TRIUMF Develops Accelerator-Driven Ion Source to Test Barium-Tagging Techniques for Neutrinoless Double Beta Decay Detection
Researchers at TRIUMF are commissioning an accelerator-driven barium ion source to test and optimize Ba-tagging techniques for the nEXO experiment, which searches for neutrinoless double beta decay in xenon-136. Ba-tagging would identify daughter barium nuclei from decay events, allowing researchers to distinguish true decay signals from background noise. This development is crucial for increasing the sensitivity of future neutrinoless double beta decay searches, which could reveal physics beyond the Standard Model.
The nEXO experiment aims to detect neutrinoless double beta decay (0νββ) in a tonne-scale liquid xenon time projection chamber, with a projected half-life sensitivity exceeding 10²⁸ years over 10 years of operation. To improve the experiment's ability to suppress backgrounds and increase sensitivity, researchers are pursuing Ba-tagging—a technique that extracts and identifies the barium-136 daughter nucleus produced when xenon-136 undergoes double beta decay. An accelerator-driven ion source currently under development at TRIUMF will inject radioactive barium ions into liquid xenon, where they will be collected electrostatically and detected via gamma spectroscopy. This facility will enable different research groups to test, quantify, and optimize various extraction and identification methods for Ba-tagging. The commissioning update represents progress toward a critical tool for validating background-suppression techniques in the search for physics beyond the Standard Model.
What's missing
The study does not discuss the timeline for completing the ion source commissioning, the specific physics implications if neutrinoless double beta decay is detected (such as constraints on neutrino mass or Majorana nature), or how Ba-tagging compares quantitatively to other background-suppression methods being pursued by the nEXO collaboration.
What different sources said
- arXiv physicsCenter
Experimental updates on development of accelerator-driven ion source at TRIUMF to benchmark Ba-tagging techniques for future neutrinoless double beta decay searches
Related
Topology-Aware Thermodynamics Improves DNA Probe Specificity Design
Researchers developed a new framework for designing DNA probes that accounts for the spatial organization of matched sequences, not just overall thermodynamic stability. Traditional methods rely on scalar measures like melting temperature and free energy, which miss how mismatches are distributed along the probe. The approach could improve diagnostic accuracy in applications like HPV detection and gene expression profiling.
Study Identifies Optimal Thermal Dose for Combining Focused Ultrasound with Immunotherapy in Tumors
Researchers used multimodal PET imaging to identify an optimal thermal dose range for focused ultrasound ablation that destroys tumor tissue while preserving conditions for immunotherapy delivery. The study found that excessive heating collapses blood vessels needed for antibody access, while insufficient heating fails to adequately reduce tumor burden. The findings could guide clinical design of combination treatments pairing thermal ablation with immunotherapies.
Plant MSH1 Protein Functions as Mismatch-Directed Nuclease for Organelle Genome Maintenance
Researchers have identified the precise mechanism by which the AtMSH1 protein in Arabidopsis plants recognizes and cleaves DNA mismatches and lesions, preventing mutations in organellar genomes. The protein combines a DNA mismatch recognition module with a nuclease domain that makes staggered cuts at specific positions relative to DNA damage. This discovery explains how plants maintain unusually low mutation rates in their mitochondrial and chloroplast DNA compared to other eukaryotes.