Photonic Radiation Research Articles

Thermal Energy Feedback Regulation of Human Life System Based on Photon Radiation

To solve the problem of the long execution time of the traditional thermalenergy feedback regulation mechanism of human life system, a method ofanalyzing the thermal energy feedback regulation mechanism of human lifesystem based on photonic radiation was proposed. The energy responseentropy of human living system is calculated by analyzing the change ofhuman living system’s thermal energy. The photonic counter is designedby using photonic radiation technology to extract the weak optical signal ofthermal energy of the system and output energy accumulation. The quadraticprogramming algorithm is used to solve the optimal solution of thermalenergy, and the neural network model is combined with the energy accu-mulation of photon counter to realize the thermal feedback regulation. So far,the design of energy feedback regulation mechanism of human living systemhas been completed. The experimental results show that compared withthe traditional feedback control mechanism, the designed energy feedbackcontrol mechanism based on photonic radiation has a shorter implementationtime and is suitable for practical engineering.

Assessment of new composites containing polyamide-6 and lead monoxide as shields against ionizing photonic radiation based on computational and experimental methods

This study aimed to introduce new composites, containing polyamide-6 (PA6) and lead monoxide (PbO), to protect against ionizing photon sources used for diagnostic and therapeutic purposes. Five composites, containing various weight percentages of PbO filler (0, 5, 10, 20, and 50%), were developed in this study. Initially, the numerical attenuation value was estimated using the XMuDat program by calculating the mass attenuation coefficients at different energy levels. Next, the samples were synthesized based on the melt-mixing method in a laboratory mixing extruder. Their characteristics were also determined by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Finally, experimental radiation attenuation tests were carried out. Based on the SEM results, the acceptable filler weight percentage was up to 20%. However, substantial aggregates were formed at the highest weight percentage. The results of XRD analysis showed a higher tendency for crystallization by decreasing the amorphous area while increasing the filler weight percentage. Moreover, the mass loss rate was monitored at different temperatures, revealing that the filler incorporation improved the thermal durability of the samples. The radiation results showed a good agreement between the experimental and computational data, except when aggregates formation was substantial. The experimental data revealed that when the lead weight percentage increased from 0% (crude PA6) to 50%, the half-value layer decreased from 3.13 to 0.17 cm at an energy level of 59 keV and from 7.28 to 4.97 cm at an energy level of 662 keV. Following the studied mechanism, the superiority of lead/polyamide composites can be found in the high adsorption of photon radiation at low energies (E < 0.20 MeV) and significant attenuation at medium and higher energies. Considering these promising results, the shielding properties of these composites can be further analyzed via more practical investigations.

Optical constants retrieval from a thin film at elevated temperatures using emittance

The refractive index and the extinction coefficient (optical constants) are essential in photonic design and thermal radiation utilization. These constants vary with the material phase, temperature, wavelength, and subject dimension. However, precisely retrieving these constants from a thin film is challenging at elevated temperatures and therefore temperature dependency is usually neglected. To tackle this challenge, a methodology for retrieval using emittance at different emission angles, θ, is developed here. The method contains four steps and takes advantage of emissometry. The method is firstly validated using simulation and then its feasibility is demonstrated by retrieving optical constants of a phase-change germanium-antimony-tellurium (Ge2Sb2Te5, GST) film. Emittance from samples at 100 °C, 200 °C, 300 °C, and 400 °C is measured at θ = 0°, 15°, and 30°. The spectral range of retrieval covers from 4 μm to 18 μm where thermal radiation dominates. The investigated film considers amorphous, face-centered cubic, and hexagonal close packed phases. The retrieved constants exhibit temperature and substrate independence, but they show a significant phase reliance.

Photoluminescence, radiative shielding properties of Sm3+ ions doped fluoroborosilicate glasses for visible (reddish-orange) display and radiation shielding applications

The various concentrations of trivalent samarium ions activated SiO2 +B2O3 + Na2CO3 + NaF + CaF2 (SBNC) glasses have been prepared with the conventional melt quenching method. Various physical parameters like density, refractive index, thickness, etc were evaluated/calculated for prepared glasses. The synthesized glasses were subject to analysis through FTIR, absorption, photoluminescence excitation, emission and fluorescence decay measurements. Judd-Oflet parameters (Ω2, Ω4 and Ω6) were estimated for all investigated SBNCSm glasses and calculated various radiative parameters. The fluorescence emission spectra consist of four sharp peaks centered at 564 nm (4G5/2 →6H5/2), 600 nm (4G5/2 → 6H7/2), 660 nm (4G5/2 →6H9/2), and 710 nm (4G5/2 →6H11/2). The glass doped with 0.5 mol % Sm3+ ions (SBNCSm05) has the highest emission intensity for 4G5/2 →6H7/2 transition (600 nm (orange)). The characteristic fluorescence emission parameters were calculated. The SBNCSm05 glass attains the higher values of stimulated emission cross-section (σemi = 11.23 × 10−20 cm2), the gain bandwidth (σemi x Δλeff = 16.22 × 10−25 cm3) and optical gain parameter (σemix τR = 19.85 × 10−25 cm2s). The lifetime of excited of Sm3+ ions (4G5/2) was estimated using the least square fitting method. The CIE chromaticity coordinate values of investigated glasses confirmed the emitted radiation fall in the visible reddish-orange region of the EM spectrum. Moreover, the shielding capacity of SBNCSm glasses against gamma photons and fast neutrons were extensively evaluated using Py-MLBUF online software. The results clearly shows that the different concentrations of Sm3+ ions into SBNC glasses improved both shielding and optical properties. The obtained values suggested that the SBNCSm05 and SBNCSm20 glasses can be used as a potential candidate in photonic device applications and radiation shielding applications.

Photonic and plasmonic transition radiation from graphene

We theoretically study the transition radiation in the framework of full Maxwell equations, when a swift electron crosses a monolayer graphene. Based on the Sommerfeld integration, we demonstrate in the frequency domain the spatial distribution of this free-electron radiation, which clearly shows the broadband excitation of both photons and graphene plasmons. Moreover, the radiation spectra for photons and graphene plasmons are analytically derived. We find that the excitation of photons and graphene plasmons favors different particle velocities. To be specific, a higher particle velocity gives rise to the excitation of photons with better directivity and higher intensity, while a lower particle velocity enables the efficient excitation of graphene plasmons in a broader frequency range. Our work indicates that the interaction between swift charged particles and various 2D materials or van der Waals heterostructures is promising for the design of terahertz on-chip radiation sources.

Photons detected in the active nerve by photographic technique

The nervous system is one of the most complex expressions of biological evolution. Its high performance mostly relies on the basic principle of the action potential, a sequential activation of local ionic currents along the neural fiber. The implications of this essentially electrical phenomenon subsequently emerged in a more comprehensive electromagnetic perspective of neurotransmission. Several studies focused on the possible role of photons in neural communication and provided evidence of the transfer of photons through myelinated axons. A hypothesis is that myelin sheath would behave as an optical waveguide, although the source of photons is controversial. In a previous work, we proposed a model describing how photons would arise at the node of Ranvier. In this study we experimentally detected photons in the node of Ranvier by Ag+ photoreduction measurement technique, during electrically induced nerve activity. Our results suggest that in association to the action potential a photonic radiation takes place in the node.

Maximal interaction of electromagnetic radiation with corona virions

Absorption and scattering of the impinging electromagnetic waves are the two fundamental operations describing the energy exchange of any, organic or inorganic, particle with its environment. In the case of virion cells, substantial extinction power, counting both absorbing and scattering effects, is a prerequisite for performing a variety of coupling actions against the viral particles and, thus, a highly sought-after feature. By considering realistic dispersion for the dielectric permittivity of proteins and a core-shell modeling allowing for rigorous formulation via Mie theory, we report optical extinction resonances for corona-virions at mid-infrared range that are not significantly perturbed by changes in the objects size or the background host. Our findings indicate the optimal regime for interaction of photonic radiation with viral particles and may assist towards the development of equipment for thermal damage, disintegration or neutralization of coronavirus cells.

Dowsing the ‘Vital Energy’ of the Planets and their Moons

An experimental dowsing of the planetary and lunar bodies of the solar system suggests that all planetary and lunar names evoke some degree of energetic excitation reflecting that of the bodies themselves. The highest values of pranic energy were found for Jupiter and the other large distant planets, and for moons close to their planet which are subject to gravitational forces and show volcanic activity. The Earth, Venus and Mars show similar moderate-high levels of pranic energy, but the low-moderate scores for pranic energy shown by Mercury and the Sun seem to verify that subtle energy production is incompatible with high production or high levels of conventional photonic radiation. A short discussion of the implications of these observations follows.

Effect of Nd: YAG laser irradiation to the temporomandibular joint on taste threshold

Background/purposeThe tissue absorption laser has been clinically applied to alleviate pain in various areas. It is used for pain relief from temporomandibular disease (TMD) in dentistry. Although the facial and trigeminal nerves are distributed around the temporomandibular joint, the effects of laser irradiation and absorption on the neural functions have not been directly studied. In this study, the Nd:YAG laser was applied to an area where the facial nerve passes with photonic radiation for the treatment of TMD. Materials and methodsTen volunteers including seven males and three females were selected as subjects. Nd:YAG laser was irradiated area included several internal and external standard and associated acupuncture points. The chorda tympani nerve, a branch of facial nerve is distributed to the front two thirds of the tongue and is associated with the sense of taste. We evaluated the effect of laser irradiation and absorption on the taste function by means of an electric taste meter. ResultsNo significant difference was identified in the values between before and after laser irradiation (Wilcoxon signed-rank test). ConclusionIt was confirmed that there was no effect on taste function while applying Nd:YAG laser irradiation around the TMD joint.

Identification of radionuclides in cooling circuit of Cyclone 18/9-HC

In the present work the patterns of relationship of photonic radiation dose rate from Cyclone 18/9HC water cooling system were studied at production of positron-emitting nuclides. Reaction (n, p) was shown to be the main source of activation nuclides in cyclotron cooling water at 18F production, resulting in formation of 16N (T1/2 = 7 s) from 16О. In water targets with high accumulated dose, when beam partially irradiates a target body, proton-induced reactions: 16О(p, α)11С and 18О(p, n)18F take place. Fluoride 18F–, carbonate 11СО32– and hydrocarbonate Н11СО3– anions, formed in proton-induced activation reactions, efficiently precipitate on anion-exchanging resin during water circulation resulting in circuit purification from the named radionuclides. Activation of cooling water does not occur at irradiation of gas targets. Projected annual dose for cyclotron operator from cooling water activation is less than 1 % of annual dose limit for personnel from technogeneous radioactive sources. In order to minimize operator`s accumulated doses it is recommended to decrease the duration of personnel activities at the distance less than 1 meter from heat exchanger during 18F production. At operation of water targets with absorbed dose higher than 2500 μA·h it is desirable to conduct the preventive maintenance of water cooling system not earlier than in half an hour after the end of irradiation and with mandatory dosimetry control. To decrease the activation of impurities it is essential to use only deionized water in cooling circuit. In case of its specific conductivity increase due to corrosion the coolant should be replaced promptly.

Monte Carlo simulation of some gel dosimeters' behaviour in photonic radiation field: research on attenuation coefficient

In this study, a model of MCNP based on Monte Carlo method was developed to calculate the mass attenuation coefficients of 15 gel dosimeters, namely LMD1, LMD2, PAG, nPAG, nMAG, VIPAR, PABIG, MAGAT, MAGAS, PAGAT, PRESAGE, BANG-1, BANG-2, BANG-3 and MAGIC at 10–1332.5 keV photon energies. In order to validate the model, the obtained results of simulation work were compared with data of XCOM. It was observed that the results were in high accordance with data of XCOM program. Accordingly, the model can be used in dosimetry, medicine and industry for various polymers and materials. Furthermore, on one hand, parameters of radiation transport in developing new gel dosimeters and materials can be calculated and assessed using the proposed model before clinical application and on the other hand, the data obtained by simulation can be used to analyze the behavior of gel dosimeters in photon radiation fields. In this regard, among 15 gel dosimeters studied here, LMD1 and PRESAGE showed the best and worst performance in comparison with other gel dosimeters, respectively. Other gel dosimeters had a poor performance, especially in energy range of 10–50 keV. Their relative mass attenuation coefficient difference with the value of water was less than 1.4%.

ОПТИКО-ЕЛЕКТРОННІ ТЕХНОЛОГІЇ ОЦІНЮВАННЯ ЗМІНИ ПЕРИФЕРІЙНОГО КРОВООБІГУ ПРИ ФОТОННОМУ ВПЛИВІ ДЛЯ КОМПЛЕКСНОГО ЛІКУВАННЯ ХРОНІЧНИХ УСКЛАДНЕНЬ ЦУКРОВОГО ДІАБЕТУ

The paper deals with the prospect of using the photoplethysmographic method for the evaluation of microcirculatory changes in peripheral circulation to study the processes that occur during photonic physiotherapy exposure for the complex treatment of chronic complications of diabetes. It is shown that photonic radiation helps to increase the elasticity of the walls of blood vessels, the elasticity of erythrocytes, oxygen transport function of the blood, the activity of cell membranes, the acceleration of processes of tissue regeneration, the reduction of lipid oxidation, the normalization of rheologic indices. After procedures of phototherapy in patients, the syndrome of thermoamputation disappeared, swelling of the legs decreased, as well as significantly decreased pain in the legs, numbness took place, leg cramps stopped. It is shown that photonic radiation of the Barva apparatus leads to anti-inflammatory, desensitizing, analgesic, antispasmodic, and anti-edema actions, which was confirmed in this study in the treatment of patients with complications of diabetes. To control the level of peripheral circulation, a photoplethysmographic method was used, which, compared to other known methods of blood circulation research, has certain advantages, because it allows to conduct studies in both transient and reflected light. It allows to obtain useful information about vascular activity, vascular response to specific substances, as well as to study blood circulation in isolated vessels of different caliber (veins, arteries, etc.). In addition, the photosensor does not cause compression of vessels of biological tissue, that is, does not cause impaired blood circulation. Thus, it is obvious that the most promising direction of registration of physiological parameters is the use of non-invasive methods of diagnosis, among which the wide development has received optical methods of registration and transformation of biomedical information and allows to study microcirculation in human tissues without impaired circulation in the study area, which is essential for medical practice.

Application of Particle Swarm Optimization Algorithm for Optimizing ANN Model in Recognizing Ripeness of Citrus

This paper shows findings of the application of Particle Swarm Optimization (PSO) algorithm in optimizing an Artificial Neural Network that could categorize between ripeness and unripeness stage of citrus suhuensis. The algorithm would adjust the network connections weights and adapt its values during training for best results at the output. Initially, citrus suhuensis fruit’s skin is measured using optically non-destructive method via spectrometer. The spectrometer would transmit VIS (visible spectrum) photonic light radiation to the surface (skin of citrus) of the sample. The reflected light from the sample’s surface would be received and measured by the same spectrometer in terms of reflectance percentage based on VIS range. These measured data are used to train and test the best optimized ANN model. The accuracy is based on receiver operating characteristic (ROC) performance. The result outcomes from this investigation have shown that the achieved accuracy for the optimized is 70.5% with a sensitivity and specificity of 60.1% and 80.0% respectively.

Final-state QED multipole radiation in antenna parton showers

We present a formalism for a fully coherent QED parton shower. The complete multipole structure of photonic radiation is incorporated in a single branching kernel. The regular on-shell 2 → 3 kinematic picture is kept intact by dividing the radiative phase space into sectors, allowing for a definition of the ordering variable that is similar to QCD antenna showers. A modified version of the Sudakov veto algorithm is discussed that increases performance at the cost of the introduction of weighted events. Due to the absence of a soft singularity, the formalism for photon splitting is very similar to the QCD analogon of gluon splitting. However, since no color structure is available to guide the selection of a spectator, a weighted selection procedure from all available spectators is introduced.

Dose Rate Linearity in 4H-SiC Schottky Diode-Based Detectors at Elevated Temperatures

The outstanding material properties make silicon carbide radiation hard and this ability has enabled it to be demonstrated in a range of detector structures for deployment in extreme environments, including those where the ability to tolerate high radiation dose is imperative. This includes applications in space and nuclear environments, where the ability to detect highly energetic radiation is important. In contrast, detectors used in medical treatment, such as imaging and radiotherapy, use a range of radiation dose rates and energies for both particulate and photonic radiation. Here, we report the response and dose rate linearity of detectors fabricated from silicon carbide to dose rates in the range of 0.185 mGy $\cdot$ min−1, typical of those used for medical imaging. The data show that the radiation detected current originates within the depletion region of the detector and that the response is linearly dependent on the volume of the space charge region. The realization of a vertical detector structure, coupled with the high quality of epitaxial layers, has resulted in a high dose sensitivity of the detector that is highly linear. The temperature dependence of the characteristics indicates that silicon carbide Schottky diode-based detectors offer a performance suitable for medical applications at temperatures below 100 °C without the need for external cooling.

A study on photomultiplier afterpulses in TL/OSL readers

In this work we present results of investigations of afterpulses in the photomultiplier tube (PMT) EMI 9235QA built into the Daybreak TL/OSL reader. The amplitudes of pulses and the time intervals between subsequent pulses were recorded using an ultra-fast data acquisition board and a laboratory made multichannel time/amplitude analyzer. We have recorded afterpulses following background (i.e. dark) pulses, pulses induced by single light photons and by high energy photonic radiation from a number of radioactive sources (241Am, 137Cs, 60Co, 90Sr/90Y) with different X/γ energy ranges. The measurements were performed at varying PMT temperatures. Distributions of time intervals between pulses show that there are several kinds of afterpulses, accompanying primary pulses caused by ionizing radiation, that follow with delays between 10−8–10−4 s. In comparison to pulses induced by a single photoelectron, the amplitude of afterpulses varies over a wide range from less than a single photoelectron to around 10 photoelectrons. In the investigated PMT for single light photon pulses we detected 7.5% of afterpulses and for background pulses up to 31% of afterpulses. Random series of afterpulses following primary pulses change the statistical distribution of the number of pulses recorded using a photomultiplier. If the number of primary pulses follows a Poisson distribution, then total counts number has another distribution with its variance greater than the mean, clearly showing an over-dispersion.

High energy photon reference for radiation protection: technical design of the LINAC beam and ionization chambers; and calculation of monoenergetic conversion coefficients

In this work, we present the results of the first part of a research project aimed at offering a complete response to dosimeters providers and nuclear physicists’ demands for high-energy (6 – 9 MeV) photon beams for radiation protection purposes. Classical facilities allowing the production of high-energy photonic radiation (proton accelerators, nuclear reactors) are very rare and need large investment for development and use. A novel solution is proposed, consisting in the use of a medical linear accelerator, allowing a significant decrease of all costs.Using Monte Carlo simulations (MCNP5 and PENELOPE codes), a specifically designed electron-photon conversion target allowing for obtaining a high energy photon beam (with an average energy weighted by fluence of about 6 MeV) has been built for radiation protection purposes. Due to the specific design of the target, this “realistic” radiation protection high-energy photon beam presents a uniform distribution of air kerma rate at a distance of 1 m, over a 30 × 30 cm2 surface. Two graphite cavity ionizing chambers for ionometric measurements have been built. For one of these chambers, the charge collection volume has been measured allowing for its use as a primary standard. The second ionizing chamber is used as a transfer standard; as such it has been calibrated in a 60Co beam, and in the high energy photon beam for radiation protection.The measurements with these ionizing chambers allowed for an evaluation of the air kerma rate in the LINAC based high-energy photon beam for radiation protection: the values cover a range between 36 mGy/h and 210 mGy/h, compatible with radiation protection purposes.Finally, using Monte Carlo simulations, conversion coefficients from air kerma to dose equivalent quantities have been calculated in the range between 10 keV and 22.4 MeV, for the spectral distribution of the fluence corresponding to the beam produced by the linear accelerator of the LNE-LNHB.

Calculating the quantitative characteristics of x-ray and gamma-ray attenuation by optical glasses

Based on data concerning the density of glasses, the mass fractions of the chemical elements that enter into the composition of the glasses, and their mass attenuation coefficients of photonic radiation with a quantum energy from 20 keV to 3 MeV, the linear x-ray and gamma-ray attenuation coefficients of typical optical and radiation-resistant glasses are calculated. The chemical elements in the composition of the glasses are indicated that have the maximum effect on the linear attenuation coefficient of photonic radiation by glasses of the crown and flint groups. The thicknesses of the layers of these glasses are determined that attenuate the γ radiation of the radionuclides Co60 (1.25 MeV) and Cs137 (0.661 MeV) to one-half and one-tenth.

Recrystallization and modification of the stainless-steel surface relief under photonic heat load in powerful plasma discharges

Targets made of ITER-grade 316L(N)-IG stainless steel and Russian-grade 12Cr18Ni10Ti stainless steel with a close composition were exposed at the QSPA-T plasma gun to plasma photonic radiation pulses simulating conditions of disruption mitigation in ITER. After a large number of pulses, modification of the stainless-steel surface was observed, such as the formation of a wavy structure, irregular roughness, and cracks on the target surface. X-ray and optic microscopic analyses of targets revealed changes in the orientation and dimensions of crystallites (grains) over a depth of up to 20 μm for 316L(N)-IG stainless steel after 200 pulses and up to 40 μm for 12Cr18Ni10Ti stainless steel after 50 pulses, which is significantly larger than the depth of the layer melted in one pulse (∼10 μm). In a series of 200 tests of ITER-grade 316L(N)-IG ITER stainless steel, a linear increase in the height of irregularity (roughness) with increasing number of pulses at a rate of up to ∼1 μm per pulse was observed. No alteration in the chemical composition of the stainless-steel surface in the series of tests was revealed. A model is developed that describes the formation of wavy irregularities on the melted metal surface with allowance for the nonlinear stage of instability of the melted layer with a vapor/plasma flow above it. A decisive factor in this case is the viscous flow of the melted metal from the troughs to tops of the wavy structure. The model predicts saturation of the growth of the wavy structure when its amplitude becomes comparable with its wavelength. Approaches to describing the observed stochastic relief and roughness of the stainless-steel surface formed in the series of tests are considered. The recurrence of the melting-solidification process in which mechanisms of the hill growth compete with the spreading of the material from the hills can result in the formation of a stochastic relief.

Precision method of direction-finding on the point gamma-source

A method for a precision direction-finding in-plane on the continuous point source of photonic radiation the range of angles 2p radian is offered. The method is realized on the basis of device in which three blocks of detection gamma rays on a base of tellurium cadmium detectors with absorbers, four spectrometric multichannel pulse analyzer and computer for information processing are included. Three types of absorbers are applied: asymmetric, sectoral and coaxial cylinder.