Three dimensional TOSCA calculations on the TRIUMF second arm spectrometer magnet

The design of the TRIUMF Clamshell Second Arm Spectrometer Magnet (SASP) and the associated field clamps have been reported. Since this magnet cannot be well approximated by two dimensional models due to the greatly different median plane (y = 0) cross sectional area of the two yoke spacers and due to the curvature of pole edges at the beam entrance and exit, three dimensional calculations are needed. The programs SCARPIA-TOSCA-OPERA(1) have been used to calculate the three dimensional fields produced by a clamshell dipole magnet. Results are presented for models of the complete magnet, for models of the entrance and exit regions and for models of the entrance and exit regions including field clamps