Recent results of studies of magnetic field distribution and neutron scaling on PF-1000 and PF-3 facilities

The recent results of studies of the magnetic field distribution and the neutron yield scaling in two largest plasma focus facilities, PF-3 and PF-1000 is done. The power-law dependence of the neutron yield on the current in the imploding plasma sheath has been demonstrated experimentally. For the first time the presence of the Вz magnetic field components is experimentally shown. In the compression stage, the axial component of the magnetic field reaches several kG that comprises ~10 % of the azimuthal component. The presence of the Bz field is a powerful argument in favor of the existence of closed magnetic configurations, which play an important role in the generating of neutrons.Представлены результаты последних исследований распределения магнитного поля и скейлинга нейтронного выхода на двух крупнейших плазмофокусных установках ПФ-3 и ПФ-1000. Экспериментально показана степенная зависимость нейтронного выхода от величины тока в сжимающейся плазменной оболочке. Впервые экспериментально показано наличие Вz-компоненты магнитного поля. В стадии сжатия величина аксиальной компоненты магнитного поля достигает нескольких килограмм-сил, что составляет ~ 10% от величины азимутальной компоненты. Наличие Bz-поля является весомым аргументом в пользу существования замкнутых магнитных конфигураций, играющих важную роль в механизме генерации нейтронов.Представлено результати останніх досліджень розподілу магнітного поля і скейлінга нейтронного вихoдy на двох найбільших плазмофокусних установках ПФ-3 та ПФ-1000. Експериментально показана ступенева залежність нейтронного виходу від величини струму в плазмовїй оболонці, що стикається. Вперше експериментально показано наявність Вz-компоненти магнітного поля. У стадії стиснення величина аксіальної компоненти магнітного поля досягає декількох кілограм-сил, що складає ~ 10 % від величини азимутальної компоненти. Наявність Вz-поля є вагомим аргументом на користь існування замкнутих магнітних конфігурацій, що мають неаби яку роль у механізмі генерації нейтронів

Propagation dynamics of successive emissions in laboratory and astrophysical jets and problem of their collimation

International audienceThe paper presents the results of numerical simulation of the propagation of a sequence of plasma knots in laboratory conditions and the astrophysical environment. The physical and geometric parameters of the simulation have been chosen close to the parameters of the PF-3 facility (Kurchatov Institute) and the jet of the star RW Aur. We found that the low-density region formed after the first knot propagation plays an important role for collimation of the subsequent ones. Assuming only the thermal expansion of the subsequent emissions, qualitative estimates of the time taken to fill this area with the surrounding matter and the angle of jet scattering have been made. These estimates are consistent with observations and results of our modeling

Progress in MJ plasma focus research at IPPLM

The results of studies of the plasma dynamics and neutron emission on a PF-1000 facility in the stage of pinch formation are presented. The measurements were performed using various modifications of the calibrated magnetic probes, 16 frame interferometry, silver activation counters and photomultiplier tube (PMT) neutron probes. The current measurements at a distance of 40 mm from the axis of the electrodes was measured. This dependence agrees well with the known scaling, Yn similar to I4. The evolution plasma density during pinch formation and a neutron emission were study

Evaluation of signal mode characteristics near the MOF for the purposes of the over-the-horizon radar

© 2019 IEEE. A comparative assessment of the characteristics of the upper and lower rays near the MOF is carried out. The method of oblique sounding of ionosphere by the chirp signals was used and paths of various lengths were used. It is shown that there are frequencies near the MOF which amplitudes of signals of the upper and lower rays are comparable. The difference between the times of group propagation is in the range of ∼ 40-460 μs, which corresponds to the range of distances of ∼ 15-140 km

Evaluation of signal mode characteristics near the MOF for the purposes of the over-the-horizon radar

© 2019 IEEE. A comparative assessment of the characteristics of the upper and lower rays near the MOF is carried out. The method of oblique sounding of ionosphere by the chirp signals was used and paths of various lengths were used. It is shown that there are frequencies near the MOF which amplitudes of signals of the upper and lower rays are comparable. The difference between the times of group propagation is in the range of ∼ 40-460 μs, which corresponds to the range of distances of ∼ 15-140 km