The UA4/2 experiment at the CERN SpS collider

Abstract The UA4/2 experiment performed at CERN to measure the ratio of the real to the imaginary part of the forward elastic scattering amplitude is described. The accent is placed on the improvements with respect to the previous UA4 experiment, especially on the much improved design of the high-β insertion and a high-resolution, highly multiplexed scintillating fiber tracking detector.