Rate of ionisation of H and Na Rydberg atoms by black-body radiation

Publisher Website
Google Scholar
Abstract
Formulae and tables for the evaluation of rates of ionisation of Na and H Rydberg atoms by black-body radiation are presented using the Herman-Skillman potential with a core polarisation correction for Na. It is shown that the ionisation rate, Rnl, can be written as Rnl=8.525*108(Enl/y exp(-Enly)l'=l+or-1 Sigma I(nl l't)/2l+1)s-1 where y approximately=157890/T, T in Kelvin, Enl=n*-2, n*=n- delta nl, delta nl being the quantum defect. The I(nl l't) correspond to Burgess's photoionisation integrals and vary slowly with t=T/104, n, l, and l'=l+or-1. Tables for hydrogen extend Burgess's results from n=20 to 40. Similar tables are presented for Na for n=10, 20, 30, and 40 and 77nl agree with those of Spencer for n=20, 25, and 30, T=77 and 300K for l=0 and 2. A new procedure for evaluating the I integrals over the Planck distribution is presented in an appendix. Tables of coordinates and weights for this quadrature are also given which allow one to do much less computing.