Gamma Radiation Source Research Articles

Experimental and theoretical study on the physico-mechanical characteristics and radiation shielding capability of hardened alumina sludge waste-cement pastes containing MnFe2O4-nanoparticles

This research investigates the impact of incorporating low-cost MnFe2O4 spinel nanoparticles (MF-NPs) at varying concentrations (0.5, 1, and 2 mass%) on the mechanical and physical properties of blended cement pastes. These pastes were produced by replacing different proportions (5, 10, and 15 mass%) of ordinary Portland cement (OPC) with activated alumina sludge waste (AAS), to promote sustainability. Also, the research examined the gamma radiation shielding effectiveness of certain hardened composites against a 137Cs gamma radiation source with an energy of 661.64 keV using a NaI (Tl) detector (Oxford Model) with 3″ × 3″, amplifier and 16 k multi-channel analyzer. The linear attenuation coefficient (LAC) of all the studded samples were calculated theoretically using a Monte Carlo code MCNP-5 code. The gamma radiation shielding properties were analyzed in depth using a Monte Carlo code MCNP-5 simulation model. The theoretical and experimental results for LAC were found to be in complete agreement. Phy-X/PSD software was applied to estimate the mass attenuation coefficient (MAC) for gamma radiation at various energies, as well as the effective atomic number (Zeff), mean free path (MFP), half-value layer (HVL), and tenth-value layer (TVL). The findings demonstrated that the addition of 0.5% MnFe2O4 nanoparticles (MF-NPs) to blended cement pastes exhibited the best physical and mechanical characteristics, as well as the most effective gamma radiation shielding.

Investigating adsorption and removal of divalent Ca2+ and Pb2+ ions from aqueous solutions by gamma-irradiation using quartz tuning fork (QTF) sensor technique

In this study, gold-coated quartz tuning forks (QTFs) sensing devices functionalized with self-assembled monolayers (SAM) of a lower-rim functionalized calix[4]arene methoxy ester were used for the detection of divalent Ca2+ and Pb2+ ions in aqueous solutions by utilizing adsorption behavior and the radiative effect. The gold-coated QTF functionalized calix[4]arene methoxy ester sensing device was tested by measuring the respective frequency shifts obtained using small (60 µL) samples of aqueous PbCl2 at two different concentrations (10−6 and 10−4 M). For 10−4 M solutions of PbCl2, results showed that the resonance frequency shift Δf = 317 Hz, from 32,867 Hz (fCalix) to 32,550 Hz (fCalix⊃Pb2+) due to the absorption of lead (Pb2+) ions (10-4 M) by calixl[4]arene methoxy ester receptor molecules on the QTF sensing layer from the aqueous solution to forming the ([Calix ⊃ Pb2+]) complex. The most significant frequency changes were observed at a concentration of 10−6 M CaCl2, where CaCl2 exhibited the biggest change of 356 Hz, from 32,893 Hz (fCalix) to 32,537 Hz (fCalix⊃Ca2+), compared to 317 Hz for PbCl2 (10−4 M). The limit of detection was 100 femtomolar (fM) for CaCl2 and 245 fM for PbCl2. After that, we irradiated the receptor molecules which was holding Pb2+ ions in the complex ([calix ⊃ Pb2+]) on the QTF sensing layer with a radiation dose ranging from 7.5 to 50 µGy of gamma rays from the Cesium-137 source for 30 min. Interestingly, it was observed that the resonance frequency shift (Δf = 54 Hz) back to 32,604 Hz from 32,550 Hz (f(Calix⊃Pb2+)), which strongly suggests that the Pb2+ ion removed from ([calix ⊃ Pb2+]) complex on the QTF sensing layer due to gamma radiation dose. To follow up on the radiation effect of the ([calix ⊃ Pb2+]) on the QTF sensing layer, we stopped the gamma radiation source and kept it for an additional 10 min to see if there was any resonance frequency. It was noticed that an additional resonance frequency shifted (Δf = 33 Hz) back to 32,637 Hz from 32,604 Hz after stopping the gamma radiation source for 10 min. We assume that the complex ([calix ⊃ Pb2+]) absorbs the gamma radiation and continues the removal of Pb2+ ions from the complex on the sensing layer. A similar phenomenon was also observed for the absorption of lead (Pb2+) ions (10-6 M) by calix[4]arene methoxy ester receptor molecules on the QTF sensing layer from the aqueous solution to forming the ([Calix ⊃ Pb2+]) complex. The resonance frequency shift Δf = 142 Hz, from 32,706 Hz (fCalix) to 32,564 Hz (fCalix⊃Pb2+) due to the absorption of lead (Pb2+) ions (10-6 M) by calix[4]arene methoxy ester receptor molecules on the QTF sensing layer from the aqueous solution to forming the ([Calix ⊃ Pb2+]) complex. Subsequent exposure to gamma radiation, with doses ranging from 7.5 to 50 µGy from a Cesium-137 source over 30 min, prompted a resonance frequency shift (Δf = 37 Hz) back to 32,606 Hz from 32,564 Hz (f(Calix⊃Pb2+)). This shift strongly suggests the removal of Pb2+ ions from the ([calix ⊃ Pb2+]) complex on the QTF sensing layer due to gamma radiation dose. X-ray photoelectron spectroscopy (XPS) analysis confirmed the chemical adsorption of Pb2+ ions onto the gold-coated QTFs functionalized calix[4]arene adsorbent sensing layer surface. Therefore, the technology underlying the calix[4]arene-functionalized sensing device holds promise for diverse industrial applications, supporting potential advancements in water pollution mitigation through the proposed adsorption and irradiation mechanism.

Utilization of radiometric data for mapping primary and secondary sources of gamma radiation and radon/thoron release potentials in Ireland.

This paper presents a novel approach to predict and map radon and thoron levels. We developed separate radon and thoron prediction maps for Ireland and introduced a system for producing high-resolution 3D radiation maps which may be used for planning purposes in residential areas, recycling and demolishing waste depots, and quarries of building and construction material. Additionally, we highlight the critical need to monitor thoron alongside radon in indoor surveys, as thoron's shorter half-life and higher energy levels may pose a greater health risk. We utilized Tellus radiometric survey data and indoor radon measurement records to investigate the spatial correlation between elevated indoor radon activity and anomalies in radioelement concentrations. We also estimated the degree of thoron interference in indoor radon surveys conducted in Ireland using CR-39 detectors. Field and laboratory surveys were performed to produce high-resolution radiation maps for four Irish quarries and estimate the radon and thoron potential of these quarries. Our initial findings suggest that thoron may be the primary health issue in some parts of Ireland, surpassing radon. For example, our map shows that the expected thoron potential in county Donegal is significantly higher than that for radon. Our radon and thoron exhalation tests on building material samples from four random quarries confirm this. We also estimate that over 20% of the elevated indoor radon activity recorded by the EPA using CR-39 detectors may be attributed to thoron-related sources. This study contributes to a better understanding of the prevalence and impact of radon and thoron in Ireland, helping to determine the main radiological health issue related to indoor air quality in the country. Thoron's impact on indoor air quality and health has been understudied in Ireland, necessitating more comprehensive studies and monitoring programs to accurately assess the prevalence and impact of both radon and thoron.

Towards accurate dose assessment for emergency industrial radiography source retrieval operations: A preliminary study of 4D Monte Carlo dose calculations

The exposure devices utilizing high-activity gamma radiation sources for industrial radiography frequently encounter issues such as stuck or disconnected sources, posing a substantial risk of radiation exposure to the workers executing emergency source retrieval operations, emphasizing the importance of accurate dose assessment. In the present study, the radiation dose to the main worker during the process of source retrieval was calculated and compared for five emergency source retrieval procedures to retrieve stuck or disconnected sources, using 4D Monte Carlo dose calculation and a mesh-type reference computational phantom. For a stuck source, the dose values of the two source retrieval procedures (i.e., repair and cut methods) were found to be relatively small, which indicates that the worker might select either method based on personal preference or situational convenience. Conversely, for a disconnected source, the dose values of the three source retrieval procedures (i.e., fishing, connect/push, and hot stick methods) were much larger and show significant differences. Notably, the fishing method was associated with the lowest dose, whereas the hot stick method resulted in significantly higher doses, differences being as large as ∼5 times. These results underscore the fishing method as a preferable option, particularly over the hot stick method.

Studies of the phase composition and ultrafine structure of the initial domestic raw materials of proppants

The results of the study of intracrystalline electric and magnetic fields in samples on 57Fe nuclei by the ultrafine method of the Mossbauer effect are considered. The source of gamma radiation was 57Co in the chromium matrix. The spectra of the samples were measured on 57Fe nuclei using the MS1104Em spectrometer in the mode of constant accelerations at room temperature for absorption. The crystal structure, phase composition, and electronic states of individual components of the proppants are given. The measurements were carried out on the d8 Advance universal complex (Bruker, Germany). The data of parameters recorded on detectors of secondary energy characteristics of X-rays corresponding to K, L, M, N and O levels of electronic transitions using computer processing of elemental compositions and their ratios in samples are analyzed. The data of X-ray studies of the composition of fly ash are presented, determining its potential application in various industries, including the production of proppants. The results of the analysis of the chemical composition of bauxite samples obtained by X-ray diffraction analysis are presented. The silicon modulus (µSi) has been determined, which is the ratio of Al2O3 to SiO2 to characterize the quality of bauxite. The main components of bauxite were Al2O3 (aluminum oxide) and SiO2 (silicon dioxide). A significant content of Fe2O3 (iron oxide) was also noted, which is 24-33 wt. % for bauxite.

Effect of fibers and boron carbide on the radiation shielding properties of limestone and magnetite aggregate concrete

Research on new composite materials in the field of radiation shielding materials requires adequate means and meticulousness in their manufacture and characterization. In this study, concretes that use elements that theoretically improve their shielding properties are developed, such as fibers and boron-rich additions. Both magnetite and limestone concrete have been manufactured, incorporating steel fibers to improve the linear attenuation coefficient and polyvinyl alcohol to increase neutron scattering cross section. The incorporation of boron carbide is intended to increase the neutron absorption cross section. 5 mixes have been manufactured that have been tested with several gamma radiation sources (570–1280 keV) and with an Am–Be neutron source (111 GBq). The experimental results have been used to validate simulations carried out with MAVRIC® and have led to the modelling of a simplified spent nuclear fuel cask. Boron carbide produces a decrease of more than 50% on the neutron dose rate in contact with the cask. Incorporating PVA fibers supposes gain in neutron attenuation capacity of up to 13%, while fibers have a negligible effect on the photon dose rate.

On-Stream Pipe Scale Inspection Using Gamma-Ray Tomography Technique: Field Experiment in Karaha Geothermal Power Plant, Indonesia

Pipe scaling is a common problem in geothermal power plants. Currently, the pipeline withinside the Karaha Telaga Bodas geothermal subject is indicated to incorporate scale because of pressure anomalies. On-stream pipe scale inspection techniques are needed to maintain the production process. This research aims to apply the gamma-ray transmission tomography technique to pipelines in geothermal fields. The gamma-ray tomography system consists of a 137Cs (2.96 GBq) gamma radiation source, a scintillation detector, mechanical parts, control parts, and data acquisition. Scanning was performed at three predetermined points: brine pipe 1, two-phase pipe, and brine pipe 2. The system scans half of the pipe circumference (180°) and divides it into 32 projections (5.625°). Each projection performs a translational scan with a resolution of 4 mm. Three cross-sectional images of the pipe were obtained, showing the inside condition. Pipe scale was observed at three scanning points with a thickness of 12 mm-48 mm. Gamma tomography can potentially be a tool for examining pipe scale thickness in geothermal fields. The use of a single detector is a limitation that needs to be improved. Apart from that, the stability of the control and mechanical parts must also be improved.

Development of heavy mineral filler based FRP composites for (low energy) radiation shielding application

The present study deals with fabricating and characterizing glass fiber reinforced epoxy composites with heavy mineral filler (magnetite particles) for potential low-energy radiation shielding applications. The composite materials were fabricated by the hand layup method. Glass/epoxy composite was used as control sample, and radiation shielding composites were manufactured by mixing 20 and 30% (by weight) magnetite particles with epoxy resin. It was revealed that the tensile properties of the magnetite-modified composites were increased, and the composites containing 30% filler exhibited maximum improvement than the control ones. Further assessment of the composite samples was performed by DMA (Dynamic Mechanical Analysis), TGA (Thermogravimetric Analysis), FTIR (Fourier-Transform Infrared) spectroscopy, water uptake (%), and SEM (Scanning Electron Microscopy) testing. The radiation shielding ability of the control and filler-modified composites was assessed by using a gamma (γ) radiation source (60Co). Then, the shielding efficiency was characterized by radiation-reduced intensity (%), LAC (Linear Attenuation Coefficient), MAC (Mass Attenuation Coefficient), HVL (Half Value Layer), TVL (Tenth Value Layer), and SVL (Sixteenth Value Layer). It was revealed that the 30% magnetite filler content composite experienced relatively good attenuation performance against γ-ray than other studied composites.

Evaluation of the capability of coumarin dye as a liquid scintillator for gamma ray detection and compton edge localization

In this work, we developed a highly sensitive liquid scintillator (LS) using Coumarin 450 (C450) dye to detect gamma ray and localize Compton edges (CEs). C450 exhibited absorption and fluorescence peaks at 350 nm and 407 nm, respectively, in toluene, at an optimized concentration (3 mM). The LS, contained in a standard glass container (1.8 cm diameter, 3.6 cm height), showed an emission peak in the blue region, matching the high quantum yield of typical PMT photocathodes. We exposed the LS to various gamma radiation sources (137Cs, 60Co, and 22Na), recording responses for different PMT voltages. Gaussian fitting of pulse height distribution spectrum allowed CE identification at the half-height for all PMT voltages. We compared theoretical and experimental results to a GEANT4-simulated detector, obtaining CE positions for radiation interactions and scintillation photon transport. The calibrated GEANT4 simulation was compared to experimental spectra to locate the Compton edges.

Nuclear radiation shielding performance of the new lead‐free TeO2–Bi2O3–ZnO–BaF2glass

AbstractThis paper studied the radiation shielding properties of new lead‐free telluride glass with different BaF2content. The 65TeO2–15Bi2O3–(20 − x)ZnO–xBaF2glass systems (wherex = 1, 3, 5, 7, 9 mol%) were tested through the X‐ray diffraction, ultraviolet–visible spectrophotometer, and differential scanning calorimetry. The glass system exhibited good thermal stability and a uniform surface without surface crystallization. The linear attenuation coefficient of the TBZBF series glass was tested using five different gamma radiation sources (241Am,133Ba,57Co,137Cs, and60Co). They were calculated to the mass attenuation coefficient, half‐value layer, mean free path, and effective atomic number through numerical simulations with XCOM software. The maximum mass attenuation coefficient for TBZBF‐9 was calculated to be 5.3577 cm2/g. Comparisons were made between this glass system and other tellurite and leaded glasses reported in the literature. The glass system exhibited superior radiation shielding capability compared to leaded tellurite glass under the same testing conditions. The gamma radiation shielding capacity increased with BaF2content in the glass system. These results show that TBZBF‐9 exhibited the best gamma radiation shielding effectiveness while maintaining glass transparency.

Characterization of a Germanium Detector by Means of Experimental Measurements and GEANT4 Monte Carlo Simulations

A HPGe detector was modelled and characterized by means of experimental measurements and Monte Carlo simulations. The simulation based on Monte Carlo GEANT4 was used to characterize the potential dead layer/inactive materials and Full Energy Peak Efficiency (FEPE). The calibration of FEPE for the HPGe detector was conducted in the γ-ray energy range from 88 keV to 1332 keV, using eight standard point sources of gamma radiation: 137Cs, 133Ba, 109Cd, 65Zn, 60Co, 57Co, 54Mn, and 22Na. The efficiency dependence curves were obtained by changing the source to detector distance from 8 cm to 12 cm. a remarkable similarity in FEPE for low energy measurements ranging from 88 keV to 122 keV was obtained between the simulation results and the experimental measurements.

Gamma-ray shielding parameters analysis for some polymers using Phy-X/PSD and WinXCom

In this paper, the characteristics of gamma-ray attenuation of various polymers like PTFE, PMMA, POM and PA-6 were measured using the Phy-X/PSD program and the XCOM program for different sources of gamma radiation like 22Na, 55Fe, 60Co, 109Cd, 131I, 133Ba, 137Cs, 152Eu, and 241Am in the energy range (5.89*10-3 - 2.51 MeV). The linear attenuation coefficient and the effective atomic number for a particular polymer were both decreased as the energy of the photons increased. PTFE (C2F4 ) has the greatest μ and Zeff, as well as the lowest HVL,TVL and MFP, thus, PTFE (C2F4) is most effective in shielding gamma rays than other polymers under study.

A INFLUENCE OF OPERATING PARAMETERS ON DECOLORATION OF INDIGO CARMINE SOLUTIONS USING GAMMA RADIATIONS

Abstract: It has been observed that the process parameters influence the extent of decoloration of synthetic dyes during gamma radiolysis in aqueous solutions. The influence of some factors viz. concentration of dye, dye solution pH, addition of H2O2 on the colour bleaching of Indigo Carmine dye in aqueous medium was studied using 60Co gamma radiation source (dose rate was 0.386 kGy/hr). The dose required for the thorough decoloration was observed to be the direct function of the dye concentration in the solution. Further, when pH of solution was increased, the extent of decoloration reduced, for all the concentrations. H2O2 addition had the accelerating effect on the overall decoloration. The addition of H2O2 was governed by the critical value which corresponds to optimum dose of H2O2 that is required for maximum decoloration.

MICROBIOLOGICAL QUALITY AND ACCEPTANCE OF GAMMA IRRADIATED FERMENTED MUSHROOM AND CABBAGE DURING STORAGE

For developing countries, safe shelf-stable foods without refrigeration would offer advantages. Gamma ray, an ionizing radiation is known to be a safe technology for treating food products in extending their shelf-life. Studies were carried out to overcome arisen problems of the safe shelf-stable food and to evaluate the suitability of irradiation in preserving local fermented mushrooms (Pekasam Cendawan) and local fermented cabbages. Generally, local fermented mushrooms can be kept in room temperature and under chilled condition only for one and three days respectively. Similarly, local fermented cabbages require chilled condition for storage to avoid the packages bloated upon displayed and storage. Fresh packed fermented products were obtained from local producers and irradiated at doses of 2.0 kGy, 5.0 kGy and 10 kGy, using 60Co gamma irradiation source at MINTec-Sinagama. The irradiated and non-irradiated samples were displayed at room temperature storage periods for 2 weeks, 1 month, 3 months and 6 months. Microbiological analysis was carried out to determine status of bacteria (Total Plate Count) and fungi counts. The results were expressed as colony forming units per gram (cfu/g). Colour changes of the products were recorded using Colorimeter (Minolta) for lightness (L), redness (a) and yellowness (b) values. Acceptability of the irradiated fermented products were determined through sensory evaluation by using 30 members (male and female) of untrained panellists. The fungal and microbial counts in both samples irradiated at 5 and 10 kGy were more lowered than samples irradiated at 2 kGy. After storage at 3 months, the fungal and microbial counts were increased in the both control samples of fermented mushrooms and cabbages but maintained low in both irradiated samples. The control samples of fermented mushrooms (not irradiated) were spoiled after displayed one day in room temperature and after chilled for 3 months. Both irradiated samples at 2 kGy and 5 kGy were more accepted in sensory evaluation especially the texture and taste and no significant changes (P<0.05) in lightness, redness, and redness of fermented cabbage samples during 3 months storage. However, fermented mushroom samples irradiated at 5 kGy become darker after 3 months storage. Irradiation reduced the bloatness in the packaged fermented cabbages by reducing the count of bacteria in the products. These results showed the ability gamma irradiation for decontamination of selected fermented food and reliable process for food storage in commercial industries.

Determination of Uniformity Value Response and Calibration Factors TLD Chips Using GAMMA Sources

The response of the Thermoluminescence Dosimeter (TLD) varies from one type of TLD to another depending on the material, thickness, holder, filter/absorber on each chip, type of radiation, energy and direction of radiation. This research was conducted to determine the uniformity value of the TLD chip response and to determine the calibration factor of the TLD chip using a gamma radiation source. The TLD response must be known so that the measurement results are accurate. TLD-100 irradiation in this study used a radiation source Cesium – 137. TLD used as many as 150 pieces with a large irradiation dose of 5 mSv. The irradiated TLD-100 response resulted in a standard deviation of 1% to 5% with each response corresponding to its standard deviation value. The results of the irradiation in this study the value of the calibration factor obtained for the standard deviation values of 1%, 2%, 3%, 4%, and 5% which ranged between 0,121 mSv/nC – 0,206 mSv/nC. With a large uniformity of variation in the range of 2,25% - 14%.

Devising an alternative technique to manufacture a radioisotope source of 60Co for irradiation device to ensure ornithological safety of aircraft flights

This paper reports an alternative technique for producing a source of hard gamma radiation with the 60Со isotope for the proposed device for radioactive irradiation of birds, which is also innovative in providing for ornithological aircraft flight safety. However, the high cost of producing a 60Со radionuclide source with activity sufficient to irradiate bird pests with a lethal or sterilizing dose poses a serious challenge. A solution to the problem of reducing the cost of a 60Со radionuclide source can be an alternative technique of its production outside the reactor. The results are characterized by the following features and distinctive peculiarities that make it possible to solve the problem under study: – an irradiation device with the radioactive isotope 60Со causes a lethal or sterilizing effect. This is much more effective in ensuring ornithological safety of aircraft flights compared to known methods of scaring away birds of prey, but is harmless to humans; – the production of 60Со radionuclide for the irradiation installation is carried out by thermal diffusion heating, which significantly reduces the cost of the source compared to the well-known methods of its production in a reactor and accelerator. The results obtained could find practical application in the field of civil aviation for ornithological flight safety, subject to compliance with national and international legislation. In addition, the proposed technique of manufacturing a 60Со radionuclide source, in addition to aviation ornithology, may find application in other sectors of industry, economics, and agriculture

Psychophysiological Assessment of Individual Personality in Two Patients with Severe Local Radiation Injuries (LRI) of Hand and Acute Radiation Sickness (ARS) I Degree (30 Years of Follow-up)

Psychophysiological examination was carried out on two patients, former border guards, who suffered on October 05, 1982 as a result of accidental contact with a source of gamma radiation (137Cs) while on duty while serving on the Iranian-Azerbaijani border in the ranks of the Soviet army. They suffered ARS of the 1st degree with extremely uneven gamma irradiation in the form of local radiation injuries of the hands of varying severity. The assessment of the aver -age dose for the whole body according to the frequency of dicentrics in cultures of peripheral blood lymphocytes in patient No. 1 and patient No. 2 is the same and is 0,26 Gy. Psychophysiological research was carried out in dynamics in 2001-2013 using the automated software and methodological complex «Expert». According to the MMPI data, both victims have a hyperthymic type of psychophysiological adaptation with varying degrees of severity. Patient No. 2 is a chronically hyperthymic personality with a significant increase in the profile on the 9th scale and with its gradual increase in dynamics, which reflects the persistence of hyperthymic personality traits and causes an overstrain of mental adaptation, with an increase in the dynamics of the tendency to explain their difficulties and problems by somatic distress (1Hs). Patient No. 1 has a hyperthymic personality type with a moderate increase in profile dynamics on the ninth scale. A personality trait is indicated by a high, growing in dynamics, indicator on the K scale, which determines behavior depending on social approval and concern for one’s social status. The appearance in dynamics (2013) of a peak on scales 1 (preoccupation with the state of health) and 4 (emotional tension in direct behavior) determines the insufficient ability to internalize the social norm, i.e. insufficient ability to perceive this norm as part of one’s own settings (a combination of profile peaks on scales 4 and 9). The presence of profile peaks on the 7th scale and the scales of the neurotic triad reflect the tendency to various options for the implementation of antisocial attitudes in a socially acceptable way, the desire to appear in a favorable light (scale L). Sufficiently high intelligence and demonstrative behavior determine good adaptation to the environment with self-confidence, high social adaptability, and resilience in overcoming difficulties.

External Bremsstrahlung Studies on Films of Lead Monoxide Filled Polycarbonate Composite

The development of high-Z (high atomic number) radiation shielding materials is vital in order to protect personnel who work with harmful gamma radiation sources. At the same time, the emission of external bremsstrahlung (EB) radiation in those shielding materials when the radiation source emits beta particles as well as gamma radiation is also of prime concern.The production of EB in films of lead monoxide (PbO) loaded polycarbonate (PC) composite at eleven different filler levels (FLs) varying, in terms of weight fraction, from 0.0 % up to 10.0 % were investigated experimentally by using beta particles from strontium-90/yttrium-90 (90Sr/90Y) radioactive source. A nonlinear relation is observed between EB intensity and target thickness. The effective atomic numbers of the prepared PbO-filled PC composite films (at different FLs) were determined via EB measurements, followed by calculations, and the values obtained were compared with the modified atomic numbers which were determined for the same composite films (at different FLs) using the Markowicz and Van Grieken equation, and it was found that they are in good agreement. Finally, the atomic number dependence of EB in these composite films (PbO-filled PC composites) has been studied. It is obtained that the intensity of EB spectra depends on the square of the atomic number of the target material.

Intense Laser Sources of Gamma Radiation and Neutrons Based on High-Current Beams of Super-Ponderomotive Electrons

Intense Laser Sources of Gamma Radiation and Neutrons Based on High-Current Beams of Super-Ponderomotive Electrons

Intense Laser Sources of Gamma Radiation and Neutrons Based on High-Current Beams of Super-Ponderomotive Electrons

Intense beams of photons and neutrons in the MeV energy range are effective tools in many areas of research, such as diagnostics of matter in extreme states, nuclear physics and materials science, as well as in medical and biophysical applications. A concept is presented for creating efficient sources of γ-radiation and neutrons, based on the generation of relativistic electrons in the direct laser acceleration mode during the interaction between a laser pulse with an intensity of 1019 W/cm2 and extended plasma with a density close to critical.