Speaker
Dr
Ivan Ivanov
(Budker Institute of Nuclear Physics)
Description
Further advances of a multiple-mirror plasma confinement concept [1] previously developed in the Schegol and GOL-3 experiments in the BINP will continue with a new GOL-NB facility [2]. Unlike previous generations of traps, GOL-NB will focus on the quasi-stationary multiple-mirror confinement of neutral-beam-heated plasma with moderate parameters: $T \sim 30-100 eV$ and $n \sim 3\times10^{19}~m^{-3}$ The plasma will be confined in the 2-m-long central trap of GOL-NB which ends with two multiple-mirror solenoids. The solenoids are re-used parts of the GOL-3 magnetic system with 14 corrugation periods (elementary multiple-mirror cells) of 22 cm length. The multiple-mirror confinement theory requires that the ion free path length should be comparable with the magnetic field corrugation period. Plasma heating will be provided by two 0.75 MW neutral beams that should be captured by a low-temperature start plasma created by an arc plasma gun installed in magnetic expander.
In this paper, we will present new experimental results on a magnetic compression and transport of a low-temperature arc plasma along the solenoid at $\sim$3 m distance. The magnetic compression ratio varied from 5 to 60, the initial plasma stream diameter was about 5 cm. Theory predicts that the multiple-mirror magnetic field should not significantly decelerate and weaken the collisional low-temperature arc plasma stream. In the experiment, we compared the transport efficiency of the plasma stream in the multiple-mirror configuration of the solenoid with the same in a uniform solenoidal field [3]. As the results the plasma with $(1-4)\times10^{20}$ $m^{-3}$ density at the axis was obtained at $\sim$3 m distance from the arc plasma source. The experiments simulated the baseline scenario of GOL-NB filling by the start plasma. Finally, the experiments described in the paper validated the decisions made for the GOL-NB start plasma source.
1. G. I. Budker et al., Influence of Corrugation of Magnetic Field on Expansion and Cooling of a Dense Plasma // JETP Lett., 14, 212 (1971).
2. V.V. Postupaev et al., Status of GOL-NB Project // This Conference.
3. V. V. Postupaev, et al., Experiments on the Transportation of a Magnetized Plasma Stream in the GOL-3 Facility. // Plasma Phys. Reports, 42, 319 (2016).
Primary author
Dr
Ivan Ivanov
(Budker Institute of Nuclear Physics)
Co-authors
Dr
Alexander Burdakov
(Budker Institute of Nuclear Physics)
Mr
Andrey Rovenskikh
(Budker Institute of Nuclear Physics)
Mr
Konstantin Kuklin
(Budker Institute of Nuclear Physics)
Dr
Vladimir Batkin
(Budker Institute of Nuclear Physics)
Dr
Vladimir Burmasov
(Budker Institute of Nuclear Physics; Novosibirsk State University)
Dr
Vladimir Postupaev
(Budker Institute of Nuclear Physics)
Mr
konstantin mekler
(Budker Institute of Nuclear Physics)
