The heavy graviton beam was a type of graviton beam.
A heavy graviton beam was proposed in 2367 during research by Chief Engineer Geordi La Forge and Lieutenant commander Elizabeth Shelby for use against a Borg cube. The proposal was rejected after La Forge, who went over the weapon's effectiveness four times, came to the conclusion that the local field dispersion would not be strong enough to incapacitate the cube's defenses. (TNG: "The Best of Both Worlds, Part II")