Visible and near UV M1 transitions within N-shell ground configurations of heavy ions predicted to be bright in low-density plasmas

We report results of a theoretical survey on the presence of intense long wavelength spectral lines in the near UV and visible spectral range arising from transitions within the 4pk (k=1-5) and 4p64dk (k=1-9) ground configurations in heavy ions. Ten such transitions with λ>1500 A were found in uranium ions. The density dependence of the corresponding line intensities is calculated for selected ions in the range 109-1018 cm-3. Based on previous experimental measurements in the UV spectral range, performed for similar transitions within M-shell ground configurations, it is expected that most of these lines would be sufficiently bright to be observed in future EBIT experiments, and in emission produced by other low density laboratory facilities. (orig.)