Diode-pumped solid-state lasers are attractive for a variety of practical applications in many fields of human activity due to their high efficiency, compactness, and long durability. For applications in remote sensing lasers emitting in the spectral range of about 2 microns are required. Materials doped with trivalent thulium ions are promising active media emitting in this spectral range. Potassium rare-earth tungstates are attractive materials among Tm-doped crystals due to their suitable characteristics, such as high values of absorption and stimulated emission cross sections, incignificant concentration quenching of luminescence, well-proven technology of the high quality crystals growth. The purpose of this paper was to compare lasing properties of lasers based on potassium lutetium and potassium yttrium tungstate crystals doped with thulium ions in continuous-wave regime. Experiments were carried out with a diode pumping in microchip cavity configuration. The maximum power of laser radiation at 1947 nm of 1010 mW was obtained with Tm:KY(WO₄)₂ crystal with the slope efficiency with respect to the absorbed pump power of 51 %. When Tm:KLu(WO₄)₂ crystal was utilized an output power of 910 mW at 1968 nm wavelength with the slope efficiency of 38 % was obtained. With Tm:KLu(WO₄)₂ laser a tuning range over 160 nm range was realized with a prism inserted into the laser cavity. 

Recent research and development show promising use of high-performance solid-state receivers of the electromagnetic radiation. These receivers are based on the low-barrier Schottky diodes. The approach to the design of the receivers on the basis of delta-doped low-barrier Schottky diodes with beam leads without bias is especially actively developing because for uncooled receivers of the microwave radiation these diodes have virtually no competition. The purpose of this work is to improve the main parameters and characteristics that determine the practical relevance of the receivers of mid-infrared electromagnetic radiation at the operating room temperature by modifying the electrodes configuration of the diode and optimizing the distance between them. Proposed original design solution of the integrated receiver of mid-infrared radiation on the basis of the low-barrier Schottky diodes with beam leads allows to effectively adjust its main parameters and characteristics. Simulation of the electromagnetic characteristics of the proposed receiver by using the software package HFSS with the basic algorithm of a finite element method which implemented to calculate the behavior of electromagnetic fields on an arbitrary geometry with a predetermined material properties have shown that when the inner parts of the electrodes of the low-barrier Schottky diode is performed in the concentric elliptical convex-concave shape, it can be reduce the reflection losses to -57.75 dB and the standing wave ratio to 1.003 while increasing the directivity up to 23 at a wavelength of 6.09 μm. At this time, the rounded radii of the inner parts of the anode and cathode electrodes are equal 212 nm and 318 nm respectively and the gap setting between them is 106 nm. These parameters will improve the efficiency of the developed infrared optical-promising and electronic equipment for various purposes intended for work in the mid-infrared wavelength range. 

Nowadays the technique of analog contact potential difference probes well developed. Due to the influence of various parasitic factors, analog probes has substantial errors. The integration time for automatic CPD compensation should be at least several seconds to achieve high accuracy measurements. The speed and the accuracy are essential, for example, for Scanning Kelvin Probes. The purpose of this paper is to develop a digital contact potential difference probe, with a higher accuracy and speed of measurements as compared to analog probe. The digital probe made on base of 32-bit microprocessor with a Cortex M4 core. Measuring cycle consists of at least two successive determinations of the output signal amplitude at different compensation voltage generated by the microcontroller. It allows synchronizing of the generated oscillations and reading of the measuring signals. Data arrays processed in real time of the Digital Signal Processing by microprocessor. In this case is possible computation of the root mean square value or determination of the desired spectral line of the signal after fast Fourier transformation. Both methods permit eliminate of random noise and spurious harmonics. The method provides the digital contact potential difference probe operation in large signal mode and with a large signal/noise ratio. This eliminates the error associated with the zero signal finding. Also the integration time for automatic CPD compensation of the measured value is not necessary, which significantly reduces the measurement time and eliminates errors of compensation and DAC. In addition, the microcontroller could control the movement of the probe during scanning and transfer data to the host computer on interface USB, etc.

Research in the field of development of natural environments imitators that used for thermal cloaking of military machinery always connected with high material costs due to big sizes of cloaking objects. In this way we decided to create laboratory stand and methodic for obtaining data about temperature surface of fragments of natural environments and its imitators affected by the electromagnetic radiation of the optical wavelength range. We proposed to use a thermal imaging camera instead of the traditionally used spectrophotometric equipment for obtaining spectral characteristics of the objects under study affected by the optical radiation. This method allows us to evaluate the surface temperature of the object at different angles of lighting and viewing. Obtained data allows us to estimate the degree to which the imitator corresponds to a natural environment by the temperature and it’s dynamic of change.The construction of the stand allows to select angles of source of radiation and thermal detector in range 25–75 degrees from normal to the surface of object under study. The source of radiation consists of halogen lamps of MR16 type. The number of selected lamps and its power were chosen taking into account of imitation of intensity of sun radiation.The thermal camera MobIR M4 was used as infrared detecting unit in the range of 8–12 μm. This device has a matrix with a resolution of 160 × 120 pixels and its optical field of view, both vertically and horizontally is 25 to 19 degrees. Special remotely controlled device was created to automate the process of obtaining thermal images. Proposed methodic of measuring surface temperature of objects under study consists in obtaining thermal images at equal time intervals, their analysis using special software and plotting graphs. Thus we can use the developed laboratory stand and the methodic not only for temperature surface evaluation of fragments of natural environments but for its imitators. 

Most of the load experiencing parts operate in a complex state of stress (СSS). The article describes the device layout diagram for modeling a СSS in a ferromagnetic material and the development of monitoring methods. The principle of operation of the device is based on the joint action at a sample of longitudinal extension and lateral bending. The article describes the methods of creating a СSS and materials research using the method of the Barkhausen effect in static and dynamic loading conditions. The article presents the functioning of the algorithm and device operating principle. The article also shows the diagram for modeling a СSS in a steel sample. In this work, are the construction and operation of the device described in detail. This device differs from simple industrial test equipment by small weight, size and cost. The paper presents experimental examples of the influence of the simple forms of the state of stress (longitudinal stretching or lateral bending) and a CSS on the intensity of the magnetic noise in two samples of structural steel. The study established that the total value of the magnetic noise in complex stress state of the sample caused by the forces of simultaneously stretching and bending load, is approximately equal to the algebraic sum of magnetic noise values for each simple type of stress. The linearity of the intensity of the magnetic noise versus axial tensile stress is observed in a range of 0 to ≈ +300 MPa, flexural tensile stresses – of 0 to ≈ +500 MPa, the total stresses – to ≈ 100–110 MPa. The obtained results confirmed the efficiency and effectiveness of the device. The article shows that the magnetic noise is affected not only by the magnitude of the tensile stress of the axial force or tensile stresses in bending or full stresses, but also by the steel grade, the physical and mechanical properties of the material under test. The sensitivity of the magnetic noise to the combined action of the two types of state of stress was higher than for any separate type. The results may be useful in the evaluation of a CSS in ferromagnetic products and the various elements of steel structures. The paper presents the main technical characteristics of the device (weight 18 kg, dimensions 600 × 200 × 170 mm).

Today submicron silicon-on-insulator (SOI) MOSFET structures are widely used in different electronic components and also can be used as sensing elements in some applications. The development of devices based on the structures with specified characteristics is impossible without computer simulation of their electric properties. The latter is not a trivial task since many complicated physical processes and effects must be taken into account. In current study ensemble Monte Carlo simulation of electron and hole transport in deep submicron n-channel SOI MOSFET with 100 nm channel length is performed. The aim of the study is investigation of the influence of interband impact ionization process on the device characteristics and determination of the transistor operation modes when impact ionization process starts to make an appreciable influence on the device functioning. Determination of the modes is very important for adequate and accurate modeling of different devices on the basis of SOI MOSFET structures. Main focus thereby is maid on the comparison of the use of two models of impact ionization process treatment with respect to their influence on the transistor current-voltage characteristics. The first model is based on the frequently used Keldysh approach and the other one utilizes the results obtained via numerical calculations of silicon band structure. It is shown that the use of Keldysh impact ionization model leads to much faster growth of the drain current and provides earlier avalanche breakdown for the SOI MOSFET. It is concluded that the choice between the two considered impact ionization models may be critical for simulation of the device electric characteristics. 

Pinhole camera is one of X-ray optics devices. The pinhole camera is used for obtaining the image of synchrotron and laboratory sources, and also as a lens in a method of X-ray fluorescent microscopy. This method allows to obtain information on a spatial distribution of various chemical elements to the areas of several square centimeters with spatial resolution at the level of 50–100 μm. As a rule energy-dispersive two-dimensional CCD cameras are used for imaging. Such cameras are expensive devices and have low sensitivity for X-rays with energy of photons higher than 8 keV. Therefore it is perspective to use for X-ray fluorescent microscopy more effective CCD cameras with a scintillator layer. The purpose of this work consists in development of the device for imaging with secondary fluorescent X-rays by using pinhole as a lens and CCD camera for registration of the X-ray image. The device for obtaining the image of objects in secondary X-rays is developed. The device consists of an X-ray tube, pinhole and CCD camera. The object of research was irradiated with radiation from the X-ray tube and emits secondary X-rays. 100-microns pinhole was used for formation of the image of the object at an entrance window of the CCD camera. Images of a number of the iron springs differing in the sizes are received. It is established that the spatial resolution of the device is about 200 μm at an exposition of 60 s. It is possible to improve permission of the device by increasing in an exposition, optimization imaging conditions and reduction of the pinhole size. 

Spacecraft optoelectronic modules traditionally have aluminum alloy or titanium alloy casing which substantial weight increases fuel consumption required to put them into orbit and, consequently, total cost of the project. Carbon fiber reinforced polymer based composite constructive materials is an efficient solution that allows reducing weight and dimensions of large optoelectronic modules 1,5–3 times and the coefficient of linear thermal expansion 15–20 times if compared with metals. Optical characteristic is a crucial feature of carbon-fibre-reinforced polymer that determines composite material interaction with electromagnetic emission within the optical range. This work was intended to develop a method to evaluate Carbon fiber reinforced polymer optoelectronic modules casing effect on lens scattering by computer simulation with Zemax application software package. Degrees of scattered, reflected and absorbed radiant flux effect on imaging quality are described here. The work included experimental study in order to determine bidirectional reflectance distribution function by goniometric method for LUP-0.1 carbon fabric check test pieces of EDT-69U epoxy binder with EPOFLEX-0.4 glue layer and 5056-3.5-23-A aluminium honeycomb filler. The scattered emission was registered within a hemisphere above the check test piece surface. Optical detection direction was determined with zenith (0º < θ < 90º) and azimuth (0º < φ < 180º) angles with 10° increment. The check test piece surface was proved to scatter emission within a narrow angle range (approximately 20°) with clear directivity. Carbon fiber reinforced polymers was found to feature integrated reflectance coefficient 3 to 4 times greater than special coatings do. 

The objective of this paper is development and experimental verification special software of spectral analysis. Spectral analysis use of controlled vibrations objects. Spectral analysis of vibration based on use maximum-entropy autoregressive method of spectral analysis by the Berg algorithm. For measured signals use preliminary analysis based on regression analysis. This analysis of the signal enables to eliminate uninformative parameters such as – the noise and the trend. For preliminary analysis developed special software tools. Non-contact measurement of mechanical vibrations parameters rotating diffusely-reflecting surfaces used in circumstances where the use of contact sensors difficult or impossible for a number of reasons, including lack of access to the object, the small size of the controlled area controlled portion has a high temperature or is affected by strong electromagnetic fields. For control use offered laser measuring system. This measuring system overcomes the shortcomings interference or Doppler optical measuring systems. Such as measure the large amplitude and inharmonious vibration. On the basis of the proposed methods developed special software tools for use measuring laser system. LabVIEW using for developed special software. Experimental research of the proposed method of vibration signals processing is checked in the analysis of the diagnostic information obtained by measuring the vibration system grinding diamond wheel cold solid tungsten-containing alloy TK8. A result of work special software tools was complex spectrum obtained «purified» from non-informative parameters. Spectrum of the signal corresponding to the vibration process observed object. 

The dependence of photon energy from energy of photoelectron is base of photoemission radiation analysis. In such photoemission measurements except current of photocathode is always exist a reverse current from the collector of electrons to the photocathode in two-electrode sensors. There are various ways of reverse and uncontrolled current eliminating or reducing their influence. The constructive method is based on creating an electron-optical system of photoelectronic device, which would be a photoelectron energy analyzer. The second method – technological. However, it requires the manufacture of the photocathode and the dynode system in different vacuum chamber with subsequent connection to a single device in vacuum environment without exposure to the atmosphere. The purpose of this article is to determinate the effect of photoemission from photocathode chamber and the first dynode of photomultiplier on energy distribution of the photoelectrons from photocathode. To solve this problem authors obtained calibration curves for measuring pyrometer module ПИФ 4/2 with ФЭУ-114 as a sensor at supply voltage 1350 V and different decelerating voltages. The effect of illumination on the value of modulation coefficient on temperature k(T) and wavelength k(λ) is shown. In temperature measurements, this effect is evident in fact that at temperatures below 1400 K linear dependence ln k – T-1 is broken. Still this linear dependence is a necessary consequence of the fact that the measured temperature is color temperature. However, this calibration curve can be used to measure low temperature if the target measurements condition and calibration conditions are identical. In wavelength calibration, curve k(λ) at λ > 760 nm is two-valued, that doesn’t allow to identify monochromatic radiation by this method and bring in errors in temperature measurements. 

To ensure the radiation protection of oncology patients is needed to provide the constancy of functional characteristics of the medical linear accelerators, which affect the accuracy of dose delivery. For this purpose, their quality control procedures are realized including calibration of radiation output of the linac, so the error in determining the dose reference value during this procedure must not exceed 2 %. The aim is to develop a methodology for determining the error in determining this value, depending on the characteristics of the radiation beam. Dosimetric measurements of Trilogy S/N 3567 linac dose distributions have been carried out for achievement of the objectives, on the basis of which dose errors depending on the dose rate value, the accuracy of the beam quality and output factors determination, the symmetry and uniformity of the radiation field, the angular dependence of the linac radiation output were obtained. It was found that the greatest impact on the value of the error has the error in the output factors determination (up to 5.26 % for both photon energy). Dose errors caused by changing dose rate during treatment were different for two photon energies, and reached 1.6 % for 6 MeV and 1.4 % for 18 MeV. Dose errors caused by inaccuracies of the beam quality determination were different for two photon energies, and reached 1.1 % for 18 MeV and –0.3 % for 6 MeV. Errors caused by the remaining of the characteristic do not exceed 1 %. Thus, there is a possibility to express the results of periodic quality control of the linear accelerator in terms of dose and use them to conduct a comprehensive assessment of the possibility of clinical use of a linear accelerator for oncology patients irradiation on the basis of the calibration of radiation output.

The estimation of dynamic behavior of aircraft gas temperature sensors (GTS) has to be done only in certified air installations and be based on recorded experimental transient response in accordance with the departmental standard. Experimental transient response has hindrances of different nature and can influence the accuracy of identification of dynamic behaviour of GTS. We suggested a new method to increase the accuracy of identification of dynamic behavior of GTS. The method is based on the use of amplitude spectrum of signal composed of experimental transient response. Shaped signal is an impulse decaying signal satisfying a Dirichlet condition and Fourier transform can apply to it to get amplitude spectrum. We worked out the relation between amplitude spectrum of shaped signals and time constant of dynamic behaviour for three mathematical models of GTS. The research showed that the information about dynamic behaviour of standard aircraft GTS is located in LF part of amplitude spectrum in the range of 0 to 1 rad/s and to 3 rad/s. The study revealed that hindrance in the transient response at frequency higher than 3 rad/s did not influence the accuracy of results if to use LF part of amplitude spectrum for the identification of dynamic behaviour of GTS. The amplitude spectrum of shaped signal can be estimated by measuring equipment like LF spectrum analyzer or calculated by software package with the function of fast Fourier transform. The value of time constant of certain mathematical model of GTS can be realized with the help of regression analysis or the use of embedded resources of different data processing systems. Thus, the method gives an opportunity to increase the accuracy of identification of dynamic behavior of GTS. 

Due to the specific character of problems in the field of ionizing radiation spectroscopy, the R&D and making process of standard volumetric activity metal samples (standard samples) for calibration and verification of spectrometric equipment is not only expensive, but also requires the use of highly qualified experts and a unique specific equipment. Theoretical and experimental studies performed have shown the possibility to use imitators as a set of alternating point sources of gamma radiation and metal plates and their use along with standard volumetric activity metal samples for calibration of scintillation-based detectors used in radiation control in metallurgy. Response functions or instrumental spectra of such spectrometer to radionuclides like ¹³⁷Cs, ¹³⁴Cs, ¹⁵²Eu, ¹⁵⁴Eu, ⁶⁰Co, ⁵⁴Mn, ²³²Th, ²²⁶Ra, ⁶⁵Zn, ¹²⁵Sb+^125mTe, ¹⁰⁶Ru+¹⁰⁶Rh, ⁹⁴Nb, ^110mAg, ²³³U, ²³⁴U, ²³⁵U and ²³⁸U are required for calibration in a given measurement geometry. Standard samples in the form of a probe made of melt metal of a certain diameter and height are used in such measurements. However, the production of reference materials is costly and even problematic for such radionuclides as ⁹⁴Nb, ¹²⁵Sb+^125mTe, ²³⁴U, ²³⁵U  etc. A recognized solution to solve this problem is to use the Monte-Carlo simulation method. Instrumental experimental and theoretical spectra obtained by using standard samples and their imitators show a high compliance between experimental spectra of real samples and the theoretical ones of their Monte-Carlo models, between spectra of real samples and the ones of their imitators and finally, between experimental spectra of real sample imitators and the theoretical ones of their Monte-Carlo models. They also have shown the adequacy and consistency of the approach in using a combination of metal scattering layers and reference point gamma-ray sources instead of standard volumetric activity metal samples. As for using several reference point gamma-ray sources with radionuclide like ¹⁵²Eu, ²³²Th, ²²⁶Ra etc, they allow, in a combination of metal scattering layers, to compensate for the absorption of low energy gamma rays in the metal and to generate the desired response in the backscatter peak range, and finally to get the correct amplitude distribution that is equivalent to interaction effects that occur in the volumetric standard sample with radionuclide uniformly distributed in it.