Monte Carlo simulation for the Touschek effect with the crab-waist scheme

The Touschek effect is one of the dominant loss mechanisms for lepton storage rings of low emittance (i.e. high bunch density) and low or moderate beam energy. So, in the past years, for all lepton circular machines, either colliders or modern synchrotron light sources, either due to high bunch density or to beam energy, more and more efforts have been made for a comprehensive evaluation of this effect. This paper describes the simulation tool developed to evaluate the actions relevant to minimize the Touschek effect, such as position and shape of scrapers and detector shieldings, interaction region optics design with a particular attention to sextupoles for their relevant nonlinear effects. Relevant results obtained through the years at the low energy eþe collider DAфNE are presented. A reduction of the luminosity normalized to the background of more than 1 order of magnitude is obtained with an increase in luminosity from 10 to 10 cm 2 s 1 and a small decrease in lifetime. The corresponding data Monte Carlo simulation comparison for each action taken is presented, showing an overall good agreement.