On the effects of different regimes of plasma pulses affecting the material due to their succession
The tungsten (>99.97% W) samples were irradiated on plasma focus device (PF-12), with deuterium (D) as a working gas, in Tallinn University in Estonia. Two of the samples serve as references, being irradiated in only one regime (either in harsh regime with heat flux factor ∼1000 MW s1/2 m2 for pl...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2019-01-01
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| Series: | Nuclear Materials and Energy |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2352179118302886 |
| _version_ | 1819296933438554112 |
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| author | Jana Paju Tõnu Laas Jaanis Priimets Berit Väli Veroonika Shirokova Katrin Laas |
| author_facet | Jana Paju Tõnu Laas Jaanis Priimets Berit Väli Veroonika Shirokova Katrin Laas |
| author_sort | Jana Paju |
| collection | DOAJ |
| description | The tungsten (>99.97% W) samples were irradiated on plasma focus device (PF-12), with deuterium (D) as a working gas, in Tallinn University in Estonia. Two of the samples serve as references, being irradiated in only one regime (either in harsh regime with heat flux factor ∼1000 MW s1/2 m2 for plasma and ∼1.5•105 MW s1/2 m2 for fast ions, or in the mild regime with heat flux factor ∼40–45 MW s1/2 m2 for plasma and ∼2000 MW s1/2 m2 for fast ions). Three of the samples received 27 pulses combining the two aforementioned regimes. The combined effects are obtained by using two different plasma flux values and also by varying the timing when the harsh regime is implemented during the irradiation cycle of each sample. The research is conducted by analyzing the SEM images of the damaged surfaces, measuring the electrical conductivity of the material in the bulk, studying the SEM images and micro-hardness of sample's cross-sections. This will enable to draw conclusions on the range of damages due to the varied succession of used regimes. The results are then combined to estimate the applicability of conductivity measurements instead of using destructive invasive measuring methods (i.e., measurement of micro-hardness and SEM imaging of cross sections).The aims of our research is to shed some light on (1) whether and how the succession of different series of irradiations with varying power flux densities affects the formation of damages on and within the samples and (2) estimating the three-dimensional damages that are created within the bulk of material due to high-temperature plasma and ion shockwaves. Our study indicates that the damage in bulk is related to the timing of harsh regime plasma pulses. The use of measurements of conductivity enables to estimate the future development of the damages in bulk of the material. Keywords: Electrical conductivity, Invasive methods, Micro-hardness, Tungsten, Plasma facing materials, PFC, Non-destructive testing, The order of succession of plasma pulses |
| first_indexed | 2024-12-24T05:05:59Z |
| format | Article |
| id | doaj.art-377b04feacc0484897887b2ec98f3d49 |
| institution | Directory Open Access Journal |
| issn | 2352-1791 |
| language | English |
| last_indexed | 2024-12-24T05:05:59Z |
| publishDate | 2019-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Nuclear Materials and Energy |
| spelling | doaj.art-377b04feacc0484897887b2ec98f3d492022-12-21T17:13:49ZengElsevierNuclear Materials and Energy2352-17912019-01-0118312320On the effects of different regimes of plasma pulses affecting the material due to their successionJana Paju0Tõnu Laas1Jaanis Priimets2Berit Väli3Veroonika Shirokova4Katrin Laas5School of Natural Sciences and Health, Tallinn University, Narva Road 25, Tallinn 10120, Estonia; Corresponding author.School of Natural Sciences and Health, Tallinn University, Narva Road 25, Tallinn 10120, EstoniaSchool of Natural Sciences and Health, Tallinn University, Narva Road 25, Tallinn 10120, EstoniaSchool of Natural Sciences and Health, Tallinn University, Narva Road 25, Tallinn 10120, EstoniaSchool of Natural Sciences and Health, Tallinn University, Narva Road 25, Tallinn 10120, Estonia; Center for Science and Engineering, Virumaa College of Tallinn University of Technology, Järveküla Road 75, Kohtla-Järve 30322, EstoniaSchool of Natural Sciences and Health, Tallinn University, Narva Road 25, Tallinn 10120, EstoniaThe tungsten (>99.97% W) samples were irradiated on plasma focus device (PF-12), with deuterium (D) as a working gas, in Tallinn University in Estonia. Two of the samples serve as references, being irradiated in only one regime (either in harsh regime with heat flux factor ∼1000 MW s1/2 m2 for plasma and ∼1.5•105 MW s1/2 m2 for fast ions, or in the mild regime with heat flux factor ∼40–45 MW s1/2 m2 for plasma and ∼2000 MW s1/2 m2 for fast ions). Three of the samples received 27 pulses combining the two aforementioned regimes. The combined effects are obtained by using two different plasma flux values and also by varying the timing when the harsh regime is implemented during the irradiation cycle of each sample. The research is conducted by analyzing the SEM images of the damaged surfaces, measuring the electrical conductivity of the material in the bulk, studying the SEM images and micro-hardness of sample's cross-sections. This will enable to draw conclusions on the range of damages due to the varied succession of used regimes. The results are then combined to estimate the applicability of conductivity measurements instead of using destructive invasive measuring methods (i.e., measurement of micro-hardness and SEM imaging of cross sections).The aims of our research is to shed some light on (1) whether and how the succession of different series of irradiations with varying power flux densities affects the formation of damages on and within the samples and (2) estimating the three-dimensional damages that are created within the bulk of material due to high-temperature plasma and ion shockwaves. Our study indicates that the damage in bulk is related to the timing of harsh regime plasma pulses. The use of measurements of conductivity enables to estimate the future development of the damages in bulk of the material. Keywords: Electrical conductivity, Invasive methods, Micro-hardness, Tungsten, Plasma facing materials, PFC, Non-destructive testing, The order of succession of plasma pulseshttp://www.sciencedirect.com/science/article/pii/S2352179118302886 |
| spellingShingle | Jana Paju Tõnu Laas Jaanis Priimets Berit Väli Veroonika Shirokova Katrin Laas On the effects of different regimes of plasma pulses affecting the material due to their succession Nuclear Materials and Energy |
| title | On the effects of different regimes of plasma pulses affecting the material due to their succession |
| title_full | On the effects of different regimes of plasma pulses affecting the material due to their succession |
| title_fullStr | On the effects of different regimes of plasma pulses affecting the material due to their succession |
| title_full_unstemmed | On the effects of different regimes of plasma pulses affecting the material due to their succession |
| title_short | On the effects of different regimes of plasma pulses affecting the material due to their succession |
| title_sort | on the effects of different regimes of plasma pulses affecting the material due to their succession |
| url | http://www.sciencedirect.com/science/article/pii/S2352179118302886 |
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