  A High Rigidity Spectrometer (HRS) has been designed for experiments at the
Facility for Rare-Isotope Beams (FRIB) at Michigan State University (MSU). The
HRS will allow experiments to be performed with the most exotic neutron-rich
isotopes at high beam energies ($\gtrsim$100MeV/u). The HRS consists of an
analysis beamline called the High-Transmission Beamline (HTBL) and the
spectrometer proper called the Spectrometer Section. The maximum magnetic
rigidity of the HRS is 8Tm, which corresponds to the rigidities at which
rare-isotope beams are optimally produced at FRIB. The resolving power, angular
acceptance, and momentum acceptance are set to match the anticipated scientific
program. An ion-optical design developed for the HRS is described in detail,
along with the specifications of the associated magnet and detector systems.
