Ray Beam Research Articles

Comparison and Characterization of Phenotypic and Genomic Mutations Induced by a Carbon-Ion Beam and Gamma-ray Irradiation in Soybean (Glycine max (L.) Merr.).

Soybean (Glycine max (L.) Merr.) is a nutritious crop that can provide both oil and protein. A variety of mutagenesis methods have been proposed to obtain better soybean germplasm resources. Among the different types of physical mutagens, carbon-ion beams are considered to be highly efficient with high linear energy transfer (LET), and gamma rays have also been widely used for mutation breeding. However, systematic knowledge of the mutagenic effects of these two mutagens during development and on phenotypic and genomic mutations has not yet been elucidated in soybean. To this end, dry seeds of Williams 82 soybean were irradiated with a carbon-ion beam and gamma rays. The biological effects of the M1 generation included changes in survival rate, yield and fertility. Compared with gamma rays, the relative biological effectiveness (RBE) of the carbon-ion beams was between 2.5 and 3.0. Furthermore, the optimal dose for soybean was determined to be 101 Gy to 115 Gy when using the carbon-ion beam, and it was 263 Gy to 343 Gy when using gamma rays. A total of 325 screened mutant families were detected from out of 2000 M2 families using the carbon-ion beam, and 336 screened mutant families were found using gamma rays. Regarding the screened phenotypic M2 mutations, the proportion of low-frequency phenotypic mutations was 23.4% when using a carbon ion beam, and the proportion was 9.8% when using gamma rays. Low-frequency phenotypic mutations were easily obtained with the carbon-ion beam. After screening the mutations from the M2 generation, their stability was verified, and the genome mutation spectrum of M3 was systemically profiled. A variety of mutations, including single-base substitutions (SBSs), insertion-deletion mutations (INDELs), multinucleotide variants (MNVs) and structural variants (SVs) were detected with both carbon-ion beam irradiation and gamma-ray irradiation. Overall, 1988 homozygous mutations and 9695 homozygous + heterozygous genotype mutations were detected when using the carbon-ion beam. Additionally, 5279 homozygous mutations and 14,243 homozygous + heterozygous genotype mutations were detected when using gamma rays. The carbon-ion beam, which resulted in low levels of background mutations, has the potential to alleviate the problems caused by linkage drag in soybean mutation breeding. Regarding the genomic mutations, when using the carbon-ion beam, the proportion of homozygous-genotype SVs was 0.45%, and that of homozygous + heterozygous-genotype SVs was 6.27%; meanwhile, the proportions were 0.04% and 4.04% when using gamma rays. A higher proportion of SVs were detected when using the carbon ion beam. The gene effects of missense mutations were greater under carbon-ion beam irradiation, and the gene effects of nonsense mutations were greater under gamma-ray irradiation, which meant that the changes in the amino acid sequences were different between the carbon-ion beam and gamma rays. Taken together, our results demonstrate that both carbon-ion beam and gamma rays are effective techniques for rapid mutation breeding in soybean. If one would like to obtain mutations with a low-frequency phenotype, low levels of background genomic mutations and mutations with a higher proportion of SVs, carbon-ion beams are the best choice.

Three-component lens zoom-afocal transfocal systems

Parametric synthesis of zoom-afocal optical systems for zooms. Development of an algorithm for overall calculation of three-component zoom-afocal systems taking into account their overall limitations, ensuring the required range of change in angular magnification and field of view of the zoom lens, admissible vignetting of extreme beams of rays when changing the field of view in the entire specified range. Synthesis of an afocal system for a fixed lens, the entrance pupil of which is behind the afocal system. Creation of a universal analytical and suitable for computer automation algorithm for calculating the optical and dimensional parameters of the components of zoom-afocal three-component zoom systems. The zoom-afocal system is represented by thin components. A system of equations is created in which the distances between the components are unknown. The values of these distances are determined from the equations, which provide the required values of the angular magnification and zero optical power of the afocal system. At the same time, the values of the optical powers of the components and their ratio should ensure positive values of the distances between them. Using the formulas for the angles and heights of zero rays on the components of the system and taking into account the permissible vignetting of the beam from the edge of the field of view, the required light diameters of the components are determined. The obtained analytical dependencies make it possible to determine the focal distances of its components and their relative location over the entire range of the desired change in angular magnification based on the initial data on the admissible longitudinal and transverse dimensions of the afocal system. It was established that the afocal system has a maximum axial length at an angular magnification of one. The first component needs the largest light diameter. The diameter of this component reaches its largest value when the angular increase approaches unity. The obtained results make it possible to analytically carry out a parametric synthesis of three-component zoom-afocal systems, taking into account the requirements for their dimensions, the range of changes in the angular magnification and the permissible vignetting of the beam beams from the edge of the field of view.

Measuring the cross section of the N15(α,γ)19F reaction using a single-fluid bubble chamber

$^{15}$N($\alpha$,$\gamma$)$^{19}$F is believed to be the primary means of stellar nucleosynthesis of fluorine. Here we present the use of a single-fluid bubble chamber to measure the cross section of the time-inverse photo-dissociation reaction. The method benefits from a luminosity increase of several orders of magnitude due to the use of a thicker liquid target -- when compared to thin films or gas targets -- and from the reciprocity theorem. We discuss the results of an experiment at the Thomas Jefferson National Accelerator Facility, where the cross section of the photodisintegration process $^{19}$F($\gamma$, $\alpha$)$^{15}$N was measured by bombarding a superheated fluid of C$_3$F$_8$ with bremsstrahlung $\gamma$-rays produced by impinging a 4 - 5.5 MeV electron beam on a Cu radiator. From the photodissociation yield the cross section was extracted by performing a convolution with a Monte Carlo-generated $\gamma$-ray beam spectrum. The measurement produced a cross section that was then time inverted using the reciprocity theorem. The cross section for the $^{15}$N($\alpha$,$\gamma$)$^{19}$F reaction was determined down to a value in the range of hundreds of picobarns. With further improvements of the experimental setup the technique could potentially push cross section measurements down to the single picobarn range.

ХАРАКТЕРИСТИКА ПОВРЕЖДЕНИЯ МОЗГА ПОСЛЕ γ, n-ОБЛУЧЕНИЯ ГОЛОВЫ МЫШЕЙ И МОДИФИКАЦИЯ УРОВНЯ НЕЙРОВОСПАЛЕНИЯ ПРИ ВВЕДЕНИИ ЛАКТОФЕРРИНА

Purpose: To investigate the effect of γ, n-irradiation of the mice head on the brain cells damage, behavior and cognition, and to examine the possibility of using lactoferrin (LF) to alleviate radiation-induced impairments. Material and methods: Mice heads were irradiated in a beam of neutrons and gamma rays from the IR-8 nuclear reactor. The brain cells of control and irradiated mice were isolated using Percoll. Neurons and resting and activated microglia cells were analyzed using the fluorescently labeled antibodies and flow cytometry. The level of DNA double-strand breaks in neurons was determined by γH2AX histone content. Cytokine gene expression in the hippocampus was studied by RT-PCR. Behavior and cognitive functions were studied using the open field, Morris water maze and novel object recognition tests. LF was isolated from female colostrum by preparative ion-exchange chromatography and purified by affinity chromatography on heparin-sepharose. Results: γ, n-Irradiation of the mice head at a dose of 1.5 Gy led to an increase in the level of DNA double-strand breaks in neurons. Twenty-four hours after irradiation the total number of cells and the number of neurons in the isolated fraction of brain cells decreased, but the number of microglial cells remained unchanged. The number of resting and activated microglia did not change within 3–72 h after γ, n-irradiation. The expression level of the TNFα, IL-1β, and IL-6 genes increased 2 months after γ, n-irradiation of the mice head at a dose of 1.5 Gy, indicating the development of neuroinflammation. At this time, irradiated mice demonstrated the anxiety-like behavior and impaired spatial and recognition memory. A single i.p. administration of human LF to mice immediately after γ, n-irradiation of the head did not affect the observed radiation-induced disturbances, but decreased the gene expression levels of TNFα, IL-1β and IL-6 pro-inflammatory cytokines and increased the gene expression level of TGFβ anti-inflammatory cytokine in the hippocampus 2 months after radiation exposure. The obtained results indicate a partial decrease in the level of hippocampal neuroinflammation of irradiated animals treated with LF. Conclusion: γ, n-Irradiation of the mice head at a dose of 1.5 Gy leads to DNA damage of neurons and the decrease in the number of neurons. Microglia cells are more resistant to such radiation exposure. Late after head-only γ, n-irradiation, mice develop neuroinflammation, which is detected by an increase in the pro-inflammatory cytokine gene expression in the hippocampus and also by anxiety-like behavior and impaired cognitive functions. A single LF administration leads to a partial decrease in the neuroinflammation level, but does not affect the other studied parameters. The optimal dosing regimen of LF remains to be determined to preserve cognitive functions after γ, n-irradiation of the brain.

Compton scattering geometry: a tool to study radiation interaction characteristics of rare earth compounds doped in low-Z organic compound

Abstract The present measurements comprise of Compton scattering technique at six energies from 0.242 MeV to 0.402 MeV (not available from conventional radioisotopes) by scattering of primary gamma photon beam of 0.662 MeV energy from cylindrical aluminium target at different scattering angles. Two inorganic (rare-earth) compounds, Lanthanum (3+) nitrate hexahydrate and Samarium (3+) nitrate hexahydrate in a Low-Z organic solvent (acetone), have shown certain radiation interaction characteristics are the subject of study. The collimated beam of scattered gamma rays impinges on the plastic container having solution of rare earth compounds in the acetone of different concentrations. The transmitted gamma ray beam is detected by a well-collimated 2″ × 2″ NaI(Tl) scintillation detector and is analysed by a PC-based ORTEC Mastero-32 MCA. Attenuation coefficients along with some shielding parameters i.e. molar extinction coefficients, half value layer, tenth value layer and mean free path are evaluated. Besides this, Computed Tomography numbers and photon interaction cross-sections (photoelectric, coherent and incoherent) are also determined. The measured values of these parameters are compared with WinXCom software package’s values and are found to be in good agreement. The available data on rare earth salts’ solutions, in the current measurements, is scientifically important in nuclear and radiation physics, bridging the gap in which radiation workers do not have access to such data.

Fast shaping control of x ray beams using a closed-loop adaptive bimorph deformable mirror

High-speed adaptive correction of optics, based on real-time metrology feedback, has benefitted numerous scientific communities for several decades. However, it remains a major technological challenge to extend this concept into the hard x ray regime due to the necessity for active mirrors with single-digit nanometer height errors relative to a range of aspheric forms. We have developed a high-resolution, real-time, closed-loop “adaptive” optical system for synchrotron and x ray free electron laser (XFEL) applications. After calibration of the wavefront using x ray speckle scanning, the wavefront diagnostic was removed from the x ray beam path. Non-invasive control of the size and shape of the reflected x ray beam was then demonstrated by driving a piezoelectric deformable bimorph mirror at ∼ 1 H z . Continuous feedback was provided by a 20 kHz direct measurement of the optical surface with picometer sensitivity using an array of interferometric sensors. This enabled a non-specialist operator to reproduce a series of pre-defined x ray wavefronts, including focused or non-Gaussian profiles, such as flattop intensity or multiple split peaks with controllable separation and relative amplitude. Such changes can be applied in any order and in rapid succession without the need for invasive wavefront diagnostic sensors that block the x ray beam for scientific usage. These innovations have the potential to profoundly change how x ray focusing elements are utilized at synchrotron radiation and XFEL sources and provide unprecedented dynamic control of photon beams to aid scientific discoveries in a wide range of disciplines.

Effect of Gamma Radiation on the Processability of New and Recycled PA-6 Polymers.

The growing quantities of plastic waste have raised environmental concerns, with almost a quarter of disposed plastics being sent to landfill. This has motivated research efforts into various recycling technologies to ease dependence on fossil resources, increasing circularity. Irradiation of various kinds, such as electron beam, beta and gamma rays, has been studied in the past as a way of revamping end-of-life polymer properties. The present work focuses on the effects of gamma radiation on the processability of new and recycled polymers, which is intimately linked with their rheological properties. In this study, both virgin and recycled polymers were irradiated under different radiation doses and the effects of the radiation on their viscosity assessed and compared. Results were analyzed making use of different theoretical relationships, and the causes of the changes in rheology were investigated by means of various characterization techniques, such as GPC, FTIR, EPR and DSC. Finally, the rheological curves of all samples were fitted to the Ostwald-de Waele relationship and the dependence of its parameters on the absorbed dose fitted to a function.

Riemannian geometric modeling of underwater acoustic ray propagation—Basic theory

Underwater sound propagation models are generally established from the extrinsic perspective, that is, embedding acoustic channels in Euclidean space with a fixed coordinate system. Riemannian geometry is intrinsic for curved space, which can describe the essential properties of background manifolds. The underwater acoustic Gaussian beam is originally adopted from seismology. Till now it has been the most important method used in acoustic ray based modeling and applications. Owing to the advantages of Gaussian beam method over the traditional ray counterpart, it is the mainstream technology of ray propagation computational software such as the famous Bellhop. With the assumption of Euclidean space, it is hard to grasp the naturally curved characteristics of the Gaussian beam. In this work, we propose the Riemannian geometry theory of underwater acoustic ray propagation, and obtain the following results. 1) The Riemannian geometric intrinsic forms of the eikonal equation, paraxial ray equation and the Gaussian beam under radially symmetric acoustic propagation environments are established, which provide a Riemannian geometric interpretation of the Gaussian beam. In fact, the underwater acoustic eikonal equation is equivalent to the geodesic equation in Riemannian manifolds, and the intrinsic geometric spreading of the Gaussian beam corresponds to the lateral deviation of geodesic curve along the Jacobian field. 2) Some geometric and topological properties of acoustic ray about conjugate points and section curvature are acquired by the Jacobi field theory, indicating that the convergence of ray beam corresponds to the intersection of geodesics at the conjugate point with positive section curvature. 3) The specific modeling method under horizontal stratified and distance-related environment is presented by using the above theory. And we point out that the method proposed here is also applicable to other radially symmetric acoustic propagation environments. 4) Simulations and comparative analyses of three typical underwater acoustic propagation examples, confirm the feasibility of the Riemannian geometric model for underwater acoustic propagation, and show that the Riemannian geometric model has exact mathematical physics meaning over the Euclidean space method adopted by the Bellhop model. The basic theory given in this paper can be extended to the curved surface, three-dimensional and other complex propagation cases. And especially it lays a theoretical foundation for the further research of long-range acoustic propagation considering curvature of the earth.

Changes in the Physical Properties of the Cotton Linter Paper Irradiated by a Gamma Ray and Electron Beam

The effects of gamma ray and electron beam irradiation on paper disinfection were evaluated. The paper was irradiated with 10-100 kGy gamma rays and electron beams which were higher than the recommended dose for paper disinfection. After irradiation, the mechanical properties and color of the paper and the cellulose chain scission rate were evaluated. In the case of paper strength, it decreased after 25 kGy irradiation, whereas the discoloration of paper appeared after 10 kGy irradiation. It cannot confirm the effect on paper only with changes in mechanical strength and color in the recommended range of 0.5-10 kGy for actual paper disinfection treatment. On the other hand, even with 10 kGy irradiation, the degree of polymerization of cellulose paper was reduced by ~50%. Cotton linter paper with a degree of polymerization of about 2,000 was predicted to decrease by about 7% after being irradiated with a 1 kGy gamma ray and electron beam. To evaluate the irradiation effect on paper, it is therefore more reasonable to evaluate the degree of polymerization rather than the strength and color of the paper.

Gamma Knife Radiosurgery - A Revolutionary Modality in the Treatment of Brain Tumors

For delivering highly accurate radiation therapy with pin-point accuracy to brain tumors, radiosurgery employing Gamma Knife Radiosurgery technique is a revolutionary new armamentarium that enables delivering focused intense beam of gamma rays to brain lesions. Neither employing an actual knife nor surgery, it is called “surgery” because the results are as good, even better, than actual surgeries. Gamma Knife radiosurgery can be as effective in treating nerve conditions and blood vessel malformations as brain tumors [1] (Table 1). The tumor gradually shrinks after treatment that damages and destroys the tumor cell DNA that cannot grow or reproduce anymore.

Spectral distribution and flux of [formula omitted]-ray beams produced through Compton scattering of unsynchronized laser and electron beams

Intense, quasi-monochromatic, polarized γ-ray beams with high and tunable energy produced by Compton scattering of laser photons against relativistic electrons are used for fundamental studies and applications. Following a series of photoneutron cross section measurements in the Giant Dipole Resonance (GDR) energy region performed at the NewSUBARU synchrotron radiation facility, we have developed the eliLaBr Monte Carlo simulation code for characterization of the scattered γ-ray photon beams. The code is implemented using Geant4 and is available on the GitHub repository (https://github.com/dan-mihai-filipescu/eliLaBr). Here we report the validation of the eliLaBr code on NewSUBARU LCS γ-ray beam flux and spectral distribution data and two applications performed with it for asymmetric transverse emittance profiles electron beams, characteristic for synchrotrons.The first application is based on a systematic investigation of transverse collimator offsets relative to the laser and electron beam axis. We show that the maximum energy of the LCS γ-ray beam is altered by vertical collimator offsets, where the edge shifts towards lower energies with the increase in the offset.Secondly, using the eliLaBr code, we investigate the effect of the laser polarization plane orientation on the properties of the LCS γ-ray beams produced with asymmetric emittance electron beams. We show that:1. The use of vertically polarized lasers contributes to the preservation of the LCS γ-ray beam maximum energy edge by increasing the precision in the vertical collimator alignment.2. Under identical conditions for the electron and laser beams phase-space distributions, the energy spectrum of the scattered LCS γ-ray beam changes with the laser beam polarization plane orientation. More precisely, the use of vertically polarized laser beams slightly deteriorates the LCS γ-ray beam energy resolution.

Conditions for correcting third-order spherical aberration in a ball lens with spherical refractive index distribution

A ball lens is analyzed. The refractive index of this lens is a function of the distance from the ball center. Conditions are derived under which such a lens is free of the third-order spherical aberration given a beam of incident parallel rays.

Directed energy deposition powder stream modeling using a Gaussian beam ray representation

The powder stream from a side feed nozzle, or part of the powder stream in some coaxial nozzles, in a directed energy deposition via powder feeding (DED-PF) machine, can be modeled using a particle velocity field that has a constant downward component and a linearly increasing outward component, in proportion to the powder stream's center line distance. However, when the powder stream is subject to a force field, it was found that the shape of the powder concentration function close to the center of the powder stream diverges considerably at high degrees of focusing. This discrepancy is reduced by modeling the powder stream based on the ray representation of a Gaussian beam. Experimental results from high-speed camera particle tracking and numerically extrapolating the trajectories to the nozzle exit suggests that the statistics of the powder stream correspond to this model. A novel method to compute the particle concentration along the stream using an optical system analog, with the focusing force field modeled as the transfer matrix of a graded refractive index (GRIN) lens, is also demonstrated. This method is orders of magnitude faster than the corresponding Lagrangian simulation.

Effect of Diode-Based Transmission Detector Measurement on Dose Perturbation during Delivery of 6MV Photon

<h3>Purpose/Objective(s)</h3> Delivery dose quality assurance (QA) during treatment planning execution is the most direct and effective way to ensure that the prescribed dose is delivered accurately and the patient is irradiated safely. The purpose of this article is to evaluate the stability and sensitivity of the diode-based transmission detector (TD) installed on the beam path during radiotherapy, and analyze the effect of TD on the photon beam fluence and dose distribution. <h3>Materials/Methods</h3> The beam fluence with and without TD was measured for 6MV on a linear accelerator. The point doses at different depths (0.0cm∼15.0cm), different dose values (100MU∼500MU), different dose rates (100MU/min∼600MU/min) and different irradiation fields (3cm × 3cm∼20cm × 20cm) were measured by cylindrical three-dimensional water tank, and the transmission factors (TF) were calculated and analyzed. The percentage depth dose (PDD) and beam profile under different parameters were collected to analyze the effect of TD on ray quality and dose distribution. The effect of different irradiation fields on the γ passing rate was evaluated by a planar dosimeter. <h3>Results</h3> The diode-based TD has the high stability of 0.1% (1SD) and excellent position monitoring performance (≤0.2mm). The TF varies with the depth, dose, dose rate and irradiation fields. When the depth is 0cm, the TF has maximum value of 99.55%. For the depth of 0cm∼5cm, the TF increases with the increase of dose and dose rate (<i>R</i>=0.91, 0.75). For the depth of 5cm, the TF is least affected by dose and dose rate (1SD: 0.01%, 0.07%), and decreased with the increase of irradiation fields, 98.94% for 3cm × 3cm. When the depth is >5cm, it decreases with the dose increasing (<i>R</i>=−0.88∼−0.26), and increases with the dose rate increasing (<i>R</i>=0.78). The average TF under all the above conditions is 98.46%, that is, beam attenuation is 1.54%. The movement of the position of maximum dose depth is 0.124cm for 5cm × 5cm and 0.250cm for 3cm × 3cm to the surface of the water (0cm), otherwise ≤0.003cm. TD increases dose in build-up region, 1.49% for fields of 20cm × 20cm. TD effects ray quality (≤0.0028), beam symmetry and flatness (≤0.68%). The γ passing rate does not change under the commonly used indexes of 3%/3mm and 2%/2mm. <h3>Conclusion</h3> The diode-based TD has high stability and excellent monitoring performance. Although it has little effect on ray quality, beam symmetry, flatness and γ passing rate, it will cause beam attenuation and increase surface dose.

Towards bright gamma-ray flash generation from tailored target irradiated by multi-petawatt laser

One of the remarkable phenomena in the laser-matter interaction is the extremely efficient energy transfer to gamma -photons, that appears as a collimated gamma -ray beam. For interactions of realistic laser pulses with matter, existence of an amplified spontaneous emission pedestal plays a crucial role, since it hits the target prior to the main pulse arrival, leading to a cloud of preplasma and drilling a narrow channel inside the target. These effects significantly alter the process of gamma -photon generation. Here, we study this process by importing the outcome of magnetohydrodynamic simulations of the pedestal-target interaction into particle-in-cell simulations for describing the gamma -photon generation. It is seen that target tailoring prior the laser-target interaction plays an important positive role, enhancing the efficiency of laser pulse coupling with the target, and generating high energy electron-positron pairs. It is expected that such a gamma -photon source will be actively used in various applications in nuclear photonics, material science and astrophysical processes modelling.

Development of Direct Immobilization Technique of Ag Nanoparticles on Resin Substrates Imparting High Antibacterial and Antiviral Activities.

A new method has been developed to impart the antimicrobial activity of silver nanoparticles to resin substrates. A resin substrate immersed in an aqueous solution of silver nitrate was irradiated with gamma ray or high energy electron beams. Silver nanoparticles were successfully immobilized on the resin surface directly by chemical reactions induced by ionizing radiation. It was experimentally confirmed that various resin materials, such as acrylonitrile-butadiene-styrene, polyethylene, polypropylene, polyvinyl chloride, and polycarbonate, were applicable for this process. The effects of gamma ray or electron beam irradiation on resin substrates were almost negligible since the irradiation dose was equal or less than that used for sterilization. Despite the small amount of Ag loadings, the obtained samples showed high antibacterial and antiviral activities.

MAGNETIC SYSTEM FOR CLEANING THE GAMMA BEAM AT THE LUE-40 ELECTRON LINAC OUTPUT

The bremsstrahlung of accelerated electrons passing through a converter is used to study multiparticle photonuclear reactions. The results of calculations, numerical modeling, design, and testing of a special magnetic cleaning system to obtain a “pure” beam of bremsstrahlung quanta when studying the cross-sections of such reactions at the LUE-40 linac are presented. The system is based on commercially available permanent magnets of rectangular cross-sections. The maximum on-axis field is 0.9 T, which provides sufficient separation of the electron beam and gamma rays at a distance of more than 90 mm from the magnet.

Studies on the variation of structural and thermodynamic properties of charge coupled substituted NaxEuxCa10‐2x(PO4)6F2 solid solutions (x = 0.5–2.0)

Owing to the importance of fluorapatite matrices for immobilization of nuclear waste, a systematic study was undertaken to explore the variation of structural and thermodynamic properties of co-doped calcium fluorapatite with general formula NaxEuxCa10‐2x(PO4)6F2, where x = 0.5, 1.0,1.5 and 2.0. These solid solutions were synthesized via solid state reaction route and characterized by X-ray diffraction (XRD), Fourier Transform Infra-red spectroscopy (FTIR) and Raman spectroscopy. Rietveld refinement of powder diffraction patterns was carried out to determine detailed structures of the compounds. Thermal stability of the synthesized compounds was ascertained by Thermogravimetry (TG) and Differential Scanning Calorimetry (DSC). Thermal expansion coefficients of all these compounds were calculated from High Temperature X-ray diffraction (HT-XRD) data whereas the effect of temperature on the bond lengths was investigated by Rietveld refinement of HT-XRD patterns. The specific heat capacities of the compounds were obtained from DSC as well as from the high temperature Calvet calorimetry and it was found that obtained experimental results are inter-consistent. Structural stability against electron beam and gamma ray irradiation were investigated by XRD, Raman and IR measurements.

Genetic variability and diversity analyses in Electron Beam and Gamma Ray induced mutants for yield attributing traits in Urdbean [Vigna mungo (L.)

An investigation was carried out in Electron Beam and Gamma Ray induced thirty eight Urdbean mutants with two checks to explore the genetic variability and diversity. Based on the overall performance of yield attributing traits, mutants viz., ACM-014-021, ACM-015-015, ACM-015-011, ACM-015-025, ACM-015-026 and ACM-014-007 were found to be superior and could be used in breeding programme for advancing yield coupled with batter quality. High phenotypic and genotypic coefficients of variation were recorded towards single plant yield and peduncle length. High heritability along with high genetic advance was noticed for base length, peduncle length, clusters count per plant, pods count per plant and seed yield per plant. The experiment on correlation showed that seed yield per plant recorded high positive correlation with pods count per plant, pod length, clusters count per plant and seeds per pod. Genetic diversity analysis resulted in grouping of forty genotypes viz., 38 mutants and two varieties into two clusters. Cluster I had 16 mutant lines along with VBN (Bg) 4 variety and cluster II had 22 mutant lines along with MDU1 variety. D2 cluster analysis based on eleven quantitative characters resulted in five groups with cluster V containing maximum of sixteen mutants along with two check varieties&nbsp;&nbsp; followed by clusters I with 15 mutants, cluster IV with three mutants and cluster II and III with two mutants each. The cluster per se performance revealed that cluster III&nbsp; recorded the maximum mean values for branches per plant, clusters, pod numbers per plant, quantity of seeds per pod, test weight,&nbsp; seed yield per plant and plant height. Cluster IV had the highest mean value for base length and pod length. Cluster I had the maximum peduncle length. As the mutants falling between cluster IV and V exhibited maximum inter-cluster distance, selection of parents could be made from these clusters for future breeding program. Keywords: Variability, Association analysis, Diversity, Urdbean.

ПЕРСПЕКТИВЫ РАЗВИТИЯ ПРОТОННОЙ ТЕРАПИИ В РОССИИ

It is generally accepted that a proton therapy is one of the most effective method of external beam radiotherapy. Proton therapy has the highest conformal factor even compared with the most modern facilities for radiotherapy which use electron beam or gamma rays. Accuracy of combination of the 90–95 % isodose surface with PTV is better and dose gradients outside PTV is steeper, also integral dose of radiation from proton therapy for a healthy tissue is less than two times that for gamma irradiation. We can clearly see it comparing a HDV of treatment plan for gamma irradiation and proton therapy for the same clinical cases. In last years a lifespan of patient after radiotherapy treatment is a quit extended, so a question for quality of life for them is more significant. Decreasing of integral dose for a healthy tissue reduces a chance of negative effects from radiotherapy that would mostly appear after a lot years after treatment, so named late side effects. Quality of life is even more important in the case of pediatric oncology, when we not only expect a long healthy life for them, but also have aim to exclude side effects from their development. There was a long term clinical investigation in 1954–1990 years in ten experimental centers (among them clinical data: 50% in USA, 30% in USSR/Russia) that had confirmed the described advantages of proton therapy. These clinical results formed a foundation of quick development proton therapy clinical centers in developed countries in 1990s. These centers are based on oncology and multidisciplinary hospitals and treat 1000 and more patients per year. There are 96 working and 38 constructing PTCs in the world for today. Although we have a lot of experience in proton therapy in Russia, we didn’t take part in this new stage. In fact a patient treatment was over in all of three experimental PTCs (Moscow, Dubna, St. Petersburg) up to 2014. Thus we have a delay in a development of proton therapy for 30 years from a world level. Government of the Russian Federation Decree № 287 of 16th March 2020 establishes Program, which has to overcome this delay in development. Main science executer of the Program is National Research Center «Kurchatov Institute», which has an experience, scientific potential and competence for it. The main aims, stages and objects of the Program are presented.