Role of the triplet metastable levels in ionization/excitation of palladium atom in glow discharge plasmas using several plasma gases

Metastable states in sputtered sample atoms: a tutorial review in perspective of elementary plasma processes

“…Then, they are compared with experimentally deduced OES results of Pd II by Wagatsuma. 35 These results are in good agreement with the calculated populations and conrm that for any selective excitation/ionization processes, the metastable levels of Pd would play a critical role. Knowledge of signicantly populated low-lying metastable levels is of great interest, which leads to a better understanding of the plasma processes and interpretation of the spectroscopy data.…”

“…Therefore, in the later case, it gives the additional possibility to satisfy the total electron spin conditions for the ACT process, e.g., in palladium. 35,36 A similar situation exists in chromium, 37 and also in copper metastable ions enhancing the population of doubly-excited copper neutral atoms. 38 So far, no systematic data appear to be available for considering collisional interaction between the plasma particles and metastable states of various transition metal atoms.…”

“…He has reported that the triplet metastable levels, i.e., 4d 9 5s 3 D 3,2,1 rather than the ground-state (4d 10 1 S 0 ) of the Pd atom play a critical role in excitations of the Pd II lines. 35 First, it should be noted that for the case of palladium, the multiplicity of the ground state atoms is different from the multiplicity of the metastable states of the palladium atom. Thus, if appropriate ionic energy levels of palladium are available, then the metastable states provide an additional opportunity to satisfy the required conditions for the selective ACT process.…”

Atomic spectrometry update: review of advances in atomic spectrometry and related techniques

“…The results showed that ions originated at the cathode with high energy which was lost collisionally during transit to the centre of the discharge. Wagatsuma 86 investigated ionisation and excitation of Pd in He, Ar, Ne and Kr GDs. The Pd II emission intensity correlated with the excitation energy of the plasma gases, with no intense emission observed in the Kr GD.…”