Simulation of Crab Waist Collisions in DAΦNE with KLOE-2 Interaction Region

After the successful completion of the SIDDHARTA experiment run with crab waist collisions, the electron-positron collider ${\rm DA}\Phi {\rm NE}$ has started routine operations for the KLOE-2 detector. Similarly to the SIDDHARTA configuration, the new interaction region exploits the crab waist collision scheme, but features certain complications including the experimental detector solenoid, compensating anti-solenoids, and tilted quadrupole magnets, that lead to significant coupling of the horizontal and vertical betatron motion. It is not immediately obvious if the crab waist scheme would be as efficient in the strongly coupled case as it was in the uncoupled configuration. We have performed simulations of beam-beam interactions in the collider taking into account the real machine nonlinear lattice. In particular, we have evaluated the effect of crab waist sextupoles and beam-beam interactions on the collider dynamical aperture and energy acceptance. A new betatron tune working point has been proposed for the ${\rm DA}\Phi {\rm NE}$ electron ring, and its implementation resulted in more than 20% background reduction and injection efficiency improvement. Exploiting this working point has allowed reaching the best present luminosity of $2.0 \times {10^{32}}\ \hbox{cm}^{-2}\ \hbox{s}^{-1}$. The numerical simulations have shown that for the given bunch currents in collision, the powering of the crab waist sextupoles should decrease the beam core blow up by a factor of 2 indicating that even higher luminosity can be achieved in ${\rm DA}\Phi {\rm NE}$ thus encouraging further collider optimization.