A dense piece of plastic the size of a coin flashes when an invisible particle hits it. That's how scintillators work — materials that turn radiation into faint light. They're usually made from fragile crystals or expensive polymers. But now there's a simpler option: plain polyurethane, the stuff used to mold furniture foam and shoe soles.

In the lab, researchers took two polyurethane formulations — old M600 and new M700—and compared them with proven plastic detectors EJ-276D and EJ-200. All samples were identical: disks 26 millimeters in diameter and 10 millimeters tall. They were glued to a photomultiplier tube, a device that amplifies single flashes into an electrical signal. Then they were irradiated with a mix of neutrons from californium-252 and gamma rays from cesium-137. Neutrons and gamma quanta leave different-shaped flashes in the plastic, and a good detector must tell them apart.

Then all samples were artificially aged: heated and held under harsh conditions to speed up time. The ordinary plastics turned cloudy afterward: their optics degraded. The polyurethane ones stayed clear. True, the accelerated aging was short, and no material showed a noticeable drop in performance. But the trend is clear: polyurethane is tougher.

This matters for hospitals and factories, where detectors work for years in dust, vibration, and temperature swings. Tough, cheap polyurethane could replace expensive crystals in scanners, dosimeters, and baggage screening systems. Light born from radiation can now be caught by a plastic that doesn't mind a knock.