eng Science and Education Publishing International Journal of Physics 2333-4576 2016-09-09 4 5 130 134 10.12691/ijp-4-5-3 IJP2016453 article Mohammed A. Hussein mohdphy@yahoo.com 1 Department of Mechanization and Agricultural Equipment, University of Kirkuk, College of Agriculture / Hawija The research aims to study the effect of changing the geometric shape of the poles and the distance between them on the focal properties in the condenser magnetic lens and thus the efficiency of the scanning electron microscope through its impact on the amount of miniaturization in the electronic beam passers-through optical column system lenses as well as the amount of aberrations that contribute to reducing the clarity and precision in the resulting image for the sample to be tested. We used six condenser lenses equal in the internal and external geometry and the length of the lens as well as for the coil area and vary the poles and the distance between them to get out the best model. http://pubs.sciepub.com/ijp/4/5/3/ijp-4-5-3.pdf condenser lens scanning electron microscope thermionic emission scanning electron microscope ray tracing