Our understanding of plasma-based weaponry comes entirely from the alien materials recovered so far. The intact plasma-generating weapon recovered from the field has provided some incredible insights, and it's quite possible we could create a version suited for our own soldiers' use.
Our research into the alien's plasma based weaponry is among the most advanced and dangerous work we've undertaken so far. The most difficult question surrounding the use of plasma... how to maintain an adequate power supply in the field, was solved by the Elerium-based power cells recovered from the aliens. The heat sinks developed using their materials have also proven to be the answer to proper heat dissipation along the weapon's barrel. With this knowledge in hand, we should now be able to use any plasma pistols we've captured from the invaders, as well as begin manufacturing variants of our own design.