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22-27 October 2018
Mahatma Mandir Conference Centre
Asia/Kolkata timezone

Energetic-ion Confinement Studies by using Comprehensive Neutron Diagnostics in the Large Helical Device

24 Oct 2018, 08:30
Mahatma Mandir Conference Centre

Mahatma Mandir Conference Centre

Gandhinagar (nearest Airport: Ahmedabad), India
Poster P3 Posters


Dr Kunihiro Ogawa (National Institute for Fusion Science)


Study on neoclassical and anomalous transport of energetic particle (EP) in the Large Helical Device (LHD) has been performed by means of escaping EP diagnostics. By starting deuterium operation of the LHD, confinement study of EPs has remarkably progressed by using newly developed comprehensive neutron diagnostics providing the information of EPs confined in the core region. Time evolution of total neutron emission rate ($S_n$) following the short pulse neutral beam (NB) injection is reproduced by drift kinetic simulation, indicating that beam ion transport can be described with neoclassical models. The vertical neutron camera (VNC) works successfully, demonstrating that neutron emission profile shifts according to magnetic axis position ($R_{ax}$). Correlated with helically-trapped EP driven resistive interchange mode (EIC) burst, substantial drop of ($S_n$) and change of neutron emission profile are observed, indicating the significant loss of helically-trapped beam ion due to the EIC mode. Time-resolved triton burnup study is performed for the first time in stellarator/heliotron so as to understand the alpha particle confinement. It is found that the triton burnup ratio which largely increases at inward shifted configurations is similar to that measured in tokamak having a similar minor radius with the LHD. We demonstrate the confinement capability of EPs toward a helical reactor and expansion of the energetic-ion physics study in toroidal fusion plasmas.
Country or International Organization Japan
Paper Number EX/P3-20

Primary author

Dr Kunihiro Ogawa (National Institute for Fusion Science)


Dr Hideo Nuga (National Institute for Fusion Science) Mr Hiroki Kawase (SOKENDAI) Dr Hiroyuki Yamaguchi (National Institute for Fusion Science) Prof. Masaki Osakabe (National Institute for Fusion Science) Prof. Mitsutaka Isobe (National Institute for Fusion Science) Mr Neng Pu (SOKENDAI) Dr Ryosuke Seki (National Institute for Fusion Science) Prof. Sadayoshi Murakami (Departement Nuclear Engineering, Kyoto University) Mr Shogo Maeta (Kyoto University) Dr Shuji Kamio (National Institute for Fusion Science) Prof. Takeo Nishitani (National Institute for Fusion Science) Mr Yasuyuki Saito (Kyoto University) Dr Yutaka Fujiwara (National Institute for Fusion Science)

Presentation Materials