  Small (~50km scale), irregular features seen in Cassini images to be
emanating from Saturn's F ring have been termed mini-jets by Attree et al.
(2012). One particular mini-jet was tracked over half an orbital period,
revealing its evolution with time and suggesting a collision with a local
moonlet as its origin. In addition to these data we present here a much more
detailed analysis of the full catalogue of over 800 F ring mini-jets, examining
their distribution, morphology and lifetimes in order to place constraints on
the underlying moonlet population. We find mini-jets randomly located in
longitude around the ring, with little correlation to the moon Prometheus, and
randomly distributed in time, over the full Cassini tour to date. They have a
tendency to cluster together, forming complicated `multiple' structures, and
have typical lifetimes of ~1d. Repeated observations of some features show
significant evolution, including the creation of new mini-jets, implying
repeated collisions by the same object. This suggests a population of <~1km
radius objects with some internal strength and orbits spread over 100km in
semi-major axis relative to the F ring but with the majority within 20km. These
objects likely formed in the ring under, and were subsequently scattered onto
differing orbits by, the perturbing action of Prometheus. This reinforces the
idea of the F ring as a region with a complex balance between collisions,
disruption and accretion.
