Swiss researchers build camera-like detector that tracks invisible particles in 3D

A new kind of particle detector could replace millions of tiny components with a single block of light-producing material, Swiss researchers say.

Researchers at ETH Zurich and EPFL have built and tested the first prototype of PLATON, a detector designed to perform ultrafast, high-resolution 3D imaging of elementary particles inside a large, unsegmented block of scintillator, according to the ETH Zurich Department of Physics (https://www.phys.ethz.ch/news-and-events/d-phys-news/2026/04/neutrinos-caught-on-camera.html). The work was led by Professor Davide Sgalaberna with PhD student Till Dieminger and senior scientist Dr. Saúl Alonso-Monsalve, in collaboration with EPFL's Advanced Quantum Architecture Lab under Professor Edoardo Charbon, ETH Zurich reports.

Conventional detectors are divided into vast numbers of small active sections — the T2K experiment in Japan, for example, uses about two million cubes and 60,000 fibers, according to ScienceDaily (https://www.sciencedaily.com/releases/2026/07/260716023610.htm). PLATON instead borrows light-field, or plenoptic, camera technology: a micro-lens array sits in front of a single-photon avalanche diode (SPAD) sensor called SwissSPAD2, developed at EPFL, to reconstruct where faint flashes of light originated inside the scintillator, ScienceDaily reports. The sensor adds gated photon detection, recording only within defined time windows to filter out background noise.

In laboratory tests, the team tracked light levels from several hundred photons down to just five, and used a strontium-90 source to produce electrons whose positions they reconstructed inside plastic scintillator, according to ETH Zurich. The researchers also trained a neural network — a Transformer architecture adapted from large language models — to examine patterns among the recorded photons and reconstruct the original particle interaction, ScienceDaily reports.

Simulations suggest an unsegmented PLATON cube of 10×10×10 cm could reach spatial resolution below 1mm and identify neutrino interactions producing low-momentum protons with high purity and efficiency, according to ScienceDaily. The team estimates a one-cubic-meter version could achieve resolution of a few millimetres — on par with today's best segmented detectors — without the manufacturing and cost burden of millions of individual parts, ETH Zurich reports. The results were published in Nature Communications (https://www.nature.com/articles/s41467-026-70918-x).

The Swiss National Science Foundation funds the PLATON project, according to both institutions. Beyond physics, the ETH Zurich researchers have filed three patents applying the approach to positron emission tomography (PET) scanners, they say.

*Source Reporters corrects errors promptly. Report corrections to corrections@sourcereporters.com.*