High pulse number transient heat loads on beryllium
The experimental fusion reactor ITER will apply beryllium as first wall armor material. In present fusion experiments, e.g. ASDEX Upgrade, it has been detected that up to 25% of the plasma energy loss is deposited in non divertor regions during edge localized mode (ELM) events. Therefore, the impact...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2017-08-01
|
| Series: | Nuclear Materials and Energy |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2352179116300515 |
| _version_ | 1811280325589860352 |
|---|---|
| author | B. Spilker J. Linke Th. Loewenhoff G. Pintsuk M. Wirtz |
| author_facet | B. Spilker J. Linke Th. Loewenhoff G. Pintsuk M. Wirtz |
| author_sort | B. Spilker |
| collection | DOAJ |
| description | The experimental fusion reactor ITER will apply beryllium as first wall armor material. In present fusion experiments, e.g. ASDEX Upgrade, it has been detected that up to 25% of the plasma energy loss is deposited in non divertor regions during edge localized mode (ELM) events. Therefore, the impact of transient heating events on beryllium needs to be investigated to reliably predict the performance of the beryllium armor tiles under ITER operational conditions. In the present experiments, the electron beam facility JUDITH 2 was used to exert transient heat pulses with power densities of 0.14–1.0GWm−2, as they can be expected for mitigated Type 1 ELMs in ITER, pulse durations in the range of 0.08–1.0ms, and a number of pulses in the range of 103–107 on S-65 beryllium specimens that were brazed on an actively cooled copper structure. Thereby, a strong drop of the melting threshold was discovered from a heat flux factor FHF = 22–25MWm−2s0.5 for 102 pulses to FHF < 12MWm−2s0.5 for 103 pulses. However, a saturation of the thermally induced damage was observed for FHF ≤ 9MWm−2s0.5 after 105 pulses. This result indicated a promising performance of beryllium under a high number of transient heat pulses in ITER. Nevertheless, the synergistic effects between thermal loads, particle loads, and neutron irradiation might affect the saturation threshold and need to be investigated in future studies. Keywords: ELMs, Plasma facing materials, Beryllium, First wall, ITER, High heat flux testing, High pulse number |
| first_indexed | 2024-04-13T01:11:35Z |
| format | Article |
| id | doaj.art-e77b0db9e22d4e478aeb0ac01b0f3fba |
| institution | Directory Open Access Journal |
| issn | 2352-1791 |
| language | English |
| last_indexed | 2024-04-13T01:11:35Z |
| publishDate | 2017-08-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Nuclear Materials and Energy |
| spelling | doaj.art-e77b0db9e22d4e478aeb0ac01b0f3fba2022-12-22T03:09:08ZengElsevierNuclear Materials and Energy2352-17912017-08-011211841188High pulse number transient heat loads on berylliumB. Spilker0J. Linke1Th. Loewenhoff2G. Pintsuk3M. Wirtz4Corresponding author.; Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung, 52425 Jülich, GermanyForschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung, 52425 Jülich, GermanyForschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung, 52425 Jülich, GermanyForschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung, 52425 Jülich, GermanyForschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung, 52425 Jülich, GermanyThe experimental fusion reactor ITER will apply beryllium as first wall armor material. In present fusion experiments, e.g. ASDEX Upgrade, it has been detected that up to 25% of the plasma energy loss is deposited in non divertor regions during edge localized mode (ELM) events. Therefore, the impact of transient heating events on beryllium needs to be investigated to reliably predict the performance of the beryllium armor tiles under ITER operational conditions. In the present experiments, the electron beam facility JUDITH 2 was used to exert transient heat pulses with power densities of 0.14–1.0GWm−2, as they can be expected for mitigated Type 1 ELMs in ITER, pulse durations in the range of 0.08–1.0ms, and a number of pulses in the range of 103–107 on S-65 beryllium specimens that were brazed on an actively cooled copper structure. Thereby, a strong drop of the melting threshold was discovered from a heat flux factor FHF = 22–25MWm−2s0.5 for 102 pulses to FHF < 12MWm−2s0.5 for 103 pulses. However, a saturation of the thermally induced damage was observed for FHF ≤ 9MWm−2s0.5 after 105 pulses. This result indicated a promising performance of beryllium under a high number of transient heat pulses in ITER. Nevertheless, the synergistic effects between thermal loads, particle loads, and neutron irradiation might affect the saturation threshold and need to be investigated in future studies. Keywords: ELMs, Plasma facing materials, Beryllium, First wall, ITER, High heat flux testing, High pulse numberhttp://www.sciencedirect.com/science/article/pii/S2352179116300515 |
| spellingShingle | B. Spilker J. Linke Th. Loewenhoff G. Pintsuk M. Wirtz High pulse number transient heat loads on beryllium Nuclear Materials and Energy |
| title | High pulse number transient heat loads on beryllium |
| title_full | High pulse number transient heat loads on beryllium |
| title_fullStr | High pulse number transient heat loads on beryllium |
| title_full_unstemmed | High pulse number transient heat loads on beryllium |
| title_short | High pulse number transient heat loads on beryllium |
| title_sort | high pulse number transient heat loads on beryllium |
| url | http://www.sciencedirect.com/science/article/pii/S2352179116300515 |
| work_keys_str_mv | AT bspilker highpulsenumbertransientheatloadsonberyllium AT jlinke highpulsenumbertransientheatloadsonberyllium AT thloewenhoff highpulsenumbertransientheatloadsonberyllium AT gpintsuk highpulsenumbertransientheatloadsonberyllium AT mwirtz highpulsenumbertransientheatloadsonberyllium |