title: The addition of chromatic aberration coefficients.
abstract: The asymptotic chromatic aberration coefficients of electron lenses may be written as polynomials in reciprocal magnification. Expressions for the polynomial coefficients of a doublet are derived in terms of those of the individual members of the doublet.
authors.affiliation: CEMES-CNRS, B.P. 94347, 29 Rue Jeanne Marvig, F-31055 Toulouse cedex 4, France. hawkes@cemes.fr
authors.forename: P W
authors.initials: PW
authors.lastname: Hawkes