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Petersson, Per
Publications (10 of 12) Show all publications
Pegourie, B., Panayotis, S., Languille, P., Martin, C., Dittmar, T., Gauthier, E., . . . Vavpetic, P. (2013). Deuterium inventory in Tore Supra: Coupled carbon-deuterium balance. Paper presented at 20th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices (PSI), MAY 21-25, 2012, Aachen, GERMANY. Journal of Nuclear Materials, 438, S120-S125
Open this publication in new window or tab >>Deuterium inventory in Tore Supra: Coupled carbon-deuterium balance
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2013 (English)In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 438, p. S120-S125Article in journal (Refereed) Published
Abstract [en]

This paper presents an analysis of the carbon-deuterium circulation and the resulting balance in Tore Supra over the period 2002-2007. Carbon balance combines the estimation of carbon gross erosion from spectroscopy, net erosion and deposition using confocal microscopy, lock-in thermography and SEM, and a measure of the amount of deposits collected in the vacuum chamber. Fuel retention is determined from post-mortem (PM) analyses and gas balance (GB) measurements. Special attention was paid to the deuterium outgassed during the nights and weekends of the experimental campaign (vessel under vacuum, Plasma Facing Components at 120 degrees C) and during vents (vessel at atmospheric pressure, PFCs at room temperature). It is shown that this outgassing is the main process reconciling the PM and GB estimations of fuel retention, closing the coupled carbon-deuterium balance. In particular, it explains why the deuterium concentration in deposits decreases with increasing depth. (C) 2013 Elsevier B.V. All rights reserved.

National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-220563 (URN)10.1016/j.jnucmat.2013.01.019 (DOI)000330795300019 ()
Conference
20th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices (PSI), MAY 21-25, 2012, Aachen, GERMANY
Available from: 2014-03-20 Created: 2014-03-17 Last updated: 2017-12-05Bibliographically approved
Petersson, P., Possnert, G., Rubel, M., Dittmar, T., Pégouiré, B., Tsitrone, E. & Wessel, E. (2011). An Overview of Nuclear Micro beam Analysis of Surface and Bulk Fuel Retention in Carbon-Fibre Composites from Tore Supra. Journal of Nuclear Materials, 451(1), s764-s764
Open this publication in new window or tab >>An Overview of Nuclear Micro beam Analysis of Surface and Bulk Fuel Retention in Carbon-Fibre Composites from Tore Supra
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2011 (English)In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 451, no 1, p. s764-s764Article in journal (Refereed) Published
Abstract [en]

Surface and bulk retention of deuterium in tiles of the pump limiter from Tore Supra was examined with nuclear reaction analysis using both standard and micro-beam techniques. The aim was to determine the variations in the content and distribution of fuel species in carbon-fibre composites. On plasma-facing surfaces from the deposition zone, the D content reaches 2.5 × 1019 cm−2 in about 8 μm thick top layer, but lateral differences reach even more than one order of magnitude. This is also measured in the erosion zone: 6.6 × 1017 cm−2 to 7.7 × 1018 cm−2 D atoms. Bulk content was examined on cross-sections opened by fracturing the tiles. Fuel is detected up to the depth of 1–1.5 mm beneath the plasma-facing surface in tiles from both the erosion and deposition zones. It occurs in bands, about 100 μm wide and several mm long, roughly parallel to the original plasma-facing surface.

National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-128873 (URN)10.1016/j.jnucmat.2010.10.044 (DOI)000298128100173 ()
Available from: 2010-07-29 Created: 2010-07-29 Last updated: 2017-12-12Bibliographically approved
Petersson, P., Bergsåker, H., Possnert, G., Coad, J. P., Likonen, J., Koivuranta, S. & Hakola, A. (2011). Cross sections of deposited layers investigated by micronuclear reaction analysis. Journal of Nuclear Materials, 415(1), S262-S265
Open this publication in new window or tab >>Cross sections of deposited layers investigated by micronuclear reaction analysis
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2011 (English)In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 415, no 1, p. S262-S265Article in journal (Refereed) Published
Abstract [en]

Cross sections of deposited layers from the divertor of the Joint European Torus (JET) have been investigated, microscopically and by ion microbeam analysis. The thickness of these layers on the studied samples varies between about 50 mu m and 800 mu m depending on the exposure time and poloidal location of the sample. For most of the thicker layers a laminar structure is observed. In some locations changes, such as gaps, are also observed along the laminar structure as well as more complex structures. The possibility to use the layers as historical reference was also investigated.

National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-169632 (URN)10.1016/j.jnucmat.2010.11.058 (DOI)000298128100058 ()
Available from: 2012-03-05 Created: 2012-03-05 Last updated: 2017-12-07Bibliographically approved
Porro, S., De Temmerman, G., Lisgo, S., Rudakov, D. L., Litnovsky, A., Petersson, P., . . . Wilson, J. I. (2011). Diamond coatings exposure to fusion-relevant plasma conditions. Journal of Nuclear Materials, 415(1), S161-S164
Open this publication in new window or tab >>Diamond coatings exposure to fusion-relevant plasma conditions
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2011 (English)In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 415, no 1, p. S161-S164Article in journal (Refereed) Published
Abstract [en]

Several types of diamond layers have been deposited on molybdenum tiles by chemical vapour deposition techniques, and exposed under erosion-dominated conditions in the SOL of TEXTOR in order to assess them as a suitable candidate for plasma-facing material. Post-exposure characterisation of physical properties and surface modification induced by the plasma was performed by SEM imaging, investigation of diamond surface by micro-Raman spectroscopy and deuterium retention measurements by NRA. The analyses evidenced that lightly boron-doped micro-crystalline diamond is performing better than undoped and heavily doped samples, and nano-crystalline diamond and diamond-like carbon, as it showed lower surface modification, lower presence of arcing traces at the surface and lower deuterium retention. High concentration of boron in the layers led to higher retention of deuterium, whereas undoped (insulating) diamond showed increased arcing activity. Nano-crystalline diamond and diamond-like carbon layers generally showed poorer mechanical properties.

National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-169630 (URN)10.1016/j.jnucmat.2010.10.005 (DOI)000298128100035 ()
Available from: 2012-03-05 Created: 2012-03-05 Last updated: 2017-12-07Bibliographically approved
Ivanova, D., Rubel, M., Philipps, V., Schweer, B., Petersson, P., Freisinger, M. & Schmidt, A. (2011). Fuel re-absorption by thermally treated co-deposited carbon layers. Physica Scripta (T145), 014006
Open this publication in new window or tab >>Fuel re-absorption by thermally treated co-deposited carbon layers
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2011 (English)In: Physica Scripta, ISSN 0031-8949, E-ISSN 1402-4896, no T145, p. 014006-Article in journal (Refereed) Published
Abstract [en]

Systematic studies have been conducted to address the fuel re-absorption by carbon deposits under repeated exposure to plasma after cleaning procedures. The investigation was done with graphite tiles from ALT-II (Advanced Limiter Test II), i.e. the main limiter at the TEXTOR tokamak. Pure graphite plates were used as the reference material. The experimental programme comprised the following: pre-characterization of specimens; D desorption by baking the tile at 1273 K; surface analyses of the fuel-depleted layers; exposure to deuterium in a laboratory plasma device and in TEXTOR; and quantitative assessment of deuterium re-absorption. The main result is that fuel retention in the re-exposed deposits is 30-40 times lower than that in the original co-deposit, showing that fuel re-absorption does not lead to an immediate re-saturation of deposits. Annealing at high temperatures enhances layer brittleness, leading eventually to detachment of co-deposits.

National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-167922 (URN)10.1088/0031-8949/2011/T145/014006 (DOI)000298475200007 ()
Available from: 2012-02-02 Created: 2012-02-02 Last updated: 2017-12-08Bibliographically approved
Ivanova, D., Rubel, M., Philipps, V., Schweer, B., Freisinger, M., Huber, A., . . . Dittmar, T. (2011). Laser-based and thermal methods for fuel removal and cleaning of plasma-facing components. Journal of Nuclear Materials, 415(1), S801-S804
Open this publication in new window or tab >>Laser-based and thermal methods for fuel removal and cleaning of plasma-facing components
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2011 (English)In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 415, no 1, p. S801-S804Article in journal (Refereed) Published
Abstract [en]

The efficiency of two methods for in situ fuel removal has been tested on carbon and tungsten limiters retrieved from the TEXTOR and Tore Supra tokamaks: laser-induced ablation of co-deposits and annealing in vacuum at elevated temperature. The analyses of gas phase and surfaces performed with thermal desorption spectrometry, optical spectroscopy, ion beam analysis, surface profilometry and microscopy methods have shown: (i) the ablation leads to the generation of dust particles of 50 nm - 2 mu m; (ii) volatile products of ablation undergo condensation on surrounding surfaces; (iii) D/C ratio in such condensate is in the range 0.02-0.03; (iv) long-term annealing of 623 K for 70 h results in release of not more than 10% of deuterium accumulated in plasma-facing components; (v) effective removal is reached by heating to 900-1300 K.

National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-169634 (URN)10.1016/j.jnucmat.2011.01.119 (DOI)000298128100183 ()
Available from: 2012-03-05 Created: 2012-03-05 Last updated: 2017-12-07Bibliographically approved
Rubel, M., Philipps, V., Marot, L., Petersson, P., Pospieszczyk, A. & Schweer, B. (2011). Nitrogen and neon retention in plasma-facing materials. Journal of Nuclear Materials, 415(1), S223-S226
Open this publication in new window or tab >>Nitrogen and neon retention in plasma-facing materials
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2011 (English)In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 415, no 1, p. S223-S226Article in journal (Refereed) Published
Abstract [en]

Tungsten plate was exposed in the TEXTOR tokamak during nitrogen-assisted discharges. In order to determine material mixing on tungsten, the plate was examined ex situ with ion beam analysis techniques including time-of-flight heavy ion elastic recoil detection analysis and also with X-ray photoelectron spectroscopy. Nitrogen content in the range from 1.3 x 10(15) to 3.4 x 10(15) cm(-2) is measured in the outermost surface layer (20 nm) of the W plate. Photoelectron spectroscopy detects nitrogen both in the elemental and compound form, i.e. tungsten nitride (WN/W2N). Nitrogen is measured even in hot areas free from deuterium. Also neon co-implantation into the plasma-facing components has been identified following Ne-cooled pulses.

National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-169631 (URN)10.1016/j.jnucmat.2010.08.035 (DOI)000298128100049 ()
Available from: 2012-03-05 Created: 2012-03-05 Last updated: 2017-12-07Bibliographically approved
Petersson, P. (2010). Ion Beam Analysis of First Wall Materials Exposed to Plasma in Fusion Devices. (Doctoral dissertation). Uppsala: Acta Universitatis Upsaliensis
Open this publication in new window or tab >>Ion Beam Analysis of First Wall Materials Exposed to Plasma in Fusion Devices
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

One major step needed for fusion to become a reliable energy source is the development of materials for the extreme conditions (high temperature, radioactivity and erosion) caused by hot plasmas. The main goal of the present study is to use and optimise ion beam methods (lateral resolution and sensitivity) to characterise the distribution of hydrogen isotopes that act as fuel. Materials from the test reactors JET (Joint European Torus), TEXTOR (Tokamak Experiment for Technology Oriented Research) and Tore Supra have been investigated.

Deuterium, beryllium and carbon were measured by elastic recoil detection analysis (ERDA) and nuclear reaction analysis (NRA). To ensure high 3D spatial resolution a nuclear microbeam (spot size <10 µm) was used with 3He and 28Si beams. The release of hydrogen caused by the primary ion beam was monitored and accounted for.

Large variations in surface (top 10 µm) deuterium concentrations in carbon fibre composites (CFC) from Tore Supra and TEXTOR was found, pointing out the importance of small pits and local fibre structure in understanding fuel retention. At deeper depths into the CFC limiter tiles from Tore Supra, deuterium rich bands were observed confirming the correlation between the internal material structure and fuel storage in the bulk.

Sample cross sections from thick deposits on the JET divertor showed elemental distributions that were dominantly laminar although more complex structures also were observed. Depth profiles of this kind elucidate the plasma-wall interaction and material erosion/deposition processes in the reactor vessel.

The information gained in this thesis will improve the knowledge of first wall material for the next generation fusion reactors, concerning the fuel retention and the lifetime of the plasma facing materials which is important for safety as well as economical reasons.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2010. p. 61
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 752
Keywords
Ion beam analysis, Microbeam, Plasma wall interaction, Deuterium, Beryllium, Carbon fibre composites, Divertor, Nuclear reaction analysis, Helium-3
National Category
Fusion, Plasma and Space Physics
Research subject
Ion Physics
Identifiers
urn:nbn:se:uu:diva-128875 (URN)978-91-554-7846-9 (ISBN)
Public defence
2010-09-10, room 4101, Ångströmlaboratoiet, Lägerhyddsvägen 1, Uppsala, 10:00 (English)
Opponent
Supervisors
Available from: 2010-08-19 Created: 2010-07-29 Last updated: 2010-08-19
Petersson, P., Bergsåker, H., Possnert, G., Coad, J. P., Koivuranta, S. & Likonen, J. (2010). Ion beam micro analysis of deposits at tokamak divertor surfaces. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 268(11-12), 1838-1841
Open this publication in new window or tab >>Ion beam micro analysis of deposits at tokamak divertor surfaces
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2010 (English)In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, E-ISSN 1872-9584, Vol. 268, no 11-12, p. 1838-1841Article in journal (Refereed) Published
Place, publisher, year, edition, pages
Amsterdam: Elsevier, 2010
Keywords
Nuclear reaction analysis; Micro-beam; Deuterium; Beryllium
National Category
Other Engineering and Technologies not elsewhere specified
Identifiers
urn:nbn:se:uu:diva-128871 (URN)10.1016/j.nimb.2010.02.025 (DOI)000278702300032 ()
Available from: 2010-07-29 Created: 2010-07-29 Last updated: 2022-01-28Bibliographically approved
Petersson, P., Kreter, A., Possnert, G. & Rubel, M. (2010). Nuclear micro-beam analysis of deuterium distribution in carbon fibre composites for controlled fusion devices. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 268(11-12), 1833-1837
Open this publication in new window or tab >>Nuclear micro-beam analysis of deuterium distribution in carbon fibre composites for controlled fusion devices
2010 (English)In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, E-ISSN 1872-9584, Vol. 268, no 11-12, p. 1833-1837Article in journal (Refereed) Published
Abstract [en]

Probes made of carbon fibre composite NB41 were exposed to deuterium plasmas in the TEXTOR tokamak and in a simulator of plasma-wall interactions, PISCES. The aim was to assess the deuterium retention and its lateral and depth distribution. The analysis was performed by means of D(He-3, p)4He and C-12(He-3, p)14N nuclear reactions analysis using a standard (1 mm spot) and micro-beam (20 mu m resolution). The measurements have revealed non uniform distribution of deuterium atoms in micro-regions: differences by a factor of 3 between the maximum and minimum deuterium concentrations. The differences were associated with the orientation and type of fibres for samples exposed in PICSES. For surface structure in the erosion zone of samples exposed to a tokamak plasma the micro-regions were more complex. Depth profiling has indicated migration of fuel into the bulk of materials.

Place, publisher, year, edition, pages
Amsterdam: Elsevier, 2010
Keywords
Nuclear reaction analysis, Micro-beam, Deuterium, Tokamak, Carbon composites
National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:uu:diva-128872 (URN)10.1016/j.nimb.2010.02.024 (DOI)000278702300031 ()
Available from: 2010-07-29 Created: 2010-07-29 Last updated: 2022-01-28Bibliographically approved
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