1201. Non-destructive ultrasonic inspections of small-scale mock-ups provided with advanced tungsten armours for DEMO divertor targetRiccardo De Luca, Emanuele Cacciotti, Marco Cerocchi, Aljaž Iveković, Petra Jenuš, Marius Wirtz, 2025, original scientific article Abstract: Within the framework of the EUROfusion Consortium, the Characterization of armour, heat sinks materials and joints sub-project of the Work Package Material (WP-MAT) has been dedicated to the development of different tungsten (W) monoblock mock-ups equipped with advanced materials for divertor target applications in the EU-DEMO fusion reactor. Assessing the status of the relevant joining interfaces of these mock-ups, not only after fabrication but throughout the whole component lifetime, plays a key role in the qualification process. At the ENEA Special Technologies Laboratory (TES), a number of facilities have been built to perform non-destructive inspections of plasma-facing components for fusion applications by ultrasonic testing (UT). The present work reports on the results of the UT inspections assessing the structural integrity of the relevant joining interfaces of three small-scale mock-ups provided with advanced W armour materials, specifically W-matrix with W2C inclusions consolidated by Spark Plasma Sintering (SPS), K-doped rolled W and K-doped laminated W. The UT examinations are carried out after fabrication and after the high heat flux tests (HHFT) at the neutral beam facility GLADIS. All results confirm the high-quality joining achieved by HIP and HRP. During the HHF tests of mock-ups, after a few hundred HHFT cycles defects are detected at the joining interfaces, due to debonding, delamination and W material cracks mainly affecting the loaded zone. The ultrasonic pulse-echo technique provides not only the size and position of the defects in the plane orthogonal to the ultrasonic beam, but also their depth in the material. During the analysis, the probe is inserted inside the pipe and the mock-up is examined in a cylindrical configuration. The coupling medium (demineralized water) is poured only inside the pipe. The main inspection parameters and the piezoelectric probes are chosen to obtain the maximum resolution in accordance with the thickness and joining interfaces to be analyzed.
Keywords: DEMO, divertor, advanced tungsten, high heat flux test, non-destructive test, ultrasonic examination
Published in DiRROS: 03.09.2025; Views: 283; Downloads: 128
 Full text (775,68 KB)
This document has many files! More... |
1202. Deuterium retention in tungsten, tungsten carbide and tungsten-ditungsten carbide compositesPetra Jenuš, Anže Abram, Saša Novak, Mitja Kelemen, Matic Pečovnik, Thomas Schwarz-Selinger, Sabina Markelj, 2023, original scientific article Abstract: The selection of the most suitable material for the EU DEMO divertor is still underway. Current research focuses on the development of tungsten-based materials for plasma-facing applications. In addition to other requirements, the candidate material must also exhibit low intrinsic hydrogen isotope retention. To verify the suitability of the tungsten carbide-containing materials, we examined the effect of carbon in the form of carbide or free carbon on deuterium (D) retention. The samples were consolidated by Field Assisted Sintering (FAST) and examined in terms of phase composition and microstructure before the d-retention studies. The Nuclear Reaction Analysis (NRA) technique was used to determine the depth distribution of D after the exposure to D plasma (fluence of 1.3 × 1024 D/m2 and 1.3 × 1025 D/m2 and an exposure temperature of 370 K and 523 K, respectively). Thermal Desorption Spectroscopy (TDS) was used to measure the D desorption spectra. The surfaces of samples exposed to D plasma were also examined in terms of microstructure by scanning electron microscopy. The study has shown that apart from the d-fluence and exposure temperature, the materials’ composition plays a vital role in d-retention, accompanied by blisters and pillar formation. The lowest d-retention was observed for tungsten and the highest in the W-W2C composite. The blisters and pillars were formed in these two materials but not in the WC, which also contains free carbon. At higher D fluence, approximately 15 to 20-times more blisters and pillars were formed in the W-W2C composite than in the tungsten prepared by the same method. The results suggest that the number of defects causing higher d-retention is the highest in W-W2C. On the other hand, the absence of surface irregularities in the WC-C sample after D retention studies indicates that the cause for higher D retention does not lie in the carbides, but, presumably, the microstructural and crystal lattice defects govern the D retention in tungsten-tungsten carbide systems.
Keywords: tungsten, (di)tungsten carbide, deuterium, nuclear reaction analysis, thermal desorption spectroscopy
Published in DiRROS: 03.09.2025; Views: 360; Downloads: 142
Full text (5,58 MB)
This document has many files! More... |
1203. |
1204. Spoprijemanje z rakom dojk : napotki za obvladovanje duševne stiskeAndreja Cirila Škufca Smrdel, Tina Rus, Mirjam Rojec, Tamara Stergar, 2024, not set Keywords: rak dojke, medosebne komunikacije, matere in otroci, nespečnost, utrujenost, kognitivne motnje, psihološki nasveti, pomoč, zdravstvene ustanove
Published in DiRROS: 03.09.2025; Views: 308; Downloads: 94
 Link to file |
1205. |
1206. Shooting activities as the potential influence on the environment at the Pokljuka biathlon center, SloveniaValentina Pezdir, Mateja Gosar, 2025, original scientific article Abstract: Biathlon activities can have negative effects on the environment due to the processes occurring during shooting, as the biathlon ammunition contains significant amounts of Pb, Cu and Sb. To determine these effects, we looked into the presence of lead-bearing particles in the vicinity of a shooting range in Rudno polje, Pokljuka, in Slovenia. Particles were collected from snow and later analysed using SEM/EDS, where we focused on the lead-bearing particles. These particles are composed of mainly lead or lead oxides/hydroxides with trace presence of Cu and Sb, both of which are commonly related to ammunition used in biathlon shooting and other shooting activities. To confirm that the particles originated from shooting, we compared them with particles taken from an indoor shooting range as dust and residue in ammunition casings. Lead-bearing particles show morphological changes that are caused by high temperatures and pressures during the shooting process.
Keywords: atmospheric particles, ammunition residue, SEM/EDS
Published in DiRROS: 03.09.2025; Views: 343; Downloads: 103
Full text (3,16 MB) |
1207. Podporne oblike zdravljenja limfomov : vodnik za bolnikeLučka Boltežar, Milica Miljković, Urška Rugelj, Lorna Zadravec-Zaletel, 2023, dictionary, encyclopaedia, lexicon, manual, atlas, map Keywords: sistemsko zdravljenje, radioterapija, neželeni učinki, rehabilitacija, psihološka pomoč
Published in DiRROS: 03.09.2025; Views: 379; Downloads: 113
Full text (830,62 KB) |
1208. |
1209. |
1210. Comparison of grassland nematode communities in the European and middle eastern Mediterranean under different forage plantsMartin Ewald, Randy Ingelmann, Maria-Teresa Sebastià, Simon Wehbe, Angela Ribas, Stefania Mattana, Juliette Bloor, Katja Klumpp, Branko Lukač, Tomaž Žnidaršič, 2025, original scientific article Keywords: bioindicator, climate, climate change, drought, free-living nematodes, monoculture, plant type, soil micro-fauna
Published in DiRROS: 03.09.2025; Views: 350; Downloads: 170
Full text (1,24 MB)
This document has many files! More... |
