New simulations of physics background in Super Charm-tau factory detector with crossed vacuum pipes

New simulation of background particle fluxes generated by colliding beams is performed with FLUKA package for the Super C-Tau factory Detector (SCTD) with crossed vacuum pipes. Two processes are considered as main sources of luminosity generated background: two-photon production of electron-positron pairs and Bha Bha scattering with bremsstrahlung photon emission (radiative Bha Bha). The SCTD geometry is described corresponding to the last version of the Conceptual Design Report including detailed description of the interaction point region and final focus magnets. The magnetic field based on the calculation in ANSYS is introduced in the model. Main results of the simulation for beam energy of 3 GeV, luminosity of 10${}^{35}$ cm${}^{-2}$s${}^{-1}$ and 1.5 T magnetic field are the following: charged particle fluence in the region of the Inner Tracker (radius 5cm - 20 cm, Z between -30cm and 30 cm) is between 10${}^5$ particles/(cm${}^2$s) and $\sim$10${}^3$ particles/(cm${}^2$s); 1-MeV neutron equivalent fluence for Si in the regions corresponding to electronics of the Inner Tracker and the Drift Chamber is below 10${}^{11}$ n/(cm${}^2$y) and absorbed dose is below 100 Gy/y in the hottest regions of the detector.