Asgard plasma beam weapon

"...the Apollo and the Daedalus have been retrofitted with the new Asgard plasma beam weapon which – given – are very, very powerful..."

- Dr. Rodney McKay

Plasma beam weapons are a newly developed technology created by the Asgard race shortly before their extinction. Instead of firing bursts of energy, plasma beam weapons release a narrow, high-intensity beam of super-heated plasma capable of penetrating even the most advanced shields.

These weapons were placed on the Odyssey as a gift to the Tau'ri in a mass upgrade, providing the ship with a means to effectively fight the Ori warships that had been invading the Milky Way galaxy. These weapons were eventually equipped on both the Daedalus and the Apollo, which used them to rapidly destroy the Aurora-class warships that the Asurans were deploying in the Pegasus Galaxy. In an alternate reality, these weapons were also equipped to the Phoenix, and used to destroy Wraith hive-ships in even fewer hits than Ori motherships and Aurora-class warships, as hive-ships possess no shields. These weapons have also proven capable of destroying Wraith cruisers, powerful ships in their own right, with just two well-placed shots.

Even warships as powerful as Ori motherships, the Aurora-class, and even Wraith hive-ships have yet to be able to mount an effective defense against these weapons. It is very probable, however, that the Shield of atlantis could resist thease weapons because of its ability to never detiriorate as long as sufficiant power exists (A ZPM could easily provide enough power.

It appears that the amount of power these weapons discharge is controllable, in cases where just destroying a small section of a ship to prevent an escape through hyperspace is necessary, but this could just be a case of precision aiming.