Parameters choosing for a time-of-flight momentum mapping system with truncated cone-shaped head

Based on the operating principle, we analyzed the restrictive interrelationship of the key parameters of the COLTRIMS (cold target recoil ion momentum spectroscopy)-type time-of-flight (TOF) momentum mapping system with truncated cone-shaped head. The analysis demonstrated how to appropriately choose and even optimize these parameters, the axial uniform magnetic field B  , the relative position of the differential aperture relative to the electrons source scsc and the aperture radius rcrc for the given energy range to be detected. The conclusion also showed that the cone-shaped head can be optimized by making a compromise between the relative position of the differential aperture relative to the electrons source scsc and the differential pumping effect according to the actual acceptance angle. The presented example gave a good demonstration for the conclusion.