Effect of inductance on the parameters of the plasma focus in a pulsed coaxial accelerator

Based on the physical analysis of the processes occurring in pulsed plasma accelerators, the pos­sibility of their use for the creation and study of a plasma focus is justified. In particular, the influence of inductance on the parameters of the plasma focus in kilojoule­range «Plasma focus» (PF) installations created on the basis of a pulsed coaxial accelerator is studied. An equivalent installation scheme is proposed and justified, based on the analysis of which the influence of the inductance of the circuit and the capacitance of the capacitor bank on the value of the maximum current and neutron output is analyzed, without taking into account the parameters of the spark gap and the conducting wires. Based on the theoretical estimate of the inductance of the installation, its most probable value is calculated. . It turned out that in the installations of the considered energy range, the inductance is approximately 7.5•10­7 Gn and depends on the capacitance of the capacitor bank. On the contrary, in installations with megajoule energy, the inductance does not depend on the number and capacity of capacitors, so that an increase in the latter does not affect the increase in current strength. Experimental and theoretical dependences of the discharge current on the applied voltage at different capacitances of the capacitor bank are obtained. A comparative analysis of theoretical and experimental current waveforms is pre­sented. The greatest coincidence of theoretical and experimental results was found for the duration of the discharge pulse T = 30 microseconds.

Effect of inductance on the parameters of the plasma focus in a pulsed coaxial accelerator

The article considers some pedagogical and methodological aspects of the transition from the traditional system of education to teaching on the updated content of education in the framework of classroom and distance forms. The main objectives of the research were to study the effectiveness of using of criteria-based assessment, develop optimal short-term lesson plans and methodological materials for them. At the same time, the main attention is focused on the analysis of formative and summative assessment using interactive methods. As a result of the research, systematic methodological materials for physics lessons of various types were developed. The criterion of their effectiveness was a pedagogical experiment conducted in several schools in the Petropavlovsk. In the article presents diagrams of the results of determining the effectiveness of the new developed materials using interactive teaching methods during the criterion assessment of student success. During the pedagogical experiment the study of physics in high grades of the secondary school occurred in synchronous and asynchronous formats of distance learning. The results of the pedagogical experiment allow to speak about the positive influence of these methods on the progress of students.

Исследование коаксиального ускорителя плазменной струи

Results of main energy parameters of plasma jet investigation of coaxial accelerator with a conical insert in the region of discharge formation are presented. The dependences of the pressure and diameter of the deuterium plasma jet on the distance to the accelerator as well as its length and voltage polarity on the electrodes are obtained. The square growth of plasma jet energy with increasing voltage is shown. Among all the tested modifications the most effective was an accelerator with length not exceeding 220 mm, negative voltage polarity at the central electrode and focusing conical insert at the beginning of the outer electrode. Deuterium plasma with ionization front velocity of more than 100 km/s and pressure of more than 1 MPa at the source output was obtained. Method for measuring jet pressure using a deflecting screen and FLIR SC7300M infrared camera is presented.

Расчет и анализ электрофизических процессов в мощном импульсном ускорителе плазмы с собственным магнитным полем

We have considered basic theoretical models describing various aspects of the formation and acceleration of plasma in pulsed accelerators. The discharge current, magnetic field, and plasma bunch velocity have been determined experimentally at different initial gas pressures in the accelerator chamber. We have considered the correspondence of some theoretical models of plasma acceleration to experimental data obtained in a KPU-30 coaxial accelerator. It is shown that the formation of the plasma in the coaxial accelerator depends on the plasma density, and acceleration processes at densities higher and lower than a certain transient density value on the order of 10^11–10^12 cm^–3 are different. At a density higher than this critical value, the plasma is accelerated by a magnetic force. At the same time, at a low plasma density, plasma can be accelerated by an internal electric field.