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  • 1. Cherigier-Kovacic, L.
    et al.
    Ström, Petter
    KTH, Fusionsplasmafysik.
    Lejeune, A.
    Doveil, F.
    Electric field induced Lyman-alpha emission of a hydrogen beam for electric field measurements2015In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 86, no 6, article id 063504Article in journal (Refereed)
    Abstract [en]

    Electric field induced Lyman-alpha emission is a new way of measuring weak electric fields in vacuum and in a plasma. It is based on the emission of Lyman-alpha radiation (121.6 nm) by a low-energy metastable H atom beam due to Stark-quenching of the 2s level induced by the field. In this paper, we describe the technique in detail. Test measurements have been performed in vacuum between two plates polarized at a controlled voltage. The intensity of emitted radiation, proportional to the square of the field modulus, has been recorded by a lock-in technique, which gives an excellent signal to noise ratio. These measurements provide an in situ calibration that can be used to obtain the absolute value of the electric field. A diagnostic of this type can help to address a long standing challenge in plasma physics, namely, the problem of measuring electric fields without disturbing the equilibrium of the system that is being studied.

  • 2. Chérigier-Kovacic, L.
    et al.
    Ström, Petter
    KTH, Fusionsplasmafysik.
    Doveil, F.
    Electric field induced lyman-α Emission (EFILE) diagnostic for electric field measurements2015In: Proceedings of Science, Proceedings of Science (PoS) , 2015Conference paper (Refereed)
    Abstract [en]

    When a metastable hydrogen test beam is exposed to a constant or oscillating electric field, Lyman-A (121.6 nm) emission occurs. This results from the Stark quenching of the metastable 2s level, induced by the field. The intensity of the radiation is proportional to the square of the electric field amplitude and it is recorded by a lock-in technique, which gives an excellent signal to noise ratio. This provides us with a very sensitive and non intrusive method to measure the electric field value, called EFILE (Electric Field Induced Lyman-A emission). Sensitivity is as good as 0.1 V/cm in the case of an oscillatory field resonant with the Lamb shift frequency ≈ 1 GHz. Hydrogen ions are produced in a magnetic multicusp source by a thermo-electronic discharge. The ions are extracted from the source, focused by a series of electrostatic lenses and accelerated to 500 eV. The beam interacts with cesium vapor which produces atoms in the metastable 2s1=2 state. In the diagnosed volume, the beam passes between a pair of plane electrodes separated by 5 cm. One of them is grounded, the other one is polarized to generate an electric field. The diagnosed volume can be kept under vacuum or exposed to an argon plasma. Lyman-A emission from the beam passing between the plates is measured as a function of the polarized plate voltage. A saturation of the signal is observed at large field amplitudes, which is explained through oscillatory and geometrical mechanisms. A function that takes this saturation into account is used as a calibration for the subsequent electric field profile measurements in the case of a constant voltage applied between the plates in vacuum. We find a good agreement between our results and a finite element method calculation of the profile.

  • 3. Doveil, F.
    et al.
    Cherigier-Kovacic, L.
    Ström, Petter
    KTH, Fusionsplasmafysik.
    Lamb-shift and electric field measurements in plasmas2017In: Plasma Physics and Controlled Fusion, ISSN 0741-3335, E-ISSN 1361-6587, Vol. 59, no 1, article id 014020Article in journal (Refereed)
    Abstract [en]

    The electric field is a quantity of particular relevance in plasma physics. Indeed, its fluctuations are responsible for different macroscopic phenomena such as anomalous transport in fusion plasmas. Answering a long-standing challenge, we offer a new method to locally and non-intrusively measure weak electric fields and their fluctuations in plasmas, by means of a beam of hydrogen ions or atoms. We present measurements of the electric field in vacuum and in a plasma where Debye shielding is measured. For the first time, we have used the Lamb-shift resonance to measure oscillating electric fields around 1 GHz and observed the strong enhancement of the Lyman-alpha signal. The measurement is both direct and non-intrusive. This method provides sensitivity (mV cm(-1)) and temporal resolution (ns) that are three orders higher compared to current diagnostics. It thus allows measuring fluctuations of the electric field at scales not previously reached experimentally.

  • 4. Fortuna-Zalesna, E.
    et al.
    Weckmann, Armin
    KTH, Fusionsplasmafysik.
    Grozonka, J.
    Rubel, Marek
    KTH, Fusionsplasmafysik.
    Esser, H. G.
    Freisinger, M.
    Kreter, A.
    Kischner, A.
    Sergienko, G.
    Ström, Petter
    KTH, Fusionsplasmafysik.
    Dust Survey Following the Final Shutdown of TEXTOR: Metal Particles and Fuel Retention2016In: Physica Scripta, ISSN 0031-8949, E-ISSN 1402-4896, Vol. T167, article id 014059Article in journal (Refereed)
    Abstract [en]

    The work presents results of a broad TEXTOR dust survey in terms of its composition, structure, distribution and fuel content. The dust particles were collected after final shutdown of TEXTOR in December 2013. Fuel retention, as determined by thermal desorption, varied significantly, even by two orders of magnitude, dependent on the dust location in the machine. Dust structure was examined by means of scanning electron microscopy combined with energy-dispersive X-ray spectroscopy, focused ion beam and scanning transmission electron microscopy. Several categories of dust have been identified. Carbon-based stratified and granular deposits were dominating, but the emphasis in studies was on metal dust. They were found in the form of small particles, small spheres, flakes and splashes which formed “comet”-like structures clearly indicating directional effects in the impact on surfaces of plasma-facing components. Nickel-rich alloys from the Inconel liner and iron-based ones from various diagnostic holders were the main components of metal-containing dust, but also molybdenum and tungsten debris were detected. Their origin is discussed.

  • 5.
    Gupta, Rahul
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Behera, Nilamani
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Venugopal, Vijay A.
    Seagate Technology, 1 Disc Drive, Springtown, Northern Ireland, BT48 0BF, United Kingdom.
    Basu, Swaraj
    Seagate Technology, 1 Disc Drive, Springtown, Northern Ireland, BT48 0BF, United Kingdom.
    Puri, Anil K.
    Seagate Technology, 1 Disc Drive, Springtown, Northern Ireland, BT48 0BF, United Kingdom.
    Ström, Petter
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Gubbins, Mark A.
    Seagate Technology, 1 Disc Drive, Springtown, Northern Ireland, BT48 0BF, United Kingdom.
    Bergqvist, Lars
    Department of Applied Physics, School of Engineering Sciences, KTH Royal Institute of Technology, Electrum 229, SE-16440 Kista, Sweden;Swedish e-Science Research Center, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden.
    Brucas, Rimantas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Svedlindh, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Kumar, Ankit
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Engineering of spin mixing conductance at Ru/FeCo/Ru interfaces: Effect of Re doping2020In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 101, no 2, article id 024401Article in journal (Refereed)
    Abstract [en]

    We have deposited polycrystalline Re-doped (Fe65Co35)(100-x)Rex (0 ≤ x ≤ 12.6 at. %) thin films grown under identical conditions and sandwiched between thin layers of Ru in order to study the phenomenon of spin pumping as a function of Re concentration. In-plane and out-of-plane ferromagnetic resonance spectroscopy results show an enhancement of the Gilbert damping with an increase in Re doping. We find 98% enhancement in the real part of effective spin mixing conductance [Re(g↑↓eff)] with Re doping. Conversely, the Re(g↑↓eff) does not change with Re doping in Fe65Co35 thin films which are seeded and capped with Cu layers. The enhancement in Re(g↑↓eff) of Re-doped Fe65Co35 thin films sandwiched between thin layers of Ru is linked to the Re doping-induced change of the interface electronic structure in the nonmagnetic Ru layer. The saturation magnetization decreases 35% with increasing Re doping up to 12.6 at. %. This study opens a direction of tuning the spin mixing conductance in magnetic heterostructures by doping of the ferromagnetic layer, which is essential for the realization of energyefficient operation of spintronic devices.

  • 6. Huber, A.
    et al.
    Brezinsek, S.
    Kirschner, A.
    Ström, Petter
    KTH, Fusionsplasmafysik.
    Sergienko, G.
    Huber, V.
    Borodkina, I.
    Douai, D.
    Jachmich, S.
    Linsmeier, Ch.
    Lomanowski, B.
    Matthews, G.F
    Mertens, P.h
    Determination of tungsten sources in the JET-ILW divertor by spectroscopic imaging in the presence of a strong plasma continuum2019In: Nuclear Materials and Energy, E-ISSN 2352-1791, Vol. 18, p. 118-124Article in journal (Refereed)
    Abstract [en]

    The identification of the sources of atomic tungsten and the measurement of their radiation distribution in front of all plasma-facing components has been performed in JET with the help of two digital cameras with the same two-dimensional view, equipped with interference filters of different bandwidths centred on the W I (400.88 nm) emission line. A new algorithm for the subtraction of the continuum radiation was successfully developed and is now used to evaluate the W erosion even in the inner divertor region where the strong recombination emission is dominating over the tungsten emission. Analysis of W sputtering and W redistribution in the divertor by video imaging spectroscopy with high spatial resolution for three different magnetic configurations was performed. A strong variation of the emission of the neutral tungsten in toroidal direction and corresponding W erosion has been observed. It correlates strongly with the wetted area with a maximal W erosion at the edge of the divertor tile.

  • 7. Koslowski, H.R.
    et al.
    Bhattacharyya, S.R.
    Hansen, P.
    Linsmeier, Ch.
    Rasinski, M.
    Ström, Petter
    KTH, Fusionsplasmafysik.
    Temperature-dependent in-situ LEIS measurement of W surface enrichment by 250 eV D sputtering of EUROFER2018In: Nuclear Materials and Energy, E-ISSN 2352-1791, Vol. 16, p. 181-190Article in journal (Refereed)
  • 8.
    Rubel, Marek
    et al.
    KTH, Fusionsplasmafysik.
    Weckmann, Armin
    KTH, Fusionsplasmafysik.
    Ström, Petter
    KTH, Fusionsplasmafysik.
    Petersson, Per
    KTH, Fusionsplasmafysik.
    Garcia Carrasco, Alvaro
    KTH, Fusionsplasmafysik.
    Brezinsek, S.
    Coenen, J.
    Kreter, A.
    Moeller, S.
    Wienhold, P.
    Wauters, T.
    Fortuna-Zalesna, E.
    Tracer techniques for the assessment of material migration and surface modification of plasma-facing components2015In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 463, p. 280-284Article in journal (Refereed)
    Abstract [en]

    Tracer techniques were used in the TEXTOR tokamak to determine high-Z metal migration and the deposition of species used for plasma edge cooling or wall conditioning under different types of operation conditions. Volatile molybdenum hexa-fluoride, nitrogen-15 and oxygen-18 were used as markers in tokamak or ion cyclotron wall conditioning discharges (ICWC). The objective was to obtain qualitative and quantitative of a global and local deposition pattern and material mixing effects. The deposition and retention was studied on plasma-facing components, collector probes and test limiters. Optical spectroscopy and ex-situ analysis techniques were used to determine the plasma response to tracer injection and the modification of surface composition. Molybdenum and light isotopes were detected on all types of limiters and short-term probes retrieved from the vessel showing that both helium and nitrogen are trapped following wall conditioning and edge cooling. Only small amounts below 1 x 10(19) m(-2) of O-18 were detected on surfaces treated by oxygen-assisted ICWC.

  • 9.
    Skini, Ridha
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Ghorai, Sagar
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Ström, Petter
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Ivanov, Sergey
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics. Karpov Institute of Physical Chemistry, RU-103064 K-64, Moscow, Russia.
    Primetzhofer, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Svedlindh, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Large room temperature relative cooling power in La0.5Pr0.2Ca0.1Sr0.2MnO32020In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 827, article id 154292Article in journal (Refereed)
    Abstract [en]

    The La0.5Pr0.2Ca0.1Sr0.2MnO3 compound has been investigated as a potential candidate for room temperature magnetocaloric refrigeration. The Rietveld refinement of X-ray powder diffraction patterns confirms that the compound crystalizes in an orthorhombic phase with the Pnma space group. Rutherford backscattering spectrometry and time-of-flight elastic recoil detection analysis, verified the desired ratio of the elements in the compound. Using X-ray photoelectron spectroscopy two oxidation states of manganese (Mn), Mn4+ and Mn3+ were identified in the compound with relative amounts of 32% and 68%, respectively. The observed spin orbit splitting of the Mn-2p3/2 and Mn-2p1/2 levels was obtained as 11.7 eV. A ferromagnetic to paramagnetic transition was observed around 296 K, which makes the material interesting for magnetic cooling near room temperature. In addition, the absence of magnetic hysteresis provides another argument in favor of the studied compound. The isothermal entropy change (-deltaSm) and the relative cooling power (RCP) for a magnetic field change of 5 T were found to be 4 J/kg K and 372 J/kg, respectively. From the comparison of the values of (-deltaSm) and RCP with those obtained for the archetypal magnetocaloric material gadolinium, it is argued that our material can be considered as a potential candidate in cooling systems based on magnetic refrigeration.

  • 10.
    Ström, Petter
    Kungliga tekniska högskolan - KTH, Fusionsplasmafysik.
    Material characterization for magnetically confined fusion: Surface analysis and method development2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The dream of abundant clean energy has brought scientists and laypeople alike to ponder the possibilities of nuclear fusion since it was established as the energy source of the stars in 1939. Starting from the mid the 20th century, significant effort has been put into overcoming the technological challenges related to the construction of a power plant, but initial optimism has faded somewhat due to a notable absence of practical outcomes. Nevertheless, the research continues and progress is made slowly but surely.

    The present work deals with a small part of the fusion puzzle, namely the materials to be used in the first wall surrounding a magnetically confined plasma. Carbon, which has historically been considered as the most viable element for this role, has been ruled out due to issues with plasma-induced erosion, hydrocarbon formation and a buildup of thick deposited material layers on wall components. The latter two lead to an unacceptable accumulation of radioactive tritium, both in the deposited layers and in dust particles. A metal wall, which would alleviate these particular problems but increase the severity of others, is therefore envisioned for a future demonstration reactor.

    Three contributions to the overall research effort are made though this thesis. First, an increased understanding of plasma-induced erosion of so-called reduced activation ferritic-martensitic steels and preferential sputtering of light material components is provided. High-resolution ion beam analysis and microscopy methods are used to examine samples of such a steel after exposure to plasma under controlled circumstances. Model films consisting of a mixture of iron and tungsten deposited on silicon substrates are also studied as they constitute simpler systems where the effects of interest may be simulated. The knowledge obtained is necessary for an assessment of the possibility to use reduced activation steel as a plasma-facing material in specific regions of a reactor wall.

    The second contribution consists of reports on the composition of deposited material layers on wall components retrieved from the plasma confinement experiments JET and TEXTOR. These provide limited conclusions on the range and rate of material erosion, transport and deposition in two cases.

    Finally, a detection system for the ion beam technique elastic recoil detection analysis has been assembled, tested and put into operation. In addition to improving the quality of analyses performed on fusion-related materials, the system has become an established tool available for users of the 5 MV electrostatic pelletron accelerator at Uppsala University’s Tandem Laboratory.

  • 11.
    Ström, Petter
    et al.
    KTH, Fusionsplasmafysik.
    Petersson, Per
    KTH, Fusionsplasmafysik.
    Rubel, Marek
    KTH, Fusionsplasmafysik.
    Possnert, Goran
    Uppsala Univ, Dept Phys & Astron, Tandem Lab, Box 529, SE-75120 Uppsala, Sweden..
    Erratum: "A combined segmented anode gas ionization chamber and time-of-flight detector for heavy ion elastic recoil detection analysis" [Rev. Sci. Instrum. 87, 103303 (2016)]2018In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 89, no 4, article id 049901Article in journal (Refereed)
  • 12.
    Ström, Petter
    et al.
    KTH, Fusionsplasmafysik.
    Petersson, Per
    KTH, Fusionsplasmafysik.
    Rubel, Marek
    KTH, Fusionsplasmafysik.
    Weckmann, Armin
    KTH, Fusionsplasmafysik.
    Brezinsek, S.
    Kreter, A.
    Möller, S.
    Rozniatowski, K.
    Characterisation of surface layers formed on plasma-facing components in controlled fusion devices: Role of heavy ion elastic recoil detection2015In: Vacuum, ISSN 0042-207X, E-ISSN 1879-2715, Vol. 122, p. 260-267Article in journal (Refereed)
    Abstract [en]

    Wall components retrieved from the TEXTOR tokamak after tracer experiments with nitrogen-15 and molybdenum hexafluoride (MoF6) injection were studied to determine deposition patterns and, by this, to conclude on material migration. Toroidal limiter tiles made of carbon fibre composites and fine grain graphite were examined using time-of-flight heavy ion elastic recoil detection analysis. Molybdenum deposition patterns indicated migration based on erosion and prompt re-deposition. Nitrogen-15 was trapped together with the deposited molybdenum. Some information on the depth distribution of species in the top 400 nm layer of the limiters was obtained; however surface roughness of the samples strongly limited resolution. In the case of molybdenum, the largest concentration was found in the 100 nm outermost layer, whereas fluorine and nitrogen-15 displayed more irregular profiles. Other species, besides deuterium fuel and carbon-12, were also identified: boron-10 and boron-11 originating from boronisations, carbon-13 from earlier tracer experiments, nitrogen-14 from plasma edge cooling and metals eroded from the Inconel wall.

  • 13.
    Ström, Petter
    et al.
    KTH Royal Inst Technol, Sch Elect Engn, Dept Fus Plasma Phys, SE-10044 Stockholm, Sweden..
    Primetzhofer, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Schwarz-Selinger, Thomas
    Max Planck Inst Plasma Phys, D-85748 Garching, Germany..
    Sugiyama, Kazuyoshi
    Max Planck Inst Plasma Phys, D-85748 Garching, Germany..
    Compositional and morphological analysis of FeW films modified by sputtering and heating2017In: NUCLEAR MATERIALS AND ENERGY, ISSN 2352-1791, Vol. 12, p. 472-477Article in journal (Refereed)
    Abstract [en]

    Surface compositional changes of iron- tungsten films by deuterium (D) ion bombardment were studied by means of medium energy ion scattering, elastic recoil detection analysis and Rutherford backscattering spectrometry. The energy of the bombarding ions was 200 eV/D and the fluence was varied from 10(21) D/m(2) to 10 24 D/m(2). A significant increase of the tungsten concentration within the 20 nm closest to the sample surface, caused by preferential sputtering of iron, was seen for the films exposed 10(23) D/m(2) or more. In the sample exposed to the highest fluence, 10(24) D/m(2), the concentration of tungsten was increased from an initial 1.7 at. % up to approximately 24 at. % averaged over the 5 nm closest to the surface. The analysis was complicated by the presence of oxygen on the sample surfaces. In order to study the thermal stability of the tungsten enriched layer, the sample initially exposed to 10(23) D/m(2) at room temperature was heated to 400 degrees C in the measurement chamber for medium energy ion scattering and several spectra were recorded at intermediate temperatures. The obtained data showed that the layer was relatively stable below 200 degrees C whereas a drastic change in the film composition occurred between 200 degrees C and 250 degrees C due to interdiffusion of iron and silicon, the latter of which was the substrate material. The surface morphologies of the films were probed with atomic force microscopy showing that protrusions of 10-100 nm width appeared after deuterium bombardment at fluences higher than 10(22) D/m(2).

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  • 14.
    Weckmann, Armin
    et al.
    KTH, Fusionsplasmafysik.
    Petersson, Per
    KTH, Fusionsplasmafysik.
    Rubel, Marek
    KTH, Fusionsplasmafysik.
    Ström, Petter
    KTH, Fusionsplasmafysik.
    Kurki-Suonio, T.
    Aalto Univ, Dept Appl Phys, Aalto 00076, Finland..
    Sarkimaki, K.
    Aalto Univ, Dept Appl Phys, Aalto 00076, Finland..
    Kirschner, A.
    Forschungszentrum Julich, Inst Energie & Klimaforsch Plasmaphys, D-52425 Julich, Germany..
    Kreter, A.
    Forschungszentrum Julich, Inst Energie & Klimaforsch Plasmaphys, D-52425 Julich, Germany..
    Brezinsek, S.
    Forschungszentrum Julich, Inst Energie & Klimaforsch Plasmaphys, D-52425 Julich, Germany..
    Romazanov, J.
    Forschungszentrum Julich, Inst Energie & Klimaforsch Plasmaphys, D-52425 Julich, Germany..
    Wienhold, P.
    Forschungszentrum Julich, Inst Energie & Klimaforsch Plasmaphys, D-52425 Julich, Germany..
    Pospieszczyk, A.
    Forschungszentrum Julich, Inst Energie & Klimaforsch Plasmaphys, D-52425 Julich, Germany..
    Hakola, A.
    VTT Tech Res Ctr Finland Ltd, Espoo 02044, Finland..
    Airila, M.
    VTT Tech Res Ctr Finland Ltd, Espoo 02044, Finland..
    Review on global migration, fuel retention and modelling after TEXTOR decommission2018In: NUCLEAR MATERIALS AND ENERGY, Vol. 17, p. 83-112Article, review/survey (Refereed)
    Abstract [en]

    Before decommissioning of the TEXTOR tokamak in 2013, the machine was conditioned with a comprehensive migration experiment where MoF6 and N-15(2) were injected on the very last operation day. Thereafter, all plasmafacing components (PFCs) were available for extensive studies of both local and global migration of impurities - Mo, W, Inconel alloy constituents, 15 N, F - and fuel retention studies. Measurements were performed on 140 limiter tiles out of 864 throughout the whole machine to map global transport. One fifth of the introduced molybdenum could be found. Wherever possible, the findings are compared to results obtained previously in other machines. This review incorporates both published and unpublished results from this TEXTOR study and combines findings with analytical methods as well as modelling results from two codes, ERO and ASCOT. The main findings are: Both local and global molybdenum transport can be explained by toroidal plasma flow and (sic) x (sic) drift. The suggested transport scheme for molybdenum holds also for other analysed species, namely tungsten from previous experiments and medium-Z metals (Cr-Cu) introduced on various occasions. Analytical interpretation of several deposition profile features is possible with basic geometrical and plasma physics considerations. These are deposition profiles on the collector probe, the lower part of the inner bumper limiter, the poloidal cross-section of the inner bumper limiter, and the poloidal limiter. Any deposition pattern found in this TEXTOR study, including fuel retention, has neither poloidal nor toroidal symmetry, which is often assumed when determining deposition profiles on global scale. Fuel retention is highly inhomogeneous due to local variation of plasma parameters - by auxiliary heating systems and impurity injection - and PFC temperature. Local modelling with ERO yields good qualitative agreement but too high local deposition efficiency. Global modelling with ASCOT shows that the radial electric field and source form have a high impact on global deposition patterns, while toroidal flow has little influence. Some of the experimental findings could be reproduced. Still, qualitative differences between simulated and experimental global deposition patterns remain. The review closes with lessons learnt during this extensive TEXTOR study which might be helpful for future scientific exploitation of other tokamaks to be decommissioned.

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