X-ray laser
From Memory Alpha, the free Star Trek reference.
X-ray lasers were a type of ship-mounted weapon utilizing x-rays in the form of a laser emission. X-ray lasers were used by the Talarians in the 24th century.
The weapon was no match for Federation starships, like the USS Enterprise-D.
Endar, the Captain of the Talarian warship Q'Maire, powered up the weapons of his ship, neutral particle weapons, X-ray lasers and merculite rockets, in order to "convince" the crew of the Enterprise to return his adopted son, Jono. (TNG: "Suddenly Human")
