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内容記述 |
We developed a bounce-time-based (BT) orbit-following Monte-Carlo code in order to calculate a fast ion transport in the previous work as an extension of the OFMC code in QST. In the BT method, we take a bounce time as a time step of the orbit following for the purpose of reducing computational resources. However, the BT method code has limitations in its realistic application. In order to reduce the limitation, we have developed a hybrid code with the BT method and a drift orbit-following method. In the code, we can switch the methods depending on conditions for each purpose. With using this hybrid code, we have reduced the difference between the BT method and drift orbit-following method in the distribution of fast ions and heating in the plasma central region, which was observed in the previous work, and have been able to adopt a realistic first wall as a loss boundary instead of a separatrix. We have also applied this hybrid approach to handle a fast ion transport in a toroidal field ripple. The hybrid calculation well reproduced the profiles of several quantities obtained by the drift orbit calculation alone while reducing the calculation time. |
