SP B monitoring meeting 2024
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Europe/Berlin
Description
Join Zoom Meeting
https://us02web.zoom.us/j/89727094589?pwd=1YTvFz4uyoROHRIGtR1iFJCjzD6aDr.1
Meeting ID: 897 2709 4589
Passcode: 768000
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13:00
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13:15
Overview of SP B in 2024 - summary of activities and work against deliverables 15mSpeaker: Antti Hakola (TEKES / VTT)
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13:15
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13:25
SP B.1 - Exposure of W samples to PSI-2 plasmas 10mSpeaker: Oleksandr Marchuk (FZJ)
- New high-resolution spectroscopy system available in PSI-2 and measured W spectra analysed + modelled --> paper submitted
- First B layers exposed to PSI-2 and measured spectra analysed; also B-H lines observed + O and other elements --> to be revisited!
- Comparison exercise --> previously observed high erosion rates due to Ar2+ ions, sputtering by heavy impurities and problems in estimating ion flux on the target? --> now with new exposures (and altered parameters) more reasonable erosion estimates obtained --> ready to move to next phase! (and check the data with Ne)
- Next steps: repeat the exercise with Ne, then proceed to other W samples
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13:25
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13:35
SP B.1 - Influence of dust impacts on W coatings 10mSpeaker: Dr Marco De Angeli (ENEA-CNR Milan)
- Report on the different regimes upon response to dust impacts: deformation, disintegration or dust becoming bound on the surface --> depends on the coating properties and velocity of dust particles --> also native oxide layers on (W) surfaces can change the behaviour - but no boundary effect for coatings
- New samples produced in 2024: samples with half pristine, half coated surface + further studies performed
- Next steps: impact of oblique incidence and target + dust temperature on delamination shape; effect of coating thickness on delamination?
- Open question: response of B layers to dust impacts? But is this relevant in a reactor?!
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13:35
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13:45
SP B.2 - Overview of PWI activities in W7-X 10mSpeaker: Chandra Prakash Dhard (IPP)
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13:45
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13:55
SP B.2 - Erosion experiments on W7-X and related surface analyses 10mSpeaker: Matej Mayer (IPP)
- Boronization layers analysed from (i) W-coated wall tiles and (ii) MPM samples --> thickness and homogeneity determined, O gettering capacity 0.5-0.9 O/B
- 10-60 nm of B after a campaign, 5-15 nm after an individual boronization --> thin layers; how about exposure to air --> that may be an issue
- Next steps: sticking coefficient of B-H radicals? cavity samples --> challenging! comparable task on AUG!
- Also thick W7-X deposits being analyzed
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13:55
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14:05
SP B.2 - Overview of WEST tile analyses 10mSpeaker: Dr Mathilde Diez (CEA)
- Summary of the WEST PWIE activities --> see the slides for details & minutes from the Cadarache meeting in July
- New in 2024: study the effect of ripple on the erosion pattern --> to be continued also in 2025 (MPG, CEA, IAP, others?)
- New in 2024-2025: studying deposits from high-fluence campaigns --> include into analysis programme in 2025
- New in 2025: analysis of monoblock samples; Phase 1 samples cut and ready to be shipped outside of CEA
- Next steps: publications (IAEA, PFMC - He results) + which labs can analyse full tiles + monoblocks
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14:05
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14:15
SP B.3 - TOF-ERDA analyses of WEST samples 10mSpeaker: Ivancica Bogdanovic Radovic (RBI)
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14:15
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14:25
SP B.3 - Surface analyses of WEST monoblock samples 10mSpeaker: Konstantina Mergia (National Centre for Scientific Research “Demokritos”)
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14:25
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14:35
SP B.4 - production of W reference samples 10mSpeaker: Prof. David Dellasega (ENEA)
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14:35
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14:45
SP B.4 - production, characterization, and exposure of B reference samples 10mSpeaker: Anne Houben (FZJ)
- B layers produced and characterized (magnetron sputtering) --> B layers appear to detach from their W substrate (due to W oxide?) --> best to anneal W substrates before deposition and keep in vacuum (similar effect on steel but only after several months --> humidity effect)
- B erosion in PSI-2 --> erosion rates 0.26-0.43 nm/s (PSI-2 beam profile), quite consistent for long-term and short-term exposures (rate can increase up to 0.6 nm/s) - these obtained by spectroscopy!
- Next steps: comparison to layers produced by other groups
- Possible follow-up exercise: chemical erosion of B layers? Sabina can study this
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14:45
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14:55
SP B.4 - production and characterization of B reference samples 10mSpeaker: Eduardo Pitthan Filho (VR)
- B films produced by magnetron sputtering on W substrates --> layers appear to be stable but they can change color upon exposure to air (in minutes)
- Collection of data from W-B mixed layers and pure B coatings; proposal to carry out in situ experiments on H/D desorption
- NB! aging effect considerable (formation of boric acid)
- Detailed analysis of the layers carried out, combining multiple IBA techniques recommended --> new methods available for B detection
- Next steps: participate in the comparison exercise proposed by Anne
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14:55
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15:10
SP B.5 - Production of B and W dust particles 15mSpeakers: Dr Corneliu Porosnicu (IAP), Tomy Acsente (IAP)
- W dust particles: clear impact of deposition rate, D retention etc. by addition of water vapor on the production of nanoparticles; particles also become more "disconnected"
- B dust particles: produced using both magnetron sputtering (nanoparticles) and plasma arcing (big clusters) --> inclusion of H, N, and O changes the properties of dust particles + some notable differences compared to W dust
- Next step: comparing lab dust to dust coming from fusion devices + finishing the database
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15:10
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15:30
Discussion 20m
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15:30
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15:35
Final remarks and actions 5mSpeaker: Antti Hakola (TEKES / VTT)
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13:00
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13:15