AEgIS Experimenters Turn the Humble Smartphone Camera Into a Gigapixel Antimatter Snapper

Researchers working on the Antihydrogen Experiment: Gravity, Interferometry, Spectroscopy (AEgIS) project at the European Organization for Nuclear Research (CERN) have found a surprisingly low-cost device that can deliver "unprecedented" resolution for antimatter photography: the humble smartphone camera sensor.

"For AEgIS to work, we need a detector with incredibly high spatial resolution, and mobile camera sensors have pixels smaller than one micrometer," explains principal investigator Francesco Guatieri. "We have integrated 60 of them in the single photographic detector, the Optical Photon and Antimatter Imager (OPHANIM), with the highest number of pixels currently operational: 3,840 [megapixels]. Previously, photographic plates were the only option, but they lacked real-time capabilities. Our solution, demonstrated for antiprotons and directly applicable to antihydrogen, combines photographic-plate-level resolution, real-time diagnostics, self-calibration, and a good particle collection surface, all in one device."

That smartphone image sensors improve every generation is no secret: in only a couple of decades phone cameras have gone from blurry, sub-VGA resolution snapshots to multi-megapixel images capable of going toe-to-toe with dedicated camera hardware — but using them to take snapshots of antimatter is something their manufacturers have probably not considered. Combining 60 commercial sensors on a custom-built antimatter camera the team showed that it's possible to capture low-energy positrons in real-time at a resolution high enough to be useful in the AEgIS experiment, in which a beam of antihydrogen is produced and its vertical displacement measured using a moiré deflectometer.

If you're interested in taking your own antimatter images, though, it's not quite as straightforward as pointing your smartphone at an antihydrogen source — assuming you have access to one in the first place. In order to adapt the sensors, they required careful hardware modification. "We had to strip away the first layers of the sensors, which are made to deal with the advanced integrated electronics of mobile phones," Guatieri explains. "This required high-level electronic design and micro-engineering."

"This is a game-changing technology for the observation of the tiny shifts due to gravity in an antihydrogen beam traveling horizontally, and it can also find broader applications in experiments where high position resolution is crucial, or to develop high-resolution trackers," claims AEgIS spokesperson Ruggero Caravita of the team's creation. "This extraordinary resolution enables us also to distinguish between different annihilation fragments, paving the way for new research on low-energy antiparticle annihilation in materials."

The team's work has been published in the journal Science Advances under open-access terms.

Main article image courtesy of Andreas Heddergott/TUM.