Abstract Details
Abstracts
Author: Yasutaro Nishimura
Requested Type: Poster
Submitted: 2017-02-28 03:13:00
Co-authors: J.C.Lyu
Contact Info:
National Cheng Kung University
1 University Rd.
Tainan, 70101
Taiwan
Abstract Text:
Particle and heat transport across the magnetic separatrix of
a tokamak divertor is investigated by a guiding center orbit
following calculation. In the presence of magnetic
stochasticity, magnetic field lines inside the separatrix can
be connected to the open magnetic field line regions.
Because of the motion along the field lines, after crossing
the separatrix, the particles can hit the divertor plates
within finite toroidal evolutions. As a first step, we employ
an analytical model for the magnetic structure, which is
given by the potential of the Duffing equation, to
incorporate both the closed and open magnetic field line
regions.
Magnetic flux coordinates can be employed both for the open
and closed field line regions, but not on the separatrix
because of the singular nature of the X-point. The safety
factor tends to infinity. In the very vicinity of the
separatrix, we employ Cartesian coordinate. For the orbit
calculation, an effective Coordinate transformation is the
key. The relation between the flux coordinate system and
Cartesian coordinate system is obtained by integrating the
magnetic field line equation. A global profile evolution is
discussed by analyzing statistical behavior of the test
particles. This work is supported by Taiwan
NSC 100-2112-M-006-021-MY3, MOST 103-2112-M-006-007,
and MOST 104-2112-M-006-019.
Comments: