Title: Kinetic particle simulations in a global toroidal geometry

Abstract

The gyrokinetic toroidal code has been upgraded for global simulations by coupling the core and scrape-off layer regions across the separatrix with field-aligned particle-grid interpolations. A fully kinetic particle pusher for high frequency waves (ion cyclotron frequency and beyond) and a guiding center pusher for low frequency waves have been implemented using cylindrical coordinates in a global toroidal geometry. The two integrators correctly capture the particle orbits and agree well with each other, conserving energy and canonical angular momentum. As a verification and application of this new capability, ion guiding center simulations have been carried out to study ion orbit losses at the edge of the DIII-D tokamak for single null magnetic separatrix discharges. The ion loss conditions are examined as a function of the pitch angle for cases without and with a radial electric field. We report the simulations show good agreement with past theoretical results and with the experimentally observed feature in which high energy ions flow out along the ion drift orbits and then hit the divertor plates. A measure of the ion direct orbit loss fraction shows that the loss fraction increases with the ion energy for DIII-D in the initial velocity space. Finally, as amore » further verification of the capability of the new code, self-consistent simulations of zonal flows in the core region of the DIII-D tokamak were carried out. All DIII-D simulations were performed in the absence of turbulence.« less

Authors:

De, S.  ^[1];

• Search DOE PAGES for author "De, S."
• Search DOE PAGES for ORCID "0000-0002-1020-968X"
• Search orcid.org for ORCID "0000-0002-1020-968X"

Singh, T. ^[1]; Kuley, A.  ^[1];

• Search DOE PAGES for author "Kuley, A."
• Search DOE PAGES for ORCID "0000-0003-2325-6597"
• Search orcid.org for ORCID "0000-0003-2325-6597"

Bao, J. ^[2]; Lin, Z.  ^[2];

• Search DOE PAGES for author "Lin, Z."
• Search DOE PAGES for ORCID "0000-0003-2007-8983"
• Search orcid.org for ORCID "0000-0003-2007-8983"

Sun, G. Y. ^[3]; Sharma, S. ^[4]; Sen, A. ^[5]

---

+ Show Author Affiliations

1. Indian Inst. of Science, Bangalore (India)
2. Univ. of California, Irvine, CA (United States)
3. Xiamen Univ. (China)
4. Inst. for Plasma Research, Bhat (India); Homi Bhabha National Inst., Mumbai (India)
5. Inst. for Plasma Research, Bhat (India)

Publication Date:

2019-08-20

Research Org.:

Univ. of California, Irvine, CA (United States)

Sponsoring Org.:

Board of Research in Nuclear Sciences; Science and Engineering Research Board; USDOE Office of Science (SC), Fusion Energy Sciences (FES); USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR). Scientific Discovery through Advanced Computing (SciDAC); China National Magnetic Confinement Fusion Energy Research Program; Indian Institute of Science (IISc); Indian National Science Academy (INSA)

OSTI Identifier:

1612905

Alternate Identifier(s):

OSTI ID: 1557910

Grant/Contract Number:  

SC0018270; 2013GB111000

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; Physics; Coordinate system; Plasma confinement; Cyclotron resonance; Plasma facing components; Theoretical and computational geophysics; Rigid body dynamics; Interpolation; Tokamaks; Plasma flows; Plasma dynamics