US particle detector goes underground to guard fusion plant water supplies

Jefferson Lab and Maryland startup Canary Instruments are adapting silicon photomultipliers (SiPMs) for underground tritium monitoring around commercial fusion plants. The Subsurface Continuous Radioisotope Environmental Monitor tracks soil and groundwater in real time to protect drinking water sources.

• Scintillator fibers buried in soil catch beta particles and send light to SiPMs
• SiPMs operate in strong magnetic fields and need very little power
• The tech was developed at Jefferson Lab and first used in GlueX and biomedical work
• Canary Instruments is running soil trials and talking to private fusion firms