# Analysis of Rydberg Series of Ytterbium Monofluoride, YbF

## TL;DR

This paper uses advanced laser techniques to study the Rydberg states of YbF, leading to precise measurements of its ionization energy and molecular properties.

## Contribution

The study provides the most accurate ionization energy and rotational-vibrational constants for YbF+ using REMPI and PIRI techniques.

## Key findings

- The ionization energy of YbF is determined as 48706.57(8) cm–1.
- Rotational constants for YbF+ ground state are Bν=0+ = 0.257(1) cm–1 and Bν=1+ = 0.255(3) cm–1.
- The vibrational transition energy ΔG1/2 is confirmed as 598.86(15) cm–1 using PIRI.

## Abstract

Resonance-enhanced
multiphoton ionization (REMPI) is used to characterize
Rydberg states of 174YbF. Assignment of these Rydberg states
to series that converge to various rotational and vibrational levels
of the 174YbF+ cation leads to an accurate value
for the ionization energy IE = 48706.57(8) cm–1 of YbF. The values for the rotational constants of
the YbF+ X1Σ+ ground state
are found as B
ν = 0
+ = 0.257(1) cm–1 and B
ν = 1
+ = 0.255(3) cm–1, while the
vibrational transition energy is ΔG
1/2 = 598.86(15) cm–1. Photoinduced Rydberg ionization
(PIRI) measurements via a high-lying Rydberg state have been performed
using an infrared free electron laser, confirming the ΔG
1/2 value.