Based on the results of the experiments and numerical estimates, the authors hypothesize that the direction of propagation of the flow of high-energy electrons in a micropinch discharge is determined by the freezing of magnetic field lines into the plasma flow and the magnetization of electrons accelerated to high energies.

Based on the results of the experiments and numerical estimates, the authors hypothesize that the direction of propagation of the flow of high-energy electrons in a micropinch discharge is determined by the freezing of magnetic field lines into the plasma flow and the magnetization of electrons accelerated to high energies. Keywords: micropinch discharge, plasma, acceleration processes.

The technique is described and the results of studies of the spatial structure and dynamics of X-ray sources in the plasma of a micropinch discharge are presented. The applied technique made it possible to temporarily link the process of electron acceleration in a quasi-static electric field of a resistive nature to the process of forming a microstretch in a Z-pinch in a medium of heavy elements with a nanosecond time resolution.

Flows of ions with energies on the order of megaelectronvolts, which propagate both in the axial direction and in the direction perpendicular to the symmetry axis of the discharge, are recorded in a high-current low inductance vacuum spark. Estimates based on the measurements of the total charge of suprathermal electrons emitted from the region of the waist of the current channel in the axial direction, as well as the total number of ions of the indicated energies show that the recorded ion energies correspond quite well to the value that can be achieved as a result of the Coulomb explosion of the Debye waist layer at the stage preceding the radiation compression.

В низкоиндуктивной сильноточной вакуумной искре зафиксированы потоки ионов с энергиями порядка мегаэлектронвольт, распространяющиеся как в осевом, так и в перпендикулярном оси симметрии разряда направлении. Оценки, основанные на измерении полного заряда надтепловых электронов, испущенных из области перетяжки токового канала в осевом направлении, а также полного числа ионов указанных энергий, показывают, что зарегистрированные энергии ионов вполне соответствуют величине, достижимой в результате кулоновского взрыва дебаевского слоя перетяжки на стадии, предшествующей радиационному сжатию. Ключевые слова: микропинч, кулоновский взрыв, дебаевский слой.

In this paper we present experimental data on the generation of ions with MeV-energy in a Z-pinch discharge in a heavy-element medium. The calculations show that the escape of runaway electrons from the constriction region can lead to the production of a positive volume charge and then to the Coulomb explosion of plasma, which generates high-energy particles.

It has been demonstrated that a compact diffusion chamber is a high-efficiency X-ray detector in the spectral range of 0.17–0.20 nm. The camera has a high spatial resolution and a sensitivity sufficient for studying the features of the line spectrum of X-ray radiation from short-lived dense high-temperature plasma using diffraction spectroscopy methods.

A flow of ions with energies of about 3 MeV propagating in the direction perpendicular to the symmetry axis of discharge has been detected in high-current low inductance vacuum spark. Estimations show that the measured ion energies quite well correspond to the value that can be achieved as a result of “Coulomb explosion” of the waist of a plasma channel of discharge current at the stage preceding its radiation compression.

The efficiency of the diffusion chamber as a tool for diagnostics of pulsed high-temperature plasma in a single discharge is demonstrated. Creation of a diffusion chamber operating at a temperature exceeding the temperature of the ambient medium will make it possible to simplify the device design and operation. Based on the experimental data obtained with the help of the diffusion chamber by means of diffraction spectroscopy, a hypothesis is put forward on the advanced development of electron acceleration processes compared to the process of micropinch plasma decay caused by anomalous plasma heating.

AbstractA flow of ions with energies of about 3 MeV propagating in the direction perpendicular to the symmetry axis of discharge has been detected in high-current low inductance vacuum spark. Estimations show that the measured ion energies quite well correspond to the value that can be achieved as a result of “Coulomb explosion” of the waist of a plasma channel of discharge current at the stage preceding its radiation compression.

A technique for and results of studying the characteristic X-ray spectrum of micropinch radiation are presented. A compact diffusion chamber of the original design has been used as a radiation detector.

AbstractA technique for and results of studying the characteristic X-ray spectrum of micropinch radiation are presented. A compact diffusion chamber of the original design has been used as a radiation detector.

A technique for direct measurements of the current distribution over the surface of a target that is at a negative bias potential relative to the ground was developed and tested. Measurements were performed using a six-channel meter that transmitted the measured data through a wireless Bluetooth acquisition system. The trace of an ion flow on the target surface was visualized by the method of luminous beams. Examples of the measured current distributions on a target surface depending on the geometric and physical parameters of the ion-optical system of a Penning plasma source are presented.

In this paper methodology for direct measurement of current distribution on a target surface biased to the negative potential by the 6 channel profile monitor is described, measurement were transmitted with a Bluetooth wireless acquisition system. Also the beam trace in the target plane was monitored by photo camera. Examples of the current distributions on the target, depending on geometrical and physical parameters ion optical system of Penning ion source were presented.

The variation of the Kα–Kβ spectrum of a micropinch in an iron plasma of a high-current vacuum spark has been studied at detection in a single discharge using a compact diffusion chamber as a detector. The spatial separation of radiation has been performed by diffraction spectroscopy methods. Signatures of the advanced development of acceleration processes for the electron component as compared to the decay of the micropinch plasma caused by its anomalous heating have been found.

The spatial structure and dynamics of the plasma in a high current vacuum spark discharge are studied via pulsed shadowgraphy. The formation of cavities in the neck plasma at the end of pinching has been registered.

В литературе имеются свидетельства в пользу того, что плазменный канал тока в плотном Z-пинче может обладать достаточно сложной пространственной структурой [1—6]. Авторы настоящей работы использовали часто применяемые методы диагностики, а именно импульсное теневое фотографирование объекта и получение интегральных по времени изображений источников мягкого рентгеновского излучения с помощью камеры-обскуры для исследования пространственной структуры перетяжки плазменного канала тока в микропинчевом разряде. Сделана попытка дать объяснение полученным экспериментальным результатам.