  Accurate description of neutrino opacities is central both to the
core-collapse supernova (CCSN) phenomenon and to the validity of the explosion
mechanism itself. In this work, we study in a systematic fashion the role of a
variety of well-selected neutrino opacities in CCSN simulations where
multi-energy, three-flavor neutrino transport is solved by the isotropic
diffusion source approximation (IDSA) scheme. To verify our code, we first
present results from one-dimensional (1D) simulations following core-collapse,
bounce, and up to ~ 250 ms postbounce of a 15 $M_{\odot}$ star using a standard
set of neutrino opacities by Bruenn (1985). Detailed comparison with published
results supports the reliability of our three-flavor IDSA scheme using the
standard opacity set. We then investigate in 1D simulations how the individual
opacity update leads to the difference from the base-line run with the standard
opacity set. By making a detailed comparison with previous work, we check the
validity of our implementation of each update in a step-by-step manner.
Individual neutrino opacities with the largest impact on the overall evolution
in 1D simulations are selected for a systematic comparison in our
two-dimensional (2D) simulations. Special emphasis is devoted to the criterion
of explodability in the 2D models. We discuss the implications of these results
as well as the limitations and requirements for future towards more elaborate
CCSN modeling.
