24pE16P
IMPGYROコードによるGAMMA10プラズマ中のAr不純物輸送シミュレーション
Transport Simulation of Ar Impurities in the GAMMA10 Plasmas
using IMPGYRO code
高原啓輔1, 矢本昌平1, 巽瞭子1, 石橋和大1, シャヒヌル・イスラム2, 市村和也2,
畑山明聖1, 中嶋洋輔2
Keisuke Takahara1, Shohei Yamoto1, Ryoko Tatsumi1, Kazuhiro Ishibashi1, Md. Shahinul Islam2,
Kazuya Ichimura2, Akiyoshi Hatayama1, and Yosuke Nakashima2
慶應大1, 筑波大2
12
Keio Univ. , Univ. of Tsukuba
1. Introduction
In future fusion reactors, radiation cooling byinjecting impurities such as Ar and Ne is proposedas an efficient method to reduce the heat load to thedivertor plates. We have been developed the high-Z
impurity transport code IMPGYRO[1]. The purposeof this study is to understand the transport processof Ar and its effect on the heat load reduction in theGAMMA10 plasmas by the IMPGYRO code andthe 2-D divertor plasma transport program
developed in Ref. [2],[3].
2. ModelThe IMPGYRO code is a Kinetic Monte Carlocode for transport analysis of high-Z impurity ionsin magnetized plasmas. The code follows the fullgyro-motion without drift approximation. Thefriction force and the thermal force due to Coulomb
collision has been modeled by the Monte-Carlo
Binary Collision Method[4],[5]. Calculation of theimpurity charge state by ionization andrecombination process is important to calculate theLorentz force and the collisional force. Multi-stepionization and reombination processes are also
included by Monte-Calro method.
The IMPGYRO code, however, mainly deals
with high-Z impurities like W and Ar atomic data
has not been implemented. In this study, we areimproving the IMPGYRO code by implementing
Ar atomic data[6] into the code. In order to validate
the implementation, we have done a series of test
calculations in the spatially infinite plasma with theuniform temperature and density profiles with. Figure 1
shows the time evolution of the normalized
impurity density for each charge state. The time
evolution agrees well with those by the simple 0-D
rate equations. Figure 2 shows the time evolution ofthe average charge state of Ar impurity ions. It isconfirmed to be also in good agreement with thoseby the 0-D rate equations. The implementation ofAr atomic data and ionization/recombination
processes into the IMPGYRO code has beensuccessfully done.

3. GAMMA 10 simulation
Base on the above code validation, now we start
applying the IMPGYRO code to the end cell regionof the GAMMA 10. The background plasma profile
has been given by the 2-D divertor plasma transport
program developed in Ref. [2],[3]. The initial
results will be given in the poster presentation.

Fig. 1 Test simulation of Ar ionization and recombination
process in a uniform background plasma without magnetic field.
Time evolution of normalized Ar ion density for typical chargestate.

Fig. 2 The time evolution of the average charge state of Ar
impurity ions.
References[1] S. Yamoto, et al., J. Nucl. Mater., 463 615-619 (2015).
[2] H. Takeda, Ph. D. thesis, Univ. of Tsukuba (2013).
[3] T. Furuta, Master thesis, Keio Univ. (2012).
[4] T. Takizuka, H. Abe, J. Comp. Phys. 25 205-219 (1977).
[5] Y. Homma, A. Hatayama, J. Comp. Phys. 250 206-223(2013).
[6] D.Psot, R. Jensen, At. Date Nucl. Data Tables 20 397-439(1977).