Study of first orbit losses of 1 MeV tritons using the Lorentz orbit code in the LHD

作     者：Kunihiro OGAWA Mitsutaka ISOBE Takeo NISHITANI Sadayoshi MURAKAMI Ryosuke SEKI Hideo NUGA Neng PU Masaki OSAKABE LHD Experiment Group 

作者机构：National Institute for Fusion ScienceNational Institutes of Natural Sciences SOKENDAI (The Graduate University for Advanced Studies) Kyoto University Kyoto-city 

出 版 物：《Plasma Science and Technology》 (等离子体科学和技术（英文版）)

年 卷 期：2019年第21卷第2期

页      面：21-25页

核心收录：

学科分类：08[工学] 0827[工学-核科学与技术] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：supported partly by LHD project budgets (ULHH003 and ULHH034) 

主　　题：the Large Helical Device tritons energetic ion first orbit loss Lorentz orbit code 

摘      要：Shot-integrated measurement of the triton burnup ratio has been performed in the Large Helical Device. It was reported that the triton burnup ratio, defined as total DT neutron yield divided by total DD neutron yield, increases significantly in inward shifted configurations. To understand the magnetic configuration dependence of the triton burnup ratio, the first orbit loss fraction of 1 MeV tritons is evaluated by means of the Lorentz orbit code for various magnetic configurations. The first orbit loss of 1 MeV tritons is seen at t of less than 10-5 s and loss points of the triton are concentrated on the side of the helical coil case where the magnetic field is relatively weak. The significant decrease of the first orbit loss fraction by 15% is obtained with the inward shift of the magnetic axis position from 3.90 to 3.55 m. It is found that the decrease of first orbit loss is due to the reduction of the first orbit loss of transition and helically trapped tritons.