The weapon used by Worf was not directly named in the film, but the script of Star Trek: Insurrection  and the Star Trek Encyclopedia (4th ed., vol. 1, p. 378) identify it as one of the ten isomagnetic disintegrator mentioned by Worf earlier in the film. It was later partially identified by name when it appeared on Star Trek: Lower Decks.
According to the DecipherStarfleet Operations Manual, the isomagnetic disintegrator features a portable magnetic charge inducer which fires the beam of isomagnetic energy to disrupt the targets electromagnetic field. When used against lifeforms, the effect can be set anywhere from stun, to a temporary impairment of the central nervous system, and all the way up to the highest setting that disintegrates the target to dust.