  Integrable optics is an innovation in particle accelerator design that
provides strong nonlinear focusing while avoiding parametric resonances. One
promising application of integrable optics is to overcome the traditional
limits on accelerator intensity imposed by betatron tune-spread and collective
instabilities. The efficacy of high-intensity integrable accelerators will be
undergo comprehensive testing over the next several years at the Fermilab
Integrable Optics Test Accelerator (IOTA) and the University of Maryland
Electron Ring (UMER). We propose an integrable Rapid-Cycling Synchrotron (iRCS)
as a replacement for the Fermilab Booster to achieve multi-MW beam power for
the Fermilab high-energy neutrino program. We provide a overview of the machine
parameters and discuss an approach to lattice optimization. Integrable optics
requires arcs with integer-pi phase advance followed by drifts with matched
beta functions. We provide an example integrable lattice with features of a
modern RCS - long dispersion-free drifts, low momentum compaction,
superperiodicity, chromaticity correction, separate-function magnets, and
bounded beta functions.
