The project of a small-sized pulsed neutron generator with a laser deuteron source with magnetic isolation has been proposed with a modification of a pulsed high-voltage Tesla transformer used as the accelerating voltage source. In this case, the electronic conductivity is suppressed by the magnetic field excited in the primary circuit of the transformer. The electrodynamic parameters of the generator diode system have been estimated. The possibility of neutron generation using the Li(p, n)Be nuclear reaction has been shown, which opens up prospects for the effective use of the neutron generator in radiation therapy.

The beginning of an experimental study of a high-current discharge in a vacuum with a duration of less than 100 ns initiated by laser plasma is reported. Measurements of the discharge current, neutron output, and ion fluxes by collector technique are given. When the discharge current reaches 40 kA, dips of up to 30

The possibility of using synthetic diamond crystals as a sensitive element of resistive-type thermal sensors developed to control target heating in a neutron generator is discussed. Information about the design and manufacturing technology of a mock-up sample of the temperature sensor, as well as data from an experimental study of its dynamic characteristics, are given. On the example of a neutron generator developed based on a high-current accelerating diode, a scheme for thermal control of a neutron-forming target is proposed.

The article presents the results of modeling a diode accelerator for neutron generation with a laser deuteron source and a system for suppressing electronic conductivity by magnetic fields. Variants of the formation of an insulating magnetic field by annular permanent magnets and a spiral electrodynamic line are considered. The possibility of implementing an effective pulsed neutron generator based on such an accelerator is shown. The results of the conducted computer and physical experiments allow us to expect record values of the neutron energy price to be achieved using the T(d,n)4He nuclear reaction.

The issues of the influence of geometric conditions of laser radiation focusing on the surface of the plasma-forming target of an laser-plasma ion source are considered. In particular, the presence of two ion emission maxima in the region of the laser radiation flux density exceeding 1011 W/m2 has been experimentally established. A possible interpretation of this effect is proposed.

The article considers an in-situ method potential for establishing the surface distribution of tritium in the first wall of a fusion reactor using neutron tomography. The method includes the formation of a pulse-periodic flux of accelerated deuterons bombarding the studied surface of the first reactor wall following its saturation with tritium, generation of a fast neutron field according to T (d, n)4He reaction, measurement of neutron fluence at given spatial points, and reconstruction of the spatial tritium distribution according to measurement data. An algorithm for such a reconstruction is presented based on an approximate solution to the inverse Fredholm problem.

We present the simulation results of a diode accelerator for generating neutrons with a laser source of deuterons and a system for suppressing electronic conductivity by the pulsed magnetic field of a spiral line. The possibility of implementing an effective pulsed neutron generator based on the accelerator is shown. The results of computer and physical experiments allow us to hope for the possibility of creating a sealed accelerating tube with output parameters above 10 10 n/pulse as a result of T (d, n) 4 He nuclear reactions. A possible design for such an accelerating tube is proposed, and the technological feasibility of its implementation is substantiated.

The formation of ion fluxes of the laser plasma by axially symmetric magnetic fields is studied. An algorithm for forming ion fluxes is developed and a computer experiment is carried out. As a result of the computer and physical experiments, it is shown that ion packets with a duration exceeding several microseconds, which contain more than ~1012 particles at a flight distance of about 2 m, can be obtained at the output of a laser-plasma ion source.

The technique and results of measuring the soft X-ray emission spectra of a vacuum spark plasma with laser triggering for aluminum 13Al and iron 26Fe cathodes are presented. The use of a diagnostic technique based on thermoluminescent detectors of lithium fluoride LiF (Mg, Ti) makes it possible to study X‑ray radiation in the energy range of 0.2–15 keV quanta. These studies have shown that the X-ray yield of the plasma and the shape of the X-ray spectrum depend on the material of the discharge electrodes. The highest integral emission yield was observed for the aluminum cathode, while the contribution to the spectrum of the hard component prevailed for the iron cathode.

The sensitivities of laser-induced breakdown spectroscopy and quadrupole mass spectrometry are compared to determine the deuterium retained in titanium films using a nanosecond Nd:YAG laser. Simultaneous measurements are made in the 1–18 J cm −2 range of energy densities. Considerably higher sensitivity of mass spectrometry is revealed, along with the possibility of non-destructive analysis at low energy densities.

The efficiency of the laser-induced desorption method as a detector of hydrogen isotopes under pulsed laser irradiation (wavelength 1064 nm, 100 mJ, duration 10 ns) for different power densities of incident radiation on deuterium-saturated thin titanium films was investigated. When the power flow density increases by 16 times, the intensity of the thermal desorption peak increases by more than 2 orders of magnitude. Long-term repeated irradiation of the surface does not lead to significant depletion of the content of hydrogen isotopes in the studied layers, allowing their further ex-situ analysis.

In the Institute for Laser and Plasma Technologies of NRNU MEPhI a compact spherical tokamak MEPhIST (MEPhI-Spherical Tokamak) for educational, demonstration and research purposes is under development and construction. The creation of plasma diagnostics systems involves several stages, determined by the successive complication of the plasma researchtasks, the upgrading of the device and the development of educational and methodological material for laboratory work to be put at the tokamak. Working out in situ methods of plasma-surface interaction analysis is one of the main scientific and technological goals of this tokamak. The complex of diagnostics described in the paper provides complementary information about the processes occurring at plasma with surface contact, is a set of very informative and well-tested diagnostic tools that allow students to obtain visual and reliable information about the processes occurring in the discharge chamber of the tokamak.

The application of the laser-aided diagnostic using the nanosecond laser for direct measurement of hydrogen concentration on the walls of the Globus-M2 tokamak is under discussion. The D release after the laser irradiation with the fluence in the range of 0.1 - 4 J/cm2 was measured in laboratory experiments at the Large MEPhI mass-monochromator facility for W-D, Ti-D films, and for the W tile exposed in the Globus-M tokamak. The desorption flux was high enough to be detected during similar measurements inside the Globus-M2 tokamak. TMAP 7 modeling of D release from W-D films was done for the relatively low laser fluence (< 1 J/cm2). A reasonable agreement with experimental data has been achieved, and the depth of analysis was estimated.

The work presents the results of modeling the process of suppressing an electronic component in a small-sized coaxial ion diode by a pulsed magnetic field of a spiral electrodynamic line. Information was obtained on the features of this process, which is necessary for designing a diode with pulsed magnetic insulation.

The collective acceleration of laser plasma ions in a rapidly increasing magnetic field (108 T/s) excited by a powerful current pulse in a low-inductive conical spiral expanding in the direction of plasma acceleration has been studied. A mathematical model and an algorithm for calculating the radial Br and axial Bz components of the magnetic field in the approximation of a conical spiral by a system of rings of variable radius are proposed to analyze the factors affecting the efficiency of such acceleration. Based on computer modeling and an experimental variation of magnetic-field excitation parameters, the regime of effective ion acceleration is obtained. With the help of time-of-flight collector measurements, the velocities of ions whose atomic mass differs by two orders of magnitude are determined. The maximum velocity of both light ions (lithium) and heavy ions (lead) exceeds 106 m/s, and the corresponding energy for lead ions is ~1 MeV. The efficiency of collective acceleration with the direct acceleration of laser plasma ions in a high-current high-voltage diode with magnetic insulation is compared.

Surfaces facing the gap between W tiles of the ring limiter of tokamak T-10 were analyzed after T-10 decommissioning using LIBS, SEM/EDA, XRD, TDS, and NRA techniques. Gaps with the width of 5 mm and 0.1 mm were nearly completely covered to their full depths of 22 and 15 mm, respectively, by a deposited film. The film was formed mainly by deposition of lithium that came from Li limiter and transformed in air to Li2CO3 and Li2O. Carbon was deposited from volatile hydrocarbons sputtered from the tokamak walls. Besides, carbon appeared due to chemical reaction with lithium in air. Chemical interactions of W with C, O, and Li led to formation W2C, WC, WO2, and Li2WO4. Carbides formed in W over the entire surface to the full depth of the gaps. Trapping of deuterium and helium in tiles was demonstrated. Possible influence of auto-oscillating discharges on ionization and ion trapping of C,D, and He in gaps is discussed.

Abstract—The acceleration of a plasmoid, for the formation of which a conical spiral expanding in the direction of the expected plasma acceleration is used, in a rapidly increasing magnetic field of complex geometry has been considered. An algorithm for calculating the longitudinal magnetic field in the approximation of replacing a spiral line with a system of rings of variable radius has been presented. A mathematical model that is based on the interaction of the plasmoid magnetic moment with gradient of the longitudinal magnetic field decay has been proposed to analyze the efficiency of the acceleration. The possibility of deuterons reaching an average speed exceeding 10^6 m/s has been shown.