Influence of the nozzle head geometry on the energy flux of an atmospheric pressure plasma jet

Abstract

The influence of different nozzle head geometries and, therefore, the variation of the excitation and relaxation volume on the energy flux from an atmospheric pressure plasma jet to a surface have been investigated. Measurements have been performed by passive calorimetric probes under variation of the gas flow through the nozzle. The results show that the geometry of the nozzle head has a significant impact on the resulting energy flux. The relaxation volume affects the dependence of the energy flux on the gas flow. While there is no significant influence of the working gas flow on the energy flux without a relaxation volume, utilizing a relaxation volume leads to a decrease of the energy flux with increasing working gas flow. Within the analyzed parameter range, the energy flux reveals for both nozzle heads a linear dependency on the applied primary voltage.

A Simple and Compact Laser Scattering Setup for Characterization of a Pulsed Low-Current Discharge

“…Apart from the references summarized in Table 1, several research groups analyzed plasma systems comparable to the one studied here [51,53,[74][75][76][77], though only few have determined the temperature of the effluent plasma jet using emission spectroscopy. Kubota et al spectroscopically analyzed a comparable plasma system operated at a pulse frequency of 19 kHz, with nitrogen flowing at 30 L/min [74].…”

Spectroscopic Characterization of a Pulsed Low-Current High-Voltage Discharge Operated at Atmospheric Pressure

“…Furthermore, due to the ratio of the sensor size to the measured object size, this method only allows the recording of integral values. Therefore, spectroscopic measurements or laser scattering diagnostics should be preferred over thermocouple-based ones for the evaluation of the heavy particle temperature T h with regard to the chemical reactivity of the plasma under study, while calorimetric measurements as presented in [39,40] are preferable if the thermal load of the substrate is to be evaluated.…”

“…As mentioned in section 1, several researchers have analyzed spectroscopically compa-326 rable plasma systems to the one studied here [3,24,35,36,40,41], but none have determined 327 the electron number density purely experimentally using hydrogen line broadening. Some, 328 as will be discussed in the following, calculated the electron density based on recorded 329 molecular spectra.…”