LOW-TEMPERATURE RADIATIVE RECOMBINATION OF ELECTRONS WITH BARE NUCLEI

Aside from empirical formulas, the radiative-recombination cross secti on and coefficient are usually given in tabulated forms instead of ana lytic formulas. Here, we give analytic expressions in the form of expa nsions for the recombination cross section as a function of the electr on energy E for low E, and for the recombination coefficient as a func tion of the temperature T for low T. The expansion coefficients are co mbinations of confluent hypergeometric functions, and are tabulated fo r a large number of the final principal and angular-momentum quantum n umbers n and l. It is shown that the recombination cross section for a rbitrary nuclear charge number Z is independent of Z, while the recomb ination coefficient for T/Z2 much lees than 1. 58 X 10(5) K increases as Z2. Excellent agreement is found with the published tabulated value s.