A highly efficient numerical algorithm using the multigrid method (MGM) is
introduced to solve a three-dimensional (3-D) field distribution. Taking ad
vantage of the restriction and prolongation: in MGM computation, a more acc
urate field distribution can be acquired rapidly. According to the MGM algo
rithm, a 3-D program is accomplished, which can solve the field distributio
ns in electron optical systems for various electrostatic leases. The 3-D fi
eld distribution in an electrostatic concentric spherical model is tested w
ith the MGM algorithm and with an algorithm based on the finite difference
method (FDM). Comparing these two results in terms of computational efficie
ncy and computational accuracy, it appears that MGM is superior to FDM, whi
ch is now used the most in field computations. This paper shows that the 3-
D field computation using MGM greatly improves the computational efficiency
of field distributions in electron optical systems and shortens the comput
ational time.