Revision of the ionization energy of neutral carbon

TL;DR

This paper presents a highly precise re-evaluation of neutral carbon's ionization energy using improved calibration data and advanced fitting techniques, significantly enhancing measurement accuracy.

Contribution

It introduces a new, more precise value for neutral carbon's ionization energy based on re-analyzed spectral data and improved calibration methods.

Findings

Ionization energy of neutral carbon: 90820.348(9) cm^{-1}

Enhanced measurement precision by a factor of nine

Predicted energies for unobserved states in the series

Abstract

This publication describes a re-analysis of previously published data on neutral carbon (C I) utilizing critically examined and improved values for the line energies of the absorption spectrum of molecular iodine to calibrate the transition energies of C I absorption lines originating from the 1s22s22p3s 3P{\deg}2) level and terminating on highly excited Rydberg states of the 1s22s22pnp 3D3 series, which converges on the first excited fine-structure level of the ionic ground configuration. Additional use of improved energy values for the 1s22s22p3s 3P{\deg}2 level, the fine-structure interval of the ionic ground state, and sophisticated modern fitting techniques lead to a new value of the ionization energy of neutral carbon with 9 times the precision of previous work, 90820.348(9) cm^{-1}, as well as a table of predicted values for the energies of not yet observed states in the series.