Phaser emitter
A phaser emitter is a key component in starship and hand-held phasers. The emitter is equivalent to the "barrel of a gun", as it is the focal point where the phaser beam ("the bullet") is fired from.
Ship Mounted
From 2245 to 2270, ship mounted phaser emitters were built into the hulls of Star Fleet vessels and were operated in a control room by a small crew as a backup to bridge control.
In the 2270s phaser emitter designs had improved and the new design routed power directly from the warp engines which increased their effectiveness and strength. The only drawback was that if an antimatter imbalance occurred, the phasers would be automatically cut off.
Ship-mounted emitters are typically arranged into phaser banks. The normal arrangement is one or two emitters to a bank. Phaser banks and their emitters would later be replaced by phaser arrays in the 24th century on more modern starships. Smaller vessels such as shuttlecraft continued to use phaser emitters however.
Hand-weapons
Phaser emitters form part of the main component of hand phasers.