TY  - JOUR
AU  - Spilker, B.
AU  - Linke, J.
AU  - Loewenhoff, Th.
AU  - Pintsuk, G.
AU  - Wirtz, M.
TI  - High Pulse Number transient heat loads on beryllium
JO  - Nuclear materials and energy
VL  - 12
SN  - 2352-1791
CY  - Amsterdam [u.a.]
PB  - Elsevier
M1  - FZJ-2017-07171
SP  - 1184 - 1188
PY  - 2017
AB  - 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 0.14–1.0 GW m−2, as they can be expected for mitigated Type 1 ELMs in ITER, pulse durations in the range of 0.08–1.0 ms, 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 = 22–25 MW m−2s0.5 for 102 pulses to FHF < 12 MW m−2s0.5 for 103 pulses. However, a saturation of the thermally induced damage was observed for FHF ≤ 9 MW m−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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000417293300195
DO  - DOI:10.1016/j.nme.2016.11.032
UR  - https://juser.fz-juelich.de/record/838594
ER  -