  Propylene oxide, a favorite target of experimental and theoretical studies of
circular dichroism, was recently discovered in interstellar space, further
amplifying the attention to its role in the current debate on protobiological
homochirality. In the present work, a photoelectron-photoion-photoion
coincidence technique, using an ion-imaging detector and tunable synchrotron
radiation in the 18.0-37.0 eV energy range, permits: (i)-to observe six
double-ionization fragmentation channels, their relative yields being accounted
for about two-thirds by the couple (C2H4+, CH2O+), one-fifth by (C2H3+, CH3O+);
(ii)-to measure thresholds for their openings as a function of photon energy;
(iii)-to unravel a pronounced bimodality for a kinetic-energy-released
distribution, fingerprint of competitive non-adiabatic mechanisms.
