Wide aperture multipole magnets of the kinematic separator COMBAS. Analyzing multipole magnets M2 and M7 with compensation for higher order aberrations

The high-resolving large aperture kinematic separator COMBAS has been created and commissioned. The magneto-optical structure of separator is based on the strong focusing principle. The separator consists of eight wide aperture multipole magnets M1-M8. In part, the separator includes bending multipole magnets M2 and M7 having quadrupole, sextupole and octupole components in their field distributions. The presence of these components allowed one to intensify focusing without separate quadrupoles, minimize spherical aberrations and compensate for chromatic effects. Three-component magnetic field measurements on the surface of a closed volume have been performed for the magnets M2 and M7. These measurements allowed one to analyze the magnet manufacturing quality. The measured data will allow one to compile 3D-maps of magnetic fields. The 3D-maps of the magnetic field are supposed to be used for the particle trajectory simulations throughout the separator