Proton beam

A proton beam, proton burst and proton discharge were types of proton-based emissions from a directed energy particle weapon.

When the Borg assimilated Arctic One in 2153, they upgraded the ship with a proton burst weapon. 

In 2372, there were numerous anti-personnel proton dischargers hidden on the Kazon-Ogla training moon of Tarok. 

Ramuran tracer ships are armed with proton beams, which fire streams of tightly focused protons capable of penetrating any deflector shield regardless of modulation. Ensign Harry Kim likened the effect to being struck by thousands of needles. In 2374, he and the tracer Kellin became the first to develop a defense against proton beam weapons, by tying USS Voyager's baryon sensors into the deflector controls. This allowed the deflector to scatter the incoming beams, diminishing their effectiveness against the shields.