Radiation Protection Materials Research Articles

Experimental and theoretical study of organometallic radiation-protective materials adapted to radiation sources with a complex isotopic composition

The significance of optimizing the content of components of a radiation-protective material, which is determined by the isotopic composition of radioactive contamination, depending on the reactor type, operating time, and other factors is demonstrated. The results of computational and experimental investigation of the gamma-radiation attenuation capacity of homogenous radiation-protective materials with different fillers are reported.

Dependence of the Radiation-Protective Efficiency of AL–PB Multilayer Composites on Their Structure

We show that it is reasonable to develop one of the types of new high-performance radiation-protective materials, namely, “light metal + heavy metal” multilayer composites. The characteristics of the internal architecture of Al–Pb composites prepared by the successive application of vacuum and normal atmospheric rolling are presented. The difference between the radioisotropic and accelerated methods of experimental testing of the radiation-protective properties of materials are described. We analyze the results of testing of the composites and the influence of their structure on the radiation-protective characteristics of the investigated materials. It is shown that the radiation-protective efficiency of the composites of certain structure is higher than for aluminum by 30–40%. This enables us to reduce the weight of radiation-protective structures with preservation of the efficiency of protection on the level of aluminum or increase the efficiency of protection for a constant weight of the structure.

Investigation of Nanostructured Radiation-protective Composites

There were studied mechanisms of radiation dispersion using nanoparticles, which increase effective path of radiation quantum in nanocomposites, and which increase neutron- and Roentgen rays-protective properties multiplying of mitigation by the composite and optimal sizes of nanocrystals and filler nanoparticles were calculated. The performed experimental studies to define absorbing capability of the composite materials with fillers of tungsten and lead oxides nanocrystalline powders shown, that application of these filler materials for radiation-protective materials allows increase efficiency of radiation protection for 1.34-1.43 times in comparison to analogue material with coarse crystalines.

The Impact of λ/4 Type Absorber Protective Layer 's Thickness on Absorbing Properties

Abstract .Electromagnetic radiation affects normal operation of electronic devices and causes harm to human health, the use of electromagnetic radiation protective material, especially the electromagnetic wave absorption material, is an effective method for interference control and radiation protection, λ / 4 type dielectric absorber with a simple and practical nature, the protective layer should be added to ensure its durability in practice, this article discusses the gypsum board as the substrate, the thickness of conventional protective layer's material impacts on the absorbing properties. Studies show that: the position of absorption peak moves to lower frequency with increase of the protective layer's thickness by the theory and experiment, this paper puts forward the protective layer's thickness criterion's impact on the absorption characteristics, the thickness less than 0.05 cm has little effect on absorption characteristics in S band , which can simplify theoretical calculation and be convenient to select a material; when the thickness of the protective layer has a significant effect on absorption, the relationship among the parameters of absorber can be found according to theoretical simulation, thereby reducing or eliminating the impact of protective layer thickness on absorption characteristics.

Layered Metal Composites: Newest Generation of Radiation-Protective Materials

The expediency of development of one of the newest highly effective radiation-protective materials—layered composites of “light metal/heavy metal” type is substantiated. The characteristics of the internal architecture of composites of Al/Pb type made by consecutive application of vacuum and normal atmospheric rolling are adduced. The differences between the radioisotope and accelerating techniques of experimental testing of radiation-protective properties of materials are described. The results of the testing of composites and the influence of their structure on radiation-protective properties of the investigated materials are characterized. It is shown that the radiation-protective efficiency of composites certain structures may be 30% - 40% higher than the aluminum. This gives the opportunity to reduce the weight of radiation-protective structure at preservation of effectiveness of protection at aluminum level, or to increase the effectiveness of protection at constant weight of this structure.

Mixture of the Reaction Products during Hardening of the Water Glass Radiation-Protective Composites

The water glass can be used as a binder for the design of water-resistant radiation-protective building materials. In the present work the possibility of hardening of such materials by barium chloride is investigated. The chemical reactions which can take place during the structure forming and lead to the formation of barium hydrosilicates are presented. It is shown by means of X-ray phase analysis that formation of such hydrosilicates of composition BaO·SiO2·6Н2О, BaO·2SiO2·4Н2О, Ba2[SiO2(OH)2]2 and BaO·SiO2·Н2О actually occurs. The influence of the quantity of hardener to the chemical composition of the reaction products is examined. The effect of the reaction products to the water resistance of composite is studied. It is shown that water resistance can be increased in case of stochiometric quantity of barium chloride; in such case the primary product of reaction is BaO·2SiO2·4Н2О.

Metal-matrix radiation-protective composite materials based on aluminum

A method of mechanical activation providing a homogeneous distribution of reinforcing boron-bearing components and tungsten nanopowder in the matrix is recommended for making an aluminum-based radiation-protective material. Joint mechanical activation and subsequent extrusion are used to produce aluminum-based composites. The structure and the physical, mechanical and tribological characteristics of the composite materials are studied.

Evaluation of Novel Disposable, Light-Weight Radiation Protection Devices in an Interventional Radiology Setting: A Randomized Controlled Trial

Radiation exposure to interventionalists is increasing. The currently available standard radiation protection devices are heavy and do not protect the head of the operator. The aim of this study was to evaluate the effectiveness and comfort of caps and thyroid collars made of a disposable, light-weight, lead-free material (XPF) for occupational radiation protection in a clinical setting. Up to two interventional operators were randomized to wear a XPF or standard 0.5-mm lead-equivalent thyroid collars in 60 consecutive endovascular procedures requiring fluoroscopy. Simultaneously a XPF cap was worn by all operators. Radiation doses were measured using dosimeters placed outside and underneath the caps and thyroid collars. Wearing comfort was assessed at the end of each procedure on a visual analog scale (0-100 [100 = optimal]). Patient and procedure data did not differ between the XPF and standard protection groups. The cumulative radiation dose measured outside the cap was 15,700 μSv and outside the thyroid collars 21,240 μSv. Measured radiation attenuation provided by the XPF caps (n = 70), XPF thyroid collars (n = 40), and standard thyroid collars (n = 38) was 85.4% ± 25.6%, 79.7% ± 25.8% and 71.9% ± 34.2%, respectively (mean difference XPF vs standard thyroid collars, 7.8% [95% CI, -5.9% to 21.6%]; p = 0.258). The median XPF cap weight was 144 g (interquartile range, 128-170 g), and the XPF thyroid collars were 27% lighter than the standard thyroid collars (p < 0.0001). Operators rated the comfort of all devices as high (mean scores for XPF caps and XPF thyroid collars 83.4 ± 12.7 (SD) and 88.5 ± 14.6, respectively; mean scores for standard thyroid collars 89.6 ± 9.9) (p = 0.648). Light-weight disposable caps and thyroid collars made of XPF were assessed as being comfortable to wear, and they provide radiation protection similar to that of standard 0.5-mm lead-equivalent thyroid collars.

Radiation shielding materials and radiation scatter effects for interventional radiology (IR) physicians

To measure the attenuation effectiveness and minimize the weight of new non-Pb radiation shielding materials used for radiation protection by interventional radiology (IR) physicians, to compare the accuracy of the different standard measurement geometries of these materials, and to determine x-ray qualities that correspond to the scattered radiation that IR physicians typically encounter. Radiation attenuation capabilities of non-Pb materials were investigated. Typically, most studies of non-Pb materials have focused on the attenuating properties of metal powders. In this study, layers of materials incorporating non-Pb powdered compounds such as Bi(2)O(3), Gd(2)O(3), and BaSO(4) were measured individually, as bilayers, and as a Bi(2)O(3)-loaded hand cream. Attenuation measurements were performed in narrow-beam (fluorescence excluded) and broad beam (fluorescence included) geometries, demonstrating that these different geometries provided significantly different results. The Monte Carlo (MC) program EGSnrc was used to calculate the resulting spectra after attenuation by radiation shielding materials, and scattered x-ray spectra after 90° scattering of eight ASTM Standard primary x-ray beams. Surrogate x-ray qualities that corresponded to these scattered spectra were tabulated. Radiation shielding materials incorporating Bi(2)O(3) were found to provide equivalent or superior attenuation compared with commercial Pb-based and non-Pb materials across the 60-130 kVp energy range. Measurements were made for single layers of the Bi(2)O(3) compound and for bilayers where the ordering was low atomic number (Z) layer closest to x-ray source∕high Z (Bi(2)O(3)) layer farthest from the x-ray source. Narrow-beam Standard test methods which do not include the contribution from fluorescence overestimated the attenuating capabilities of Pb and non-Pb materials. Measurements of a newly developed, quick-drying, and easily removable Bi(2)O(3)-loaded hand cream demonstrated better attenuation capabilities than commercial Bi(2)O(3)-loaded gloves. Scattered radiation measurements and MC simulations illustrated that the spectra resulting from 90° scattering of primary x-ray beam qualities can be approximated by surrogate x-ray qualities which are more representative of the radiation actually encountered by IR physicians. A table of surrogate qualities of the eight ASTM F2547-06 Standard qualities was compiled. New non-Pb compound materials, particularly single layers or bilayers incorporating Bi(2)O(3), can reduce the weight of radiation protection materials while providing equivalent or better protection compared to Pb-based materials. Attenuation measurements in geometries that exclude the contribution from fluorescence substantially underestimate the quantity of transmitted radiation. A new Bi(2)O(3)-loaded hand cream demonstrated a novel and effective approach for hand protection. Standard testing protocols for radiation protection materials used by IR physicians specify a wider kVp range than is necessary. A more realistic range would acknowledge the lower kVp resulting from scatter and allow IR physicians to confidently utilize lighter-weight materials while still receiving adequate protection. Standards protocols incorporating the adjustments described in this work would maintain the safety of IR personnel and lessen the physical repercussions of long hours wearing unnecessarily heavy radiation protection garments.

Preparation and Properties of Smart Thermal Control and Radiation Protection Materials for Multi-functional Structure of Small Spacecraft

Considering the unique properties of small spacecraft, such as light weight, low power-consumption and high heat flux density, a new kind of lightweight boron carbide (B4C) radiation-protection coating material was proposed. New techniques for preparing LSMO thermal control coating and B4C radiation-protection coating were developed. The sample piece of multi-functional structure was manufactured by using the proposed materials, and a series of performance tests, such as thermal control and radiation-protection behaviors were evaluated. Test results show that: the emissivity of the multi-functional structure varies from 0.42 to 0.86 at 240 K to 353 K and the phase transition temperature is about 260 K. The electron radiation-protection ability of the multi-functional structure is 3.3 times better than that of Al material. The performance index of this multi-functional structure can meet the requirements for space application in on-board electronic equipment.

Thermoplastic constructional composite material for radiation protection

The possibility of synthesis of filled metallooligomer powders on the basis of lead ethylsiliconate is considered by a method of heterophase interaction, in siloksan chains of which chemically bound lead with a high concentration of atoms of lead is contained. Thermoplastic constructional composite materials for radiation protection on the basis of a polystyrene polymeric matrix modified by waterproof oligomer lead polyethylsiliconate are obtained. Physicomechanical and radiation-protective characteristics of the developed polymeric composites are studied.

Radiation shielding design strategies for lunar minimal functionality habitability element

This paper is based on a study conducted by Sasakawa International Center for Space Architecture (SICSA) between September 2008 and February 2009. SICSA has been awarded key roles in helping two aerospace company teams plan living and working accommodations for early lunar surface missions. SICSA has major conceptual design responsibilities on teams headed by Boeing and ILC-Dover which were separately selected out of more than 20 competing proposals for two out of three total NASA study contracts. Major study priorities were to determine minimum habitat requirements essential to keep crews alive and safe from harm during the first month-long missions, and then expand these accommodations as operations, facilities and amenities are extended. This paper discusses important points of radiation protection design options and known radiation protection materials applications with a special emphasis upon comparative mass implications for several proposed habitat configuration concepts. These comparisons are correlated with shielding surface area rather than actual mass estimates due to current data uncertainties regarding a number of issues: unresolved questions concerning how much radiation protection will be mandated, what mitigation strategies will be selected, what types and thicknesses of materials will be used, and how much of the total allowable module mass can be allocated for this purpose.

PREPARATION OF NANO-POLY(LEAD ACRYLATE) EPOXY RESIN BASED RADIATION-PROTECTION MATERIAL AND ITS PROPERTIES

A kind of radiation-protection material based on nano-poly(lead acrylate ) epoxy resin was successfully prepared via graft copolymerization route induced by γ irradiation. Epoxy resin contains ether bond,so the α-H atoms of the ortho-carbon and tert-carbon atoms are relatively active. Lead acrylate contains double bond. Under the exposure of γ-rays they can become the epoxidized free radicals and acrylic lead free radicals,which lead to graft polymerization. The product was characterizedand and analyzed with Fourier transform infrared spectroscopy ( FTIR),X-ray diffraction ( XRD),transmission electron microscopy ( TEM) and scanning electron microscopy ( SEM ). The stretching and bending capabilities were measured with a material all-purpose testing machine. Gamma energy spectrum measurement was carried out to evaluate its radiation-shielding properties. The results revealed that this composite material has a sea-island biphase structure. Poly(lead acrylate) particles were partially crystalline,and the particle size was about 5 nm. Graft polymerization of the two components occured at the surface of the poly(lead acrylate) particles and resulted in a network structure,which improved the mechanical properties of epoxyresin. The γ-ray mass absorption coefficient of this material with the value of 0. 060 cm2 /g under 1. 33 MeV was higher than that of lead,so that it was a good radiation-protection material with low density of 1. 37 g /cm3. The material may be applied to the field of aerospace radiation protection or radiation protection glass of electronic components packaging.

Bottom-up growth of fully transparent contact layers of indium tin oxide nanowires for light-emitting devices

Thin layers of indium tin oxide are widely used as transparent coatings and electrodes in solar energy cells, flat-panel displays, antireflection coatings, radiation protection and lithium-ion battery materials, because they have the characteristics of low resistivity, strong absorption at ultraviolet wavelengths, high transmission in the visible, high reflectivity in the far-infrared and strong attenuation in the microwave region. However, there is often a trade-off between electrical conductivity and transparency at visible wavelengths for indium tin oxide and other transparent conducting oxides. Here, we report the growth of layers of indium tin oxide nanowires that show optimum electronic and photonic properties and demonstrate their use as fully transparent top contacts in the visible to near-infrared region for light-emitting devices.

The synthesis of polyacrylic acid lead as radiation-protection composite materials and its radiation shielding properties

Polyacrylic acid （PAA） lead was successfully prepared as radiation-protection materials via graft copolymerization route. The product was characterized and analyzed with Fourier transform infrared spectroscopy （FT-IR） and scanning electron microscopy （SEM）. Gamma energy-spectrum measurement was carried out to evaluate its radiation-shielding properties. EGSnrc user code was also employed to theoretically simulate its above properties based on Monte Carlo method and analyze the influences of this material on the fluence and dose in the detecting area. The results revealed that this composite material has excellent radiation-shielding ability and this ability decreased with the increase of γ-ray energy. According to our theoretical simulation, in pure air, the change of fluence is discontinnous and looks like a ladder whose step width beomes narrower grdually and the dose increased slowly whith depth. When the sample was put into the air, in the air medium area, the changes of fluence and dose were no longer related with ray energy but with the sample thickness, while in the sample medium area, the changes of fluence and dose were not rectilinear and the rate of changes makes an obviously turn at the boundary between the sample and air.

Interaction of fast electrons and gamma-quanta with radiation protection ferric oxide composites

Physical processes of fast electron and gamma-radiation beam interaction with radiation protection ferric oxide composite materials are investigated together with dependences of energy (flux) accumulation and transmission coefficients on the gamma-radiation energy and thickness of a protective screen. Integral characteristics of radiation protection materials are calculated.

A novel radiation protection material: BaPbO 3/Al composite

The radiation protection materials for electronic devices in strategic nuclear weapon are demanded to have some characteristics: higher specific strength and modulus, and anti-radiation property. Therefore, a novel BaPbO 3/Al composite was fabricated by powder metallurgy for the first time. The microstructure of the composite was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The tensile test and photon shielding test were performed to determine the mechanical properties and radiation protection function of the composite, respectively. The experimental results shows that the composite has a similar density as aluminum, meanwhile, it exhibits excellent anti-radiation properties and improved tensile strength and elastic modulus compared with aluminum. Thus, it is promising for application as a novel radiation protection material.

環境に優しい「鉛を使わない放射線防護材」(&lt;特集&gt;画像診断機器と建築設備の関わり)

環境に優しい「鉛を使わない放射線防護材」(&lt;特集&gt;画像診断機器と建築設備の関わり)

Issues in deep space radiation protection

The exposures in deep space are largely from the Galactic Cosmic Rays (GCR) for which there is as yet little biological experience. Mounting evidence indicates that conventional linear energy transfer (LET) defined protection quantities (quality factors) may not be appropriate for GCR ions. The available biological data indicates that aluminum alloy structures may generate inherently unhealthy internal spacecraft environments in the thickness range for space applications. Methods for optimization of spacecraft shielding and the associated role of materials selection are discussed. One material which may prove to be an important radiation protection material is hydrogenated carbon nanofibers.

Радиационно-защитные и радиационно стойкие материалы для специальной техники

Радиационно-защитные и радиационно стойкие материалы для специальной техники