| 1. |
- Moiseenko, V. E., et al.
(författare)
-
Stellator research at IPP KIPT : Status and prospects
- 2019
-
Ingår i: PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. - : KHARKOV INST PHYSICS & TECHNOLOGY. - 1562-6016. ; :1, s. 3-8
-
Tidskriftsartikel (refereegranskat)abstract
- Features of the recent Uragan-2M campaign are reviewed together with some theoretical advances. They include experiments with B4C limiter, studies of various 1. . . 20 kHz oscillations, development of a new in-situ diagnostics for wall conditions, i.e. the thermal desorption probe, the improved numerical model of RF plasma production in stellarators in the ion cyclotron and electron-cyclotron frequency ranges, a new positive-definite form of time-harmonic Maxwell's equations and plasma start-up studies.
|
|
| 2. |
|
|
| 3. |
- Moiseyenko, Volodymyr, et al.
(författare)
-
Plasma Production in ICRF in the Uragan-2M Stellarator in Hydrogen–Helium Gas Mixture
- 2022
-
Ingår i: Journal of fusion energy. - : Springer. - 0164-0313 .- 1572-9591. ; 41:2
-
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.
|
|
| 4. |
|
|
| 5. |
- Kovtun, Yu.V., et al.
(författare)
-
ICRF plasma production in gas mixtures in the Uragan-2M stellarator
- 2023
-
Ingår i: Fusion engineering and design. - : Elsevier BV. - 0920-3796 .- 1873-7196. ; 194
-
Tidskriftsartikel (refereegranskat)abstract
- This paper summarizes previous results and presents new studies on the ICRF plasma creation both in pure gases and gas mixtures. In all the experiments, the two-strap antenna was operated in monopole phasing with applied RF power of ∼100 kW. The research for plasma creation was carried out at RF frequencies near the fundamental hydrogen cyclotron harmonic.
|
|
| 6. |
- KOVTUN, Yurii V., et al.
(författare)
-
ICRF Plasma Production with the W7-X Like Antenna in the Uragan-2M Stellarator
- 2022
-
Ingår i: Plasma and Fusion Research. - : Japan Society of Plasma Science and Nuclear Fusion Research. - 1880-6821. ; 17:0
-
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.
|
|
| 7. |
- Moiseenko, V. E., et al.
(författare)
-
Fast ion motion in the plasma part of a stellarator-mirror fission-fusion hybrid
- 2016
-
Ingår i: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 0741-3335 .- 1361-6587. ; 58:6
-
Tidskriftsartikel (refereegranskat)abstract
- Recent developments of a stellarator-mirror (SM) fission-fusion hybrid concept are reviewed. The hybrid consists of a fusion neutron source and a powerful sub-critical fast fission reactor core. The aim is transmutation of spent nuclear fuel and safe fission energy production. In its fusion part, a stellarator-type system with an embedded magnetic mirror is used. The stellarator confines deuterium plasma with moderate temperature, 1-2 keV. In the magnetic mirror, a hot component of sloshing tritium ions is trapped. There, the fusion neutrons are generated. A candidate for a combined SM system is a DRACON magnetic trap. A basic idea behind an SM device is to maintain local neutron production in a mirror part, but at the same time eliminate the end losses by using a toroidal device. A possible drawback is that the stellarator part can introduce collision-free radial drift losses, which is the main topic for this study. For high energy ions of tritium with an energy of 70 keV, comparative computations of collisionless losses in the rectilinear part of a specific design of the DRACON type trap are carried out. Two versions of the trap are considered with different lengths of the rectilinear sections. Also the total number of current-carrying rings in the magnetic system is varied. The results predict that high energy ions from neutral beam injection can be satisfactorily confined in the mirror part during 0.1-1 s. The Uragan-2M experimental device is used to check key points of the SM concept. The magnetic configuration of a stellarator with an embedded magnetic mirror is arranged in this device by switching off one toroidal coil. The motion of particles magnetically trapped in the embedded mirror is analyzed numerically with use of motional invariants. It is found that without radial electric field particles quickly drift out of the SM, even if the particles initially are located on a nested magnetic surface. We will show that a weak radial electric field, which would be spontaneously created by the ambipolar radial particle losses, can make drift trajectories closed, which substantially improves particle confinement. It is remarkable that the improvement acts both for positive and negative charges.
|
|
| 8. |
- Moiseenko, V. E., et al.
(författare)
-
Research on stellarator-mirror fission-fusion hybrid
- 2014
-
Ingår i: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 0741-3335 .- 1361-6587. ; 56:9, s. 094008-
-
Tidskriftsartikel (refereegranskat)abstract
- The development of a stellarator-mirror fission-fusion hybrid concept is reviewed. The hybrid comprises of a fusion neutron source and a powerful sub-critical fast fission reactor core. The aim is the transmutation of spent nuclear fuel and safe fission energy production. In its fusion part, neutrons are generated in deuterium-tritium (D-T) plasma, confined magnetically in a stellarator-type system with an embedded magnetic mirror. Based on kinetic calculations, the energy balance for such a system is analyzed. Neutron calculations have been performed with the MCNPX code, and the principal design of the reactor part is developed. Neutron outflux at different outer parts of the reactor is calculated. Numerical simulations have been performed on the structure of a magnetic field in a model of the stellarator-mirror device, and that is achieved by switching off one or two coils of toroidal field in the Uragan-2M torsatron. The calculations predict the existence of closed magnetic surfaces under certain conditions. The confinement of fast particles in such a magnetic trap is analyzed.
|
|
| 9. |
- Moiseenko, V. E., et al.
(författare)
-
Stellarator-mirror fusion-fission hybrid - a fast route to clean and safe nuclear energy
- 2023
-
Ingår i: Journal of Plasma Physics. - : Cambridges Institutes Press. - 0022-3778 .- 1469-7807. ; 89:4
-
Tidskriftsartikel (refereegranskat)abstract
- The multiple-recycle fuel cycle for uranium-238 considered here, if practically realized, can bring revolutionary changes in nuclear energy. A full use of uranium-238 implies a practically infinite resource for power generation. Besides the energy, the fuel cycle net output is only fission products, which are co-products rather than waste. For the same amount of energy produced, the amount of fission products is two orders of magnitude less compared with the amount of spent nuclear fuel generated in currently exploited nuclear energy production scenarios. Using the simplest isotope balance model, key features of the multiple-recycle fuel cycle for uranium-238 are investigated. The repetition of this cycle results in smooth transformation of the initial fuel to 'stationary' fuel without strong variations in the fractional isotope content. Deficit of delayed neutrons is a threat of the fuel cycle considered as well as other fuel cycles that use plutonium. It has a dramatic impact on reactor controllability and safety. A solution to this threat could be a subcritical nuclear reactor with an external neutron source. In this paper, use of a stellarator-mirror (SM) fusion-fission hybrid for the multiple-recycle fuel cycle for uranium-238 is analysed. A summary of the experimental and theoretical studies on the SM hybrid is given. Preliminary results for principal design of a SM hybrid nuclear reactor for the multiple-recycle fuel cycle for uranium-238 are presented.
|
|
| 10. |
|
|
| 11. |
- Moiseyenko, Volodymyr, et al.
(författare)
-
FUSION RESEARCH IN STELLARATOR DEPARTMENT OF IPP NSC KIPT
- 2022
-
Ingår i: PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. - : Problems of Atomic Science and Technology. - 1562-6016. ; :6, s. 3-8, s. 3-8
-
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.
|
|
| 12. |
- Kamio, S., et al.
(författare)
-
First experiments on plasma production using field-aligned ICRF fast wave antennas in the large helical device
- 2021
-
Ingår i: Nuclear Fusion. - : Institute of Physics (IOP). - 0029-5515 .- 1741-4326. ; 61:11
-
Tidskriftsartikel (refereegranskat)abstract
- The results of the first experimental series to produce a plasma using the ion cyclotron range of frequency (ICRF) in the large helical device (LHD) within the minority scenario developed at Uragan-2M (U-2M) are presented. The motivation of this study is to provide plasma creation in conditions when an electron cyclotron resonance heating start-up is not possible, and in this way widen the operational frame of helical machines. The major constraint of the experiments is the low RF power to reduce the possibility of arcing. No dangerous voltage increase at the radio-frequency (RF) system elements and no arcing has been detected. As a result, a low plasma density is obtained and the antenna-plasma coupling is not optimal. However, such plasmas are sufficient to be used as targets for further neutral beam injection (NBI) heating. This will open possibilities to explore new regimes of operation at LHD and Wendelstein 7-X (W7-X) stellarator. The successful RF plasma production in LHD in this experimental series stimulates the planning of further studies of ICRF plasma production aimed at increasing plasma density and temperature within the ICRF minority scenario as well as investigating the plasma prolongation by NBI heating.
|
|
| 13. |
- Moiseyenko, Volodymyr, et al.
(författare)
-
Developments for stellarator-mirror fusion-fission hybrid concept
- 2021
-
Ingår i: Problems of Atomic Science and Technology, Ser. Thermonuclear Fusion. - : NRC Kurchatov Institute. - 0202-3822. ; 44:2, s. 111-117
-
Tidskriftsartikel (refereegranskat)abstract
- Conceptual development activities on a stellarator-mirror-based fission-fusion hybrid system (SM hybrid) are reviewed. Intended fortransmutation of spent nuclear fuel and safe fission energy production, SM hybrid consists of a fusion neutron source and a powerful subcritical fast fission reactor core. Its fusion component is a stellarator with an embedded magnetic mirror. The stellarator allows for theconfinement of a moderately hot (1—2 keV) deuterium plasma. In the magnetic mirror, the hot sloshing tritium ions are trapped andfusion neutrons are generated. The magnetic mirror is surrounded by a fission mantle, where transmutation of minor actinides and energygeneration take place. One candidate magnetic confinement device for the SM hybrid is the advanced DRACON magnetic trap system,which, unlike the «classical» DRACON version, has one short, rather than two longer mirrors with a relatively short size of 3—6 m. Acomparative numerical analysis of collisionless losses occurring in the magnetic trap part of the single-mirror DRACON leads to a conclusion about the possibility for high-energy tritium ions to be fairly well confined in the magnetic trap area. The Uragan-2M (U-2M)stellarator is used to test the SM hybrid concept with experiment. To fit a magnetic trap into U-2M system, one of the toroidal coils hadto be switched off. A radial escape of charged particles may spontaneously give rise to a weak radial electric field, which may result inclosing the particles’ drift trajectories and thereby substantially improve their confinement. Background plasma confinement withoutdestructive instabilities is demonstrated in the stellarator-mirror regime of U-2M) operation. The sloshing ions driven by radio-frequencyheating are detected in the mirror part of the device with NPA diagnostics. A novel fission mantle design for the SM hybrid is proposed.
|
|
| 14. |
- Moiseyenko, Volodymyr, et al.
(författare)
-
Status and prospects in stellarator research at ipp kipt
- 2021
-
Ingår i: Problems of Atomic Science and Technology. - : Problems of Atomic Science and Technology. ; 27:1, s. 3-8
-
Tidskriftsartikel (refereegranskat)abstract
- A review of works performed at the Stellarator Department of KIPT is presented. It includes radio frequency (RF) plasma start-up, RF wall conditioning, RF plasma heating and diagnostics improvements at Uragan stellarators, studies of discharges for wall conditioning at Wendelstein 7-X Helias and some theoretical studies on magnetic configurations and tritium breeding. The prospects for the studies are associated with deeper involvement in EUROfusion activities
|
|
