001), right brain (0.00 ± 0.14 vs 0.11 ± 0.13; P = .06), and thyroid (0.04 ± 0.07 vs 0.27 ± 0.09; P < .0001). Protection of the torso was equivalent to that offered by conventional lead aprons. ConclusionsThe exoskeleton-based system provided superior radiation protection to the physician compared with that provided by conventional lead aprons. The effects are particularly impactful for the brain, eye lens, and head areas.

In situ high-pressure wide-angle hard x-ray photon correlation spectroscopy: A versatile tool probing atomic dynamics of extreme condition matter

With the advent of new synchrotron radiation x-ray sources that provide a significantly enhanced coherent flux, high-energy x-ray photon correlation spectroscopy measurements can be performed on materials in a diamond anvil cell. Essential information on atomic dynamics that was previously inaccessible can be obtained for various novel phenomena emerging under extreme conditions. This article discusses the importance, feasibility, and experimental details of this technique, as well as the opportunities that it offers to address critical scientific challenges.

Assessment of the impact of noise level on the accuracy of reconstruction of the image of the industrial product

The traditional tomography is an effective remedy for medical diagnostics, nondestructive control of industrial designs and for quality check of industrial products. Tomographic visualization of objects in case of an incomplete viewing angle, limited number of projections and/or the insufficient power of a source of x-ray radiation is strongly incorrect return task. Article is devoted to case research when noise in input data significantly affect convergence and quality of the reconstructed image.

Pulsating mode in X-ray generators based on the SBN-61 crystal

Currently, pyroelectric crystals are used in the development of new portable sources of X-ray and neutron radiation. Typically, X-rays are produced when pyroelectric crystals are heated or cooled. In this work, in an X-ray generator based on a ferroelectric crystal of barium-strontium niobate Sr0.61Ba0.39Nb2O6, the pulsations of the electron and X-ray flux were registered at a constant temperature when the gas pressure increased in the range 2·10−2–10−1 Torr. The electron flux had the shape of a cross in the crystal plane. The flash duration did not exceed 0.04 seconds. The observed effect is explained by the movement of domain boundaries on the depolarized crystal face in vacuum, resulting in a large surface charge and, accordingly, an electric potential, leading to the formation of a pulsed electron flux.

Generation of Highly Charged Au Ion in Laser-Produced Plasma for Water Window X-ray Radiation Sources

Highly charged ions in the plasma produced by high-power laser can radiate bright and short-pulse X-rays. Owing to the unresolved transition array (UTA) from the high-Z elements, laser produced plasma has been applied for developing X-ray sources. In particular, X-rays in the water-window (WW) region (2.3–4.4 nm) is utilized as the light source of the X-ray microscopy to observe living organisms under high contrast and resolution. In this work, WW X-rays radiated from a laser (1064 nm, 6.2 ns) produced Au-plasma has been studied. UTA spectrum in the WW range has been observed through a grazing incident spectrometer (GIS). Dependence of Au-ion charge state distribution on laser intensity has been experimentally investigated and evaluated by a transition probability data calculated by the flexible atomic code. The integrated soft X-ray emission has been observed through a pinhole camera with a 1.0-μm Ti-filter, combined with a 2-D plasma radiation scanning achieved by the GIS. An intense WW emission region 200-μm away from the target surface has been observed, which indicates a more effective area is possible to be utilized for a practical use.