Into the twilight zone: how does WIPL-D perform in quasistatics?

We focus on the question how well WLPL-D, a numerical code designed to tackle dynamical electromagnetic problems, can be applied to solving very low-frequency problems. In particular, the problem of the static polarizability of a dielectric sphere is calculated. This is done by enumerating the monostatic radar cross section of the object and taking the low-frequency limit. Peeling away the strong frequency dependence of the radar cross section, the remaining coefficient is proportional to the square of the static polarizability. The results show that there is around two decades of frequency range where the code works well and the situation is clearly in the quasistatic regime. In the example of a sphere of one-meter radius and relative permittivity 10, the low-frequency breakdown happens at around 10 kHz.