  The performance of high beam power accelerators is strongly dependent on
appropriate injection, acceleration and extraction system designs as well as on
the way interactions of the beam with machine components are handled. The
experience of the previous ICFA High -Brightness Beam workshops has proven that
it is quite beneficial to combine analyses and discussion of these issues in
one group. A broad range of topics was presented and discussed at the Working
Group C sessions at the HB2012 Workshop. Highlights from the talks, outstanding
issues along with plans and proposals for future work are briefly described in
this report.

Accelerator Physics