Research, software, detector operations.

The paper — I'm the corresponding author

Measuring a background that matters for dark matter.

Radon leaks into every xenon detector, and its decay chain includes bismuth-214, which beta-decays into polonium-214. Those decays are one of the main backgrounds behind WIMP dark matter searches and neutrinoless double-beta decay searches, so we measured the shape of that decay precisely: the fraction that goes directly to the ground state (19.2%), up to its 3.27 MeV endpoint.

We built an algorithm to isolate clean ground-state decays from the ones accompanied by gamma rays, then compared the spectrum against several nuclear models. The conserved vector current (CVC) hypothesis fit best. As a side effect, the same dataset gave us a detector calibration up to the MeV scale — energies no other calibration source reaches.

Also presented as a talk at LIDINE 2025 in Hong Kong, and as a poster at the Neutrino 2024 conference in Milan.

The DAQ — I maintain this software

Getting every photon from the PMTs to the world.

XENONnT's data acquisition is triggerless: instead of deciding in real time what counts as an "event," it reads and stores every signal above threshold from all 698 photomultiplier tubes across the TPC, muon veto, and neutron veto, then reconstructs events afterward. During calibration it processes over 500 MB/s, and the collaboration has collected more than 2 petabytes of data this way.

I maintain the software behind that pipeline — the readout servers, the digitizers, and the event-building chain that streams data out for live monitoring and offline analysis, keeping the system above 99% livetime.