Tracking studies and performance simulations of the NSCL A1900 fragment separator

At the National Superconducting Cyclotron Laboratory (NSCL), secondary beams of often short-lived radioactive nuclei are produced by the technique of projectile fragmentation where a primary beam impinges on a thin target to produce a broad spectrum of isotopes with near-beam velocity. As a major element of a recently funded upgrade of the NSCL facility, an increased capacity fragment separator used to select a particular isotope will be constructed. The key features of the new fragment separator include a high rigidity (6.3 T-m) and large acceptance with a solid angle of 8 msr, momentum acceptance of ±3%, and an energy resolution of 0.1%. Tracking studies and machine simulations have been done to verify the optical stability and performance of the lattice. The results of these studies, including simulations of magnet misalignment and magnetic field errors, are presented in this paper