SuperKEKB commissioning seminar
Fast luminosity measurements are very important for feedback and optimization in the presence of dynamic instabilities of the beam. In our studies, we aim for a precision of 10x-3 in 1 to 10 ms. We use diamond sensors, thanks to their radiation hardness and fast signal, to be placed outside the beam pipe in both rings downstream from the interaction point to detect Radiative Bhabha at zero photon scattering angle
thanks to their large cross section.
I will present simulation results by SAD and GEANT4 of the signals and precisions as well as the design of the vacuum chamber in the LER at which we place our sensors for phase 2.
For phase1, We are studying backgrounds from single beams ( Bremsstrahlung, Touschek, Coulomb). In this respect, I will present few preliminary results of our first acquisitions in addition to some simulation results by SAD ( Ohnishi san's code ).