| Autor: |
Kim, Kyungtae, Nam, Woojin, Lee, Jimo, Shim, Seungbo, Yun, Gunsu S. |
| Rok vydání: |
2022 |
| Předmět: |
|
| DOI: |
10.48550/arxiv.2203.00420 |
| Popis: |
We discovered a hysteresis in a microwave-driven low-pressure argon plasma during gas pressure change across the transition region between $��$ and $��$ discharge modes. The hysteresis is manifested in that the critical pressure of mode transition depends on the direction of pressure change. As a corollary, the plasma would attain different discharge properties under the same operating parameters (pressure, power, and gas composition), suggesting a bi-stability or existence of memory effect. Analysis of the rotational and vibrational temperatures measured from the OH (A-X) line emissions shows that the hysteresis is mainly due to the fast gas heating in the $��$-mode leading to a smaller neutral density than that of the $��$-mode. When increasing the gas pressure, the $��$-mode discharge maintains a relatively higher temperature and lower neutral density, and thus, it requires a higher operating pressure to reach the $��$-mode. On the other hand, decreasing the pressure while maintaining $��$-mode, the transition to $��$-mode occurs at a lower pressure than the former case due to a relatively higher neutral density of $��$-mode discharge. This interpretation is supported by the fact that the hysteresis disappears when the plasma properties are presented with respect to the neutral gas density instead of pressure. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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