| 1. |
- KOVTUN, Yurii V., et al.
(författare)
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ICRF Plasma Production with the W7-X Like Antenna in the Uragan-2M Stellarator
- 2022
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Ingår i: Plasma and Fusion Research. - : Japan Society of Plasma Science and Nuclear Fusion Research. - 1880-6821. ; 17:0
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Tidskriftsartikel (refereegranskat)abstract
- The results of the plasma start-up with ICRH of U-2M RF discharges in H2+He mixture with newly implemented controlled gas H2 concentration are presented. The W7-X like ICRH antenna operated in monopole phasing with applied RF power of ∼ 100 kW. We investigated plasma start-up in the pressure range p = 6×10−4 - 9 × 10−2 Pa. Plasma production with an average density of up to Ne ∼ 1013 cm−3 was observed at frequencies the fundamental harmonic of the hydrogen cyclotron frequency.
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| 2. |
- Moiseyenko, Volodymyr, et al.
(författare)
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FUSION RESEARCH IN STELLARATOR DEPARTMENT OF IPP NSC KIPT
- 2022
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Ingår i: PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. - : Problems of Atomic Science and Technology. - 1562-6016. ; :6, s. 3-8, s. 3-8
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Tidskriftsartikel (refereegranskat)abstract
- This paper briefly describes intrinsic and collaborative scientific activities in the Stellarator Department of the Institute of Plasma Physics of the National Science Center "Kharkov Institute of Physics and Technology" in last two years. These activities include experiments on JET tokamak, stellarators Wendelstein 7-X and Uragan-2M, TOMAS toroidal device and theoretical studies related to modeling of radio-frequency fields in plasma and conceptual development of the stellarator-mirror fission-fusion hybrid.
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| 3. |
- Moiseyenko, Volodymyr, et al.
(författare)
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Plasma Production in ICRF in the Uragan-2M Stellarator in Hydrogen–Helium Gas Mixture
- 2022
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Ingår i: Journal of fusion energy. - : Springer. - 0164-0313 .- 1572-9591. ; 41:2
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Tidskriftsartikel (refereegranskat)abstract
- Plasma production experiments in helium at Uragan-2M have been performed to investigate the role of the hydrogen minority in helium. The experiments presented here were carried on with a controlled minority hydrogen concentration. The hydrogen minority allowed one to increase plasma density more than three times as compared with pure helium. The obtained plasma density is highest for whole time of Uragan-2M operation. The developed scenario allowed to decrease the neutral gas pressure at which the plasma production is possible. This is a requirement for achieving regimes of plasma production with full ionization. Although the initial gas mixture 14%H2 + 86%He can be treated as optimum, there is no sensitive dependence on hydrogen minority concentration, which makes the scenario robust. This study, together with initial LHD experiments, confirm the prospects of target plasma production by ICRF waves for stellarator type machines.
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| 4. |
- Sunn Pedersen, Thomas, et al.
(författare)
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Experimental confirmation of efficient island divertor operation and successful neoclassical transport optimization in Wendelstein 7-X
- 2022
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 0029-5515 .- 1741-4326. ; 62:4, s. 042022-042022
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Tidskriftsartikel (refereegranskat)abstract
- We present recent highlights from the most recent operation phases of Wendelstein 7-X, the most advanced stellarator in the world. Stable detachment with good particle exhaust, low impurity content, and energy confinement times exceeding 100 ms, have been maintained for tens of seconds. Pellet fueling allows for plasma phases with reduced ion-temperature-gradient turbulence, and during such phases, the overall confinement is so good (energy confinement times often exceeding 200 ms) that the attained density and temperature profiles would not have been possible in less optimized devices, since they would have had neoclassical transport losses exceeding the heating applied in W7-X. This provides proof that the reduction of neoclassical transport through magnetic field optimization is successful. W7-X plasmas generally show good impurity screening and high plasma purity, but there is evidence of longer impurity confinement times during turbulence-suppressed phases.
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