How do cosmic ray showers change with energy and particle type?

Physicists simulated cosmic ray collisions in Earth's atmosphere across three energies (10^15 to 10^17 eV) and three particle types (proton, helium, iron) to map how showers develop. Heavier nuclei create shallower showers by about 160 g/cm² at the highest energies, a measurable signature for composition studies. The results confirm decades-old predictions and establish a validated benchmark for cosmic-ray detectors.