  The development and construction of the Cherenkov Telescope Array (CTA) opens
up new opportunities for the study of very high energy (VHE, E>100 GeV)
sources. As a part of CTA, the ASTRI project, led by INAF, has one of the main
goals to develop one of the mini-arrays of CTA pre-production telescopes,
proposed to be installed at the CTA southern site. Thanks to the innovative
dual-mirror optical design of its small-sized telescopes, the ASTRI mini-array
will be characterized by a large field of view, an excellent angular
resolutioerrorn and a good sensitivity up to energies of several tens of TeV.
Pulsar wind nebulae, along with Supernova Remnants, are among the most abundant
sources that will be identified and investigated, with the ultimate goal to
move significantly closer to an understanding of the origin of cosmic rays
(CR). As part of the ongoing effort to investigate the scientific capabilities
for both CTA as a whole and the ASTRI mini-array, we performed simulations of
the Vela X region. We simulated its extended VHE gamma-ray emission using the
results of the detailed H.E.S.S. analysis of this source. We estimated the
resolving capabilities of the diffuse emission and the detection significance
of the pulsar with both CTA as a whole and the ASTRI mini-array. Moreover with
these instruments it will be possible to observe the high-energy end of SNRs
spectrum, searching for particles with energies near the cosmic-rays "knee"
(E~10^15 eV). We simulated a set of ASTRI mini-array observations for one young
and an evolved SNRs in order to test the capabilities of this instrument to
discover and study PeVatrons on the Galactic plane.
