## This content will become publicly available on August 16, 2020

# Numerical study of transition between even and odd toroidal Alfvén eigenmodes on EAST

## Abstract

Linear simulations of toroidal Alfvén eigenmodes (TAEs) driven by energetic particles (EPs) on EAST (Experimental Advanced Superconducting Tokamak) are performed using the hybrid-kinetic MHD model implemented in NIMROD code. Furthermore, the EAST equilibrium is reconstructed using the EFIT code based on the experimental measurement. The “slowing down” distribution is adopted for modeling the equilibrium distribution of the energetic ions from the deuterium neutral beam injection on EAST. The frequency, the dominant poloidal mode number, the radial location and the detailed 2D mode structure of the TAE/RSAE (Reverse Shear Alfvén Eigenmode)/EPM (energetic particle mode) modes are consistent between the eigenvalue analysis and the NIMROD simulation. As the β fraction of EP increases, a transition between even and odd TAEs occurs, along with that between the ballooning and antiballooning mode structures. It is demonstrated that when the β fraction of EP is close to the transition threshold, both types of TAEs coexist.

- Authors:

- Publication Date:

- Research Org.:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Univ. of California, Oakland, CA (United States); Univ. of Wisconsin, Madison, WI (United States)

- Sponsoring Org.:
- USDOE Office of Science (SC); National Natural Science Foundation of China (NNSFC)

- Contributing Org.:
- NIMROD Team

- OSTI Identifier:
- 1577600

- Alternate Identifier(s):
- OSTI ID: 1568916

- Grant/Contract Number:
- AC02-05CH11231; FG02-86ER53218; SC0018001

- Resource Type:
- Accepted Manuscript

- Journal Name:
- Physics of Plasmas

- Additional Journal Information:
- Journal Volume: 26; Journal Issue: 8; Journal ID: ISSN 1070-664X

- Publisher:
- American Institute of Physics (AIP)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY

### Citation Formats

```
None, None. Numerical study of transition between even and odd toroidal Alfvén eigenmodes on EAST. United States: N. p., 2019.
Web. doi:10.1063/1.5108693.
```

```
None, None. Numerical study of transition between even and odd toroidal Alfvén eigenmodes on EAST. United States. doi:10.1063/1.5108693.
```

```
None, None. Fri .
"Numerical study of transition between even and odd toroidal Alfvén eigenmodes on EAST". United States. doi:10.1063/1.5108693.
```

```
@article{osti_1577600,
```

title = {Numerical study of transition between even and odd toroidal Alfvén eigenmodes on EAST},

author = {None, None},

abstractNote = {Linear simulations of toroidal Alfvén eigenmodes (TAEs) driven by energetic particles (EPs) on EAST (Experimental Advanced Superconducting Tokamak) are performed using the hybrid-kinetic MHD model implemented in NIMROD code. Furthermore, the EAST equilibrium is reconstructed using the EFIT code based on the experimental measurement. The “slowing down” distribution is adopted for modeling the equilibrium distribution of the energetic ions from the deuterium neutral beam injection on EAST. The frequency, the dominant poloidal mode number, the radial location and the detailed 2D mode structure of the TAE/RSAE (Reverse Shear Alfvén Eigenmode)/EPM (energetic particle mode) modes are consistent between the eigenvalue analysis and the NIMROD simulation. As the β fraction of EP increases, a transition between even and odd TAEs occurs, along with that between the ballooning and antiballooning mode structures. It is demonstrated that when the β fraction of EP is close to the transition threshold, both types of TAEs coexist.},

doi = {10.1063/1.5108693},

journal = {Physics of Plasmas},

number = 8,

volume = 26,

place = {United States},

year = {2019},

month = {8}

}

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