A SPECTROSCOPIC STUDY OF DOUBLE ELECTRON-TRANSFER FROM CU TO AR-III IN AN ECR-MICROWAVE DISCHARGE

We present spectroscopic measurements of rate coefficients for the population of the ArI 6 d[3/2]o and 8 s[3/2]o states by two electron transfer from sputtered Cu to Ar2+ in an ECR microwave discharge. Rate coefficients are obtained from absolutely measured line intensities using a modified corona model. Though the binding energies of these states differ by 8 meV only the probability of populating the 6 d level exceeds by a factor of ten that of populating the 8 s level. This is attributed to an energy resonance between the two electrons when promoting to their final levels. The cross section for this two electron transfer comes out to be of the order of 10-15 to 10-14 cm2. © 1990 Springer-Verlag.