Optimization of a laser ion source for ¹⁶³Ho isotope separation

Area of Science:

• Nuclear Physics
• Particle Physics
• Atomic Physics

Background:

• The Electron Capture in Holmium-163 (ECHo) experiment requires radiochemically pure 163Ho for precise neutrino mass measurements.
• Ion implantation of 163Ho into calorimeters is critical for the ECHo experiment's success.

Purpose of the Study:

• To optimize the ion source unit for the ECHo experiment to meet stringent radiochemical purity requirements.
• To enhance the selectivity and efficiency of the 163Ho ion implantation process.

Main Methods:

• Utilized finite element method thermal-electric calculations to optimize thermal characteristics.
• Employed Gibbs energy minimization for chemical equilibrium simulations to refine material composition.
• Developed and implemented a 30 kV high transmission magnetic mass separator with a resonance ionization laser ion source.

Main Results:

• Achieved an improved selectivity of laser ionization over surface ionization, reaching 2700(500).
• Attained an overall efficiency of 41(5)% for the ion-implantation process.
• Optimized thermal characteristics and material composition of the ion source unit.

Conclusions:

• The optimized ion source unit significantly enhances the radiochemical purity of 163Ho samples for the ECHo experiment.
• Improved selectivity and efficiency of the ion implantation process are crucial for accurate electron neutrino mass determination.