Projectile-like fragment production studies using coincident neutrons*

The production of nuclei near the neutron dripline at Radioactive Ion Beam (RIB) facilities requires multi-step reactions between primary beams and targets. Understanding these multi-step reactions narrows constraints on secondary beam production rates and therefore optimizes beam time. Experimental planning typically depends on empirical parameterizations like EPAX, but results can differ from experiment [1].  At the National Superconducting Cyclotron Laboratory (NSCL), the MoNA Collaboration measured coincident neutrons and charged fragments in the ³²Mg + ⁹Be reaction in order to study the formation of the precursor states, i.e. projectile-like fragments (PLF’s).  Charged fragments were deflected by the Sweeper magnet into a suite of charged particle and coincidence neutrons measured in the Modular Neutron Array (MoNA).  The rigidity of the Sweeper was varied during this experiment allowing the detection of a range of isotopes. Analysis of the neutron multiplicity and energy distributions in coincidence with sodium, neon, or fluorine charged fragments will be presented.

[1] M. Mocko, et al.,  Physical Review C 74 054612 (2006)