I finally completed the 7×7 matrix, and looked for a way to test it. Are the trajectories drawn on the pixels really showing particle coming from the interaction of cosmic rays with earth atmosphere ?

Luckily I could place the matrix close to the Extremely Low ENergy Antiproton synchrotron (ELENA), at Cern. The annihilation of antiproton produces pions that might be an artificial source similar to what happens with natural cosmic rays.

Watch the video above and see how it works amazingly well. The pixels go crazy during the ELENA deceleration process as few antiprotons are lost on the vacuum pipe. And it is even more impressive when placed close to an extraction line.

Conclusion so far

I consider this hobby project as a draft, a proof of concept. But it seems reasonable to say we are tracing the trajectories of the shower of secondary particles created by cosmic rays, those high energy particles coming from space.