  In this article, we experimentally investigate the impact of a submillimetric
water jet on a horizontal surface heated well above the "static" Leidenfrost
temperature of water. We observe the transition from a regime where a single
drop grows at the impingement point to a regime of spray formation. The main
control parameter appears to be the jet Weber number ($\We$). The first regime
persists until $\We \lesssim 30$ whereas the spray formation occurs for $\We
\gtrsim 40$. Surprisingly, we found no influence of the hot plate's temperature
on the reported phenomena. We particularly focus on the second regime, where
the liquid jet spreads on the plate, forming a liquid sheet that eventually
lifts off and breaks into droplets. We characterized this regime by the radius
$r_c$ of the liquid sheet when it is still in contact with the plate and the
angle of ejection $\theta$ of the droplets. We further examine the ejected
droplets by characterizing their speed and sizes. Simple models are proposed to
predict the dependencies and order of magnitudes of $r_c$ and $\theta$. We also
aim to predict the critical Weber number at which the transition between the
two regimes occurs. Our models show reasonable agreement with our experimental
data. Finally, we compare the energy transferred from the jet to the droplets
with results reported in the literature for impacts on unheated surfaces,
finding a difference of nearly a factor 2.
