Ionization rate vs. laser intensity determined from ion count vs. peak intensity due to neutral gas exposure to an 800 nm ultrashort pulsed laser

Edward L. Ruden

atomic physics

Ionization rate vs. laser intensity determined from ion count vs. peak intensity due to neutral gas exposure to an 800 nm ultrashort pulsed laser

arXiv:2508.07500

summary

The paper determines the optical-cycle-averaged ionization rates of Ar, O₂, and N₂ as functions of instantaneous 800 nm laser intensity up to ~300 TW/cm² by numerically inverting published time‑of‑flight ion spectrometer data and recalibrating microchannel‑plate collection efficiencies.

Abstract

The optical cycle-averaged ionization rate of Ar, O $_{2}$ , and N $_{2}$ vs. local instantaneous laser intensity $I$ for linear polarized $800$ nm light is determined up to approx. $300$ TW/cm $^{2}$ by numerically inverting published time-of-flight ion spectrometer data. The published Ar $^{+}$ collection efficiency of the microchannel plate (MCP) at the end of the spectrometer and its $I_{0}$ scale are recalibrated by fitting it to its high $I_{0}$ solution. The relative collection efficiencies of the other species are determined by published MCP cathode data. Results for O $_{2}$ are consistent with a reevaluation of published data used to determine its cross section $I ¨ _{8}$ in the multiphoton (low $I$ ) regime.

10 pages, 8 figures/subfigures. Journal submission pending

Topics & keywords

#ionization rates #ultrashort laser pulses #time-of-flight spectroscopy #microchannel plate calibration #multiphoton ionizationionization ratelaser intensity800 nm ultrashort pulsetime-of-flight ion spectrometermicrochannel platemultiphoton ionizationArO₂N₂