| 1. |
- Bykov, Igor, et al.
(författare)
-
Collection of mobile dust in the T2R reversed field pinch
- 2012
-
Ingår i: Nukleonika. - 0029-5922 .- 1508-5791. ; 57:1, s. 55-60
-
Tidskriftsartikel (refereegranskat)abstract
- Intensive plasma-wall interactions in fusion devices result in the impurity production and the formation of films of redeposited material, debris and dust. In present day devices, with short pulses, the mobile dust does not pose any serious operational problems, but it is a matter of serious concern for ITER and for later power producing devices with a high duty cycle. We report results of a dust collection experiment carried out at the T2R reversed field pinch device and related heavy impurity flux measurements. Dust and impurities were collected on passive Si surface probes and on ultralow density silica aerogel collectors. The advantage of the latter method is the possibility of nondestructive capture of the micron- and submicron-sized dust particles. The toroidal and radial deposition fluxes of dust particles and impurities are estimated and discussed in the light of the dominant forces acting on the dust.
|
|
| 2. |
|
|
| 3. |
- Halleröd, Jenny, 1987, et al.
(författare)
-
Development of the Chalmers grouped actinide extraction process
- 2015
-
Ingår i: Nukleonika. - : Walter de Gruyter GmbH. - 1508-5791 .- 0029-5922. ; 60:4, s. 829-835
-
Tidskriftsartikel (refereegranskat)abstract
- Several solvents for Grouped ActiNide EXtraction (GANEX) processes have been investigated at Chalmers University of Technology in recent years. Four different GANEX solvents; cyclo-GANEX (CyMe4--BTBP, 30 vol.% tri-butyl phosphate (TBP) and cyclohexanone), DEHBA-GANEX (CyMe4-BTBP, 20 vol.% N,N-di-2(ethylhexyl) butyramide (DEHBA) and cyclohexanone), hexanol-GANEX (CyMe4-BTBP, 30 vol.% TBP and hexanol) and FS-13-GANEX (CyMe4-BTBP, 30 vol.% TBP and phenyl trifluoromethyl sulfone (FS-13)) have been studied and the results are discussed and compared in this work. The cyclohexanone based solvents show fast and high extraction of the actinides but a somewhat poor diluent stability in contact with the acidic aqueous phase. FS-13-GANEX display high separation factors between the actinides and lanthanides and a good radiolytic and hydrolytic stability. However, the distribution ratios of the actinides are lower, compared to the cyclohexanone based solvents. The hexanol-GANEX is a cheap solvent system using a rather stable diluent but the actinide extraction is, however, comparatively low.
|
|
| 4. |
- Kazakov, Yevgen, 1984
(författare)
-
Progress in theoretical models of the ICRF mode conversion
- 2011
-
Ingår i: Nukleonika. - 1508-5791 .- 0029-5922. ; 57:1, s. 31-35
-
Tidskriftsartikel (refereegranskat)abstract
- The technique of heating the plasma with the electromagnetic waves in the ion cyclotron range of frequencies (ICRF) has many important applications that may lead to improved performance of tokamaks. Recently the heating efficiency of the ICRF mode conversion scenarios characterized by a narrow power deposition profiles received much attention. This paper highlights progress in the theoretical models of the ICRF mode conversion that allowed to achieve a successful experimental realisation of these scenarios in present-day tokamaks.
|
|
| 5. |
- Kononenko, Zhanna, 1984, et al.
(författare)
-
Test particle modelling of ion collisional transport in tokamaks
- 2011
-
Ingår i: Nukleonika. - 1508-5791 .- 0029-5922. ; 57:1, s. 43-47
-
Tidskriftsartikel (refereegranskat)abstract
- A numerical method is presented for evaluation of the radial diffusion coefficient, based on the full orbitmodelling of particle orbits in the tokamak geometry. The code solves the full orbit equations of motion for a set of test particles in an arbitrary equilibrium magnetic field. The effect of Coulomb collisions of test ions with background plasma particles is simulated by means of an equivalent Monte Carlo collision operator which scatters the pitch angle as well as the gyrophase of the particle. The radial diffusion coefficient is estimated by calculating the temporal dependence of the mean-square displacement of an ensemble of monoenergetic test particles. As an illustration of the method theeffect of magnetic islands on the impurity collisional transport is studied. It is shown that in presence of m = 2, n = 1 resonant magnetic perturbation (RMP) the diffusion coefficient for the tungsten ions (W28+, E = 1 keV) can increase by a factor of 5–10.
|
|
| 6. |
- Maletka, Krzysztof, et al.
(författare)
-
Crystalline structures of Rb2UBr6 ionic conductor determined by neutron diffraction
- 2020
-
Ingår i: Nukleonika. - : INST NUCLEAR CHEMISTRY TECHNOLOGY. - 0029-5922 .- 1508-5791. ; 65:1, s. 3-11
-
Tidskriftsartikel (refereegranskat)abstract
- The neutron powder diffraction technique has been used for structural studies of Rb2UBr6 solid electrolyte as a function of temperature. The low-, room-, and high-temperature structures have been determined. At the temperature range of 4.2-80 K, the compound crystallizes in a monoclinic unit cell in the P21/c space group. At 80 K and 853 K, the compound crystallizes in a tetragonal unit cell in the P4/mnc space group. At 300 K, the lattice constants are a = b = 7.745(1) and c = 11.064(1) (a) over bar. At the temperature range of 853-960 K, a trigonal phase is observed in the P (3) over bar ml space group.
|
|
| 7. |
- Ratynskaia, Svetlana
(författare)
-
Dusty plasmas vs. multicomponent plasmas
- 2012
-
Ingår i: Nukleonika. - 0029-5922 .- 1508-5791. ; 57:2, s. 307-312
-
Tidskriftsartikel (refereegranskat)abstract
- Different approaches employed for dusty plasmas, ranging from single particle description (valid for low dust densities) to models appropriate in the presence of dense dusty clouds, are briefly reviewed. For environments with high dust density, a selection of examples is provided to elucidate phenomena arising in dusty plasmas when the effects of absorption of plasma particles on the dust surfaces and dust charge fluctuations are of importance and cannot be neglected.
|
|
| 8. |
- Schmidt, H., et al.
(författare)
-
Gamma radiolytic stability of CyMe4BTBP and the effect of nitric acid
- 2015
-
Ingår i: Nukleonika. - : Walter de Gruyter GmbH. - 1508-5791 .- 0029-5922. ; 60:4, s. 879-884
-
Tidskriftsartikel (refereegranskat)abstract
- The highly selective nitrogen donor ligand CyMe4BTBP for An(III) separation by solvent extraction was irradiated in a 60Co γ-source under varying conditions. Organic solutions of 10 mmol/L ligand in 1-octanol were contacted with different concentrations of nitric acid to observe the influence of an aqueous phase during irradiation. In subsequent liquid-liquid extraction experiments, distribution ratios of 241Am and 152Eu were determined. Distribution ratios decreased with increasing absorbed dose when irradiation was performed in the absence of nitric acid. With addition of nitric acid, initial distribution ratios remained constant over the whole examined dose range up to 300 kGy. For qualitative determination of radiolysis products, HPLC-MS measurements were performed. The protective effect of nitric acid was confirmed, since in samples irradiated with acid contact, no degradation products were observed, but only addition products of the 1-octanol molecule to the CyMe4BTBP molecule.
|
|
| 9. |
- Csanad, M, et al.
(författare)
-
A hint at quark deconfinement in 200 GeVAu+Au data at RHIC
- 2004
-
Ingår i: Nukleonika. - 0029-5922. ; 49, s. 49-55
-
Tidskriftsartikel (refereegranskat)abstract
- We give the emission function of the axially symmetric Buda-Lund hydro, model and present its simultaneous, high quality fits to identified particle spectra, two-particle Bose-Einstein or HBT correlations and charged particle pseudorapidity distributions as measured by BRAHMS and PHENIX in 0-30% central, roots(NN) = 200 GeV Au+Au collisions at RHIC. The best fit is achieved when the most central region of the particle emitting volume is superheated to T-0 = 200 +/- 9 MeV greater than or equal to T-c = 172 +/- 3 MeV, a 3 sigma effect.
|
|
| 10. |
- Csanad, M, et al.
(författare)
-
Buda-Lund hydro model and the elliptic flow at RHIC
- 2004
-
Ingår i: Nukleonika. - 0029-5922. ; 49:Supplement 2, s. 45-48
-
Tidskriftsartikel (refereegranskat)abstract
- The ellipsoidally symmetric Buda-Lund hydrodynamic model describes naturally the transverse momentum and the pseudorapidity dependence of the elliptic flow in Au+Au collisions at roots(NN) = 130 and 200 GeV. The result confirms the indication of quark deconfinement in Au+Au collisions at RHIC, obtained from Buda-Lund hydro model fits to combined spectra and HBT radii of BRAHMS, PHOBOS, PHENIX and STAR.
|
|
