Speaker
Ricardo Solano Piedra
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P5.1052.pdf
Full-wave simulation of mode-converted electron Bernstein waves at very
low magnetic field in the SCR-1 Stellarator
R. Solano-Piedra1 , A. Köhn2 , V.I. Vargas1 , E. Meneses3 , D. Jiménez 3 , A. Garro-Vargas3 ,
F. Coto-Vílchez1 M.A. Rojas-Quesada1 , D. López-Rodríguez1 , J. Sánchez-Castro1 ,
J. Asenjo1 and J. Mora1
1 Plasma Laboratory for Fusion Energy and Applications, Instituto Tecnológico de Costa
Rica, Cartago, P.O.Box 159-7050, Costa Rica.
2 IGVP, University of Stuttgart, Germany.
3 Advanced Computing Laboratory, Costa Rica National High Technology Center, CENAT,
San José, Costa Rica
SCR-1 is a 2-field period small modular Stellarator (R = 247.7 mm, R/a = 6.2, ιa = 0.264)
with a very low magnetic field (< B >= 41.99 mT) and an ECR heating frequency of 2.45 GHz
(5 kW). Few studies on conversion of electrostatic Bernstein waves under these conditions have
been performed in Stellarators [1, 2]. This work presents the results of converting electrostatic
Bernstein waves in the SCR-1 Stellarator using the full wave code IPF-FDMC [3], taking the
3D magnetic field obtained by VMEC code as input and the experimental electron density pro-
file obtained using a Langmuir probe. New microwave heating scenarios that take the SCR-1’s
vacuum vessel into account in order to improve the O-X conversion due to reflection of the in-
coming radiation from the ECRH system are presented. The results indicate a single pass O-X
mode conversion is around 3%. The possible location of a microwave antenna and its character-
istics for proper function in SCR-1 stellarator are explained. Additionally, the improvements in
BS-SOLCTRA code (Biot-Savart Solver for Compute and Trace Magnetic Fields) are shown.
This code was developed by our research group to calculate 3D magnetic fields and display the
magnetic surfaces in SCR-1. The road to convert it into a parallel and high-performance com-
puting platform for tracing particles in SCR-1 is shown. Finally, the results of the comparison
of the flux surfaces measured with an electron beam and fluorescent rod, with computed flux
surfaces by means of BS-SOLCTRA code are shown. Similarly, the designs of the magnetic
diagnostics (Rogowski, Voltage Loops and Mirnov) and the bolometer that will be installed in
SCR-1 are presented.
References
[1] Y. Podoba et al, Physical Review Letters. 98, 25 (2007).
[2] R. Ikeda et al, Physics of Plasmas, 15 , 7, (2008).
[3] A. Köhn et al, Plasma Physics and Controlled Fusion 55, 1 (2013).
