Journal article

Publication year: 2025

Journal: Journal of Electric Propulsion

Volume number: 4

DOI Link: https://doi.org/10.1007/s44205-025-00106-4

Publisher: Springer International Publishing

Abstract: 

Accurate characterization of plasmas within the discharge chambers of gridded ion engines is essential for their advancement. This study showcases the effectivity of terahertz time-domain spectroscopy (THz-TDS) as a non-invasive technique for profiling low-pressure inductively coupled plasmas, mimicking the conditions of the discharge chamber in a radio-frequency ion thruster. Operating at pressures of 3 -  mbar inside the discharge chamber and a supply power of the radio frequency generator ranging from 10 - 80 W, THz-TDS reveals electron densities in the range of -  m for xenon, krypton, and argon plasmas. Our results show good agreement with Langmuir probe measurements and global plasma modeling, highlighting the accuracy and reliability of THz-TDS. This validation, conducted under conditions representative of gridded ion engines, demonstrates that THz-TDS is, in principle, suitable for characterizing the electron system of the plasma ignited in such thrusters in operation. This offers great potential of developing a promising additional tool for plasma diagnostics in electric propulsion systems.

Harvard Citation style: Bräumer, K., Rodriguez, R., Stein, M., Keil, K., Holste, K., Becker, F., et al. (2025) Validating THz time-domain spectroscopy as a tool for characterizing low pressure inductively coupled plasmas of ion thrusters, Journal of Electric Propulsion , 4, Article 9. https://doi.org/10.1007/s44205-025-00106-4

APA Citation style: Bräumer, K., Rodriguez, R., Stein, M., Keil, K., Holste, K., Becker, F., Zorn, J., Wehkamp, K., Chatterjee, S., & Klar, P. (2025). Validating THz time-domain spectroscopy as a tool for characterizing low pressure inductively coupled plasmas of ion thrusters. Journal of Electric Propulsion . 4, Article 9. https://doi.org/10.1007/s44205-025-00106-4