  We conduct one-dimensional stellar evolution simulations in the mass range
$13-20 M_{\odot}$ to late core collapse times and find that an inner vigorous
convective zone with large specific angular momentum fluctuations appears at
the edge of the iron core during the collapse. The compression of this zone
during the collapse increases the luminosity there and the convective
velocities, such that the specific angular momentum fluctuations are of the
order of j_{conv}~5x10^15cm^2/sec. If we consider that three-dimensional
simulations show convective velocities that are three to four times larger than
what the mixing length theory gives, and that the spiral standing accretion
shock instability in the post-shock region of the stalled shock at a radius of
~100km amplify perturbations, we conclude that the fluctuations that develop
during core collapse are likely to lead to stochastic (intermittent) accretion
disks around the newly born neutron star. In reaching this conclusion we also
make two basic assumptions with uncertainties that we discuss. Such
intermittent disks can launch jets that explode the star in the frame of the
jittering jets explosion mechanism.
