TY - JOUR
T1 - Plasma exhaust and divertor studies in Japan and Europe broader approach, DEMO design activity
AU - Asakura, Nobuyuki
AU - Hoshino, Kazuo
AU - Utoh, Hiroyasu
AU - Someya, Youji
AU - Suzuki, Satoshi
AU - Bachmann, Christian
AU - Reimerdes, Holger
AU - Wenninger, Ronald
AU - Kudo, Hironobu
AU - Tokunaga, Shinsuke
AU - Homma, Yuki
AU - Sakamoto, Yoshiteru
AU - Hiwatari, Ryoji
AU - Tobita, Kenji
AU - You, Jeong Ha
AU - Federici, Gianfranco
AU - Ezato, Koichiro
AU - Seki, Yohji
AU - Ueda, Yoshio
AU - Ohno, Noriyasu
N1 - Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2018/11
Y1 - 2018/11
N2 - Power exhaust scenario and divertor design for a steady-state Japan (JA) DEMO and a pulse Europe (EU) DEMO1 have been investigated as one of the most important common issues in Broader Approach DEMO Design Activity. Radiative cooling is a common approach for the power exhaust scenario. For the JA DEMO, development of the divertor design appropriate for high Psep/Rp ∼30 MW m−1 is required, while the radiation fraction in the main plasma (frad main = Prad main/Pheat) is ITER-level (0.40–0.45) and the exhaust power above the L- to H-mode power threshold (fLH = Psep/Pth LH) is large margin (∼2). For the EU DEMO1, larger frad main (=0.67) and smaller fLH (=1.2) plasma is required, using higher-Z impurity seeding, in order to apply ITER-level divertor (Psep/Rp = 17 MW m−1). ITER technology, i.e. water cooling with W-monoblock and Cu-alloy (CuCrZr) heat sink, is a baseline for JA and EU to handle the peak heat load of 10 MW m−2-level, and neutron flux and irradiation dose are comparable. For the JA DEMO, two different water-cooling pipes, i.e. CuCrZr and F82H steel, are proposed. For the EU DEMO1, the heat sink consists of all Cu-alloy pipe, and the divertor size is reduced with replacing the baffles by the breeding blankets. Choices of the heat sink components have been developed appropriate to the high irradiation dose condition. These JA and EU approaches of the power exhaust scenario will provide important case studies for the future decision of the DEMO divertor design.
AB - Power exhaust scenario and divertor design for a steady-state Japan (JA) DEMO and a pulse Europe (EU) DEMO1 have been investigated as one of the most important common issues in Broader Approach DEMO Design Activity. Radiative cooling is a common approach for the power exhaust scenario. For the JA DEMO, development of the divertor design appropriate for high Psep/Rp ∼30 MW m−1 is required, while the radiation fraction in the main plasma (frad main = Prad main/Pheat) is ITER-level (0.40–0.45) and the exhaust power above the L- to H-mode power threshold (fLH = Psep/Pth LH) is large margin (∼2). For the EU DEMO1, larger frad main (=0.67) and smaller fLH (=1.2) plasma is required, using higher-Z impurity seeding, in order to apply ITER-level divertor (Psep/Rp = 17 MW m−1). ITER technology, i.e. water cooling with W-monoblock and Cu-alloy (CuCrZr) heat sink, is a baseline for JA and EU to handle the peak heat load of 10 MW m−2-level, and neutron flux and irradiation dose are comparable. For the JA DEMO, two different water-cooling pipes, i.e. CuCrZr and F82H steel, are proposed. For the EU DEMO1, the heat sink consists of all Cu-alloy pipe, and the divertor size is reduced with replacing the baffles by the breeding blankets. Choices of the heat sink components have been developed appropriate to the high irradiation dose condition. These JA and EU approaches of the power exhaust scenario will provide important case studies for the future decision of the DEMO divertor design.
KW - Broader Approach DEMO Design Activity (BA DDA)
KW - DEMO
KW - Divertor design
KW - Impurity seeding
KW - Power exhaust
KW - Water-coolong divertor
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U2 - 10.1016/j.fusengdes.2018.04.104
DO - 10.1016/j.fusengdes.2018.04.104
M3 - Article
AN - SCOPUS:85046751871
SN - 0920-3796
VL - 136
SP - 1214
EP - 1220
JO - Fusion Engineering and Design
JF - Fusion Engineering and Design
ER -