EASII‑jet – non‑equilibrium electrodeless atmospheric secondary induced ionization plasma jet
Résumé
Non-equilibrium atmospheric pressure plasma jet (APPJ) devices are interesting plasma sources being under intensive development and studies over the last decade. Operating in ambient air, APPJs can be easy to design and to implement in to industrial systems. Their high potential to produce localized highly reactive oxygen and nitrogen species1,2 (RONS) is of significant interest in many fields of applications such as in liquid activation, agriculture and biomedical treatment. Typically made of a – transparent– dielectric tube of a few centimeters long, it is equipped with a pair of electrodes connected to a HV power supply. Noble gas (typ. He or Ar) flows into it at flow rate in the order of a liter per minute. The latter having a lower ionization energy threshold than air, ionization waves (IW) are generated, guided by the He plume outside of the tube forming a luminous plasma plume.
Taking advantage of the intriguing feature of IWs to be transferred across a dielectric layer up to a few mm3, electrodeless guided IWs can be produced and totally isolated from the power supply4,5. In this contribution, an original type of APPJ will be introduced. The dynamic of the secondary induced ionization waves is investigated experimentally using filtered iCCD imaging techniques, high-resolution optical emission spectroscopy and electrical measurements. Three operating modes have been identified depending on the HV excitation properties (voltage amplitude and pulse width). By changing from one mode propagation to another with respect to the pulse width duration, the elementary mechanisms will be discussed.
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2 S. Iseni, P.J. Bruggeman, K.-D. Weltmann, and S. Reuter, Appl. Phys. Lett. 108, 184101 (2016).
3 F. Pechereau and A. Bourdon, J. Phys. Appl. Phys. 47, 445206 (2014).
4 V.S. Johnson, W. Zhu, R. Wang, J. Lo Re, S. Sivaram, J. Mahoney, and J.L. Lopez, IEEE Trans. Plasma Sci. 39, 2360 (2011).
5 S. Iseni, A. Baitukha, N. Bonifaci, C. Pichard, and A. Khacef, Phys. Plasmas 27, 123504 (2020).