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A significant change in the dispersion relation of low frequency electromagnetic Alfven modes occurs when ion beam interacts with a magnetized plasma, depending on plasma and the beam parameters. The growth rates and dispersion relation of pure and shear Alfven modes have been estimated. Pure Alfven wave suffers a cyclotron damping when it interacts with the charged particles of beam via linear cyclotron interaction. Only when the beam ions travel in the opposite direction from the shear Alfven wave via fast cyclotron interaction can destabilize the left-hand polarized shear Alfven mode. The Alfven wave dispersion characteristics change due to collisions between plasma components and result in damping of the waves by acting as a stabilizing influence. The growth rate and the frequency of generated Alfven waves get affected differently for right-hand and left-hand polarized Alfven modes due to the collisions between beam ions and plasma components. The growth rate has smaller values in the presence of collisions which show a collisional damping of pure and shear modes in the beam plasma system. [ABSTRACT FROM AUTHOR]

SUMMARY: DNA rearrangements, including inversions, translocations, and large insertions/deletions (indels), are crucial for crop evolution, domestication, and improvement. The rearrangements are frequently induced by ion beams via the mis‐repair of DNA double‐strand breaks (DSBs). Unfortunately, how ion beam‐induced DSBs are repaired has not been comprehensively analyzed and the mechanisms underlying DNA rearrangements remain unclear. In this study, clonal sectors originating from single mutated cells in carbon ion‐irradiated plants were used for whole‐genome sequencing analyses after Arabidopsis seeds and seedlings were irradiated. Comparative analyses of the induced mutations (e.g., size and frequency of indels and microhomology at the junctions of the rearrangements) in the irradiated materials suggested that the broken/rejoined DSB ends were more extensively processed in seedlings than in seeds. A mutation to canonical non‐homologous end‐joining (c‐NHEJ), which is a DSB repair pathway with minimal processing of DSB ends, increased the sensitivity to ion beams more in the seeds than in the seedlings, which was consistent with the junction analysis results, indicative of the minor contribution of c‐NHEJ to the carbon ion‐induced DSB repair in seedlings. Considering the characteristics of the large templated insertions in irradiated seedlings, ion‐beam‐induced DSBs in seedlings are likely repaired primarily by a polymerase theta‐mediated pathway. Polymerase theta‐deficient seedlings were more sensitive to ion beams than the c‐NHEJ‐deficient seedlings, consistent with this hypothesis. This study revealed the key characteristics of ion beam‐induced DSBs and the associated repair mechanisms related to the physiological status of the irradiated materials, with implications for elucidating the occurrence and induction of rearrangements. Significance Statement: DNA rearrangements, which are critical for crop improvement, can be randomly induced in genomes by ion beams. Our genomic analysis of irradiated plants revealed significant differences in the characteristics of the DNA rearrangements in seeds and seedlings, providing important insights into double‐strand break repair mechanisms and the associated rearrangement formation related to the physiological status of the irradiated materials. [ABSTRACT FROM AUTHOR]

Space debris poses a great threat to space stations. When a collision hazard is detected, the space station's orbit should be adjusted. An alternative approach is to apply collision avoidance measures that consist in creating an external impact on the space debris object to change its orbit and increase the miss distance slightly. Such an impact can be carried out using a ground-based or orbital laser, through the use of nano-tugs thrusters, or by placing a cloud of particles in the path of the object. This study proposes to use the plume of a thruster of an active spacecraft called an Ion Beam Interceptor. When a potential collision is detected, the interceptor undocks from the space station, approaches the space debris object and directs an ion beam, which is generated by the spacecraft's thrusters, at it. Hitting into the surface of the object, the particles of the ion beam exert a force effect on it, which leads to the required change in the orbit. After the completion of the maneuver, the interceptor returns to the space station for refueling and servicing. The objective of the study is a preliminary assessment of the feasibility and effectiveness of the proposed approach of protecting a space station from space debris impact using an active spacecraft. A mission profile of the space station protection is proposed. A series of numerical simulations are performed to determine mission parameters and fuel costs. Based on an analysis of the orbits of space objects located near the space station, the maximum angle between the orbital planes of the dangerous object and the station are determined at which it is advisable to use the Ion Beam Interceptor. The developed concept also allows to implement just-in-time collision avoidance measures for space debris objects whose orbital planes are close to the plane of the space station. • The concept of the Ion Beam Interceptor spacecraft designed to protect the space station from a predicted collision is developed. • A series of calculations were carried out to analyze the possibility of protecting the international space station from potentially dangerous objects. • The developed mission can be effectively used to protect the International Space Station from objects whose orbit is deviated from the station's orbit by no more than 0.23 rad. • The concept makes it possible to implement just-in-time collision avoidance measures for space debris objects in the above range of orbits in LEO. [ABSTRACT FROM AUTHOR]

WO3 is considered to be significant for diverse applications such as gas sensing, photocatalysts, and photovoltaic devices because of its optical wide band gap. Ion beam treatment of various metal oxides produces defects that modify various properties such as topographical, structural, and optical characteristics of the metal oxides. When the energetic ion pass through the target materials, it causes two kinds of energy losses, i.e., nuclear and electronic energy loss. In low-energy ion beam treatment of thin films, nuclear energy loss dominates over electronic energy loss. In our current study, thin films of tungsten oxide were grown on substrates of glass and silicon by the RF-sputtering method. The sputtered WO3 thin films were exposed to an ion beam of Au iosn with an energy of 80 keV at various fluences of 5E14 ions/cm2, 1E15 ions/cm2, and 5E15 ions/cm2. Atomic force microscopy (AFM) shows that, after implantation, enhancement in grain size was observed from 49.5 nm to 56.6 nm. The optical study displays the alteration in the energy band gap of ion-implanted WO3 thin films from 2.75 eV to 2.99 eV. From Raman spectroscopy, the phase observed is monoclinic for virgin and implanted samples. PL spectroscopy of virgin and ion beam-implanted WO3 thin films shows emission spectra at the wavelength of 580 nm at an excitation wavelength of 420 nm. X-ray photoelectron spectroscopy shows the appearance of tungsten and oxygen atoms and shows the electronic structure variation after Au ion beam implantation. [ABSTRACT FROM AUTHOR]

In modern medicine, accelerator technology, semiconductor production, there is a need to develop ion sources of various elements capable of generating currents in a wide range of values from 1 μA to 100 mA. Before using the created ion sources in specific applied cases, it is necessary to study them in detail, optimize the operating parameters and study the main characteristics of the ion beam. Current, emittance, brightness, energy distribution and mass composition, stability of the beam output signal are important for obtaining a quality result. The article presents a stand for testing ion sources developed at the IAP of NASU. The developed installation allows researching various sources of metal and gas ions, both negative and positive ions. The installation has all the tools for a detailed study of such parameters of the ion current as the distribution of ions by energy, by mass, emittance, beam profile, working gas consumption. The developed device for measuring the distribution of ions by mass allows studying the elemental composition of the beam. Measurement of the distribution of particles by energy is necessary to study the source for the possibility of its use with specific accelerators of charged particles and implantation technologies. The emittance meter allows you to study the emittance of the beam and obtain its profile. At the installation, a series of studies of the sputtering source of metal ions, the duoplasmatron, and the source of negative ions were carried out, the characteristics of the ion beams created by them were studied in detail, and the values of emittance and mass distribution of particles were determined. The developed facility allows for detailed research of almost any type of ion sources for ion implantation technologies. [ABSTRACT FROM AUTHOR]

Biofertilizers are promising technologies for achieving sustainable agriculture. However, high-temperature tolerance is a constraint that limits the function of microbial inoculants. To characterize the genetic changes responsible for the high-temperature tolerance of rhizobia, mutant screening was performed using Bradyrhizobium diazoefficiens USDA110. The wild-type cells were mutagenized with carbon-ion irradiation, and two mutant strains, designated M10 and M14, were obtained after a three-day heat-shock treatment at 43 °C. In particular, M14 showed superior growth at 36 °C, at which temperature growth of the wild type was extremely slow, whereas M14 grew more slowly than the wild type at 32 °C. Whole-genome sequencing revealed that M10 had seven point mutations, whereas M14 had eight point mutations together with a 1.27 Mb inversion. RNA sequencing showed that the number of differentially expressed genes greatly exceeded the actual number of induced mutations. In M14, a gene cluster associated with pyruvate metabolism was markedly downregulated, probably because of disjunction with the promoter region after inversion, and was considered to be the cause of the slow growth rate of M14 at 32 °C. Notably, transmembrane proteins, including porins, were enriched among the genes upregulated in both M10 and M14. M14 was confirmed to retain symbiotic functions with soybeans. These results indicate that high-temperature tolerance was conferred by random mutagenesis while the symbiotic functions of rhizobia was maintained. [ABSTRACT FROM AUTHOR]

The PVC-PVDF-GO nanocomposites thin films were prepared by solution casting method. A thin film of Polyvinyl chloride (PVC), Polyvinylidene fluoride (PVDF), PVC-PVDF-GO was uniformly irradiated with a carbon ion beam at 70 MeV over a surface of 1 cm2 in a vacuum of almost 5 × 10−7 torr with ion fluencies of 1 × 1012 and 2 × 1013 ions/cm2. Fourier transform infrared (FTIR) spectroscopy was observed to track changes in the β-content, represented as F(β)%, during the recrystallization of PVDF after irradiation. At ambient temperature, the variation of dielectric constant and dielectric loss has been studied for pristine and irradiated samples. Ion beam irradiation caused significant changes to the dielectric constant and dielectric loss. After irradiation, the dielectric constant (ϵ′) increases at lower fluence (1 × 1012 ions/cm2), but decreases at higher fluence (2 × 1013 ions/cm2) in comparison with the pristine polymer samples. In PVDF, free radicals are generated by chain scission and cross-linking. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the use of EBT3 film, specifically the active layer, for monitoring low-energy ion beams. The film's wettability was enhanced, and its surface free energy increased by 200% after irradiation, as determined by the contact angle technique. SEM analysis showed that the surface of the film became rougher, with a needle-like structure, and increased from 80 nm for the pristine sample to 116 nm for the sample exposed to the highest fluence. XRD analysis revealed an increase in crystallite dimension and a decrease in crystallinity. ATR-FTIR analysis demonstrated that the modified film is sensitive to low-energy ion beams, with certain bands showing significant changes that can be controlled by adjusting the ion fluence. These changes affect the color properties of the EBT3 film, which can be used to monitor the ion beam. The visible spectrum exhibited two distinct colors: blue at 648 nm and red at 596 nm. The blue-to-red ratio was calibrated based on the applied fluence using a polynomial function. The film's net optical density was separately analyzed for each color, with the blue color being dominant. However, the red color accurately calibrated the film's response to low-energy ion beams with a usable fluence of up to 1 × 1017 ion/cm2. In conclusion, low-energy ion beams caused significant structural and optical changes in the active layer of EBT3 films, which can be controlled and customized for monitoring ion beams. [ABSTRACT FROM AUTHOR]

In the present study, we apply and further develop an interdisciplinary approach to investigate textile remnants of a 17th-century shirt discovered during archaeological excavations by the Institute of Archaeology, Russian Academy of Sciences (conducted in February 2021 under the direction of N.I. Savel'ev) in the former Goncharnaya Sloboda (Pottery Settlement area) of Moscow. When examining a fragment of the shirt with preserved decorative elements, we use a set of complementary analytical methods. The conducted research reveals that the shirt was sewn from linen fabric and bordered with woven silk ribbons. The spun golden threads used for embroidering decorative elements on the shirt are produced by twisting a core thread made of silver (with copper and gold additives) ribbon approximately 340 μm wide and 14 μm thick, with a layer of gold 1–1.5 μm thick applied to its surface. A silk thread is used as the core. A reconstruction of the method for manufacturing the metallic braided ribbon is carried out. High-resolution optical images of the spun gold threads are obtained, revealing their structure. [ABSTRACT FROM AUTHOR]

Desired modifications of surfaces at the nanoscale may be achieved using energetic ion beams. In the present work, a complete study of self-assembled ripple pattern fabrication on Si and Ge by 100 keV Ar+ ion beam bombardment is discussed. The irradiation was performed in the ion fluence range of ≈3 × 1017 to 9 × 1017 ions/cm2 and at an incident angle of θ ≈ 60° with respect to the surface normal. The investigation focuses on topographical studies of pattern formation using atomic force microscopy, and induced damage profiles inside Si and Ge by Rutherford backscattering spectrometry and transmission electron microscopy. The ripple wavelength was found to scale with ion fluence, and energetic ions created more defects inside Si as compared to that of Ge. Although earlier reports suggested that Ge is resistant to structural changes upon Ar+ ion irradiation, in the present case, a ripple pattern is observed on both Si and Ge. The irradiated Si and Ge targets clearly show visible damage peaks between channel numbers (1000–1100) for Si and (1500–1600) for Ge. The clustering of defects leads to a subsequent increase of the damage peak in irradiated samples (for an ion fluence of ≈9 × 1017 ions/cm2) compared to that in unirradiated samples.

The formation of longitudinal, nonlinear structures in an interacting ion beam, spin‐1/2 quantum, electron‐ion plasma is reported by employing a separate spin evolution quantum hydrodynamic model (SSE‐QHD). The reductive perturbation method is followed to develop the KdV equations. In the presence of an ion beam and keeping the finite electron inertial effects, ion acoustic (IA) soliton and spin electron acoustic (SEA) soliton are found. The critical values of beam speed and spin polarization, required for the existence of solitary structures, are highlighted. It is prescribed that the present model supports rarefactive and compressive SEA soliton and compressive IA soliton. It is shown that the ion beam is essential for the existence of a compressive SEA solitary structure. We have also calculated and compared the energy densities of both solitons. Furthermore, the dependence of the nonlinear structures on the beam parameters and spin polarization are also examined. Our findings would be useful to understand the new spin‐dependent nonlinear structures as well as the features of nonlinear IA waves in ion beam–plasma interactions. [ABSTRACT FROM AUTHOR]

Small m N -class gridded ion thrusters are usually tested in a vacuum chamber without the use of a neutralizer, relying on self-neutralization of the ion beam due to interaction with facility walls. Langmuir probe measurements performed immediately downstream of such a thruster reveal values of the plasma potential of several hundreds of volts. If this locally very high potential indeed exists, it would have significant impact on the erosion rate of RIT grids and thus reduce the lifetime of thrusters compared to the generally accepted plasma potential of a few tens of volts. Further measurements performed with a movable Langmuir and emissive probes indicate that the probe mount violates the ability of the ion beam to self-neutralize. This is concluded due to dependence of the measured potential value on the degree of neutralization introduced in the experiment. Particle-in-cell and direct-simulation Monte Carlo simulations of the ion beam corresponding to experimental conditions (ion energy E Xe + = 1.5   keV and ion beam current I Xe + = 17   mA ) are carried out to determine the phenomena responsible for the self-neutralization; mainly, reactions with neutral species such as ionization by electron or ion impact and secondary electron emission (SEE) from the facility walls are compared. Reasonable agreement with measurements is achieved, and SEE is determined to be the primary source of electrons, indicating that facility and measurement disturbance effects majorly influence testing of (non-neutralized) ion beams. Further, limitations of the applicability of probe diagnostics on non-neutralized ion beams are described. [ABSTRACT FROM AUTHOR]

The results of the ion source of the neutron generator upgrade, which makes it possible to operate in a CW mode, are presented. A magnetic trap consisting of permanent magnets (NdFeB) was developed. A 3-electrode extraction system equipped with a magnetic lens was used to extract the deuterium ion beam. Calculations are made for the formation of a deuterium ion beam with a current over 500 mA and an energy of 100 keV with practically no losses in the extraction system. [ABSTRACT FROM AUTHOR]

Research and development in the field of space debris (SD) removal technologies is one of the most important and urgent tasks facing all spacefaring nations. By now, a large number of different concepts of removal have already been proposed. One of them is the SD removal by ion beam generated by an ion source installed on board a service spacecraft (SSC). A detailed understanding of the process of ion beam interaction with the SD surface is required to develop an optimal control algorithm for the virtual SSC-SD mated configuration in order to improve this method of SD removal. In addition, when designing the SSC, it is necessary to take into account back flows of the material sputtered from the surface of removed SD by the ion beam, which can contaminate the SSC operating surfaces during the removal maneuver. Within the framework of the presented work, experimental studies were performed to determine the coefficient of accommodation of the ion impulse during the ion beam interaction with the surface of the target simulating the external surface of the removed object. Besides, the flow density of the sputtered target material was experimentally evaluated during its exposure to the ion beam. To do this, we used the radio-frequency ion source (injector) with a beam diameter of 160 mm, which is supposed to be used as an actuating unit on board the SSC designed for transporting the SD objects to the disposal orbit or to the orbits with limited life. When measuring the ion beam accommodation coefficient, the presence of additional force arising on the target due to the flow of sputtered material leaving its surface, and the ion-electron emission process on the target, which could distort the experimental data, were taken into account. To estimate the magnitude of the flows of sputtered target material under the influence of the ion beam, a special experimental design was developed for simulating the presence of a point source of sputtered material. The results obtained in this work will be used for modeling the impact of the ion beam on the surface of real SD objects with complex geometry using the finite element method, for refining the control algorithm of the virtual SSC-SDO mated configuration and for developing proposals on the SSC layout, which should reduce or completely eliminate the negative impact associated with the material sputtering from the SDO surface onto the SSC elements. Successful implementation of the developed method of SDO removal will contribute to improving the safety of space activities for all countries and to the development of the rocket-and-space industry in the Russian Federation, in particular. • The accommodation coefficient of the ion beam momentum was determined. • The back flow of sputtered target particles was estimated. • In a first approximation, the form of the target material sputtering indicatrix was obtained. [ABSTRACT FROM AUTHOR]

Biofertilizers are promising technologies for achieving sustainable agriculture. However, high-temperature tolerance is a constraint that limits the function of microbial inoculants. To characterize the genetic changes responsible for the high-temperature tolerance of rhizobia, mutant screening was performed using Bradyrhizobium diazoefficiens USDA110. The wild-type cells were mutagenized with carbon-ion irradiation, and two mutant strains, designated M10 and M14, were obtained after a three-day heat-shock treatment at 43 °C. In particular, M14 showed superior growth at 36 °C, at which temperature growth of the wild type was extremely slow, whereas M14 grew more slowly than the wild type at 32 °C. Whole-genome sequencing revealed that M10 had seven point mutations, whereas M14 had eight point mutations together with a 1.27 Mb inversion. RNA sequencing showed that the number of differentially expressed genes greatly exceeded the actual number of induced mutations. In M14, a gene cluster associated with pyruvate metabolism was markedly downregulated, probably because of disjunction with the promoter region after inversion, and was considered to be the cause of the slow growth rate of M14 at 32 °C. Notably, transmembrane proteins, including porins, were enriched among the genes upregulated in both M10 and M14. M14 was confirmed to retain symbiotic functions with soybeans. These results indicate that high-temperature tolerance was conferred by random mutagenesis while the symbiotic functions of rhizobia was maintained.

The energy deposited in resist during its exposure by ion beam was simulated for ions from a set of rare gases and for gallium. It was shown that the distribution of energy density can be approximated by the product of two Gaussian functions. One of them describes the lateral distribution of energy, the second the dependence on depth. The widths and centres of these Gaussian functions are determined by the energy length (also mentioned in the literature as "Range" or "mean length of trajectories"), the mass of ions and the average atomic number of resist. The obtained description would make it possible to estimate the size of the resist modified volume for any type of ion with energy of tens kiloelectronvolts. So it can be used for a priori estimates of resolution and performance, as well as for the choice of beam energy and ion type based on this. [ABSTRACT FROM AUTHOR]

Selection and classification of suitable materials for exotic applications, including aviation/space, nuclear, oil &gas industries, are still challenging since these applications are typically very demanding in terms of microstructural, mechanical, and electrochemical properties. Surface engineering plays an important role in controlling the properties of the exposed surface, which play key roles in interfacing with another material or exposure to the environment, promoting desirable chemical reactions, and suppression of corrosion. Hence, modification of the surface characteristics of desired materials to the desired depth without altering their bulk properties is essential. The present review focuses on using some of the latest and most advanced surface engineering tool sets such as laser, electron beam (EB), friction stir processing (FSP), ion beam, and plasma immersion ion implantation (PIII). Such techniques provide substantial improvements in wear and corrosion resistance, reduction in frictional losses, increased fatigue life, and enhanced chemical stability at high temperatures for exotic applications. [ABSTRACT FROM AUTHOR]

Polyvinylidene fluoride (PVDF), with β polymorph, is a versatile ferroelectric polymer in device fabrication. Its flexibility, lightweight, and ease of fabrication make it an alternative for electromagnetic interference shielding effectiveness (EMI-SE) improved through swift heavy ion (SHI) irradiation. For the first time, we modified PVDF thin films for EMI-SE applications, exposing them to a 100 MeV oxygen ion beam at varying fluencies. Our analysis encompassed investigating structural study, bonding interactions, surface morphology, and elemental analysis using X-ray diffraction (XRD), Fourier transform infrared spectrophotometry (FTIR), and Field Effect Scanning Electron Microscopy (FESEM) with Energy Dispersive X-ray Spectroscopy (EDS) respectively. Further, we measured dielectric response, cole-cole plot and EMI-SE in Ku-band (12–18 GHz) region using a vector network analyzer (VNA). The results revealed distinctive variations due to the deposition of 100 MeV oxygen ion beams, emphasizing the significant potential of irradiated PVDF thin films for EMI-SE applications. This study contributes to understanding the transformative impact of ion beam exposure on PVDF thin films and highlights their practical promise in emerging technological applications, particularly in EMI-SE. [ABSTRACT FROM AUTHOR]

OPAs (On-chip optical phased arrays) are enabling method for a variety of applications, including metrology, LIDAR (light detection and ranging), and optical interconnects. OPAs must achieve a low beam width, wide-angle steering, effective sidelobe suppression, and other performance requirements. Presence of grating sidelobes from these array configurations in far-field pattern makes it difficult to guide a beam without aliasing when antenna element spacing is more than half a wavelength. Either 1D linear or 2D rectangular arrays make up majority of OPA configurations. This research proposes novel technique for analyzing the laser scanning by ion beam with photogrammetry mapping analysis and nanofabrication. The nanofabrication is carried out using carbon coated optical silicon insulator. The bandwidth restrictions of their antennas as well as photoconductor parasitic have limited the operation bandwidth of previously exhibited plasmonic photoconductive antennas. Here, we demonstrate a potent method for fabricating large-area plasmonic photoconductive nano-antenna arrays that can be used to create broadband terahertz detectors. Signal-to-noise ratio, beam steering step response, beam divergence, power consumption, and scalability are all included in the simulation analysis. [ABSTRACT FROM AUTHOR]

This research deals with electromagnetic compatibility (EMC) in the field of electric propulsion (EP). To complete previous investigations, the emissions of a fully operating radio-frequency thruster (RIT)--including its extracted ion beam--were numerically analyzed. The ion beam was simulated and investigated with various characteristics. The simulations were performed by means of transient co-simulation. It is clear that the ion beam had a significant impact on the thruster emissions. Properties such as divergence angle and the conductivity of the beam, which can be directly attributed to the operating point of the plasma discharge inside the thruster, play a major role. The next steps will be to bring together all the knowledge gained about the emissions of the individual thruster components as well as the peripheral electronics. [ABSTRACT FROM AUTHOR]

Using the example of an electron source with a plasma cathode based on a low-pressure arc discharge with grid stabilization of the cathode/emission plasma boundary and an open anode/beam plasma boundary, a mechanism is described for increasing the electrical strength of a high-voltage accelerating gap by introducing a series negative current feedback (NCF) in the accelerating interval, which makes it possible to level out uncontrolled bursts of the beam current during its pulse. The introduction of NCF is achieved by using a special electrode in the space of the plasma emitter connected through a resistance to the anode of the arc discharge, and the main task of which is to intercept accelerated ions penetrating into the emitter from the high-voltage accelerating gap, due to which the current of electron emission from the arc discharge plasma decreases by a value proportional to the ion current in the accelerating gap. Since most sources and accelerators of electrons with plasma cathodes based on discharges of various types have a similar principle of operation, the use of this method will not only expand the limiting parameters of the generated electron beams, but also increase the stability of the operation of such electron sources, and, accordingly, beam irradiation of various materials and products. [ABSTRACT FROM AUTHOR]

The article presents the results of studies of the features and regularities of high-intensity nitrogen ion implantation into titanium using repetitively-pulsed beams with high average power densities. It is shown that the method of low-energy high-intensity nitrogen ion implantation at current densities of 180, 140, 60, and 10 mA/cm2 makes it possible to obtain wide ion-doped layers in titanium. The regularities of changes in both thickness and elemental composition of ion-doped layers depending on the ion current density have been established. It has been established that a wide diffusion layer is observed at ion current densities from 60 to 180 mA/cm2. Nitrogen concentration in the diffusion layer increases with an increase in the ion current density. The article presents the transmission electron microscopy data showing that the modified layers at a depth of 10 μm consist of α-Ti, in the volume of which nanosized particles of δ-TiN with average size of 15.4 nm crystallize. [ABSTRACT FROM AUTHOR]

The history of space debris research problem development is presented. The analysis of current state of space debris in near-Earth space is carried out, prerequisites for further growth space debris in near-Earth space are shown. Concrete examples of solving problems of space debris mitigation and protecting spacecraft are demonstrated. For one of the most clogged areas of geostationary orbit, in which there are no natural factors of objects leaving, formed scientific and technical groundwork for implementation of space debris active removal of objects project with using a service spacecraft with an ion beam injection system is considered. The role and contribution of development participants in creation of scientific and technical groundwork are indicated. The advantages of proposed method of remote impact on space objects and technical aspects of the project implementation are shown. It is proposed to use organizational form of promising projects to reduce anthropogenic impact on near-Earth space in the form of a Consortium consisting of scientific, educational and industrial partners. Within framework of this form of interaction, solution of a set of tasks is provided both for creation of new promising rocket and space technology and for the education of personnel for rocket and space industry.

The most common primary intraocular childhood cancer that affects children's and adults' vision worldwide is retinoblastoma. It is uveal melanoma when contrasting and contrasting with adults. It is a lethal tumor that has the potential to enlarge and destroy the eye and the structures that surround it. As a result, early detection of retinoblastoma in young children is essential. The research's primary impact is the identification of retinal tumor cells. It's also important to determine the tumor's stages and group. Ophthalmologists can better predict and diagnose retinoblastoma cancer at an earlier stage based on the proposed systems. Utilizing machine learning techniques, this study proposes a novel technique for detecting retinoblastoma tumors utilizing radioactive polymeric material in Nanostructure analysis with ion beam based raman spectroscopy. The region of the tumor is examined using raman spectroscopy, and its characteristics are then extracted and categorized. Convolutional Principal kernel networks are used for the tumor feature extraction, and an ensemble of multilayer Q-regressive back propagation networks is used for the classification. For various retinoblastoma datasets, the experimental analysis is conducted in terms of training accuracy, RMSE, F_measure, recall, and AUC. The proposed technique attained training accuracy of 95%, RMSE of 55%, F_measure of 65%, recall of 58%, AUC of 49%. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) thin foils were deposited on silicon and aluminum substrates and then irradiated in vacuum with 300 keV helium and argon ion beams at room temperature and at fluences ranging between 5 × 1014 ions/cm2 and 1016 ions/cm2. Attenuated total reflectance (ATR) coupled to the Fourier-transform infrared (FTIR) spectroscopy, μ-Raman spectroscopy, X-ray diffraction (XRD) and other analyses, such as Rutherford backscattering (RBS) of alpha particles, energy-dispersive X-ray (EDX) fluorescence, elastic recoil detection analysis (ERDA), scanning electron microscopy (SEM) and contact angle measurements, were used to study the effect of ion irradiation in GO. Such analytical techniques have indicated that the Ar ion implantation at high fluence may induce diamond-like-carbon (DLC) phases in the superficial irradiated layers. ATR-FTIR spectroscopy has evinced a partial removal of the oxygen functional groups with the ion fluence, indicating a GO reduction, and the presence of C=C chemical bonds when Ar irradiation is employed. Raman spectra analysis has pointed out a different behavior of GO by changing the type of ion. In fact, irradiation with 300 keV He ions induced a gradual GO reduction which increased with fluence, while the 300 keV Ar ions implantation also produced DLC, whose formation was promoted by the high energy release into GO from the Ar ions. The presence of some diamond-like crystalline phases onto the surface of the GO foil irradiated with 300 keV Ar+ ions at a fluence of 1016 ions/cm2 is also indicated by XRD spectra. RBS and EDX analyses confirm the beam-induced GO reduction from the C/O atomic ratio deduced value that grows with the He and Ar irradiations and assumes, at the same beam fluence, the highest value with the Ar+ ions. The highest carbon concentration in the Ar-irradiated rGO surface is also indicated by SEM images. The minor presence of hydrogen in the reduced GO foils has been evinced by ERDA spectrometry according to which this reduction is stronger for the Ar ion irradiation. At the highest irradiated Ar+ fluence, drastic changes on the GO surface properties have been also observed by means of wettability measurements in agreement with the suggested presence of DLCs. [ABSTRACT FROM AUTHOR]

Small mN-class gridded ion thrusters are usually tested in a vacuum chamber without the use of a neutralizer, relying on self-neutralization of the ion beam due to interaction with facility walls. Langmuir probe measurements performed immediately downstream of such a thruster reveal values of the plasma potential of several hundreds of volts. If this locally very high potential indeed exists, it would have significant impact on the erosion rate of RIT grids and thus reduce the lifetime of thrusters compared to the generally accepted plasma potential of a few tens of volts. Further measurements performed with a movable Langmuir and emissive probes indicate that the probe mount violates the ability of the ion beam to self-neutralize. This is concluded due to dependence of the measured potential value on the degree of neutralization introduced in the experiment. Particle-in-cell and direct-simulation Monte Carlo simulations of the ion beam corresponding to experimental conditions (ion energy EXe+=1.5 keV and ion beam current IXe+=17 mA) are carried out to determine the phenomena responsible for the self-neutralization; mainly, reactions with neutral species such as ionization by electron or ion impact and secondary electron emission (SEE) from the facility walls are compared. Reasonable agreement with measurements is achieved, and SEE is determined to be the primary source of electrons, indicating that facility and measurement disturbance effects majorly influence testing of (non-neutralized) ion beams. Further, limitations of the applicability of probe diagnostics on non-neutralized ion beams are described.

The results of synthesis and electromagnetic calculation of a hybrid quadrupole lens for a proton linear accelerator of the DARIA compact neutron source are presented. The lens includes a permanent magnet quadrupole with a fixed magnetic field gradient and an auxiliary electromagnetic quadrupole excited by a pulsed current. The permanent magnet quadrupole is made of a radiation resistant rare-earth magnet and the electromagnetic quadrupole is designed to compensate for permanent magnet magnetization losses resulting from radiation degradation as neutron fluence accumulates during accelerator operation. A hybrid quadrupole lens can be applied for fast adjustment of the focusing channel as well as for transporting the accelerated ion beams with different ion mass-to-charge ratios. [ABSTRACT FROM AUTHOR]

The design of the DARIA compact neutron source based on a linear resonant proton accelerator is aimed at creating a serial installation capable of providing the Russian scientific community with pulsed neutron beams with intensities comparable to those of research nuclear reactors. The absence of fissile material makes it possible to significantly reduce the radiation-safety requirements for such installations and, consequently, to place them at the site of leading scientific centers and universities that train specialists in the field of neutron physics. Under a grant from the Ministry of Science and Higher Education of the Russian Federation, key elements of the installation are being developed. The design and sequence of manufacturing for a full-scale model of an accelerator section with radio-frequency quadrupole focusing and a cavity with a drift-tube linac are presented. [ABSTRACT FROM AUTHOR]

A model for the simulation of ion beam extraction from an electron-cyclotron resonance ion source is proposed. It is based on the simple fact that charged particles follow magnetic field lines. Therefore, magnetic field lines are used to generate initial conditions for ray-tracing. This model reproduces in simulation experimentally obtained results. The importance of correlations in phase-space caused by the magnetic field is shown in the simulation. This model also describes the physics of space-charge and its compensation in the extracted (fast) ion beam by low-energy electrons. Simulation provides the possibility to test theoretical assumptions, as well as to optimize technical designs.

Objective: A procedure has been proposed for patient-specific QA that, instead of comparing a measurement to the planned dose, compares the dose calculated by an independent system to the dose calculated by the planning system. It is still prudent, however, to check the accuracy of the beam delivery. For this purpose, the DICOM records from the first treatment fraction can be compared to the planned treatment using an in-house developed planning system. Methods: Totally 1,398 patient portals were subjected to the new QA procedure. The dose distribution for each portal was first recalculated on a water phantom by two treatment planning systems and the dose distributions were compared. When agreement was observed, the patient was allowed to start treatment without a measurement. The record from the first day was imported into an in-house planning system which was used to evaluate the delivery for errors and calculate the delivered dose distribution and compare it to the planned dose distribution. Results: A total of 266 portals passed a strict comparison between the clinical and QA dose calculations and directly used for treatment without measurements. For those portals, the comparison of the delivery records to the plan showed that 99% of spot positions deviated less than 0.2 ​mm and 99.7% of spot metersets deviated by less than 0.3%. On the other hand, 64 portals showed spot size deviations greater than the tolerance of ± 15% with some as large as ±25%. For 32 portals in which the record was used to calculate the delivered dose distribution, the Gamma passing rates between the planned and delivered distributions were always above 95% using a 2% dose difference and 2 ​mm distance-to-agreement criteria. Conclusions: The new QA process has been implemented slowly with strict constraints. The amount of beam time required has been reduced while maintaining safety.

Objective: To verify the accuracy of an independent dose calculation method, as incorporated into an in-house developed treatment planning system (TPS), for performing quality assurance of dose distributions delivered to a water phantom planned by a clinical TPS. Methods: A Monte Carlo based track repeating algorithm was incorporated into an in-house treatment planning system for proton and carbon ion beams. Calculations were performed in a flat water phantom for both a traditional pencil beam algorithm and a new Monte Carlo algorithm, and then compared to measurements made at multiple depths with a 2D ionization array for 44 patient portals. The comparisons utilized a Gamma analysis. Results: A total of 124 measurements were performed for proton and carbon ion patient portals. Using a small Gamma criteria of 2%/2 ​mm, an average of 93% and 97% of measurement points passed for each portal for pencil beam and Monte Carlo calculations, respectively. The passing rate was substantially higher for Monte Carlo calculations than for pencil beam calculations for portals that used a range shifter. Conclusions: The implemented independent method has been verified against measurements. The high passing rate with small tolerances leads to the possibility of reducing the number of required quality assurance measurements.

Objective: To describe the major categories of components of an in-house treatment information, management, and planning system (TIMPS®) that were designed and built to optimize the planning process. Methods: The system was designed, from the beginning, to manage the multi-user complex process of planning and delivering external beam treatments with the eventual goal of providing one-day planning, multiple radiation modality optimization, robust optimization, 4D planning, daily adaptive treatments, and treatment verification and reconstruction. A Monte Carlo based track repeating algorithm was chosen for dose simulations. The user interface was based on web applications. Results: The first set of released tools included task queuing, followed by resource scheduling calendars and planning aims. Later releases included tools for image registration, manipulating motion profiles and 4D images, segmentation, PET simulation, and portal QA. Currently under testing are plan optimization and biophysical models. Conclusions: The in-house TIMPS first entered clinical service in April of 2017 with new tools added every few months. Since implementation, the time for planning has decreased simultaneously with a reduction of errors.

Objective: To determine under what conditions and criteria comparisons between calculations made with the current clinical treatment planning system (Syngo) and an in-house built TPS (TIMPS) would allow skipping of in-beam portal-specific measurements. Methods: Measurements were made with an array of 24 ion chambers in a water phantom for 227 proton and 313 carbon ion portals with and without a range shifter (RS). These measurements were compared with calculations performed with Syngo and TIMPS using metrics of average dose difference and Gamma index. Results: For proton portals without RS, if a Gamma comparison between TIMPS and Syngo passed using criteria of 90% of tested points being within 3% and 3 ​mm, then 74% of measurements would agree with both TIMPS and Syngo. For proton portals with RS, more than 80% of measurements would agree with both calculations using the same criteria. For carbon ion portals without RS, if a Gamma evaluation between TIMPS and Syngo passed with criteria of 90% of tested points being within 2% and 2 ​mm, 85% of measurements would agree with both calculations. For carbon ion portals with RS, if a Gamma evaluation between TIMPS and Syngo passed with criteria of 90% of tested points being within 3% and 3 ​mm, 60% of measurements would agree with both calculations. Conclusions: Both the pencil beam algorithm in Syngo and the FDC algorithm in TIMPS can provide accurate dose calculations in water for most clinical portals. For about 75% of portals, physicists can perform comparisons of calculations instead of phantom measurements to verify Syngo calculations thereby saving a large amount of beam time. There are some portals, however, such as for low-energy protons without RS and high-energy carbon ions, where agreement between the two calculations and measurements are not yet satisfactory to allow the elimination of all measurements.

Objective: To develop and implement an ion beam teletherapy verification system based upon simulations of induced radioactivity and comparison with patient positron emission tomography (PET) scans. Methods: A Monte Carlo algorithm was integrated into an in-house built treatment, information, management, and planning system (TIMPS®) to calculate distributions of positron emitters induced by ion beams. These distributions are processed to simulate PET images taking into account positron diffusion, radioactive decay, biological washout, and detector blurring. Additional tools were developed to register simulated PET images with planning CT images and perform comparisons of measured and simulated PET images. Results: Production cross-sections were generated for various isotopes and materials. Treatment plans for several different body sites were used to verify the functioning and utility of the new tools for both proton and carbon ion beams. Conclusions: Several tools have been developed to simulate PET scans of patients irradiated with ion beams and compare the simulated images to measurements. After commissioning and implementation into the clinic, the appropriate sizes for margins that account for uncertainties may be investigated.

Ion beam‐dusty plasma interaction leads to significant changes in the dispersion relation of shear Alfven wave depending on the beam, dust grain, and plasma parameters. Hydrogen ion beam particles interact with the shear Alfven wave via cyclotron interaction when they counter‐propagate with the wave and they can also interact with the co‐propagating wave via Cerenkov interaction. The interaction causes beam as well as plasma density fluctuations and gives rise to perpendicular currents. We have analytically obtained the dispersion relation and the growth/damping rate expressions for obliquely propagating shear Alfven waves in dusty plasma. The effect of beam velocity, magnetic field, wave number, dust particle density, and dust charge fluctuations are discussed. It is shown that both the wave frequency and the maximum growth rate decrease with an increase in beam velocity and the variations are different for parallel and perpendicular wave numbers. The dust particles enhance the frequency and maximum growth rate while the dust charge fluctuations induce damping. The results are in good agreement with the experimental observations. [ABSTRACT FROM AUTHOR]

In this current study, hydrogen ions of fluence 5 × 1017, 10 × 1017 as well as 15 × 1017 ions.cm− 2 were irradiating PVA/ZnO films for applying the irradiated samples in optoelectronics devices. The XRD, SEM, as well as FTIR techniques were used to record the effects of hydrogen ions on the structures, morphologies, as well as functional group of the irradiated films respectively. The FTIR and XRD employed the successful fabricated of the PVA/ZnO composite that made of polyvinyl alcohol (PVA) and zinc oxide nanoparticles (ZnONPs). On the other hand, UV-Vis spectroscopic analysis was utilized to examine optical properties of the PVA/ZnO. The bandgap, absorption edge, as well as Urbach energies of pure and ion-exposed films were calculated via the Tauc's formula. By increasing hydrogen ions to 15 × 1017 ions.cm− 2, the Urbach tail increased from 0.36 to 0.43 eV and the optical gap decreased form 2.86 to 2.74 eV. Additionally, the non-linear dispersion properties and optical susceptibilities of pure and irradiated samples were recorded. The irradiated PVA/ZnO samples exhibited enhanced structural and linear/nonlinear optical characteristics, making them suitable for use in optoelectronics. [ABSTRACT FROM AUTHOR]

In recent years, ion-beam irradiation (IBI) has been proven an effective approach for the mass production of nanopatterns on the surfaces of wide range of materials. However, the role of different ion beam masses (Ar and Kr) needs attention for potential use of ripple patterns in wettability applications. In this work, we present a systematic study on the growth of ripple patterns for the two different projectiles of Ar+ and Kr+ and, furthermore, their anisotropic behaviour of wettability. An increase in wavelength and amplitude of ripples on Si (100) surface with increase in ion beam energy from 60 to100 keV has been observed. Wavelength of ripples is found to be higher for the Ar+ as compared to Kr+ at each irradiation energy value. A power law dependency of ripple wavelength on ion beam energy has been proposed as λ ~ Em, where 'm' is found to be 0.48 ± 0.0008 for Ar+ and 0.85 ± 0.06 for Kr+ beam, which shows the importance of mass re-distribution in ripples growth. Furthermore, observed variation in the contact angle is found to be deviated from Wenzel's law which is attributed to a reduction in the surface free energy of ion implanted Si ripple surfaces. Hence, the near surface damage under the incorporation of Ar/Kr atoms alters the chemical composition and which is effectively controlling the anisotropic wettability of ripples. [ABSTRACT FROM AUTHOR]

Contactless transportation of a passive object by an ion beam generated by an active spacecraft's thruster is a promising way of space debris removal. The study proposes a modification of the ion beam shepherd concept using an array of impulse transfer thrusters. The multi-beam scheme provides significant increase the generated ion force, which reduces a space debris object deorbit time, thereby reducing the probability of its collision with other orbital objects. The aim of the work is to study the possibility of using several ion beams for effective contactless transportation of a space debris object. Controlling the angular motion of the object permits orientation of the object to maximize the generated ion force. The article proposes a control law for impulse transfer thrusters, which is based on the calculation of the energy of the object's unperturbed motion, and two control schemes that implement this law: (1) relay control, which implies turning the thruster on and off, and (2) ion beam axis direction control for one of the thrusters. For a space debris object of a cylindrical shape, a comparison of the time and fuel costs required for deorbiting the object using one, two, and three impulse transfer thrusters is made. It is shown that the addition of thrusters significantly reduces the descent time, but has little effect on the mass of required fuel. For the case of two engines, the best angle of ion beams axes direction and the most preferable angular motion mode are determined. Numerical simulation of space debris removal is carried out for the case when the space debris object is in the least favorable mode of angular motion and the proposed control schemes are used. The ion beam direction control scheme showed better results than the relay scheme. The use of multiple ion beams opens up new possibilities for creating new ion beam shepherd spacecraft design and developing new control methods and laws. [ABSTRACT FROM AUTHOR]

In this study, a PANI/Cu nanocomposite films are prepare using ion sputtering technique. Then PANI/Cu nanocomposite films are irradiated by different fluence of low energy hydrogen ion (1x1016, 4x1016, and 8x1016 ion/cm2). The changes in crystallite structure are studied using XRD diffractometer. The dielectric properties and the energy density of the blank and irradiated films are obtained at room temperature in the frequency range of 100 to 5MHz. The measurements indicated significant changes in these parameters after hydrogen ion irradiation. The dielectric constant ε' improved from 1.5 for PANI/Cu to 6, 10 and 23 after exposed to 1x1016, 4x1016, and 8x1016 ion/cm². Moreover, the conductivity energy density is improved from 1.6x10-5 for unirradiated to 2.1x10-5, 4.8x10-5, and 1.5x10-4 for irradiated films. The results confirmed an improving in electric properties and energy density of the irradiated PANI/Cu nanocomposite films, which can using these films in wide range of application such as super-capacitor and microelectronic devices. [ABSTRACT FROM AUTHOR]

Mutation breeding through irradiation has been applied to several varieties and genetic resources since the discovery of the use of X-rays for inducing mutations in plants by Stadler in 1928. A heavy ion beam with high linear energy transfer (LET) shows a higher relative biological effectiveness (RBE), and it is more effective in inducing plant mutations than low LET radiations, such as X-rays, gamma rays, and electrons. Since early 1990s, several plant breeding programs in Japan have used heavy ion beams from accelerators. These beams impart a high energy effect on a local target; therefore, they induce a higher number of single and double strand DNA breaks. In addition, they induce a large number of DNA deletions than low LET radiations. Therefore, a heavy ion beam is superior to low LET radiations in terms of induction rate and the mutation spectrum. In Korea, a heavy ion accelerator that can be used for breeding is under construction. However, a large-capacity proton accelerator (KOMAC: Korea Multi-purpose Accelerator Complex) was built recently, and it is a pioneer step in breeding research worldwide. This review summarizes the basic characteristics, successful research achievements, and the prospect of application of high LET accelerator beams in plant mutation breeding. [ABSTRACT FROM AUTHOR]

Two ancient Roman silver coins dating back to the 3rd–4th century AD are studied. A set of modern micro- and nondestructive analytical techniques, namely, a focused ion beam, scanning electron microscopy, energy-dispersive X-ray microanalysis, micro-X-ray fluorescence analysis, neutron-radiation analysis, and other methods is used. Research shows that Ag–Cu and Ag–Cu–Pb–Sn alloys were used, which were common in the prosperous years of the Roman Empire when the Romans produced alloys with a relatively high silver content for both outer layers and the inner core of coins. Surface silvering processes were used in different crisis periods during the reign of Antonine. It is established that even during the crisis, the Romans produced high quality Antoniniani, attempting to improve the silvering procedure using silver amalgam (Hg–Ag). Mercury is detected in the surface silver layer of the coins. A porous morphology of the coin surface is also revealed, which might be the result of an uncontrolled heating process and the removal of mercury through boiling. [ABSTRACT FROM AUTHOR]

Purpose: Reporting on the first implementation of a proton dedicated commercial device (IBA Sphinx/Lynx) for daily Quality Assurance (QA) of scanned proton and carbon ion beams. Methods: Daily QA trendlines over more than 3 years for protons and more than 2 years for carbon ions have been acquired. Key daily QA parameters were reviewed, namely the spot size and position, beam range, Bragg peak width, coincidence (between beam and imaging system isocenters), homogeneity and dose. Results: The performance of the QA equipment for protons and carbon ions was evaluated. Daily QA trendlines allowed us to detect machine performance drifts and changes. The definition of tolerances and action levels is provided and compared with levels used in the literature. Conclusion: The device has been successfully implemented for routine daily QA activities in a dual particle therapy facility for more than 2 years. It improved the efficiency of daily QA and provides a comprehensive QA process. [ABSTRACT FROM AUTHOR]

A two-dimensional beam monitoring detector named π 2 has been developed and tested at the Bern University Hospital, using an 18 MeV proton beam provided by a medical cyclotron. This non-destructive device utilises a scintillating compound (P47 phosphor) coated onto a thin aluminium foil that is angled at 45 ∘ with respect to the beam axis. The scintillating light produced when the beam passes through the foil is captured by a CMOS camera, resulting in a two-dimensional image of the beam profile. Custom software is then used to analyse the image and extract valuable information about the beam's position, shape, and intensity. The focus of the experimental work was on characterising the performance of the π 2 with the 18 MeV proton beam. The linearity of the detector's output signal was evaluated for proton fluxes ranging from 2 · 10 10 cm − 2 · s − 1 to 5 · 10 11 cm − 2 · s − 1 . Furthermore, the beam profiles measured with the π 2 were found to be consistent with reference measurements obtained using alternative beam monitors. Additionally, the experiments also involved studying the beam scattering caused by the foil and scintillating layer. Finally, in a long-term radiation test, the detector demonstrated a stable response up to an integrated proton flux of 3 · 10 15 cm − 2 . The π 2 is currently being used at the Bern cyclotron for monitoring beams in the development of new methods for medical radioisotope production and for radiation hardness studies. The π 2 has potential applications in several fields that involve the use of accelerated ions, such as cancer particle therapy, medical radioisotope production and radiation hardness studies. [ABSTRACT FROM AUTHOR]

Attention to the method of removing large space debris objects by impacting them with an ion beam has not waned over the past 10 years. The application of this method to the space debris removal from the protected area of the Geostationary Earth Orbit (GEO) seems to be the most effective. This is due to a low energy consumption for removing an object to a safe orbit with ΔV≃11 m/s, which allows the removal of several objects by a single spacecraft. A service spacecraft can be developed for this purpose based on the TelSat geostationary communication satellite technology. At the same time, one of the problematic issues remains that is the development of an injector of a weakly divergent ion beam. The ion beam divergence during injection into the vacuum occurs under the insuperable influence of the ambipolar electric field acting in the beam volume. At the same time, the beam behavior depends on the initial divergence angle stipulated by the conditions of beam formation by the electrostatic acceleration system. This paper considers the results of calculated and experimental studies for the peculiarities of the formation of an ion beam in an ion extraction system with slit and round apertures. The dependence of the initial divergence half-angle on the beam perveance for both geometries was defined. In the operation of the injector designed for the space debris removal, it is necessary to ensure stability of the geometry of the ion-extraction system, which is subject to uneven thermal loading. The resulting thermomechanical deformations of the grids in the technology of ion thrusters are parried by giving the grids a plate shape. Therefore, flat grids made of a carbon-carbon composite material of a new type were used in experiments, which avoided noticeable deformations. The results of experimental investigation of the prototype of ion injector with two configurations of carbon grids (with round and slit perforation) and with the initial divergence half-angle of 2°-4° are given in this paper. The thrust control of an ion beam by changing of the screen grid potential under the condition of a constant beam perveance is considered. It is shown that such regulation is associated with a change in the Mach number, which affects the beam divergence. As an example, the calculation of the dependence of the coefficient k on the distance to the removing object is given, which is considered to be a spent satellite SUPERBIRD-A. • The minimum angle of the ion beam divergence of the ion injector were achieved. • A comparison of ion injector with slit-type and round-type aperture perforation. • The value of coefficient of thrust transfer to the object to be removed. [ABSTRACT FROM AUTHOR]

Introduction: This study focuses on the detection of rhodamine-6G using surface-enhanced Raman scattering (SERS) on gold nanostructures (AuNS) of different sizes. Ion beam irradiation has been carried out to tune the size of AuNS and investigate the underlying mechanisms of sputtering and diffusion that govern their growth. Additionally, the study established a correlation between fractal growth parameters, water contact angle, and SERS detection of R6G. The results of this study offer new insights into the mechanisms of SERS detection on roughened metallic surfaces.Methods: Thermal evaporation was used to deposit an Au thin film on a glass substrate. Subsequent 10 keV Ar+ irradiation was done on Au thin film for fluences ranging from 3×1014 to 3×1016 ions/cm2 to tune the size of AuNS. Rutherford backscattering spectroscopy (RBS) was used to confirm that the decrease in Au concentration under ion beam sputtering was responsible for the tuning in size and structure of AuNS. Fractal dimension (Df) and interface width (w) were used as statistical parameters to control the wettable characteristics of the AuNS surfaces.Results and discussion: The researchers found that the growth of AuNS was governed by ion beam induced sputtering and diffusion mechanisms. They established a correlation between fractal growth parameters, water contact angle, and SERS detection of R6G. They found that a higher surface coverage area of Au NPs with lower fractal dimensions and water contact angles favoured the SERS detection of R6G. This study provides new insights into the mechanisms of SERS detection on roughened metallic surfaces. It is found that the growth of AuNS was governed by ion beam-induced sputtering and diffusion mechanisms, and established a correlation between fractal growth parameters, water contact angle, and SERS detection of R6G. The findings of this study may have applications in the development of more sensitive and efficient SERS-based chemical sensors.