Description:
<jats:p>The 3-tube asymmetrical electrostatic unipotential lens was analyzed as was done with the symmetrical case. A reliable mathematical expression for the axial potential distribution was used to obtain the cardinal points and coefficients of spherical and chromatic aberration. The image and object side properties were obtained in each case. The values of S1/R and S2/R, the separations between the tubes, were taken equal to 0. 25, 0. 375, 0. 5, 0. 75, and 1. 00 and the length of the central electrode L/R was varied from 0. 25 to 2. 00 in steps of 0. 25. A comparison is made between the symmetrical and asymmetrical lens in the accelerating and decelerating modes.</jats:p>