Δn = 0 N-shell emission of rare earth ions (Z = 59 to 70) emitted from low and high density tokamak and laser produced plasmas

A discussion of the line and unresolved transition arrays emission of rare earths ions isoelectronic with PdI to CuI emitted from low (∼ 10¹³ cm⁻³) and high (∼ 10²⁰ cm⁻³) density tokamak and laser produced plasmas is presented. The spectra of prasaeodymium, europium, gadolinium, dysprosium and ytterbium have been excited in the TEXT tokamak plasma and recorded in the 50-200 Å range by means of a photometrically calibrated, time-resolving multispectral grazing incidence spectrograph. The prasaeodymium, samarium, gadolinium, dysprosium and ytterbium spectra obtained by focussing an Nd-glass laser beam on solid targets were recorded in the same spectral range on photographic plates. The relationship between the main plasma parameters, electron temperature and density, and the soft X-ray emission of rare earths is analyzed and discussed.