Guiding center¶

Equation in polar coordinates:

\[ \partial_t f(t,r,\theta) - \frac{\partial_{\theta}\Phi(r, \theta)}{r} \partial_r f(t,r,\theta) + \frac{\partial_{r}\Phi}{r} \partial_{\theta} f = 0. \]

Diocotron instability [CGH+14]