AbstractAll the alternatives considered for the reduced technical objectives/reduced cost international thermonuclear experimental reactor (RTO/RC ITER) foresee, as one of the methods for additional heating and current drive, the use of neutral injection. Two atomic deuterium beams, with 1 MeV energy and each with at least 16.7 MW power, are the reference for the engineering design of the system. The design of NB system developed for the ITER final design report (FDR) [1] is being modified to comply with the reduced size of the machine and to incorporate, if possible, some design improvements and simplifications. The analyses of overall power distribution and the maximum power densities on each of the beamline components have been updated. To obtain 16.7 MW neutral beam power, 35 MW ion beam power at the exit of the accelerator is necessary. Therefore, about 18 MW are deposited on the beamline components. Moreover, during the commissioning of the injectors, and the high voltage conditioning of the beam source, the full beam power is dumped and measured on a calorimeter. The beamline requires actively cooled high heat flux (HHF) components to exhaust high power density (up to 15 MW/m2) in steady state conditions. The operative life of this components (30 000 beam-on/beam off cycles, without replacement) requires, primarily, the verification of thermal fatigue safety margins. This paper describes the most relevant aspects of the mechanical design of the HHF components, focusing on the thermal and mechanical verifications.
AbstractAll the alternatives considered for the reduced technical objectives/reduced cost international thermonuclear experimental reactor (RTO/RC ITER) foresee, as one of the methods for additional heating and current drive, the use of neutral injection. Two atomic deuterium beams, with 1 MeV energy and each with at least 16.7 MW power, are the reference for the engineering design of the system. The design of NB system developed for the ITER final design report (FDR) [1] is being modified to comply with the reduced size of the machine and to incorporate, if possible, some design improvements and simplifications. The analyses of overall power distribution and the maximum power densities on each of the beamline components have been updated. To obtain 16.7 MW neutral beam power, 35 MW ion beam power at the exit of the accelerator is necessary. Therefore, about 18 MW are deposited on the beamline components. Moreover, during the commissioning of the injectors, and the high voltage conditioning of the beam source, the full beam power is dumped and measured on a calorimeter. The beamline requires actively cooled high heat flux (HHF) components to exhaust high power density (up to 15 MW/m2) in steady state conditions. The operative life of this components (30 000 beam-on/beam off cycles, without replacement) requires, primarily, the verification of thermal fatigue safety margins. This paper describes the most relevant aspects of the mechanical design of the HHF components, focusing on the thermal and mechanical verifications. 抄録低減技術目標・低コスト国際熱核融合実験炉（RTO/RC ITER）で検討されたすべての代替案において、追加加熱および電流駆動の一手法として、中性粒子入射の利用が見込まれている。1 MeVのエネルギーを有し、各々が少なくとも16.7 MWの出力を有する2本の重水素原子ビームが、システムの工学設計の参照基準となっている。最終設計報告書（FDR）[1]のために開発されたNBシステムの設計は、装置の小型化に対応し、可能であれば設計の改良および簡素化を組み込むために修正されている。各ビームライン構成要素における全体的なパワー分布と最大パワー密度の解析は更新されている。16.7 MWの中性ビーム出力を得るためには、加速器出口で35 MWのイオンビーム出力が必要である。したがって、約18 MWがビームライン構成要素に堆積する。さらに、入射器の試運転中およびビーム源の高電圧コンディショニング中は、全ビーム出力がカロリメータにダンプされ測定される。ビームラインには、定常状態で高パワー密度（最大15 MW/m²）を排熱するために、強制冷却式の高熱流束（HHF）構成要素が必要である。この構成要素の動作寿命（交換なしで30,000回のビームオン／ビームオフサイクル）には、主として熱疲労安全余裕の検証が必要である。本論文では、HHF構成要素の機械設計の最も関連性の高い側面について、熱的および機械的検証に焦点を当てて述べる。