Microwave method based on curve fitting method for high-precision collision frequency diagnosis

Ma, Gelu; Liu, Yanming; Zhao, Chengwei; Sun, Chao; Bao, Weimin

doi:10.1088/2058-6272/ac630c

Cited by 2 publications

(1 citation statement)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The microwave interferometry and the transmission methods [20][21][22][23][24] obtain the average electron density on the propagation path and have the advantages of not interfering with the flow field, a wide dynamic range, and a precise time resolution. Among these methods, microwave interferometry measures the phase difference between the signal transmitted through the plasma and the reference signal without plasma.…”

Section: Introductionmentioning

confidence: 99%

Diagnosing ratio of electron density to collision frequency of plasma surrounding scaled model in a shock tube using low-frequency alternating magnetic field phase shift

Wu 吴,

Xie 谢,

Liu 刘

et al. 2024

Chinese Phys. B

View full text Add to dashboard Cite

A non-contact low-frequency (LF) method for diagnosing the plasma surrounding a scaled model in a shock tube is proposed. This method utilizes the phase shift occurring after the transmission of an LF alternating magnetic field through the plasma to directly measure of the ratio between the plasma loop average electron density and collision frequency. An equivalent circuit model is used to analyze the relationship between the phase shift of the magnetic field component of LF electromagnetic waves and the plasma electron density and collision frequency. The applicable range of the LF method at a given plasma scale is analyzed. The upper diagnostic limit for the ratio of the electron density (units: m-3) to collision frequency (units: Hz) exceeds 1 × 1011, enabling an electron density exceeding 1 × 1020 m-3 and a collision frequency less than 1 GHz. The paper also assesses the feasibility of using the LF phase shift for plasma diagnosis. Diagnosis experiments were conducted on shock tube equipment using both the electrostatic probe method and LF method. By comparing the diagnostic results of the two methods, the inversion results were relatively consistent, thereby providing preliminary evidence for the feasibility of the LF method. The ratio of the electron density to the collision frequency has a relatively uniform distribution during the plasma stabilization time. The LF diagnostic path is a loop around the model, which is suitable for diagnosing the plasma that surrounds the model. Finally, the causes of diagnostic differences between the two methods are analyzed. The proposed method provides a new avenue for diagnosing high-density enveloping plasma.

show abstract

Section: Introductionmentioning

confidence: 99%

Diagnosing ratio of electron density to collision frequency of plasma surrounding scaled model in a shock tube using low-frequency alternating magnetic field phase shift

Wu 吴,

Xie 谢,

Liu 刘

et al. 2024

Chinese Phys. B

View full text Add to dashboard Cite

show abstract

A diagnostic method of radial electron density distribution based on microwave transmission of cylindrical plasma along multipath

Zhao,

Li,

Gao

et al. 2024

Physics of Plasmas

View full text Add to dashboard Cite

Based on the multipath propagation phase shift of electromagnetic wave in cylindrical plasma, a method to obtain the radial electron density distribution of non-uniform cylindrical plasma is proposed in this paper. Focused lens antennas are used in multipath transmission distribution diagnosis (MTDD), where the propagation area in the plasma is approximately the size of the focal spot. The equivalent propagation thickness at each layer can be calculated for each path based on the propagation region and layer thickness. Combining with Fermat's shortest wavelength principle, electromagnetic waves propagate in a straight line between different layers. The phase shift caused by the propagation of electromagnetic waves in each layer, starting from the outermost layer, can obtain layer by layer electron density. To validate the MTDD method, multipath transmission propagation phase shift was simulated in CST, and the electron density distribution was obtained, which has a good agreement with the preset electron density. In addition, the MTDD method was applied to inductively coupled plasma, and the diagnostic results showed high agreement with the Langmuir probe results. The proposed MTDD method has higher spatial resolution than the transmission diagnosis method and can provide more precise plasma parameter information.

show abstract

Microwave method based on curve fitting method for high-precision collision frequency diagnosis

Cited by 2 publications

References 25 publications

Diagnosing ratio of electron density to collision frequency of plasma surrounding scaled model in a shock tube using low-frequency alternating magnetic field phase shift

Diagnosing ratio of electron density to collision frequency of plasma surrounding scaled model in a shock tube using low-frequency alternating magnetic field phase shift

A diagnostic method of radial electron density distribution based on microwave transmission of cylindrical plasma along multipath

Contact Info

Product

Resources

About