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Rhinogenic intracranial complications, such as brain abscess and thrombosis of the veins and sinuses of the brain, are still a formidable, life-threatening pathology, often resulting in death, despite the widespread development of antibiotic therapy and adherence of patients to the treatment. Often the cause of the development of intracranial complications is the exacerbation of a chronic inflammatory process in the paranasal sinuses, while acute ENT pathology of the sinuses leads to the development of rhinogenic complications only in a small percentage of cases. Unfortunately, the high development of radiation and laboratory diagnostics does not always allow diagnosing these conditions in time and providing adequate surgical care. In childhood and adolescence, it is important to perform a timely complete and at the same time minimally invasive, non-disabling, surgical intervention. An analysis of foreign literature in recent years shows that neurosurgical operations in various volumes (from trepanopuncture of the brain to craniotomy) occur in the vast majority of cases of treatment of rhinogenic intracranial complications. The article presents two clinical cases of patients with intracranial complications successfully treated in the Department of Otorhinolaryngology of St. Petersburg State Pediatric Medical University without a highly traumatic neurosurgical operation. The combination of endonasal endoscopic surgery and massive adequate conservative therapy (antibiotic therapy in combination with the use of anticoagulants for sinus thrombosis) allows the patient to recover without resorting to neurosurgical intervention.

The structure of gamma spectrometry systems for decommissioning nuclear facilities is considered. Physicotechnical characteristics of a xenon gamma spectrometer being a main device for measuring gamma spectra of analyzed objects and determining their activity are presented. The practicability of xenon gamma spectrometers in decommissioning nuclear facilities is shown. The data obtained using the gamma spectrometry system is transmitted over internet to a remote computer to process experimental data in real time.

The results obtained by measuring the efficiency of detection of charged particles (atmospheric muons) for a prototype of a polyvinyltoluene-based scintillation detector being created for the anticoincidence system of the Signal experiment on board the Interhelioprobe spacecraft are presented. These measurements rely on determining the ratio of the numbers of triple and double coincidences of pulses that arise as atmospheric muons traverse the detector system.

Microsatellites have recently opened windows of frequent and low cost missions for planetary exploration. The performance of gamma-ray and neutron spectrometers on future microsatellite missions is simulated to assess the possibility of observation of hydrogen and major elements, given their concentration on the observation target. The measured elemental abundance will provide important geological constraints, and some of them may serve as space resources. Four different types of target bodies with various hydrogen concentrations in the range of 0 - 20,000 ppm are assumed as target compositions; Earth’s core, C-type, S-type and Martian meteorites. Gamma-ray and neutron emission rates show unique footprints that are related to the different elemental compositions. The starting point is the solid angle subtended between observation target and spectrometers that allow estimating the gamma-ray and neutron count rates emitted by the celestial bodies. In this work, three types of gamma-ray detectors; high-purity germanium (HPGe), CeBr3 and LaBr3(Ce), a neutron spectrometer combining a lithium glass scintillator with a boron loaded plastic scintillator and a dual mode spectrometer Cs2LiYCl6(Ce) (CLYC) are simulated, focusing on their observation backgrounds as a model case for microsatellite based measurements. The background count level of both gamma-ray (except for the LaBr3 detector) and neutron count rates was negligible under these particular conditions. The gamma-ray detectors were compared by the figure of merit, which was determined by their efficiency and energy resolution. It was found that each detector has unique advantages. The HPGe detector has the highest figure of merit due to its excellent energy resolution, whereas the CLYC detector is low in weight and power consumption due to its dual sensitivity to gamma-ray and neutron. The CeBr3 detector is an intermediate choice. The neutron count rates are calculated separately in three energy ranges, i.e. , thermal ( 500 keV), as a function of the hydrogen concentration in the 0 - 20,000 ppm range. The thermal and epithermal neutron count rates are found to decrease with hydrogen concentration, while the fast neutron count rate increases with the target average atomic mass. The optimal detector should be decided by the mission restraints on mass, power consumption, and heat thermal design.

The RED-100 experimental setup, which is designed to detect elastic coherent neutrino scattering off xenon nuclei, is described. One specific feature of this setup is the possibility of using it in above ground experiments. The setup is based on the RED-100 two-phase emission detector in which liquid xenon is used as a working medium for detection of rare events. The results of the technical run with the setup are presented. These are the evidence of the normal operation of all systems and the readiness of the setup for carrying out an experiment.

The intrinsic background of a LaBr3(Ce) scintillator with a diameter of 5 mm and a height of 10 mm has been studied in comparison with LYSO and CeBr3 scintillators. It is shown that due to its high energy resolution the detector based on a LaBr3(Ce) crystal exhibits the lowest background count rate in a specified amplitude range. The measured energy resolution of the detector based on a LaBr3(Ce) crystal with dimensions of O5 mm × 10 mm in combination with a silicon photomultiplier with an active area of 3 × 3 mm2 are presented. It is demonstrated that a detector array with the proposed configuration (a scintillator + a silicon photomultiplier enclosed in a common container) exhibits an energy resolution of 4% for 661.7-keV γ rays and a background count rate of ~0.39 cps in the energy range of (140 ± 3σ) keV.

International audience; The Interhelioprobe mission aims to investigate the inner heliosphere and the Sun from close distances (up to 0.3 AU) and from out of the ecliptic plane (up to 30°). In this paper we present the relevance of the mission and its main scientific objectives, describe the scientific payload, ballistic scenario and orbits of the spacecraft. Possibilities of scientific cooperation with other solar and heliospheric space missions are also mentioned.

The description of gamma-spectrometric apparatus “Nuclide” intended for the detection and identification of elements of radioactive space debris is presented. This device is planned to be installed on the “Universat-SOCRAT” spacecraft. The results of estimations of the sensitivity of this equipment depending on the distance to the objects under study are presented.

The operational orbit of the “Interhelio-Probe” spacecraft is described. The main objectives and missions of the Signal experiment are formulated. The Signal scientific equipment incorporated in this spacecraft is described. Its basic physico-technical characteristics are listed. Operation modes of this equipment onboard the spacecraft are considered.

A xenon gamma spectrometer (XGS) with a sensitive volume of 6 liters is described. Physico-technical characteristics of the gamma spectrometer, determined using radioactive sources of the set of standard spectrometric gamma sources, are presented. Gamma spectra of radioactive waste in a 3.4-m3 container for solid radioactive waste are measured, and isotope activities are determined. The XGS is simulated by the Monte Carlo method using the GEANT4 package. The activities are determined by a combined method with an analysis of experimental spectra and simulated data. It is shown that the XGS has good metrological capabilities for characterizing radioactive waste, including nuclide identification and their activity estimation.

The thermal stabilization system for the RED-100 liquid-xenon two-phase emission detector has been designed and tested. The RED-100 detector is developed by the Russian Emission Detectors (RED) collaboration for the experiment aimed at detecting the effect of coherent neutrino scattering from xenon nuclei. The system is based on thermosyphons (closed two-phase tubular heat pipes) that are filled with nitrogen and use free-boiling liquid nitrogen pool as a cooling machine. The system is capable of condensing 180-kg liquid xenon sample for 24 h and maintaining the temperature of a titanium cryostat in the range of 160–190 K with a precision about 0.1 K.

Protection of scientific equipment aboard spacecrafts against both natural and artificial constant magnetic fields is an urgent problem. Multilayer film electromagnetic shields produced by electrodeposition showed high shielding efficiency during laboratory tests. To test their application prospects under conditions of real space flights, a “Nanomag” scintillation telescope was developed and fabricated. Laboratory tests which demonstrated its operability at magnetic field induction to 4 mT are presented in this paper.

Electrodeposited multilayer-film electromagnetic shields are very promising for protecting various devices due to high shielding efficiency and the possibility of depositing on complex-shaped objects. In this communication, we present the results of measurements of the shielding efficiency of such shields. The shields represent alternating layers of materials with high magnetic permeability (Ni-Fe) and high conductivity (Cu). The maximum number of double layers is 45. It is shown that the shielding efficiency in the weak magnetic fields (0.1–0.2 mT) is 8–10; at higher magnetic field strengths (1.5–2.5 mT), it reaches 80–100. It is shown that the shielding factor increases with the number of layers in the shield at the same thickness of a soft magnetic material. A permalloy shield at the same amount of a soft magnetic material has an efficiency lower by a factor of 3–15 depending on the magnetic field strength.

The heat transfer characteristics of a two-phase closed tubular cryogenic thermosyphon filled with nitrogen fluid have been investigated. The thermosyphon consists of a 1.1 cm inside diameter, 5 m long copper tube coated with a few layers of the high-vacuum superinsulation and enclosed into a vacuum jacket. A free-boiling liquid nitrogen pool has been used as a cooling machine. The system is compact, free from mechanical vibrations, and can provide thermal stabilization of remotely located devices in the temperature range of 80–120 K with the heat transfer limit up to 100 W.

Experiment SIGNAL is planned to take place on board the spacecraft (SC) INTERHELIOPROBE. A xenon gamma-ray spectrometer is to be used in the experiment. The gamma-ray spectrometer in question has been chosen because of its characteristics permitting detailed probing of solar gamma-radiation under rough experimental conditions. The equipment is able to provide: high energy resolution (5-6times better than that of scintillation detectors), goodperformance at high temperatures, steady operation at significant vibroacoustic load, and high radiation resistance of working substance. The aforesaid properties of the xenon gamma-ray spectrometer meet goals and objectives of the experiment SIGNAL.

The results of the calculation of the detection efficiency of gamma-rays for the xenon gamma spectrometer (XGS) obtained using the GEANT4 Monte Carlo simulation are presented. The gamma spectra of the set of basic standard gamma-sources (OSGI) are analyzed for a real detector, and the calculated and actual detection efficiencies are compared. The XGS spectra are analyzed to determine the minimum concentration of the 152Eu radio nuclide in the 137Cs and 60Co mixture. It is shown that the xenon gamma spectrometer is capable of detecting the isotope at concentrations above 40% in the mixture.

The possibility of designing a prototype of the scintillation transition radiation detector (Sci-TRD) based on a thin (∼200 μm) inorganic scintillator has been investigated. Vacuum and silicon photomultipliers have been used in the measurements with inorganic scintillator samples based on LuBO3:Ce and wavelength shifting fibers. The light collection coefficient has been measured for scintillator prototypes under exposure to X rays, and the quantity of photoelectrons has been experimentally determined by irradiating the Sci-TRD working substance with a 241Am X ray source. The electron-hadron rejection ratio of the proposed Sci-TRD is expected to be ∼30.

Xenon gamma-ray spectrometer for monitoring of 222Rn concentration by means of measurement of its daughter nuclei gamma-ray emission intensity and the main characteristics of this device are presented. Time variations of radon concentration can be interpreted as possible precursors of the Earth’s seismic activity, such as an earthquake, several days prior to these events. The results of the first experiments that were carried out in the Caucasus region of Russia show the possibility of using the described xenon gamma-ray spectrometer for this task.

A gamma-ray spectrometer for radioactive waste sorting is presented. The equipment is based on a new “thin-walled” xenon gamma-ray detector with sensitive volume of 4 liters and a digital electronics unit. Use of the thin wall (0.5 mm of stainless steel covered with fiberglass) provides lower absorption of gamma-rays by the detector’s walls and expansion of the energy range of radiation being registered. The digital electronics unit makes it possible to use the equipment in unfavorable field conditions such as high levels of acoustic influence.

A γ-ray detector based on pressurized xenon is described, and the characteristics of the processing of the spectrum of the detector are examined. It is shown that the SpectraLine computer program, where these characteristics are taken into account, makes it possible to process successfully the spectra measured with a pressurized-xenon detector, which greatly expands the possibilities of instruments of this class for performing spectrometric measurements. The possibilities of using pressurized-xenon detectors to solve complex problems of gamma-spectrometric analysis using the GammaLab program system are analyzed. The results obtained show that it is indeed possible, in principle, to use a pressurized-xenon detector together with the SpectraLine computer program for quantitative analysis of samples with a complex radionuclide composition, specifically, to determine the isotopic composition of plutonium.

Scintillation light, ionization yield and scintillation decay times have been measured in xenon and in its mixture with a 0.05% concentration of methane as a function of the reduced electric field (E/N)-the ratio of the electric field strength to the number density of gas-at a pressure of 21 atm. The measurements of scintillation decay times in the xenon-methane mixture have been made for the first time as a function of the reduced electric field (E/N). An ionization chamber has been constructed to simultaneously measure electrons and photons from a 239Pu source, which is placed in the center of a cathode in the chamber. The main peculiarity of the chamber is a movable cathode to measure scintillation light and ionization yield at various distances from the anode and monitor the purity of the investigated gas. It has been observed that both scintillation light and ionization yield decrease when methane is added into the xenon gas. Scintillation decay times in the xenon-methane mixture are observed to be longer than in the pure xenon when the electric field strength increases.

In the experiment SIGNAL, which is planned to take place on board spacecraft INTERHELIOPROBE, a xenon gammaray spectrometer is to be used. The gamma-ray spectrometer in question has been chosen because of its characteristics permitting detailed study of solar gamma-radiation under rough experimental conditions. The equipment is able to provide: high energy resolution (5-6-fold better than that of scintillation detectors), performance at high temperatures, steady operation under significant vibroacoustic load, and high radiation resistance of the working medium. The aforesaid properties of the xenon gamma-ray spectrometer meet goals and objectives of the experiment SIGNAL. The description of ballistics scenario and operation orbit of the INTERHELIOPROBE spacecraft (SC) are presented.

Photomultiplier tubes (PMTs) are widely used in physical experiments as well as in applied devices. PMTs are sensitive to magnetic field, so creation of effective magnetic shields for their protection is very important. In this paper, the results of measurements of shielding effectiveness of multilayer film magnetic shields on PMT-85 are presented. Shields were formed by alternating layers of a material with high magnetic permeability (Ni-Fe) and high electric conductivity—Cu. The maximum number of bilayers reached 45. It is shown that in weak magnetic fields up to 0.5 mT, the output signal amplitude from PMT-85 does not change for all used multilayer shields. In strong magnetic field of 2–4 mT, the output signal amplitude decrease with 10%–40% depending from the number of layers in the shield. The Pulse distribution of PMT-85 in magnetic field 0.2–4 mT slightly changed in the range 1.1%–1.3% for the case when the number of layers do not exceed 10 and practically did not change for a shield with 45 double layers.

The scintillation response to an α source (241Am) and the ionization yield in pure gaseous xenon and its mixtures with 0.2–2% of methane were measured at a pressure of 26 atm and different values of reduced electric field E/N. Both light and ionization yields in xenon were shown to decrease with increasing percentage of methane.

Scintillation and ionization yields in xenon gas for 5.49 MeV alpha-particles were measured in the range of pressure from 0.35 to 3.7 MPa and the electric field strength (E) over the number density of xenon atoms (N), E/N from 0 to 5×10−18 V cm2. When our data are normalized at the data point measured by Saito et al., the number of scintillation photons is 2.3×105 while the number of ionization electrons is 2.0×105 at 2.6 MPa and at 3.7×10−18 V cm2. The scintillation and ionization yields of xenon doped with 0.2% hydrogen, High-Pressure Xenon gas[H2-0.2%], at 2.6 MPa was also measured. Scintillation yield of the Xe–H2 mixture gas is 80% as high as that of pure xenon. It is found that the scintillation yield is luminous enough to generate a trigger pulse of the high-pressure xenon time projection chamber, which is expected as a promising MeV Compton gamma-ray camera.

To help understand planetary gamma-ray spectra, the energies and intensities of gamma rays produced by energetic particles interacting in thick targets were simulated experimentally and numerically. Using the accelerator at RIKEN, thick targets of iron, granite, and gabbro were exposed to 180 or 210 MeV proton beam, and characteristic gamma rays emitted from the targets were measured by Ge detectors. The experimental results were compared with the values calculated by Geant4. The relative intensities of gamma-ray lines from the iron target in the experiment were consistent with those in the calculation within the error of ∼5%. As for stone targets, strong inconsistencies were observed. Further improvement in the calculation code and cross section files, as well as experimental resemblance to space missions are indispensable for gamma-ray spectroscopy.

Hi-Cal (High-Altitude Calibration) is a balloon-borne experiment that will be launched in December, 2016 in Antarctica following ANITA-IV (Antarctic Impulsive Transient Antenna) and will generate a broad-band pulse over the frequency range expected from radiation induced by a cosmic ray shower. Here, we describe a device based on an array of silicon photomultipliers (SiPMs) for determination of the azimuthal position of Hi-Cal. The angular resolution of the device is about 3 degrees. Since at the float altitude of ~38 km the pressure will be ~0.5 mbar and temperature ~ − 20 °C, the equipment has been tested in a chamber over a range of corresponding pressures (0.5 ÷ 1000) mbar and temperatures (−40 ÷ +50) °C.

A method for 222Rn concentration monitoring by means of intensity measurement of its daughter nuclei (214Pb and 214Bi) gamma-ray emission using xenon gamma-ray spectrometer is presented. Testing and calibration results for a gamma-spectrometric complex based on xenon gamma-ray detector are described.

Software tool for gamma-ray spectra analysis was developed. Software tool has the possibilities for visualization of gamma-ray spectra, background and shadow spectrum, analysing of gamma-lines by Gaussian distribution, calculation of gamma-lines characteristics, manipulation with background and shadow spectrum.

A description of the xenon detector (XD) for gamma-ray line emission registration is presented. The detector provides high energy resolution and is able to operate under extreme environmental conditions (wide temperature range and unfavorable acoustic action). Resistance to acoustic noise as well as improvement in energy resolution has been achieved by means of real-time digital pulse processing. Another important XD feature is the ionization chamber’s thin wall with composite housing, which significantly decreases the mass of the device and expands its energy range, especially at low energies.

We describe an algorithm for radionuclide detection and identification by the γ-ray spectra recorded with a high-pressure xenon γ-ray spectrometer. The algorithm is based on the comparison of the measured spectra with the tabulated radionuclide data. The fitting criteria were formulated. The software package, implementing the algorithm and providing the execution of a complete cycle of γ-ray spectrum processing, was developed. The algorithm usability and efficiency were demonstrated by testing it with actual spectra.

The abundance of 40K isotope in natural K is about 10−4. Therefore, measurements of the intensity of the 1.46 MeV gamma line from 40K allows to estimate the concentration of KCl in various mixtures and solutions. However, during the technological procedure it is necessary to carry out the measurements at a relatively high temperature, typically at about 120°C, where traditional detectors cannot be used. A high pressure xenon gamma-detector has been developed for these kinds of measurements. The detector is a cylindrical ionization chamber with a sensitive volume of 5 l. The pressure of xenon gas inside the chamber is 40 atm. A special charge sensitive amplifier capable to operate at high temperatures up to 200°C was designed for these measurements. The detector test under real industrial conditions at “Silvinit” – a company located in the North East of European part of Russia – proved that the concentration of KCl can be measured directly during the manufacturing process with an accuracy better than 1% in the temperature between 15°C and 120°C.

Software tool "Acquisition and processing of gamma-ray spectra" for xenon gamma-ray spectrometers control was developed. It supports the multi-windows interface. Software tool has the possibilities for acquisition of gamma-ray spectra from xenon gamma-ray detector via USB or RS-485 interfaces, directly or via TCP-IP protocol, energy calibration of gamma-ray spectra, saving gamma-ray spectra on a disk.

In this article the high voltage power supply for xenon spectrometer is described. Result of time simulation for output voltage at different temperatures was shown. The experimental data is confirming results of the time simulations. The experimental data showed breadboard model provides a stability of voltage better than 1% of the generated voltage at different temperatures

Shaping and digital processing of xenon gamma-spectrometer signals were considered. Digital processing influence on the energy resolution of the spectrometric system of xenon gamma-spectrometer was shown. The analysis of contributions to the energy resolution showed that the limit of improvement of the resolution by using of digital processing is reached almost.

Xenon detector based gamma-ray spectrometer for a radioactive waste sorting complex and its characteristics are described. It has been shown that the "thin-wall" modification of the detector allows better registration of low-energy gamma rays (tens of keV). The spectrometer is capable of operation in unfavorable field conditions and can identify radionuclides of interest in less than 1 second.

Possibility of creation of a well-type gamma detector based on xenon gamma-ray spectrometer was shown. The results of modelling of xenon well-type detectors are presented.

A method for earthquake precursors search based on variations of 222Rn concentration determined via intensity measurement of 222Rn daughter nuclei gamma ray emission lines by means of xenon gamma-ray spectrometer is discussed. The equipment description as well as the first experimental data are presented.

In different materials for magnetic shields, the maximum permeability is achieved for different values of the magnetic field. This determines the choice of material. So for protection from magnetic fields strength of 10 - 150 A/m it is advisable to apply the amorphous ribbon 84KXCP. For stronger fields (more than 400 A/m) it is recommended to use MFS based on Ni20Fe80. Use of these materials allows creating an effective shield working in a wide range of magnetic field strengths.

Experimental results of thermal neutrons detection by high pressure xenon gamma- ray spectrometers are presented. The study was performed with two devices with sensitive volumes of 0.2 and 2 litters filled with compressed mixture of xenon and hydrogen without neutron-capture additives. Spectra from Pu-Be neutron source were acquired using both detectors. Count rates of the most intensive prompt neutron-capture gamma-ray lines of xenon isotopes were calculated in order to estimate thermal neutrons efficiency registration for each spectrometer.

Results of developing of a gamma-ray detector based on LaBr3(Ce) scintillation crystal for neutron capture therapy are presented. An energy resolution of the detector measured by photomultiplier tube Hamamatsu R6233-100 is showed. It was 2.93% for gamma line 662 keV from a source 137Cs. For radiative capture gamma line of isotope 10B (478 keV) and annihilation line (511 keV) the values were 3.33 and 3.24% respectively. Data analysis of gamma spectra for an estimation of energy resolution threshold required for visual identification gamma lines 478 and 511 keV was made.

The principal of design and main characteristics of High Pres- sure Xenon (HPXe) gamma-ray detectors for energy range 0.1-5 MeV are described. High energy resolution of HPXe gamma-ray spectrometers (1.5% at 1 MeV) and availability to manufacture these detectors with dif- ferent sensitive volumes (0.2-10 litres) allow to apply them as for station- ary control portals as for portable inspection detectors. In both cases it is possible not only to register presence of radioactive or fissile materials but also to identify the type of these materials. Numerical tests of HPXe spec- trometers and its application to different tasks have demonstrated their per- spectives as an effective instrument to prevent acts of nuclear/radiological terrorism.

A description of the xenon detector (XD) for ecological applications is presented. The detector provides high energy resolution and is able to operate under extreme environmental conditions (wide temperature range and unfavorable acoustic action). Resistance to acoustic noise as well as improvement in energy resolution has been achieved by means of real-time digital pulse processing. Another important XD feature is the ionization chamber’s thin wall with composite housing, which significantly decreases the mass of the device and expands its energy range, especially at low energies.

A measurement data processing method, that will allow increasing detecting sensitivity of XeGRD to gammaradioactive sources, is considered. Description of a multifunctional portal monitor provided with a xenon gamma-ray detector (XeGRD) for detection and identification of radioactive and fissile materials is presented. Analysis of calibration and test results of the XeGRD included in the real portal monitor is presented. It is shown that the xenon gamma-ray spectrometer can be successfully used in portal monitors for detecting as well as for identification of various radio-nuclides.