Characterization of Two-Surface Multipactor with Non-Sinusoidal RF Fields

Multipactor is a generally undesirable nonlinear discharge occurring in vacuum RF components and systems in which an electron avalanche is sustained through secondary electron emission from metallic or dielectric surfaces in the presence of a high frequency RF field. We present the characterization of two-surface multipactor discharge with a non-sinusoidal Gaussian-type RF field waveform [1,2]. We employ Monte Carlo [3-5] and 3D electromagnetic Particle-in-Cell (PIC) [3] simulations to examine the effects of the amplitude, power, and full width half maximum (FWHM) of the Gaussian electric field on multipactor susceptibility and time dependent physics [3,5].



We observe that the threshold peak RF voltage and the threshold time averaged RF power per unit area for multipactor development increase with a Gaussian-type electric field compared to those with a sinusoidal electric field. The threshold peak RF voltage and RF power for multipactor increase as the FWHM of the Gaussian profile decreases. Decreasing the FWHM of the Gaussian electric field can reduce the electron population corresponding to the strength of the multipactor at saturation, at fixed time-averaged input power.

[1] D.-Q. Wen et al., Physics of Plasmas 26, 093503 (2019).

[2] D.-Q. Wen et al., Appl. Phys. Lett. 121, 164103 (2022).

[3] A. Iqbal et al., Phys. Plasmas 29, 012102 (2022).

[4] A. Iqbal et al., Phys. Plasmas 26, 024503 (2019).

[5] A. Iqbal et al., Physical Review E 102, 043201 (2020).