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Ion Clouds in the Inductively Coupled Plasma Torch: A Closer Look through Computations

“…Furthermore, in the regions of maximum Cu + ion density (i.e., where a maximum temperature of 10 200 K is reached), the local ionization degree is calculated to be more than 90%. This is again in agreement with the calculated results from ref , where the ionization degree at 10 000 K for copper is stated to be 91.8% and at 9500 K as 91.7%. The exact comparison is not possible because in ref , the injected analytes are diluted in water.…”

“…This is again in agreement with the calculated results from ref , where the ionization degree at 10 000 K for copper is stated to be 91.8% and at 9500 K as 91.7%. The exact comparison is not possible because in ref , the injected analytes are diluted in water. The maximum Cu 2+ ion density is about 7.5 × 10 13 m –3 , and the volume integrated density is around 3 × 10 13 m –3 (see Figure h).…”

“…This indicates that the ionization degree of Ar, at the position of maximum ionization (i.e., the position of maximum power coupling and maximum temperature, i.e., 10 200 K) is about 2.8%. This is in reasonable agreement with the calculated results from ref , where the ionization degree at 10 000 K for argon is stated to be 2.08% and at 9500 K as 1.20%. However, integrated over the entire torch region, the ionization degree of the Ar gas is about 0.033%.…”

“…LTE, in particular, has the advantage that the model can be more easily formulated consistently and it requires less other assumptions (e.g., on power coupling and energy transfer from electrons to atoms and ions) and/or (sometimes imprecise) parameters. Using the capabilities of LTE simulations for thermochemical processes in an ICP, Pupyshev et al calculated the formation efficiencies of singly and doubly charged ions of 84 elements within the temperature range of 4000–10 000 K by steps of 500 K, which showed good agreement with experimental data. Moreover, a two-temperature computational model for an rf ICP torch, applied to monatomic gases, indicated that deviations from LTE were relatively small at atmospheric pressure, i.e., within ∼5% for the bulk plasma, up to ∼10% for the areas close to the torch walls, but at reduced pressure substantial deviations from LTE were noted, i.e., ∼20–30%.…”

Atomic spectrometry update. Advances in atomic emission, absorption and fluorescence spectrometry and related techniques

“…A quasi-equilibrium model 219 has been used to calculate the formation of singly and doubly charged ions of 84 elements in the ICP, between 4000-10000 K, with the aim of improving the performance of semi-quantitative analysis in ICP-MS.…”