A spectral study of charge transfer and Penning processes for Cu, Zn, Ag, and Cd in a glow discharge

Glow discharge excitation and matrix effects in the Zn–Al–Cu system in argon and neon

“…Emission yields of all Zn II lines in neon are much higher than in argon, by a factor of 30-140, in agreement with the results of Zhao and Horlick [6]. Enhancement factors (ratios of emission yields) are very similar for the transitions starting from the same upper level, which is in conformity with the idea that the ratio of emission yields of the same line at different conditions reflects the ratio of the populations of the upper level [3] and indicates a good precision of the measurements.…”

“…The magnitude of the enhancement of all Zn II lines, together with the difference between the two lines originating from 5s 2 S 1/2 level and the other Zn II lines, suggests that, by far the most effective excitation mechanism of the zinc ionic lines observed in these experiments is an ACT reaction between zinc atoms and the Ne + ions, populating the 4d 2 D levels of the zinc ion. Cascade deexcitation of these levels via 4p 2 P 0 to the ground state of the zinc ion is responsible for the high enhancement factors observed for the five Zn II lines on the way, as suggested by Weiss [5] and Zhao and Horlick [6].…”

“…[4], but in both discharge gases: emission yields of Zn II lines are smaller for ZnCu alloys than ZnAl, by a factor of about 0.5 in an argon discharge and about 0.65 in neon. Copper is ionized by ACT not only by argon ions but also by neon [6,25], hence, the earlier suggested explanation [5] of these matrix effects by quenching of the gas ions available for the ionization of zinc by the ACT reaction with copper may be applicable to the neon discharge as well as argon. Unlike argon, neon can ionize also aluminium by ACT, hence, the key question will be how efficient copper is, relative to aluminium, in quenching the Ne + ions.…”

“…Weiss attributed this to de-excitation of the ACT-excited levels down to the ground state of the zinc ion, followed by non-selective excitation by collisions with electrons to different excited levels and subsequent cascade deexcitations [5]. Independently and at about the same time, cascade de-excitation of the Zn II levels was described by Zhao and Horlick [6] for He-Zn and Ne-Zn discharges. This paper is an extension of the studies mentioned above and involves comparison between argon and neon discharges in the analysis of Zn-Cu-Al alloys.…”

Deviation from Normal Boltzmann Distribution of High-lying Energy Levels of Iron Atom Excited by Okamoto-cavity Microwave-induced Plasmas Using Pure Nitrogen and Nitrogen–Oxygen Gases

“…It is known that this effect can be observed predominantly in argon glow discharge plasmas, in which a Penning-type ionization with argon metastable atom occurs to a larger extent compared to the direct ionization by electron collision. [20][21][22] An excitation temperature was estimated from a slope of the linear part, the excitation energy of which ranged from 3.4 to 4.8 eV in the Boltzmann plot. Figure 5 shows variations in the excitation temperature as a function of the forward microwave power in the pure nitrogen Okamoto-cavity MIP.…”