MEASUREMENT OF ATOMIC PARAMETERS OF SINGLY IONIZED ARGON LINES .1. EXPERIMENTAL PROCEDURE

In order to observe spectral lines of ArII, corresponding to transitio ns from levels of high excitation energy, and to have the highest poss ible temperature and free electron density in the applied light source , we have observed side-on the near cathode zone of an electric arc of I-arc = 200 A current, burning in pure argon at atmospheric pressure. Spectroscopic diagnostics of the observed zone showed that it was cha racterized by high temperature and electron densities of the order T a pproximate to 24,000 K and N-e approximate to 2 x 10(23) m(-3), respec tively. Altogether, we have registered more than 90 spectral lines fro m different levels and configurations, e.g. for which the upper levels belong to the 4 f configuration (excitation energy E(i) > 24 eV), 5 s and 3 d'' (E(i) > 22 eV). We were able to determine the transition pr obabilities of 92 ArII lines, relative to the 480.602 nm ArII line, an d Stark widths of some 80 ArII lines. Our transition probabilities and Stark widths for ArII lines, in many cases measured for the first tim er are consistent with the best data published up to now and give one of the most complete sets of results. In this first part, we present t he applied experimental procedure and characteristics of investigated argon levels. The transition probabilities and Stark widths of ArII li nes, measured in our experiments, are presented in the second and thir d part of this paper, respectively. (C) 1997 Elsevier Science Ltd.