Spin polarization produced in projectile fragmentation reactions

Projectile fragmentation is a demonstrated technique for producing fast beams of rare isotopes independent of chemical properties. With selection of appropriate reaction parameters, projectile fragmentation can produce isotopes with some degree of spin polarization. A kinematical model based on the conservation of linear and angular momentum qualitatively describes the polarization data.; A Monte Carlo code has been developed, based on this kinematical model, to calculate the induced fragment spin polarization produced in projectile fragmentation reactions. Quantitative predictions were realized by including the process of nucleon evaporation, realistic angular distributions, de-orientation caused by γ-ray emission and by correcting for the out of plane acceptance. Polarization calculated with this code quantitatively reproduces known polarization data.; The polarization of 37K produced from 150 MeV/A 36Ar on a 9Be target at a beam angle of +2° was measured. This was the first observation of polarization produced in a nucleon pickup reaction at fragmentation energies. The presence of polarization can be understood by extending the kinematical model used to understand polarization produced in fragmentation reactions. The qualitative agreement between the predicted and the experimental polarization validates the use of the kinematical conservation model to understand both polarization phenomena.