  Thermonuclear supernovae are the result of the violent unbinding of a white
dwarf, but the precise nature of the explosion mechanism(s) is a matter of
active debate. To this end, several specific scenarios have been proposed to
explain the observable traits of SNe Ia. A promising pathway is the
double-detonation scenario, where a white dwarf accretes a shell of helium-rich
material from a companion and a detonation in the resulting helium shell is the
primary cause of the explosion. Through a set of two-dimensional grid-based
simulations of this scenario we clearly distinguish three phases of evolution:
external helium-rich detonation, core compressive heating, and a final core
carbon burn. Though final disruption of the whole system is achieved at all
resolutions, only models with minimum resolutions of 4~km and better exhibit
all three phases. Particularly, core compression heating is only observed for
higher resolutions, producing qualitatively different nucleosynthetic outcomes.
We identify the effect of finer spatial resolution on the mixing of hot silicon
at the interface between the detonating helium layer and the underlying C/O WD
as a primary driver of these dynamic differences.
