Gas flow rate influence on gas temperature regulation in a reinforced radio-frequency cross-field atmospheric pressure plasma jet

Radhika T P and Satyananda Kar
Department of Energy Science and Engineering,
Indian Institute of Technology Delhi, Hauz Khas, New Delhi-110 016, India
Dedicated to Prof P K Kaw

This study investigates the effect of gas flow rate on the gas temperature and discharge characteristics of a reinforced radio frequency cross-field atmospheric pressure plasma jet (APPJ) with an additional floating electrode. By introducing copper floating electrodes of varying widths, the plasma jet length, electron excitation temperature, electron density, and reactivity were enhanced. However, this enhancement was accompanied by an undesired rise in gas temperature, limiting the plasma’s application for heat-sensitive materials. To control this temperature rise, the gas flow rate varied from 1.5 to 9 lpm, showing a significant reduction in gas temperature from 438 K to 402 K as the flow rate increased, particularly at higher input powers. The study reveals that while an increase in gas flow rate initially improves ionization and reactivity by increasing electron excitation temperature and density, and then the insufficient input power for ionization at higher flow rates causes a decline in these parameters due to reduced ionization efficiency. Further optimization was achieved by increasing input power, which allowed better utilization of neutral atoms and improved plasma reactivity even at higher flow rates. The findings highlight the importance of tuning both gas flow rate and input power to maintain optimal plasma performance for various applications, particularly where controlled gas temperature and high reactivity are essential. © Anita Publications. All rights reserved.
Doi: 10.54955/AJP.34.3-4.2025.167-178
Keywords: Cold atmospheric pressure plasma, Atmospheric pressure plasma jet, Optical Emission spectroscopy.

Peer Review Information
Method: Single- anonymous; Screened for Plagiarism? Yes
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References

1. Bárdos L, Baránková H, Cold atmospheric plasma: Sources, processes, and applications, Thin Solid Films, 518(23) (2010)6705–6713.
2. Das S, Mohapatra S, Kar S, Physicochemical properties and antimicrobial efficacy of argon cold atmospheric pressure plasma jet activated liquids–a comparative study, Fundam Plasma Phys, 12(2024)100078; doi.org/10.1016/j.fpp.2024.100078.
3. Mallick A B, Prakash G V, Kar S, Narayanan R, Development of a pulse modulated sub-radio frequency power supply for atmospheric pressure plasma devices, Rev Sci Instrum, 94(2023)123508; doi.org/10.1063/5.0173873.
4. Rath S, Kar S, Microwave atmospheric pressure plasma jet: A review, Contrib Plasma Phys, 65(2024) e202400036; doi.org/10.1002/ctpp.202400036.
5. Winter J, Brandenburg R, Weltmann K D, Atmospheric pressure plasma jets: An overview of devices and new directions, Plasma Sources Sci Technol, 24(2015)064001; doi. 10.1088/0963-0252/24/6/064001.
6. Mahreen, Ganguli A, Prakash G V, Kar S, Sahu D, A 2D steady-state analytical model for atmospheric pressure RF plasma jet, Phys Scr, 98(2023)105011; doi. 10.1088/1402-4896/acf4cd.
7. Park J, Henins I, Herrmann H W, Selwyn G S, Hicks R F Discharge phenomena of an atmospheric pressure radio-frequency capacitive plasma source, J Appl Phys, 89(2001)20–28.
8. Kunhardt, Generation of large-volume, atmospheric pressure, nonequilibrium plasmas, IEEE Trans. Plasma Sci., 28(2000)189; doi.10.1109/27.842901.
9. Das S, Mohapatra S, Kar S. Elucidating the bacterial inactivation mechanism by argon cold atmospheric pressure plasma jet through spectroscopic and imaging techniques, J Appl Microbiol, 135(2024)lxae238; doi.org/10.1093/jambio/lxae238.
10. Walsh J L, Kong M G, Contrasting characteristics of linear-field and cross-field atmospheric plasma jets, Appl Phys Lett, 93(2008)111501; doi.org/10.1063/1.2982497.
11. Radhika T P, Kar S, Effect of an additional floating electrode on radio frequency cross-field atmospheric pressure plasma jet; Sci Rep,13(2023)10665; org/10.1038/s41598-023-37805-7.
12. Yue Y, Kondeti V S K, Sadeghi N, Bruggeman P J, Plasma dynamics, instabilities and OH generation in a pulsed atmospheric pressure plasma with liquid cathode: a diagnostic study, Plasma Sources Sci Technol, 31(2022)025008; doi. 10.1088/1361-6595/ac4b64.
13. Baek,and Eun Jeong, Effects of the electrical parameters and gas flow rate on the generation of reactive species in liquids exposed to atmospheric pressure plasma jets, Phys Plasmas,23(2016)073515; org/10.1063/1.4959174.
14. Wen Y, Economou D J, Gas flow rate dependence of the discharge characteristics of a helium atmospheric pressure plasma jet interacting with a substrate, J Phys D: Appl Phys,50(2017)415205; 10.1088/1361-6463/aa8794.
15. Li Q, Li J T, Zhu W C, Zhu X M, Pu Y K, Effects of gas flow rate on the length of atmospheric pressure nonequilibrium plasma jets, Appl Phys Lett,95(2009)141502; org/10.1063/1.3243460.
16. Jin D J, Uhm H S, Cho G, Influence of the gas-flow Reynolds number on a plasma column in a glass tube, Phys Plasmas,20(2013)083513; org/10.1063/1.4819246.
17. Li S-Z, Huang W-T, Wang D, The effect of gas flow on argon plasma discharge generated with a single-electrode configuration at atmospheric pressure  Plasmas,16(2009)093501; doi.org/10.1063/1.3223848.
18. Mahreen, Prakash G V, Kar S, Sahu D, Ganguli A, Excitation of helical shape argon atmospheric pressure plasma jet using RF pulse modulation, J Appl Phys, 130(2021)083301; doi.org/10.1063/5.0058000.
19. Qian M, Ren C, Wang D, Zhang J, Wei G Stark broadening measurement of the electron density in an atmospheric pressure argon plasma jet with double-power electrodes, J Appl Phys,107(2010)063303; doi.org/10.1063/1.3330717.
20. Mahreen, Ganguli A, Gajula V P, Kar S, Sahu D, A joint calibration technique for improving measurement accuracy of voltage and current probes during synchronous operation for RF-based plasma devices, Rev Sci Instrum. 93 (2022)123514; doi.org/10.1063/5.0124816.
21. Radhika T P, Kar S, Glow-to-arc discharge transitions in a radio frequency atmospheric pressure plasma jet, Phys Fluids,36(2024)084119; org/10.1063/5.0218872.
22. Shou-Zhe L, Huang W-T, Wang D, The effect of gas flow on argon plasma discharge generated with a single-electrode configuration at atmospheric pressure, Phys Plasmas,16(2009) 093501; org/10.1063/1.3223848.