Article describes the new type of multiphase flowmeter – “Ural-MR” developed by Corporation Uraltechnostroy LLC. Its operation is based on single physical principle: all flow parameters are evaluated with X-ray radiation analysis. Currently last steps of certification procedure are held, mass production procedure is been worked out. Design of the flowmeter, basic operation principles and demonstrative results are presented in the article.

The shape and size of the projection of the focal spot of an x-ray tube largely depend on the direction of the beam, which results in a spatial difference of the point spread function (PSF) of the imaging system. A model developed for determining the PSF at an arbitrary point of the radiation field is presented in this article. The input data for the model are the geometric parameters of the system, the measured magnified projection of the effective focal spot, and the PSF in the internal structure of the detector. The difference in the width of the profiles of the PSF between the experimental and modeled data does not exceed 7.2%. The projection images are reconstructed by means of a deconvolution algorithm using the modeled PSF. The frequency–contrast characteristics of the images show improvement compared with the initial image.

The purpose of this work is to investigate the factors determining the magnitude and nature of the lag effect (residual signal) in the Varian PaxScan 4343CB flat-panel detector. Depending on the detector mode, typical value of residual signal is 1-2% after single exposed frame, increasing up to 3% after multiple exposures. The lag effect is the cause of up to 3.6% error of average flat-field signal measurement if used for averaging series of continuously exposed frames, which leads to incorrect assessment of X-ray attenuation coefficients. Spatial dependence of the lag effect is confirmed; the results of correction of projection images using spatially localized impulse response functions are demonstrated.

In 1903, on the basis of Morozov Institute of the Moscow Imperial University (currently, P. Herzen Moscow Oncology Research Center, a branch of the National Medical Research Radiological Center, Ministry of Health of the Russian Federation), the first specialized unit in Russia was opened – department of radiation therapy of oncological diseases, in which scientific research in the field of medical radiology was officially launched in our country for the first time. The first studies in the field of radiation therapy can be attributed to this period. The article presents a brief summary of the historical development of radiotherapy in the world and in Russia; provides information on the achievements of global importance, fundamental for this scientific field. The activities of leading Russian organizations in the field of radiation therapy are reviewed; names of scientists, doctors and other specialists who have made a significant contribution to its development are provided. The main literature sources relevant to the field are given. The data in this article may be of interest and be useful for biomedical scientists, practicing radiologists and radiotherapists, oncologists, medical and graduate students, interns and other specialists.

The 15th author’s name should read I. A. Gulidov. The caption for Fig. 3 on page 336 should read

In Fig. 5 on page 341, the units for the X and Z axes should read cm. In Fig. 6 on page 341, the units for the X and Y axes should read cm.

In 1903, on the basis of Morozov Institute of the Moscow Imperial University (currently, P. Herzen Moscow Oncology Research Center, a branch of the National Medical Research Radiological Center, Ministry of Health of the Russian Federation), the first specialized unit in Russia was opened – department of radiation therapy of oncological diseases, in which scientific research in the field of medical radiology was officially launched in our country for the first time. The first studies in the field of radiation therapy can be attributed to this period.The article presents a brief summary of the historical development of radiotherapy in the world and in Russia; provides information on the achievements of global importance, fundamental for this scientific field. The activities of leading Russian organizations in the field of radiation therapy are reviewed; names of scientists, doctors and other specialists who have made a significant contribution to its development are provided. The main literature sources relevant to the field are given.The data in this article may be of interest and be useful for biomedical scientists, practicing radiologists and radiotherapists, oncologists, medical and graduate students, interns and other specialists.

Solid state amplification technology had developed a lot in recent years. This article is focused on a power combining system of a new power amplifier stage for ISIS neutron source (Rutherford Appleton Lab., STFC, UK). The amplifier is based on a modular block-built architecture that intends using of amplifier modules and combination of their output power (of >kW levels) using high power RF combiners. The power combining system for high power RF amplifier is discussed in this article. The system scheme together with results of modeling, low power measurements of key electrodynamic characteristics and high power operation test are presented.

Main parameters of digital flat panel detectors, to be taken into account in developing imaging systems are considered. Various factors affecting obtained images are presented. Experimental results presented confirm the necessity of image correction.

A high power solid-state RF amplifier system has been developed and tested. The modular scalable architecture of the system allows to build megawatt-range compact, robust, cost effective RF amplifiers/generators with high plug efficiency. Using a special designed technology of RF power on-board combination for several LDMOS transistors and very compact high power RF combiners, the amplifier with output power of 100 kW and duty cycle of 5% has been fit into a single 19 cabinet. The system has been tested at the output power up to 104 kW with 3.5 ms pulses. The overview of the technologies, the design of the machine, and its main subsystems is given in this talk. The test results and the market perspectives are also presented.

We introduce first results of our research in a promising approach for micro focal x-ray generation. The approach combines the use of liquid metal jet target as anode and carbon based nanostructures as field emission cathode. Results of metal jet break-up CFD simulation and cold cathode performance tests are described. The planned experimental program is discussed herein as well.

In this paper, we present the performance of 72 MHz 18 kW RF power source developed for cyclotrons. The machine is equipped with 9 class-AB power amplifier modules (each with up to 2 kW output) based on highly reliable LDMOS transistors. The whole system is arranged inside a single 19" cabinet and has coaxial 50 Ω output. The test environment and high power measurement results are described.

In this paper, we present the current status of the RF power amplifier under development for European Spallation Source (ESS, Sweden) normal conducting and superconducting accelerating sections based on solid-state architecture. A single 400 kW pulsed machine is represented with four standard 19 cabinets. Brief description and technical solutions regarding 8 kW (Class-AB, Si transistor based) RF modules, different power combiners and control system are shown.

Liquid jet injection into a quiescent gaseous environment has been experimentally and analytically studied covering subcritical to supercritical conditions. The focus was placed on the influence that the surrounding gas pressure and temperature have on the jet breakup. Under subcritical conditions, the surrounding gas inertia and surface tension forces controlled this process with ligament formation from which the material broke off and the drops, later, formed. Decreasing surface tension influenced the jet surface behavior under transcritical conditions: Ligament formation was significantly reduced under these conditions with only occasional drop formation. Further increasing the pressure and temperature led to supercritical breakup modes. This manifested through a smoothening of the liquid-gas interface. Ligament formation was not observed under supercritical conditions; this indicated that surface tension did not play any role in the supercritical jet breakup. The experimental technique, using planar laser induced fluorescence, revealed important core jet structures previously undetected. A linear jet stability analysis was, then, performed to gain physical insight into the jet breakup mechanisms. The results showed good correlation with experimental results under subcritical mixing but failed to predict the transcritical and supercritical regimes.

Experimental studies of multipulse detonations of n-hexane spray in air initiated by successively triggered electric discharges are presented. Similar to a single-shot mode reported previously, the multipulse operation mode shows the same resonant dependence of the detonation initiation energy on the time delay between the discharges. There is a potential of a considerable decrease in the detonation initiation energy per operational pulse. The issue of operational control aimed at avoiding misfires appeared to be important.