The PRISMA Magnetic Spectrometer

PRISMA is a large-acceptance magnetic spectrometer for heavy ions operating at the Laboratori Nazionali di Legnaro. Its design is based on a very simple quadrupole-dipole configuration, with no hardware elements correcting for the optical aberrations, which are corrected instead via a software reconstruction of the trajectories of the nuclei inside the spectrometer. The trajectories are deduced from the point of entrance in the spectrometer and in the focal plane, where position-sensitive detectors are placed. The start detector of PRISMA is based on an MCP, while the focal plane detector is based on a MWPPAC. These detectors provide also a time-of-flight measurement. An ionisation chamber placed after the MWPPAC measures the charge and total energy of the incoming ions.