I had a rethink on the suggestion on naming above, taking away the real world science elements, a few came up like this.

Blaster: Pulsing 'laser'. I'm a bit hesitant to call them blasters though.

Pulse (Gun): Energy needle rapid firing weapon.

Beamer: A 'laser' beam/phaser type weapon.

Accelerator: A powerful kinetic weapon.

Lance/Lancer: A powerful beam/stream type weapon.

Arc (Gun): A sort of lightning generator.

Devastator: Fires big globs of energy (Plasma?).

Given it doesn't take place in the 'same' universe as modern earth (Although there is a bit of a story of humanity leaving the 'homeworld' several millennia ago, but its name has long been forgotten), some newer more ambiguous naming might work ok.

@undefined How about some kind of nuclear powered weapon that would do even more damage then a normal nuclear warhead. Like have the weapon shoot out a highly radioactive slag/round. The first impact breaks the shields then a secondary explosion happens creating a radioactive pulse that damages not the the ship the the ones inside as well if the ship don't have some type of radiation protection.