B. Yu. Bogdanovich

Throats as macroparticles on the basis of spherically symmetric solutions to the Einstein-Maxwell equations

Exact spherically symmetric solutions to the equations of general relativity for dust, the electromagnetic field and electrically charged dustlike matter, containing throats, are used for a gravitational description of macro- and microobjects like a universe, pinch plasmoids, and atomic nuclei. The observed universe is shown to be possibly a maximon. The nature of plasmoids forming in experiments with high-voltage discharges can be gravitational. A good agreement is observed between the estimated radii of atomic nuclei with high mass numbers based on the gravitational interaction and the empirical ones.

Analytical description of the charged particle dynamics in the field of a spherical magnetic dipole

The equations of charged particle motion in the earth’s magnetic field are analyzed. Analytical data allow us to estimate important parameters of the charge dynamics, such as the charge capture conditions, oscillation amplitude and frequency, and longitudinal drift, and also relate these parameters to the parameters of the charged particles and the height of their trajectory. The results may be used in designing space vehicles intended for investigation of the near-earth space, specifically, earth’s magnetosphere, with charged particle beams.

Applicability of a Conical Cavity as a Target for Generation of Neutrons in a Linear Accelerator

Results of the study are presented, which demonstrate the applicability of targets with a tapered surface of the reaction layer for generation of neutrons in linear accelerators of hydrogen nuclides in the nuclear reactions T(d, n)4He, T(p, n)3He, and D(d, n)3He. An algorithm is proposed for calculating the neutron yield, taking into account possible changes in the concentration of hydrogen isotopes in the target with depth. As a result of computer simulations, the dependence of the neutron yield on the cone angle has been established, and the possibility has been shown of increasing the neutron yield from a target with a conical surface of its reaction layer without changing its thickness.

Project of the borehole neutron generator for the direct determination of oxygen and carbon by activation method

The paper deals with application features of borehole neutron generator (BNG) based on the vacuum accelerating tube (AT) with laser-plasma ion source for determination of oxygen isotope 16O and carbon isotope 12C by direct activation. The project of pulsed BNG for realization of an activation method in the conditions of natural presence of productive hydrocarbons is offered. The diode system with radial acceleration, magnetic electron insulation and laser-plasma source of deuterons at the anode in a sealed-off vacuum accelerating tube is applied. The permanent NdFeB magnet with induction about 0.5 T for produce the insulating magnetic field in the diode gap is proposed. In the experiments on the model of BNG with the accelerating voltage source (≈350 kV), performed by the scheme of Arkadiev-Marx generator, the output of (d, d) neutrons was ~107 pulse-1.

Modification of the ferrous and nonferrous metals in the process of pinch discharges in the water vapor

Characteristics of a prospective method of modification of the structural-phase state and properties of materials in the process of pulsed electrical charges in water are given. Experimental results of the structural- phase changes in steels A-35, 30Kh3NMAF, and 45Kh2MFA and nonferrous metals (copper, titanium, and lead) under periodic discharge in a stream of fluid (PDSF) are presented. Formation of a compression wave with instant transition into an expansion wave creates strong local deformation and warm-up in the processed materials accompanied by formation of domains similar to metal pins in automotive rubber; rebuilding of the material structure and change in the phase state take place. The scope and extent of these changes with a fixed PDSF is determined by the nature of the alloy composition and susceptibility to structural transformations under level of pulsed exposure. Recommendations are given for the PDSF application for hardening of the material of various products, which extends the technological capabilities of modern engineering.

Neutron generators based on microwave sources of heavy hydrogen nuclides (Review)

Physical principles of operation of high-efficiency neutron accelerating tubes based on microwave heavy hydrogen nuclide sources using the electron-cyclotron resonance (ECR) effect are considered. The most promising domestic and foreign designs in this area are analyzed. Generation of electromagnetic oscillations in the working volume of the ion source of an accelerating tube with the boundary excitation of a microwave discharge is simulated. In this case, the resonator and waveguide modes of ECR plasma production are considered. The frequency dependences of the flux density of the energy transmitted from the alternating electromagnetic field to the electron plasma component, on the induction of the longitudinal magnetic field and the pressure in the discharge chamber are also given. The results of the performed studies may be used to develop efficient portable neutron generators based on accelerating tubes with microwave hydrogen nuclide sources.

Two-parameter correction of counting losses in radiation control systems based on linear accelerators

The problems in correcting counting losses in data acquisition sections of radiation monitoring systems based on linear accelerators are considered. In this case, the two-parameter dependence of the observed counting rate at the output of the detection systems on the true number of nuclear events is taken into account. Equations for calculating parameters of these dependences using data of the control test measurements have been obtained. The circuit for counting loss correction with allowance for the determined characteristics is discussed. The actual calibration process including the two-parameter correction for a neutron logging hardware-methodical complex comprising an accelerating tube is considered as an example. In the future, it is expected that test measurements will be taken on the linear resonant proton accelerator at the Radiation-Acceleration Center of the Moscow Engineering Physics Institute.

Method of intensifying electron Bremsstrahlung

A method of increasing the intensity of electron Bremsstrahlung by means of multiple passage of an electron beam through a conversion target placed in a magnetic field is described. After each passage through the conversion target, the diverging beam of electrons is focused in magnets with special pole pieces. To study the formation of the Bremsstrahlung flux the characteristics of the Bremsstrahlung of the 2–8 MeV electrons were calculated for aluminum, tin and tungsten targets of different thickness. This made it possible to choose the optimal target material and thickness.

A multibeam radio-frequency ion source with a discharge chamber inside a resonator

The design of a multibeam ion source with a discharge chamber inside a half-wavelength radio-frequency (RF) resonator with a spiral load is described. The resonator is excited by a loop insulated from the body of the resonator. The RF oscillator operating at a frequency of 38 MHz is grounded. The use of the resonator facilitates the initiation of a discharge at a low power level. The amplitude-frequency characteristics of the resonator at the operating frequencies of the ion source are presented. The effect of the RF power and the extracting voltage on the ion-beam current has been studied. The experimental results on the ion-beam extraction at a low RF power (<100 W) are presented.

High average power input couplers for superconducting cavities of charged particle accelerators

The heat and electrodynamic calculations of a power input coupler into superconducting cavities of an accelerator’s injector with energy recuperation are presented. The design of a double coaxial input of an average power of 2 × 75 kW is described. The heat losses in this device are <0.2, <3.5, and <75 W at temperatures of 2, 4, and 80 K, respectively. The external Q factor of the cavity can be adjusted. The design of the coupler can be modified for inputting an average power of 2 × 250 kW.