Meeting on results from WEST C3 marker PFUs
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Europe/Berlin
Description
https://us02web.zoom.us/j/84937716002?pwd=MUVkWThiOVovRW14Tm5BRjFqcFk2dz09
Meeting ID: 849 3771 6002
Passcode: 712197
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09:00
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09:05
Introduction 5mSpeaker: Antti Hakola (TEKES / VTT)
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09:05
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09:15
Overview of C3 marker PFUs and sample distribution 10mSpeakers: Dr Elodie Bernard, Dr Mathilde Diez (CEA)
- Background information on the two C3 marker tiles that were handed over for surface analyses
- Introduction of the s-coordinate system, distribution of core samples, and discussion on goals of this meeting
- WEMA database for sample locations, instructions to the sent to all soon, first step is "technical passport" of the samples
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09:15
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09:25
Broad-beam RBS/NRA results: overview of erosion/deposition patterns (MPG) 10mSpeakers: Martin Balden (IPP), Matej Mayer (IPP)
- NRA and RBS analyses: standard broad beam, measurements along central line, interval 12.5 mm
- C3-34i: D, B, C, and O (indirectly) deposition profiles and W thickness changes determined (except for region with very thick deposits)
- C3-22o: generally thinner deposits and strongly erosion-dominated region
- NB! thick deposits after C4 have become even thicker --> potential issues in getting through them; in addition, peaks in terms of the s coordinates are shifted
- D largely trapped in co-deposits but also in eroded regions in small depressions (shadowed from plasma) --> calls for micro NRA
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09:25
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09:35
Broad-beam PIXE/NRA/RBS results - correspondence to MPG results (JSI) 10mSpeakers: Mitja Kelemen (JSI), Sabina Markelj (JSI)
- Broad beam analyses (PIXE, NRA) of selected core samples + comparison with MPG results; measurements also in the poloidal direction (=along the central line)
- PIXE allows further insights into the concentrations of trace elements (like metallic impurities)
- Relatively good agreement for NRA between IPP and JSI - except for C3-34iH (boundary region between thin and thick deposits) --> is this due to averaging over 5 successive measurement points? or delamination of the deposits partly or totally? Elzbieta and Martin says that removal locally is possible
- Also W thicknesses differ (but this may be due to DAQ at JSI) --> action on Mitja to re-check
- In addition, discrepancy of a factor of 1.5-2 between NRA data is large, should be only ~20% --> we should pay more attention to the cross-lab comparison! --> action on AH, MD, and EB to organize follow-up meetings!
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09:35
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09:45
Broad-beam PIXE/NRA/RBS results - correspondence to MPG results (IST) 10mSpeakers: Eduardo Alves, Rodrigo Mateus (IST)
- Applied the JET analysis chamber, boron quantification challenging; 4 points per sample at every 3-4 mm (and deviating from SIMS spots toroidally by ~2 mm)
- Strong deposits on C3-34iK --> consistent with MPG data --> action on Rodrigo to make a graphical comparison between MPG and IST and to determine how well they agree
- For next set of marker samples, the Mo interlayer should be thicker (~3-4 times) --> would simplify analyses and interpretation
- Cu available on some places, consistent with also microscopy analyses; stainless steel splashes visible as well --> due to arcing from SS panels (but very local phenomenon)
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09:45
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09:50
NRA results and correspondence to MPG results (NCSRD) 5mSpeaker: Konstantina Mergia (National Centre for Scientific Research “Demokritos”)
- two samples analyzed; IBA with D beam and interpretation using SIMNRA --> mainly Mo and W profiles could be extracted, agreement within ~50%
- SEM: indicates Fe and Cr, consistently with other observations; XRF: indicate their concentrations typically <0.3 at.% and generally <1 at.%
- Samples may have some additional dust on the surfaces (no special cleaning performed) but anything else is related to the features of the deposits --> one has to pay attention to inhomogeneous distribution of particles and averaging of the obtained data
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09:50
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09:55
RBS and TOF-ERDA measurements: elemental footprint and layer thickness (RBI) 5mSpeaker: Ivancica Bogdanovic Radovic (RBI)
- TOF-ERDA analyses of two samples, measurements along the central line, distance between spots ~3 mm; in addition, analyses in toroidal direction --> why this time little H visible on the samples (the latter set of measurements made 8 months after the first round)? Samples stored in desiccators but not in vacuum
- Main problem: samples possibly too rough for fully reliable analyses
- He on these samples just around the detection limit --> good reference case for comparing C4 results
- Maybe escaping of H due to complex (and slow) boron chemistry? Observed F originating from the production process?
- Action to repeat measurements closer to the original measurement point to see what really has happened in the meantime
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09:55
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10:00
TOF-ERDA and NRA measurements: elemental footprint and fuel content (VR) 5mSpeaker: Per Petersson (VR)
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10:00
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10:05
GDOES and XPS measurements: elemental footprint and layer thickness (IAP) 5mSpeaker: Dr Eduard Grigore
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10:05
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10:10
SIMS results for elemental depth profiles (VTT) 5mSpeaker: Antti Hakola (TEKES / VTT)
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10:10
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10:15
LIBS results for elemental depth profiles (UT) 5mSpeakers: Dr Jogi Indrek, Dr Peeter Paris
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10:15
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10:45
Discussion 30m
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10:45
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10:55
SEM/EDX results for overview of surface modifications (MPG) 10mSpeakers: Martin Balden (IPP), Matej Mayer (IPP)
- Overview of microscopy measurements given
- Thick deposits experienced delamination and peeling off; crack network visible as well
- In strongly eroded area only remnants of Mo left (erosion > 1 micron)
- Arcing also could lead to delamination, arcs burn through coating; weak arcing, in contrast, have led to no measurable depth of the arc traces and indicate deposition outside of the arc features
- Some analyses made for the side faces of tiles (=poloidal gaps)
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10:55
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11:05
SEM/EDX and FIB measurements: surface structure and microscale compositions (IPPLM) 10mSpeaker: Elzbieta Fortuna-Zalesna (IPPLM)
- Microscopy studies of selected inner and outer divertor tiles
- No big differences observed between outer-divertor samples; no issues with marker-layer adhesion seen
- Inner-divertor samples from different characteristic regions: Mo reaches the surface in stripes on the erosion-dominated zone, flaky surfaces in the region with thick stratified deposits, Cu etc. can be seen in the deposits and not only on the surface
- Matej: quantitative information? fraction of pores in a particular deposit? What could be gained from this?
- Interesting reference case with respect to analysis of C4 samples
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11:05
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11:10
SEM/EDX and XRF measurements: surface structure and microscale compositions (NCSRD) 5mSpeaker: Konstantina Mergia (National Centre for Scientific Research “Demokritos”)
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11:10
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11:15
XRF measurements: surface structure and microscale compositions (IAP) 5mSpeakers: Dr Eduard Grigore, Dr Ion Tiseanu
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11:15
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11:45
Discussion 30m
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11:45
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12:00
Final remarks and future actions 15mSpeaker: Antti Hakola (TEKES / VTT)
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09:00
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09:05