The PCA correction method consists of a global analysis of turn-by-turn data obtained from beam position monitors (BPMs). One of its main advantages is speed of operation and the ability to detect pulsating power supplies. Along with this, a wide range of applications characterizes the PCA method: determination of perturbations of the accelerator magnetic structure, calculation of transport matrix elements and optical functions, and determination of the magnitude of the transverse coupling. A software prototype implementing the proposed correction method was written and tested on the electron-positron collider VEPP-4M for experimental validation. In the experiments, perturbations were introduced one by one into individual elements of the skew-quadrupole and quadrupole corrections. In one case, the excitation of betatron oscillations was carried out by the kick of the inflector. In another case, the oscillations were excited by resonant swing with a depolariser. It was found that, despite the simplicity of practical implementation, the examined method has some nuances that make it difficult to obtain and identify correct results. Nevertheless, it was possible to identify the introduced perturbations of quadrupole and skew-quadrupole corrections. Moreover, it was possible to detect a magnet with low-frequency pulsations by characteristic changes in the estimated invariants. In addition, the possibility of determining the integral coupling parameters in experiments on the observation of resonantly excited eigen modes having the shape of ellipses in the plane transverse to the beam motion axis is considered.

This article presents the results of calculations of C-designed dipole magnets that will be located in the SKIF storage device, four horizontal dipole magnets for the transport channel from LINAC to the booster and three dipole magnets for the channel from the booster to the storage device. The required field quality in the integral sense for the dipoles should be no worse than 5 × 10-4.

The Vacuum Insulated Tandem accelerator have been developed in Budker Institute of Nuclear Physics. Neutrons are generated in ⁷Li(p,n)⁷Be reaction. Neutron beam shaping assembly is used for therapeutic beam forming. It consists of the moderator, reflector and filter. Magnesium fluoride is considered optimal material for neutron slowing down because of noticeable cross section of inelastic neutron scattering. Previously, we showed that it is optimal to use proton beam at energy 2.3 MeV for neutron generation.

As a result of a critical analysis of our earlier decisions on the methods used to form a therapeutic neutron beam and decisions of other research groups, as well as successful experiments on the irradiation of laboratory pets and cell cultures carried out at our experimental facility, we noticed that with the recent trend towards a decrease in proton energy the process of inelastic scattering in MgF₂ is no longer decisive in neutron moderation, and it was decided to consider materials based on plexiglass as a moderator material.

In this work we considered Poly-Biz as moderator material and get the neutron beam the same quality as with MgF₂ moderator and proton energy 2.3 MeV but at lower proton energy and current that can cause treatment time reducing and allows more reliable neutron generation.For a long time, the development of BNСT was hindered by the lack of charged particle accelerators that provide stable production of a stationary 2.5 MeV 10 mA proton beam. The use of BSA with Poly-Biz allows the use of these accelerators at lower energy, which improves the reliability of their operation, and reduces the therapy time by more than 2 times, which is also important for therapy. Also, the use of such an BSA simplifies the requirements for a charged particle accelerator and this opens up both the possibility of optimizing the developed accelerators and the use of other accelerators that have not yet reached the required parameters.

The work studies how a plasma discharge in the Gas Dynamic Trap (GDT) is ignited in a volume significantly exceeding the volume of the injected electron beam. This property of a beam-plasma discharge makes it attractive to use relatively low-power electron beams to create starting plasma in open traps with parameters sufficient for its further effective heating by the neutral injection. Despite the fact that effective ionization of plasma far beyond the electron beam in open traps has been observed experimentally for more than 60 years, the detailed mechanism of this phenomenon is still not clear. Particularly many questions arise in regimes that are implemented in such large fusion facilities as GDT, where the relaxation length of the beam turns out to be significantly less than the length of the trap, and the turbulence excited by the beam is localized near the entrance magnetic mirror. Based on recent experiments [E.I. Soldatkina et al. Nucl. Fusion 62, 066034 (2022)], we have proposed a scenario for the development of a discharge in GDT, according to which a compact region of intense plasma turbulence first rapidly expands radially, ionizing the gas outside the beam tube in the vicinity of a magnetic mirror, and then a slower ionization process begins in the rest trap volume both due to the tail of suprathermal particles that are formed in the turbulence zone, and due to thermal electrons that receive energy from the pumping region via the longitudinal electron thermal conductivity. To assess how well this scenario explains the experimentally observed dynamics of plasma density growth in different parts of the facility, we carry out particle-in-cell simulations of the radial expansion of the turbulence zone and propose a simplified model of impact ionization in the entire volume of the trap by both thermal and suprathermal electrons.

In this work, the temperature dependence of the specific heat capacity of glasses obtained on the basis of the Na₂B₄O₇ + Bi₂O₃ compound with different concentrations of sodium tetraborate and bismuth oxide in the initial mixture was studied experimentally during cooling. It has been experimentally shown that with a change in the concentration of the initial substances, the specific heat capacity of the sample’s changes, and a shift of the maxima towards low temperatures is observed with an increase in the concentration of bismuth oxide. A physical interpretation of the nature of the maximum on the temperature dependence of the specific heat is given.

The electrical parameters of the semiconductor-metal phase transition in vanadium dioxide nanostructures synthesized by chemical vapor deposition on a silicon substrate (100) and decorated with gold nanoparticles with a surface concentration from 3∙10⁹ to 3∙10¹⁰ cm^–2 are studied. X-ray phase analysis revealed that the synthesized nanostructures of vanadium dioxide contain a monoclinic M1 phase undergoing a phase transition at a temperature of about 68 °C. The morphology of the surface of vanadium dioxide nanostructures coated with gold nanoparticles was studied using a scanning electron microscope and an atomic force microscope. The characteristics of the temperature phase transition of the initial nanostructures and nanostructures decorated with gold nanoparticles are determined. The temperature dependence of the resistance near the phase transition point of the initial nanostructures showed that the resistance jump is about four orders of magnitude, which confirms their high quality. It is shown that an increase in the surface concentration of gold particles to a value of 3∙10¹⁰ cm^–2 increases the conductivity of vanadium dioxide at room temperature by about two times, and shifts the phase transition temperature by 5 °C: from 68 °C to 63 °C. Optical switching in vanadium dioxide with an array of gold particles with a size of 9 nm is considered by numerical modeling methods. It is established that the response of the electromagnetic wave from the VO₂ material during the phase transition is enhanced due to the excitation of localized plasmon resonance in gold nanoparticles and reaches a local maximum in the region of 600 nm. Additionally, this effect is enhanced at angles of incidence near the pseudo-Brewster angle for vanadium dioxide. The considered hybrid VO₂–Au nanostructures are promising as basic nanoelements for next-generation computers, as well as for ultrafast and highly sensitive sensors.

Composite, copper and zinc containing nanoparticles and brass nanoparticles have been obtained by a high-performance method of evaporation of substances by a relativistic electron beam. The change in the stoichiometry of nanopowders produced by stepwise irradiation of a brass ingot placed in a single-zone graphite crucible is considered. It was found that the production of such particles depends on the concentration of saturated vapors of zinc and copper. A two-zone configuration of the crucible has been developed, which makes it possible to realize the simultaneous evaporation of the constituent components, thereby providing the conditions for the formation of uniform brass nanoparticles with a uniform distribution of elements and a high yield of nanopowder. X-ray diffraction analysis (XRD), Transmission electron microscopy (TEM), Energy dispersive X-ray analysis (EDX) were carried out, and the specific surface of the obtained nanoparticles was determined. The mechanism of formation of composite nanoparticles is discussed.

The process of hydrogen production through thermocatalytic decomposition of methane using a “nickel on kieselgur” catalyst on a quartz sand substrate with a thickness of 1 cm in the “sand-catalyst-sand” configuration was investigated in this work. The experimental results revealed a dependence of the percentage yield of hydrogen on temperature within the temperature range of 530°C to 770°C. As a result, a hydrogen content of 68% in the gas mixture was achieved at the reactor outlet under the conditions of 770°C temperature and a methane flow rate of 2 l/h.

A derivation of the time-dependent Schrödinger equation from the time-independent one is considered. Instead of time, the coordinate of an additional degree of freedom, the clock, is introduced into the original time-independent Schrödinger equation. It is shown that the standard time-dependent Schrödinger equation can be obtained for the semiclassical clock only. For elucidation of the physical meaning of the equation obtained in this way, various types of clocks are discussed. In addition, the corresponding equation for the density matrix and formulas for the mean values of operators are derived.

With the help of the MathCAD mathematical package, solutions to problems using the heat balance equation were obtained, in which the heat capacity was calculated according to Debye theory, and spline interpolation of experimental data on heat capacity from the reference book was also used. The degree of helium ionization at a given temperature is calculated. An example of the influence of lithium impurity on the degree of hydrogen ionization is considered. The energy and pressure of neon in the region of multiple ionization are calculated. Isotherms of an ideal fermi gas are con structed. A graph of the Fermi-Dirac distribution function for various temperatures is constructed. The concentration of electrons and positrons at temperatures corresponding to the rest energy of electrons is calculated. These examples can be used in the educational process.