Relativistic Effects on Line Strengths Hydrogenic Isoelectronic in the for Transitions Sequence*

Rela ti vis ti c line s tre ngth s have been co mllU ted fo r a la rge num be r of tra ns iti ons us ing Dirac wave fun c t io ns for the u ne-e lec tro n, h ydruge n-lik e io ns . As ex pec te d . th e results ind ica te th a t re la t ivi s ti c effect s a re qUlt es ma ll fo r l.ow s tages of io ni zatio n . Howeve r , in ge ne ral , th ey a lso re ma in s maJi thro ughout ,~ la rge p orti o n of th e Isoelec tro nlc seque nce, beco min g typ ica ll y of th e orde r uf 10 pe rce nt in th e vIc init y of Z =50,. a ft e r whic h they gro w quit e rap idl y. T hi s s ugges ts th a t fo r multi e lec tro n io ns a basica ll y no n re la ti vis ti c theo ry mig ht we ll be ad eq ua te fo r li ght a to m is ue lec tro ni c iuns th ro u" h as muc h as 30 o r 40 s tages of io ni za ti o n. "