Recent Developments in Integrable Optics for IOTA

The Integrable Optics Test Accelerator (IOTA) currently being commissioned at Fermilab was constructed for studying the concept of nonlinear integrable optics. The use of a special nonlinear magnetic element introduces large tune spread with amplitude while constraining the idealized dynamics by two integrals of motion. The requirement to preserve this integrability is that the intervening optics appear as a linear, symmetrically focusing lens. Effects such as chromaticity, higher-order dispersion, space charge and coupling may disrupt this assumption. At RadiaSoft, we have studied a variety of these effects in IOTA and how they relate to preserving the integrability of the machine. Here we discuss recent results on nonlinear decoherence, symplectic space-charge tracking, and the impact of synchro-betatron coupling on nonlinear optics.