Experimental Verification of Entropy Cascade in 2-D GyroKinetic Turbulence by Velocity-Space structure measurement.
陳勁廷1*, 河森榮一郎1, 李宗懋1
1Institute of Space and Plasma Scienses., National Cheng Kung University, Tainan, Taiwan
* presenting author:勁廷陳, email:s0982680@mail.ncyu.edu.tw
This research aims at experimentally verifying an entropy cascade in two-dimensional (2-D) electrostatic turbulence of laboratory magnetized plasmas by means of velocity space measurement of ions.
A theory by Schekochihin et al [Phys. Rev. Lett. 103,015003 (2008)] predicts that the entropy cascade process is induced by a nonlinear phase-mixing, which connects electrostatic fluctuations in the real space and ion motions in the velocity-space.The theoretical prediction has been confirmed by 2-D gyrokinetic simulations [T. Tatsuno et al., Phys. Rev. Lett. 103, 015003 (2009)] and a wave-number spectrum measurement in the magnetized plasma experiment (MPX) at NCKU. In order to confirm the theoretical prediction more directly, we have been developing a novel diagnostic tool of velocity-space structures of gyrokinetic ions.In the presentation, we report its conceptual design and results of detailed
design using a particle orbit calculation code we have developed.

Keywords: Entropy Cascade, GyroKinetic Turbulence, Nonlinear phase-mixing