Low-energy Radiation Research Articles

Interlayer Electrons Polarization of Asymmetric Metal Nanoclusters/g-C3 N4 for Enhanced Microwave Therapy of Pneumonia.

Interlayer interactions in two dimensional (2D) materials promote catalytic performance but often depend on the transport of inter rather than intralayer electrons. In this study, it is found that asymmetric metal-nanocluster-doped 2D g-C3 N4 greatly enhances catalytic performance by inducing microwave excitation of interlayer electron delocalization, resulting in a polarization of interlaminar charge transport for microwave disinfection and pneumonia therapy. Asymmetric Fe and Cu nanocluster doping (DCN-FeCu) enables g-C3 N4 to generate interlayer electrons under microwave irradiation, leading to interlayer polarization processes and electron delocalization effects, thus enhancing the interlayer migration efficiency of electrons. It also improves impurity energy levels and leads to a decrease in work function, allowing DCN-FeCu to produce microwave carriers across the photoelectric potential barrier under low-energy microwave radiation (2.45GHz). This asymmetric doping modulation produces layer number-dependent microwave electron excitations that are verified using multi-metal doping. Therefore, structurally modulated asymmetric doping of 2D materials with interfacial spatial effects can provide efficient microwave disinfection and pneumonia therapy.

A Detailed View of Low-frequency Quasi-periodic Oscillation in the Broadband 0.2–200 keV with Insight-HXMT and NICER

We report the X-ray timing results of the black hole candidate MAXI J1820+070 during its 2018 outburst using the Hard X-ray Modulation Telescope (Insight-HXMT) and Neutron Star Interior Composition Explorer Mission (NICER) observations. Low-frequency quasi-periodic oscillations (LFQPOs) are detected in the low/hard state and the hard intermediate state, which lasted for ∼90 days. Thanks to the large effective area of Insight-HXMT at high energies and NICER at low energies, we are able to present the energy dependence of the LFQPO characteristics and phase lags from 0.2 to 200 keV, which has never been explored by previous missions. We find that the centroid frequency of the LFQPOs does not change significantly with energy, while the full width at half maximum and fractional rms show a complex evolution with energy. The LFQPO phase lags at high energies and low energies show consistent energy-dependence relations taking the ∼2 keV as reference. Our results suggest that the LFQPOs from high energy come from the LT precession of the relativistic jet, while the low-energy radiation is mainly from the perpendicular innermost regions of the accretion disk.

Dual-Energy Processing of X-ray Images of Beryl in Muscovite Obtained Using Pulsed X-ray Sources.

This paper presents the development of a method for dual-energy processing of X-ray images using pulsed X-ray sources for the contrast detection of beryl in muscovite mica in 2D X-ray and CT images. These substances have similar chemical properties and are difficult to differentiate when one is against the background of the other using methods based on X-ray absorption. In the experiments, we used three pulsed X-ray sources with different maximum voltages. We performed modeling of the emission spectra and selection of the necessary energy bands due to X-ray absorbing filters: a positive effect was shown for dual-energy image processing when the function of converting X-ray radiation into a signal using the VIVIX-V 2323D detector was taken into account. As a result, a pulsed X-ray source with the pulse voltage of 330 kV was chosen for the contrast detection of beryl, with the content of 5-7% against the background of muscovite and the thickness up to 70 mm. Using this source and the developed mathematical algorithms, it is possible to obtain a band of low-energy radiation at the level of 70-80 keV, as well as high-energy radiation in the range of 180 keV. Methods based on the X-ray absorption can become both additional and independent methods for studying and monitoring membranes; these objects range from tens of nanometers to several micrometers in size.

The Significance of Local Intraoperative Hemostasis and Laser Influence in the Prevention and Treatment of Complications During Thyroid Surgery

The article presents the results of clinical studies on the development of a method for local intraoperative hemostasis and improvement of reparative processes during operations on the thyroid gland. For clinical evaluation of the effectiveness of the proposed method, two study groups were formed for 237 patients with mixed, nodular and diffuse toxic goiter. The main group consisted of 98 patients, and the comparison group - 139. In the main group of operated patients, hemostasis was carried out according to the method developed by us, and in the comparison group, by traditional methods. Surgery included thyroidectomy, hemithyroidectomy, and subtotal thyroidectomy. In the main group of patients, for the purpose of hemostasis, Hemoben powder crystals with a size of 25-50 microns were used at the rate of 200 mg per area of 8-9 cm2, which was applied over the wound with a thin layer until a thin translucent film was formed, followed by irradiation of the wound with low-energy laser radiation (Sogdiana apparatus) with a wavelength of 0.89 microns, a frequency of 500 Hz for 2 minutes at a distance of 5 cm from the wound; then, for 5-7 days, percutaneous irradiation sessions with the same laser at a frequency of 80 Hz were performed daily in the projection of the surgical wound. The study showed that the use of the domestic hemostatic agent Hemoben provides complete hemostasis, and the addition of the technique by treating the surgical field with low-intensity laser radiation enhances the reparative properties of the drug. The proposed method for local hemostasis and improvement of reparative processes during thyroid surgery is characterized by a quick, effective and stable stop of bleeding, prevents the development of lymphohemorrhagic complications, and also reduces the frequency of early postoperative complications due to intra- and postoperative laser exposure.

The effect of pre-sowing electron radiation on the development of barley seedlings and the activity of enzymes and phytohormones

In a laboratory experiment, the effect of pre-sowing low-energy (160 keV) electron radiation at doses of 1, 3, and 5 kGy at a dose rate of 500 Gy/pulse was studied. on sowing qualities, morphometric parameters of barley seedlings of the Vladimir spring variety, their susceptibility to fungal diseases against a natural infectious background, as well as on the activity of enzymes and the concentration of phytohormones in 7-day-old seedlings. The repetition in the experiment was 3-fold, non-irradiated seeds served as control. Irradiation of seeds at a dose of 3 kGy caused a statistically significant increase in comparison with the control of laboratory germination (LV) by 6 % and seed growth force (SPC) by 10 %, and at a dose of 1 kGy, an increase in root length by 24.6 % and had no significant effect on morphometric parameters at a dose of 5 kGy. Seed treatment did not affect the green and dry weight of the seedlings and the percentage of water content in them. Irradiation completely suppressed the development of Penicillium spp. at doses of 1, 3 and 5 kGy, Fusarium spp. - at doses of 3 and 5 kGy and significantly increased the prevalence of Bipolaris sorokiniana seedlings by 2.1 times and its prevalence by 1.8 times at a dose of 5 kGy. Electron irradiation of barley seeds had no effect on the activity of enzymes and phytohormones, except for a significant increase in 7-day-old seedlings of the content of IAA at a dose of 5 kGy by 1.5 times and IBA at a dose of 1 kGy by 2.7 times compared with the control.

ОПРЕДЕЛЕНИЕ УДЕЛЬНОЙ АКТИВНОСТИ 177Lu И СОПУТСТВУЮЩИХ РАДИОНУКЛИДНЫХ ПРИМЕСЕЙ

Radioactive isotopes of rare earth elements (REE) are increasingly used in nuclear medicine for diagnostic and therapeutic purposes as they have effective nuclear physical properties. Seventeen elements of the secondary subgroup of group III of the periodic table of chemical elements of D.I. Mendeleev with atomic numbers 21, 39, 57, 58-71: scandium, yttrium, lanthanum and 14 lanthanides make up rare earth elements. Every year more and more attention is paid to the radioactive isotope of lutetium 177Lu, the most promising for use in therapeutic agents of a new generation, including for cell therapy of oncological diseases. The advantages of 177Lu are determined by its nuclear characteristics: the optimal depth of penetration into human tissues during radiotherapy of small tumors and low radiation load on healthy organs are provided due to the maximum energy of beta radiation of 496 keV, the presence of low-energy gamma radiation of 113 keV allows monitoring the treatment process, the half-life of 6.71 days makes it possible to transport drugs from 177Lu to significant distances.

Robust and Temperature‐Sensitive Hydrogels for High‐Efficiency Water Harvesting Under Low Solar Energy Radiation

Solar‐driven evaporation using hydrogels and photothermal materials is a promising freshwater harvesting technology. Clean water is generally collected through evaporation and subsequent condensation, which requires high energy input due to the inherent high vaporization enthalpy of water. Therefore, it is a great challenge to harvest fresh water efficiently under natural irradiation. Herein, a temperature‐sensitive polyacrylamide‐poly(N‐isopropylacrylamide) (A‐PNIPAm) gel is designed to pursue a high water collection rate under low energy input conditions, where the facile and reversible hydrophilic/hydrophobic transition in gels enables the quick acquisition of liquid water. A multifunctional hydrogel (ADS‐PNIPAm) is prepared using polydopamine and sodium alginate with excellent adsorption/filtration properties, which can remove pollutants and generate fresh water rapidly. Consequently, the water collection rate of the ADS‐PNIPAm hydrogel reaches up to 5.89 and 9.8 kg m−2 h−1 under 0.6 and 1 sun irradiation, respectively, which are superior to the previously reported values. Furthermore, ADS‐PNIPAm displays an excellent effect on purifying sewage, such as oils, algae, and dyes pollutants. ADS‐PNIPAm is a promising material for a rapid freshwater generation with solar irradiation only, which provides a new avenue to alleviate water source scarcity.

Design and performance study of a proportional counter for low-energy X-rays

A cylindrical proportional counter based on a noble gas was designed to accurately measure low-energy X-ray radiation. The detection capability of the proportional counter with different gases and geometries was calculated through the Monte Carlo method. The optimal filling gas and applicable pipe diameter were determined according to the results of the Monte Carlo simulation. Then, energy calibration was performed at the monoenergetic X-ray radiation facility (MXRF) based on Bragg diffraction, and the energy calibration results were verified using the radionuclides 241Am and 129I. The relative deviation of the theoretical and measured values of the energy does not exceed 1.4%, and the energy resolution of the designed proportional counter is approximately 10%. It was proved that the linearity of the channel and energy of the proportional counter can be used for energy spectrum analysis, and the proportional counter has a good radionuclide recognition capability. Finally, the detection efficiency of the designed proportional counter was simulated and verified at multiple energy points. A detection efficiency calculation model was established through MCNP5, and the detection efficiency of the proportional counter was measured at the MXRF. The results of the experiment and simulation showed that the proportional counter could reach a highest detection efficiency of 92% in the low-energy region. The average deviation between the experiment and simulation was 1.63% at 10–34 keV and 3.90% at 34–75 keV. The proportional counter can be used for measurement and application of X-rays in the low-energy region.

Material Effects on Electron-Capture Decay in Cryogenic Sensors

Several current searches for physics beyond the standard model are based on measuring the electron-capture (EC) decay of radionuclides implanted into cryogenic high-resolution sensors. The sensitivity of these experiments has already reached the level where systematic effects related to atomic state energy changes from the host material are a limiting factor. One example is a neutrino mass study based on the nuclear EC decay of ${}^{7}\mathrm{Be}$ to ${}^{7}\mathrm{Li}$ inside cryogenic $\mathrm{Ta}$-based sensors. To understand the material effects at the required level, we use density-functional theory to model the electronic structure of lithium atoms in different atomic environments of the polycrystalline $\mathrm{Ta}$ absorber film. The calculations reveal that the $\mathrm{Li}$ 1s binding energies can vary by more than 2 eV due to insertion at different lattice sites, at grain boundaries, in disordered $\mathrm{Ta}$, and in the vicinity of various impurities. However, the total range of $\mathrm{Li}$ 1s shifts does not exceed 4 eV, even for extreme amorphous disorder. Furthermore, when investigating the effects on the $\mathrm{Li}$ 2s levels, we find broadening of more than 5 eV due to hybridization with the $\mathrm{Ta}$ band structure. Material effects are shown to contribute significantly to peak broadening in $\mathrm{Ta}$-based sensors that are used to search for physics beyond the standard model in the EC decay of ${}^{7}\mathrm{Be}$, but they do not explain the full extent of observed broadening. Understanding these in-medium effects will be required for current- and future-generation experiments that observe low-energy radiation from the EC decay of implanted isotopes to evaluate potential limitations on the measurement sensitivity.

Synthesis and DFT supported spectroscopic characterization of a pyrazolone Schiff base complex of RuII-NO core

Due to the fact of fascinating properties of 4-aminoantipyrene and other pyrazolone derivatives, this work is mainly focused on the synthesis of Schiff base complex of Ru-NO core containing pyrazolone as the main ligand functionality. Several spectroscopic and spectrometric techniques in association with theoretical approach (DFT) have been applied to elucidate the structure of the complex. In addition to the characterization, parameters that decide to label the given compound as a significant nitric oxide releasing molecule (NORM) have been discussed. DFT based computational studies using LANL2DZ/B3LYP and 6-31 G(d,p)/B3LYP formalism, respectively for Ru and nonmetallic atoms of the complex have been used to deal with the NO-releasing phenomenon. From the results discussed herein it is evident that the complex can release NO at the cost of low energy radiation.

Enhanced wide energy regions gamma ray shielding property for Bi2O3-Gd2O(CO3)2∙H2O/EP composites with strong electron cloud overlap

With the complexity of the radiation environment and the increased demand for radiation protection, there is an urgent need for high-performance and wide-energy range gamma ray shielding materials. Bi2O3 has excellent gamma ray shielding properties, while Bi exhibits weak shielding performance of low-energy gamma rays in the range of 36.4–90.5 keV. In this work, a two-step hydrothermal strategy was proposed for Bi2O3-Gd2O(CO3)2∙H2O heterostructure (h-BG) to achieve effective shielding of the materials of low-energy gamma radiation. Bi2O3-Gd2O(CO3)2∙H2O/EP-30 composite has excellent shielding performance against low, medium, and high energy gamma radiation. In addition, the shielding performance of the Bi2O3-Gd2O(CO3)2∙H2O/EP-30 composites proved to be superior to some materials in the literature of 59.5 keV. Furthermore, simulations with the Phy-X/PSD program demonstrate that Gd2O(CO3)2∙H2O combined with Bi2O3 is an adequate method for achieving gamma radiation shielding in a wide energy region. The differential charge density calculations suggest that the formation of a heterogeneous interface between Bi2O3 and Gd2O(CO3)2∙H2O leads to an overlap of the interfacial electron cloud, which increases the probability of collision between the rays and the electrons. This is an essential reason for the enhanced gamma shielding property. This work could serve as a new strategy for the design of gamma radiation shielding materials.

Jet Cloud–Star Interaction as an Interpretation of Neutrino Outburst from the Blazar TXS 0506+056

A neutrino outburst between September 2014 and March 2015 was discovered from the blazar TXS 0506+056 by an investigation of 9.5 years of IceCube data, while the blazar was in a quiescent state during the outburst with a gamma-ray flux of only about one-fifth of the neutrino flux. In this work, we give a possible interpretation of the abnormal feature by proposing that the neutrino outburst originated from the interaction between a relativistic jet and a dense gas cloud formed via the tidally disrupted envelope of a red giant being blown apart by the impact of the jet. Gamma-ray photons and electron/positron pairs produced through the hadronuclear interactions, correspondingly, will induce electromagnetic cascades and then make the cloud ionized and thermalized. The EM radiation from jet cloud–star interaction is mainly contributed by the relatively low-energy relativistic protons which propagate in the diffusion regime inside the cloud due to magnetic deflections, whereas the observed high-energy neutrinos (≳100 TeV) are produced by the relatively high-energy protons which can continue to beam owing to the weak magnetic deflections, inducing a much higher flux of neutrinos than electromagnetic radiation. The observed low-energy electromagnetic radiations during the neutrino outburst period are almost the same as that in the quiescent state of the source, so it may arise mainly as the same state as the generally quiescent. As a result, due to the intrusion of a dense cloud, the neutrino outburst can be expected, and, in the meantime, the accompanying electromagnetic radiations from hadronic processes will not cause any enhancement in the blazar’s electromagnetic flux.

Performance of BDX-MINI veto systems

This paper describes the veto system of the BDX-MINI detector installed at Jefferson Lab (US). The BDX-MINI experiment is the first electron beam-dump experiment specifically designed to search for Light Dark Matter (LDM) particles in the MeV-GeV mass range. The core of the BDX-MINI detector is a lead-tungstate electromagnetic calorimeter, for a total volume of 4 dm3. The calorimeter is surrounded by a multi-layer veto aimed at rejecting cosmic background: the innermost layer of the veto is made by a passive tungsten shielding for low energy radiation, while plastic scintillators make the middle and outer layers for charged cosmic particles rejection. Being located about 20 m downstream, the dirt between the beam dump and the detector provides sufficient shielding from the beam-related background. In 2019–2020, BDX-MINI was exposed for about six months to weakly interacting particles (neutrinos and, if existing, DM) produced by a 2.176 GeV electron beam incident on the beam dump of experimental Hall-A at Jefferson Lab.

Prodrug Nanosensitizer Overcomes the Radiation Resistance of Hypoxic Tumor.

Clinical radiation therapy (RT) is often hindered by the low radiation energy absorption coefficient and the hypoxic features of tumor tissues. Among the tremendous efforts devoted to overcoming the barriers to efficient RT, the application of hypoxic radiosensitizers and cell-cycle-specific chemotherapeutics has shown great potential. However, their effectiveness is often compromised by their limited bioavailability, especially in the hypoxic region, which plays a major role in radioresistance. Herein, to simultaneously improve the delivery efficacy of both hypoxic radiosensitizer and cell-cycle-specific drug, a gambogic acid (GA) metronidazole (MN) prodrug (GM) was designed and synthesized based on GA, a naturally occurring chemotherapeutic and multiple pathway inhibitor, and MN, a typical hypoxic radiosensitizer. In combination with MN-containing block copolymers, the prodrug nanosensitizer (NS) of GM was obtained. Owing to the bioreduction of MN, the as-designed prodrug could be efficiently delivered to hypoxic cells and act on mitochondria to cause the accumulation of reactive oxygen species. The strong G2/M phase arrest caused by the prodrug NS could further sensitize treated cells to external radiation under hypoxic conditions by increasing DNA damage and delaying DNA repair. After coadministration of the NS with a well-established tissue-penetrating peptide, efficient tumor accumulation, deep tumor penetration, and highly potent chemoradiotherapy could be achieved.

Polylactic acid tungsten trioxide reinforced composites: A study of their thermal, optical, and gamma radiation attenuation performance

In the current investigation, the gamma radiation shielding abilities, structure, and thermal and optical properties of Polylactic acid PLA have been tried to be developed by introducing tungsten trioxide WO3. PLA/WO3 composites were fabricated by a solution mixing method at different weights percent (1%, 3%, 5%, and 7%). SEM indicates the good dispersion of WO3 in the PLA matrix, and the X-ray diffraction (XRD) pattern displays the existence of recognizable peaks for PLA and WO3. The thermal properties were investigated by thermo-gravimetric analysis (TGA), which enhances the thermal stability of the PLA/WO3 composites more than pure PLA. The transmittance decreases with increasing the WO3 content in the PLA matrix while the absorption and extinction coefficients α and k as well as the refractive index, rise with the increase of the WO3 content in the PLA matrix. The radiation shielding parameters have been experimentally reported. The equipment used in the experiment consisted of a NaI detector as well as a variety of radioactive point sources that released photons with energy of 80, 238, 356, 662, 1173, 1333, and 2164 keV, respectively. Examining the linear attenuation coefficient (μ), the half-value layer (T0.5), and the radiation protection effectiveness of the PLA/WO3 composites was done in order to investigate the gamma radiation shielding capabilities of the materials (RPE). Pure PLA (free WO3) was found to have the lowest μ values, and it was discovered that increasing the WO3 content led to an improvement in the photon attenuation competency of the present epoxy. The T0.5 lengths of the PLA/WO3 composites were lowered when WO3 was added. This verified that adding WO3 increases the radiation absorption capabilities of the PLA/WO3 composites. The four different energies were tested. Based on the findings, it is possible to draw the conclusion that non-toxic, naturally occurring composites that are low in cost and have a high WO3 content could play an important part in enhancing the gamma-ray shielding capabilities of PLA/WO3 composites for low-energy radiation applications, which can used as protective cover for solar cell against harm radiation.

Terrestrial-origin skyshine at sea level

Low-energy continuous gamma radiation with a maximum energy distribution at ∼70 keV reaches the Earth's surface from the upper hemisphere. In addition to components resulting from cosmic-origin low-energy gamma radiation, there is also a prominent contribution arising from gamma photons emitted by environmental radionuclides, which are backscattered by air above ground (commonly referred as “skyshine” radiation). Since both components are covering the same energy region of gamma radiation (mainly 30 keV–350 keV), it is not simple to determine the separate contributions of each radiation component to the total gamma flux. The efficient way to solve this long-standing problem is to study the backscattering of gamma radiation on the atmospheric air by Monte Carlo simulations. In this work, the simulations were performed in order to obtain air-backscattered spectra, as well as gamma photon fluxes which can be expected for specified activity concentrations of natural radionuclides (40K, 226Ra, 232Th) distributed in the ground. The simulation results were compared with experimental measurements of low-energy photon flux in the open area from the upper hemisphere. Furthermore, the influence of height above ground and distance from the shore on the skyshine intensity reduction is explored.

Charging Mechanism of Surface Flashover on Polyimide Under Electron Beam Irradiation

The surface flashover along the interface of solid dielectric and vacuum seriously restricts the improvement of the voltage level of vacuum electrical equipment. Surface charging is an important factor in the process of surface flashover, but its mechanism is still unclear. In this article, in situ surface potential measurement is used to measure the surface potential of polyimide radiated by electron beams with different energies, and the charging curves of polyimide at different temperatures are obtained. The experimental results show that the surface potential of polyimide is close to zero after the low-energy electron beam radiation. When the electron beam energy exceeds the critical value, the surface potential is approximately proportional to the electron beam energy. The critical values of different materials are different, such as 1.18 keV for polyimide and 1.86 keV for Teflon. The surface charging characteristic is related to sample thickness, secondary electron yield (SEY), conductivity, permittivity, and so on.

Energy-dependence investigation for a range of clinically used detectors from 70kV to 6MV.

Accurate measurement of out-of-field dose in radiotherapy directly impacts beam data modeling in treatment planning systems, verification of implanted electronic devices/lens/fetus dose, secondary cancer risk estimation, and organ-at-risk dose reporting. When performing out-of-field dosimetry, it is therefore imperative that the response of the detector has been well characterized. Due to the softening of the radiation beam out-of-field, many detectors will exhibit energy dependence. This study investigated the energy dependence of a range of clinical available detectors over typical energies experienced out-of-field. The response of detectors to photon beams from 70kV to 6MV was measured. The relative change in response from 6MV down to 70kV highlighted the expected deviation in the response of detectors that would typically be calibrated in-field for use out-of-field. The Pinpoint detector displayed the most energy-independent response over the energy range investigated. The Micro-Lion detector was the only detector to show an under-response to all low-energy beams relative to 6MV. The diode-type detectors showed the largest energy dependence. When considering detectors for use in out-of-field dose measurements, it is important that the energy dependence is investigated over a low-energy range as out-of-field the energy spectra comprise a larger component of photons in the 50-100-keV range. This study highlights the variation in response of a range of clinically available detectors to low-energy radiation beams relative to 6MV for out-of-field dosimetry. The Pinpoint detector was the most energy-independent detector with a response close to unity over the entire energy range investigated.

Влияние терапевтического лазера синего спектра на зрительные функции и внутриглазное давление в норме и при субклиническом увеите

Purpose. To study the frequency of occurrence of sluggish inflammation (BB) according to scanning laser ophthalmoscopy (SLO), identifying markers of BB using, incl., SLO; to investigate the effect of laser radiation (488 nm) blue diagnostic laser in scanning mode in healthy individuals, and low-energy blue therapeutic laser (450 nm) – on visual functions and the level of intraocular pressure (IOP) in patients with BB and primary open-angle glaucoma (POAG). Material and methods. The study included 394 patients who underwent laser scanning ophthalmoscopy; a group of 11 patients with a combination of sluggish uveitis and primary open-angle glaucoma (a 450 nm blue therapeutic laser session was performed) and 5 healthy individuals underwent standard ophthalmological examination, laser scanning ophthalmoscopy, computer threshold perimetry, autorefractometry and non-contact tonometry. Results. The presence of sluggish inflammation was determined according to the SLO data in 43 % of patients in this sample. Markers of sluggish inflammation were determined according to the data of the SLO and computer perimetry. In the group of patients with BB and POAG, significant improvements were noted: MD improvement by 67.7 %, IOP reduction by 10 %. With the selected modes of exposure to diagnostic blue laser (488 nm) in healthy individuals and low-intensity blue laser (450 nm) in the group of patients with BB and POAG, there was no negative effect on the field of vision (with «white on white» perimetry and blue-yellow perimetry) and IOP. Conclusions. 1. Scanning laser ophthalmoscopy can be effectively used for screening of sluggish inflammation with sufficient transparency of optical media. The frequency of occurrence of explosives in our sample was 43 %. 2. With the selected modes of exposure to blue-spectrum lasers, there was no negative effect on the field of vision and IOP both in the group of patients with a combination of BB and POAG (therapeutic laser 450 nm) and in the group of healthy individuals (diagnostic laser 488 nm) with a single exposure. 3. It is advisable to study the course effects of low-energy laser radiation in the blue spectrum in groups with explosives to determine the optimal accumulated dose.

The PADME charged particle spectrometer

The PADME experiment aims at searching signals of a dark photon A′. This is done evaluating the final state missing mass of the process e + e − → A′γ by knowing the beam energy and measuring the four-momentum of the ordinary recoil photon. The determination of this quantity, and the capability to reject the background, are the key points for the success of the experiment.Three charged particle detectors are employed to detect the positrons that have radiated a high energy photon in the target (PVeto), electrons from the beam interactions in the target or from particles which decay to final states with electrons (EVeto), and the positrons with a relatively low energy radiation in the target (HEPVeto). All three detectors are made of plastics scintillator bars placed inside the vacuum vessel of the PADME setup. PADME Commissioning took place in 2018-2019 with the beam of the Linac of the local Beam Test Facility (BTF) and results and performance of the veto stations will be presented.