  During a cosmological first-order phase transition in a dark sector, fermion
dark matter particles $\chi$ can form macroscopic Fermi balls that collapse to
primordial black holes (PBHs) under certain conditions. The evaporation of the
PBHs produces a boosted $\chi$ flux, which may be detectable if $\chi$ couples
to visible matter. We consider the interaction of $\chi$ with electrons, and
calculate signals of the dark matter flux in the XENON1T, XENONnT,
Super-Kamiokande and Hyper-Kamiokande experiments. A correlated gravitational
wave signal from the phase transition can be observed at THEIA and $\mu$Ares.
An amount of dark radiation measurable by CMB-S4 is an epiphenomenon of the
phase transition.
