Development of Trace Isotope Analysis using Resonance Ionization Mass Spectrometry based on Isotope Selection with Doppler Shift of Laser Ablated Atoms

Abstract

We have proposed a novel isotope selective RIMS concept, which can avoid Doppler broadening in solid sample direct measurement using LA-RIMS. We have succeeded in experimentally demonstrating the principle of our RIMS concept. Through the simulation in which the resonant ionization efficiency and the ion trajectory were calculated, we verified the advantages of the use of an electrostatic lens, such as improved sensitivity and system miniaturization. We confirmed that the selectivity of 4.5 × 10¹⁰ was achievable by adopting a triple excitation scheme and that the multistep ionization scheme was also usable in our method. We concluded that the new isotope selective LA-RIMS had adequate performance as a simple and high sensitivity analysis method for solid samples.

KEYWORDS:

• trace isotope analysis
• resonance ionization mass spectrometry
• laser ablation
• laser diode
• high resolution laser spectroscopy
• Doppler broadening
• isotope shift
• long-lived radionuclides