New Resonance Ionization Mass Spectrometry Scheme for Improved Uranium Analysis

Area of Science:

• Analytical Chemistry
• Atomic Physics
• Materials Science

Background:

• Resonance ionization mass spectrometry (RIMS) is a powerful technique for analyzing solid materials.
• Previous RIMS methods achieved a 24% useful yield for uranium analysis using three lasers.
• Molecular ion formation (UOx) is a significant challenge in uranium dioxide analysis.

Purpose of the Study:

• To develop a more efficient RIMS technique for uranium analysis.
• To enhance the useful yield for uranium and uranium dioxide.
• To overcome challenges associated with molecular ion formation during sputtering.

Main Methods:

• Implemented a novel two-laser resonance ionization scheme targeting ground and low-lying electronic states of uranium.
• Employed prebombardment with 3 keV noble gas ions to reduce uranium dioxide surfaces.
• Analyzed sputtered atoms from metallic uranium and uranium dioxide using RIMS.

Main Results:

• The new two-laser scheme achieved a 38% useful yield for uranium, surpassing the previous 24% yield.
• Surface reduction via prebombardment increased uranium useful yields for uranium dioxide to 6.6% from 2%.
• Reduced UOx molecular ion formation was observed after surface prebombardment.

Conclusions:

• The optimized two-laser RIMS approach significantly enhances uranium atom detection efficiency.
• Surface prebombardment is an effective strategy to mitigate molecular ion interference in uranium dioxide analysis.
• This improved RIMS methodology offers higher sensitivity and accuracy for uranium isotopic analysis.