“DELF”, a large solid angle detection system for heavy fragments

Abstract

To detect the heavy fragments ( Z > 8) emitted at large angle (30° < θ < 150°) in heavy ion collisions at GANIL, a large solid angle detection system has been built. It consists of 18 independent cells surrounding the target, the beam axis being the revolution axis. In each cell, a fragment penetrates at first into a parallel plate avalanche counter with localization which gives velocity, position and ∂E ∂x measurements and then into an ionization chamber with longitudinal field for the residual energy measurement. The Z evaluation is performed over a large range of velocities (0.05 < E A < 5 MeV/u) for atomic numbers ranging from 8 to 90.