OSQAR Annual Report 2012

Both spare LHC dipoles used for OSQAR experiments have been affected to the LHC and removed from the SM18 test benches. Two new dipoles have been selected, installed and cold tested. Alignment tests with the laser beam have demonstrated that the beam pipe geometry of both these new dipoles is suitable for the OSQAR photon regeneration experiment, which is planned to restart in 2013. For the Vacuum Magnetic Birefringence (VMB) measurement, a significant progress has been achieved by measuring within one aperture of a LHC dipole the Cotton Mouton effect of N2 gas. The data analysis of the photon regeneration experimental run of 2011 have provided exclusion limits that confirm the present reference ones obtained by the ALPS collaboration.