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We report calculations of energies and decay rates for triply-excited 3131'31" configurations in Li-like N, N4+, and in B-like N, N2*, using a configuration interaction approach. Triply-excited configurations can be obtained in charge-exchange experiments and might be important in the process of neutralization of slow highly-ionized ions at surfaces but nearly no spectroscopic information is available for such states. We have found that there is a very strong configuration mixing in these systems which makes it difficult to give single-particle labels to the terms. This suggests that a molecular (collective) description might be useful in analogy with the molecular model of the doubly-excited nlnl' configurations in He-like spectra. Watanabe and Lin (1987) have considered a molecular description of the 3131'31" configurations in H e c We have considered whether this model is useful in the present case where the nuclear attraction is much stronger compared to the interelectronic repulsion but we do not find any compelling evidence for such a description. One of the motivations for the introduction of the collective model in the case of the doubly-excited states was the large difference between non-radiative decay rates for different states in these systems. However, we have not found evidence from the decay rates in the 3131'31'' configurations far a collective behaviour of the atomic shell. The 3131'31" configurations have many levels and can be difficult to resolve experimentally so average values are often more useful for comparison with experiment than rates for individual levels. We show that the average values of the decay rates, calculated assuming that there is no configuration interaction between the 3131'31" configurations, are in very good agreement with the correct average values even though configuration interaction is very strong. Since doublyexcited states of the type 3131' have a rather long lifetime we have suggested that multiply-excited states might be formed in the neutralization of slow highly-ionized ions at surfaces. We have found that triply-excited states have a considerably shorter lifetime and if additional electrons are added the lifetime seems to be reduced further so that this type of configuration can be responsible for the large number of low-energy electrons which are produced during a neutralization process. N Vaeck and J E Hansen

Experimental results of initial testing dye-laser "MILK-02' pumped by a copper vapor laser "Kulon-lO" are presented.Output parameters obtained are the following: average power -1 and 1.5 W, efficiency -17.6 and 18.7% at the wavelengths of 670 and 725 nrn, respectively. The laser apparatus is supposed to be used for methods of photodynamic therapy.